基于分布式控制系统的空间大型末端执行器抓捕策略

Capture Strategy Based on a Distributed Control System for a Large-scale Space End-Effector

针对空间大型机械臂因其关节和臂杆柔性带来的抓捕前定位问题,为一种具有柔性捕获接口的新型末端执行器设计了分布式控制系统,并建立了以捕获环收缩速度为主要控制对象的抓捕策略,可实现稳定且高效的抓捕.其中,该控制系统由传感器单元、上层控制单元和3个模块化的底层驱动单元组成.传感器单元和底层驱动单元集成在末端执行器内部,采集系统的位置、力/力矩、电流及温度等传感器数据并实现伺服电机的底层驱动;上层控制单元通过高速总线可同时向3个底层驱动单元发送控制指令及控制参数,协调末端执行器执行抓捕、拖动及锁定操作.实验表明,基于该分布式控制系统,所提出的抓捕策略有效地提高了大型机械臂抓捕操作的可靠性.

For the positioning problem of a large-scale space end-effector from the flexible joints and elastic beams before the capture operation,a distributed control system is proposed for a newly developed end-effector equipped with flexible capture interface.A capture-snare-speed-oriented strategy is established based on distributed control system;thus,a reliable and effective capture operation can be realized.The designed system is composed of a sensor unit,a top-level control unit,and three modularized bottom-level driving units.The sensor unit and the bottom-level driving unit are integrated inside the end-effector, and used to obtain the data of position,force/moment,current and temperature sensors and drive the servo motors of the system.The top-level control unit sends control commands and parameters synchronically to the three bottom-level driving units through a high-speed bus for coordinating the catching,dragging and latching operations of the end-effector. Experimental results show that,in support of the distributed control system,the reliability of the capture operation can be effectively improved by using the proposed strategy.