delay differential equations using DDE23

I am working on solution to system of equations of the form ydot=f(y,u) where u is control inputs. The control inputs appear in ydot equations. The control inputs are delayed due to compuational and sampling delays. Thus it is a DDE. Can i use DDE23 to solve these equations. The examples of DDE23 only talk about state delays. Control delays are not described.

Answer 1

[Torsten]

I guess that usually the controls at time t will be autonomous or a function of the state variables at earlier times.

Thus DDE23 can be applied.

Best wishes

Torsten.

Answer 2

[Pulkit Goyal]

If control input delays are a function of state themselves (e.g., in the case of a PID controller), then, the resulting differential equations become neutral delay differential equations. In this case, you can use ddensd in MATLAB to numerically integrate the set of dde.