Research on explicit model predictive control method for horizontal vibration of high-speed elevator car system

The high-speed elevator car frame system, as a multi-input multi-output system (MIMO), has the characteristics of multiple constraints, complex coupling relationships, and high dynamic adjustment requirements. In response to the above characteristics, this paper studies a horizontal vibration suppression strategy for a high-speed elevator car frame system based on explicit model predictive control. Firstly, considering the multifactor coupling phenomenon between the components, such as the car and the car frame, the dynamic equation of the semi-active control system for horizontal vibration of the car frame high-speed elevator was established. Secondly, an explicit model predictive control strategy (EMPC) for elevator semi-active systems is constructed by combining offline calculation of the optimal control law for elevator state feedback with online search, integrating multiple constraints in the car frame system into a quadratic programming problem for global optimization, effectively solving the control instability problem caused by multiple constraints in elevators. Fully considering the multivariable coupling relationship of high-speed elevators, joint optimization of multiple inputs in the elevator system is carried out based on multiparameter programming technology to minimize the control objective function. Establish an elevator state prediction model and call an offline state feedback control law to obtain the optimal control strategy that adapts to the new dynamics when the elevator system dynamically changes with load and external environment. Finally, the acceleration time-domain and frequency-domain responses of the semi-active control system for horizontal vibration of high-speed elevators under two operating conditions were analyzed through simulation calculations and compared with the numerical results under sliding mode control and traditional PID control. The performance of EMPC has significantly improved compared to passive suspension. Compared with sliding mode control, the proposed EMPC reduces the horizontal vibration acceleration and angular acceleration by over 34.8% and 61.7%, respectively. Further, verify the proposed EMPC control method's effectiveness and robustness in suppressing high-speed elevators' horizontal vibration.