Adaptive backstepping fuzzy control for servo systems with backlash
考虑齿隙伺服系统的反步自适应模糊控制

An approximate dead-zone function is introduced to build the model of the electromechanical servo system with unknown parameters and nonlinear backlash; the method for selecting parameters of the approximate dead-zone function is also given. Two adaptive fuzzy logic systems are employed to approximate unknown parameters and the nonlinear part of the servo system online, to avoid the derivation of adaptive law for each unknown parameter. Adaptive fuzzy controller is also developed based on backstepping method, which effectively inhibits the influence of parameter uncertainties and backlash nonlinearity. It is theoretically shown by using Lyapunov function that the position tracking error converges exponentially. Finally simulations show that the adaptive backstepping fuzzy controller not only reduces gear transmitting torque oscillation significantly, but also have higher accuracy and robustness in performances than PID controller.