Evaluation of sensors for sensing characteristics and field of view for variable rate technology in grape vineyards in North Dakota
Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, USA, Natural Resource Program, North Dakota State University, Fargo, USA.
DOI: https://doi.org/10.37855/jah.2015.v17i02.19
Key words: Vineyards, sensors, variable rate technology (VRT), tree-sensing
Abstract: Sensors have been used to detect tree sizes for agrochemical and fertilizer applications in grape vineyards. Rugged and reliable sensors are required to measure the size and quality of tree canopy volume for variable rate fertilizer application. Real time sensing is important as size of the tree changes with time due to biological factors and management practices. This study evaluated ultrasonic sensor, optical sensor and a laser sensor for their sensing characteristics and field of view (FoV) in a range of conditions. The FoV was established by moving targets perpendicular to the centerline on both sides. The maximum sensig range of sensors varied from 6 to 8 m with ultrasonic sensor having the highest range. The beam widths for ultrasonic sensors were found to be wide (maximum 950 mm) whereas optical sensor has a narrow maximum beam width of 70 mm. The laser sensor has a sharp beam and did not work well in outdoor environment with plant materials. Statistical analysis was also done for sensors and found that P value is lower than 0.001 and R2 value closer to 1.0 which indicates significant better result in the vineyard for sensing characteristics.
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