Validation test for the block IDEAS.Controls.OBC.CDL.Reals.Derivative.
The model integrates a time varying signal, and the differentiates
this integrated signal. Hence, the output der1.y
matches the non-integrated signal intWitRes.u, within
a small approximation tolerance.
The instance der1 uses a varying input for
T which controls the accuracy of the derivative
approximation. At the start of the simulation, T is
small and hence the output der1.y matches the signal
intWitRes.u well. As expected, the approximation error
increases with increasing der1.T.
The instance der2 uses a gain of 2, and it
initializes the output to 0. Hence, there is a fast
transient at the beginning, and afterwards the output matches
der1.y = der2.y / 2.