直线电机伺服定位系统时间最优鲁棒控制

Robust time-optimal control of a linear motor positioning system

无铁心永磁同步直线电机伺服定位系统点位运动控制中Bang-Bang控制满足庞特里亚金极小值原理条件。为确定Bang-Bang控制中的切换时间,提出一种基于粒子群优化算法的切换时间计算方法。为保证电机系统的稳定性和鲁棒性,提出先用Bang-Bang控制后用快速终端滑模控制的两阶段控制方案。系统起始阶段采用Bang-Bang控制保证系统变量以最快速度向平衡点收敛。当位置变量进入终端状态某邻域时,系统切换为滑模控制,使系统具有很强的鲁棒性。仿真结果表明,同传统切换时间计算方法相比该方法大大降低了陷入局部极值的可能性,具有更好的可实施性。实验结果表明,该复合控制算法能使电机伺服定位系统从起始点在最短时间内运动至目标点并保持很好的稳定性和控制精确度。

In this paper,a robust minimum-time control technique is presented for point-to-point motion of a linear positioning system with an ironless permanent magnet linear synchronous motor（ILPMLSM）.For this system,a time-optimal control satisfying Pontryagin＇s minimum principle is in Bang-Bang fashion.A switching time computation algorithm using particle swarm optimization（PSO） is proposed to obtain bang-bang control law.Due to parameter variations and other disturbances,the obtained bang-bang control would result in undesirable chattering towards the end of the desired final state.To tackle this problem,a two-phase control scheme is developed in this work.In the first phase（gross motion control）,a bang-bang control law is applied,while in the second phase（fine motion control） a fast terminal sliding mode control（FTSMC） technique is employed to guarantee the convergence of the state to the desired final state.The simulation results show that the proposed method is more applicable and the probability of tramped into local extremum is dramatically reduced.Experimental results demonstrate that the proposed control scheme is effective and robust against parameter variations and other disturbances.