空间精密跟瞄Hexapod平台作动器研制与实验

针对基于并联机构的空间精密跟瞄Hexapod平台的大行程、高性能要求,通过对现有主动元件的分析,从作动器角度研制了以滚珠丝杠作动器为宏动部分、压电作动器为微动部分的大行程高频响精密复合作动器,测试了复合作动器的行程、开环定位精度及动态特性,以dSPACE半物理仿真系统为核心建立了实验系统,进行了复合作动器单自由度精确定位实验和振动主动控制实验.由结果可知,复合作动器作动行程超过50mm、经微动部分补偿后的整体定位误差小于1μm、正弦持续扰动下采用自适应滤波ADC(Active Disturbance Canceller)方法使振幅下降90%以上.结果表明,将此复合作动器应用于空间高稳定精密跟瞄Hexapod平台是完全可行的.

Development and experiment of active member for space-base precise pointing Hexapod

A platform scheme that provides precision pointing and active vibration isolation for space-base payloads based on parallel mechanism-Hexapod was proposed. With the analysis of the current Hexapod-s actuators, a high precision dual-driving hybrid actuator was developed. It integrated ball-screw actuator as macro-moving stage and piezoelectric stack actuator as micro-moving stage. Key characteristics of the hybrid actuator were measured at first, such as stroke, macro-moving stage open-loop positioning accuracy and micromoving stage dynamic property. An experiment system based on MATLAB/dSPACE environment was established and the actuator single degree-of-freedom positioning experiment and active vibration isolation experiment were carried on then. Experiment results show that the hybrid actuator stroke exceeds 50mm and its whole positioning error being less than 1μm with the close-loop compensation of the micro-moving stage. The results also show that when continuously excited at 30Hz on one end of the hybrid actuator, vibration on the other end is decreased more than 90% with the adaptive filtering active disturbance canceller (ADC) algorithm. The study indicates that the hybrid actuator is expected to apply to precise pointing Hexapod.