Design of space manipulator on-orbital reconfigurable high accuracy modular joint

A newly designed space manipulator on-obital reconfigurable modular joint was described. The rated joint torque requriement was calculated based on the manipulator task dynamic simulation. The drive chain of the joint consisted of DC motor, gearbox, and harmonic drive giving the joint high weight/load ratio and high accuracy whose mechanical error is less than 1 arc min. A high accuracy joint control system was developed based on FPGA which could get accurate sensor information. The calbes go through the core of joint and the electronic board is mounted in the inner housing of joint. These features above give the joint a higher compactablility. The joint could be mounted or dismounted on-orbital which allows the manipulator service permanently on space. At the end, the performance of the joint prototype was tested on special testbed by using PD control.