Research On Integrated Control Method Of Automatic Transmission Object In The Loop Test System

It's more and more favored by consumers that the automatic transmission has the advantages of high reliability,smooth shift,operation conveniently and so on.Domestic independent brand manufacturers are vigorously developing automatic transmission.Testing and calibration are essential in the development process of an automatic gearbox.Objiect in the loop test systems can simulate vehicle driving conditions and environment It is not only effectively and accurately testing the automatic transmission,but also can replace some of the vehicle testing and calibration work,which can save development cycle time and cost greatly.The paper combines with the demand of the object in the loop test system in the development of Electric-Mechanical Continuously Variable Transmission(EM-CVT)in an enterprise,focusing on key technologies of integrated control modeling,simulation analysis and verification methods.It is of great theoretical significance and value for engineering for the development and application of object in the loop test system.First of all,the paper studied the operation principle and control method of automatic transmission control system,hardware ring system and test bed control system on the basis of collecting relevant literatures at home and abroad.The scheme of object in the loop test system was proposed by using the high dynamic low inertia motor,CAN bus,LABCAR platform and automatic transmission test bench.Secondly,according to the principle of induction motor and dynamics theory,bench motor model and direct torque control model was established by MATLAB/Simulink and the equivalent inertia and equivalent damping of the rotor and shaft components were calculated.The mechanical structure and automatic control principle of EM-CVT were studied,and the control model of EM-CVT clutch and the ratios control model were established.The whole vehicle dynamics model was simulated by FTP75 cycle.In the 13 start-up and shutdown conditions,the EM-CVT control model could correctly control the clutch combination and separation,and control the CVT transmission ratio.On this basis,the integrated control system simulation platform of the object in the loop test system was builtThirdly,the output characteristics of the engine were simulated by a induction motor using the PID control,the first order lead-lag feedforward control and the compensation correction method respectively.Compared with the results of time domain and frequency domain,the compensation correction method could accurately simulate the torque output characteristics of the engine.Based on the forward model,the speed tracking control method was used to simulate the dynamic load of the rear end of the transmission.It was compared that the electromagnetic torque and rotational speed of the rotor under different inertia.On this basis,the simulation and analysis of the integrated control method for the object in the loop system of the automatic transmission was carried out.The simulation of the actual running condition of the automatic transmission in the vehicle environment was realized.Finally,on the basis of the existing high dynamic transmission test rig,the automatic transmission object in the loop test system was built.The test software is compiled and experiments were carried out.The experimental results were in good agreement with the simulation results.The results showed that the integrated control scheme was effective and feasible,and could accurately simulate the dynamic driving conditions of the automatic transmission in the vehicle environment.