Visual Target Tracking System

Final DesignFebruary 26, 2003

Chad Helm

Matthew Sked

James Deloge

Tim Bagnull

Objective

To track a moving point on a screen. This moving point will be simulated by a PowerPoint animation.

We assume this point will be traveling no faster than 300 mm/sec. (approx. 1 ft./sec.)

Initialize the system by using edge detection to locate the point.

Features

User Interface in C++ or Visual Basic System initialization (edge detection). Displays the target and tracking on-

screen. System reset and shutdown.

System Diagram

Camera

ARCS card

Pan TiltStages

Frame Grabber

CPU C++RS-232

Sim

ulin

k

motion

drivers

Specification

Top angular motion of 6 degrees/sec. for both axis.

For acceptable reliability the system must be no more than about 20 degrees off center of the screen.

Desired settling time of 0.1 seconds Desired overshoot of 1%

Preliminary Modeling

Investigated various starting positions and gains.

Did not vary different gears and motors. Used Pittman’s GM8724S010 motor.

1:1 gear ratio

Final Motors

Pan motor: GM8724S010 6.3 Motor Gear 1:1 Belt Drive

Tilt motor: PG6614 4:1 Motor Gear 2.7:1 Belt Gear 6-8 week lead time

Linear Simulation

Used Proposal gains in the linear model.

Added integral gain (Ki = 0.5). Used MATLAB rltool to find optimal

gain parameters.

Pan Root Locus

Observed the system settling time to be 0.5 seconds.

Unable to move all of poles to the constrained region.

Linear Step Response of Pan

Settling time at 0.1s, but 10% overshoot.

Controller Transfer Function

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505059.7

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Linear Pan Bode Plot

Tilt Root Locus

25% overshoot from our initial gains.

Pulled movable poles and zeros to fit in the constrained area.

Linear Step Response of Tilt

Settling time at 0.1s, negligible overshoot.

Tilt Transfer Function

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Linear Tilt Bode Plot

Linear Simulation Summary

Design Specifications of 0.1s settling is met for both stages.

1% overshoot is met only for tilt. Feasibility of root locus zero-pole

placements unclear. Unstable plant pole?

Non-Linear Simulation

Used the controller gains in the non-linear model.

Pan stage has considerable overshoot. Tilt stage has steady state error.

Non-Linear Screen Translation

Cost

Motors: $179.60 Pulleys: $36.50 Belts: $10.20

Total Parts Cost: 226.30 Four persons working 12 hours a week

for 15 weeks at $100/hour: $72,000

Task 2/10/03 2/17/03 2/24/03 3/3/03 3/10/03 3/17/03 3/24/03 3/31/03 4/7/03 4/14/03 4/21/03 4/28/03Final DesignConstructionProgrammingTestingARCS control softwareARCS DIO portsOrder PartsHook camera and operateTest camera with the roomCreate PPT animationEdge DetectorKalman FilterUser InterfaceRS-232 communicationsDesign ProposalProgress ReportFinal ReportFinal Design ReviewProject DemonstrationFinal Presentation

Computer Vision

Motion

Date

Documentation and

Presentations

Spring Break

Gantt Chart

Verification

Verification will be done on both of the subsystems independently before integration.

Pan-Tilt Small, discrete point to point movements.

Distance to be dictated by the Kalman filter. Computer Vision

Ensure the software can track a point in a sequence of frames.

Verify camera and frame grabber works with the software.

Problems with Verification

The element of our project that will likely present us with the most problems is image processing. We are currently unsure of the maximum frame rate we can use and still have the system behave properly.

The frame rate translates into elements like the speed at which the target object can move, and the distance at which the system is placed from the screen (which determines range and precision of motion).

Cost

Total Cost: $226.36 Pan Tilt System

Motor: $179.60 ($89.80 each) Pulleys: $36.56 ($9.14) Timing Belt: $10.20 ($5.10)

Computer Vision Provided by Ben and Prof. Wen (Free)

Camera, Frame Grabber, CPU (dedicated for vision processing)

Conclusion

We have confidence with our motor and gear specifications.

Our current uneasiness resides with our software.