A New Simulation Step Towards Virtual Bench Through the Challenging Case of Two-Stage Turbocharger Diesel Engine Control Design 2008-01-0355

Improving the simulation support in engine development projects is a very attractive way to reduce cost and duration of such projects while increasing the deliverable quality. Thanks to advanced models and specific know-how, this paper presents a new step which consists in the use of simulation as a virtual engine bench for control design when the real engine is not yet available.

In a first part, the goals and requirements of such a simulation approach are described. Then, the specific case of a two-stage turbocharger Diesel engine application from an IFP-RENAULT control design study is presented. At first, the virtual bench design is detailed from a methodological point of view. The engine simulator development and its use as a virtual control bench are then described. The control strategies design is presented, but also the anticipation of potential limitations such as inadequate turbocharger behavior or system failure detection management. The last part presents the simulator improvement once the real engine is available on the test bed. The a posteriori validation shows a good agreement between simulation and experiment, which confirms that the simulation based control strategies are adapted to the real engine. Finally, according to the engine test bed measurements, the final simulator calibration is described and the simulation's continuous and efficient support, in conjunction with the tests on the bench, is also presented.

Therefore, this paper demonstrates that the simulation approach is now accurate enough to be of great interest, even in the very early stages of such a development project and how relevant the use of such a virtual bench for control design purposes is, especially with the challenging application of a two-stage turbocharger Diesel engine.