针对大射电望远镜馈源舱跟踪定位问题,提出一种自适应滑模控制方法.从线性化模型出发.将模型偏差、风载荷视为系统外部扰动,通过引入参数自适应机制,在线估计外部扰动并加以补偿.采用Lyapunov稳定性理论,推导了舱索系统的多输入多输出自适应滑模控制律.在此基础上,针对大射电望远镜50m缩尺模型,采用离散悬索模型和自适应滑模控制方法对舱索控制系统进行了仿真,并与传统的PID控制方法进行对比.结果表明,采用自适应滑模控制使跟踪误差减小到约32%,并提高了抗风扰能力.
To improve the tracking accuracy and robustness against wind disturbances for a large spherical radio telescope, an adaptive sliding mode controller is proposed. Based on Lyapunov stability theorem, the multiple-input and multiple-output sliding mode control law is derived with the linear model of the system, in which the modeling error and wind force are considered as the external disturbance that is estimated and compensated on line. A series simulation is finished with the parameters of a 50-meter scaled large spherical radio telescope model, and the results show that the tracking error is reduced to around 32% and the robustness of system is improved with the sliding mode control comparing with tranditional PID control.