ISHS Acta Horticulturae 51: Symposium on Protected Cultivation of Flowers and Vegetables
A COMPUTER FOR CROP RESEARCH AND CLIMATE CONTROL IN GLASSHOUSES |
| Author: | J. van de Vooren |
| Abstract:
Plans to build a multifactorial glasshouse existed at the Naaldwijk Research Station for a long time. This plan has become true in its 75th anniversary (figure 1). The technical outfit of this glasshouse is described by Van de Vooren et al. (1975). Some aspects of the research experiments are described by Van de Vooren (1975). The control and registration of climatic factors in this multi-factorial glasshouse led to the choice of a processcomputer to perform this task (figure 2). A scheme is given in figure 3. To control a precess measurements of the factors to control has to be made. In each of the 24 compartments air temperature (5x), air humidity (3x), soil temperature (5x), water temperature of the heating system (2x) and ventilator position are registrated. A weather tower is used to measure air temperature, air humidity, wind velocity, wind direction and radiation. These data are stored on magnetic tape and on the disk. The data stored on the disk can be made visible on the graphical colour display and on the operator console (figure 4). The measurements of climatic factors in the compartments and on the weather tower and the settings, like temperature set points and limitations of water temperature of the heating system, deliver after some calculations the new position of mixing valves and ventilators. The old (measured) and new (calculated) positions of the controlling devices deliver the action the process-computer has to take (figure 3.4). An alarm on the operator console is made, when something is wrong with the measuring instruments or controlling devices for reasons of safeguarding the research experiments (figure 3, 4). Software is needed to make a computer work and to accomplish the described tasks. The software programmes are put at the disposal of the computer by a paper tape input device and are stored on the disk. Minor changes in the programmes can be made at the operator controle (figure 4). To give an impression of the user software the different parts - measuring, recordly, alarming, climate control - will be shortly described (figure 5). | |
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