Author：Yang, C. F.¹, J. Y. Chung², C. Lee¹

¹ Assistant Agricultural Engineer, Tainan District Agricultural Research and Extension Station, COA
² Associate Agricultural Engineer, Tainan District Agricultural Research and Extension Station, COA

Abstract：

    In order to improve the high temperature problem inside the greenhouse, and to search for a more reasonable method on operational settings of equipments, this research established a graphic interface of greenhouse environmental control system by using LabVIEW software. The graphic interface includes the display panel of the environmental condition, and control panel of the greenhouse. The system can display temperature, relative humidity, solar radiation and the operational states of equipments, and save the history of the measurements and control into a recording file. The system uses data acquisition hardware to grab measurement signals from transducers, and to send the control signals to drive external devices. The major control criteria of this research are the temperature inside the greenhouse, relative humidity and solar radiation of the outside. Also, we processed the control for ventilation, fogging and shading of greenhouse by adopting dead zone function. The result showed the temperature inside the greenhouse was lower than outside temperature in 1~2 ℃,and reduced the frequency in repeatedly ON-OFF operation of the equipment. The program for environmental control of the greenhouse was developed by using LabVIEW software . It has a better human-machine interaction characteristic, and much friendly to user.

Keywords: Data acquisition, Greenhouse environmental control, Dead zone