Transmission simulation solver crash

Hi,

I have a problem with my simulation. I tried to simply add 7 speed transmission to the Vehicle with Four speed transmission model. The model works with 8 or 6 speed transmission but for 7 speed it crashes and message appears "Error:An error occurred while running the simulation and the simulation was terminated:

Rotational velocity must be less than or equal to Maximum speed.

"

Answer 1

[Abhinaya Kennedy]

Hi Grzegorz,

The error "Rotational velocity must be less than or equal to Maximum speed" in your 7-speed transmission simulation suggests a component exceeds its maximum rotational speed. To resolve this:

1. Ensure the 7-speed ratios are correctly setand compare them with the working 6-speed and 8-speed setups to identify any discrepancies.
2. Review and adjust the maximum speed limits for all rotational components in the system to ensure they're realistic and sufficient.
3. Run the simulation in stages to pinpoint when and where the speed limit is exceeded. Monitor rotational velocities closely, especially during gear shifts.
4. If necessary, tweak simulation parameters such as damping, inertia, or the engine's power curve to prevent excessive speeds.

Additionally, you can also look into this example (https://www.mathworks.com/help/sdl/ug/transmission-testbed.html) of a testbed with interchangeable transmissions.

Here are links to documentations that could resolve the issue.

• 4-Speed Ravigneaux: https://www.mathworks.com/help/sdl/ref/7speedlepelletier.html
• 7-Speed Lepelletier: https://www.mathworks.com/help/sdl/ref/4speedravigneaux.html

Hope this helps!