Using Inverse control blocks for fast simulation

[Arminami]

I'm working on this Idea and got some results and I need some analysis and consultation on this :

This is the classic and simple way of Feedback control With a Plnet,Setpoint(w),controller(R):
I got the results in graph.

the RED LINE for the controlling Signal u
the BLUE LINE for set point w
the GREEN one for the out put y

now

if we try the bottom model which is the inverse of the above, hypotheticaly we have to get the same controlling signal u but it's not,
what does this mean ?anything about being fast?
how can we discuss the comparison ?

thanks.

 

[georgeverghese]

In your first sequence, the feedback signal (for comparison against the step change in the process variable) is shown to be the final controller output signal. In actual practice, it should be the process variable's reaction to the controller output ?

 

[Arminami]

I didn't get the point can you explain.

 

[georgeverghese]

In this first simulation, you've got the controller output signal acting as the process variable feedback against the step change in setpoint. That cannot be right.

How does the system process control variable change in relation to the change in controller output? This part of the control block is not here. Dont know how I can explain it in simpler language.