Challenging the Vision of Calibration-Free Diesel Engine Development by means of Model-based Control and Automatic Optimization

Authors

Dr. T. Fukuma, S. Nakayama, Y. Harada, A. Matsunaga, Toyota Motor Corporation, Shizuoka, Japan

Year

2004

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 566

Summary

Modern diesel engines with sophisticated electronic control systems are required to satisfy many constraints such as NOx, PM, engine noise and smoke visibility, while keeping low fuel consumption and good driveability. As there are a large number of ECU calibration parameters, an intelligent engine control methodology associated with an efficient calibration method is indispensable in order to enhance development speed and guarantee the vehicle performance in the market. The approach in which a model-based control compensates dynamic performance differences from a multi-parameter steady state optimization with experimental knowledge and statistical techniques has shown that calibration-free development of diesel engines may be possible in the near future. As an example, this paper describes the achievement of NOx emissions requirements by this approach. NOx has been found to be a particularly important parameter in overall optimization because of the trade-off with constraints and set point flexibility. After optimizing overall constraints by varying local NOx set points in steady state operation, the on-board intake oxygen concentration EGR control dynamically guarantees that the vehicle achieves a NOx calibration-free condition. Taking EGR re-circulation delay into consideration, the intake oxygen mass can also be precisely estimated. This means that the dynamic vehicle response can be efficiently optimized, thereby satisfying the smoke visibility requirements.

Order Members Login