PhD Defense: "Control under Energy and Time Constraints"

Justin Pearson

January 18th (Thursday), 1:30pm
Harold Frank Hall (HFH), Room 4164

The performance of a control system is often limited by constraints on timing, bandwidth, and energy. This work explores the trade-offs between constraints on these resources, the control system performance, and the system to be controlled. We begin by considering a networked control system in which the sensor sends its measurements to the controller over a limited-bandwidth communications channel. We explore the observation that the absence of communication nevertheless conveys information — i.e., nothing communication-worthy occurred. This suggests that energy (or other resources consumed by communication) could be saved using the *timing* of messages to transmit information, rather than the normal practice of transmitting data in the messages themselves. We develop a framework to explore this idea and derive a condition for the existence of a stabilizing controller that captures the trade-off between bandwidth, resource consumption, and the unstable eigenvalues of the linear system to be controlled. Next, we use the framework to analyze a family of event-based controllers. We show that these controllers can stabilize a system while consuming resources at a rate that is within 2.5 times the theoretically-minimum rate. Finally, we explore how even non-networked systems can benefit from precise timing. We present a control architecture that allows a controller running on a non-real-time operating system to run with a high degree of determinacy, even in the presence of OS preemption.

About Justin Pearson:

photo of justin pearsonJustin Pearson is a graduate student in the department of Electrical and Computer Engineering at the University of California, Santa Barbara. He studied mechanical engineering at UCSB and Stanford University, emphasizing control systems.

For four years after graduation he worked on autonomous airplanes at AeroVironment. He designed and implemented control algorithms for the Global Observer aircraft: a giant high-altitude long-endurance prototype spyplane powered by liquid hydrogen. He deployed to Edwards Air Force Base for the aircraft's 15-month flight-test campaign. Afterward, he transferred to AeroVironment's Small Unmanned Aircraft Systems division, where he programmed guidance and navigation algorithms for hand-launched short-range military reconnaissance drones.

In 2012, Justin returned to UCSB to pursue a Ph.D. in electrical engineering and is advised by Professor João Hespanha in the Center for Control, Dynamical Systems and Computation. His research interests include information theory, optimization, and control and estimation over limited-bandwidth channels.

Hosted by: Professor João Hespanha