Torque Modeling and Control of a Variable Compression Engine
The SAAB variable compression engine is a new engine concept that
enables the fuel consumption to be radically cut by varying the
compression ratio. A challenge with this new engine concept is that
the compression ratio has a direct influence on the output torque,
which means that a change in compression ratio also leads to a change
in the torque. A torque change may be felt as a jerk in the movement
of the car, and this is an undesirable effect since the driver has no
control over the compression ratio.
The aim of this master's thesis work is to develop a torque control
strategy for the SAAB variable compression engine. Where the main
control objective is to make the output torque behave in a desirable
way despite the influence of compression ratio changes.
The controller is developed using a design method called Internal
Model Control, which is a straightforward way of both configuring a
controller and determining its parameters. The controller has been
implemented and evaluated in a real engine, and has proved to be able
to reduce the effect of compression ratio disturbance.
Senast uppdaterad: 2021-11-10