Design of Dual-Drive Vertical Lift Servo System and Synchronous Control Performance Analysis

This article introduces a new dual-drive vertical lift servo system with a slipway that can be used to help people or other intelligent equipment complete high-altitude work better on the exterior wall of the high-rise buildings. In order to improve the system motion performance, enhance the robustness against the variation of system parameters and external disturbances, and minimize position error, a control scheme that integrates proportional-integral-derivative (PID) control and fast terminal sliding-mode control (FTSMC) is applied. The combination of the characteristics of both the PID and FTSMC ensures that the vertical lift servo system achieves motion stability, rapid convergence with small steady-state errors, and strong robustness against variation parameters and external disturbances. Potential rotational dynamics around the center of mass and synchronous error that mainly results from varying loads are reduced through the proposed control torque allocation scheme. The performance of the control scheme is investigated through extensive simulations. Moreover, a series of experimental studies demonstrate the effectiveness of the proposed synchronous position control method for the vertical lift system actuated by the two parallel servo drive systems.