H [infinity] controller synthesis for sampled-data systems and nonlinear systems

• Main Author: Yu, Qi.
• Other Authors: Er Meng Joo
• Format: Theses and Dissertations
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electronic systems
• Online Access: http://hdl.handle.net/10356/42742
• Institution: Nanyang Technological University

In this project, we first investigate the H∞ synthesis problem for a class of sampleddata control systems. We consider both Zero-Order Hold (ZOH) and Generalized Sample and Hold Functions (GSHF). Explicit formulae for such Hoc sampled-data controllers in case of linear time-invariant plants are given. Secondly, we examine the robustness of the Hoc controlled systems. It is shown that the sampled-data H∞ controller cannot achieve the same system's performance as the continuous-time controller does. However, by varying the sampling period, we show that sampled-data H∞ controller can reach a robustness level close to what a continuous-time H∞ controller can achieve when the sampling period is small enough. Furthermore, with the proposed GSHF-based controller, better robustness is obtained for the H∞ synthesis system in comparison with the ZOH-based controller.