Study On Central Pattern Generator Based Gait Generation Approach Of Mobile Robots

With the development of science and technology,the application of robots in the society is becoming more and more usual.Whether it is earthquake rescue,military search,or medical assistance,there is an increasing demand for mobile robots in daily life.How to control the robot to achieve different gaits? how to improve the application of the robot in the real life? These questions has become popular research topics.In this paper,a quadruped robot and a close-chained rolling robot are selected as the research objects.the control methods of the gaits for the two robots are studied based on the CPG(Central Pattern Generator).the simulation and experimental verification are completed.The main research work are as follows:The bionics literature on quadrupeds movements are investigated.the motions of the quadrupeds are analyzed.the relationship between gait parameters and movement speed is analyzed.the theory and methods of robotics is used to analyze the cheetah feet's trajectories in high-speed locomotion.the bionic laws of the quadruped movements are summarized and applied to engineering practice.The hierarchical architecture of the quadruped robot bionic control method is constructed,in which the high-level center is used to determine the relationship between the speed and gait parameters.The phase oscillator is selected as the CPG oscillator model to achieve coordination between the quadruped robot's limb movements.the Bezier curves and particle swarm optimization(PSO)algorithms are used to achieve foot-end trajectory planning,which determine the coordination relationship among the joints in a limb of the quadruped robot.At the bottom of the controller architecture,VMC(Virtual Model Control)is used to adjust the attitude of the robot's torso to achieve stable locomotion,and PD(Proportional Derivative)controller is used to convert the joint angle into torque.The combination of ODE(Open Dynamics Engine)and Open GL(Open Graphics Library)are used to build a quadruped robot simulation platform to conduct walk and trot,and gait transition motion simulations.The foot trajectories,joint angles,and joint torques are analyzed.The effectiveness of the bionic control method of the quadruped robot is verified.The CPG control method is applied to control a close-chained robot.Based on the spider-like robot,the kinematic modeling of the rolling gait is completed.the parameters of the CPG model of kinematic rolling and dynamic rolling are determined.In addition,torsion springs are attached to the passive joints of the spider-like robot,aiming to make use of its energy storage capacity to compensate the insufficient driving torques.the MATLAB/Simulink and ADAMS co-simulations is used to realize rolling locomotion of the spider-like robot.Modularization and safety transformation of the original prototype is accomplished.the host computer interface software is written based on Qt.the CPG control algorithm is wrote into the servo control card.Finally,the rolling motion experiments of the spider-like robot are completed,which verifies the feasibility of the control method and the prototype structure.