S.T.E.V.E.(Speed Trap Enforcement VehiclE)

Final PresentationMichael Hattermann

April 16, 2002

Description1. Wait for a speeding car2. Chase after (follow) the speeding car3. Pull over the speeding car

Electronics Board• HC12 EEL4744 board

– CPLD– 8k EEPROM– Serial port– 4 PWM channels– 8 A/D ports– 8 Input capture/Output compare ports

• 24k RAM memory(*)• 1 LED output port• Output port connected to dual 7-segment display• Low battery indicator

(*) Not all of it works

Platform

Platform Design Goals• Big enough to hold

electronics board• Look like a cop car

Actuation• 2 DC gear head motors• Motor Driver

– National LMD18200 H-bridge– Optically isolated from electronics board

Obstacle AvoidanceSensors• Sharp GP2D12 Analog IR detectors (40 kHz)• Bump switches

Features• Smooth motor

control• Veer from distant

objects• Randomness

Object Following

Features• >180° field

of vision• Object

avoidance when lost

• Speed control algorithm

Sensors• Hacked LiteOn IR detectors (56kHz)

Speed DetectionSensor• Laser break-beam system• LiteOn digital IR receivers (56kHz)

Features• Similar to real

speed trap• Know direction

of passing object

Conclusion

• HC12 good, 4744 board bad• DC motors worth the effort• Need to integrate subsystems

Questions/Comments