柔性关节驱动机构的复合神经动态面控制

Composite Neural Dynamic Surface Control of the Flexible Joint Driving Mechanism

  • 摘要: 为实现柔性关节驱动机构的高精度位置控制,首先对其建立了包含LuGre摩擦模型、柔性变形和外界扰动力矩等非线性因素的动力学模型.然后针对该模型设计了复合神经动态面控制器,模型的不确定项通过径向基函数(RBF)神经网络(NN)在线逼近和补偿,为提高神经网络对不确定项的逼近速度和逼近精度,结合预测误差和补偿跟踪误差构建了神经网络权值的复合自适应律.通过李亚普诺夫理论证明了系统一致最终稳定有界.与传统动态面控制相比,仿真结果表明复合神经动态面控制器提高了神经网络对不确定项的逼近精度和逼近速度,提高了柔性关节驱动机构的位置跟踪精度.

     

    Abstract: To realize high-precision position control of the flexible joint driving mechanism, we establish a dynamic model that includes nonlinear factors such as the LuGre friction model, the flexible deformation, and the external disturbance torque. On the basis of this dynamics model, we propose a composite neural dynamic surface controller. The uncertainties of the model are approximated and compensated online by using the RBF neural network (NN). To improve the approximation speed and the accuracy of uncertainties, we construct composite adaptive laws for neural weight updating based on prediction and compensated tracking errors. We guarantee the uniformly ultimate boundedness stability via Lyapunov theory. Compared with the classic dynamic surface control method, the proposed control method is fast and achieves better accuracy in uncertainty approximation, as indicated by simulation results, and the position tracking accuracy of the flexible joint driving mechanism is improved.

     

/

返回文章
返回