Attitude Determination and Control Karla Vega University of

Attitude Determination and Control Karla Vega University of California, Berkeley 11/30/2020

Outline Requirements Hardware Attitude Determination Dynamics Attitude Control Types Disturbances Integration and Test Summary ACS in Cube. Sats CINEMA *Lecture notes from Dr. Glenn Lightsey’s Spacecraft Dynamics and Controls Graduate Course at University of Texas at TRIO-CINEMA Meeting 11/30/2020 Austin

Getting Underway TRIO-CINEMA Meeting 11/30/2020

Requirements and Flowdowns TRIO-CINEMA Meeting 11/30/2020

Tree Diagram TRIO-CINEMA Meeting 11/30/2020

Impact of ACS on S/C Configuration TRIO-CINEMA Meeting 11/30/2020

Some Standard Configurations TRIO-CINEMA Meeting 11/30/2020

Hardware TRIO-CINEMA Meeting 11/30/2020

Star Sensors TRIO-CINEMA Meeting 11/30/2020

Earth Sensors TRIO-CINEMA Meeting 11/30/2020

Earth Sensors Cont. TRIO-CINEMA Meeting 11/30/2020

Sun Sensors TRIO-CINEMA Meeting 11/30/2020

Magnetometers TRIO-CINEMA Meeting 11/30/2020

GPS TRIO-CINEMA Meeting 11/30/2020

Typical External Sensor Performance TRIO-CINEMA Meeting 11/30/2020

Gyros TRIO-CINEMA Meeting 11/30/2020

TRIO-CINEMA Meeting 11/30/2020

TRIO-CINEMA Meeting 11/30/2020

Typical Gyro Performance TRIO-CINEMA Meeting 11/30/2020

Typical Inertial Sensor Performance TRIO-CINEMA Meeting 11/30/2020

Sensor Selection TRIO-CINEMA Meeting 11/30/2020

Sensor Selection Continued TRIO-CINEMA Meeting 11/30/2020

Actuators Torque Coils Wheels Reaction Wheels Momentum Wheels Controlled Moment Gyros Thrusters TRIO-CINEMA Meeting 11/30/2020

Wheels TRIO-CINEMA Meeting 11/30/2020

Wheels Continued TRIO-CINEMA Meeting 11/30/2020

Thrusters TRIO-CINEMA Meeting 11/30/2020

Thrusters Continued TRIO-CINEMA Meeting 11/30/2020

Attitude Determination and Control TRIO-CINEMA Meeting 11/30/2020

Attitude Determination Frames of Reference Parameterization Geometry Estimation Statistics Observability TRIO-CINEMA Meeting 11/30/2020

Attitude Parameterization TRIO-CINEMA Meeting 11/30/2020

Propagating Attitudes TRIO-CINEMA Meeting 11/30/2020

Propagating Euler Angles TRIO-CINEMA Meeting 11/30/2020

Propagating Quaternions TRIO-CINEMA Meeting 11/30/2020

Geometry of Attitude Determination TRIO-CINEMA Meeting 11/30/2020

Implementation TRIO-CINEMA Meeting 11/30/2020

Implementation Continued TRIO-CINEMA Meeting 11/30/2020

Implementation Continued TRIO-CINEMA Meeting 11/30/2020

Estimation Theory: combining several measurement TRIO-CINEMA Meeting 11/30/2020

Dynamics: Euler’s Equations TRIO-CINEMA Meeting 11/30/2020

Integration TRIO-CINEMA Meeting 11/30/2020

Attitude Control TRIO-CINEMA Meeting 11/30/2020

Disturbances TRIO-CINEMA Meeting 11/30/2020

Some Typical Disturbance Torque Magnitudes TRIO-CINEMA Meeting 11/30/2020

Gravity Gradient TRIO-CINEMA Meeting 11/30/2020

Gravity Gradient, circular orbit TRIO-CINEMA Meeting 11/30/2020

Stability Diagram for GG in circular Orbit TRIO-CINEMA Meeting 11/30/2020

Effects of Elliptical Orbits TRIO-CINEMA Meeting 11/30/2020

Design of GG Satellites TRIO-CINEMA Meeting 11/30/2020

Magnetic Attitude Control TRIO-CINEMA Meeting 11/30/2020

Magnetic Controls, Continued TRIO-CINEMA Meeting 11/30/2020

Using Magnets TRIO-CINEMA Meeting 11/30/2020

Comments of Field Models TRIO-CINEMA Meeting 11/30/2020

Momentum Bias TRIO-CINEMA Meeting 11/30/2020

Integration and Test TRIO-CINEMA Meeting 11/30/2020

I&T Continued TRIO-CINEMA Meeting 11/30/2020

Summary TRIO-CINEMA Meeting 11/30/2020

ACS in Cube. Sats Passive Control Magnets aligned with magnetic field Active Control Torque Coils Solar panels as sun sensors Reaction Wheels ($$) Digital sun sensors ($$) TRIO-CINEMA Meeting 11/30/2020

ACS: CINEMA (more on Wednesday) Spin-stabilized satellite Desired Attitude: Ecliptic normal System pointing requirement Science: ± 10° Determination: ± 1° Control: ± 1° Hardware V-slit sun sensor Solar panels (3 current sensors) TBR Magnetometer Torque Coil TRIO-CINEMA Meeting 11/30/2020

Some Useful References TRIO-CINEMA Meeting 11/30/2020