Increasing demands for more efficient engines and stricter legislations on exhaust emissions require more accurate control of the engine operating parameters. This control is mostly based on numerous physical sensors which play a vital role in the on-board condition monitoring of the engine. Nevertheless, physical sensors in combination with the need of accurate control increase the complexity and the cost of the engine. Virtual sensors are one of the methods that can be used to actively monitor various operating parameters of the engine, reducing both the complexity and the production cost. In the current study, a virtual sensor that is based on compressible flow modeling is developed in order to estimate the pressures close to the cylinder inlet ports, based only on the pressure signal of a single standard pressure sensor in the intake manifold.
A virtual sensor approach is presented and thoroughly explained and is evaluated in terms of accuracy, computational cost and feasibility. The virtual sensor evaluation is based on an experimental study on the intake manifold of a heavy-duty diesel engine. The experimental results are also used for validation of a simulation model employed to investigate the behavior of the virtual sensor approach on pressure estimation in the exhaust manifold. The virtual sensor provides very promising results. It is shown to be capable of use for real-time cylinder inlet port pressure estimation.
Sotirios Tsironas, Ola Stenlaas, Magnus Apell, Andreas Cronhjort
Scania CV AB, KTH Royal Institute of Technology