MATLAB: Simulink powertrain model approach

Question

For a school project I made an acceleration model for a fire engine. The vehicle part of the model all worked out well, but I am stuck modeling a powertrain. I dont have the powertrain blockset as it isnt available for students (?) and because my vehicle model is in simulink instead of simscape (And because I am not modeling a powertrain I just want to simulate the current one) I am not really in favor of using simscape.

My question is:

What is the best approach for simulating a powertrain (engine + transmission and shiftlogic) in simulink using a power vs. engine speed graph and kown gear ratios?

Answer 1

If you are not able to use Simscape but just Simulink, you can try to model your components by using look-up tables and stateflow.

• You can model the engine with a look-up table of engine speed versus output torque.
• You can model the transmission with shift logic by using a stateflow diagram.

If you do this, it basically boils down to an open loop approximation of a drivetrain written out manually. The aspects in which this simulation will be lacking is dynamics and transition periods. It is basically assuming that each sample of your model it is in steady state. So I would recommend using a sample time of something like 1 seconds.