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Convex Hull Sensor for Vibrating Plate Orienters

IP.com Disclosure Number: IPCOM000079530D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 60K

Publishing Venue

IBM

Related People

Will, PM: AUTHOR

Abstract

A basic orienter 10 of rectangular shape is shown in Fig. 1. A part dropped anywhere in the vibrator box 11 will slide down under vibration to point x and assume a position of (perhaps local) minimum potential energy. Parts which have distinct minima will assume a finite set of positions, symmetrical parts will not. The position is sensed either in the plane or perpendicular to the plane. Perpendicular methods are discussed in principle in optical character recognition and pattern recognition literature.

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Convex Hull Sensor for Vibrating Plate Orienters

A basic orienter 10 of rectangular shape is shown in Fig.
1. A part dropped anywhere in the vibrator box 11 will slide down under vibration to point x and assume a position of (perhaps local) minimum potential energy. Parts which have distinct minima will assume a finite set of positions, symmetrical parts will not. The position is sensed either in the plane or perpendicular to the plane. Perpendicular methods are discussed in principle in optical character recognition and pattern recognition literature.

Sensing in the plane is shown in Fig. 2 where the specific orientation is deducible from the shadow, and where the convex hull is sensed as shown in Fig. 3.

In Fig. 2 means is arranged for projecting a beam of light across the plane from a source, say l11, to a specific sensor (photocell) s11, etc. A single lamp with a fiber-optic bundle delivers light to the apertures "l"and a cylindrical lens focuses on individual cells. Values of s11 - s1n and s21-s2n possess a characteristic signature which allows orientation to be obtained. Values are analog, but most mechanical assemblies are opaque giving rise to binary signatures. This arrangement distinguishes between parts with significantly different dimensions in x - y coordinates.

Extraction of the approximate convex hull of an object is shown in Fig. 3, where it is assumed the part is positioned at point P by box 11. Lines PA and PB bound the part in an approximation to the convex hull at the point P. Sensors s1 to sn and lights l1 to ln are positioned to obtain an approximation to the other portion of the convex hull, provided the part is nonreflective.

A part is placed by box 11 in its minimum potential energy position by vibration. Then lamp l1 is put on. The light from l1 is arranged by suitable means to fall simultaneously on sensors s1 - sn.

These sensors are then scanned to determine which receive light and which do not. The procedure gives the ray from l3 nearest to point P outside the part. Repeating the procedure gives bounding rays from the other l's. This set of bounding rays is used to...