Design of the fault-tolerant control system for space robotic joint

To meet the requirement of high reliability of space robotic system, a fault-tolerant joint control system has been developed based on dual winding permanent magnet synchronous motor. Compared with the traditional scheme, the presented joint control system, maintaining relatively small sizes and weights of the essential joints, is able to withstand multiple non-repeating faults occurred in two redundant subsystems. Non-stop run can also be attained even though either of the running subsystems has a power failure. Hence, the problem existing in the traditional control system of dual winding motor that the faults occurred in the controller or power sub-system are intolerable, has been solved with an improvement in the fault-tolerant capability of the joint. The fault-tolerant control strategy applied to the motor drive system and controller has been designed. And on-line fault detection can be realized based on the redundant information of joint sensor, even though two position sensors fail at the same time.