Integrate the resulting model to see that it has 21 states (1 - Discrete Filter, 20 - Integer
Delay).
size(sys_default)
State-space model with 1 outputs, 1 inputs, and 21 states.
You can linearize this same model using the 'UseExactDelayModel' property as follows:
opt = linearizeOptions;
opt.UseExactDelayModel = 'on';
sys_exact = linearize(model,io,opt);
Interrogating the new resulting model shows that it has 1 state and the delays are
accounted for internally in the linearized model.
size(sys_exact)
State-space model with 1 outputs, 1 inputs, and 1 states.
Run a step response simulation of both linearized model to see that they are identical by
running the following commands.
step(sys_default,sys_exact);
h = legend('sys_default','sys_exact',...
'Location','SouthEast');
h.Interpreter = 'none';
2 Linearization