Power Flow Analysis Of The Transmission System And Steering Control Strategy Of Dual Motor Coupling Driving Tracked Vehicle

With the rapid development of the national economy and the military,the market demand of tracked vehicle continues to grow.Under the influnence of technological innovations in electric vehicles and hybrid vehicles,electrification has become the future direction of tracked vehicles.At present,the main drive system of the electric drive tracked vehicle is the independent drive scheme of dual motors.However,the transmission scheme has obvious shortages in terms of the power utilization of the motor and the energy recovery during the steering.This paper is based on the project "Overall Performance Design Method and Verification of Electromechanical Composite Transmission".Based on the proposed dual motor drive drive scheme,the following research has been carried out as follow.(1)The power flow and efficiency of the transmission system under different steering radii are analyzed.In order to fully reveal the power flow of the transmission system and the transmission efficiency,the bond graph model of the double planetary coupling mechanism is established.According to the criterion of the power flow,six kinds of power flow of the transmission system in the different working conditions are obtained.Based on the power flow,a new calculation method of meshing efficiency of planetary gear train using bond graph theory is proposed.The efficiency of the transmission system is obtained based on the calculation method.The research shows that because of the existence of the coupling mechanism,the power demand of both sides of the driving motor can be obviously reduced,and the gear meshing efficiency of the transmission system is relatively high.(2)A dual motor driving tracked vehicle simulation model based on MATLAB/ simulink is established.By analyzing the requirements of drive system,the permanent magnet synchronous motor based on space vector control is chose and the drive system model is established.Based on bond graph theory,the state equation of the transmission system is obtained and then the transmission system model is established.According to the dynamics and kinematics of tracked vehicle,a dynamic module of tracked vehicle based on sliding is established.(3)Based on the comparison and analysis of the steering control schemes for tracked vehicles,a comprehensive control strategy for tracked vehicles with dual motor coupling is proposed.The driver input signal is defined and analyzed,and the steering control strategy of tracked vehicle is designed.Simulation research is made on constant steering,deceleration steering and speed up steering,which show that the constant speed steering is more suitable for the coupled drive tracked vehicle.(4)Through the simulation analysis of the two conditions of acceleration and steering,the correctness of the model is verified.By comparing and analyzing,it is concluded that the dual motor coupling drive scheme is obviously better than the dual motor independent drive scheme.The correctness of model and power flow analysis is verified by simulation of tracked vehicles under different steering conditions.The influence of skid and slip on the steering radius and the stability of straight track are analyzed.