The Dynamic Model And Gait Simulation Of A Wheel-legged Robot—Rolling-Wolf

High-performance mobile robot is always a hot spot of the research of biomimetic robots. This paper firstly analyzes the current research status of quadruped robot and wheel-legged robot from these aspects: structure design, motion planning and feedback control. The features of several popular kinds of robots are as follows: legged robot has good terrain adaptability, but complex structure and comparatively low running speed; Wheel robot can run smoothly and can be easily controlled, but poor adaptability limits its working space; while wheel-legged robot combines the advantages of both legged robot and wheel robot, therefore, the research of wheel-legged robot has become the research object of scholars at home and abroad.The main part of this paper conducts research of a new kind of wheel-legged robot——Rolling-Wolf which is composed of structure body, thigh, calf, driving motors, slider and wheels. Based on the prototype, main research work is conducted as follows:①We build up forward and inverse robot kinematic model including pitch angle and roll angle with Euler angle and homogenous transformation. And then, we calculate the velocity Jacobian matrix which can represent the relation between joint motion and foot motion based on robot’s different motion transformation.②Referred to computed kinematics, we plan a kind of gait which is based on parabolic transited linear interpolation method for Rolling-Wolf. The gait not only satisfies static stability principle, but also produces no rigid impact on the mechanism. Then according to preset gait parameters, the foot trajectory curve and the sample points collection in realized through Matlab.③We establish the dynamic model of Rolling-Wolf by using the Lagrange equation with selecting the angle among body, thigh and calf as the generalized coordinates. At the same time, the contact force between wheel and ground is also considered. Therefore, the built dynamic model has very high versatility.④We conduct crawl gait through flat ground simulation in ADAMS. And in this paper, we mainly introduce the methods of setting simulate parameters and slider driving function which is calculated based on inverse kinematics. After simulation, we detect and analyze the motion of the centroid and the ipsilateral thigh sliders of the body. And finally, we verify the validity of the computed kinematics through simulation.