Research On Robotic Leg System Motion Control Based On Dynamics Compensation

The hydraulic foot bionic robot has strong motion ability and load capacity in a complex environment,and has great military and civilian potential.It is a hot topic at home and abroad.In the face of a complex environment,the robot requires a certain degree of flexibility in the legs of the robot to ensure the stability of the robot's movement,and the dynamic characteristics of the robot's legs during the movement will adversely affect the accuracy of the leg's compliant control.To ensure high-precision compliance control,it is necessary to perform dynamic compensation control.This article aims at the robot leg hydraulic drive system,adopts dynamic compensation control method(including gravity compensation control and inertial force compensation control),and aims to improve the motion control and suppleness control accuracy of the robot leg.The main research work includes:(1)Robotic leg system mathematical modeling.In order to ensure the desired impedance characteristics and motion control characteristics during robot leg motion,forcebased impedance control method is used to achieve the robot leg motion control.Based on the kinematics and statics theory of the robot,the kinematics forward and inverse kinematics and the static and inverse kinematics expressions of the robot's foot-to-joint are established.Based on the deduced kinematics and statics expressions,a force-based impedance control method was used to establish a mathematical model of the robot leg hydraulic drive system,and an overall simulation model of the robot leg system was established.(2)Robotic leg system dynamics compensation control simulation analysis.In order to reduce the influence of robotic leg's gravity and inertial forces on the control performance of the robot's leg,the robot dynamics theory was used to derive the mathematical expressions of the gravity and inertial forces of the robot's legs.The influence of robotic leg and inertial forces on the accuracy of foot-end motion control was analyzed,and a motion control method based on gravity and inertial force compensation was designed.The robot leg system simulation model was used to study the compensation effect of dynamic compensation control method.(3)Robotic leg system dynamics compensation control experimental study.Based on the deduced dynamic formula,the constant number of dynamic equations is separated and the experimental identification is performed.Using the robot single-leg test bench,a dynamic compensation control method was used to experimentally verify the compensation effect of the dynamic compensation control method under various operating conditions.(4)Robotic leg system motion controller design and experimental testing.Take DSP as the core control chip,design the controller's acquisition,control and Ethernet communication module;adopt the model-based design method,design Simulink's automatic code generation DSP driver module,develop the host computer debugging interface based on Labview software environment,and conduct experiments test.