shake and bake: preliminary design report goods... · web viewthe maximum mass found based on the...
TRANSCRIPT
Preliminary Design Report(Shake and Bake)
Andrew TownsendRyan JohnsonKara Tobey
Aldo CamposGrant Arthur
Shake and Bake: Preliminary Design Report October 12, 2011
Table of Contents
Background......................................................................................................................................3
Principles of Operation....................................................................................................................4
System Description and Block Diagrams........................................................................................5
Power Supply...........................................................................................................................7
User Interface...........................................................................................................................9
Control Unit............................................................................................................................12
Dispensing Unit......................................................................................................................15
System Analysis.............................................................................................................................17
Extrusion Screw and Housing Design....................................................................................18
Motors and Gearing................................................................................................................21
Program Design......................................................................................................................22
Project Plan....................................................................................................................................24
Organization and Management..............................................................................................25
Budget....................................................................................................................................26
Gantt Chart Fall 2011.............................................................................................................27
Gantt Chart Spring 2012.........................................................................................................28
Pert Chart Fall 2011...............................................................................................................29
Pert Chart Spring 2012...........................................................................................................30
Work Breakdown Structure Fall 2011....................................................................................31
Work Breakdown Structure Spring 2012...............................................................................33
Appendix A:...................................................................................................................................36
2
Shake and Bake: Preliminary Design Report October 12, 2011
Background
Fresh-baked cookies, banana bread, and hot biscuits are integral to American culture.
Hundreds of such deserts, breads and pastries are made by household cooks every year, from
small children standing on chairs to the moms who help them stir to great-grandmothers who
have prepared such treats for several generations. Small-scale baking is a ubiquitous activity
which captures the attention of many. Every local coffee shop hides someone whipping up a
batch of blueberry scones in the back, and many small restaurants offer their own homemade
desserts.
The system of measuring out ingredients for such projects is a standard process that has
remained steadfast for generations. The process is simple, but time-consuming and messy.
Frequently, ingredients are spilled onto the countertop or floor during measuring. If a scoop
needs to be reused, it must be washed first in order to avoid contamination and all measuring
utensils must be washed again at the end of the process. This cleaning up is generally detested
by bakers, who would rather spend their time on other activities. Also, accuracy is sacrificed
when the baker is in a hurry and doesn’t have time for exact measurements.
A device capable of making accurate measurements without the need for cleanup would
make baking much more enjoyable for users. The Shake and Bake ingredient dispenser speeds
up and cleans up the baking process, allowing cooks to focus on other elements of their work,
rather than fussing with measurements. The machine’s functions greatly simplify the common
but inefficient process that includes opening containers, retrieving measuring utensils, measuring
out ingredients, cleaning up spills, closing containers, and washing utensils.
This device measures out dry ingredients common to baking in increments specified by
the user. In addition to delivering accurate quantities in a timely manner, it stores the ingredients
and keeps them fresh, dry and clean. It eliminates spills, the need to search for and wash
measuring cups and spoons, and the headache of maneuvering many different containers. Also,
the device can store previously used recipes and doesn’t forget how many cups it has measured
already, as cooks are notorious for doing. The ingredient dispenser generally creates a cleaner,
more efficient baking environment.
3
Shake and Bake: Preliminary Design Report October 12, 2011
Principles of Operation
The ingredient dispenser will store six different ingredients (flour, white sugar, brown
sugar, salt, baking soda, and baking powder) in sealed containers made of FDA-approved
materials. It will take input from the user, allowing measurements to be specified in cups,
tablespoons, teaspoons, or grams. It will then dispense the ingredients in amounts accurate to
within 5% of the user input. It will store at least five recipes in memory, allowing the user to
recall them instead of manually entering commonly used recipes repeatedly. The machine will
communicate with the user visually via a LCD screen.
The device will perform more quickly than a human measuring by hand (including
retrieving, using, washing and putting away necessary instruments). It will dispense one cup of
flour, white sugar, or brown sugar in 75 s or less and one tablespoon of salt, baking soda or
baking powder in 75 s or less. The containers will be easily detachable, making them easy to
clean. The finished structure will be easy to move and store, weighing no more than 15 kg when
empty, and having dimensions no more than 0.5 m wide by 1.0 m long. It will be no noisier than
other kitchen appliances, producing less than 90 dB at a distance of 1 m.
4
Shake and Bake: Preliminary Design Report October 12, 2011
The ingredient dispenser consists of four primary subsystems: the power supply, the user
interface, the control unit, and the dispensing unit. The relationships between these four
components are shown in Fig. 1. The power supply provides electrical power to the other three
units. The user interface communicates with the user, receiving commands and providing
information about the dispensing status. The control unit determines the ingredient and the
amount of that ingredient to be dispensed. The dispensing unit transfers the ingredients out of
the unit for use by the user.
Figure 1: Level 1 Functional Block Diagram for Device
These four units are further decomposed in level 2 block diagrams on the following
pages. For all diagrams, the inputs and outputs for each unit are indicated with arrows. Dotted
lines represent a signal, solid lines represent power, and bold lines represent materials.
6
Shake and Bake: Preliminary Design Report October 12, 2011
Power Supply
The power supply converts a 120 V AC signal from a standard home wall socket into a
12 V DC signal. It then steps this voltage down to the amounts required by the various electrical
units used in the device. The power is supplied to the microprocessor, memory, keypad, scanner,
screen, sensors and motors. The power supply will be purchased or built to meet requirements.
The level 2 block diagram for the power supply is shown in Fig. 2. This diagram includes the
components that will be needed if the power supply is built.
Input 120 V AC from wall
Output 5 V DC, 45 mA to microprocessor
5 V DC, 3 mA to memory
5 V DC, 45 mA to keypad
5 V DC, 25-80 mA to scanner
3.3 V DC, 8.6 mA to LCD screen for logic
12 V DC, 20 mA to LCD screen for backlight
5 V DC, 2 mA to each sensor
12 V DC, 82 mA to each motor
7
Shake and Bake: Preliminary Design Report October 12, 2011
Figure 2: Level 2 Functional Block Diagram for Power Supply
AC Voltage Step Down
This component drops the incoming 120 V AC to 20 V AC.
Rectification
Diodes are used to rectify the AC signal.
Filter to Remove Ripple
A filter is used to stabilize the signal, creating a steady output.
DC Step Down
Three DC step down components reduce the 20 V to the voltages required by the various
components that are powered by the power supply. The voltage is first stepped down to 12 V,
which is used to power the motors and the screen backlight. It is then stepped down to 5 V,
8
Shake and Bake: Preliminary Design Report October 12, 2011
which is used to power the microprocessor, memory, sensors, keypad and scanner. Finally, the
voltage is stepped down to 3.3 V, which is used to power the screen logic.
User Interface
The user interface is the system through which the device communicates with the user,
prompting the user for input, receiving commands, and providing information about the
dispenser’s status. It consists of a keypad, barcode scanner, on/off switch, and LCD screen. The
level 2 block diagram for the user interface is show in Fig. 3.
Figure 3: Level 2 Functional Block Diagram for User Interface
9
Shake and Bake: Preliminary Design Report October 12, 2011
KeypadThe keypad takes input from the user, who chooses the desired ingredient and
measurement combinations, which are then sent to the microprocessor.
Input Power 5 V DC, .5 mA
Mechanical signal from user pushing keypad buttons
Output Digital signal to microprocessor 0-5 V DC, 0.5 mA
ScannerThe scanner reads barcodes that contain recipes (combinations of ingredients and their
corresponding measurements) and sends this information to the microprocessor.
Input Power 5 V DC, 25-80 mA
Values encoded in barcode provided by user
Output Digital signal to microprocessor 0-5 V DC, 0.5 mA
SwitchA mechanically operated switch is the means by which the user tells the device to begin
dispensing. Each container has its own switch which, when engaged, connects the corresponding
motor to the power supply. If the microprocessor has sent a signal to the motor at this point,
engaging the switch will cause the motor to begin rotating.
Input Power 12 V, 82 mA
Mechanical manipulation by user
Output 12 V, 82 mA to motor (each)
10
Shake and Bake: Preliminary Design Report October 12, 2011
LCD ScreenAn LCD screen outputs information from the microprocessor to the user. The screen is
used to interact with the user and provides information about which containers are currently
programmed, what measurements have been entered, and which recipes are stored.
Input Power 3.3 V, 8.6 mA
Power 3.3 V, 20 mA
Digital signal from microprocessor 0-5 V DC, 0.5 mA
Output Visual output to user
11
Shake and Bake: Preliminary Design Report October 12, 2011
Control Unit
The control unit consists of the microprocessor, memory and sensors. The control unit
controls and monitors the dispensing process. It gathers information about the container weights
from the sensors, sends information to and retrieves information from the user interface, and
signals the motors to turn on or off. The level 2 block diagram for the control unit is shown in
Fig. 4.
Figure 4: Level 2 Functional Block Diagram for Control Unit
12
Shake and Bake: Preliminary Design Report October 12, 2011
MicroprocessorThe microprocessor takes information from the user via the keypad and scanner. It
controls which containers dispense and how much ingredient they dispense based on user input.
The microprocessor controls dispensing by engaging and disengaging the motors. It gathers
information about the containers through the force sensors, monitoring the amount of ingredient
in a container throughout the dispensing process. The microprocessor communicates to the user
with a screen.
Input Power 5 V DC, 45 mA
Analog signals from sensors 0-2 V DC, 0.5 mA
Digital signal from keypad 0-5 V DC, 0.5 mA
Digital signal from scanner 0-5 V DC, 0.5 mA
Digital signal from memory 0-5 V DC, 3 mA
Output Digital signal to motor 0-5 V, 0.5 mA (each)
Digital signal to LCD screen 0-5 V, 0.5 mA
Digital signal to memory 0-5 V, 0.5 mA
MemoryMemory, which may be internal or external to the microprocessor, stores combinations of
ingredients as recipes. This allows the user to recall and use stored recipes.
Input Power 5 V DC, 3 mA
Digital signal from microprocessor 0-5 V DC, 0.5 mA
Output Digital signal to microprocessor 0-5 V DC, 3 mA
13
Shake and Bake: Preliminary Design Report October 12, 2011
SensorsForce sensors measure the weight of each container and send this information to the
microprocessor, allowing the microprocessor to monitor the amounts of ingredients in each
container. During dispensing, the microprocessor uses the change in weight of a container to
determine how much of an ingredient has been dispensed.
Input Power 5 V DC, 2 mA (each)
0-35 N force from containers
Output Digital signal to microprocessor 0-5 V DC, 0.5 mA
14
Shake and Bake: Preliminary Design Report October 12, 2011
Dispensing Unit
The dispensing unit consists of the ingredient containers, dispensing mechanisms and
motors. This system holds the ingredients and uses mechanical power to move the ingredients
out of the containers. The level 2 block diagram for this unit is shown in Fig. 5. Descriptions of
each component follow.
Figure 5: Level 2 Functional Block Diagram for Dispensing Unit
15
Shake and Bake: Preliminary Design Report October 12, 2011
ContainersSix separate containers will be used to hold various ingredients. There are two different
container sizes. The three larger containers are designed to hold flour, white sugar, and brown
sugar. Three smaller containers hold salt, baking soda, and baking powder.
Input Ingredients, from user
Output Ingredients, to dispensing mechanism
0-35 N force, to sensors
Dispensing MechanismThe dispensing mechanism is a mechanical assembly used to move ingredients out of the
containers and into a receptacle provided by the user. The main component is a threaded screw
which pushes the ingredient as it rotates. This screw is turned by a geared motor.
Input Ingredients, from containers
Mechanical torque from motors
Output Ingredients, to user
MotorsThe motors mechanically power the dispensing mechanism. They are turned on and off
by the microprocessor when it receives instructions for a container. In addition, the motors will
take a signal from the user via the “dispense now” mechanism, engaging only when the user is
ready for dispensing.
Input Power 12 V, 82 mA each (from switch)
Digital signal from microprocessor 0-5 V, 0.5 mA (each)
Output Mechanical torque applied to dispensing mechanism
16
Shake and Bake: Preliminary Design Report October 12, 2011
Extrusion Screw and Housing Design
Table 1 displays the material densities gathered from a chart published on simetric.co.uk.
Using these densities, a rudimentary screw and screw housing design have been started.
Table 1: Ingredient Densities
Ingredient Density (Kg/m^3) Density (Lb/in^3)flour 593.00 0.0214sugar 849.00 0.0307brown sugar 721.00 0.0260salt 1200.00 0.0434baking powder 721.00 0.0260baking soda 689.00 0.0249
As seen in Table 1, the salt has the highest density; therefore one would surmise that the
dispensing design will be critical on the salt properties because of the higher amount of mass in
the system when salt is used. However, the information that is actually critical in this regard is
the viscosity, not the density. This can be assumed because the amount of mass in this system is
so miniscule that the inertial forces involved to move the mass can be disregarded. This
assumption was affirmed by discussing the design with engineers working with the Molon
Motors Company. Based on this information, it can be assumed that the brown sugar will be the
most critical part of the dispensing design. This assumption has been made based on the fact that
all of the ingredients are dry and powder like with the exception of brown sugar which usually
has molasses or some other type of viscous syrup. This assumption was affirmed by talking with
a technical sales person with the Augers Unlimited Company.
Based on the information gathered by talking to representatives from Augers Unlimited
and Molon Motors, two screw designs could be implemented. This information is shown in
Table 2. These designs represent a rough range for the auger screw. Screw Design 1 being the
smallest and Screw Design 2 being the largest. Therefore, there is an expected volume range of
0.3 in3 to 14.5 in3 of material being pushed out by the screw at any given time.
18
Shake and Bake: Preliminary Design Report October 12, 2011
Table 2: Table for Imputing Possible Auger Screw Designs
Screw Design
:
Outer Dia. (In.)
Root Dia. (In.)
Thread width (In.)
Threads/In.
Exposure Length
(In.)
Barrel Length
(In.)
Material in Exposure
Region (In.^3)
Material in Barrel (In.^3)
Total Materal In Screw (In.^3)
1 1.00 0.50 0.18 3.00 3.00 3 0.1471 0.1471 0.29432 2.00 0.50 0.18 3.00 3.00 3 7.2157 7.2157 14.4315
Table 3 and Table 4 show the mass calculations for each ingredient. This table was
formulated using each ingredient density value from Table 1 along with the total mass in the
system calculated for Screw Design 1 and Screw Design from Table 2. Doing this for the two
assumed screw size ranges can give estimated value for the maximum mass that will be pushed
through the auger screw at any given time. The maximum mass found based on the rudimentary
designs is .6256 pounds for our critical ingredient, brown sugar. This is the load the screw will
have to constantly push at varied rates to output the critical ingredient. This information will help
determine a torque requirement for the motors.
Table 3: Mass Calculations for Screw Design 1:
Screw Design 1:
Mass in Exposure Region
(Lbs)
Mass in Barrel (Lbs)
Total Mass in Screw (Lbs)
flour 0.0032 0.0032 0.0063sugar 0.0045 0.0045 0.0090brown sugar 0.0038 0.0038 0.0077salt 0.0064 0.0064 0.0128baking powder 0.0038 0.0038 0.0077baking soda 0.0037 0.0037 0.0073
19
Shake and Bake: Preliminary Design Report October 12, 2011
Table 4: Mass Calculations for Screw Design 2:
Screw Design 2:
Mass in Exposure Region
(Lbs)
Mass in Barrel (Lbs)
Total Mass in Screw (Lbs)
flour 0.1546 0.1546 0.3092sugar 0.2213 0.2213 0.4426brown sugar 0.1880 0.1880 0.3759salt 0.3128 0.3128 0.6256baking powder 0.1880 0.1880 0.3759baking soda 0.1796 0.1796 0.3592
20
Shake and Bake: Preliminary Design Report October 12, 2011
Motors and Gearing
Because significant friction occurs between the screw and material, the screw and
housing, and the material itself, an exact value for the torque required from the motor is difficult
to calculate. A model needs to be constructed and tested to incorporate friction values into
torque requirements. To acquire the torque requirement for the motors, various auger companies
and motor companies were consulted based on the project scope. These companies concluded
that several motors are capable of driving this dispensing system. They also concluded that there
are several motors that meet the specifications and fit the budget. One engineer from Molon that
was consulted estimated that the necessary torque would be between 2 and 5 inch pounds of
torques. From a table found on the internet, 557.6 in*lbs of torque is roughly one N*m.
Therefore, the metric torque requirement should not exceed 0.009 N*m of motor torque. The
current dispensing motors selected provide .3 N*m at 60 rpm. Because the torque supplied by
the motors is significantly higher than the torque requirements, the motor may be geared to
decrease torque and increase rpm to ensure that one cup of ingredient is dispensed in 75 seconds.
The flow rate required to achieve this dispensing time is 3.15 cm3/second. Using Screw Design
1, which outputs 8.576 cm3/rev, the minimum required rotational speed is 22.0 rpm for 75
seconds.
21
Shake and Bake: Preliminary Design Report October 12, 2011
Program Design
In Figure 6, shown on the following page, the preliminary program is outlined with a
flow chart. This flow chart is a basic representation of how the device will operate. The program
will take multiple complex algorithms working together in order to produce the desired final
operation of the device. The basic functions within our flow chart incorporate:
The input of the user from the home screen
Checking to see if the contents of the containers have enough ingredients to dispense
the recipe entered
Give the user an option to save the recipe entered
Prompt the user to dispense when ready
22
Shake and Bake: Preliminary Design Report October 12, 2011
Figure 6: Basic Overall Flow Chart Design for Program
23
Shake and Bake: Preliminary Design Report October 12, 2011
Organization and Management
Team Shake and Bake consists of three mechanical engineering students, one electrical
engineering student, and one computer engineering student. The tasks will be assigned to project
members as follows:
Andrew Townsend - mechanical engineer
Andrew is the team leader, responsible for coordinating group meetings and
consolidating written reports. He is the primary engineer designing the dispensing mechanism
and choosing the motors and gearing that will be used to power this mechanism.
Ryan Johnson - mechanical engineer
Ryan is responsible for implementing the scales into the dispenser design. It is his job to
choose which sensors to use, where they will be placed, and how they will be configured. He is
also overseeing the structural design of the control unit, which will house many of the electrical
components, including the user interface and microprocessor.
Kara Tobey - mechanical engineer
Kara is the engineer designing the six bases and containers. She will address issue
regarding materials, configuration, connections between bases and containers, connections
between the different bases, and interfacing with the dispensing unit and sensors.
Aldo Campos - computer engineer
Aldo is in charge of selecting the microprocessor for the project and any additional
memory that is needed. He will be the primary engineer responsible for programming the
microprocessor to perform its various functions.
Grant Arthur - electrical engineer
25
Shake and Bake: Preliminary Design Report October 12, 2011
Grant is designing and implementing the electrical components for this project. It is his
job to select the power supply, keypad, scanner, and LCD screen that will be used and to design
the circuit board. Grant is also in charge of keeping track of the budget and expenses.
Budget
Part Description Quantity Price
per
Unit
Tax and
shipping
Price
Total
Vendor
DC Motors Jammeco 38GM-253500 6 $15.95 $7.00 $102.70 jameco.com
Force Sensors Interlink Electronics
Standard 402 FSR
32 $6.44 $2.56 $208.64 DigiKey.com
Microprocessor DSPIC30F6015 2 $9.94 $0.00 $19.88 Newark.com
Barcode
Scanner
Adesso NuScan 3200
Optical Laser USB
Barcode Scanner
1 $111.95 $9.90 $121.85 bhphotovideo.com
Extrusion
Screw
6 $0.00 $0.00 3-D Printer
LCD Screen LCD DISP TFT 3.5"
320X240 B/L
1 $28.50 $6.24 $34.74 DigiKey.com
Power Supply Power One BLP55-3300 1 $44.51 $7.00 $51.51 Onlinecomponents.com
Gears $0.00 3-D Printer
PCB Board Professional Circuit Board 1 $51.00 $0.00 $51.00 expresspcb.com
Miscellaneous
Electronics
1 $50.00 $50.00
Keypad KEYPAD 12 KEY
FRONT PANEL MNT
1 $13.52 $2.56 $16.08 DigiKey.com
Material 1 $100.00 $100.00
Container
Material
DURAPLEX 2' x 4' Clear
Acrylic Sheet
1 $26.98 $1.89 $28.87 Lowe's
26
Shake and Bake: Preliminary Design Report October 12, 2011
Miscellaneous
Shipping
$20.00 $20.00
Total $57.15 $805.27
27
Shake and Bake: Preliminary Design Report October 12, 2011
Gantt Chart Spring 2012
Pert Chart Fall 2011
Pert Chart Spring 2012
Work Breakdown Structure Fall 2011
ID Task Description Deliverables Duration (Days)
People* Resources
O1.0 Project Management
Ensure that the project is on schedule and on budget
Specifications met in a timely manner
80 Andrew PC
O2.0 Documentation Keep records of design decisions, research, and tests
Engineering notebooks and A-3 reports
80 A, Al, G, K, R PC, Notebooks
F1.0 Project Selection Select a project A verbal decision 12 A, Al, G, K, R NotebooksF2.0 Requirement
SpecificationsTechnical Description of project goals
Document 16 A, Al, G, K, R PC
F3.0 System Design and Project Plan
Description of systems operation, project plan, and budget
Document 9 A, Al, G, K, R PC
F4.0 System Layout Develop a plan for device operation and functionality
Notebook documentation
11 A,Al, G, K, R Notebooks
F5.0 Device Design Design the device Detailed design of all components
47 A, Al, G, K, R PC
F6.0 Sensor Placement Select appropriate force sensors. Design appropriate electrical interface and placement
Detailed design, Schematics
7 Ryan PC
F7.0 Dispensing Mechanism Design
Design the extrusion method and motor system
Detailed design, Solidworks drawing
14 Andrew PC
31
Shake and Bake: Preliminary Design Report October 12, 2011
F8.0 User Interface Select the appropriate LCD and bar code scanner. Design appropriate electrical interface
Detailed design, Schematics
20 Grant PC
F9.0 Microprocessor Interface
Microprocessor to operate all components
Detailed design 20 Aldo PC
F10.0
Container Housing Design
Design a housing for the motors and scales. Also holds the containers
Detailed design, Solidworks drawing
14 Kara PC
F11.0
Power Supply Selection
Select a suitable power supply
Specifications 3 Grant PC
F12.0
Container Design Design a sealable container that can house the dispensing mechanism
Detailed design, Solidworks drawing
18 Kara PC
F13.0
Electronic Housing Design
Design a housing for the microprocessor and electronics
Detailed design, Solidworks drawing
13 Ryan PC
F14.0
Interim Design Interim system and subsystem design
Document, Presentation
23 A, Al, G, K, R PC
*A = Andrew, Al = Aldo, G = Grant, K = Kara, R = Ryan
32
Shake and Bake: Preliminary Design Report October 12, 2011
Work Breakdown Structure Spring 2012
ID Task Description Deliverables Duration (days)
People* Resources
O1.0 Project Management
Ensure that the project is on schedule and on budget
Specifications met in a timely manner
79 Andrew PC
O2.0 Project Documentation
Keep records of design decisions, research, and tests
Engineering notebooks and A-3 reports
79 A, Al, G, K, R
PC, Notebooks
S1.0 Device Build Assemble of all the device components
Assembled components
38 A, Al, G, K, R
Workshop, PC
S2.0 Dispensing Mechanism Build
Build the dispensing mechanism used in our device
Assembled components
23 Andrew Work Shop
S3.0 Microprocessor Programming
Write the code for the microprocessor and download to device
A programmed and functional microprocessor
23 Aldo PC, Evaluation
board, Oscilloscope
S4.0 Sensor Build Build the platform on which the sensors rest and install sensors
Assembled components
23 Ryan Workshop
S5.0 User Interface Build
Build the components that will communicate with the user
Assembled components
23 Grant PC, Evaluation
board, Oscilloscope
S6.0 Container Build Build the containers, which will hold the ingredients
Assembled components
11 Kara Work Shop
S7.0 Container Housing Build
Build the housing for the containers
Assembled components
13 Kara Work Shop
S8.0 Container Testing
Perform a test on the containers to make sure it can hold a standardized bag, and also keep the ingredients fresh
Working components, that meet the specifications documented
14 Kara Workshop
33
Shake and Bake: Preliminary Design Report October 12, 2011
S9.0 Container Housing Testing
Make sure the container attaches to it, and it can also hold the containers full of each ingredient
Working components, that meet the specifications documented
14 Kara Workshop
S10.0 Electronic Housing Build
Assemble all the electric components
Assembled components
11 Ryan Workshop
S11.0 Sensor Testing Test the sensors to ensure that they are registering the correct force and communicating to the microprocessor
Working components, that meet the specifications documented
11 Ryan Workshop
S12.0 Power Supply Testing
Test with different loads, the ripple, 30 Ω resistor, and with a oscilloscope to test the ripple
Working components, that meet the specifications documented
6 Grant Workshop
S13.0 Dispensing Mechanism Testing
Perform a test on the dispensing mechanism to ensure that it dispenses within the documented error
Working components, that meet the specifications documented
13 Andrew Workshop
S14.0 User Interface Testing
Perform a test within the components communicating with the user to make sure it is outputting the right things, and also receiving the right input
Working components, that meet the specifications documented
11 Grant PC, Evaluation
board, Oscilloscope
S15.0 Microprocessor Testing
Verify that the microprocessor is operating as desired
Functional microprocessor operating as desired
11 Aldo PC, Evaluation
board, Oscilloscope
S16.0 Electronic Housing Testing
Test all the output and input of the electric components
Working components, that meet the specifications documented
6 Ryan Workshop
34
Shake and Bake: Preliminary Design Report October 12, 2011
S17.0 System Integration
Combine all the components
Complete System
19 A, Al, G, K, R
Workshop
S18.0 System Testing Test system for technical specifications; modify what is needed
Fully functioning prototype
18 A, Al, G, K, R
PC, Evaluation
board, Oscilloscope
S19.0 User’s Manual Describes how to use the device along with any special considerations
Document 11 A, Al, G, K, R
PC
S20.0 Final Report Final report about the prototype
Document 13 A, Al, G, K, R
PC
*A = Andrew, Al = Aldo, G = Grant, K = Kara, R = Ryan
35
Shake and Bake: Preliminary Design Report October 12, 2011
Appendix A:
Technical Requirement Specifications
Overview: 36
Shake and Bake: Preliminary Design Report October 12, 2011
Fresh-baked cookies, banana bread, and hot biscuits are integral to American culture. Hundreds of such deserts, breads and pastries are made by household cooks every year, from small children standing on chairs to the moms who help them stir to great-grandmothers who have prepared such treats for several generations. Small-scale baking is a ubiquitous activity which captures the attention of many. Every local coffee shop hides someone whipping up a batch of blueberry scones in the back, and many small restaurants offer their own homemade desserts.
The system of measuring out ingredients for such projects is a standard process that has remained steadfast for generations. The process is simple, but time-consuming and messy. Frequently, ingredients are spilled onto the countertop or floor during measuring. If a scoop needs to be reused, it must be washed first in order to avoid contamination and all measuring utensils must be washed again at the end of the process. The cleaning up that is necessary due to these factors is generally detested by bakers, who would rather spend their time on other activities. Also, accuracy is sacrificed when the baker is in a hurry and doesn’t have time for exact measurements; time is sacrificed when the baker slows down to focus on accuracy.
We believe that baking can be simplified with new technology, as so many other areas of life have been. There’s no need to keep using the same old process when the cookies can taste just as good and take less time!
Our ingredient dispenser measures out dry ingredients common to baking in increments specified by the user. The machine’s functions greatly simplify the common but inefficient process that includes opening containers, retrieving measuring utensils, measuring out ingredients, cleaning up spills, closing containers, and washing utensils.
Benefits of this product are numerous. In addition to dispensing accurate quantities in a timely manner, it stores the ingredients and keeps them fresh, dry and clean. It eliminates spills, the need to search for and wash measuring cups and spoons, and the headache of maneuvering many different containers. Also, the device can store previously used recipes and doesn’t forget how many cups it has measured already, as cooks are notorious for doing. The ingredient dispenser generally creates a cleaner, more efficient baking environment.
Problem Statement:
37
Shake and Bake: Preliminary Design Report October 12, 2011
The majority of household cooks and small-scale bakers spend hours meticulously measuring out ingredients by hand, using an assortment of cups, spoons, and scoops. This method is time-consuming, requires repeatedly washing measuring utensils, and is often inaccurate when performed by rushed or easily distracted cooks. This device can speed up and clean up the baking process in homes and small restaurants, allowing cooks to focus on other elements of their work, rather than fussing with measurements.
Customer Needs: Dispenses "quickly" Reasonable size/weight in order to be easily handled Digitally stores combinations of ingredient measurements for repeated use Measures and dispenses multiple baking ingredients Device separates different ingredients Containers hold entirety of a standard-sized package of ingredients Keeps ingredients dry and clean Containers can be easily refilled when empty Containers are easily cleaned Not too "noisy" Notified when ingredient containers need to be refilled Measures contents in various units commonly used in baking Can customize recipes for various batch sizes Measures the amount of an ingredient(s) in response to user input Measures ingredients accurately
User Manual Rough Draft:
38
Shake and Bake: Preliminary Design Report October 12, 2011
The ingredient dispenser is simple to setup and operate. The user needs only to fill the containers with the appropriate ingredients, and then enter the desired amounts of ingredients or a recipe code via the user interface. Finally, insert a bowl and manually activate the dispensing mechanism, and the process is complete!
1. Remove the device from storage.
2. Connect to the desired power source.
3. Power on the device.
4. Fill empty containers.
5. Allow machine to calibrate.
6. Input the recipe or ingredients to be used and the desired amounts.
7. Place bowl underneath dispenser.
8. Activate dispensing mechanism.
9. Repeat steps 7-8 until all desired ingredients have been dispensed.
10. Power off the device.
11. Store the device in desired location.
Technical Requirements Specification:
39
Shake and Bake: Preliminary Design Report October 12, 2011
1. The time required to dispense one cup of ingredient should not exceed 75 seconds. (This is the approximate time a user needs to retrieve a measuring device and ingredient, use measuring device, wash measuring device, and put away measuring device and ingredient.)
2. The mass of the empty device should not exceed 15 kg. (This is the weight of an average countertop microwave.)
3. The device dimensions should be no greater than 0.5 m wide by 1.0 m long.
4. The device should have the capability to store at least five recipes in memory.
5. The device should have the capacity to contain no less than six separate ingredients. (This accounts for the most common baking ingredients: flour, white sugar, brown sugar, salt, baking powder, baking soda.)
6. The device should have containers with volumes no less than 0.4 L and no greater than 4.1 L. (This is based on standard ingredient package sizes, plus 20% extra volume)
7. The containers should be sealable.
8. The containers should detach from the main device in under ten seconds by a user familiar with the user manual.
9. The containers should be made out of an FDA-approved material.
10. The device should not produce a noise exceeding 90 dB within 1 m of the device. (This is the volume level of a standard household blender.)
11. The device should communicate with the user with visual output.
12. The device should perform according to user input.
13. The device should dispense correct ingredients within ±5% of the user input.
40
Shake and Bake: Preliminary Design Report October 12, 2011
Met
ricDi
spen
sing
time
Wei
ght o
f Dev
iceDe
vice
Dim
ensio
nsM
emor
y Ca
pabi
lity
Num
ber o
f Ing
redi
ent C
onta
iner
sSi
ze o
f Ing
redi
ent C
onta
iner
sM
eans
of K
eepi
ng In
gred
ient
s Airti
ght
Tim
e to
Det
ach
Cont
aine
rsCo
mpo
sition
of C
onta
iner
sN
oise
Leve
lPr
ogra
m O
utpu
tU
ser I
nput
Mea
sure
men
t Acc
urac
y
NeedDispenses "quickly" *Reasonable size/weight in order to be easily handled * *Digitally stores combinations of ingredient measurements for repeated use *Measures and dispenses multiple baking ingredients *Device separates different ingredients *Containers hold entirety of a standard-sized package of ingredients *Keeps ingredients dry and clean *Containers can be easily refilled when empty * *Containers are easily cleaned * *Not too "noisy" *Notified when ingredient containers need to be refilled *Measures contents in various units commonly used in baking *Can customize recipes for various batch sizes *Measures the amount of an ingredient(s) in response to user input *Measures ingredients accurately *
Table 1: Matrix containing our customer needs and resulting metrics
Design Deliverables:1. A working automated ingredient dispenser.
41
Shake and Bake: Preliminary Design Report October 12, 2011
2. Comes with ingredient containers. Replacement containers can be purchased.
3. Baking ingredients will be supplied for testing purposes, but customers will be responsible for purchasing their own ingredients for home use of the device
a) System specifications
b) Budget
c) User manual
d) Final report, including detailed drawings, schematics, flow charts, code, and test results
Preliminary Test Plans:1. Dispensing Time
a. For flour, white sugar, brown sugar – User inputs 1 c of ingredient into device. Device is timed with a stopwatch from activation to completion of dispensing. Pass if this time is under 75 s for each ingredient.
b. For salt, baking soda, baking powder – User inputs 1 T of ingredient into device. Device is timed with a stopwatch from activation to completion of dispensing. Pass if this time is under 75 s for each ingredient.
2. Weight of device – Weigh empty device with a scale that is accurate to 0.5 kg. Pass if weight is less than 15 kg.
3. Device Dimensions – Measure length and width of device with a tape measure. Pass if length is 1.0 m or less and width is 0.5 m or less
4. Memory Capability – Use memory function to recall a recipe, then dispense each ingredient from the recipe into separate containers. Measure the amounts with standard measuring cups or spoons. Repeat test with four additional recipes. Pass if device completes task and ingredient amounts are accurate.
5. Number of Ingredient Containers – Pass if device contains six different containers for holding ingredients.
6. Size of Ingredient Containers – One container of each size is filled with water. Water is weighed with a digital scale. Pass if weight of water is between 0.4 and 4.1 kg. (Corresponds to 0.4 and 4.1 L of water)
7. Means of Keeping Ingredients Airtight – Submerge each sealed container in water for 10 s. Pass if all containers are able to keep out water.
42
Shake and Bake: Preliminary Design Report October 12, 2011
8. Time to Detach Containers – Three people who have read the user manual (not members of the Shake and Bake team) will detach all six containers from the device while being timed with a stopwatch. Users will then complete a survey about the understandability of the user manual and ease of use of the device. Pass if all three users complete the task in 60 seconds or less and select “agree” or “strongly agree” on the survey.
9. Composition of Containers – Pass if material used in containers is on FDA list of approved materials. If material from 3D printer is used in prototype, state in documentation that production units will be made of an FDA-approved material.
10. Noise Level – Measure the noise level (in dB) at a distance of 1 m from the device with a noise level meter. Pass if level is ≤ 90 dB.
11. Program Output – Pass if the device contains a component with visual output.
12. User Input and Measurement Accuracy – Input a measurement of 10 g of flour.
a. For flour, white sugar, brown sugar – Input a measurement of 10 g of flour. Dispense flour and weigh with a scale capable of measuring to the 0.5 g. Repeat experiment with measurements of 10 g, 50 g, 100g, and 150 g for each ingredient. Pass if all amounts are within 5% of the inputted amounts.
b. For salt, baking soda, baking powder – Input a measurement of 5 g of salt. Dispense flour and weigh with a digital scale capable of measuring to the 0.5 g. Repeat experiment with measurements of 5 g, 10 g, 25g, and 50 g for each ingredient. Pass if all amounts are within 5% of the inputted amounts.
Implementation Considerations:
43
Shake and Bake: Preliminary Design Report October 12, 2011
1. Ingredients must be restocked after repeated use. Device will notify user if there are not sufficient quantities to complete a function.
2. Containers designed to be periodically removed and cleaned manually.
3. Device designed to be self-calibrating.
4. Device to notify user if the proper ingredients are not in place.
Attachments:1. Patent Search: #5460209 – Applied in 1993 (See Appendix A)
Relevant Codes and Standards:
1. Sanitary Design and Construction of Food Equipment – University of Florida IFAS Extension (See Appendix B)
44