Research On Precise Control Of Electric-controlled AMT Shift Actuator In Pure Electric Vehicle

Wih the consumption of oil resources and the progress of battery and motor control technology,many enterprises,including Internet companies,have begun to study new energy vehicles dominated by pure electric vehicles.The automotive industry has shown the trend of electrification,intelligence and networking.Electric drive system is one of the core of pure electric vehicle.Compared with the engine,the drive motor has a wide and efficient speed range,which usually needs to be equipped with a two gear transmission to match the power demand of the vehicle.AMT has the advantages of simple and compact structure,high efficiency,etc.The electric control electric shift actuator and the shift motor only need power to complete the shift operation.The electric control electric AMT Suitable for pure electric vehicles.In this paper,the motor transmission direct electric drive system of a drive motor active synchronization is taken as the research carrier,and the key research object is the electric control electric shift actuator.The mechanical accuracy and control performance of the actuator directly affect the shift success and shift quality.This paper aims to shorten the shift interruption time and reduce the shift impact.Combined with the shift process control strategy,the following research is made on the shift actuator:(1)Shift motor and shift actuator analysis and modeling.According to the power transmission route of ball screw gearshift,the mathematical model of BDC is built through the voltage balance and torque balance equation,the force and motion of each component in the transmission process are studied,and the overall motion model of gearshift motor actuator is built,and the response relationship between the motion state of gearshift actuator and the change of motor terminal voltage and gearshift resistance is obtained.(2)The control strategy optimization of driving motor active synchronous shift process.In order to reduce the shift resistance and shift time,a detailed shift process control strategy is developed based on keeping the shift impact less than,including the torque compensation of the active torque reduction of the drive motor in the engagement and separation stage,and the active speed regulation of the drive motor to reduce the collision resistance in the engagement process of the jaw clutch.The model of tooth surface collision and engagement is established by Adams.The influence of speed difference,shifting force and residual torque on shifting resistance is analyzed by simulation.At the same time,the difficulty of shifting caused by insufficient precision of speed regulation and torque regulation control is compensated by increasing shifting force.(3)Research on control strategy of shift actuator.According to the control strategy,the shift actuator control is divided into three stages,the first stage and the third stage need to be completed in the shortest time,at the same time,in order to prevent the impact,it is necessary to ensure the overshoot,and the second stage needs to follow the specified displacement trajectory in order to weaken the secondary impact.(4)Three closed loop controller design.The current loop,speed loop and position loop of the shift actuator are designed.PI control is used in the current loop and speed loop,and PID controller is used in the position loop.Aiming at the problem that PID control parameters are difficult to adjust online,the fuzzy neural network control model of Mamdani structure is built by combining it with fuzzy control and neural network.Based on the fuzzy PID control,the controller Ability to learn.(5)Bench test verification.Firstly,the test bench is calibrated,and the static shift test is completed to verify the effectiveness of the adaptive PID control algorithm of the shift actuator.Then carry out the shift process bench test,and verify the effectiveness of the control strategy optimization by comparing the front and rear shift time and shift impact.