On-the-go yield and sugar sensing in grape harvester

Abstract

This paper summarises the results of a joint R+D project between university and industry. The study was developed at the Alt Penedès region, in Barcelona, during the 2006 and 2007 (on 3, 22, 69 fields respectively). The quality sensors set-up in year 2007, mounted on a New Holland SB55 grape harvester, were: two load cells, one refractometer, an ambient temperature prove and a GPS antenna, while in 2006 only the load cells and the GPS performed properly. The method used for this study is as follows: 1. Data recording from GPS and Logger (the latter is use for according and digitalising the sensor signal); 2. Wireless download of data to a PC; 3. Automatic data integration in a single file; 4. Lane automatic identification based on trajectory angles, machine forward speed determination, effective time calculation, masic flow, kg/m, and total amount harvested, kg/hopper, computation of characteristic soluble solid content and temperature during harvest; 5. Data broadcasting through GPRS to the winery; 6. Comparison of transmitted data with the invoice of the winery containers. After the season was finished, a data post processing was performed in order to a assess the causes of isolated incidences that were registered in 10 fields. Also a recalibration of the sensors for future seasons was performed. At current stage R 2 of 0.9547 is found between winery and in field yield data. Beside georeference data were gathered and compare to the remote photos in “Instituto Cartográfico de Cataluña”. Site-specific yield maps and speed maps have been computed while broad soluble solid information is not available due to slight dysfunctions of the grape juice pumping system towards to the refractometer.