柔性支撑Stewart平台动力学与控制仿真

Dynamic control simulation of Stewart platform with flexible suspension

大射电望远镜项目中,需用安装在由柔性索支撑的移动小车上的Stewart平台作为馈源稳定装置,而Stewart平台的运动平台和固定平台是动力学耦合的。该文采用多体系统动力学方法建立了柔性支撑的Stewart平台的数学模型,提出了基于预测平台位置的PD控制律。通过数值仿真对采用Stewart平台作为二次精调稳定平台降低馈源振动的有效性进行了研究。在此基础上,得出Stewart平行机构作为控制系统的可行性结论,同时为机构的正常运行提出了设计参数要求。

This paper studies the dynamics and control of the Stewart parallel mechanism for vibration reduction. The problem arises in a large radio telescope in which the receiver is mounted on a platform to be stabilized by a Stewart parallel mechanism, while the mechanism base is carried by a vibrating cable-car that moves along flexible cables. The two platforms in the Stewart platform are coupled in this application. The vibration reduction is studied by modeling the Stewart parallel mechanism as a multi-body system with an elastically restrained base platform. A PD control law is based on the position prediction. Control simulations with simulated wind excitations show that the vibrations of the receivers can be controlled by the Stewart platform. The results also give basic design parameters for the platform.