FAST二次精调实验平台的伺服系统设计

基于Stewart平台的馈源接收机位姿主动减振定位机构的控制，是500m口径球面射电天文望远镜（FAST）项目实现的关键。以大射电望远镜馈源二次精调平台为基础，研究将Stewart平台机构作为精调平台实现对大幅度的多自由度的减震控制。提出了基于Stewart机构的控制方案，利用PMAC卡实现机构的多轴控制，控制环节采用底层开发的开放伺服PID控制策略，加上最小二乘预测提高精度，实验证明该方案满足FAST需要的减震精度要求，该实验结果将为FAST原型设计提供可执行性的依据。

Design of the Servo System of the Fine Turning Platform of FAST

Active large-amplitude vibration control based on the Stewart platform is researched. The problem arises from a large radio telescope in which the astronomical equipment is mounted on a platform to be stabilized by adjusting six scalable actuators, while the base platform of the mechanism itself is carried by a vibrating cable-car that moves along flexible cables. A control algorithm based on RtLinux is implemented. A client and server system is designed, together with a PMAC motion control card controlling the servo system. PMAC's open servo algorithm property provides a convenience software and hardware interface for the improvement of the control algorithm, and least-square estimation is used to improve the precision. The experiment result testifies that the control algorithm can satisfy the requirement of the FAST.