RLV再入段模糊NLPID抗干扰控制器设计

Design of Fuzzy NLPID Anti-Interference Controller for RLV Reentry Phase

可重复使用运载火箭(Reusable Launch Vehicle,RLV)再入段气动环境复杂,针对RLV再入段姿态控制抗干扰和弱鲁棒性问题,提出一种模糊非线性PID(Nonlinear PID,NLPID)抗干扰控制器。为提高NLPID控制器的抗干扰和滤波能力,采用了新型跟踪微分器。为克服参数摄动和外界扰动对姿态控制系统的影响,总结了模糊NLPID控制器参数影响系统响应速度、超调量的规律;根据上述规律改进模糊规则,以攻角误差及其微分为输入量,经过模糊推理得到速度因子和增益的修正量。与模糊PID控制器仿真对比,结果表明:模糊NLPID控制器的响应速度和抑制超调效果更佳,削弱了外界扰动对模糊推理过程的影响,具有自适应能力强和调节参数少的特点。

The aerodynamic environment of the re-entry stage of the reusable launch vehicle(RLV) is complicated. Aiming at the anti-interference and weak robustness of the attitude control of the RLV re-entry stage, a fuzzy nonlinear PID(NLPID) anti-interference controller is proposed. In order to improve the anti-interference and filtering ability of the NLPID controller, a new tracking differentiator is adopted. In order to resolve the influence of parameter perturbation and external disturbance on the attitude control system, the law of fuzzy NLPID controller parameters affecting the system response speed and overshoot is summarized, and due to the improved fuzzy rule according to the above law, the speed factor and gain correction amount are obtained after fuzzy inference by taking the angle of attack error and its derivative as input. By comparing with the simulation of the fuzzy PID controller, the results show that the fuzzy NLPID controller has better response speed and overshoot suppression effect, which weakens the influence of external disturbance on the fuzzy inference process and has the characteristics of strong adaptive ability and fewer adjustment parameters.