Development of Real Time Inlet Air Model of Diesel Engine Based on ‘V’ Cycle Mode

Abstract

In recent years, more attentions are paid to environment protection and energy crisis in China so demands are being put on improving fuel economy and low emissions. On the other hand, many people in the automotive community never give up looking for innovative methods to meet the demands. Model-based control and diagnosis technology is very potential and now has been used in many aspects. Particularly, Model-based methods are very popular in development of Engine control unit and some relevant developing tools also arise such as MATLAB/Simulink, dSPACE. A standard development flow called ‘V’ cycle is refined. In order to improve control efficiency and extend the diagnostic methods of fuel injection and after treatment equipments, It needs to get the accurate amount of fresh air charged into diesel cylinder which greatly influences engine combustion process. According to the popular “V” development mode, we build a real time model of fresh air based on Simulink tool and realize the off-line simulation, rapid prototype validation, data scaled, code auto generation, and engine bench test. Real engine test results indicate that the model can satisfy the real time and accuracy requirements completely. This chapter describes the creation and validation of a control-oriented diesel inlet model and doesn’t consider the effect of exhausted air which will no doubt increase the complexity and decrease the real time efficiency, but can extend the model used scope greatly. During construction of the model, We not only consider the dynamic parameters that influence the amount of fresh air such as volumetric efficiency, temperature and pressure of the inlet air, but also consider the difference between static test standards and dynamic running states.

F2012-A05-010