Study On The Technology Of Field Information Fast Acquisition And Process Based On Virtual Instrument

Since 21st century, the development of computer technology and micro-electronics technology has penetrated the fields of measurement and instrument technology, and greatly stimulated them to further progresses. Virtual instrument (VI), as a new developing technology, is attracting more and more attentions in measurement and control field. On the other hand, precision agriculture (PA) is a very important aspect for agriculture development. PA would promote the change from extensive agriculture to knowledge and technology-based agriculture. According to the condition of China, the acquisition of field information is the premise and difficulty for PA practice. This paper mainly studied the technology of field information acquisition and process based on techniques of GPS, sensors, database and virtual instrument. The studies have expanded current field information measurement methods and strengthen the application of virtual instrument. The main contents of this paper include:(1) Virtual instrument is beyond c ompared w ith traditional instrument, which includes lower cost of exploitation and maintenance, shorter period of technology update, flexibility and so on. Therefore, aimed at drawbacks in field information acquisition, a new project of VI-based system for real-time measuring field information was put forward.(2) The method and principle for fast measurement field information were studied. A VI measurement system for measuring field information was developed using sensor technique, signal conditioning technique, database technique etc. This system composed of several sensors, a DAQ card and computer system, in addition, this VI application was designed using Graphical language LabVIEW. It could measure multi-variable at the same time, which avoiding using many different instruments to measure whole file information at present.(3) Based on the analysis of the principle of GPS location and output-sentence format, the software interface were designed for OEM GPS receiver and computer to realize GPS data acquisition by computer. The methods of processing GPS data was given, and the gauss transform of GPS data was achieved by application program.(4) A pH electrode was used to acquire soil pH, and the methods of electric-potential analysis and two-point correction were selected to improve the measurement precision. A thermocouple was used to acquire soil temperature,...