EEL5666 Intelligent Machines Design Lab Tom and Jerry

EEL-5666 – Intelligent Machines Design Lab Tom and Jerry By: Nicholas Johnson & Joshua Hartman

Overview n n n n Overall Function Tom’s Design Jerry’s Design Special Sensor – RF Link Conclusions Possible Improvements Questions EEL-5666: Intelligent Machines Design Lab

Overall Function n n Jerry and Tom simulate a Predator / Prey Model. Jerry is the prey and has prey behaviors such as wandering and grazing. Tom is the predator and searches for Jerry. When Tom detects Jerry he will try to capture Jerry who tries to run away. EEL-5666: Intelligent Machines Design Lab

Tom EEL-5666: Intelligent Machines Design Lab

Platform n n n MAVRIC-IIB Development board Wood Cardboard part stands Black duct tape. More black duct tape. EEL-5666: Intelligent Machines Design Lab

Locomotion n GHM-03 Spur Gearhead Motor TPIC 0107 B-based motor driver These motors are fast EEL-5666: Intelligent Machines Design Lab

Obstacle Avoidance n n n 3 Devantech SRF 05 Use fuzzy-logic ideas to define obstacles as close, far, or in between Very rarely hit obstacles EEL-5666: Intelligent Machines Design Lab

Searching for Jerry n n Futaba S 148 Panasonic PNA 4611 Infrared Photo IC Servo rotates from -45 o, -22. 5 o, 0 o, 22. 5 o, 45 o At each location, reads A/D and detects if value<200. If so, Jerry is detected! EEL-5666: Intelligent Machines Design Lab

Searching for Jerry II n n IR detection not so easy: Must use ADC to read photo IC output Vout goes low upon detection Must have receiver highly shielded to give directional output EEL-5666: Intelligent Machines Design Lab

Jerry EEL-5666: Intelligent Machines Design Lab

Platform n Material: Wood ¡ n Small, Compact Design ¡ n Cut using the T-Tech Had to be smaller than Tom Limited Space ¡ ¡ Difficult to fit all the electronics Addition of unforeseen pieces problematic EEL-5666: Intelligent Machines Design Lab

Actuation n 2 Tamiya 70168 Double Gearboxes ¡ ¡ n n Driven by TPIC 0108 B PWM H-Bridge Wheels on either side function independently ¡ n 114. 7: 1 Gear Ratio 4 wheels total Each side driven by 1 Motor Driver Servo Motor to turn “Tom Detector” EEL-5666: Intelligent Machines Design Lab

Sensors n Bump Switches ¡ n Maxbotix Ultrasonic Rangers ¡ n n 2 Front, 2 Back 2 Front, 1 Back IR Emitter / Detector (Close Range) 56. 8 KHz IR Detector 315 MHz RF Receiver 434 MHz RF Transmitter EEL-5666: Intelligent Machines Design Lab

Sonar n Provides analog interface ¡ n n n The higher the voltage the further away the object. Start time of each sonar can be controlled. Readings obtained 50 ms after start. Sequentially check each sonar ¡ If returned value below threshold then obstacle detected. EEL-5666: Intelligent Machines Design Lab

Jerry’s Design – Close IR n Analog output ¡ ¡ Brighter areas give lower voltages. If returned value above threshold then obstacle detected. EEL-5666: Intelligent Machines Design Lab

Jerry’s Design - Behaviors n Wandering ¡ ¡ Randomly moves around avoiding obstacles. If “food” (black spot) is detected it will switch to grazing behavior. Frequently looks for Tom. If Tom is detected it will immediately switch to running behavior. EEL-5666: Intelligent Machines Design Lab

Jerry’s Design - Behaviors n Grazing ¡ ¡ Holds on top of food for a preset time. Will slowly move across the food until passes it completely. Infrequently looks for Tom. If Tom is detected it will switch to running behavior. EEL-5666: Intelligent Machines Design Lab

Jerry’s Design - Behaviors n Running ¡ ¡ Moves away from Tom as fast as possible. Turns frequently in order to escape Tom. If caught, will stop and wait to be reset. If preset time has gone without being caught will return to wandering behavior. EEL-5666: Intelligent Machines Design Lab

Special Sensor - RF Link n n www. sparkfun. com Tom: ¡ ¡ n Jerry: ¡ ¡ n 434 MHz Receiver 315 MHz Transmitter 315 MHz Receiver 434 MHz Transmitter Links used to communicate robot status to determine exhibited behaviors. EEL-5666: Intelligent Machines Design Lab

RF Link Difficulties n n Receiver designed to “lock on” to signal. Therefore, sender must transmit alternating bits for receiver to lock onto the baud rate. Receiver will increase gain until it finds a detectable signal. Therefore, it will output garbage if the transmitter is not sending. EEL-5666: Intelligent Machines Design Lab

RF Link difficulties n n Receiver must “synchronize” with transmitter. If a transmission looks like: 0 0 0 1 1 0 1 0…, the USART has no real way to recognize the start of a transmission. Over a wired link, the line is usually high and is pulled low using the start bit. This is not the case in RF. Finally, the receiver has a band-pass filter centered at its tuned frequency. When the robots get far enough away, this is washed out by the local transmitter. EEL-5666: Intelligent Machines Design Lab

RF Link Algorithm n n n Use interrupts to continually send 0 x. AA, the locking code. When want to transmit, send out 0 x. FF to resynchronize the link Finally, send out data. EEL-5666: Intelligent Machines Design Lab

Conclusions n n n Both robots successfully avoid obstacles. Wireless successfully incorporated. Tom successfully detects Jerry and will head towards him. EEL-5666: Intelligent Machines Design Lab

Possible Improvements n More reliable detection method. ¡ IR not always reliable and dependent on environment. EEL-5666: Intelligent Machines Design Lab

Questions? n Acknowledgements ¡ ¡ ¡ Dr. A. A. Arroyo Dr. E. M. Schwartz Julio Suarez Adam Barnett Thomas Mc. Donley Jason Taylor EEL-5666: Intelligent Machines Design Lab