Flexible Ankle Motion Control Of Efficient Biped Walking Robot

This paper designs a flexible ankle joint for a 23-degree-of-freedom motor-driven biped walking robot,and designs its joint motion controller.First of all,the robot model and the main walking idea of the laboratory is introduced:two-point walking theory.This paper introduces the mechanical structure parameters of the robot,divides the robot control system into three categories according to the structural characteristics,and establishes the joint position control based on the model in each control system.Secondly,the flexible ankle joint control algorithm is designed according to the robot walking and standing balance requirements,including position control and force control.Rolling position control is designed based on the singular perturbation theory to design a fast and slow two-dimensional controller,and compare it with the one-dimensional PID controller,which reflects its superiority.Rolling force control is mainly designed for friction force identification method for feedforward compensation.Pitch position control adopts high-gain PID controller,designed an admittance control method based on the effective position control.Then,the hardware and software design process of the robot joint controller is introduced.The hardware system includes the design of sensor installation,sensor acquisition board and the driver board for the lower leg.The software system includes designs the communication program for the master and slaves based on Ether Cat,the control program of the slaves and the sensor acquisition board and the drive motherboard based on CAN.Design the communication program to connect the attitude sensor and the sensor acquisition board based on the SPI bus.Using matlab to make embedded control code.Finally,build an experimental environment,apply the above software and hardware to the robot,and match the angle definition in the program with the robot angle definition.Design the force sensor calibration experiment.Design the force and position control experiment of ankle joint based on the successful communication verification test and sensor verification.Adjust the control parameters to make the system adjustment time and steady-state error meet the control requirements.Later,the robot standing balance experiment was designed,which finally proved that the various communication systems of the robot coordinated operation and the design algorithm was effective and reliable.