Electronics and Control System Design and

DevelopmentSeth Bourn

with Ted Hench, Kevin McIntire, & Sonya Pursehouse

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

Current Status

• Provide GPS Payload Tracking• Maintain Sensor Operation and

Scientific Data Handling• Stabilize Payload After Separation

and During Turbulence

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))

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

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

Recent Issues

• Ongoing problem of sensor accuracy• Signal Noise• Microcontroller latency during servo

actuation

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.

On the Horizon

• Development of AVR Microcontroller to replace current BASIC Stamp

• Addition of second BASIC Stamp to alleviate processing load and increase speed.

Thank You

Questions?