On the morning of July 26th, Professor Lin Zongli from the University of Virginia in the United States was invited to our college for academic exchanges. In conference room 311 of No.1 Building in the South, a lecture entitled “Low Gain Feedback: For Constrained Control, Nonlinear Stabilization and Academic report of Control of Time Delay Systems” was given to the teachers and students. The report was hosted by Professor Wang Yanwu. More than 20 teachers and students from and outside our university attended the seminar.
Professor Lin Zongli is a professor at the University of Virginia. He received a B.S. from Xiamen University in 1983, a M.S. from Chinese Academy of Space Technology in 1989, and a Ph.D. in electrical and computer engineering from Washington State University in 1994. His research interests include nonlinear control, robust control, time-delay systems, and control applications. He served as Associate Editor for IEEE Transactions on Automatic Control (2001-2003), IEEE/ASME Transactions on Mechatronics (2006-2009) and IEEE Control Systems Magazine (2005-2012). And he is currently a member of the editorial board of Automatica, Systems & Control Letters, Science China Information. He was elected the board of directors of the IEEE Control Systems Chapter (2008-2010, 2019-2021), chairman of the IEEE Systems Control Systems Branch Nonlinear Systems and Control Technology Committee (2013-2015), and general chair or program chair of several conferences.
In this report, Professor Lin Zongli first used high-gain feedback control as the entry point, introduced the construction method of high-gain feedback controller under coordinate transformation, and pointed out the limitations of high-gain feedback control including actuator saturation, peaking, and constraints on the open-loop system with detailed simulation experiments. Then he introduced low-gain feedback control, presented the feature-based configuration method and three low-gain design algorithms based on algebraic Riccati equation with detailed design steps. After comparing the similarities and differences with high-gain feedback control, this report demonstrated the advantages of low-gain feedback control in dealing with issues such as saturation. Finally, he introduced the low-gain and high-gain feedback control methods which integrated the benefits of the two feedback controls in the case of actuator saturation. The stability of low-gain feedback control in nonlinear systems and a truncated predictive feedback control method for time-delay systems were analyzed.
The teachers and students enthusiastically communicated with each other, and the atmosphere was very lively. Professor Lin Zongli's visit has promoted the development in the academic research of small gain control and also gave great inspiration and help to the students. Finally, Professor Wang Yanwu expressed his gratitude to Professor Lin for his wonderful report.
