ME 224-Final Project Jim Lovsin Erica Morales Dan Sheehan Josh Widzer.
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Transcript of ME 224-Final Project Jim Lovsin Erica Morales Dan Sheehan Josh Widzer.
ME 224-Final Project ME 224-Final Project
Jim Lovsin Jim Lovsin Erica Morales Erica Morales Dan Sheehan Dan Sheehan Josh WidzerJosh Widzer
OverviewOverview
IntroductionIntroduction Robot ActivitiesRobot Activities Gyroscope ActivitiesGyroscope Activities Path ProgrammingPath Programming ResultsResults Future WorkFuture Work ConclusionConclusion
ObjectivesObjectives
To design and implement an To design and implement an experiment to realize the control experiment to realize the control of a commercially available robotof a commercially available robot
To enhance our knowledge of To enhance our knowledge of LabView, data acquisition, LabView, data acquisition, feedback control, and MEMS feedback control, and MEMS sensingsensing
The GoalThe Goal
To create a robot which utilizes To create a robot which utilizes gyroscopic feedback control to navigate gyroscopic feedback control to navigate the predetermined path shown below.the predetermined path shown below.
3
6
45
90°
36.9°
53.1°
The EquipmentThe Equipment
A computer with LabVIEW and a A computer with LabVIEW and a data acquisition carddata acquisition card
A gyroscope sensor A gyroscope sensor (ADXRS150EB) from Analog (ADXRS150EB) from Analog DevicesDevices
A Boe-Bot Robot Kit (A Boe-Bot Robot Kit (www.parallax.comwww.parallax.com, #28132), #28132)
Robot ActivitiesRobot Activities
Servo CenteringServo Centering
AssemblyAssembly
Basic PathsBasic Paths
Servo CenteringServo Centering
Since the servos are not preadjusted in Since the servos are not preadjusted in the factory, it is necessary to adjust the factory, it is necessary to adjust the servos so that they are stopped the servos so that they are stopped when a 1.5 ms pulse is usedwhen a 1.5 ms pulse is used
AssemblyAssembly
The Boe-Bot came unassembled so The Boe-Bot came unassembled so some assembly was requiredsome assembly was required
Followed the instructions providedFollowed the instructions provided
Basic PathsBasic Paths
ForwardForward– Both wheels rotating in the same direction at the Both wheels rotating in the same direction at the
same speedsame speed
Right turnRight turn– Both wheels rotating at the same speed but the left Both wheels rotating at the same speed but the left
wheel goes forward and the right wheel goes wheel goes forward and the right wheel goes backwardbackward
Left turnLeft turn– Both wheels rotating at the same speed but the right Both wheels rotating at the same speed but the right
wheel goes forward and the left wheel goes wheel goes forward and the left wheel goes backwardbackward
Gyroscope FamiliarityGyroscope Familiarity
Operating Principles Operating Principles – Coriolis Acceleration Coriolis Acceleration
Fc = 2mv x Fc = 2mv x ΩΩ Capacitive SensingCapacitive Sensing
Self-Test Self-Test Calibration Calibration
– First Attempt First Attempt – Second AttemptSecond Attempt
Ref: K. Elliot, P. Gupta, K. Reed, and R. Rodriguez “Micromachined Vibrating Gyroscopes: Design and Fabrication” (2002) Northwestern University Mechanical Engineering 381: Introduction to Microelectromechanical Systems Final Project
Vibrating MEMS Gyroscope
Self-TestSelf-Test
Followed Self-Test Followed Self-Test Procedure from Chip Procedure from Chip Data Sheet Data Sheet
Power supply, Power supply, Multimeter, and Multimeter, and OscilloscopeOscilloscope– RATEOUT Initially 2.5 V RATEOUT Initially 2.5 V – Applied 4.6 V to pin 10. Applied 4.6 V to pin 10.
RATEOUT 3.2 V RATEOUT 3.2 V – Applied 4.6 V to pin 11. Applied 4.6 V to pin 11.
RATEOUT 1.81 VRATEOUT 1.81 VSatisfactory Self-Test
Schematic of ADXRS150EB
Ref: Analog Devices, ±1500/s Single Chip Yaw Rate Gyro with Signal Conditioning, ADXRS150EB Data Sheet http://www.analog.com/UploadedFiles/Data_Sheets/778386516ADXRS150 B.pdf
CalibrationCalibration
First Attempt First Attempt – Correlate Angle to Correlate Angle to
Voltage Signal Voltage Signal Second Attempt Second Attempt
– Correlate Angular Correlate Angular Rate to Voltage Rate to Voltage Signal Signal
LabVIEW to acquire LabVIEW to acquire and collect the data and collect the data
Excel to analyze the Excel to analyze the data data Block Diagram of LabVIEW
Calibration Program
Calibration First AttemptCalibration First AttemptCorrelate Angle to VoltageCorrelate Angle to Voltage
Θi = B0 + B1 Σ Vi Δt Θi = B0 + B1 Σ Vi Δt
Where: B0 and B1 are Where: B0 and B1 are parameters from OLS parameters from OLS
Experiment:
Turned Boe-Bot by hand to a known angle for a given time
Angles
•90 and 180 (deg)
Problems
•Accurate Positioning and Timing
•Numerical Integration
Theta versus integral of dV
y = -0.0028x + 161.61
R2 = 0.042
0
20
40
60
80
100
120
140
160
180
200
0 2000 4000 6000 8000 10000 12000 14000
integral of dV (deg)
an
gle
(d
eg
)
R2 = 0.04
Calibration Second Calibration Second AttemptAttempt
Correlate Angular Rate to Correlate Angular Rate to
Voltage d/dt (Θi) = B0 + B1ViVoltage d/dt (Θi) = B0 + B1Vi Where: B0 and B1 are Where: B0 and B1 are
parameters from OLSparameters from OLS
Experiment:
Turned Boe-Bot at a known angular rate for a given time
Angular Rate
•2.06, 3.05, 1.78 (rad/s)
Problems
•Accurate Positioning and Timing
•Numerical Integration
Theta versus integral of dV
y = -0.0028x + 161.61
R2 = 0.042
0
20
40
60
80
100
120
140
160
180
200
0 2000 4000 6000 8000 10000 12000 14000
integral of dV (deg)
an
gle
(d
eg
)
R2 = 0.64
Path following Path following programsprograms Basic Stamp ProgramBasic Stamp Program
– Directly creates the PWM signal Directly creates the PWM signal needed for the servosneeded for the servos
LabView ProgramLabView Program– Reads & analyzes readings from Reads & analyzes readings from
gyroscope, controls basic stamp gyroscope, controls basic stamp programprogram
Basic Stamp ProgramBasic Stamp Program' Robotics with the Boe-Bot - PathProgram.bs2' Robotics with the Boe-Bot - PathProgram.bs2' Closed loop path control for the Boe-Bot.' Closed loop path control for the Boe-Bot.' {$STAMP BS2} ' Stamp directive.' {$STAMP BS2} ' Stamp directive.' {$PBASIC 2.5} ' PBASIC directive.' {$PBASIC 2.5} ' PBASIC directive.DEBUG "Program Running!"DEBUG "Program Running!"'-----------------[Variables]--------------------'-----------------[Variables]--------------------INPUT 0INPUT 0INPUT 1INPUT 1INPUT 2INPUT 2INPUT 3INPUT 3DODOMain:Main: IF ( IN0 = 1 ) THEN StoIF ( IN0 = 1 ) THEN Sto IF ( IN1 = 1 ) THEN ForwardIF ( IN1 = 1 ) THEN Forward IF ( IN2 = 1 ) THEN RightIF ( IN2 = 1 ) THEN Right IF ( IN3 = 1 ) THEN LeftIF ( IN3 = 1 ) THEN LeftLOOPLOOPENDENDSto:Sto: PULSOUT 13, 750PULSOUT 13, 750 PULSOUT 12, 750PULSOUT 12, 750 PAUSE 18PAUSE 18 GOTO MainGOTO MainForward:Forward: IF ( IN2 = 1 ) THEN ForrightIF ( IN2 = 1 ) THEN Forright IF ( IN3 = 1 ) THEN ForleftIF ( IN3 = 1 ) THEN Forleft PULSOUT 13, 700PULSOUT 13, 700 PULSOUT 12, 800PULSOUT 12, 800 PAUSE 18PAUSE 18 GOTO MainGOTO Main
Main
Sto
Forward
Left
Right
Forleft
Forright
Forright: PULSOUT 13, 600 PULSOUT 12, 800 PAUSE 18 GOTO MainForleft: PULSOUT 13, 700 PULSOUT 12, 950 PAUSE 18 GOTO MainRight: PULSOUT 13, 775 PULSOUT 12, 775 PAUSE 18 GOTO MainLeft: PULSOUT 13, 725 PULSOUT 12, 725 PAUSE 18 GOTO Main
LabView ProgramLabView Program
2
1
3
4
5
67
89
9053.1
36.9
143.1
180There are three types of steps:
•Stopped (0,9)
•Straight line (1,3,5,7)
•Turning (2,4,6,8)
Nine total steps
LabView ProgramLabView ProgramFront Panel
Stop Step
LabView ProgramLabView ProgramTurning StepStep 8: 180 degrees CCW
LabView ProgramLabView ProgramStraight Path Step
Forright
Zero?No Yes
Greater than Zero?
No Yes
Forward
Forleft
Read AccumulatedVoltage
Path DemonstrationPath Demonstration
Reliability TestingReliability Testing
Performed ten trials to see Performed ten trials to see accuracy of Boe-Botaccuracy of Boe-Bot
Measured x and y distance from Measured x and y distance from starting point and endpointstarting point and endpoint
Recorded angles robot made Recorded angles robot made using LabVIEW using LabVIEW
Results of Reliability Results of Reliability TestingTesting
X Error (mm) Y Error (mm) Theta Error (deg)
Average 20.1 17.5 3.15
Standard Error 7.680422442 10.84486566 1.901023116
Desired Angle (degrees)
90 143.1 -53.1 -180
Average Value
(degrees
90.568 143.727 -53.702 -180.581
Standard Deviation
0.422027 0.357026 0.281772 0.256361
Deviation from Starting Point:
Angle Results:
Future Works Future Works
Create large deviation correction Create large deviation correction functionality.functionality.
Closed loop control of distance.Closed loop control of distance.– Use encoders on servo wheels.Use encoders on servo wheels.
Use LabVIEW Realtime to improve Use LabVIEW Realtime to improve performance over Windows.performance over Windows.
Use wireless 802.11g or bluetooth Use wireless 802.11g or bluetooth protocol to remove cable from system.protocol to remove cable from system.– Parallax has kits for sale.Parallax has kits for sale.
ConclusionConclusion
Successfully completed the task Successfully completed the task of programming the Boe-Bot to of programming the Boe-Bot to execute a pathexecute a path
Enhanced our knowledge of Enhanced our knowledge of LabVIEW, Basic Stamp, data LabVIEW, Basic Stamp, data acquisition, feedback control, and acquisition, feedback control, and MEMS sensing MEMS sensing
Questions?Questions?