problem in simulink (FOPID controller)

Derivative of state '1' in block 'FOPIDC/Fractional PID controller1/Fractional derivative1/Transfer
Fcn1' at time 3.2188803386168852 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)
how can I solve this error

Answer 1

[Sam Chak]

It is not a problem with Simulink; rather, the design of your FOPID controller itself is insufficient to provide stability to the system.

To address this issue, design a stabilizing FOPID controller in accordance with the stability theorem.