含间隙非线性的Wiener-Hammerstein系统复合补偿控制

Combined compensation control for Wiener-Hammerstein systems with backlash nonlinearities

针对含非对称间隙环节的Wiener-Hammerstein系统提出了一种新的由输出反馈和间隙动态逆补偿构成的复合控制方案.首先应用参数化分段线性表达式设计了未知参数的整体估计模型,可同时估计线性参数和间隙的特征参数,然后提出了一种新的误差有界的间隙动态逆模型,该模型可使得驱动信号能在间隙的不同线性段之间快速切换,在此基础上设计了鲁棒补偿控制律,同时对输入线性环节采用输出反馈控制构建了复合控制器,通过李亚普诺夫方法证明了闭环系统的稳定性.带减速器的单电机伺服系统模型的仿真结果表明该方法在跟踪精度良好的同时可使系统动态响应满足要求.

For Wiener-Hammerstein systems with asymmetric backlash nonlinearities, we propose a novel combined compensation control consisting of the output feedback and a dynamic inverse compensation for backlash. The piecewise linear parametric representation is first utilized to simultaneously estimate the characteristic parameters of the asymmetric backlash and the unknown coefficients in the linear transfer function. Then, we build a new error-bounded dynamic inverse model for the backlash; this model makes it possible for the driving signal to be quickly switched between different line segments of the backlash. On this basis, we develop the robust compensation law. Meanwhile, by using output feedback, we build a compound controller for the input linear loop. The stability of the closed-loop is proved by means of Lyapunov method. Simulation is carried out on a single-motor servo system with speed reducer. Results show that the proposed method provides not only excellent tracking accuracies, but also the desirable dynamic response as well.