Design of robust sub-optimal nonlinear H∞ controllers with some applications

✍ Scribed by Mahdi Jalili; Behzad Moshiri; Parviz Jabedar Maralani

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 495 KB
• Volume: 12
• Category: Article
• ISSN: 1007-5704
• DOI: 10.1016/j.cnsns.2005.10.009

✦ Synopsis

The problem of nonlinear sub-optimal H 1 controller design with some applications is addressed in the paper. Nonlinear H 1 control has robust performance in response to external disturbances and parameter uncertainty as well as capability in dealing with nonlinear systems. In order to obtain the nonlinear H 1 control law, some partial differential inequalities so-called Hamilton-Jacobi-Isaacs (HJI) should be solved. There are some approximate solutions, which are generally based on the approximation of nonlinear parts of HJI inequalities. Using the Taylor series expansion, a sub-optimal solution for the HJI inequalities will be obtained. To assess the performance of the method, two applications are considered: the tracking problem of a two-degree-of-freedom rigid robot manipulator and speed control in a permanent magnet synchronous (PMS) motors. Simulation results show superior performance for higher order approximate controllers than that of lower order ones.