Lees, M. J. and Young, P. C. and Chotai, A. and Tych, W. (1995) A non-minimal state variable feedback approach to multivariable control of glasshouse climate. Transactions of the Institute of Measurement and Control, 17 (4). pp. 200-211.Full text not available from this repository.
The paper discusses the multivariable modelling and control of a glasshouse micro-climate. A linear reduced-order control model is obtained from a nonlinear simulation model using novel data-based model reduction and linearisation techniques. This control model is then used to design two multivariable non-minimal state variable feedback (SVF) control systems. The first utilises an LQoptimal Proportional-Integral-Plus (PIP) design method incorporating multi-objective optimisation of the weighting matrices, achieving partial dynamic decoupling; while the second uses an algebraic approach to combined pole-assignment and full dynamic decoupling. These controllers are evaluated, to ensure robustness, using the nonlinear simulation model, prior to implementation and evaluation on the real glasshouse during the 1993-94 winter growing season. Control results are excellent with very tight control to the desired setpoints in all three climate variables. For example, air temperature is controlled to within 0.5°C of the setpoint for 85% of the validation period, and is shown to be very robust to model uncertainty and extreme weather conditions.
|Journal or Publication Title:||Transactions of the Institute of Measurement and Control|
|Uncontrolled Keywords:||Non-minimal • state variable • feedback • multivariable control • glasshouse climate|
|Subjects:||G Geography. Anthropology. Recreation > GE Environmental Sciences|
|Departments:||Faculty of Science and Technology > Lancaster Environment Centre|
|Deposited On:||06 Feb 2009 13:12|
|Last Modified:||07 Jan 2015 13:37|
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