Vol. 86, No. 4
Abstract
Measurement of the Mechanical Actions by a Walking Tractor in the Case of an Operator Crushed
──Elucidating the Crushing Mechanism when a Loop-Shaped Handle Restrained an Operator──
[Keywords: walking tractor, loop-shaped handle, crushing force, axle torque, agricultural work safety]
Approximately 40 % of fatal accidents caused by walking tractors are crushing incidents. In this study, we supposed an operator was restrained between an object and a loop-shaped handle. The mechanical actions were measured as the walking tractor was driven, and the handle was in contact with the wall and ceiling at a height of 1.2 m. Results showed the maximum crushing forces were 4530±93 N, which can be fatal to the operator. We have formed an equation to estimate the horizontal distance from the tire axle and the point where the wheel ground reaction force is applied. From the measurements, the estimated distance was 89±1 mm. This shows the force was not active directly below the axle.
Development of a Traveling Unit for Steep Slopes and Its Adaptability to Harvesting and Transporting Operations
[Keywords: steep slope citrus orchard, robotization, electric powered carrier, travel stabilization, loading platform control]
Electric traveling units equipped with a loading platform control mechanism using electric cylinders, developed for stable traveling on steep slopes. The loading platform control reduced the differences in ground pressure balance in the contour direction and path deviation to the valley side. When traveling uphill, the center of gravity along the traveling direction provides hill climbing force, which is effective for traveling on incline. The second traveling unit, improved for practical use, could continuously operate for approximately 3 hours. Battery usage during harvesting and transporting in an approximately 11 a orchard was approximately 23 %, indicating that charging during work was unnecessary. Characteristics of harvesting and transporting on steep slopes are advantageous for electric traveling units.
Effects of Using GNSS Guidance for the Non-skilled Operator to Improve the Accuracy and Efficiency of the Tedding Operations
[Keywords: GNSS, Quasi-Zenith Satellite System, SLAS, GNSS guidance, operation accuracy, working efficiency, hay-tedding, non-skilled operator, skilled operator]
We investigated the tedding operation accuracy when a non-skilled operator worked on a skilled operator’s advice or with GNSS guidance. The non-skilled operator using a skilled operator’s advice could drive a tractor with the same accuracy of the skilled operator. When the non-skilled operator used GNSS guidance, the overlapping area was 26 % more compared to driving on a skilled operator’s advice, but all area was operated.
We measured the travel distance and work time of the nonskilled operator with and without GNSS guidance when the operator performed tedding in a 4.5 ha field. GNSS guidance reduced the driving distance by 33 % and the work time was 16 % lower. Thus, GNSS guidance could improve the work efficiency of a nonskilled operator.
Application Characteristics of Organic Fertilizer by Fluted Roll Type Fertilizer Applicator
[Keywords: organic fertilizer, organic farming, pellet fertilizer, fertilizer discharge accuracy, coefficient of variation, fluted roll]