Why do i keep getting keep getting an error saying"Derivative of state '1' in block 'CruiseCon​trolSystee​m/(m//s^2) naar (m//s)' at time 16.079617063361788 is not finite." in simulink?

I keep getting a error saying: "Derivative of state '1' in block 'CruiseControlSysteem/(m//s^2) naar (m//s)' at time 16.321775277082384 is not finite. The simulation will be stopped. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)" when i set my first constant(desired speed) above 82.

[Birdman]

Share your model.

[Jawad Aberkane]

Here you go!

Answer 1

[Birdman]

The reason for Derivative state for 1 errors arises from the fact that any signal in the model can not be properly calculated because of the adjusted step size at that moment. For instance, a signal rises up so quickly that no matter how much you increase the step size(try to calculate in smaller time intervals) you can not plot the signal well and actually this is what happens at your model because it provides a crucial warning, which needs to be fixed by the user.

Unable to reduce the step size without violating minimum step size of 5.19243207624119E-14 for 2 consecutive times at time 14.615396977316573. Continuing simulation with the step size restricted to 5.19243207624119E-14 and using an effective relative error tolerance of 1.2935087570751024E+65, which is greater than the specified relative error tolerance of 0.001. This usually may be caused by the high stiffness of the system. Please check the model 'CruiseControlSysteem' or increase Number of consecutive min steps

As it can be seen, the solver can not increase the step size to more than 5.19e-14, which means that if you want to solve the model with a fixed step, you will always fail. Therefore, you need to rebuild your model in a way that is controllable and solvable.

Hope this helps.