超高层电梯的H_∞鲁棒控制

H_∞ robust control for high rise elevators

针对超高层超高速电梯,讨论了电梯垂直运动以及鲁棒二自由度控制方法.其目的是要在期望的控制性能下实现轨迹跟踪控制和再平层控制,并对系统的参数不确定性具有鲁棒性.在描述电梯垂直运动基础上提出了一种鲁棒二自由度控制,可以有效抑制参数变化对系统的影响,使系统同时获得良好的速度跟踪特性、干扰抑制、鲁棒性和精度高再平层性能.将速度控制器设计归结为标准的H∞控制问题;用线性矩阵不等式法得到输出反馈次优H∞控制器;最后通过求解凸优化问题得到H∞最后控制器,以保证系统的鲁棒性.仿真结果表明了该方法的有效性.

The vertical motion control system and robust two-degree-of-freedom （2DOF） control for high rise elevators were discussed. The control aim is to realize robust tracking and re-leveling and let the system have good robustness for uncertainties under desirable control performances. A kind of robust 2DOF control method is proposed for elevators on the basis of vertical motion control. The proposed method can effectively reject the effect of parameter variation on system performances. And the good tracking, disturbance rejection, robustness and high precision re-leveling characteristics are achieved. Firstly, the speed controller design is converted into a standard H∞ control problem. Secondly, with the help of linear matrix inequality （LMI） approach, an output feedback suboptimal H∞ controller is obtained. Finally, an H∞ optimal controller is designed by solving a convex optimization problem so as to guarantee system robustness. The simulation results show that the present method is effective,