Hey guys,
consider a closed-loop with actuator saturation (see the image). What is the transfer function of this saturation block? And what is the closed-loop transfer function of the system?
I came up with this
Closed-loop transfer function:
H(s)= K(s)SAT(s)G(s) / 1+K(s)SAT(s)G(s)
where
SAT(u)=sign(u).min(|u|, u_lim) (u is bounded from -u_lim to u_lim)
but I don't think it's correct...
Any help would be greatly appreciated. Thanks A LOT
Have a great day
Liptak
Thank you for the answer. Yeah, but if , then saturation is non-linear, right? Saturation is non-linear, so we can't build a closed-loop transfer function, which is for linear time-invariant systems only (thanks captain, i should know that already ). How to describe it? Through non-linear differential equations or state space equations? Oh man, I'm screwed
Pratically, from the point of view of control theory, what is important is to extablish if a control system is stable with sufficient margin, if it has low sensitivity to disturbances and 'reasonable' transient time. All these parameters are of pratical importance if the system operates in linearity and that means that the actuator can be considered as a unity gain block...
Kind regards