Motion Characteristic Analysis Of A Variable Tracked Mobile Robot

This paper presents a Variable Parallelogram Tracked Mobile Robot (VPTMR) based on the parallelogram deformable mechanism. VPTMR is mainly made up of two symmetrically arranged parallelogram mechanisms, which consists of a main track module, two arm-swing tracked modules and a body module. VPTMR can move in three modes such as wheeled, tracked and legged movement mode to adapt to complex environments.The motion analysis and planning in the process of robot climbing a step have been studied. Kinemics model has been established to analyze the relation between CG and lower arm posture. To keep CG lowest, movement posture of this robot during the process of obstacle-crossing is optimized. According to the optimal CG trajectory continuous actuation is fitted, which is fundamental input for follow-up dynamics analysis.Dynamic model of VPTMR climbing a step is established by using Newton Euler method in three phases. Based on dynamics analysis of the whole process of crossing a step and kinemics equations, the driving torques of crossing a step for VPTMR are obtained. And the stability of the robot is also analyzed.To verify the correctness of above analysis, simulation and experiment are carried out. The result indicates that the motion planning is right and optimized movement posture is efficient. The change rule of driving torque is obtained through simulation for control and the excellent stability of the robot is guaranteed.