Group 1 Transmitter-Based Tracking Systemcats-fs.rpi.edu/~wenj/ECSE4962S04/final/team1finalpresentation.pdfSensors used for proximity Sensors used for proximity instead of triangulation

Group 1Group 1

TransmitterTransmitter--Based Tracking Based Tracking SystemSystem

Paul Allen Paul Allen Lloyd CamposagradoLloyd CamposagradoAndrew HeppAndrew HeppJoo Yun SonJoo Yun SonApril 21, 2004April 21, 2004Rensselaer Polytechnic Rensselaer Polytechnic InstituteInstitute

MOTIVATIONMOTIVATION

WHOWHO–– Sport RecreationSport Recreation–– Home SafetyHome Safety–– National SafetyNational Safety

WHYWHY–– Accurate tracking of a moving ballAccurate tracking of a moving ball–– To have a versatile tracking system using RF To have a versatile tracking system using RF

technologytechnology

PROJECT GOAL AND APPROACHPROJECT GOAL AND APPROACH

GOALGOAL–– To successfully build a pan and tilt mechanism that will track aTo successfully build a pan and tilt mechanism that will track an object n object

in 3D space using RF technologyin 3D space using RF technology

APPROACHAPPROACH–– Signal strength meters will receive a signal from a transmitterSignal strength meters will receive a signal from a transmitter–– Data from A/D converter will be filtered and convertedData from A/D converter will be filtered and converted–– The controller will accurately move the pan and tiltThe controller will accurately move the pan and tilt

OBJECTIVESOBJECTIVES

Proof of concept for a video tracking system using RF technologyProof of concept for a video tracking system using RF technology

Six signal strength meters, six amplifiers, one transmitterSix signal strength meters, six amplifiers, one transmitter

10’ x 10’ x 10’ 3D tracking space10’ x 10’ x 10’ 3D tracking space

Use data from signal strength meters to track the object in a smUse data from signal strength meters to track the object in a smooth ooth pattern.pattern.

Automatic cameras at a sporting event that can follow the ball Automatic cameras at a sporting event that can follow the ball smoothly without human interactionsmoothly without human interaction

DESIGN DESIGN STRATEGY

Design Specifications

DAS CONTROLLER

STRATEGYParameter Identification

Compensation

Dynamic model (Plant)

Order parts and build/test sensors and transmitter

Integration with MatLab using A/D converters

Generate distance profile

Build 3D space for testing

Mounting System

Controller Design

Integration

Simulation of data acquisition in MatLab

Preliminary design of signal processing

Forced to modify design to use disturbance field

Open loop verification

Non-linear simulation and Full Control Model

Closed loop verification and Tuning

Rise Time: <0.1 secondsRise Time: <0.1 secondsSettling Time: <0.5secondsSettling Time: <0.5secondsMaximum Percent Overshoot: < 10%Maximum Percent Overshoot: < 10%Torque Saturation: 0.71 NmTorque Saturation: 0.71 NmInternal Gear Ratio: 19.5Internal Gear Ratio: 19.5External Gear Ratio: 4External Gear Ratio: 4Friction IdentificationFriction IdentificationMax speed of ball: 10 ft/sec => 5 rad/secMax speed of ball: 10 ft/sec => 5 rad/secPan Range of: 140 degreesPan Range of: 140 degreesTilt Range of: 130 degreesTilt Range of: 130 degreesCamera Height ~ 3.8ftCamera Height ~ 3.8ftCamera Distance from outer edge of Area Camera Distance from outer edge of Area of Interest ~ 2ftof Interest ~ 2ft


DAS CONTROLLER

Parameter Identification

Compensation






Mounting System

Controller Design

Integration











The signal plots to the right show the The signal plots to the right show the three strongest signals from the six three strongest signals from the six signal strength meterssignal strength meters


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration







Design SpecificationsIntegrationIntegration–– Connect each sensor to A/D Connect each sensor to A/D

converter via parallel cableconverter via parallel cable–– A/D converter replaces volt A/D converter replaces volt

metermeter

3D space3D space–– Dimensions reduced to 8’ x 8’ x Dimensions reduced to 8’ x 8’ x

8’ due to space constraints8’ due to space constraints–– PVC pipe used for support and PVC pipe used for support and

concealment of wire concealment of wire connectionsconnections

ObstaclesObstacles–– Power supply ground wire Power supply ground wire

acted as an antennaacted as an antenna–– Batteries lose power quickly for Batteries lose power quickly for

any type of reliabilityany type of reliability–– Inconsistent parts created Inconsistent parts created

different signal readingsdifferent signal readings

SolutionsSolutions–– Further reduced dimensions to Further reduced dimensions to

a 2D 8’ x 4’ rectangle (YZ a 2D 8’ x 4’ rectangle (YZ plane)

DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration







plane)


DAS CONTROLLERSplit distance profile at max and min Split distance profile at max and min to ensure 5 sections of nonto ensure 5 sections of non--repeating repeating valuesvalues

Used velocity direction to identify up Used velocity direction to identify up coming sectioncoming section

Not successful due to change in Not successful due to change in distance profile with reflections and distance profile with reflections and diminishing battery powerdiminishing battery power


Compensation






Mounting System

Controller Design

Integration








DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration



Sensors used for proximity Sensors used for proximity instead of triangulationinstead of triangulation

The threshold voltage is set to The threshold voltage is set to represent a close proximity for represent a close proximity for each sensoreach sensor

YZ coordinates are associated YZ coordinates are associated with each sensor in the 2D planewith each sensor in the 2D plane

When the proximity field is When the proximity field is disturbed, the output of the DAS disturbed, the output of the DAS are the coordinates of the are the coordinates of the corresponding sensor.





corresponding sensor.


DAS CONTROLLER

Fixture Mass = 0.029kgFixture Mass = 0.029kgCamera Mass = 0.144kgCamera Mass = 0.144kgMounting Bracket Mounting Bracket -- ABS plastic


Compensation






Mounting System

Controller Design

Integration



ABS plastic





Tilt Payload


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration



Tilt Motor Tilt Motor –– Coulomb FrictionCoulomb Friction–– Viscous FrictionViscous Friction–– InertiaInertia

Pan MotorPan Motor–– Coulomb FrictionCoulomb Friction–– Viscous FrictionViscous Friction–– Inertia



Inertia




Pan Motor Pan Motor –– Coulomb FrictionCoulomb Friction

Positive: 1.9594 VPositive: 1.9594 VNegative: 1.9594 VNegative: 1.9594 V

–– Viscous Friction: 0.0342 VS/radViscous Friction: 0.0342 VS/rad–– Internal Inertia: 9.2 eInternal Inertia: 9.2 e--7 Kg*m^27 Kg*m^2

Tilt MotorTilt Motor–– Coulomb FrictionCoulomb Friction

Positive: 1.3999 VoltsPositive: 1.3999 VoltsNegative: 1.3261 VoltsNegative: 1.3261 Volts

–– Viscous Friction: 0.0285 VS/radViscous Friction: 0.0285 VS/rad–– Internal Inertia: 9.2 eInternal Inertia: 9.2 e--7 Kg*m^27 Kg*m^2

(Coulomb Frictions converted to torque using (Coulomb Frictions converted to torque using K*Nm*A/V)K*Nm*A/V)

Tilt payload (Camera + mount + shaft)Tilt payload (Camera + mount + shaft)–– Mass: 0.3571 KgMass: 0.3571 Kg–– Inertia matrix identifiedInertia matrix identified

Mounting Bracket determined Mounting Bracket determined using CADusing CADShaft CAD was provided in Shaft CAD was provided in classclassCamera was represented Camera was represented using a spherical modelusing a spherical model

–– Center of mass (m): [0 0.0152 Center of mass (m): [0 0.0152 0.0220]0.0220]


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration





Basic Equation for Pan and Tilt as Basic Equation for Pan and Tilt as represented in a simulink diagram Non-linear simulation and

Full Control Model


represented in a simulink diagram


Gain MarginGain Margin–– InfiniteInfinite

Phase MarginPhase Margin–– 8.31 deg at 11.8 8.31 deg at 11.8

rad/secrad/sec


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration







To Verify Open loop modelTo Verify Open loop model–– Using a determined input Using a determined input

torque, verify that the simulated torque, verify that the simulated response matches the actual response matches the actual response using constant inputs response using constant inputs and changing inputsand changing inputs


Sine Function Ramp Function


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration








DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration



For Tilt motor, treat gravity as a For Tilt motor, treat gravity as a disturbancedisturbanceG(s) = k/(sG(s) = k/(s22 + as)+ as)





Linear Plant Model

Controller Design

Based on the desired performance specs, Based on the desired performance specs, the controller parameters can be identifiedthe controller parameters can be identified

–– Natural Frequency Natural Frequency -- WnWn–– Damping ratio Damping ratio -- ZZ

Determine the Determine the KKpp and and KKdd for each controllerfor each controllerSystem is designed to track (it will never System is designed to track (it will never reach steady state), so reach steady state), so KiKi is not necessary is not necessary

Get limits for Get limits for wnwn and zeta on root locus and zeta on root locus diagramdiagram


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration





Full Control model includes Full Control model includes Friction and Gravity Friction and Gravity CompensationCompensation

Closed loop modelClosed loop model




ClosedClosed--loop verificationloop verification–– Since we are tracking, all we are worried about is Since we are tracking, all we are worried about is

tracking a moving objecttracking a moving object–– Tracking an object at constant speed which Tracking an object at constant speed which

does not change directiondoes not change direction–– Tracking an object which changes directionTracking an object which changes direction


DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration



ClosedClosed--loop verificationloop verification–– Since we are tracking, all we are Since we are tracking, all we are

worried about is tracking a moving worried about is tracking a moving objectobject

–– Tracking an object at constant Tracking an object at constant speed which does not change speed which does not change directiondirection

–– Tracking an object which changes Tracking an object which changes directiondirection

TuningTuning–– In order to compensate for real world In order to compensate for real world

dynamics of the Pan and Tilt, we must dynamics of the Pan and Tilt, we must tune the designed controllertune the designed controller

–– This accounts for inaccurate frictional and This accounts for inaccurate frictional and gravitational models



gravitational models




DAS CONTROLLER


Compensation






Mounting System

Controller Design

Integration



The output from the DAS will define The output from the DAS will define the current location of the object in the current location of the object in 33--dimensional Cartesian coordinate dimensional Cartesian coordinate systemsystem

X direction fixed at 0 to X direction fixed at 0 to accommodate problems with accommodate problems with sensors (2D YZ space)sensors (2D YZ space)

The location of the camera can be The location of the camera can be changed dynamicallychanged dynamically

Based on the camera location, the Based on the camera location, the Simulink code will determine the Simulink code will determine the desired anglesdesired angles

3D tracking was tested with 3D tracking was tested with simulation only





simulation only

Integration

Simulation was run and Simulation was run and a 3D linea 3D line--ofof--best fit was best fit was extrapolated from the extrapolated from the data pointsdata points

Variations from the line Variations from the line of curve due to simulated of curve due to simulated noise and triangulation noise and triangulation inaccuraciesinaccuracies

RESULTSRESULTSDESIREDDESIRED

–– Max Speed 10 ft/secMax Speed 10 ft/sec–– Tracking error of 10% ~ 14 Tracking error of 10% ~ 14

degreesdegrees–– Rise time < 0.1 secRise time < 0.1 sec–– Setting Time < 0.5 sec

ACTUALACTUAL–– Max Speed ~ 20 ft/secMax Speed ~ 20 ft/sec–– Tracking error under 5%Tracking error under 5%–– Rise Time ~ 0.063 sec (step Rise Time ~ 0.063 sec (step

response)response)–– Settling Time ~ 0.309 sec Settling Time ~ 0.309 sec

(step response)(step response)Setting Time < 0.5 sec

Using sensors as proximity Using sensors as proximity Camera view Camera view Simulated Movement Simulated Movement

PROJECT ASSESSMENTPROJECT ASSESSMENT

ObjectiveObjective–– RF technology usedRF technology used–– Use six sensors to Use six sensors to

triangulate an objecttriangulate an object–– Smoothly track an Smoothly track an

object in a provided 3D object in a provided 3D space

AssessmentAssessment–– Low cost RF technology Low cost RF technology

is too unpredictable for is too unpredictable for tracking purposestracking purposes

–– Use five sensors to Use five sensors to signal object locationsignal object location

–– Sensors used for Sensors used for proximity in 2D spaceproximity in 2D space

space

CONCLUSIONCONCLUSION

Low cost RF technology is too unpredictable for tracking Low cost RF technology is too unpredictable for tracking purposespurposes–– Signal Strength Meter component variance is too greatSignal Strength Meter component variance is too great–– Reflection are too unpredictableReflection are too unpredictable

RF adequate for proximity detection and field RF adequate for proximity detection and field disturbancedisturbance

Controller designed works well for tracking but was not Controller designed works well for tracking but was not designed with steady state error as a specification so designed with steady state error as a specification so slight jitters occurred during proximity experimentsslight jitters occurred during proximity experiments

QUESTIONS?QUESTIONS?

Documents

Group 1 Transmitter-Based Tracking Systemcats-fs.rpi.edu/~wenj/ECSE4962S04/final/team1finalpresentation.pdfSensors used for proximity Sensors used for proximity instead of triangulation