Study On Hydrostatic Steering System Of Dual Power Flow Transmission Tracked Vehicle Based On Unmanned System

As the continuous development of self-driving technology,unmanned tracked vehicles gradually become one of the key projects of tracked equipment in every country.For the horizontal and vertical motion control of an unmanned tracked vehicle,researches on the unmanned tracked vehicle’s steering system and self-steering control policy are always the focused project,due to the varied steering mechanism and transmission.For the zero-differential dual power flow transmission with hydrostatic steering system,this thesis carried out a transformation scheme about hydrostatic self-steering system based on unmanned tracked vehicle.This thesis designed a self-steering scheme of hydrostatic steering system to achieve the self-steering of unmanned tracked vehicle.Firstly,the kinematics of the tracked vehicle and characteristic of hydrostatic system are researched,and this paper analyzed the mathematical model of the system to build a simulation model of the zero differential double flow transmission with hydrostatic steering system using the MATLAB/Simulink tools.The simulation model has built a foundation of research on self-steering system and control policy.Secondly,this paper proposed the transformation program and control policy of hydrostatic self-steering system based on unmanned tracked vehicle.Using the variable displacement pump with electrical displacement control for hydrostatic steering system,the remote control system would be established.And according to the characteristics of hydrostatic steering system and the self-steering control demands,the control system of self-steering control system of hydrostatic steering was designed,which including receiving the steering goals,unmanned control and feedback system.Thirdly,the vertical characteristics and the performance of dual-flow transmission system were studied according to the actual driving test data.And the parameters of vertical driving characteristics would be used in the simulation of self-steering control policy.Finally,the self-steering control policy was presented by using the simulation and vertical driving characteristics to define the relationships between the expected steering radiuses and steering control parameters under various self-driving conditions.The performance of self-steering would be improved by using the PID control algorithm based on BP neural network for the steering radius,considering the different road conditions.The simulation results illustrated that self-steering control policy is in line with corresponding demands and it could improve the stability and robustness of hydrostatic self-steering system of the tracked vehicle.