Observer Design for Exhaust Manifold Pressure in Turbocharged SI Engines
Hassani Monir, Vahid | 2013
- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 45232 (08)
- University: Sharif University of Technology
- Department: Mechanical Engineering
- Advisor(s): Alasty, Aria; Vossoughi, Gholamreza
- Nowadays, fuel optimum used in engines is an important matter. To achieve this aim, we need to tune engine. The big companies have paid attention to these cases. Because of it, there are strict standard in the world and in other side the internal combustion engine is very common.
In the internal combustion engine after cylinder, the gas inter to an encasement which is called exhaust manifold. In the other hand, exhaust manifold is in upstairs of turbine and waste-gate in turbocharged SI engines. To control fuel used and descries the amount of emissions, exhaust manifold pressure is very important. In the other hand, monitoring of exhaust manifold pressure can use for fault detection of leak in exhaust manifold. But installing sensor in this place isn’t suitable because of economic reasons. So in this project, an observer is designed for exhaust manifold pressure that the exhaust manifold pressure is estimated without any extra sensor.
There are a lot of approach and strategy for this case in literature. These approach can be divided to two type: static and dynamic approach. Static approach is used open loop estimate so it is not robust. The feedback is used in dynamic approach and it is more robust. So the dynamic approach is preferred to the static approach. The MVM approach is used for modeling of engine.
At the first, the engine air is divided two subsystem, intake manifold and exhaust manifold. These subsystem is used as two control volume. The pressure dynamic equations are written for these manifolds. A nonlinear state equation is represented for air engine with two states. Next, the throttle flow, the turbine flow and waste-gate flow are modeled and comparison with experimental date. An adaptive sliding mode observer is designed for cylinder flow. In the end, an observer is designed for pressure exhaust manifold based Lyapunov equation.
This research is developed a new approach for estimating volumetric efficiency. So instead lookup-table, this approach can be used. Additional, a simple observer is designed for pressure exhaust manifold that it has good accuracy. All results are validated by experimental test
- Turbochargers ; Spark Ignition Engines ; Volumetric Efficiency ; Exhaust Manifold ; Sliding Mode Observer