Title: Adaptive control scheme achieving smooth control input in the presence of input saturation

Authors: Natsuki Takagi, Masahiro Oya, Toshihiro Kobayashi, Qiang Wang

Addresses: Department of Mechanical Engineering, Miyakonojo National College of Technology, 473-1, Yoshio-cho, Miyakonojo-shi, Miyazaki, 885-8567, Japan. ' Department of Mechanical and Control Engineering, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka, 804-8550, Japan. ' Department of Mechanical and Control Engineering, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka, 804-8550, Japan. ' Department of Systems Design and Informatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka, 820-8502, Japan

Abstract: In this paper, the main attention is focused on transient property of control input signal, we propose a novel model reference adaptive control scheme for time continuous single-input single-output (SISO) linear systems with the input saturation. To improve the control performance, a novel estimator using an observer for the output tracking error signal is proposed. Using the estimator, it can be shown theoretically that the tracking error between the controlled object output and the reference model output can converge to zero when the initial value of the tracking error satisfies a condition. Moreover, in the case when the initial tracking errors are zero, it can be also shown that the control input signal becomes close to the exact model matching input signal rapidly by setting only one design parameter, and then, the input saturation does not occur.

Keywords: model reference adaptive control; MRAC; input saturation; control performance; control input signals; tracking errors.

DOI: 10.1504/IJAMECHS.2010.033595

International Journal of Advanced Mechatronic Systems, 2010 Vol.2 No.4, pp.225 - 235

Available online: 07 Jun 2010 *

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