SEMINAR (ZOOM): Motion in the Ocean: Revolutionizing Marine Hydrokinetic Energy Harvesting Through the Optimal Periodic Motion Control of Ocean Kites

Abstract:

Tidal and ocean current resources in the United States have been estimated to contain 334 TWh/year and 163 TWh/year, respectively, of extractable hydrokinetic energy. This collectively comprises more than 10 percent of the annual U.S. energy consumption. The extraction of marine hydrokinetic energy in a 1 m/s flow speed through a fixed turbine requires approximately the same geometric sizing per unit of power as a wind turbine operating in a 10 m/s wind speed. Unfortunately, complications associated with undersea installation result in dramatically higher costs than comparably scaled wind energy counterparts. This talk will examine the use of ocean kites as a game-changing solution for extracting ocean current and tidal resources. Compared with a fixed turbine design, an ocean kite eliminates massive rotating underwater machinery and in fact reduces the size and mass per unit power of the underwater system by more than an order of magnitude. The key innovations in this technology, which also introduce significant control challenges, are twofold: First, a high-lift rigid kite is flown in high-speed cross-current orbits at favorable depths. Second, over the course of operation, the kite transitions between high-tension spool-out motion and low-tension spool-in motion, generating significant net positive energy at the location of the winch (either on a floating or seabed platform). This results in two periodic optimal motion control challenges, which must be performed concurrently and robustly, within a flow environment that is varying in both space and time. This seminar will illustrate how techniques from iterative learning control and continuous-time optimal control theory have been adapted to tackle these challenges. Furthermore, the seminar will highlight recent ongoing experimental efforts to validate dynamic models and control strategies for a prototype ocean kite design, which will ultimately culminate with tow testing of a 1/10-scale system. Finally, the seminar will provide future perspective on how concepts explored in the ocean kite control research and other related projects fit into a bold unifying research theme: control of renewably powered robotic systems.

Bio:

Chris Vermillion received his Ph.D. in Electrical Engineering from the University of Michigan in 2009 and received his undergraduate degrees in Aerospace and Mechanical Engineering from the University of Michigan in 2004. Immediately following his Ph.D. work, Dr. Vermillion worked on advanced automotive powertrain control, focusing on constrained optimal control approaches that simultaneously addressed the competing performance interests of fuel economy, emissions, drivability, and torque delivery. Subsequently he served as a Lead Engineer for Altaeros Energies and managed all of the dynamic modeling, control system design, software development, and embedded hardware development for Altaeros’ lighter-than-air wind energy system. Dr. Vermillion has participated in the full-scale flight testing of two of Altaeros’ designs. Dr. Vermillion is currently an Associate Professor at NC State, where his research focuses on the dynamic characterization, design optimization, and optimal control of airborne wind energy systems, marine hydrokinetic energy systems, and energy-efficient connected and autonomous vehicles. Dr. Vermillion was the recipient of the National Science Foundation’s CAREER Award in 2015, the UNC-Charlotte Maxheim Research Fellowship in 2016, and the UNC-Charlotte College of Engineering Excellence in Teaching Award in 2017.

Chris Vermillion Associate Professor, NC State University Mechanical and Aerospace Engineering

Zoom Information

Meeting ID: 999 4861 7641
Passcode: 932810