Heavy lift launch vehicle technology of adaptive augmented fault tolerant control

Abstract

For heavy lift launch vehicle control system, an adaptive augmented fault tolerant control algorithm is proposed based on basic PID control, which mainly includes four parts: basic PID controller, fast on-line fault detection and reconstruction controller, adaptive vibration frequency identification algorithm and adaptive gain adjustment law. The basic PID controller is used for normal flight attitude control. Fast on-line fault detection and reconstruction controller applies adaptive observer for engine actuator fault detection, which realizes control quantity reconstruction based on fault information with pseudo-inverse method. Adaptive vibration frequency identification algorithm identifies each order rocket vibration frequency based on Steiglitz-mcBride method (SMM) with adaptive IIR filter, and then designs corresponding correction network. Adaptive gain control regulator is used to adjust open loop gain of the whole control system, so as to improve system control performance and stability. The simulation results show that the proposed algorithm can cope with attitude instability caused by actuator fault, high-altitude wind district aerodynamic disturbance torque and inaccurate elastic vibration frequency identification, etc., which indicates that the algorithm has relatively strong robustness and adaptability for interference and actuator fault.