How can I simulate a dynamical system backwards in time with Simulink 6.6(R2007a)?

I would like to be able to run my model backwards in time in Simulink.

This is not an uncommon problem in physics, i.e. if we could run a simulation of the universe backwards from now, we could see how we got here.

I am encountering a situation where it would be very handy to run a simulation backwards from some final state to a condition, and then restart the forward path, possibly with a perturbed state, to see how it affects the trajectory.

Answer 1

[MathWorks Support Team]

The functionality to simulate a model backwards in time is not possible in Simulink 6.6 (R2007a).

As a workaround, try to recast your system dynamics analytically so that the dynamics from final states to initial conditions are formulated as another dynamical system as if they are going from initial conditions to final states. However, it is clear that this is not a trivial task for the vast majority of the systems due to nonlinearities, delays and etc.