METEOR Guidance System

P07106

Nov 2006 – May 2007

Project Review

Project Goals

• Control system for rocket flight

• Actuation system for rocket maneuvering

• Flight ready electrical hardware

• Software implementation

• Flight simulation

People

• Dave– Control system– Simulation

• Ryan– Software– Horizon sensor

electrical

• Mark– Flight Computer– Electrical hardware

• Ben– Actuations system– Mechanical assembly

• Joe– Horizon sensor

radiometry– Camera Lens

Assembly– Actuator testing

systems– Project management

Control System

• Utilize sensor inputs

• Determine response

• Generate commands for actuators

Complementary Filter

PID Controller

Sensors

• Inertial Measurements Unit– Off the shelf IMU– 3 axis acceleration– 3 axis rotation rate– Digital output 150 Hz

• Horizon Sensor– Custom made– CMOS imaging sensor– Wide angle lens– Band Pass filtered

IMU• Internal ADC with temperature

compensation• RS-422 Digital Output• 5G Accelerometers on all three

axis• 300 Deg/s Rate Gyros on all three

axis• 35G Accelerometers on two axis• Non Idealities

-Acceleration dependant Gyro bias

Horizon Sensor

Software

Image processing

Equidistant point algorithm-Removes curvature of earth-Simple orientation extraction

Pixel luminosity thresholding-Easy to implement-Uses constant threshold value-Can use a variable threshold lookup table vs altitude

Flight Computer

• Custom design• TI 2808 DSP• 4 layer PCB• SMT construction

Block Diagram

Actuators

• 4 Vernier jets• Powered by pressurized NOX• Gas generated from boiling

liquid• Jets rotate on BB Rotary

unions• Controlled by PWM servo

actuators and push-pull linkages

Nozzles• Converging-diverging

design• Throat area matched

for flow rate• Area ratio optimized

for thrust• Custom tooling for

fabrication• Thrust & flow tested

Motion control

• NOX feed line with rotary union

• PWM controlled digital servo

• Response measured experimentally

Simulation

• 2D simulations– Spec thruster output– Spec mass and burn time to other groups– Determine worst case trajectory

• 3D simulations– Test control system– Test actuator response– Spec thrust axis tolerances

2D simulations

3D Simulations

Conclusions

• Micron CMOS sensors not performing as indicated in spec sheet

• Horizon sensors n