Planar manipulator matlab simulink error

I want implement feedback linearization for a planar manipulator 3 DOF. I define the desired position,velocity and acceleration for each joints for every 0.01s. So I set in solver options "Fixed-step with size of 0.01" to measure the corresponding error every 0.01. But I have this error.

This is the block diagram

If I put variable-step it works, but I have to measure the error every 0.01s and so I have to set fixed step at 0.01. Help me please. Thanks

Answer 1

[Suhan]

Please refer to the following discussion which addresses the issue you are facing: https://in.mathworks.com/matlabcentral/answers/339701-getting-the-error-message-derivative-of-state-x-in-block-xxx-at-time-xx-is-not-finite-the-simula

Basically, such issues occur when the model has instability. Below is information on three tools that may assist you in further improving the model stability if you are not already familiar with them:

1. Solver Profiler: The Solver Profiler can help you visualize your model dynamics and see where they may be unstable. Using the Solver Profile is described at this link: https://www.mathworks.com/help/simulink/ug/examine-solver-behavior-using-solver-profiler.html

2. Log the Simulink states, so you may view their values after running the simulation (perhaps stop the simulation before the error or use the above approach to remove the error): https://www.mathworks.com/help/simulink/examples/logging-states-in-structure-format.html

3. Use Stepping Options to pause the simulation and view signal values before the error occurs: https://www.mathworks.com/help/simulink/ug/simulation-stepper-interface.html