Orientation of Apples Using Their Inertial Properties

摘要

Machine vision has the potential to improve quality and safety of fruit available for consumption. However, lack of an effective and inexpensive method for appropriately orienting fruit for imaging has hindered development of optical technologies for sorting fruit. For example, it is difficult to differentiate stem and calyx regions from problem areas in images. One solution would be to orient fruit so that the location of these regions is known. We demonstrated that apples can be oriented using their inertial properties. Apples were rolled down two test tracks each consisting of two parallel wooden rails using 100 Red Delicious and 100 Golden Delicious apples with three initial orientations of the stem/calyx axis: perpendicular, parallel, or at 45� to the rails. As the apples progressed down the tracks, they generally moved to an "oriented" position where the stem/calyx axis was perpendicular to the direction of travel and parallel to the plane of the rails. A camera was used to create movies of the orientation process, and software was written to automatically analyze the movies. Apples started in a perpendicular position were de facto oriented. Apples started at 45� almost instantly became oriented. For the parallel condition, orientation was delayed and was successful in only about half of trials. However, theoretical dynamics suggest that parallel loading would be a low probability event in a commercial setting. Alternatively, potential methods for circumventing this problem case are discussed.