Research On Control Of A Bionic Quadruped Robot Based On Co-simulation Technology

The legged robots have better adaptability to the environment,and the parallel leg mechanism has better bearing capacity.Therefore,quadruped robot with parallel leg mechanism have higher practical application value in the field of terrain exploration,material transportation and disaster relief.In this paper,how to control the novel leg parallel mechanism of bionic quadruped robot is studied to improve its motion stability in diagonal gait.The specific research contents are as follows.(1)The dynamic modeling and simulation analysis of the leg planar parallel mechanism of a novel bionic quadruped robot designed by the research group were carried out.In this paper,the planar parallel mechanism of the mechanical leg was described.Meanwhile,on the basis of the geometric relationship between the links,the spatial coordinate system of the planar parallel mechanism of the mechanical legs were established,the kinematics of the parallel mechanism were deduced,and the centroid position,velocity for the links and the linear actuator were obtained;By using Lagrange equation method,the dynamic model of the planar parallel mechanism of the mechanical leg was established,and the display expression equation of the driving force of the upper and lower linear actuators was solved.On the basis,the dynamics was verified by MATALB software and ADAMS software simulation.(2)The stability of the center of mass of quadruped robot was analyzed according to the principle of zero moment(ZMP),the walking characteristics of quadruped and designedfoot trajectory based on the principle of zero impact.The virtual prototype model of quadruped robot was established by using Adams software,and the planned foot trajectory and diagonal gait were simulated to verify the correctness of robot diagonal gait planning and the stability of body center of gravity.(3)The Co-simulation platform of ADAMS virtual prototype technology and MATLAB software was established,and the PID control technology was integrated to improve the stability of the diagonal trot process of the robot.Firstly,the input and output signals should be determined,the PID Co-simulation platform was built,and the input and output communication interface of Adams software was set;Then,the PID controller was built in MATLAB/Simulink,and the interactive data interface between MATLAB and Adams was set to complete the construction of Co-simulation platform.Finally,The planned gait was applied to the Co-simulation platform to verify the correctness and effectiveness of the platform.(4)The fuzzy control theory was added into the Co-simulation model to realize the fuzzy PID control for the robot’s diagonal gait.According to the fuzzy control rules,the fuzzy PID controller was established,and the diagonal gait of quadruped robot was Co-simulated in MATLAB/Simulink environment.By comparing the variation of the trajectory and velocity of the center of mass of quadruped robot in the normal PID control under the diagonal gait,the correctness and effectiveness of the fuzzy PID controller were proved,which lays a foundation for the real prototype control of this novel quadruped bionic robot.