Actuator Load Matching And Co-Simulation Research Of Hydraulic Hexapod Robot

With the continuous development of robotics and biomimetic fields,large hydraulic bionic Hexapod robot is widely used in military,civilian,disaster relief,entertainment and other fields.So it puts forward higher requirements for the performance of Hexapod robot.As the driving unit of each joint of the hexapod robot,the performance of electro-hydraulic servo actuator determines that the hexapod robot can complete various working conditions and ensure the stability and energy saving of the system.Therefore,based on the joint motion analysis of the hexapod robot under various working conditions,this paper will conduct in-depth load matching research on its actuator,and build a joint simulation and experiment platform to complete the simulation and experimental verification of load matching.The mechanical mechanism and hydraulic system of the hexapod robot are modeled accurately.In this paper,the structure of the imitation insect and the leg length ratio parameters are determined,and the 3D modeling of the whole machine is completed.In this paper,a valve controlled asymmetric cylinder hydraulic servo system is designed,a mathematical model considering the movement direction of the hydraulic cylinder is established,the transfer function of the valve controlled asymmetric cylinder is deduced,and the pressure characteristics of the valve controlled asymmetric cylinder are analyzed through the mathematical model,which provides a theoretical basis for the simulation of the hydraulic system.The low impact foot trajectory model,kinematics mathematical model and ADAMS dynamic model are established.On this basis,the gait simulation calculation is carried out for the hexapod robot walking on the ground,crossing obstacles and walking on the slope,and the joint trajectory model of the hexapod robot is obtained and analyzed,which provides a data model for load matching.Based on the joint trajectory model under various working conditions,the minimum requirements of the power actuator are determined.Based on the transformation model of joint space and drive space,the load trajectory model of the hydraulic bionic hexapod robot was established.Finally,the load matching model of each power mechanism is completed by combining the optimal load matching method,and then the matching parameters of the power mechanism are determined.According to the load matching of the power mechanism,the co-simulation model based on AMESim and ADAMS was established.The low impact foot trajectory model were analyzed and verified.The throttling loss of the hydraulic system is calculated by the pressure and flow curve of the hydraulic cylinder.Finally,it is verified that the load matching of the dynamic mechanism can improve the system efficiency to some extent on the premise of satisfying the basic motion of the hexapod robot.Finally,according to the model of the experimental prototype of the large hydraulic bionic hexapod robot,the following characteristic curves of the hydraulic cylinder of the hexapod robot under various working conditions are obtained,which verifies the correctness of the load matching again.