Plants need a specific

o the model parameters are auto-matically adjusted for changes in layout, maintenance, wear, etc,and this is a significant benefit for the controller implementationin practice.This paper utilizes the well-known extended Kalman filterfor adaptation of the model parameters over time (seasons). Itis applied to a special type of water-saving greenhouse, i.e. theWatergy greenhouse, which is described in the next section. Thisgreenhouse has been built in Almeria, Spain, to study possibilitiesfor extension of the growing season and increasing water use effi-ciency in horticulture by combining plant production with waterdesalination, water recycling and space cooling.To optimize the operation of the Watergy greenhouse an adap-tive model- based controller is developed to take into account thecomplicated structure of the control system and the multi-criteriagoals (production of both water and plants). The proposed controlsystem uses a physics-based model. For the sake of model simplicity0168-1699/$ – see front matter © 2009 Elsevier B.V. All rights reserved.doi:10.1016/j.compag.2009.01.012

However, model-based approaches like MPC assumethe availability of a state-space model that accurately describes the sys-tem dynamics governed by the involved physical phenomena. Within agreenhouse, the complex interactions among its individual components,controls, and environmental disturbances like outside weather condi-tions make it difficult to obtain a state-space model from first principles[21].

he library of candidate functions is reduced to the most affecting functions using SINDy-PI based on the unforced motion of the robot.

The condcond function in MATLAB is used to assess the condition number.

The precision of the solution for coefficients ξ\xi is not assured regardless of the method employed to solve an ill-conditioned matrix, i.e.,

A Morning ~ Walk

In mathematics, a rational function is any function that can be defined by a rational fraction, which is an algebraic fraction such that both the numerator and the denominator are polynomials. The coefficients of the polynomials need not be rational numbers; they may be taken in any field K.