Kinetostatic Modelling and Gravity Compensation of the TriMule Robot
Due to the gravitational field, the static torques of three actuators in the overconstrained parallel mechanism of the TriMule hybrid robot are quite different when the robot is horizontally placed, which may significantly affect the static and dynamic performance of the robot. This paper presents an approach for the gravity compensation of the TriMule robot. First, the kinetostatic model of the hybrid robot considering the gravitational effects is established in order to obtain the relationship amongst the gravitational force, externally applied wrench and static torques of actuators. In the light of this model, a method for the gravity compensation of the TriMule hybrid robot is proposed by taking into account the configuration characteristics of the robot. Simulation results show that the proposed method can effectively reduce the contribution of the gravity to the payload of one actuator and make the influence of gravitational field on the payloads of three actuators tend to be the same throughout the task workspace.
KeywordsKinetostatic modelling Gravity compensation Hybrid robot Screw theory
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This research is supported by National Key R&D program of China (Grant No. 2017YFB1301800) and National Natural Science Foundation of China (Grant No. 51622508).
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