Analysis and Design of a Remote Center Compliance Universal Joint

This paper presents a novel mechanical design of a lower mobility remote center compliance linkage. This mechanism consists in three platforms connected by three legs with universal joints. Two of these platforms are attached to the ground while last one is the mobile platform. Using screw theory, it is first demonstrated that this mechanism allows its mobile platform to rotate around a fixed point in space without having a joint directly connected to this point. Indeed, knowing the mobility of the two former platforms, it is possible to define a wrench system for each leg and thus, find the reciprocal twist system of the mobile platform. Then, the results of the optimization of the mechanism’s design through a genetic algorithm is presented using the conditioning of its Jacobian matrix as a criterion. Finally, a compliant version of the mechanism is developed and a finite element analysis (FEA) simulation demonstrates the proper mobility of the system under typical loading scenarios.