Assessing the effect of machine automation on operator heart and breathing rate during mechanical harvesting of wild blueberries

Abstract

Wild blueberries (Vaccinium angustifolium Ait.) are among eastern Canada's most economically important crops. Despite this, the industry faces significant labor shortages required to harvest the over 69 000 ha of wild blueberry land each year. Automation of the wild blueberry is among the leading areas of wild blueberry research. The requirement to automate several different aspects of the harvester means that at present an operator is still required in the tractor. To determine the impacts that automation features have on an operator, and to assess the potential to replace skilled operators with unskilled ones, heart and respiration rates were monitored across various automatic, semiautomatic and manual harvesting conditions. Across both years of the study, the skilled operator experienced a 13.83% decrease in average heart rate under the fully automated condition versus the fully manual condition. Similarly, the new operator experienced a 19.03% decrease in average heart rate for the same scenario. While a conclusive determination cannot be made due to the significant interaction effect, it was likewise interesting to note that the skilled operator seemed to benefit more from the automated head adjustment while the new operator seemed to benefit more from the autosteer. Respiration rate data did not yield a conclusive trend, though the highest respiration rates were seen under the fully manual harvesting condition in all but the 2022 new operator data. In all, this study lays significant groundwork in the justification of automation for addressing the skilled labor shortage and for the eventual full automation of the wild blueberry harvester.