Academic Report: Low-Order Controls for High-Order Dynamics, Where to Go?
Speaker：Dr. Si-Lu Chen
Time：2016.9.22 16:30-17:30
Location：Conference Room, 4th Floor, Hydraulic Old Building, Yuquan Campus
Abstract:
The physical motion systems may contain multiple resonant modes and be impeded nonlinear disturbances. But for ease of tuning and maintenance, the corresponding industrial motion controllers are generally in low-order, linear, and fixed structures forms, such as the PID and inertia feedforward controllers. Some of our recent proposed approaches to solve above conflict are discussed in this talk. Firstly, to cater for the current industrial practice of the trajectory planning up to the jerk, we have developed a model-based, third-order feedforward controller to concurrently handle both the rigid-body mode and the lump-sum of the flexible modes. Secondly, by incorporating this controller in both feedforward and feedback loops, and performing the follow-up data-based tuning of the fixed structure controller, we are able to achieve better tracking and disturbance rejection without compromising the performance of noise attenuation. Thirdly, to satisfy additional specifications such as energy saving and jerk-decoupling, solely tuning of the fixed structure controller is difficult. If time permits, I will talk about our proposed hybrid system-controller optimization approach, while we find that such a class of problems is not solvable by linear optimal control theory. Here, efficient optimization algorithm is developed to achieve parameter convergence as fast as the convex optimization counterparts.
Si-Lu Chen received his B. Eng and PhD degrees, both from the National University of Singapore (NUS), in 2005 and 2010 respectively. From 2010 to 2011, he was with Manufacturing Integration Technology Ltd, a Singapore-based semiconductor machine designer, as a senior engineer on motion control. Since 2011, he has been with Mechatronics group, Singapore Institute of Manufacturing Technology (SIMTech), Agency for Science Technology and Research (A*STAR). He is currently a scientist of SIMTech and an adjunct assistant professor of NUS. He is also co-PI of SIMTech-NUS Joint-Lab of Precision Motion Systems, leading two collaborative research projects, and PhD co-advisor for A*STAR Graduate School. His current research interests include integrated mechatronics design and optimization of high-speed motion control systems, and beyond-rigid-body control for compliant light-weight systems. He is currently serving as technical reviewers for IEEE/ASME Transactions of Mechatronics, IFAC Journal of Mechatronics, and ISA Transactions.