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LABVIEW BASED REALTIME INTEGRATED SAFETY PARAMETERS MONITORING

OF UAV

AMIYA RANJAN PANDA1, ANGSHUMAN ROY2, UTPAL MANDAL3 & HARE KRISHNA RATHA4

1Junior Research Fellow, Integrated Test Range, Defence R&D Organization, Balasore, India

2,3,4Scientist, Integrated Test Range, Defence R&D Organization, Balasore, India

ABSTRACT

This paper describes the necessity and implementation of LabVIEW based integrated Command Transmission

System monitoring and logging system. The existing Command Transmission System did not have facility to log both

ground and flight Command Transmission System parameters simultaneously synchronized to Accumulated Time of the

Day (ATD). Moreover real time monitoring of Command Transmission System parameters was not possible. To overcome

these bottlenecks, this integrated system was conceptualized and developed based on LabVIEW. LabVIEW was used for

providing Graphical User Interface (GUI) and reduction in development time. The system can simultaneously receive data

from Onboard and Ground Command Transmission System through Ethernet and parallel port respectively. Hence all the

Command Transmission System parameters can be monitored and logged in real time. The system uses the User Datagram

Protocol (UDP) unicast Ethernet communication because it can be used when data transfer rates are more or application

transmit informative data to a destination frequently enough that a few lost segments of data are not problematic. All

computers have Ethernet ports now a days, so no extra hardware is needed other than a cable to connect instrument to the

computer. The data recorded in the logging file is used for future analysis.

KEYWORDS: Command Transmission System, LabVIEW, Ethernet Communication, Parallel Port Communication

INTRODUCTION

Command Transmission System

A newly developed Unmanned Aerial Vehicle (UAV) needs rigorous testing to satisfy all expected performance.

When testing the UAV dynamically, there are lots of uncertainties regarding the flight performance. Hence at test facility, a

flight termination system is utilized to secure the life and property. Command Transmission System (CTS) basically

involves in generation and transmission of remote command signals to the airborne flight vehicle to execute some operation

inside the vehicle as required.

Function of CT System: Command Transmission System is used for termination of flight vehicle under test.

Termination of test vehicle is mandatory if the vehicle deviates from its preset trajectory and takes different course due to

unpredictable failures of onboard system. In such cases destruct command is transmitted from ground Command

Transmission System for termination of test vehicle. The commands are transmitted when required during testing.

Commands: Command Transmission System transmits four types of commands (Command 1, Command 2,

Command 3 and Command 4). Command 1 confirms CTS link, ensures no inadvertent arming. Command 2 activates

Command 3 and Command 4. Command 3 stops flow of liquid propellant. Command 4 destroys the test vehicle. Command

1 is transmitted all the time. During termination time Command 4 is transmitted followed by Command 2 and Command 3.

Command 3 is not used in case there is no liquid propellant in the flight. Command 3 is otherwise known as Thrust

Termination command.

International Journal of Computer Science Engineeringand Information Technology Research (IJCSEITR)

ISSN 2249-6831

Vol. 3, Issue 1, Mar 2013, 1-10

© TJPRC Pvt. Ltd.



2 Amiya Ranjan Panda, Angshuman Roy, Utpal Mandal & Hare Krishna Ratha

Requirements

The commands transmitted by transmitter system is received and decoded by on board CTS receiver. The decoded

commands are framed and telemeter by telemetry link. The ground telemetry system, after reception of the data sends to

CTS system for validation. An integrated display application was required which could monitor all CTS related parameters

along with ground system parameters.

The developed application can monitor all the required parameters and also logs all values in specified text file with

respect to the time which is synchronized with Network Time Protocol (NTP) server and can be viewed and monitored in a

single front panel window. Previously, strip chart recorder was available for recording the issued command status from

ground Command Transmission System but that was not sufficient to monitor all the parameters received from on board

package and in this consequence; the strip chart recording system was not synchronized with ATD time. But this new system

is capable of monitoring all the Command Transmission System related parameters and on board status parameters. More

than 24 parameters are logged and monitored by this system during real-time.

System Configuration

Figure 1: System Configuration

This system takes the command status and system chain status information from the Ground Command

Transmission System through parallel port of PC and on-board CTS related parameters from Telemetry stations via server

computer to display the command received by flight vehicle through Ethernet. Telemetry stations continuously receive the

health parameters and safety parameters (Command Transmission System parameters) from on board package of the test

vehicle. Telemetry stations are geographically located at distance along surveyed path to cover the trajectory of flight.

Although data from multiple telemetry stations are received but any two of the station data are displayed for better visibility.

The system unicasts total display data to remote safety officer room.

LABVIEW

LabVIEW Implementation

Lab VIEW is an inventive graphical programming system which helps to design computer-controlled data

acquisition and analysis system [1]. LabVIEW provides an ideal scope to carry out computer-based research. The wired-

together icons to perform simple-to-understand tasks of LabVIEW make operations given below possible.



LabVIEW Based Realtime Integrated Safety Parameters Monitoring of UAV 3

1. Building an array

2. Parsing a string

3. Digitizing an analog voltage

Once a LabVIEW program is created and understood the modularity nature of it facilitates to include in the library

that can be used later for more complicated program.

LabVIEW Program Interface

A Lab VIEW program includes two windows, called the Front Panel and the Block Diagram.

Virtual Instruments (VI)

LabVIEW programs are called Virtual Instruments (VI) because their appearance and operation imitate physical

instruments, such as oscilloscopes and multi meters [1]. Every VI uses functions that manipulate input from the user interface or

other sources and display that information or move it to other files or other computers.

The Front Panel

Once a program is developed, the front panel acts as the face of a laboratory instrument. Front panel includes

controls and indicators, which are the interactive input and output terminals of the VI, respectively. Controls are knobs,

push buttons, dials, and other input mechanisms. Indicators are graphs, LEDs, and other output displays. Hence the front

panel is the program’s user-interface, which facilitates the interaction of:

1. Providing inputs to the program,

2. Monitoring outputs from the program as it runs.

The Block Diagram

The actual LabVIEW programming code is shown in the block diagram. It contains LabView’s well-stocked

libraries of icons that we have selected during the program development. Each icon stands for a block of underlying

executable code that performs a particular useful function. The programming is done by wiring these icons properly, so

that data flows amongst graphical images to achieve a desired function.

Lab VIEW enables us to carry out state of the art research including:

1. Instrument Control

2. Data Acquisition

3. Data Analysis

4. Data Presentation and Data Storage.

SOFTWARE IMPLEMENTATION

The developed application comprises of two units. 1. Data reception through Ethernet 2.Data reception through

parallel port. In each of the above case data reception is followed by data processing and data presentation which has

shown in figure 2.




Figure 2: Data Flow in Integrated Command Transmission System Display Unit

Data Reception Through Ethernet

First the UDP socket is opened then the data reception is done. After that buffer size is matched and then the

control goes to the required unit accordingly. If the buffer size mismatch occurs then the socket is made close, otherwise

control goes to conversion unit. The data received through UDP unit is clustered together and goes to the station selector unit

where data is uncluttered and populated in the display unit. The stations are selected in the front panel window through the

drop down list control. Data from these selected telemetry stations can be shown at a time on the front panel window. The

above mentioned procedure is shown in figure 3. Apart from the above procedure, the data logging facility is available in the

application, which records Command Transmission System related data from all telemetry stations irrespective of selection.

User can log data by selecting ‘logger-on’ on front panel window. The logging unit takes the data from data reception unit

(UDP data) and writing it in a text file. The logging can be done in every hundred millisecond and also the updation on the

front panel is done at the same rate. Here, sender’s data transfer rate is greater than or equal to receiving rate.

Figure 3: Flowchart of Data Reception through Ethernet

For post flight analysis the application takes the data from the logging file to create real time flight scenario. The

data flow diagram depicting the post flight analysis is shown in figure 4.




Figure 4: Data Flow During Post Flight Analysis

Data Reception through Parallel Port

In general parallel port is of outward type. In this application data needs to be received through parallel port. For

this reason control register of the port was initiated to set the C5 bit to logic 1 (high) [2]. To access the data in parallel port

using LabVIEW, the port status of the computer has to be changed to SPP mode in BIOS. In paper [3] serial port

communication has been implemented using LabVIEW and similarly paper [4] gives serial port communication with VC

mixed approach. In parallel port first the register addresses (Data register, Status register, Control register) are validated.

Then the data will be written in to the register read /write unit. Then label comparison is done followed by bit conversion.

After that data will be populated in display unit. Figure 5 shows the above mentioned procedure.

Figure 5: Flow Chart of Data Reception through Parallel Port

IMPORTANT FEATURES

1. Application is synchronized with NTP server. So real time data validation can be possible.

2. Validation of transmitting ground Command Transmission System parameters are possible by receiving the signal

from on board package.

3. Signal strength monitoring of on board Command Transmission System is possible.

4. Real-time STR (Safety Timer Relay) status can be monitored.

5. PCM lock status of all participating Telemetry stations can be monitored.

6. With respect to UAV on board package performance of the participating telemetry stations can be compared

relevant to Command Transmission System point of view.




7. Real time sequence of commands passed from ground Command Transmission System systems can be validated.

8. Simultaneous logging of all on board and ground Command Transmission System parameters is recorded for post

flight analysis.

9. The Command Transmission System parameters can be monitored from the Logging file.

10. Ethernet link connectivity status can be monitored and unicast receiving port address can also be changed which

enhance the flexibility of the system.

11. Ground Command Transmission System chain configuration can be monitored.

12. If required, more number of telemetry stations can be incorporated into this application in future to track long

range flight.

13. Total display information can be unicasted to display in remote monitoring stations.

RESULTS

Figure 6: Integrated Command Transmission System Display Unit

Figure 7: Data Logged into the Logging File




Figure 8: Block Diagram Showing Data Reception through Ethernet

Figure 9: Block Diagram Showing Data Reception through Parallel Port

Figure 6 represents the integrated Command Transmission System display unit. This is broken into different sub

window for better description purpose. Figure 7 represents the data logged into the logging file. Data are logged with

respect to ATD. Figure 8 shows the code window showing data reception through Ethernet. Figure 9 shows the code

window showing data reception through parallel port [7] [8].

Figure 10: Displaying Transmitting Command and Selected Chain

Figure 10 represents the status of command transmitted from Ground Command Transmission System and chain

configuration.

Figure 11: Selection of Telemetry Stations from Dropdown List




Figure 11 represents the selection of participating Telemetry stations from the existing list of Telemetry stations

and the strength of the commands received by the on board Command Transmission System package.

Figure 12: Displaying Receiving Status, Logging Key and ATD Time

Figure 12 represents Ethernet connectivity link status, logging control switch and ATD synchronized to the NTP

server. ATD TIME DISPLAY unit displays the current system time which are synchronized to the NTP server.

Figure 13: Signal Strength Vs Time

Figure 13 is a graphical chart displaying the variation of signal strength with respect to ATD time during the

future analysis.

Figure 14: Safety Rly Vs Time

Figure 14 is a graphical chart displaying the Safety relay status during the flight test time with respect to ATD

time.This is generally analyzed during the post flight analysis.




Figure 15: Com 1, Com 2, Com 3, Com 4 Vs Time

Figure 15 shows the graphical chart for transmission of COM 1, COM 2, COM 3, COM 4 signal with respect to

time. If the strength is one then COM 1 is transmitted and COM 1 is not transmitted if the strength is zero. This is same for

all other commands.

CONCLUSIONS

The application has been tested and validated in various test in the recent past. The system performed

satisfactorily for real time monitoring and logging. Moreover the logged data can be used for post flight analysis. This

application has also been extended to Safety Officer.

In future this facility can be multicasted to other decision making authorities for integrated monitoring of

Command Transmission System. This design approach can be implemented for other application that receives data from

multiple sources, process as per requirements, monitor, log and transmit data to other units.

REFERENCES

1. Lab VIEW 2009 by National Instruments, http://www.ni.com.

2. Lab View Graphical Programming by Gary W johnsion (TMH).

3. Amiya Ranjan Panda; Utpal Mandal; HareKrishna Ratha, “Integrated Monitoring of Encoder Status Parameters

and GUI based Remote Control Panel Using LabVIEW”, International Journal of Computer Application (0975 –

8887), Volume 43– No.3, April 2012, PP21-26.

4. Zhou Hongfu; Xiao Xinyan; Tang Yong, “Serial Communication Interface Design Based on Lab VIEW and VC

Mix Programming”, 8th International Conference on Electronic Measurement & Instruments, (ICEMI2007) PP44-

49, (in English) (ISTP/EI, INSPEC).

5. Machacek J.; Drapela J, “CONTROL OF SERIAL PORT (RS-232) COMMUNICATION IN Lab VIEW”, 9th

International Conference Modern Technique and Technologies, (MTT 2008) PP36-40.

6. Joan Marler and Frank Nezrick, 877,"Interferometer Digital Feedback and Control System", Fermi National

Accelerator Laboratory, 1998, Internal Note 877-23.




7. Svinov, A.; Turygin, Y.V.; Sitar, J, “Remote control system and its development for linear asynchronous motor”,

MECHATRONIKA, 2010, 13th International Symposium, PP 105 – 108.

8. Joan Marler and Frank Nezrick, 877,"Interferometer Digital Feedback and Control System", Fermi National

Accelerator Laboratory, 1998, Internal Note 877-23.

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