Portable data acquisition system for measuring energy requirements of soil - engaging implements

Lackas. G.M., Grisso, R.D., Yasin, M. and Bashford, L.L., 1991. Portable data acquisition system tbr measuring energy requirements of soil-engaging implements. Comput. Electron. Agric., 5: 285-296. A portable data acquisition system, using a laptop computer, was developed to monitor performancc of soil-engaging implements during field operation. The vertical and horizontal forces exerto:l by the implement, ground speed and other parameters were measured. A spreadsheet program was used to aid data analysis and storage. I N T R O D U C T I O N Instrumentation systems to determine energy requirements and efficiencies of tractor-implement systems have been developed by machinery manufacturers, universities and governmental agencies. Complete tractor data acquisition systems are generally expensive, and complex. Many are dedicated to one tractor and not easily adaptable to other machines. Most systems for measuring tractor performance (Grevis-James and Bloome, 1982; Tompkins and Wilhelm, 1982; Shropshire et al., 1983; Clark and Adsit, 1985; Alimardani et al., 1987; Esch, 1987; Graham et al., 1987; Selfet al., 1987; Thomson and Shinners, 1987; Griffith et al., 1988) were designed to measure ground speed, drawbar pull, and drive wheel speed. From these measurements, drawbar power and wheel slip could be calculated. Ground speed has been measured from rotational velocity of a non-drive wheel (Grevis-James and Bloome, 1982), a free-floating fifth-wheel (Tompkins and Wilhelm, 1982), radar and sonic units (Thomson and Shinners, 1987; Griffith et al., 1988). The axle or drive-wheel speeds were measured Published as Paper No. 9026, Journal Series, Agricultural Research Division, University of Nebraska, Lincoln, NE, U.S.A. 0168-1699/91/$03.50 © 1 9 9 1 Elsevier Science Publishers B.V. 286 G.M. LACKAS ET AL. using magnetic sensors (Tompkins and Wilhelm, 1982; Self et al., 1987 ), direct-current tachometers (Clark and Adsit, 1985 ), rotary encoders (Thomson and Shinners, 1987) or indirect measurements from the engine speed (Griffith et al., 1988 ). The drawbar pull has been measured from strain gages mounted in tractor drawbars (Grevis-James and Bloome, 1982 ), strain gaged three-point links and three-point hitch dynamometers (Tompkins and Wilhelm, 1982; Johnson and Voorhees, 1979 ). Other devices used with these systems monitored: fuel consumption (Tompkins and Wilhelm, 1982; Shropshire et al., 1983; Clark and Adsit, 1985; Alimardani et al., 1987; Esch, 1987), axle torques (Tompkins and Wilhelm, 1982; Shropshire et al., 1983; Self et al., 1987 ), and dynamic wheel load (Self et al., 1987). One data acquisition package had a radio telemetry system (Freeland et al., 1988) that protected the microprocessor from a harsh environment. Most systems used for monitoring tractor performance could be easily adapted for measuring implement energy requirements. However, a universal system with sufficient portability and ease of exchange between both tractors and implements has not been developed.