© 2005 ISA—The Instrumentation, Systems, and Automation Society.
Multi-model direct adaptive decoupling control with application to the wind tunnel systemBy Xin Wang, Shaoyuan Li, Wenjian Cai, Heng Yue, Xiaojie Zhou, Tianyou Chai
Institute of Automation, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China; School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore; Research Center of Automation Northeastern University, Shenyang, 110004, People’s Republic of China
Abstract
In this paper, a new multi-model direct adaptive decoupling controller is presented for multivariable processes, which includes multiple fixed optimal controllers, one free-running adaptive controller, and one re-initialized adaptive controller. The fixed controllers provide initial control to the process if its model lies in the corresponding region. For each controller selected, the re-initialized adaptive controller uses the values of this particular controller to improve the adaptation speed. This controller may replace the fixed controller at a later stage according to the switching criterion which is to select the best one among all controllers. A free-running adaptive controller is also added to guarantee the overall system stability. Different from the multiple models adaptive control structure proposed in Narendra, Balakrishnan, and Ciliz [Adaptation and learning using multiple models, switching, and tuning. IEEE Control Syst. Mag. 15, 37–51 (1995)], the method not only is applicable to the multi-input multi-output processes but also identifies the decoupling controller parameters directly, which reduces both the computational burden and the chances of a singular matrix during the process of determining controller parameters. Several examples for a wind tunnel process are given to demonstrate the effectiveness and practicality of the proposed method.
© 2005 ISA—The Instrumentation, Systems, and Automation Society.
Design and analysis of controllers for a double inverted pendulumBy Henrik Niemann, Jesper Kildegaard Poulsen
Ørsted-DTU, Automation, Technical University of Denmark, Building 326, DK-2800 Lyngby, Denmark; Intentia Danmark A/S, Borupvang 5 D-E, DK-2750 Ballerup, Denmark
Abstract
A physical control problem is studied with the
H and the
u methodology. The issues of modeling, uncertainty modeling, performance specification, controller design, and laboratory implementation are discussed. The laboratory experiment is a double inverted pendulum placed on a cart. The limitations in the system with respect to performance are the limitation in the control signal and the limitation of the movement of the cart. It is shown how these performance limitations will effect the design of
H and
u controllers for the system.
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