modelling a resonator in simulink

1
votes

I have been trying to model the Fabry-Perot resonator in simulink. I am not sure if it is right to choose simulink for this task but I have been getting some results, at least. However, I have been also getting an error of algebraic loop when I use a different pair of coupling/reflection parameters. It says,

"Simulink cannot solve the algebraic loop containing 'jblock_multi_MR/Meander2b/Subsystem3/Real-Imag to Complex' at time 6.91999999999991 using the LineSearch-based algorithm due to one of the following reasons: the model is ill-defined i.e., the system equations do not have a solution; or the nonlinear equation solver failed to converge due to numerical issues. To rule out solver convergence as the cause of this error, either a) switch to TrustRegion-based algorithm using set_param('jblock_multi_MR','AlgebraicLoopSolver','TrustRegion') b) reducing the VariableStepDiscrete solver RelTol parameter so that the solver takes smaller time steps. If the error persists in spite of the above changes, then the model is likely ill-defined and requires modification."

Changing the solver does not help. As a note, I implemented the system in terms of electric fields and complex signals naturally.

thanks for any help.

1
simulink

1 Answers

2
votes

There is no magic solution for solving algebraic loop issues, as these issues tend to be very model-dependent. Here are a few pointers though:

See also this answer to a similar question on SO, with some suggestions for breaking the loop.