Design and Simulation of Attitude Determination and Control Subsystem of CubeSat Using Extended Kalman Filtering and Linear Quadratic Gain Controller

This paper describes an integral scheme of the design and simulation of the Attitude Determination and Control Subsystem (ADCS) of CubeSat. CubeSat is an educational low-cost, cube-shaped Pico spacecraft. Attitude Determination (AD) is the problem of expressing the orientation of a spacecraft with respect to a given coordinate system. Three axis magneto-resistive digital magnetometer is selected as an attitude sensor. The International Geomagnetic Reference Field (IGRF) is used as reference for magnetometer to obtain attitude information. An enhanced orbit estimate/propagator is implemented to provide position information to IGRF model. Satellite environmental torque is modeled along with satellite kinematics and dynamics. Attitude estimation is done using Extended Kalman Filter (EKF) while the magnetic coils are used as actuators. Attitude Control is applied using Linear Quadratic Regulation (LQR) Controller. The designed ADCS is implemented in Matlab/Simulink.