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