Robust Two-degree-of-freedom Control for High-Rise/High-Speed Elevators

The vertical motion control systems and robust two-degree-of-freedom (2DOF) control for high rise/high speed elevators are discussed in this paper. The control aim is that under the desired control performance realizes robust tracking and releveling control and let the system have good robustness for uncertainties. A kind of robust 2DOF control method is proposed for elevators on the basis of vertical motion control description. This method can reject effectively the affect of parameter variation for system and the good tracking characteristic, disturbance rejection characteristic, robustness and high precision releveling performance can be achieved simultaneously. First, the design of speed controller is converted into a standard Hinfin control problems. Second, with the help of LMI approach, a output feedback sub-optimal Hinfin controller is obtained. Finally, an Hinfin optimal controller is gained by solving a convex optimization problem so as to guarantee system robustness. The simulation results show that this method is effective.