Actuator Parameters Matching Research Of Hydraulic Quadruped Robot Based On Joint Trajectory

With the development of robot research,quadruped robots driven by hydraulic pressure are gradually being used in military,exploration,rescue and other complex field environments,outdoor working environment puts forward higher requirements for the endurance and stability of robots.As a joint driving unit of hydraulic quadruped robot,the performance of electro-hydraulic servo actuator will directly affect the motion characteristics of the robot.Therefore,the electro-hydraulic servo actuator with high efficiency and high power density is the premise and foundation to ensure the long-term stable operation of the robot outdoors.To this end,this paper will be based on the joint trajectory of a hydraulic quadruped robot in Trot gait,the method of optimal load matching is used to study the load matching parameters of robot actuators.Establishing a three-dimensional model of a robot by analyzing multiple sets of topologies.Kinematics model of robot was established by D-H method,the forward and inverse kinematics question of the robot foot to the center of fuselage mass was analyzed,Newton-lagrange method was used to analyze the leg dynamics of the robot.It provides theoretical basis for subsequent gait planning and dynamics simulation.The foot workspace of the robot is established,The Trot gait of the robot was planned by using a foot trajectory planning method based on a new cycloid.The displacement,velocity and acceleration of the foot trajectory in a two-dimensional plane was analyzed,the rationality of the algorithm based on cycloid was verified.Virtual prototype technology based on Adams was adopted,trot gait simulation of robot was carried out,finally,the joint trajectory of Trot gait was obtained.The structure of electro-hydraulic servo actuator was analyzed,the model parameters of displacement and force sensor was determined.The rotation space of the robot leg joint was transformed into the stretching space of the actuator,The load trajectory of the actuator was obtained.The multi-group load matching model of the actuator was established by changing the output characteristic curve,finally,the optimal load matching parameters of the actuator were determined according to the matching rules.AMEsim-matlab joint simulation platform was set up,hydraulic system simulation was carried out for multiple sets of matching parameters,the simulation results show that the actuator operating efficiency is the highest under the optimal matching parameters.the validity of the actuator load matching method based on joint trajectory was verified.Based on the above theory and simulation research,experimental platform of hydraulic quadruped robot prototype was built by combining the optimal matching parameters of actuator.An experimental study on Trot gait of robot was carried out,the experimental results further verify the effectiveness of the proposed scheme.