air engine - murdoch research repository · air engine thesis 2016 2 declaration i declare that...

ENG470 ENGINEERING HONOURS THESIS

AS A REQUIREMENT FOR THE COMPLETION OF THE BACH. OF ENGINEERING(HONS) AT

MURDOCH UNIVERSITY FOR INDUSTRIAL COMPUTER SYSTEMS/INSTRUMENTATION

AND CONTROL ENGINEERING.

School of Engineering & Information Technology

Prepared by: Abdul Razak Ibrahim

Academic Supervisor: Associate Professor Graeme Cole

June 2016

Air Engine

Air Engine Thesis 2016

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Dedication I dedicate this report and project to my family for their moral support and my sponsor Majlis

Amanah Rakyat (MARA) for their financial support. Also, my friends for sharing the knowledge and

ideas during the implementation of this project. Thank you.

Acknowledgement I would like to acknowledge the great help from a staff member at the Department School of

Engineering and Information Technology. Especially to Mr. John Boulton and Mr. Iafeta Laava (Jeff)

for being a handyman, and prepare the tool and equipment used for replacement and installation,

also included Mr. Will Stirling for his help with IT. I also recognize my classmates those are made

meaningful contribute towards the success of this project.

Most importantly, my great supervisor Associate Professor Graeme Cole for his incredible patience

and tireless effort with my terrible organizational skill. I would not have been able to complete this

project and got this far in engineering without the help and support from them.


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Declaration I declare that this report is my effort, and it has never presented before elsewhere. I have ensured to

the best of my knowledge that all information sources from secondary sources have been cited and

acknowledged duly as required. If there are any omissions noted herein, they are not intentional in

any way, and corrections for this report are welcome.

Student Sign………………………

Date…………...……………………


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Abstract The Murdoch University Air Engine project was built for Industrial Computer System Engineering

(ICSE) students to implement and fundamentally develop a significant understanding of the 68HC11

Microcontroller. This system was developed and designed by third-year undergraduate students for

their project with the help of Murdoch University’s technician and electrician staff for installation of

hardware equipment and information technology (IT) related task. This project is a learning tool that

provides hands-on experience with industrial-grade equipment and the environment. This also

includes maintenance and improvement of its functionality as a part of the on-going thesis project.

Air Engine was one of the first engine designs that helped to introduce the concept that an engine

can be used to run a vehicle. Throughout the years, different designs have been implemented, and

some of them were successful such that they were utilized in the powering vehicles. Also, it is

versatile, therefore, can be used in operations where immense power is required. However, the

basic principles of an engine remain almost the same since cylinders, and other associated

components are used to run it.

The project deals with an Air Engine controlled by a microcontroller. The primary objective of this

project is to develop an embedded and real-time control system based on the Forth programming

language. Other associated aims are to incorporate user interaction via a keypad and LCD screen

which make significant use of the timing interrupt system capabilities for the inputs and outputs

available. Also implementing a form of control for cylinder firing sequences, designing the wiring

diagram, improving the safety feature, implementing set input of Revolution Per Minute (RPM) via

keypad and maintain the rotational speed was undertaken.

The project is now complete and fully operational with fully functioning hardware configurations and

programming language. Additionally, the programming code has been modified and recreated using

simplified code words which make it easier to understand. As well, extensive documentation is

provided to help for the future development of this project.


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Contents Dedication ............................................................................................................................................... 1

Acknowledgement .................................................................................................................................. 1

Declaration .............................................................................................................................................. 2

Abstract ................................................................................................................................................... 3

List of Figures .......................................................................................................................................... 7

List of Tables ........................................................................................................................................... 8

Term and Abbreviation ........................................................................................................................... 9

Chapter 1 Introduction ...................................................................................................................... 10

Chapter 1.1 Project Objectives ..................................................................................................... 11

Chapter1.1.1 Main Objective for Understanding operation of the Air Engine .......................... 11

Chapter1.1.2 Objectives for Software Implementation ........................................................... 11

Chapter1.1.3 Objectives for Hardware Implementation .......................................................... 11

Chapter1.1.4 Objectives for Safety Features ............................................................................ 11

Chapter 1.2 Project Outline .......................................................................................................... 12

Chapter 2 Background Information ............................................................................................... 13

Chapter 2.1 Overview of Air Engine .............................................................................................. 13

Chapter 2.2 Technical Information ............................................................................................... 14

Chapter 2.2.1 Hardware Setup .................................................................................................. 14

Chapter 2.2.3 I/O Stack board ................................................................................................... 15

Chapter 2.2.3.1 NMIL-0021B Board .......................................................................................... 15

Chapter 2.2.3.2 NMIS-7003 Digital I/O OPTO Board ................................................................. 16

Chapter 2.2.3.3 NMIS-7070 LCD and Keypad Interface Board .................................................. 16

Chapter 2.2.4 Solenoid Valve ..................................................................................................... 17

Chapter 2.2.5 Pneumatic Cylinder ............................................................................................. 17

Chapter 2.3.4 Air filter regulator ............................................................................................... 18

Chapter 2.3.4 Optical Sensor encoder .......................................................................................... 19

Chapter 2.4 Software Development ............................................................................................. 19

Chapter 3 Technical Approach ....................................................................................................... 20

Chapter 3.1 Understanding operation of the Air Engine .............................................................. 20

Chapter 3.2 Project Implementation ............................................................................................ 21

Chapter 3.2.1 Hardware Interface ............................................................................................. 21

Chapter 3.2.2 Software Implementation .................................................................................. 24

Chapter 3.3 Wiring Diagram ......................................................................................................... 25


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Chapter 3.3.1 Previous Wiring Diagram ........................................................................................ 25

Chapter 4 Analysis of Results ............................................................................................................. 26

Chapter 4.1 Result for Auto mode .................................................................................................... 26

Chapter 4.1.1 Auto Mode Flow Chart ........................................................................................ 26

Chapter 4.1.2 Auto Mode Firing and Timing Sequence ............................................................. 27

Chapter 4.1.3 Auto Mode Angle and Rotation .......................................................................... 28

Chapter 4.2 Result for Manual Mode ............................................................................................... 29

Chapter 4.2.1 Manual mode flow chart ..................................................................................... 29

Chapter 4.3 Differences between Auto and Manual Mode.............................................................. 30

Chapter 4.4 Speed Control ................................................................................................................ 31

Chapter 4.5 Updated Wiring diagram ............................................................................................... 31

Chapter 4.5.1 New Wiring Diagram .............................................................................................. 31

Chapter 4.5.2 Optical Sensor Interface Board .............................................................................. 33

Chapter 4.6 Updated Programming Code .................................................................................... 34

Chapter 4.6.1 Add key mapping byte table code .......................................................................... 34

Chapter 4.6.2 Set firing point for clockwise and anticlockwise rotation ...................................... 34

Chapter 4.6.3 The automatic firing cylinder routine .................................................................... 34

Chapter 5 Major Problem Encountered and Solutions ......................................................................... 35

Chapter 5.1 Grounding Issues ........................................................................................................... 35

Chapter 5.2 Mismatching Programming code .................................................................................. 35

Chapter 5.3 Code update .................................................................................................................. 35

Chapter 5.4 Several Components Faulty/Broken ............................................................................. 35

Chapter 5.5 Communication error .................................................................................................... 35

Chapter 6 Future Work ...................................................................................................................... 36

Chapter 6.1 Program Summary ........................................................................................................ 36

Chapter 6.2 LCD implementation ..................................................................................................... 36

Chapter 6.3 Wireless Keyboard ........................................................................................................ 36

Chapter 6.4 Additional Programming ............................................................................................... 36

Chapter 6.5 Human Machine Interaction (HMI) control .................................................................. 36

Chapter 6.6 Safety aspect ................................................................................................................. 36

Chapter 7 Conclusion ..................................................................................................................... 37

Chapter 8 Bibliography ......................................................................................................................... 38

Chapter 9 Appendices ........................................................................................................................ 41

Appendix 9 A: Microcontroller M68HC11 Based Embedded System Hardware .............................. 41


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Appendix 9 A.1 NMIS-0021B ......................................................................................................... 41

Appendix 9 A.2 NMIS 7003 ........................................................................................................... 43

Appendix 9 A.3 NMIS-7070 ........................................................................................................... 44

Appendix 9 B: Forth Air Engine Programming Code ............................................................................. 44

Appendix 9 B.1 User-code text file (user code.f) .............................................................................. 44

Appendix 9 B.2 Air engine text file (air engine.f) .............................................................................. 45

Appendix 9 B.2.1 Defines Constants and Variables Code ......................................................... 46

Appendix 9 B.2.2 Set Constant and Variables ........................................................................... 47

Appendix 9 B.2.3 Set Toggle Switch Code ................................................................................. 48

Appendix 9 B.2.4 Set Push Button Code ................................................................................... 48

Appendix 9 B.2.5 Creates Easy Words to Store Values into Address Locations ....................... 48

Appendix 9 B.2.6 Heartbeat Task .............................................................................................. 48

Appendix 9 B.2.7 Coding for Buzzer ........................................................................................... 48

Appendix 9 B.2.8 Create code for LEDs flashing ....................................................................... 49

Appendix 9 B.2.9 LCD Display Code .......................................................................................... 49

Appendix 9 B.2.10 Keypad Setup ............................................................................................... 50

Appendix 9 B.2.11 Manual Mode Code .................................................................................... 50

Appendix 9 B.2.12 Set Cylinder Mask and Offset ..................................................................... 51

Appendix 9 B.2.13 Set Firing Point for Clockwise and Anticlockwise Rotation ........................ 51

Appendix 9 B.2.14 Speed Calculator Command and Task ........................................................ 51

Appendix 9 B.2.15 Automatic Firing Cylinder Routine for Maintaining Speed ......................... 51

Appendix 9 B.2.16 Automatic Mode Code ................................................................................ 52

Appendix 9 B.2.17 Creates the Auto Mode Task .......................................................................... 53

Appendix 9 B.2.18 Automatic Start-Up and Testing words .......................................................... 53

Appendix 9 B.3 Position Interrupt Text File (Positioninterupt.f) ...................................................... 54

Appendix 9 B.3.1 Set Variables for position interrupts................................................................. 54

Appendix 9 B.3.2 Creates Interrupts Task ..................................................................................... 55

Appendix 9 C: Air Engine Hardware ...................................................................................................... 55

Appendix 9 C.1 Solenoid Valve ......................................................................................................... 55

Appendix 9 C.2 Pneumatic Cylinder Specification ............................................................................ 57

Appendix 9 C.3 Air Filter Regulation Specification ........................................................................... 58

Appendix 9 C.4 Optical Sensor .......................................................................................................... 58

Appendix 9 D: ROM Updating Process ............................................................................................. 59


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List of Figures Figure 1: Air Engine as the whole system ............................................................................................. 13

Figure 2 Air Engine (Top View) .............................................................................................................. 13

Figure 3 Air Engine (Side View) ............................................................................................................. 13

Figure 4 Air Engine (Front Panel) .......................................................................................................... 14

Figure 5 Air Engine (Back Panel) ........................................................................................................... 14

Figure 6 NMIL-0021B Board .................................................................................................................. 15

Figure 7 NMIS-7003 Digital I/O Board ................................................................................................... 16

Figure 8 NMIS-7070 LCD and Keypad Interface Board ......................................................................... 16

Figure 9 3/2 valve symbol [32] .............................................................................................................. 17

Figure 10 Single Acting Pneumatic Cylinder ......................................................................................... 18

Figure 11 View of Air Filter Regulator ................................................................................................... 18

Figure 12 Optical Sensors OPB815W [36] ............................................................................................. 19

Figure 13 Hardware Implementation Overview ................................................................................... 20

Figure 14 Flow chart of the desired response ...................................................................................... 24

Figure 15 Previous Wiring Diagram for Relay Board and Solenoid Valve ............................................. 25

Figure 16 Auto Mode State Pattern ...................................................................................................... 26

Figure 17 Running on Auto Mode ......................................................................................................... 27

Figure 18 Rotary Encoder Direction ...................................................................................................... 27

Figure 19 Manual Mode State Pattern ................................................................................................. 29

Figure 20 Running on Manual Mode .................................................................................................... 30

Figure 21 Example of Changing Speed Control ..................................................................................... 31

Figure 22 New Wiring Diagram for a) Relay Board and b) Solenoid Valve ........................................... 32

Figure 23 Optical Sensor Interface Board ............................................................................................. 33

Figure 24 Microcontroller M68HC11 Block Diagrams [26] ................................................................... 41

Figure 25 NMIS-0021B Unit Layouts [26] .............................................................................................. 42

Figure 26 NMIS-7003 Unit Layouts [27] ................................................................................................ 43

Figure 27 NMIS-7070 Unit Layouts [28] ................................................................................................ 44

Figure 28 SMC Solenoid Valves [15] ..................................................................................................... 55

Figure 29 SMC Clamp Pneumatic Cylinder [16] .................................................................................... 57

Figure 30 Optical Sensors OPB815W [36] ............................................................................................. 58

Figure 31 Manufacture Selection List Window ..................................................................................... 60

Figure 32 Program Status Window ....................................................................................................... 60

Figure 33 File Format Window .............................................................................................................. 61

Figure 34 Editor Window ...................................................................................................................... 61

Figure 35 Auto Window ........................................................................................................................ 62


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List of Tables Table 1 Differences between air and car engine. ................................................................................. 10

Table 2 Inputs and Outputs Terminal ................................................................................................... 21

Table 3 NMIL-0021B Port Mapping ....................................................................................................... 21

Table 4 NMIS-7070 LCD and Keypad Interface Board Port Mapping.................................................... 21

Table 5 NMIS-7003 Digital Input and Output OPTO Card 1 Port Mapping ........................................... 22

Table 6 NMIS-7003 Digital Input and Output OPTO Card 2 Port Mapping ........................................... 23

Table 7 Clockwise Firing Sequences ...................................................................................................... 28

Table 8 Anticlockwise Cylinder Firing Sequences ................................................................................. 28

Table 9 Difference between Auto and Manual Mode .......................................................................... 30

Table 10 Solenoid Valve Specification [15] ........................................................................................... 56

Table 11 Pneumatic Cylinder Specification [16] ................................................................................... 57

Table 12 Air Filter Regulation Specification [18] ................................................................................... 58

Table 13 Optical Sensor Specification [36] ........................................................................................... 59


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Term and Abbreviation ADDD - Add 16-Bit to D

COM - Communication Port

EEPROM - Electrically Erasable Read-Only Memory

EPROM - Erasable Read-Only Memory

GND - Ground

I/O - Input/output

ICE - Instrumentation and Control Engineering

ICSE - Industrial Computer System Engineering

IRQ - Interrupt Request

JMP - Jump

LCD - Liquid Crystal Display

LDAA - Load Accumulator A

LDD - Load Double Accumulator D

LED - Light Emitting Diode

MCU - Microcontroller Unit

NPN - Negative-Positive-Negative Bipolar Transistor

OS - Optical Sensor

PA(x) - Port A pin (x)

R/W - Read/Write

RAM - Random Access Memory

RMS - Root Mean Square

ROM - Read-Only Memory

RPM - Revolution Per Minute

RTI - Return from Interrupt

RTII - Real-Time Interrupt

RTS - Return from Subroutine

RxD - Receive Signal

STAA - Store Accumulator A

STD - Store Accumulator D

SV - Solenoid Valve

SW - Switch

TB - Terminal Block

TCTL - Timer Control Register

TDC - Top Dead Centre

TFLG 1 - Main Timer Interrupt Flag Register 1

TFLG 2 - Miscellaneous Timer Flag Register 2

TIC - Timer Input Capture Register

TMSK 1 - Main Timer Interrupt Mask Register 1

TMSK 2 - Miscellaneous Timer Interrupt Mask Register 2

TxD - Transmit Signal

VCC - Positive Supply Voltage

VDC - Voltage Direct Current


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Chapter 1 Introduction This project is a teaching and an education tool project for hands-on experience with industrial

equipment and communication system, the most important thing about this project is to keep the

previous work has been done and update the system operations. Hence, the improvement and

maintenance duties to the functionality of the air engine are the primary aspects of the on-going

thesis project.

In the 19th century, the first air engine was produced and was given different names such as heat,

hot air, caloric or compressed air [1]. This early design always had a great potential for high

efficiency and low emission power generation. However, the major obstacle to its practical use in

the past was the lack of sufficiently heat resistant materials since not many materials were known to

the public. This obstacle has now eliminated due to the higher strength of modern material and

alloys. The basic design of an air engine is such that it enables the engine to run purely on

compressed air to expand and extend a pneumatic actuator which turns the engine. [1]

Initially, the air engine used the SwiftX development and programming environment for

implementing the programming code and controlling the system by using a 68HC11 microcontroller.

SwiftX is based on the Forth programming language; it provides a fast, and powerful tool for the

development of software for embedded and real-time control system. As a multitasking software,

operating system SwiftX provides the service to multiple programs operating without any fixed

timing relationship (i.e. asynchronously). [4]

The main idea and concepts of the air engine are similar to a car engine, say one with four cylinders,

where the firing sequence of the cylinder and rotation of the shaft is very similar. However, some of

the differences between an air engine and car engine are the arrangement and actions of the

cylinders, fuel type, and their components. The air engine runs by using compressed air rather than

driving the pneumatic cylinder extension, compressed air uses the expansion of compressed air, in a

similar manner to the expansion of steam in a steam engine. The Table 1 below shows some of the

significant differences between the two engine.

Table 1 Differences between air and car engine.

Components Air engine Car engine

Fuel Compressed Air Petroleum products

Ignition None Needed, spark plug

This project was not started from the scratch but had not been operating for many years since

October 2010, lastly operated by third years’ students for the ENG306 in a class project. Although

they did the project, it was not well documented. The latest programming code was provided but

during the testing and investigation of the software and hardware, it was found that many of the

components were changed and not working because the equipment has been sitting in the store

room for years. For further investigation, underlying the issue and proceed with troubleshooting and

reorganizing the hardware and programming code to end up this project is on-going project hence

this was one of the goals. [8]


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Chapter 1.1 Project Objectives The aim of this project is to upgrade the communication and control of the air engine. This Section

consists of four categories which relate to the primary aims of the project. The goals are listed

below:

1. Understanding operation of the Air Engine

2. Software Implementation

3. Hardware Implementation

4. Safety Features

Chapter1.1.1 Main Objective for Understanding operation of the Air Engine

The primary phase was to get the air engine operating and functional. The key focus of this phase

was to ensure this project can operate reliably via the 68HC11 microcontroller and develop the

embedded and real- time control system based on the Forth programming language. The software

has been upgrading to its latest version, from “SwiftX Pro 68HC11 3.8.8 (05 February 2015)” to

“SwiftX/68HC11 V3.8.8 ICSE Lab NMIY-0020 (31 July 2015)”. The programming code from the

previous students can be re-downloaded, and the system can be investigated and tested for any

faulty components or mismatched communication between programming code and hardware. Once

completed, it was possible to underline all the parts that needed replacement followed by

troubleshooting of the wiring and connection for interface electronic, and for mismatched

communication of the programming code can be upgraded and reorganized based on the system.

Chapter1.1.2 Objectives for Software Implementation

The second objective consists of developing and implementing the programming code to

communicate with the air engine. The investigation includes, how the Forth programming language

communicates with the interface electronics and instruments, what changes have to be done for the

program code and how it is working. The next step is to implement user interaction via a keypad and

LCD screen, investigating the significant use of the timing interrupt system capabilities for the input

and output available, implementing the set input of RPM via keypad and maintaining the rotational

speed.

Chapter1.1.3 Objectives for Hardware Implementation

As mention previously, this project was not fully documented which includes missing wiring and

connection diagrams. For the third phase, the purpose is to investigate with rechecking, redesigning

the wiring, block, and process flow diagram for the overall system. Once finished, it will be easier to

troubleshoot and investigate the wiring and any connections problem in the system.

Chapter1.1.4 Objectives for Safety Features

Once the overall system has been successfully implemented and commissioned, the next objective is

to proceed with the design of safety features for the air engine since there is are moving

components which are hazardous for the users and any future works.


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Chapter 1.2 Project Outline For the project, the outline will start with an overview of the system design, hardware, and software

is provided to the reader in chapter 2 which relates to the background information and

understanding for the following sections. Chapter 3 will describe the major work undertaken during

the investigation and tested for the project. Also, the description is more related to the objective

phase that has been mention previously. Chapter 4 describes the results acquired during the testing

phase. Chapter 5, outlines the major problems encountered and the issues during the project which

led to not all of the objectives step being satisfied and completed. In chapter 6, there will be a

description of the recommendation for future work and the last chapter will be the conclusion of the

project which will summarize the satisfied and unsatisfied of the project.


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Chapter 2 Background Information This chapter contains all necessary background information on the air engine and previous related

work; it will cover an overview of the air engine, and its technical information.

Chapter 2.1 Overview of Air Engine The Murdoch Air Engine is one of the industrial computer system projects for students at Murdoch

University. As shown in Figure 1,2 and 3, this project consists of white chassis made out of box

tubing. Attached to this is a metal flywheel of considerable weight which is mounted to a shaft, held

to the chassis by a series of bearings. The pneumatic cylinders are also attached to the flywheel

crankcase in a similar manner as a car engine design; enabling a linear motion converted into

rotational motion. The solenoid valve transforms an electrical signal into a physical movement of the

valve which allows air to be either vented to atmosphere or pumped through to the cylinders.

Furthermore, this project also consists of a flywheel driven by four pneumatic cylinders. The

cylinders attached in pairs on each side of the wheel are set on two bosses 90 degrees to each other

on the wheel and is attached to the shaft encoder.

Figure 1: Air Engine as the whole system

Figure 2 Air Engine (Top View)

Figure 3 Air Engine (Side View)


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Figure 3 illustrates the shaft-encoder disk with 64 holes equally spaced around the circumference of

the disk and one larger hole located in between of the disk. The two optical sensors attach to the

disk are used to initiate a counter that will activate the movement of the solenoid valve whether

extend or retract when the sensor detects the particular set point value of small holes, and will reset

the counter when it senses a big hole.

Chapter 2.2 Technical Information This Section will describe the fundamental knowledge of the hardware and software that is provided

for this project.

Chapter 2.2.1 Hardware Setup

The hardware available in this project is on the front panel as shown in Figure 4 which consists of:

RS232 connector, LCD, keypad, and buzzer,

Seven switches (includes a stop push button, two toggle, and six push-button switches),

Ten LEDs (includes LEDs for a heartbeat, direction, cylinder one to four and output one to

four).

Figure 5 illustrates the back panel consisting of:

Input and output stack board,

Optical sensor interface board,

Relay and solenoid valve interface board.

Figure 4 Air Engine (Front Panel)

Figure 5 Air Engine (Back Panel)


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Chapter 2.2.3 I/O Stack board

The input and output stack board consist of three different boards namely:

NMIL-0021B for M68HC11 microcontroller board [26]

NMIS-7003 for digital input and output boards [27]

NMIS-7070 for LCD and Keypad interface board [28]

These boards use the 34 pin JEDSTACK connector as interface signals to the board including the five-

volt supply, ground, control lines, address lines and data lines. The addressing of the circuitry on the

board is identified by two octal comparators that decode the sixteen address lines and one control

line. The current address location can be arranged to a high or low condition by the arrangement of

addressing jumpers. [29]

Chapter 2.2.3.1 NMIL-0021B Board

Figure 6 shows the main components on this board are the M68HC11 micro-controller, EEPROM,

RAM, five parallel ports (includes Ports A, B, C, D, and E), RS232 and reset ports connector. The

micro-controller M68HC11 is the main processor, together with an ancillary component that

provides a very powerful embedded controller and has many derivatives with different memories

slots and output configurations. The microcontroller will allow the rapid program development

through pre-prepared connections to typical components and easy to download and modify the

programming code. The programming code can be developed by using SwiftX or any Motorola

development programming software and then directly download into the mounted ROM. The

connection is directly from the computer serial port to the development board and the various

components through the RS232. [29]

Figure 6 NMIL-0021B Board

This controller board was primarily chosen because it was capable of driving the air engine with low

power consumption and high-performance operations at bus frequencies up to 4MHz. Some of the

features of the M68HC11 controller that includes:

eight bit analog to digital converter,

two of eight on the sixteen-bit accumulator,

two of sixteen index register,

powerful bit manipulation instructions,

six powerful addressing modes,

power equal to saving STOP and WAIT modes,

memory mapped input and output,

eight by eight multiplication,

sixteen by sixteen integer and fractional dividers.


16

The isolation is provided for this board through the optical isolation unit. This board also provides an

external memory expansion to move the terminal input buffer and dictionary into the external

memory, if the RAM is installed into the address 0100 to 1FFFF of the memory bit. The purpose of

the isolation barrier is to have a safe operating unit. [29]

Chapter 2.2.3.2 NMIS-7003 Digital I/O OPTO Board

Figure 7 NMIS-7003 Digital I/O Board

Figure 7 shows the two boards that provide the extra input and output capacity that is required to

run the air engine setup. There are eight-bit separate inputs and one output on the board for the

LEDs and switches connections. The isolation for this board is provided through the optical isolation

unit; the OPTO-isolation will invert the condition for any outputs activated. Therefore, to activate a

device, the output must be in its low condition and to turn a device OFF, the output must be in high

condition.

Chapter 2.2.3.3 NMIS-7070 LCD and Keypad Interface Board

Figure 8 NMIS-7070 LCD and Keypad Interface Board

The interface boards shown in Figure 8 has two distinctly different type of devices, one is an LCD, it

can have up to four display controller chips, and the other one is the keypad controller. The

programming for these two devices is totally different; they operate completely independently, and

one function can be used without the other. It uses sixteen consecutive addresses, if a display with a

single display controller chip is used, only four address location will be active, two for keypad

controller and the other two for the LCD. [28]

The keypad controller interface is dependent on the particular code generated when a specific

column or row position is activated by a key pressed. The keypad controller will scan the matrix

constantly, and when it detects a key pressed, it will drive the data available to be high. After the key

is released, the data remain latched, and the strobe disappears. For the five data bits A, B, C, D, and

E, are read as data bus bit D0 to D04 and the data available strobe will be read as a bit D6. [28]


17

This boards also provide a connector with an interface to an intelligent alpha-numeric LCD and

twenty key for the keypad controller. The connectors can be easily associated with a ribbon cable,

power, and ground to the keypad and display. [28]

Chapter 2.2.4 Solenoid Valve

There are four solenoid valves used in this project to operate and control in and out air flow for the

firing of the cylinders. The valves used are ‘3/2 way’ direct acting solenoid valve with two positions

switching and three ports to open or close the inlet or exhaust ports of the solenoid valve. The

original condition of this valve is usually open which means that the initial position for inlet port P is

open to outlet port A with exhaust port R closed. Once energized, the solenoid valve brings the inlet

port P to a closure and outlet port A is enabled to vent through exhaust port R. [32]

Figure 9 3/2 valve symbol [32]

Figure 9 illustrates a 3/2 valve symbol, however, in some instances, the normally open solenoid valve

configuration would use port R as the inlet port and port A as outlet port thus making port P as the

exhaust port. This arrangement offers a reduction in cost and a common way of obtaining the

normally open function. The advantages of this solenoid valve are its low cost, compactness; it does

not require any pressure differential to operate and with a small coil offering reduces power

consumption.

This solenoid valve is also suitable for most general purpose media application and can be found in

either stainless steel, brass and plastic bodies variants. For the specification of the solenoid valve

refer to the Appendix 9 C.1. [32]

Chapter 2.2.5 Pneumatic Cylinder

This project used four single-acting pneumatic cylinders to operate and move the flywheel. This

pneumatic cylinder only has one compressed air inlet flow connection as shown in Figure 10. The

incoming compressed air will move the piston in one direction, and the force within the cylinders

builds up in this direction. If there has no entering of compressed air, the spring pushes the piston

back to its original position. These cylinders have an exhaust hole such that the volume behind the

piston is kept at atmospheric pressure. [30]

The advantages of this pneumatic cylinder are easy actuation via a 3/2-way solenoid valve, defined

the position in the event of a power failure and reduced air consumption. As for the disadvantages,

this cylinder has the spring force to reduces strength, no constant force, the force is simply built in

one direction, and the spring dependent has stroke length limiting the maximum stroke length. For

the specification of the pneumatic cylinder refer to the Appendix 9 C.3. [30]


18

Inlet FlowExhaust

Figure 10 Single Acting Pneumatic Cylinder

Chapter 2.3.4 Air filter regulator

Air filter regulator is used to reduce the incoming compressed air through for the efficient operation

of pneumatic equipment. As shown in Figure 11, an air filter will clean the entering compressed air

and traps any kinds of material, such as dirt, rust, and dust. [33] It also separates water and oil

entrained in the compressed air. Using the air filter, it ensures:

that less damage is made to the equipment,

that it reduces the production losses, and

the removal of the contaminants from the pneumatic system. [33]

Figure 11 View of Air Filter Regulator


19

Chapter 2.3.4 Optical Sensor encoder

This project used two optical sensor encoders with two different functions. One is used to detect the

revolution of the flywheel, allowing the calculations of the RPM to be displayed on the LCD.

Secondly, it is used to detect the position of the wheel so that the appropriate cylinders could be

activated. The encoder on the air engine consists of the metal disk with 64 holes cut on the inner

channel of the encoder with one big hole left on the outer channel. The inner channel was used to

determine the relative position of the encoder, but the outer channel finds top dead center (TDC).

The TDC mark allows the revolution of the air engine to be counted accurately and used as a

reference point to determine the optimum firing timing and duration of the speed.

Figure 12 Optical Sensors OPB815W [36]

Figure 12 shows the optical sensor which consists of an infrared emitting diode and an NPN silicon

phototransistor mounted in the low-cost plastic housing on opposite sides. The phototransistor

switching takes place whenever an opaque object passes through the slot. For further information,

refer to Appendix 9 C.4. [20]

Chapter 2.4 Software Development This project is programmed by using SwiftX a programming environment is in for the Forth

programming language. This language was developed in the 1970s by Charles H. Moore; Forth is a

high- level language that provides interactive development and allows language extension. [39]

In the SwiftX folder, there are multiple files which include the app file, user code text file, air engine

text file and position interrupt text file as shown in Appendix 9 B.3. The user code text file is the

important code for this system; it is the main program to start the background of the programming

code that has been created. The app file is programmed into the ROM, a time-consuming process

requiring ultraviolet erasing to wipe the previous program.

The user code text file can be quickly updated via downloading and debugging the program code

from software in the personal computer (PC) terminal to RAM. The testing, debugging and

development of the project programming code is completed in the user code text file. The

programming code can be transferred between the languages. Therefore, this project will focus on

the code design and structure.


20

Chapter 3 Technical Approach

Chapter 3.1 Understanding operation of the Air Engine The hardware is a significant as the software. The overview as provided in Figure 13 below:

Reset Push Button

Interface Electronics

Terminal Block 6

LEDS for Output 1 to 4

Switches ON/OFF & Direction

Push Button 1 to 4

Buzzer, LEDS for Heartbeat and Direction

Relay Board

Keypad & LCD

Switf-X Development & Program Enviroment

Switf-X Development & Program Enviroment

NMIS-7003 Digital I/O

OPTO Board 2

NMIL-0021BM68HC11

Board

NMIS-7070 LCD & Keypad

Interface Board

Optical Sensor Shaft Encoder Disk

LEDS for Cylinder 1 to 4

Flywheel

Solenoid Valve 1 to 4 Cylinder 1 to 4

RS2

32

NMIS-7003 Digital I/O

OPTO Board 1

Terminal Block 5

Terminal Block 4

Terminal Block 3

Terminal Block 2

Terminal Block 1

Add

ress

& D

ata

Bus

Figure 13 Hardware Implementation Overview

From Figure 13, it can be observed:

The program developed in Swift X can be downloaded from the PC to the M68HC11

microcontroller via a serial connector RS232 cable. The main board consists of an NMIL-

0021B, NMIS 7003 Digital I/O 1 and 2, and the LCD and keyboard interface boards. Each of

these different components conducts a separate operation. They are connected to each

other via a vertical stacking connector (VSC).

NMIL-0021B is the control board. The optical sensor reads the encoder disk value and the

readings are fed to a set of electronics and finally submitting to the microcontroller. Also, a

reset switch is attached to the controller to allow the program to be reset when it crashed

during the development phase.

NMIS 7003 Board 1 – it reads the status of the switches including the direction switch and

the LEDs. It also controls the LED for the output.

NMIS 7003 Board 2 – the latter is concerned with the operation of the buzzer, LEDs for

Heartbeat and direction. As well, it controls the solenoid valves via the relay board. That

results in the moving of the cylinders hence the moving of the wheel. Indirectly, this board is

connected to the controller since the controller reads the rotation of the wheel.


21

LCD & Keypad Interface Board – it is concerned with displaying the desired process

parameters and keypad controller.

The terminals are the inputs and outputs that feed into the different boards. Table 2

illustrates the various inputs and outputs on the board:

Table 2 Inputs and Outputs Terminal

Boards Inputs Outputs

NMIS 7003 Board 1 Terminal Block 3, and 4 Terminal Block 5, and 6

NMIS 7003 Board 2 No Terminal Block 1, and 2

These boards were connected via a 32 pin vertical stacking connector (VSC) and have different

addresses lines. Each of the four boards has a unique address. Port mapping is done to know the

various addresses that the components have. As well, the various components such as all the LEDs,

buzzer, switches and the inputs for the relay board have different bit addresses. Further information,

can be found in the hardware interface Section in Section 3.2.1.

Chapter 3.2 Project Implementation This Section will demonstrate the project implementation, the different attributes make for the

whole process. The two most important are the hardware interface and software implementation.

Chapter 3.2.1 Hardware Interface

For the hardware interface was complete by re-checking the port mapping for each board. The

approach taken was trial and error to investigate which port was connected to where by setting

individual bits high and low for the port addressed. From a very early stage, it was possible to detect

that the board was wired in a fashion that was since setting the bit high resulted in the output being

the switched off whereas setting the bit low resulting in it being set high. Although the major part of

the code was just easier to continue with the traditional convention that had been learned and

instead utilize the insert command. This trial and error method did, however, lead to the association

of bits and memory locations to control the following inputs and outputs as shown in Table 3, 4, 5,

and 6.

Table 3 NMIL-0021B Port Mapping

Bit Hexadecimal Address Port Address Specification

1 1 Port A1 Outer Ring Encoder

2 2 Port A2 Inner Ring Encoder

Table 4 NMIS-7070 LCD and Keypad Interface Board Port Mapping

Port Address Specification

$8440 Liquid Crystal Display (LCD)

$8441 Keypad Controller


22

Table 5 NMIS-7003 Digital Input and Output OPTO Card 1 Port Mapping

BIT Hexadecimal Address Port Address Specification

1 01 $8400 (Inputs) Push Button 1

2 02 Push Button 2

3 04 Push Button 3

4 08 Push Button 4

5 10 Direction (Toggle Switch)

6 20 ON/OFF (Toggle Switch)

7 40 No

8 80 No

9 01 $8401 (Outputs) LED Cylinder 1

10 02 LED Cylinder 2



13 10 LED Output 4

14 20 LED Output 3

15 40 LED Output 2

16 80 LED Output 1


23

Table 6 NMIS-7003 Digital Input and Output OPTO Card 2 Port Mapping

BIT Hexadecimal Address Port Address Specification

1 01 $8420 (Inputs) No

2 02

3 04

4 08

5 10

6 20

7 40

8 80

9 01 $8421 (Outputs) Relay (Pin 0)

10 02 Relay (Pin 0)

11 04 Relay (Pin 0)

12 08 Relay (Pin 0)

13 10 LED Heartbeat

14 20 LED Clockwise

15 40 LED Buzzer

16 80 No


24

Chapter 3.2.2 Software Implementation

A flow chart is made before any programming is started. The flow chart is presented in Figure 14

below:

Figure 14 Flow chart of the desired response

When the program is downloaded and debugged, the first thing that the controller would check is

whether the emergency button is pushed. If so, the program will jump to the first state. If not,

progress would be made by jumping to another state which is “checking whether the engine is

initialized”; otherwise, the program will go back to the original state.

Imagine the engine is initialized, all the cylinders and LEDs would be off, however, if the engine is not

on, the result would be the program returning to the beginning state. Suppose the engine is on, and

all the LEDs and cylinders are off, the program will wait for the user to enter the desired mode

shown as the “Selected mode in Figure 14.” The choices offered are between “manual” or

“automatic”. If all the states explained above are false, the program will go to the initial state.

If the engine is not initialized, the program verifies whether the emergency button is pressed and

then goes to the first state. Whenever the emergency button is pressed, all the operations will stop,

and the program will render to the first state. When the engine is not running, the program thinks

that the emergency button is pressed, breaks the operation and goes back to the beginning.


25

Chapter 3.3 Wiring Diagram As mention previously, this project was not complete documented and has missed the wiring

diagram, after re-designed the previous wiring diagram can be described as shown in Figure 15

below. The design of this diagram was not maintained from former student and the resulted of

wiring the 12 Volt relay and solenoid valve with the polarity inverted into 12 Volt power supply and

also the wiring connection of ground for 5 Volt and 12 Volt were connected in series.

This connection cause of destroyed all four transistors, the consequence of this issue is consumed of

the feedback current from solenoid valve is more than the maximum current of 0.8 ampere (A) for

the transistor. To solve this problem, new wiring diagram has been designed as shown in Figure 22.

Chapter 3.3.1 Previous Wiring Diagram

SV 1

RelayContact 1

Power Supply 112 VDC

D1

T1

R1

Pin 0

D2

T2

R2

Pin 1

D3

T3

R3

Pin 2

D4

T4

R4

Pin 3

Relay 1 Relay 2 Relay 3 Relay 4

Power Supply 15 VDC

Receive signal From TB1NMIS-7003 Digital I/O OPTO Board 2

Pin 0

Pin 1

Pin 2

Pin 3

Stop Push Button

Note:1) Resistor (R1,R2,R3.R4) = 1.5 kΩ 2) Transistor (T1,T2,T3,T4) = NPN Transistor (BC337)3) Diode (D1,D2,D3,D4) = IN4004 4) Solenoid Valve (SV1,SV2,SV3,SV4)

SV 2

RelayContact 2

SV 3

RelayContact 3

SV 4

RelayContact 4

Figure 15 Previous Wiring Diagram for Relay Board and Solenoid Valve


26

Chapter 4 Analysis of Results This section will brief about the results obtained and will analyze whether the latter is what was

expected from the system. It should be noted that there are two modes of the experiment.

Chapter 4.1 Result for Auto mode Result for auto mode is consists of:

Auto mode flows chart

Auto mode firing and timing sequence

Auto mode angle and rotation

Chapter 4.1.1 Auto Mode Flow Chart

Figure 16 illustrates the flow chart state pattern for auto mode, this is continuing chart as described

and shown in Figure 14 if the auto mode has been selected.

1

Is Auto ModeSelected?

SuspendManual Mode

Task

Stop Firing Cylinders & Turn all

LEDs OFF

Is Toggle Switch ON?

Is Direction Switch ON?

Start ANTI-CLOCKWISEFiring Cylinder & LEDs Sequence, Start Speed Task

Start CLOCKWISEFiring Cylinder & LEDs Sequence,Start Speed Task

Yes

No

Yes

Yes

No

No

Is STOPEngine?

Yes

No

Figure 16 Auto Mode State Pattern

The “1” represents if auto mode is selected. As auto is nominated, the engine is ready to start. When

the engine starts, the program checks whether the toggle switch is reading a high. When the toggle

switch is turned on, the program reads in which the direction switch is reading. If yes, the wheel

from the side view as shown in Figure 3 will rotate clockwise and undergoes a sequence of the LEDs

lighting similar to the firing cylinder rotation but if no then the wheel turns anticlockwise, and the

LED sequence follows the pattern.


27

Assume that the engine is giving a low then all the cylinders and LEDs cease their operation. Another

scenario is if the engine starts but the toggle switch is not on, the result is the same as described

above. Now, say when the auto mode is selected, and after selection nothing is fed into the

program, the resulting state would be the program jumping to the stage where it checks again if any

mode is selected.

When the auto mode is selected, as a precaution the manual mode is suspended. This step is taken

to avoid confusion between the two modes tasks; that may occur during the simulation given that

this is a learning material for the beginners.

The auto mode is different compared to the manual mode. The former is a firing and timing

sequence as descript in Section 4.1.2. When auto mode is selected it is displayed on the LCD as

shown in Figure 17, also for clockwise and anticlockwise motion, it is indicated through direction

LED.

Figure 17 Running on Auto Mode

Chapter 4.1.2 Auto Mode Firing and Timing Sequence

Figure 18 Rotary Encoder Direction


28

Figure 18 illustrates the direction of the rotary encoder either clockwise or anticlockwise followed by

the firing sequence as shown in Table 7 and 8. The cylinder is fired over a range of hole counts

between 5 and 20, 21 and 36, 37 and 52, 53 and 4. The difference of the firing sequence for

clockwise and anti-clockwise is in between cylinder 2 and 4; it is because after the optical sensor

detects the big hole, the counter will start to count the position back to zero.

The firing order starts from cylinder 1, 2, 3, 4 for anti-clockwise and cylinder 1,4,3,2 for clockwise.

The duration of the firing time of each cylinder can be changed dynamically in the command

window; this will act to control the speed of the engine. This pattern and sequence of the rotation

are only in auto mode.

Chapter 4.1.3 Auto Mode Angle and Rotation

The auto mode angle and rotation is followed whether clockwise or anticlockwise direction.

Table 7 Clockwise Firing Sequences

Angle, (degree) 0 45 90 135 180 225 270 315

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

For the clockwise firing, assuming at the start of the operation, the arrangement of the cylinders is

(in regards to Figure 18 and Table 7):

Cylinder 1 – will start at an angle of 45 reaching up to 90 degrees during firing,

Cylinder 4 – will be at 135 degrees reaching up to 180 degrees

Cylinder 3 – will be at 225 degrees, attaining up to 270 degrees and

Cylinder 2 – will be at 315 degrees reaching up to 0 degrees.

Table 8 Anticlockwise Cylinder Firing Sequences

Angle, (degree) 0 45 90 135 180 225 270 315

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4


29

For the anticlockwise firing, assuming at the start of the operation, the arrangement of the cylinders

is (in regards to Figure 18 and Table 8):

Cylinder 1 – will start at an angle of 45 reaching up to 90 degrees during firing,

Cylinder 2 – will be at 135 degrees reaching up to 180 degrees

Cylinder 3 – will be at 225 degrees, attaining up to 270 degrees and

Cylinder 4 – will be at 315 degrees reaching up to 0 degrees.

Chapter 4.2 Result for Manual Mode

Chapter 4.2.1 Manual mode flow chart

Figure 19 illustrates the flow chart state pattern for manual mode, this is continuing chart as

described and shown in Figure 14 if the manual mode has been selected.

Figure 19 Manual Mode State Pattern

The “2” asserts the manual mode is selected. This state waits till the user enters all the data such as

push button 3 to do a designated action. At each stage, the program waits till the new condition is

fitted into the system and then it performs the related action.


30

When the manual mode is selected, the program verifies which button (1,2,3 or 4) is pressed and

depending on the user choice, the according cylinders and LED would start. The firing cylinder would

be displayed on the LCD.

If nothing is selected or if the emergency button is pressed, the program will return to the original

state. It is also possible to stop any of the processes via the software by typing the appropriate code.

Similar to the auto mode, if manual mode is selected, the auto mode is suspended hence no

operations under auto will be performed. When the engine is stopped, all the other operations like

firing cylinders and LEDs will stop respectively.

The purpose of manual mode is to run the system manually by pressed the input push button

whether 1, 2, 3 or 4. Once the desired push button is activated, the relative cylinder will fire, and the

LCD will acknowledge and display which cylinder is firing as the example shown in Figure 20 below.

This mode is an entirely difference with auto mode as descript in Section 4.1.1, once it running in

manual mode the firing order is depending on the desired push button activated.

Figure 20 Running on Manual Mode

Chapter 4.3 Differences between Auto and Manual Mode Though it is the same system, the manual, and the auto mode run differently, and some of the

major differences are given in Table 9 below:

Table 9 Difference between Auto and Manual Mode

Differences Auto Manual

Pattern and Sequence Well ordered, follows angle No pattern and sequence

LCD display Only shows cylinder Shows which cylinder is firing

LED sequence Depends on directions Depends on which push button

is active

Speed Controllable Very slow


31

Chapter 4.4 Speed Control It was desired to control the speed, however, due to time constraints, this was not entirely possible.

A simple method was used instead where the duration of a cycle was altered resulting in the change

of speed of the wheel. So if the cycle time is less, then the wheel will rotate faster compared the

cycle time is longer. The speed control can be changing while it running in auto mode and to

changing the cycle time follow as example shown in Figure 21 below:

Figure 21 Example of Changing Speed Control

Variable as illustrated in Figure 21 can be described as:

XYZ is variable to modify the number of offsets,

PERIODON is variable to modify the cycle of time,

DISPLAYP is variable to display the current position of the rotary encoder disk.

Chapter 4.5 Updated Wiring diagram As mentioned before, the wiring diagram was updated since there was less information available

from previous years. To solve the problem has been described in Section 3.3, the wiring connection

of solenoid valve and relay board have to separate by two difference of wiring connection and input

of power supply, for further information for this diagram, refer the description in Section 4.51. Also,

a new wiring diagram for optical sensor interface board has been designed as it was missing from

the previous student, for further information for this diagram, refer the description in Section 4.5.2.

Chapter 4.5.1 New Wiring Diagram

Figure 22 illustrates the relay board used a 12 Volt supply as a specification for the relay and

connected in series with the ground of 5 Volt as an incoming signal from digital I/O is 5 Volt supply.

This connection has no feedback current because the 12 Volt supply is used to trigger the relay when

there is an incoming signal from digital I/O board. Once the signal triggers the relay, then contact

relay will be in a closed circuit and energize the solenoid valve to start firing order and sequence as

follow the mode has been selected.


32


SV 1

Relay Contact 1

SV 2 SV 4SV 3

Relay Contact 2

Relay Contact 3

Relay Contact 4

b)


D1

T1

R1Pin 0

D2

T2

R2Pin 1

D3

T3

R3Pin 2

D4

T4

R4Pin 3

Relay 1 Relay 2 Relay 3 Relay 4

Power Supply 15 VDC

Receive signal From TB1NMIS-7003 Digital I/O OPTO Board 2

Pin 0

Pin 1

Pin 2

Pin 3

a)

Stop Push Button

Note:1) Resistor (R1,R2,R3.R4) = 1.5 kilo ohms2) Transistor (T1,T2,T3,T4) = NPN Transistor (BC337)3) Diode (D1,D2,D3,D4) = IN4004 4) Solenoid Valve (SV1,SV2,SV3,SV4)

Figure 22 New Wiring Diagram for a) Relay Board and b) Solenoid Valve

Item used in Figure 22 are four Diodes (IN4004), four Resistors (1.5 kΩ), four Relays (12 VDC) (Good

sky), two power supply 12 Volt, one power supply 5 Volt, and four NPN transistors (BC337). The relay

pins 0,1,2, and 3 are receiving their signal from the outputs of the NMIS digital I/O board two which

is primarily responsible for the movement of the cylinders. Also to stop the operation in case of an

emergency, there is a push button to break the contact, known as the “Emergency stop push

button.”

The transistors are used to control the amount of current that flows through the other components

hence securing them from an overcurrent situation. As well, the diodes dictate that the current will

flow in only one direction. The resistors are put into place to limit the amount of current flowing

through the circuit. The solenoid valves (SV1-4) are powered by a 12V supply as shown in Figure 22

(b). The Relay from Figure 22(a) acts as a trigger which then make the contact relay from the bottom

circuit to be closed, and the solenoid valves (SV1-4) would be energized hence this will allow the

movement of the cylinders.


33

Chapter 4.5.2 Optical Sensor Interface Board

Figure 23 illustrates another wiring has been designed after go through in detailed the interface

board. This board is used to detect the movement on the wheel.

ORANGELED

C2C1

1 2 76543

GND

VCC

IC:SN74LS14N

14 13 12 11 10 9 8

Power Supply 15 VDC

G1 R1

G2 R2

B2W2

OS1

OS2

R1

R2

R4

R3 REDLED

R5 R6

PA1 PA2

B1W1

Send signal to Port A1 and A2

Note: 1) OS1 and OS2 – Optical Sensor 1 and 22) VCC – Positive Supply Voltage3) GND – Ground 4) IC – Inverter Chip

Figure 23 Optical Sensor Interface Board

This diagram can be described as:

The signal coming from the optical sensor will be converted by an inverter chip to high if the

optical sensor detects the signal and low if undetected.

This board uses two LEDs. The red LED is for position detection, and the orange LED is for

revolution.

A 5 VDC supply powers this board.

There are two optical sensors to detect the position (small hole) and revolution (big hole).

R is the resistor – (R1, R2, R5, R6 = 470Ω), (R3 and R4 = 68-kΩ)

C is for Capacitor – (C1 and C2 = 0.1µF)

Inverter chip (IC), model SN74LS14N [40]

After inverted signal then sending to port A1 (revolution) and port A2 (position).

The IC is a non-inverting Schmitt Trigger. [41] The latter acts as a voltage comparator which has two

different threshold levels. If an input signal is higher than the upper threshold level of the

comparator, a high is fed to the rest of the circuit and vice versa [41]. The advantages are their low

price, no need to have a really neat signal since they can read through noisy signal too [42].


34

The current IC was provided with the board, and the previous work has been conducted using the

same board. Some highlights of the IC are [40]:

Low input voltage, around 5V,

Low current output, about 8mA.

Chapter 4.6 Updated Programming Code The updated programming code was developed in relation the technical approach in Section 3 and

updated wiring diagram in Section 4.5. Some of the update and new code written are:

Add a new key mapping byte table code,

Set firing point for clockwise and anticlockwise rotation,

The automatic firing cylinder routine,

Chapter 4.6.1 Add key mapping byte table code

From previous work, the setup of the keypad controller for this system does not follow the actual

label on the keypad. By creating the new code for byte-table “map key” is to map a code read from

the keypad to the actual label on the keypad. For further information for this code, refer to Appendix

9 B.2.10.

Chapter 4.6.2 Set firing point for clockwise and anticlockwise rotation

This code is created for set firing point for the cylinder to running the system whether in the

anticlockwise or clockwise rotation. The setup for this code is to make it easier to changing the

offset, length of duration and firing point that has been set.

The initial setup of the firing point for the cylinders are fired as follow below:

For anticlockwise, the cylinders will fire at hole number 5 for cylinder 1, 21 for cylinder 2, 37

for cylinder 3 and 53 for cylinder 4.

For clockwise, the cylinders will fire at hole number 5 for cylinder 1, 53 for cylinder 2, 37 for

cylinder 3 and 21 for cylinder 4.

This setup is to run the system with constant speed and similar form in beginning of the system

rotation. To change the configuration, refer the example as shown in Figure 21. For further

information for this code, refer to Appendix 9 B.2.13.

Chapter 4.6.3 The automatic firing cylinder routine

This code is created for the setup an automatic firing cylinder method, once the rotation has been

selected, this code will start the firing sequence routine as has been described in Section 4.1.2. For

further information for this code, refer to Appendix 9 B.15.


35

Chapter 5 Major Problem Encountered and Solutions This Section will describe the significant issues encountered during this project.

Chapter 5.1 Grounding Issues The optical sensor interface board and relay board were built as an interface between the different

I/O devices. The wiring diagram for both boards was not available and provided from reports,

meaning new diagram had to comply. During tracing the individual wires that had been connected to

the boards and the hardware, it was found that the connection of 12 Volt ground for solenoid valve

is connected in series with the relay board 5 Volt ground. This could be the cause of all transistors

blowing.

Chapter 5.2 Mismatching Programming code The code from previous years act differently on the system. Through investigation, it was found that

the programming code for the keypad and the RPM do not work. So new codes had to be developed.

Chapter 5.3 Code update During the review of the previous code, it was found that the code was written in a complicated way

which was hard to understand. Furthermore, it was not commented properly hence creating a tense

environment of what does each code do. Most of the programs were updated with great success

and were given easy and memorable names for future students to understand the programming

code.

Chapter 5.4 Several Components Faulty/Broken Upon further investigation of the system, it was noticed that there is a leak in the air filter.

Therefore, there was not enough pressure to power the cylinders. A new air filter was fitted which

solved the problem. There also has another issue with LEDs broken and loose wiring cable that has

to replace new LEDs and resolder back for the loose wiring cable.

Chapter 5.5 Communication error At the start of the project, while testing the interface between the software and hardware, it was

found that there was a memory loss while updating the system. Upon examination of the processing

board, it was observed that the ROM was not updating, and RAM was faulty. The solution was to

update the ROM can be referring to the guideline of updating the ROM in Appendix 10D and the

solution for RAM was replaced new RAM.


36

Chapter 6 Future Work This Section is devoted to some of the future works that needs to be carried out, along with some

recommendations and suggestions.

Chapter 6.1 Program Summary The program summary is directed towards student and staff working on the air engine. The

document includes an introduction to the functions of the machine, detail for the main tasks and

relevant information relating to the program. The detailed of the program in Appendix 9 B.

Chapter 6.2 LCD implementation The LCD was used to display the running mode whether manual or auto and also used to show the

speed. However, when implementing the background tasks for each function, it only shows for

manual and auto mode task. For the speed, it does not show anything. To reduce the time of

investigating the speed proceed to the future recommendation.

Chapter 6.3 Wireless Keyboard The current keyboard is working but is not used much since it is preferable to control through the

software. The good idea is to develop a wireless keyboard to control the engine which can be

controlled within a given range rather than sitting near the personal computer (PC).

Chapter 6.4 Additional Programming That would be useful if another program can be developed in LabVIEW to display the status of the

different components such as switches, LEDs, cylinders and more. The idea is to make it easier for

the future student to monitor and control the system in more advance rather than standing near the

machine.

Chapter 6.5 Human Machine Interaction (HMI) control In future, it would be better to develop a system that can be controlled using an HMI. This would be

handy since the user does not have to sit near the control panel to control the engine. A lot of HMIs

are available such as Siemens operated devices [43].

Chapter 6.6 Safety aspect Due time constraint with implemented and commissioned for the overall system successfully run,

the last objective for safety feature has to proceed for next student. The fact of the safety for this

project, that there is a mechanical rotating part it better to make it as safe as possible. A possibility is

to design and implement a clear prospect which will prevent mishaps occurring.


37

Chapter 7 Conclusion The project was a difficult one because there was less information available from previous years.

Due to time constraints and unforeseen circumstances, the time taken to solve the issue between

hardware and software took far longer than expected. Also, since this project was not in use for a

long time, there was a lot of parts that were not working properly. Nevertheless, most of the

objectives were completed, and they are given below:

Air engine operation

o Being able to operate the Air engine by using an M68HC11 microcontroller

Software implementation

o Code updated

o Developing and controlling the engine by two different modes

o Implementing form of control for cylinder firing sequence and maintain the

rotational speed

o Make a significant use of the timing interrupt system capabilities for the input and

output available

o Implement the user interaction via LCD screen

Hardware implementation

o Redesigning the wiring diagram

o Replaced all broken components

o Tidy the wiring connections

o Port mapping to assign the addresses of the board

Skills gain from this project are:

A proper time management schedule,

A more in-depth understanding of the Forth programming language,

Sharpening of the communication skills,

Polishing of the diagnostic and troubleshooting skills,

Have a better insight of how real- time and embedded systems work,


38

Chapter 8 Bibliography [1] T. Finkelstein, A. J. Organ, (2001), “Air Engines: The History, Science, and Reality of the Perfect

Engine”. UK: Professional Engineering Publishing.

[2] H.K. Porter, Inc. “Wikipedia: Compressed Air Locomotive.” (Accessed: 6 August 2015)

[3] “SwiftX 68HC11Target Reference Manual: Internal I/O registers”, Section 3.3., Forth, Inc., LA,

California USA, 2010.

[4] “SwiftX Cross-Development Software Reference Manual”, Forth, Inc., LA, California USA, 2010

[5] E. K. Conklin and E. D. Rather, August 2007, 3rd edition, “Forth Programmer’s Handbook”, Forth

Inc. LA, California.

[6] Motorola INC, 1991, USA, “M68HC11: Reference Manual”, Rev 3.

[7] P. Spasov, 2004, “Microcontroller Technology: The 68HC11 and 68HC12”, 5th Edition.

[8] B.Walker and S.Mackay. (2010), “ENG306 Real Time Embedded System: Air Engine Project,”

Murdoch University, Western Australia.

[9] S. Likhar, "Compressed Air Engine: Create the Future Design Contest", Contest.techbriefs.com,

2016. [Online]. Available: http://contest.techbriefs.com/2013/entries/sustainable-

technologies/3097. [Accessed: 07- Aug- 2016].

[10] K.M. Jagadale and Prof V.R. Gambhire, “Low-Pressure High Torque Quasi Turbine Rotary Air

Engine”, International Journal of Innovative Research in Science, Engineering, and Technology, Vol 3,

Issue 8, August 2014.

[11] B.R. Singh and O. Singh, “A Study of Performance Output of a Multivane Air Engine Applying

Optimal Injection and Vane Angle”, International Journal of Rotating Machinery Vol. (2012).

[12] Ray T. Bohacz, Hemming Classic Car, “Timing Dwell Angle”, October 2013.

[13] SMC Corporation, Tokyo (Japan), P.G. Information, 3 Port Solenoid Valve/VP544-X538,

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41

Chapter 9 Appendices

Appendix 9 A: Microcontroller M68HC11 Based Embedded System Hardware This appendix is providing the technical information relating to the NMIS-0021B, NMIS-7003 and

NMIS-7070 boards schematics and block diagrams. The schematics and diagrams were used to

understand the connections in the air engine and capability and function of each board.

Appendix 9 A.1 NMIS-0021B

Figure 24 and 26 are the NMIS-0021B board microcontroller block diagram and unit layout. The

information for these figures is to understand the board connection.

Figure 24 Microcontroller M68HC11 Block Diagrams [26]


42

Figure 25 NMIS-0021B Unit Layouts [26]


43

Appendix 9 A.2 NMIS 7003

This Figure 26 is the NMIS-7003 board unit layout. The information for this figures is to understand

the board connection for digital I/O terminal and isolation.

Figure 26 NMIS-7003 Unit Layouts [27]


44

Appendix 9 A.3 NMIS-7070

Figure 28 and 29 are the NMIS-7070 board unit layout and schematic respectively. The information

for both figures is to understand the board connection for LCD and keypad controller.

Figure 27 NMIS-7070 Unit Layouts [28]

Appendix 9 B: Forth Air Engine Programming Code This appendix displays the entire Forth for air engine code placed in the RAM. The program consists

of three main files to run the air engine.

1. User code.f

2. Air engine.f

3. Positioninterrupt.f

Appendix 9 B.1 User-code text file (user code.f) This file is in turn loaded by a (debug.f) file which is loaded during a “debug” session. This file is

about all the necessary files that are included, and the required task and heartbeat is initialised. This

main text file is used to create all task required and include all files used to start the programming

code.

Creates all Tasks required:

Task MyHeart

Task Manual

Task AutoMode

Task Initialise

Task StartIt

Task StopIt

Task SpeedCalc

: hello." This is a test”; \ set command code “Hello” to execute and show this is test in the

system


45

Includes All Files Used:

include positioninterupt.f

Include air engine.f

Starts Program Code:

: Doit TestStartup cr .( WELCOME TO MURDOCH AIR ENGINE PROJECT 2016 );

Appendix 9 B.2 Air engine text file (air engine.f) The purpose of this section is to create the user-friendly words that will lead to an easy set up when

developing a state machine model for the background tasks. Each Section of the is broken down into

individual routines, and definitions follow the routine. The specific code relating to other routines

are indicates followed by an individual code are written, and code follows. This text file is required as

follows:

Defines the constant and variables code

set the constant variable code

set the toggle switch and set push button code

creates easy words to store values into address location

Heartbeat task

LCD start-up and keypad setup

Manual Mode code

Creates a mask for a period/scale and offset for firing cylinder for accurate timing

Set Firing points for clockwise and anticlockwise rotation

Speed calculator code

Automatic Routine maintaining speed and auto firing cylinders when within set boundaries

Auto-mode code

o Start engine code

start auto mode if the toggle switches in ON condition

o Kickstart code

Kick start the engine to get movement

o Begin auto code

Suspend the start engine code and run kickstart code

o Ready code

once entering this state check direction switch and then loads different

firing point.

o Switch OFF code

used to show system off and will display in LCD as (welcome)

o Initialise engine code

upon power up, this code is executed whereby all states except heartbeat

and manual mode are suspended

o Stop Engine code

once the toggle switch transition from on/off condition this initialises to

disallow immediate start-up

Set automatic setup and some test words


46

o Test start-up code

To execute the coding that has been selected at the beginning of the system

start.

o Displaycs

This code will show which point the cylinder firing

o Displayp

This code to run the position point sensed by optical sensor encoder.

Appendix 9 B.2.1 Defines Constants and Variables Code

C1 refers to cylinder 1




Output4 refers to output 4 on the board




Out1 refers to output port address @ $8421

Out2 refers to output port address @ $8401

In1 refers to input port address @ $8420

In2 refers to input port address @ $8400

A refers to address variable @ $8421

B refers to address variable @ $8401

Knight-rider refers to the old TV show whereby the lights flashed in a linear sequence. The

developed start-up phase will be similar

Out1on and Out1off refer to $8421 output begin turned on or off through variables. The

purpose of this was to eliminate and reduce coding.

Out2on and Out2off refer to $8401 output begin turned on or off through variables. The

purpose of this was to eliminate and reduce coding.

Hi refers to the start-up welcoming the panel will display until a switch is pressed


47

Appendix 9 B.2.2 Set Constant and Variables

$01 constant c1

$02 constant c2

$04 constant c3

$08 constant c4

$10 constant output4




$FF constant all

$F0 constant bottomhalf

$0F constant tophalf

$8421 constant out1

$8401 constant out2

$8420 constant in1

$8400 constant in2

$8440 constant lcdcmd

$8441 constant lcddat

variable Fire1

variable Fire2

variable Fire3

variable Fire4

variable C1on

variable C1off

variable C2on

variable C2off

variable C3on

variable C3off

variable C4on

variable C4off

variable Periodon

variable Speed

variable StartPoint

variable StopPoint

variable Cylinders

variable A

variable B


48

Appendix 9 B.2.3 Set Toggle Switch Code

This code is to execute the command for read the return of input for ON/OFF and direction toggle

switch.

: OnSwitch? $20 in2 c@ and; \ command for ON/OFF switch

: Direction? $10 in2 c@ and; \ command for direction switch

Appendix 9 B.2.4 Set Push Button Code

This code is to execute the command for read and return of input push button 1,2,3 and 4.

: Push1 c1 in2 c@ and; \ command for Push Button 1 : Push2 c2 in2 c@ and; \ command for Push Button 2 : Push3 c3 in2 c@ and; \ command for Push Button 3 : Push4 c4 in2 c@ and; \ command for Push Button 4

Appendix 9 B.2.5 Creates Easy Words to Store Values into Address Locations

This section is to reduce the programming code setup such instead of typing the address and then

adding and storing the variable a word can be used instead which runs the required routines.

Address $8421 refers to the address of the buzzer, LEDS heartbeat, and direction, relay input board

pin 0 to 3 to trigger the solenoid valve. Address $8401 refers to the address of the LEDs for all

cylinders and outputs.

: store1 A c@ out1 c!; \ Store information for the variable A at address $8421

: store2 B c@ out2 c!; \ Store information for the variable B at address $8401

: out1on A byteclear store1; \ set variable A in Low condition at address $8421

: out1off A byteset store1; \ set variable A in High condition at address $8421

: out2on B byteclear store2; \ set variable B in low condition at address $8401

: out2off B byteset store2; \ set variable B in High condition at address $8401

: initialisesystem all A c! store1 all B c! store2; \ set low condition for all LEDs

: Cylindersoff of all Out1Off; \ set low condition for all cylinders

Appendix 9 B.2.6 Heartbeat Task

This code is to show the heartbeat routine.

: Install Myheart Build; \ command for heartbeat task

: Pulse begin output4 out1on 500 ms output4 out1off 500 ms again; \ code for Heartbeat

flashing

: Something installMyHeart Myheart activate Pulse; \ execute command for heartbeat

Appendix 9 B.2.7 Coding for Buzzer

This code is to run the command to turn ON and OFF buzzer.

: buzzeron output2 out1on ; \ command to activate the buzzer

: buzzeroff output2 out1off ; \ command to deactivate the buzzer


49

Appendix 9 B.2.8 Create code for LEDs flashing

This code is to execute all LEDs flashing ON and OFF in linear sequence.

: Knightrider \ command to execute the code

all out2off

c1 out2on output4 out2on 100 ms

c2 out2on output3 out2on 100 ms

c1 out2off output4 out2off c3 out2on output2 out2on 100 ms

c2 out2off output3 out2off c4 out2on output1 out2on 100 ms

output2 out2off c3 out2off 100 ms all out2off;

Appendix 9 B.2.9 LCD Display Code

This code will show the routine and LCD used for this system.

: !LCD-DAT lcddat c! 40 ms; \ write the character

: !LCD-CMD lcdcmd c! 40 ms; \write command

: @LCD-DAT lcddat c@ 40 ms ; \ read the character

: @LCD-CMD lcdcmd c@ 40 ms; \ read the command

: initialiselcd \ Initialise LCD display

$38 !LCD-CMD \ get attention to display

$38 !LCD-CMD \ set 2 line to display

$38 !LCD-CMD \ set 3 line to display

$6 !LCD-CMD \ Increment cursor

$F !LCD-CMD ; \ set cursor position to 1st line and 1st column

: EmitToLCD lcddat c! ; \ send character to LCD

: ClearLCD $1 !LCD-CMD $1 !LCD-CMD ; \ Clear display screen

: TypeToLCD 0 Do dup c@ EmittoLCD 1 + loop drop ;\ send and show character to display

: Welcome clearlcd s" MURDOCH AIR ENGINE Presented By PROJECT VERSION 2.0

A.R.IBRAHIM 2016 " typetolcd ; \ set the command and show the character to LCD display

: mvprint ( n -- ) swap over abs 0 <# # # #s rot sign #> typetolcd ; \ print the character to and

command to display


50

Appendix 9 B.2.10 Keypad Setup

This code is for setup of the keypad controller for the system. In comment show the key pad control

mapping follow the actual label on the key.

byteTable mapkey

$3 c, $2 c, $1 c, $0 c, \ $3 for (0), $2 for (1), $1 for (2), $0 for (3)


$B c, $A c, $9 c, $8 c, \ $B for (8), $A for (9), $9 for (A), $8 for (B)

$F c, $E c, $D c, $C c, \ $F for (C), $E for (D), $D for (E), $C for (F)


: clearflag 0 $8448 c! ; \ clear keypad controller flag

: dataready? ( -- flag ) $40 $8448 c@ and ; \ set data to keypad terminal

: iskeybeingpressed? ( -- flag ) $80 $8448 c@ and ; \ enables interrupts

: rawkey ( -- key ) $1F $8448 c@ and ; \ set code when keypressed

: whatkeypressed ( -- key ) rawkey mapkey ; \ execute the key pressed code

: pressed iskeybeingpressed? if s" Yes" TypeToLCD then ; \ write key pressed in LCD display

Appendix 9 B.2.11 Manual Mode Code

This code is required the manual routine for manual mode and allows the manual firing of the

cylinder and display the character to LCD during as a background task as shown below.

: Manual1 \ code for manual firing cylinder 1 and turn ON and OFF LED cylinder 1

Push1 if clearLCD s" Manual Mode - Now Firing Cylinder 1" TypeToLCD

c1 out2on c1 out1on 200 ms c1 out2off c1 out1off then ;







: Manual4 \ code for manual firing cylinder, turn ON and OFF LED cylinder 4



: ManualMode Begin Manual1 Manual2 Manual3 Manual4 pause again stop ; \ task for

manual firing sequence

: BuildManual Manual Build Manual activate ManualMode ; \ command to execute manual

mode in multiple extension


51

Appendix 9 B.2.12 Set Cylinder Mask and Offset

This section is set the cylinder mask and offset for the firing the cylinder.

variable xyz \ set variable for XYZ to allow dynamic alteration of OFFSET

: Rotvar $3F and ;

: Offset xyz @ + rotvar ; \ command for offset

: SetCylinderOn Cylinders @ and dup out1on out2on ; \ command to execute Cylinder

Mask code

Appendix 9 B.2.13 Set Firing Point for Clockwise and Anticlockwise Rotation

This code is to execute the command to start firing the cylinder whether in anticlockwise or

clockwise rotation.

: FiringSetupAnticlockwise \ command for Anticlockwise Firing Setup

0 xyz ! 8 periodon ! Cylinders On \ XYZ is variable for offset and PERIODON is variable for

length of firing duration

5 c1on ! 21 c2on ! 37 c3on ! 53 c4on ! ; \ Point for firing Cylinder 1, 2, 3, 4

: FiringSetupClockwise \ command for Clockwise Firing Setup

0 xyz ! 8 periodon ! Cylinders On \ XYZ is variable for offset and PERIODON is variable for

length of firing duration

5 c1on ! 53 c2on ! 37 c3on ! 21 c4on ! ; \ Point for firing Cylinder 1, 2, 3, 4

: AntiClockwise FiringSetupAnticlockwise Output3 Out1Off 0 Revolution c! ; \command code to

execute anticlockwise

: Clockwise FiringSetupClockwise Output3 out1ON -1 Revolution c! ; \ command code to execute

clockwise

Appendix 9 B.2.14 Speed Calculator Command and Task

This task is to calculate the rotation speed

: RPM begin Revolution @ StartPoint ! 2000 ms Revolution @ StopPoint ! \ RPM is initial

variable for speed task

StartPoint @ StopPoint @ - 30 * Speed ! Speed @ 0 and if

ClearLCD s" Auto Mode " s" Not Moving or Accelerating" TypeToLcd else

ClearLCD s" Auto Mode " speed @ mvprint s" " TypetoLCD s" RPM" TypetoLCD

0 Revolution ! 0 StartPoint ! 0 StopPoint ! then pause again stop ;

: BuildSpeed SpeedCalc Build SpeedCalc ACTIVATE RPM ; \ command to execute speed task

Appendix 9 B.2.15 Automatic Firing Cylinder Routine for Maintaining Speed

This task is for simpler and execute the firing sequence for cylinder with dynamic period.


52

: FiringCylinders \ command for firing cylinder task

Position @ offset c1on @ dup PeriodOn @ + within

if c1 SetCylinderOn else c1 dup out1off out2off then






if c4 SetCylinderOn else c4 dup out1off out2off then ;

Appendix 9 B.2.16 Automatic Mode Code

The automatic mode code is consisting of start engine, kick start, begin auto, ready, initialise and

stop engine. To start the auto mode task, have to write in command window “buildautomode”, once

it done the program will execute the “startengine” code and suspend for the other task includes

manual mode, stop engine, begin auto and initialise engine. After that, it continues with selecting

the direction whether clockwise or anti-clockwise firing sequence. To stop the auto mode task write

in command window “buildstopit”, the program will execute the “stopengine” code and suspend all

task.

: StartEngine \ starting command when execute automode

begin StartIt suspend tophalf out2off

OnSwitch? clearLCD s" Auto Mode - Now Firing Cylinder Routine" TypeToLCD

Direction? if anticlockwise else clockwise then

if FiringCylinders else StopIt resume then pause again stop;

: KickStart \ to get movement and readings into the rotary encoder variables

c1 dup out1on out2on 400 ms c1 dup out1off out2off

c4 dup out1on out2on 400 msc4 dup out1off out2off;

: BeginAuto \ to execute and run kickstart command automatically

begin pause tophalf out2off output2 out2on

Initialise SUSPEND StopIt SUSPEND Manual SUSPEND

output2 out2on kickstart AutoMode RESUME again stop ;

: Ready \ once entering this command then loads different firing point


53

Direction? If anticlockwise else clockwise then

all out2on 100 ms all out2off 100 ms all out2on 100 ms all out2off 100 ms

Onswitch? if all out2off StartIt resume then;

: SwitchOff \ to execute knightrider code

OnSwitch? Not Knightrider ClearLCD Welcome;

: InitEngine \ to run all state except heartbeat and manual mode

all out2off clearlcd welcome begin pause

StopIt SUSPEND Manual RESUME SpeedCalc SUSPEND

OnSwitch? if Ready else SwitchOff then again stop ;

: StopEngine \ to execute all state in stop condition

Begin AutoMode SUSPEND SpeedCalc SUSPEND

tophalf out2off output1 out2on cylindersoff 1000 ms

OnSwitch? Not if Initialise RESUME Manual SUSPEND

then pause again stop;

Appendix 9 B.2.17 Creates the Auto Mode Task

This is selected task to execute the system while running in auto mode.

: BuildAutoMode Automode build Automode activate StartEngine; \ command for start

engine task

: BuildStartIt StartIt Build StartIt Activate BeginAuto ; \command for begin auto task

: BuildInitialise Initialise Build Initialise ACTIVATE InitEngine ;\ command for initializing task

: BuildStopIt StopIt Build StopIt Activate StopEngine ; \command for stop engine task

Appendix 9 B.2.18 Automatic Start-Up and Testing words

This code is to execute the start-up, beginning with the system, display the firing point of the

cylinder and the current position for rotary encoder disk hole detected.

: TestStartup initialisesystem buildposition initialiselcd welcome buzzeron 2000 ms; \

execute the start-up and beginning of the system

: displaycs c1on? c2on ? c3on ? c4on ?; \ execute to display firing cylinder point

: displayp begin position @ u. 100 ms cr key? Until; \execute the current position of

encoder disk


54

Appendix 9 B.3 Position Interrupt Text File (Positioninterupt.f) The Section is to create the interrupts which store the variables that are to be used for the rotary

encoder.

TDC Top Dead Centre and is the reference point.

Position refers to the current position of the encoder

TIC-2 interrupts every time TDC is passed

TIC-1 interrupts at every position

Position refers to current position of rotor and increments by 1 till 64 then resets

Revolution refers to the amount revolutions the rotor passed TDC (TDC point is 0)

Through investigation, it was determined that the encoder reference points i.e. TDC and position

were located at the interrupts TIC-2 and TIC-1 respectively. From here upon each interrupt the

variable is loaded, incremented and then stored through register D. However, whenever the TDC

reference point went past the Revolution counter would increment and reset the position variable.

The interrupt loads the values of the variable position of small holes into the accumulator (A) which

is then incremented by one and the new value stored again in the accumulator (A). The interrupt flag

register is then loaded with the value $04 to clear interrupts. The interrupt flag was set to capture a

rising edge on the input to examine if the flag was raised on such a rising edge event. The interrupt

was enabled using the tmsk1 enabler.

This file is including:

Set variable used

TIC-2 interrupts for revolution is loaded into direction and position is reset to zero.

TIC-1 interrupts for the position is loaded into direction and position is after reset to zero in

the revolution.

Appendix 9 B.3.1 Set Variables for position interrupts

variable position

variable Revolution

variable prime

variable period

variable TDCTime

: startint_tic %00000110 tmsk1 c! %00000110 tflg1 c! %00010100 tctl2 c! ; \ enable

interrupt,

\ every time TIC-2 interrupts revolution is loaded into direction and position is reset to zero

label <TopDeadCenter>

Revolution ldd 1 # addd Revolution std \Load position into revolution

0 # ldd position std \load 0 into position


55

TIC2 ldd TDCTime std \Store TIC2 as time of TDC interrupt

$02 # ldaa tflg1 staa <rti> jmp \reset interrupt flag

rti end-code \ return from interrupt

\ every time TIC-2 interrupts revolution is loaded into direction and position is reset to zero

label <position>

position ldd 1 # addd position std \Increments position by 1

tic1 ldd ptime std \loads TIC time into position time

$04 # ldaa tflg1 staa <rti> jmp \reset interrupt flag

rti end-code \ return from interrupt

Appendix 9 B.3.2 Creates Interrupts Task

: Vectorposition <position> V-TIC1 exception ; \start interrupt TIC1

: VectorTopDeadCenter <TopDeadCenter> V-TIC2 exception ; \start interrupt TIC2

: Buildposition startint_tic VectorTopDeadCenter Vectorposition ; \ execute interrupts TIC1

and TIC2

Appendix 9 C: Air Engine Hardware This appendix is providing the further information of specification for hardware used for this project.

Appendix 9 C.1 Solenoid Valve

Figure 28 SMC Solenoid Valves [15]


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Table 10 Solenoid Valve Specification [15]

Model VP544

Fluid Air

Type of actuation Normally Close (NC- Return Spring)

Operating pressure range 0.25 to 0.7MPa

Operation Internal pilot type

External pilot pressure None

Maximum operating frequency 30 times per minute

Minimum operating frequency 1 time per week

Ambient and fluid temperature -10 to 50 degree(C) (No freezing)

Ambient 20 to 90 percentage-RH (No freezing)

Lubrication No required

Shock or Vibration (150/30) meter per second square

Enclosure IP65

Operating environment Indoors

Weight 930 grams

B10d(MTTFd Calculation) 10000000 times

Rated of voltage 24 VDC

Power consumption 0.45 watt(W)


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Appendix 9 C.2 Pneumatic Cylinder Specification

Figure 29 SMC Clamp Pneumatic Cylinder [16]

Table 11 Pneumatic Cylinder Specification [16]

Fluid Air

Proof pressure 1.5 Mpa

Maximum operating pressure 1.0 Mpa

Minimum operating pressure 0.05 Mpa

Ambient and fluid pressure -10 to 60 degree

Piston speed 50 to 500 mm/s

Speed controller Equipped on both end

Lubrication Non-lube

Stroke length tolerance 0 to 1.0


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Appendix 9 C.3 Air Filter Regulation Specification Table 12 Air Filter Regulation Specification [18]

Fluid Air

Proof pressure 1.5 Mpa

Maximum operating pressure 1.0 Mpa

Set pressure range 0.05 to 0.85 Mpa

Ambient and fluid pressure -5 to 60 degree, c

Nominal filtering rating 5 micro minute

Drain capacity 25

Bowl material Polycarbonate

Bowl guard Standard

Construction Relieving type

Mass 0.4 kg

Appendix 9 C.4 Optical Sensor

Figure 30 Optical Sensors OPB815W [36]


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Table 13 Optical Sensor Specification [36]

Part Number OPB815W

Storage & operating temperature range -40 to 80 degree, c

Continuous forward current 50 mA

Reverse voltage 2 V

Power dissipation 100 mW (milliwatt)

Collector to Emitter Voltage 30 V

Emitter to Collector voltage 5 V

Forward voltage 1.7 V

Appendix 9 D: ROM Updating Process ROM modification is required due to non-updated ROM. There is guideline for ROM updating as

listed below:

1. Initially, open the project and press the build button.

2. If any error appears then build and debug again, which will update the target S19 file.

3. To ensure step 2 was completed correctly, check the last updated time.

4. Use ultraviolet eraser to wipe out the current code on the EEPROM, which is a lengthy

process usually taking more than an hour

5. Insert an empty chip into the ALL-11 Universal Programmer then switch ON.

6. Open the WACCESS program from start menu on the PC, then press the device button to

pop-up the manufacture selected list window as shown in Figure 33.

7. Select the appropriate chip manufacturer then it will bring up the status program window as

shown in Figure 34.

8. From the file tab chose: ‘load the file to program buffer’ then select the target file built. The

file format window will pop up as shown in Figure 35, then select Motorola S-Record, for

Unused Bytes select (FF), and for file status makes sure the file start has to 00008000 and

the file end has to 001FFFFF, then press OK.

9. To check the updated chip, select “edit program buffer” from edit tab then the editor

window will pop up as shown in Figure 36, on the right of editor window will display symbol

selection and toward on the bottom of the symbol area will be show the GREET message and

check the last date has been updated. Once it did, close the window.

10. Continue with the press the Auto button to pop up the auto window as shown in Figure 37,

then select the ID check, blank check, program and verify box. If the still have the error, the

chip may be faulty.

11. Lastly, insert the updated ROM into the processor board and make sure all the system is

turned off before insert the ROM.


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Figure 31 Manufacture Selection List Window

Figure 32 Program Status Window


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Figure 33 File Format Window

Figure 34 Editor Window


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Figure 35 Auto Window

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