Synthesizing of parallel robots using adjusting kinematic parameters method

Abstract

Force balancing is a very important issue in mechanism design and has only recently been introduced to the design of robotic mechanisms. In this chapter, a force balancing method called adjusting kinematic parameters (AKP) for robotic mechanisms or real-time controllable (RTC) mechanisms is proposed, as opposed to existing force balancing methods, e.g., the counterweights (CW) method. Both the working principle of the AKP method and the design equation are described in detail. A particular implementation of the AKP method for the RTC mechanisms where two pivots on a link are adjustable is presented. After that, a hybrid approach to force balancing of robotic mechanisms is proposed, and this hybrid approach is to combine AKP and counterweights (CW) approaches, called AKPCCWin short. The main motivation of the AKPCCWapproach is thatCWand AKP each has its own advantage and disadvantage, and thus a combined one may strengthen both. This chapter presents the force balancing principles and equations for the AKPCCW approach. Software called ADAMS is employed as a tool for the simulated experiment to verify the effectiveness of the proposed approach. The joint forces and torques are calculated for the trajectory tracking of the RTC mechanisms. The implication of the work to the balancing of mechanisms in general is that many different force balancing methods may be combined based on the hybridization principle proposed in this chapter to become a novel one. Simulation results show that the AKP method and AKPCCW method are consistently better than the CW method in terms of the reduction of the joint forces and the torques in the servomotors, and the smoothing of the fluctuation of the joint force.