Analysis And Test On Dynamic Characteristics Of Quadruped Robot Leg

The leg performance and load capacity of a quadruped robot have a direct impact on the movement of the whole robot,the factors that affect the leg performance mainly include the structural design of the single-leg,the design of control strategy and servo control scheme.In view of the current domestic technical research on the single-leg dynamic characteristics of most quadruped robots was not mature enough,this paper designed an electrically driven quadruped robot,the leg control strategy and the servo control system of single-leg were established,the dynamic motion performance and static load-bearing performance of the robot were explored.The main contents were as follows:Firstly,the characteristics and development history of electric-driven quadruped robots were studied,the core technical problems at present were concluded,and the research contents and ways of the quadrupeds were determined.Then according to the bionic mechanism of the legs and body of the quadruped,this paper designed a structural model of a quadruped robot with multiple degrees of freedom.By establishing the D-H model of the quadruped robot's single leg and the 3-DOF single leg coordinate system,the forward and inverse kinematics of the single leg and the motion space of the single leg of the robot were solved,and the theoretical motion trajectory of the robot's foot was planned.Secondly,the selected brushless DC motor was modeled,motor's model was built and its transfer function was calculated,the control system adopts the double closed-loop control of current loop PI and position loop PD.The control block diagram of the leg was built,the simulation analysis was solved,and the dynamic characteristics of the leg joints were analyzed by drawing the Bode diagram of the current loop and the position loop,and the control bandwidth of the current loop and the position loop was solved.In addition,this paper proposes a single-legged control strategy and builds a single-legged control system framework,finishing the selection of each sensor and data acquisition,finishing the design of the actuate system control project.The CAN communication method was used to complete the robot signal sending and receiving,and the parameters of the single-leg drive were set and the communication test was carried out.Finally,the experimental platform of the quadruped robot was assembled and tested,the motion characteristics of the quadruped robot were verified by single joint dynamic characteristics test,single leg foot force loading test,single leg swing test and the whole quadruped robot test.The experimental results show that in terms of the mechanical structure and control strategy of the quadruped robot designed in this paper meet the requirements of load and motion performance.