Wireless control of passive systems subject to actuator constraints

TitleWireless control of passive systems subject to actuator constraints
Publication TypeConference Paper
Year of Publication2008
AuthorsKottenstette, N., and P. J. Antsaklis
Conference Name47th IEEE Conference on Decision and Control (CDC 2008)
Date Published12/2008
Conference LocationCancun, Mexico
ISBN Number978-1-4244-3123-6

Actuator constraints such as saturation can impose severe constraints on networked control systems. For instance delays in wireless control systems of unstable plants combined with actuator constraints may make it impossible to stabilize a system. In this paper the conditions are derived that show when actuator saturation, a common memoryless nonlinearity, in series with a passive system causes the loss of passivity. However, using a non-linear controller known as a inner-product recovery block, the overall passivity of the system is recovered. Furthermore, we note specific sector conditions in which strictly-input passivity and strictly-output passivity can be recovered. Finally, it is shown how the inner-product recovery block can be used to maintain an lm2-stable wireless control network.