Model Predictive Control of a drivetrain with a Starter/Generator
The aim of this Master Thesis is to control a vehicle with a
Starter/Generator included in the drivetrain with the help of an
on-line control method called Model Predictive Control (MPC). The
controller is to be used as a cruise controller and attempts are made
to lower the fuel consumption with the help of MPC. The control
signals are the throttle angle and a current associated with the torque
that can be obtained from the Starter/Generator. The reference signal
is velocity.
The control work is divided into two parts, linear and nonlinear MPC.
For the linear MPC the vehicle model is firstly linearized and the
obtained linear model is used in the making of the linear controllers.
The controllers are derived for different criteria and around
different working points, and tested on the nonlinear model. The
following of the reference velocity is good, but it is not possible
to directly influence the fuel consumption. To be able to cover a
larger reference velocity range the linear controllers are combined in
two different switching strategies, were a supervisor decides what
controller to use in a particular instant.
To be able to more directly influence the fuel consumption, nonlinear
MPC is tried. A complete numerical solution
would require substantial calculation time so a approximative method
is used. The approximative method is tested for two different
criteria, were one directly includes the fuel consumption. The approximative method does not give as good a result as
the linear controllers with regards to the reference following. With regards to the fuel consumption the result is hard to interpret
since the control values assume unrealistic values.
Zandra Jansson
2001
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Last updated: 2021-11-10
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