Field Performance Evaluation Method for a Machine Vision Based Intra Row Hoeing Machine

Wageningen University and Research developed a machine vision based intra row hoeing machine in collaboration with Steketee, a manufacturer of agricultural machinery. Although the machine is used in agricultural practice for several years already there is still a lack of an experimental method to evaluate the field performance of such a device. Reliable, quantitative information about the performance of the machine in the field is therefore not known and the effect of variations in field conditions and machine settings on the performance were not previously researched. The relative number of crop plants damaged by the machine and the relative amount of soil around the crop plants not hoed were used as criteria to assess the field performance. The performance was measured both manually on the field and with the help of sensors by logging the actuation response of the hoeing elements. In the field trial four treatments were combined: 1) the relative number of lettuce plants, 2) the weed density on the field, 3) the driving speed during hoeing, and 4) the moment of hoeing. Each possible combination of treatments was repeated three times. It was concluded that the developed method was suitable to determine statistically significant differences in the hoeing results for the applied treatments. No difference in the machine performance was found for different numbers of missing crop plants in a plant row. The machine performance decreased in terms of the relative number of damaged crop plants in case of high weed density treatments and decreased in terms of the relative number of not hoed intra row spaces in case of high speed treatments.