Repetitive adaptive control based on sliding filter observer in servo turntable

A repetitive adaptive compensation scheme based on observer is proposed to improve low speed position tracking precision for the nonlinear dynamic friction and periodic force ripples in a DC motor turntable system. Based on LuGre friction model, the adaptive component is used to compensate the dynamic friction, while the repetitive component is used to restrain force ripple. At the same time, dual sliding filter is adopted to approximate the parameter estimation error of the observed state so that the parameters update rate can be driven by tracking error signal as well as estimating error signal to improve the position tracking performance. The system asymptotic stability is guaranteed by Lyapunov function. Simulation results verify contrastively the effectiveness and superiority of the repetitive adaptive compensation scheme.