柔性支撑Stewart平台动力学建模与轨迹跟踪控制

为了实现FAST(five hundred meter aperture spherical radio telescope)二级精调稳定平台的高精度轨迹跟踪,建立了采用电动缸驱动的Stewart平台完整动力学模型,基于控制律分解法进行了动力学模型的全局反馈线性化,针对基座的外界干扰和机构未建模动态的不利影响,在Stewart平台操作空间设计了基于基座平台加速度前馈的PID控制器。建立了现代机电系统仿真模型,对柔性支撑基座存在干扰情况下Stewart平台的动力学与轨迹跟踪控制问题进行了数值仿真,结果表明所设计的控制系统具有跟踪精度高、动力性能平稳和鲁棒性强的优点。

Dynamical modeling and trajectory following control of the flexible supporting Stewart platform

To achieve the high-precision trajectory following of the secondary stabilizing platform of FAST(five hundred meter aperture spherical radio telescope),the integrated dynamical model of the Stewart platform including the electrical cylinder is established,the global feedback linearization of the dynamical model is implemented based on the control law partitioning approach.To overcome the disadvantages of the external disturbance on the base and the unmodeled flexibility of the mechanism,a PID controller with base acceleration feedforward is designed in the operational space of the Stewart platform.A modern mechatronic simulation system is constructed,and the numerical simulation of the dynamic and trajectory following control of the flexible supporting Stewart platform with presence of the base disturbance is carried out.The result shows that the presented control scheme has the advantage of high accuracy,stable dynamics and strong robustness.