Research On Dynamic Model Of Electronic Control Engine

At present,the vehicle system is developing in the direction of electronic and intelligent,and the impact of electronic control systems on vehicles is increasing.Among them,the engine is also transformed from a traditional mechanical carburetor engine to an electronically controlled electronic throttle engine.The engine management system has an important influence on the output characteristics of the engine,and the map-based engine model can no longer meet the requirements of accurate simulation.At the same time,for the calibration of the vehicle electronic control system,it is necessary to wait for the trial production of the actual vehicle to complete the final calibration.The entire development process has a long period and high costs.Thus,this requires a virtual test simulation platform.Based on the vehicle dynamics model with an electronic control system,the calibration of the electronic control system was brought to the early stage of development,shortening the development period and saving costs.Therefore,this paper establishes a dynamic model of electronic control engine,which compensates for the lack of map-based engine model and improves the simulation accuracy of the model itself.At the same time,the model takes into account the coordinated control with other ECUs,making it possible to communicate with each other through ECUs,thereby providing the basis for a virtual test simulation platform.From this study,the following studies were conducted:1.This paper proposes an EMS function model,which aims at the deficiencies of the map-based engine model,considers factors such as driver demand torque,torque limit,torque loss,idle speed control and torque coordination,and establishes a corresponding functional module based on this.It realizes the functions and interfaces of the actual engine management system,and provides a basis for the establishment of an electronically controlled engine dynamics model.2.For the problem that the EMS function model cannot directly connect with the map-based engine model,this paper analyzes it and proposes an improvement plan as follows: Firstly,a combustion pressure model based on dynamometer charts was established.Based on the dynamometer charts constructed by the throttle,crankshaft speed,crank angle and cylinder combustion pressure,and taking into account the correction of ignition advance angle,the relationship between throttle,ignition advance angle and cylinder pressure was established.Secondly,the mechanical dynamics model of the engine was established.Through the dynamic analysis of the crankshaft connecting rod mechanism and the engine crankshaft,the crankshaft movement status is obtained.Thus,the connection of the EMS function model is realized and the modeling of the electronically controlled engine dynamics model is completed.3.The established dynamic model of electronic control engine is integrated into the existing ASCL vehicle dynamics model of the research group.Firstly,the verification of the vehicle field test was conducted,and the model was compared with the vehicle field test and the original ASCL model data.The results show that this model is closer to the vehicle field test data than the original model in terms of throttle,engine speed,and longitudinal acceleration.Secondly,the integrated model is embedded into the driving simulator,and special operating conditions such as Tip in/Tip out,idle speed,low speed,high speed and torque coordination are performed.The results show that the model has improved driving ability compared with the original model,and can coordinate with other ECUs at the same time,providing a basis for the establishment of a virtual test simulation platform.