The error message indicates an algebraic loop in your Simulink model. Algebraic loops occur when there is a circular dependency between blocks, such that the output of a block is used to compute its own input within the same time step. This can lead to issues like singularities, especially if the initial conditions are not well-defined or if the solver cannot find a consistent set of initial values.
You can try the following appraches to resolve this:
1. Setting appropriate initial conditions can help resolve this issue because Initial conditions provide the solver with a starting point, which can be crucial for models with algebraic loops. Here’s how you can set them:
- For blocks that have state variables (e.g., integrators, delay blocks), ensure that their initial conditions are set appropriately. You can specify these in the block parameters dialog.
- For algebraic loops, you might need to provide an initial guess for the algebraic state variables. This can sometimes be done by introducing an initial condition block or using a memory block to break the loop temporarily.
2. Try reducing the fixed step size or using a variable step solver with tighter error tolerances. This can help the solver find a consistent solution.
3. If possible, try to restructure the model to eliminate the algebraic loop. This might involve adding delays or reordering computations to break the direct feedthrough. Refer the following documentation link to read about various ways to do this in Simulink: https://www.mathworks.com/help/simulink/ug/remove-algebraic-loops.html
