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Abstract

Closed-form forward/reverse position solutions for a 6-degree-offreedom (DoF) parallel mechanism that has some type of nonsymmetric geometry are derived in this study. Particularly, the derived forward-position analysis is applicable to the mechanisms in which three passive joints are constrained to move parallel to the moving plate. Its kinematic and dynamic characteristics are investigated via isotropic index of the Jacobian matrix and isotropic index of the output effective inertia matrix, respectively. From this investigation, it is found that the mechanism has fairly uniform kinematic/dynamic characteristics throughout its workspace. To examine the effectiveness of the proposed 3-PPSP-type mechanism, a prototype is designed, implemented, and tested experimentally under various operating conditions. A simple PID controller is applied to the system, and its joint positions are servo-controlled. The controlled syste