Electronics and Control System Design and Development

1. Seth Bourn with Ted Hench, Kevin McIntire, & Sonya Pursehouse Electronics and Control System Design and Development

2. Long Term Objective • Provide GPS Payload Tracking • Stabilize Payload After Separation and During Turbulence • Direct Payload to Pre-Determined Coordinate • Maintain Sensor Operation and Scientific Data Handling

3. Current Status • Provide GPS Payload Tracking • Maintain Sensor Operation and Scientific Data Handling • Stabilize Payload After Separation and During Turbulence

17. Control System Overview • Option 1: Accelerometer • Use Accelerometer to measure the acceleration of gravity • Accelerometer is mounted parallel to the surface of the earth • As angle of payload changes, accelerometer reading will equal: A(t) = g sin(θ(t))

18. Accelerometer Issue • The accelerometer works perfectly in the static case • Due to how the sensor must be mounted, it can give a false positive • Forward acceleration will read as a “nose up” pitch • Since forward velocity and pitch are coupled, these readings can skewed results

19. Control System Overview • Option 2: Gyroscope • Gyroscope measures the Rate of Rotation experienced by the payload • Reading is not biased by inertial translation • Challenges lie in programming and computational overhead

21. Recent Issues • Ongoing problem of sensor accuracy • Signal Noise • Microcontroller latency during servo actuation

22. Solutions • Zeroed Analog to Digital Converter • By providing a reference voltage, errors were reduced from 10% to 0.1% • Research into Secondary Controller for Servo Actuation • Possibility of using a 4017 Decade Counter to handle pulsing output for Servos.

23. On the Horizon • Development of AVR Microcontroller to replace current BASIC Stamp • Addition of second BASIC Stamp to alleviate processing load and increase speed.

24. Thank You Questions?