UCSC-CRL-04-10: A Control Approach to Bandwidth Management in Networked Control Systems

09/01/2004 09:00 AM
Computer Science
Bandwidth allocation techniques for control loops
closed over communication networks are based on static
strategies that ensure average control performance at the
expenses of permanently occupy the available bandwidth. In
this paper we present a dynamic approach to bandwidth
management in networked control systems that allow control
loops to consume bandwidth according to the dynamics of the
controlled process meanwhile attempting to optimize overall
control performance. By augmenting the original state-space
representation of each controlled process with a new state
variable that describes the network dynamics, 1) the allocation
of bandwidth to control loops can be done locally at run
time according to the state of each controlled process without
incurring in overload situations and 2) control laws can
be designed to account for the variations on the assigned
bandwidth preventing the unexpected control performance
degradation and even destabilization that would otherwise
occur. Experimental data show that the approach we present
permits to save bandwidth and even to improve control
performance with respect to the static strategy.