Re: FSM vs. Petri nets for component modelling...

>Do you mean that the following happens :
>1. oldcontrol runs + drives
>2. newcontrol listens passively on input for a few cycles
>3. oldcontrol output + newcontrol output is gradually mixed from 100 % old + 
>0% new to 0% old + 100 % new.
>4. oldcontrol switches out

Not exactly:

1. oldcontrol runs, listening for a begin switching signal;
2. newcontrol resumes and initializes, while oldcontrol still runs, maybe in 
degraded mode (e.g. servo-loops running and trajectory generator frozen);
3. when signal end-init received, oldcontrol output is disabled, newcontrol 
loop runs and sends its first output
4. oldcontrol executes its end code and suspends, while newcontrol runs  (and 
listening for events)

The output of the two control laws are never merged!

>What do you mean with " the task functions must have the same size'' ?

The task function is the error vector that the controller tries to minimize. 
It can be of different size, e.g. when switching from  2D motion to 3D motion. 
 This condition is for theoretic perfect transient control.

>Can you refer to one particular publication where these specific
>topics are explained in detail?

Try that one:

http://www.inrialpes.fr/bip/people/simon/rtcsa99.ps.gz


	Daniel