Date: Feb 14, 2013 11:49 AM
Author: Jason S
Subject: controlling simulink variable timestep size based on signals

(crossposted from StackOverflow: http://stackoverflow.com/questions/14877718/controlling-simulink-variable-timestep-size-based-on-signals)

I have a frequency ramp in Simulink (sin wt where w increases with time) and would like to use a variable-timestep solver. At the beginning of the simulation, the timesteps could be large; at the end, they have to be small.

I have tried tweaking the relative tolerance and it doesn't really seem to have a useful effect: the timesteps at the end are too long and the sinewaves have only 2-3 points per cycle.

Is there any way to somehow tie the timestep to the sinewave resolution, either directly or indirectly (e.g adding blocks in the simulation to somehow cause timesteps to decrease as frequency increases)?