Combustion Engine Test Bed System Identification Under the Presence of Cyclic Disturbances.

In this article, a new approach for combustion engine test bed system identification is presented. Modern engine test beds are used to reduce development time by utilizing them for hardware-in-the-loop tests. For highly accurate and close-to-reality tests, model-based controllers are deployed, which rely on precise models of the test bed. Hereby, the main challenge is the unknown, cyclic disturbance of the engine due to compression and combustion of the air-fuel mixture. These disturbances also occur when the throttle is kept at zero and have a big impact on the measurements. Therefore, parameter estimation is strongly impeded. A method for dealing with these disturbances and embed them into the identification procedure in a two-step fashion is presented in this contribution. Further advantages of this new approach are that a physical model is obtained, but prior knowledge of parameters is not necessary. Moreover, disassembling of the test bed to perform separate parameter estimation is not needed and hence, the time consumption of the procedure is kept low. Experimental results on a 4-cylinder diesel engine test bed prove the feasibility and effectiveness of the proposed concepts. [ABSTRACT FROM AUTHOR]