Fuzzy attitude control system for a small satellite orbit maintenance using pulsed plasma thruster

This paper studies the application of pulsed plasma thrusters for autonomous station keeping of a remote sensing three-axis stabilized spacecraft flying at a low altitude due to inherent characteristics, while a fuzzy logic feedback law is employed for attitude control. Attitude stabilization is addressed using a reaction wheel and two magnetic torquers. The controller has been realized by means of a MIMO fuzzy controller with a knowledge base composed by 75 logic rules (25 logic rules for per axis). The Mamdani controllers use a standard max–min inference process and a fast center of area method to calculate the crisp control signals. Using hybrid actuators solve the singularity problem that often occurs in active magnetic control methods. The main features of the proposed control strategy are: simplicity in spacecraft control system design and development, increased robustness for automatic control reconfiguration and model uncertainty, reduction in development and production cost for flight control systems, autonomous on-board control features. Numerical simulation was carried out to testify the efficiency of the control system during station keeping. The satellite mass is approximately 60 kg, and has a bus power of approximately 100 W. The PPT's nominally aligned to the spacecraft velocity vector or x direction in body frame. The PPT is designed to produce near 0.9 mN of thrust at a specific impulse of 500 s using 25 W of power when its whole systems weighs less than 1.5 kg and is a breech-fed parallel-rail ablative PPT.