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

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.