Tracking and Synchronization Control for Multimotor Servo Systems Based on Fixed-Time Command Filtered Approach

In multimotor servo systems, load tracking and motor synchronization are two key control objectives, necessitating the high-performance control design accompanied by high-precision measurements of position, speed, and current. This article presents a fixed-time command filtered control (CFC) strategy based on full-state measurements to simultaneously realize position tracking and speed synchronization. In the tracking control design, command filters are introduced to approximate derivatives of virtual control signals to avoid the “explosion of complexity” problem. An improved compensation mechanism with double fractional powers is constructed to further eliminate filtering errors. A fixed-time control approach is utilized to accelerate the convergence process and improve the tracking accuracy. In the synchronization control design, a practical grouping control is proposed to cooperate with the backlash elimination method, and the control inputs are superimposed on current commands to quickly attain speed synchronization. The fixed-time convergence of both the tracking error and the synchronization error is proved through Lyapunov theory. Experiments are conducted on a four-motor servo platform, and the obtained results demonstrate the effectiveness and practicality of the proposed strategy.