Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

The overall goal of this study was to develop and evaluate an automated control system to adjust the movement of the shaking tines of a tractor drawn citrus mechanical harvesting machine. This system could potentially minimize tree injuries and help with ease of use and increase productivity of citrus mechanical harvesting operation. In citrus groves with significant variability in tree size, trees can be seriously damaged during harvesting by manually controlled mechanical harvesters because it is difficult for the operators to look back all the time and adjust the position of the tines. Two ultrasonic sensors were used to measure the distance of the tines from the canopy edge. A cable positioning sensor was used to report the location of tines. A program was written for this automated control system using LabVIEW and two systems were tested in a grove located in Florida. An RTK GPS was used to measure the location of the tines with respect to the tree canopy. The georeferenced data obtained from the GPS were overlaid on the aerial image of the test plots using GIS software. Using a Factorial design with mixed-effects, two systems were compared based on the mean values of the error term. There were significant differences between the treatments (the average distances between canopy boundary and manual run, canopy boundary and auto-run1, and canopy boundary and auto-run2). Based on the results obtained in this study, both automated control systems seem to be promising but need some improvements.