Multi-mode Joint Motion Control System For High Efficiency Biped Walking Robot

Based on the prototype of biped walking robot driven by motor developed by the laboratory,a joint motion control system is designed in this paper.Firstly,the robot model is introduced.At the aspect of the theoretical basis of robot design,two-point walking theory is introduced.The mechanical structure and joint parameters of the robot are listed.The foundation for the model compensation through D-H matrix is built.The motor model is built.The three-dimensional simulation model of the robot through MATLAB/Simulink is built.Secondly,according to the demand of multi-mode control of robot joints,the position control and force control algorithm of robot joints are simulated.The idea of distributed control is adopted in both position control and force control.In other words,each joint is controlled separately.The model compensation based Active Disturbance Rejection Control(ADRC)algorithm is used in position control.The simulation comparison with the model compensation based PID control algorithm shows its superiority.Force control mainly provides a constant pedal force to the robot through the ankle,and the relevant parameters are determined by simulation.Then,the hardware and software design of the joint control system is introduced.Hardware is mainly divided into power system board,master control board of joint slave station,3-DOF driving motherboard and motor driver.The specific design scheme is introduced in detail.At the Software aspect,each task based on FreeRTOS real-time operating system is designed.The joint driver mainly realizes the current loop control and CAN communication.After Simulink simulation and verification,the algorithm is designed adopted by the model-based design concept and the input-output interface of the algorithm part is defined to generate embedded code directly for actual robot motion control.Finally,an experimental platform is built to carry out position control and force control experiments on the robot.Position control experiments mainly carry out single-degree-of-freedom manipulator experiments and joint linkage experiments to verify the stability and control accuracy of the control algorithm.Force control experiments mainly test the relationship between current and the actual strength pedal force of the robot.The experimental results show that both position control and force control can satisfy the control requirements of the robot joint system.