KINEMATIC ANALYSIS OF A GENERAL DOUBLE-TRIPOD PARALLEL MANIPULATOR

The kinematics of a general double-tripod manipulator is presented. Th e double tripod manipulator is based on a spatial three-degrees-of-fre edom (3-DOF) parallel mechanism. The device possesses a moving platfor m, a fixed platform, and three legs. Each leg comprises kinematically similar rotary, spherical, and rotary joints. The kinematic model of t he mechanism used here consists of a generalized, non-reflective mecha nism. The mobility of the mechanism is examined, and solutions to the forward and inverse kinematics problems are presented. It is also show n that special geometries of the mechanism result in closed-form solut ions for both the forward and inverse kinematics, Numerical results ar e presented for the general case and also for the simplified case, and algorithm speed is examined. (C) 1998 Elsevier Science Ltd. All right s-reserved.