Overall Inverse Kinematics Analysis of Parallel Robot Leg for Rescue Based on Rodrigues Parameters

A new method to describe the position-stance of parallel robot leg was proposed based on the Rodrigues theory. Comparing with others methods, the kinematic model with Rodrigues parameters has the advantages including least computational parameters, no trigonometric function calculation and convenient real-time control. The model of the inverse kinematics was established and the inverse solutions of the position-stance were obtained by analyzing the topologic structure of the parallel robot leg with 3-RPS limb. According to the vectors of the manipulator, the velocity and acceleration models of moving platform, limbs and end-effector were deduced. By comparing with the normal walking gait of a human subject, the end-point trajectory of the parallel robot leg was better programmed. The experiment results showed the structure characteristics of the parallel robot leg and validated the model of the inverse kinematics. It was concluded that the parallel robot leg can fulfil the kinematic demand in the unconfigurable environment.