Electronic Throttle Parameter Identification And Design Of Nonlinear Compensation Controller

The rapid development of the automobile industry has brought great convenience to people's travel,but also brought pollution and energy problems.Reducing engine emissions and improving fuel economy are top priorities for internal combustion engine developers.Electronic throttle is a key component to control the intake air flow of the engine.The engine electronic control unit adjusts the opening degree of the electronic throttle disc according to the information such as the position of the accelerator pedal to realize the control of the intake air flow.Finally,the target air-fuel ratio is obtained according to the intake air flow,and then the output torque of the engine is controlled.Therefore,fast and precise control of the throttle opening is very important for engine energy saving and emission reduction.This work takes the Bosch 0280750137 electronic throttle as the research object,builds a mathematical model of the electronic throttle,identifies the model's parameters,designs a model reference adaptive nonlinear three-step controller,and gives an experimental bench under multiple operating conditions.Firstly,build a mathematical model of the electronic throttle and identify the model parameters offline.According to the physical structure and working principle of the electronic throttle,the voltage balance equation of the electronic throttle motor and the torque balance equation of the throttle baffle are established,the nonlinearity of friction,return spring,and gearbox is also analyzed.To identify the electronic throttle parameters,it is necessary to obtain the opening degree and the angular velocity of the electronic throttle valve.This design uses two position sensors measurement scheme to obtain the acquisition electronic throttle opening degree and reduce the measurement noise of the throttle opening degree.Kalman filter is used to obtain smooth electronic throttle angular velocity.Two sensors measurement of throttle opening,smooth angular velocity obtained by Kalman filter,and parallel fuzzy optimization algorithm were used to identify electronic throttle parameters offline and verify the validity of the parameters.Secondly,a model reference adaptive three-step nonlinear controller is designed.There are two major problems with electronic throttle control: the first is non-linearity,including non-linearity of friction,return spring and gearbox.The second is the reliability problem,including parameter changes caused by changes in environmental factors such as temperature and equipment aging.As a result,the initial model parameters used in the design of the model-based controller don't meet the control requirements when the parameters change.In order to solve the above control problems,a model reference adaptive three-step nonlinear controller is built in this design.The thriple-step nonlinear method can compensate the nonlinear structure of the system and ensure the fast response performance of the system.The adaptive compensator is used to estimate and compensate the unmodeled dynamics and improve the tracking accuracy of the system.Finally,an electronic throttle experimental bench was built and the effectiveness of the controller was verified.This design builds an experimental bench based on MATLAB/dSPACE,including electronic throttle,computer host,dSPACE,12 V vehicle power supply,PCB board.The PCB board contains an H-bridge throttle motor driver chip and a 12V/5V power conversion chip for powering the throttle position sensor.Considering that the expected opening of the electronic throttle may be transient,slow,small,or large in actual applications,the design uses classic sine,step,and ramp signals as reference signals to verify the tracking performance of the controller.In order to verify the effectiveness of the controller when the air impacts the throttle baffle,the design verifies the control performance of the controller when the engine is rotating.Bench test results show that the model reference adaptive non-linear triple-step method controller proposed in this design has fast and stable tracking performance and meets the control system design requirements.This project was completed under the funding of the National Natural Science Foundation of China's Youth Science Foundation Project(61703179)"Optimization and Control of the Combustion Process of Internal Combustion Engines" and Jilin Development and Reform Commission Project(2019C036-4)"Development and Industrialization Demonstration of Electronic Controller of Fuel Cell Air Supply System".