Development of a Test Bench for Vibration Measurements of Hand-Held Harvesters for Olives

Olive harvesting is the most expensive activity among cultural operations, so its mechanization is essential to reduce production costs. For this reason, the use of hand-held vibrating harvesters is quite widespread where full mechanization is not possible. However, these machines expose operators to high vibration risks for the hand-arm system. The assessment of the effective risk requires direct measurement under real working conditions or the definition of standardized procedures able to provide reliable acceleration values. Although this need has long been known, a unified regulation for this purpose does not yet exist. To this end a test bench was designed and built at the Section of Mechanics and Mechanization of the Department of Agriculture, Food and Environment, to simulate in a reproducible way the load resistance the branches offer during harvesting. The test bench has an aluminum frame with a working area of about 1.5 × 1.5 m and allows testing all the main models of combo, beater or flap-type hand-held harvesters available on the market. The working area consists of vertical and horizontal nylon wires with adjustable spacing and tension to 2D-simulate the crown of the tree and to provide the load during the tests. The wires are stretched by means of springs and simultaneously about equally preloaded by moving a vertical and a horizontal bar of the frame. Fixing the preload and the distance between the wires, the load conditions for the machine under test are almost constant and measurements should be reproducible over time.