Research On Gait Planning And Experiment Of A Novel Quadruped Walking Robot

On earth,more than 50% of the land is mountainous and hilly and other complex terrain,human and animals gradually adapt to this environment with the constant evolution,and the legged robot which has the characteristics of high flexibility and adaptability like human and animals is more adapt to the complex environment than the tracked robot and wheeled robot.The quadruped robot not only move flexibly but also has high comprehensive performance and research value whether it is from stability and load capacity or the difficulty of robot control.The quadruped robot mostly adopts serial or parallel leg mechanism.The performance of the quadruped robot is affected due to the limitation of their own institutions,so the research and development of the series parallel hybrid mechanism with both advantages emerges as the times require.Gait planning is the foundation of quadruped robot to walk stably and is the premise of robot control.It is also an important research of quadruped robot.A novel serial parallel hybrid quadruped walking robot is taken as the research platform,and the kinematics analysis of the forward and inverse position kinematics,the gait planning and the experiments are carried out in this paper.The main research work is as follows:The mechanism of a novel series parallel hybrid quadruped robot is described and its characteristics are analyzed.The forward and inverse position kinematics model of the hybrid leg is established.The kinematics inverse solution model of the quadruped walking robot is also solved and the correctness of the inverse solution is verified by simulation.On this basis,the trajectory planning problem of the serial parallel hybrid leg is studied.Aiming at the impact phenomenon in the trajectory planning of the robot's foot,a new algorithm based on high order polynomial is presented.The algorithm not only can eliminate impact between the foot end of the robot and the ground at the beginning and the stopping but also can reduce the jerking phenomenon during the movement which has the features of high order polynomial continuity.In addition,the trajectory of the supporting phase and the swing phase of the quadruped robot is planned and the correctness of the method is verified in the following simulation.Gait planning is the basis of robot control.The robot's gait can be divided into static and dynamic gait according to duty cycle.In this paper,a typical gait of walk is used to complete the static gait planning of quadruped walking robot.The gait planning of walk is carried out using non impact trajectory planning algorithm.The foot end equations of quadruped robot are established and the driving parameters of each leg are calculated by the inverse kinematics model.The walk gait of quadruped robot is simulated by ADAMS and the results show that the quadruped robot can complete the motion of walk gait.For the quadruped robot's dynamic gait planning,the typical trot gait is used as the dynamic gait.The trot gait of quadruped robot is planned using the non impact trajectory planning algorithm,the foot end equation is established and the driving parameters of each leg are solved.The simulation experiment of trot gait shows that it can walk on the flat ground.However,there are some problems of the hind leg dragging in the process of moving.The supporting legs of the robot are re-planning aiming at the problem so the gravity position of the robot is changed during the movement.The results show that: the problem of the hind leg dragging of the trot gait is improved obviously and the quadruped robot can complete the trot gait motion..Finally,the quadruped robot test platform is developed,including the single leg and the whole platform.Based on the Windows platform,the control system of the single leg and the whole machine are designed by C#.The hardware of the whole control system adopts PC and Trio motion controller.After the development of the system and test platform,the experimental research on the hybrid legs and the robot is carried out and it show that the movement can be completed.