机电伺服系统有限时间自适应反步控制方法研究

Research on Finite Time Adaptive Backstepping Control of Electromechanical Servo System

机电伺服系统存在未建模动态及不可避免的未知扰动,会严重影响系统的伺服性能。针对未知扰动下机电伺服系统惯性负载的角位移跟踪控制问题,考虑未建模动态对系统的影响,提出一种基于有限时间的模糊自适应指令滤波反步控制方法,能有效补偿系统中的未知扰动和未建模动态,具有良好的惯性负载角位移跟踪控制效果。针对系统中存在的未知外部扰动及未建模动态,结合滤波反步法和模糊控制理论,使用模糊逻辑系统逼近未知非线性动态同时构造自适应控制器。考虑到微分计算带来的计算爆炸问题,构建有限时间指令滤波器,降低了系统的计算复杂度,并通过设计滤波误差补偿机制,对滤波误差项进行补偿,保证滤波信号的逼近能力,提升系统跟踪控制性能。通过稳定性分析,证明所设计的控制器能够保证系统的跟踪误差在有限时间内收敛。最后通过仿真实验,验证了所提控制方法的有效性。

Electromechanical servo system has unmodeled dynamics and unavoidable unknown disturbances,which will seriously affect the servo performance of the system.Aiming at the problem of angular displacement tracking control of inertial load of electromechanical servo system under unknown disturbance,and considering the influence of unmodeled dynamics on the system,a fuzzy adaptive command filtering control method based on finite time was proposed.It could effectively compensate the unknown disturbance and unmodeled dynamics in the system,and had a good effect of angular displacement tracking control of inertial load.To deal with the unknown external disturbance and unmodeled dynamics in the system,combining the filter backstepping method and the fuzzy control theory,the fuzzy logic system was used to approximate the unknown nonlinear dynamics while constructing an adaptive controller.At the same time,considering the computational explosion caused by differential calculation,a finite time instruction filter was constructed to reduce the computational complexity of the system.And a filtering error compensation mechanism was designed to compensate the filtering error term ensuring the approximation ability of the filtering signal,and improving the tracking control performance of the system.Based on stability analysis,it is proved that the tracking error of the system can converge in a finite time under the presented control scheme.Finally,the effectiveness of the proposed control scheme is proved through simulation study.