Problem with derivative du/dt in Simulink

Hello, i have a problem with using the derivative of the speed of a machine in Simulink. The following message pops up: Unable to reduce the step size without violating a minimum step size of 2.2250738585072014E-308 at time 1.3034180890316852E-308. The simulation parameters of my model are on the attached image. Any ideas? Thx

Answer 1

[prabhat kumar sharma]

Hello Alexis,

This error can occur when the solver is unable to solve the equations within the step-size provided. Increasing the number of consecutive minimum steps can help the solver manage the step size more effectively.

You can follow the below steps:

1. Open the Solver Configuration: Go to the Solver section in the Configuration Parameters dialog box.
2. Expand Additional Options: Click on the ‘Additional options’ section to expand it.
3. Increase Consecutive Min Steps: Look for the dialog box titled ‘Number of consecutive min steps:’ and increase the value. A good starting point might be to set it to 10 or higher, depending on your model’s requirements.

Additionally, relaxing the tolerances can also help. You can do this by:

1. Adjusting Tolerances: In the Solver section, find the fields for Relative tolerance and Absolute tolerance. Increase these values slightly to give the solver more flexibility. For example, you might set the Relative tolerance to 1e-3 and the Absolute tolerance to 1e-6.

I hope it helps!

[ALEXIS]

I thought this day would never come! 10 years have passed since I asked this question, 10 years I've been waiting for the answer.

Too bad I don't use Matlab anymore. But I appreciate the effort.

[Hakime Hanife Gören]

Hi Alexis the problem 10 years ago. I have the same problem and changing solver settings etc. do not work. When I get the derivative of speed, to get acceleration it gives the exactly same error. I also asked chat gbt it gave the same solution advice, it still does not give any solution at all.