Design and development of attitude control system (ACS) using COTS based components for small satellites

This paper deals with the attitude control of small satellites using commercial off the shelf (COTS) components in order to keep the overall cost within financial constraints. The design involves the use of gyroscopes and digital sun sensors (DSS) for attitude determination while three reaction wheels have been employed as actuators. Two different control schemes, proportional & derivative (PD) and linear quadratic regulator (LQR), are applied. Attitude control algorithms have been developed and optimized using Matlab based simulations for different scenarios and PD controller has been finally selected due to better performance. Finally, attitude control algorithms have been embedded in hardware. Telemetry and Telecommand signals between on board computer (OBC) system and ACS are transmitted through the CAN bus. The performance of embedded system has been analyzed and the results obtained are very close to the simulations.