Research On Gait Planning And Foot Force Control Of The Quadruped Robot

This thesis comes from a key project of Heilongjiang about the research of Hybrid Quadruped Robot. Quadruped mobile robot is an important branch of robot. Because of the stronger loading capacity and better stability than biped mobile robot as well as simpler structure than hexapod robot and eight-legged robot, research of quadruped mobile robot has aroused great attention in the world. The paper focuses on the research of gait planning and foot force control problems of the quadruped mobile robot.Gait planning of legged robot is the research hotspots and key issues all through. Legged robot has congenital bionic characteristics, so based on the combination of characteristic analysis of animal gait and our robot structure; the crawl gait similar to reptile is planed. Meanwhile, discontinuous crawl gait and continuous crawl gait of quadruped mobile robot on even road are comparative simulated and analyzed from the aspect of stability margin, walking efficiency and body compliance.Compare with wheeled robot, the legged robot has a prominent advantage which can adapt to uneven pavement. Aim at convex and cave environment, the robot need make gait and posture adjusted to stable walking. This paper focus on ladder-shaped obstacles from the obstacles perception, pose adjustment and swing leg planning aspects to the quadruped robot, thoroughly analyze and simulation, and the capabilities of cross obstacles of the robot is calculated.To maintain quadruped robot scheduled posture on rough terrain and good transition from free space to constraints space, A mix of control methods, position-controlled during a swing phase and force-controlled during its supporting phase is adopted. On the basis of analyzing the force model of the robot, compensate foot force distribution in a virtual suspension model is adopted to amend the deviation of the robot poison and height. Besides, the paper apply force based impedance Control achieve adequate transition from free space to constraints space and force tracking.Finally, this paper quadruped mobile robot experiment to verify the correctness of this theory, which contains continuous crawl gait in even terrain, discontinuous crawl gait in the case existing obstacles and impedance control of single leg.