A 6-DOF heavy-load parallel manipulator with RFTA and its application

This paper proposes a 6-DOF (Degree of Freedom) heavy-load parallel manipulator with a redundant actuation and fault-tolerant actuator (RFTA). The novel RFTA model of the proposed manipulator is developed and its working principle is described. In order to achieve the given motion, the mathematic models of the proposed manipulator with the RFTA are derived. As a prototype of an earthquake simulator, two experiments are performed. The experimental results demonstrate that the RFTA is able to supply the required double driving force and appropriate used as an actuator of a low frequency earthquake simulator. The results of the fault-tolerant experiment show the earthquake simulator with the RFTA is capable of tolerating some local faults. The proposed parallel manipulator can also be applied under other heavy-load environments.