New Castle Design Associates Design Review of Insect Video Tracking Device April 23, 1999 Team 5 Sponsor: Keith Hopper, USDA & UD

The Staff Ryan S. McDonough Raymond M. Foulk IV Justin L. Combs George H. Sapna III

Background $100 million crop damage each year due to pests Introduction of beneficial (predatory) insects into environment Study of reproductive habits - Aphelinus asychis Want insect position as a function of time.

Problem Description Existing System: Measures insect movements within a small arena Specimens Camera Computer Problem: Confinement disturbs the behavior of the insects

Summary Mission: Our mission is to design, construct, and refine an insect video tracking system for agricultural research that provides our customers with a creative, realistic and performance-based solution. Approach: Our strategy will be to gain an overall knowledge of the project and then to strive for a solution by researching, benchmarking, and defining the customer’s wants and constraints. Finally, using an iterative design synthesis process, our team will generate the best solution to satisfy our customers.

CustomersWants Keith Hopperlarge area, position/speed, not disturb insect, track for 20 min., existing equipment, C++, minimize post pro., wireless device, interchange camera Mike Smith position/speed, minimize post pro, various conditions, reduce pesticides Richard Turcotteadaptable to other insects, not disturb insect, simple interface, large area, position/speed

Top 10 Wants Measure position and speed of the insect Track the insect over large area Adaptability to other types of insects Minimize post-processing of data Not to disturb the insect’s behavior Easy-to-learn user interface Ability to record for minutes Use existing equipment Benefits must outweigh costs Preferred language is C/C++

Constraints Project must be completed by May 1999 Project expenses must remain below $3500 Must cover a larger area than existing system Work area must occupy only Stearns Lab

Benchmarking Existing Video Tracking System Motion Control Systems Linear Motion Systems Motion Actuators Control Algorithms Image Processing

Position/speed X,Y coordinates of insects Instantaneous error Accumulation of error Maximum speed of motion Large areaSize of tracking area Adaptability to other insectsInsect size range Maximum speed of motion Minimize post-processingTotal acquisition time Frequency of acquisition Feedback delay Do not disturb insectDistance from device to insect Smoothness of surface Variation in luminance Wants Metrics

Simple user interface Desired programming language User friendly Record for min.Total acquisition time Frequency of acquisition Feedback delay Use existing equipmentAmount of existing equipment used Benefits outweigh costs Savings/Costs C/C++ Programming language Wants Metrics

Top Metrics & Target Values 1. Size of Tracking Area 1m x 1m 2. Distance from Device to Insect 0.5 m 3. X, Y Coordinates of Insect Yes 4. Accumulation of Error +/- 1mm 5. Instantaneous Error +/- 1mm 6. Savings/Costs 1 7. Maximum Speed of Motion 5 mm/sec 8. Frequency of Acquisition 1 Hz 9. Feedback Delay 0.5 sec 10. Variation in Luminance <5% 11. Total Acquisition Time 20 min 12. Programming Language C or C++

Concept Generation x y z F(s) TF(s) H(s) R C Cartesian Track Polar Track Sensing Surface Robot Wide Angle Pivot Moving Surface Bubble

Top Concepts 1. Cartesian Track 2. Mobile Robot 3. Wide Angle Camera 4. Existing system 5. Pivoting Camera 6. Polar track

Development Process How do we move the camera around to follow the insect? How do we recognize the insect from the camera? How do we tell the motion system to follow the insect? How do we get the position of the insect?

Development of the Motion System Geometry and Structure Footprint Area Beam Bending Torsional Deflection Camera Mounting Positional Requirements Rack and Pinion Design Requirements Motor Torque Requirements

Development of the Motion System Configuration: Two Trolleys, Rack and Pinion, & Stepper Motors

Development of the Motion System - X Trolley

Development of the Motion System - Y Trolley

Development of the Image Processing Algorithm Capture a Black and White Digital Picture The Insect Is Much Darker Than the Background Take the Derivative of the Image Isolate Pixels With Darkness Above A Threshold Average Pixel Array Coordinates to get the Center of the High Contrast Region

Taking the Derivative of an Image and Finding the Center

Development of the Motion Control Algorithm Keep the Bug in the Middle of the Screen Respond Proportionally to Bug Movements Avoid Unnecessary Movement

Motion Control Algorithm Speed and Acceleration Increase as the Bug Moves Away from the Center of the Action Circle Bug Must Walk Outside of Action Circle Sensitivity (Slope of Cone) Gain Distance from Center

Development of the Insect Position Algorithm Keep Track of Screen Coordinates of the Insect Keep Track of Base Frame Coordinates of the Camera Add the Positions Together Write the Absolute Position to a Data File

Insect Position Camera Screen Coordinates, [ x S y S ] Base Frame Coordinates, [ x B y B ] Insect Coordinates = [ (x B + x S ) (y B +y S ) ] Keep Track of Motor Rotations Keep Track of Pixel Location of Insect

Main Computer Image Analysis Motion Control Algorithm Stepper Controller Insect Position Calculator, Display, & Recorder Digital Camera X-Motor Y-Motors Motor Positions Integrated System Components

Prototype Costs Shop Fabrication:212.5 hours ($9585) Engineering Development:1100 hours ($11000) Assembly Time:25 hours ($250) Rack and Pinion Sets:$ Motors and Controllers:$ Stock Aluminum:$ Software:$ Other Parts:$ Shipping:$ TOTAL SPENT:$

5 Important Prototype Tests Metric #1: Size of Tracking Area (Target: 1m x 1m) Test #1: Measure Limits of Tracking Area Metric #2: Distance from Device to Insect (Target: 0.5 m) Test #2: Measure Distance From Bottom of Camera to Substrate Metric #3: X, Y Coordinates of Insect (Target: Yes) Test #3: Did the System Behave As Expected? Metric #4: Accumulation of Error (Target: +/- 1mm Test #4: Measure Distance Between Two Points Repeatedly Metric #5: Instantaneous Error (Target: +/- 1mm) Test #5: Measure Largest Static Amplitude

Test Results

Modifications To Original Design Added Limit Switches Added Shaft Support Bearings Added Cosmetic Features (wire clamps, etc.) Improved User Interface

Demonstration

Actual Data From An Insect

Recommendations For Improvement Use Servo Motors to Reduce Motor Vibrations Bolt Legs to Table Stiffen Legs to Reduce Frequency of Vibrations Replace Computer With Faster Model Create a Windows-Based Interface