Simulink - Generic Engine model not running properly on speed and torque vectors

Hello,

I've been having an issue with trying to make the generic engine model run according to measured data of a real engine. Essentially what happens is the engine speed starts at a certain speed and then exponentially decays towards zero. If I switch the engine model in the same system into a normalized 3rd order polynomial matched to peak power it starts working somewhat more realistically.

The same issue is present when I supply my vectors to the simulink example sdl_vehicle, so it seems simulink doesn't like my vectors, and I don't quite understand why.

The speed vector is (rad/s):

[130.9000 157.1000 183.3000 209.4000 235.6000 261.8000 288.0000 314.2000 340.3000 366.5000 392.7000 418.9000 445.1000]

And the torque curve vector is (Nm):

[75.0000 238.8310 280.5780 307.8750 299.1540 289.9390 280.7240 271.5090 262.3290 251.7160 238.8510 225.9870 215.5000]

Providing the image of the behavior below. Shaft speed1 is the engine model from my custom vehicle model with the speed and torque vectors. EngineRPM is the simulink sdl_vehicle example with my speed and torque vectors supplied.

If anyone knows what is wrong with the vectors I would really appreciate the help.

Kind regards,

Edvardas

[Saif Sayed]

Hi, were you able to get around this problem, I'm having the same issue. I even tried using the power vector but it isn't working?