This article presents a controller design based on Lyapunov functions, which can be applied to a class of underactuated systems that cannot be feedback linearized in a specific set point.
Indeed due to the underactuated nature of the system, the model cannot be feedback linearized thus the most common and perhaps powerful tools of nonlinear control theory are ruled out and an alternative design strategy must be considered.
Thus one possible interpretation of our results is that the signal response is poorly coordinated across the population because the host cannot apply feedback to enforce tight coordination.
Networks constructed from steady-state gene expression data cannot have feedback loops [ 73- 75].
As a result, the patient cannot get feedback from his family doctor as to whether post-operative problems, such as urinary symptoms, are typical or constitute a complication in need of intervention.
So they cannot get crucial feedback — feedback that would both stop them from making similar mistakes in the future and make them realize that it is not a disaster — because they won't risk punishment or alienation for a blunder.
This important facet of feedback cannot be overlooked.
In such cases only position feedback cannot asymptotically stabilize the system.
A controller with temperature feedback cannot best achieve the thermal comfort.
