Adaptive command filter constraint control of rolling mill torsional vibration under current harmonic

An adaptive command filter control strategy was proposed to realize the asymptotic tracking of the roll speed, which successfully suppressed torsional vibration for the main drive system of the rolling mill with nonlinear friction, nonlinear damping, current harmonic, time-varying stiffness and unknown disturbance. A finite time predetermined performance method was proposed, so that the speed tracking error of the main transmission system was always constrained in the performance function and converged to its minimum boundary within the specified time. Based on the adaptive estimation of harmonic amplitude, the torque control law of the motor was obtained by using the filter backstepping method, which prevented the torsional vibration of the system caused by the input fluctuation and avoided the complexity explosion of the controller design, and the stability of the closed-loop system was strictly proved by the Lyapunov theory. The actual numerical simulation verified the effectiveness of the proposed control strategy.