A Robust State Feedback Adaptive Controller with Improved Transient Tracking Error Bounds for Plants with Unknown Varying Control Gain

The design of robust model reference adaptive control (MRAC) schemes for plants in controllable form, comprising unknown varying but bounded coefficients and varying control gain has attracted a great deal of research. Many nonlinear systems may be described by the controllable form; for instance, second order plants (see (Hong & Yao, 2007), (Hsu et al., 2006), (Yao & Tomizuka, 1994), (Jiang & Hill, 1999)) and systems whose nonlinear behavior or part of it, is represented by some function approximation technique (cf. Nakanishi et al. (2005), (Chen et al., 2008), (Tong et al., 2000), (Huang & Kuo, 2001), (Yousef & Wahba, 2009), (Hsu et al., 2006), (Koo, 2001), (Labiod & Guerra, 2007)).