Remote-Controlled “Pac-Man” Game

1. Remote-Controlled “Pac-Man” Game Timothy Sperr YuriyDragonuv Nathaniel Pearson

2. Agenda • Overview & System Diagram – Tim • Game Design – Tim • Vehicle – Tim • Construction – Nate • Image Processing – Yuriy • Multidisciplinary Aspects – Nate • Testing Strategy – Tim • Integration Strategy – Yuriy

3. Overview • Our goal: to design a system that is both entertaining and technically interesting • The solution: • A “robotic” Pac-Man game • Pac-Man is a player-controlled R/C vehicle • The maze is a real, physical object • The ghosts and items are software items projected down onto the maze • Image recognition is used to locate Pac-Man

4. Overview

5. Game Design The game: Pac-Man • Player’s character Pac-Man navigates a maze • The goal is to collect all the “pellets” in the maze while avoiding 4 AI ghosts • By eating “power pellets” Pac-Man powers up and can then chase & eat ghosts

6. Game Design • Our game will be implemented in Visual C# • It will be the same game, without a Pac-Man graphic • Software will operate on “time slices” • For each time slice, the game will find the Pac-Man vehicle, run game logic algorithms, and update object positions • DirectX and/or XNA game studio may be required

7. Game Design Performance considerations: • Certain in-game constants and variables are highly dependent on the vehicle’s performance (speed, turning, etc) • Each time slice must be processed fairly quickly (in 30 milliseconds or less) to ensure a decent framerate

8. Vehicle VSTank*R 1/48th scale R/C battle tank

9. Vehicle Size: • 2.75” by 1.75” • Game maze will be split into 10x12 grid of squares • Maze must be smaller than 8’ by 8’ • Thus, the vehicle must be smaller than 7” by 7” • Also, vehicle turning radius must be accounted for

10. Vehicle Speed & Maneuverability: • 3 tests were done on the vehicle to gauge performance • A straight-line speed test • A 360-degree turn test • A zig-zagging path test • Preliminary tests resulted in: • 0.77 feet per second • 0.4 seconds for a 90 degree turn

11. Vehicle Battery Life: • R/C vehicle does not use commerically-available batteries • Charges its internal battery using the remote control • Battery lifespan averages 2 minutes • Modifications are most likely going to be necessary to extend battery life

12. Construction • Mounting Structure • Box • Legs • Leg attachment assembly • Maze Mat • Floor • Walls

13. Mounting Structure • Box • Sides • Bottom • Ventilation

14. Mounting Structure • Legs • Diameter • Material

15. Mounting Structure • Leg attachment assembly • Hinge Joint • Adjustment

16. Maze Mat • Floor • Peg board division • Peg board coloring • Peg board connection • Walls • Pvc division • Dowel division • Dowel slotting • Pvc coloring

17. Image Processing • Objective: • Find Pac-Man’s position in the maze • Tools: • Logitech Quickcam Communicate MP • 960 x 720 “effective pixels” • AForge.NET • .NET Image capture and manipulation library

18. Image Processing • Aside: HSB color space http://en.wikipedia.org/wiki/File:HSV_cylinder.png http://en.wikipedia.org/wiki/File:Barns_grand_tetons_HSV_separation.jpg

19. Image Processing • Image Capture • Handled by AForge.NET. Just need to write event handler to receive video frames. • Processing for each frame • Median filter to filter noise • Conversion to HSB color space • Filter by hue, then run algorithm to find “blobs” • Filter by blob size • Should now have X and Y coordinate of Pac-Man’s position.

20. Image Processing • Coordinate conversion • Game software uses a 2-D array for the entire maze. • Linear scaling and offsets are planned to be used, but: • Perspective may cause issues. • Based on math, expect Pac-Man to take ~20-25 pixels on the captured frames, which is expected to be enough to find it.

21. Multi-Disciplinary • Hardware • Mechanical Engineering • Electrical Engineering • Civil/Structural Engineering • Computer Engineering • Software • Electrical Engineering • Computer Science

22. Testing Pre-Build Testing: • Vehicle performance • Projector angle • Webcam resolution & angle

23. Testing Software Testing: • Unit tests on individual components • Thorough test of game logic • Integration tests: • Game logic ↔ coordinate change algorithm • Game logic ↔ maze traversal algorithm • Coordinate change algorithm ↔ image recognition • Various tweaks to balance gameplay

24. Testing Post-Build Testing: • Lighting conditions test • Projector housing structural tests • Maze construction structural tests • Whole system integration tests

25. Integration • Integration of individual software components • Integration of projector/webcam with supporting mounting structure and maze • Integration of game software with projector display and webcam video capture.

26. Any Questions?