Databased Modeling of the Spatiotemporal Temperature Distribution in a Reachin Plant Growth Chamber

The spatiotemporal temperature distribution in the imperfectly mixed airspace around plants has a considerableeffect on the physiological plant processes. In a fully instrumented climate chamber, eight identification experiments werecarried out to model the spatiodynamic temperature response around plants to variations in the supply air temperature andthe sensible heat, produced by the lamps (directly related to the light intensity), as control inputs. From the experimental data,a minimally parameterized, linear, discretetime transfer function matrix (TFM) model was identified, capturing thedominant model behavior of the dynamic process. Based on statistical considerations, a firstorder TFM model came out asthe best model structure. The firstorder model provided a good compromise between goodness of fit (minimum Rt2i of 0.91)and parametric efficiency (standard error), characterized the airflow behavior very well, and formed an adequate basis formodelbased process control.