Towards an Integrated Fault Tolerant Control for ESTCube-2 Attitude Control System

The development of attitude control systems in recent years have increasingly focused on Fault Tolerant Control (FTC) capabilities to deal with sensor and actuator faults as well as actuator saturation. The FTC capabilities could either be active or passive with the former involving real-time fault detection and isolation schemes. A detailed integrated architecture for FTC is presented for the ESTCube-2 nanosatellite mission. The design involves centralized and decentralized Anti-Windup (AW) compensator and an Adaptive Neuro-Fuzzy Inference System (ANFIS) controller structure for different attitude control modes. The ANFIS controller switches to implementing an AW compensator in case of specific reaction wheel actuation saturation. A Proportional Derivative (PD)-like controller is designed to ensure it satisfies the requirement under nominal conditions thereby allowing the proposed integrated FTC architecture to be implemented. The system is designed with the ESTCube-2 nanosatellite model with magnetorquers, reaction wheels and thrusters as actuators. Numerical and simulation results demonstrate the effectiveness of the proposed method in efficiently addressing attitude control faults and actuator saturation.