Unexpected velocity and slip outputs from longitudinal vehicle model

Aim of the model is to convert an axle torque of a primitive 4 wheel drive vehicle into a vehicle velocity and monitor the slip in the tyres as a function of time. I have since found that this is very similar to the sdl_vehicle_4wd model in the Driveline Example library.

Even in the simplest simulation where I feed in a constant axle torque signal (4000Nm), I get a very messy vehicle velocity and slip output (on the order of 10^-32 in respective units) which is not what I was hoping for. The torque sensor does however reflect in the input signal correctly.

That said, when I comment out the torque sensor, it alters the simulation: it fails to converge to a solution in the first 8e-4s.

Would anyone be able to explain these results and how I could fix my model to get more realistic outputs.

[Kishan Makwana]

Apologies, forget to attach the file itself

Answer 1

[Steve Miller]

Your torque sensor needs to be connected in series with the torque source. You have it connected in parallel. See corrected model below.

--Steve