A. Gogoussis et M. Donath, RECIPROCAL VARIABLE FEEDBACK - INDUCED SENSING FOR NONLINEAR-SYSTEMS DESIGN AND CONTROL, Journal of dynamic systems, measurement, and control, 120(2), 1998, pp. 157-163
System performance can be significantly improved when both the design
of the plant and of the controller are considered concurrently. Contro
l theory can be applied to a broad variety of systems, including those
that are physical in nature and many, that are not. Despite the gener
ality of control theory, there are many situations in which opportunit
ies are missed for using less conservative control laws and simpler ov
erall implementations. This is due to the use of formulations that do
not explicitly reveal the existence of intrinsic information pertainin
g to the particular domain of application. Such is the case with many
physical systems. However, the various constraints associated with phy
sical reality (in the form of principles, laws, etc.) open up several
possibilities which can be exploited for system design and control. In
this paper, we propose the Reciprocal Variable Feedback principle as
a means for facilitating the control of plants with complicated nonlin
ear dynamics in the presence of parameter and/or structural uncertaint
y. The RVF principle exploits the effort-flow relationships associated
with power interactions in order to assist in the design and control
of physical processes. This is accomplished by using appropriate senso
rs instead of computation based on models (e.g., feedback linearizatio
n) and can be implemented within many physical domains. A motion contr
ol example is used to provide insight into the nature of the principle
. It is expected that in the future, additional principles will be ide
ntified and introduced for integrating design with the control of dyna
mical systems.