Browse Prior Art Database

Variable Sensitivity Tactile Sensing Wand

IP.com Disclosure Number: IPCOM000084131D
Original Publication Date: 1975-Sep-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 39K

Publishing Venue

IBM

Related People

Will, PM: AUTHOR

Abstract

Mechanical manipulators employ sensing wands or antennae to detect the position of the workpiece relative to the manipulator. The manipulator is animated in three orthogonally disposed directions and rotatable about three axes. By introducing into a computer the attitude and displacement of the manipulator to which the sensing wand is attached when the wand contacts the workpiece, information can be derived as to the shape and orientation of the workpiece to guide the subsequent movement of the manipulator to operate upon the workpiece directly, or through the use of assembly tools.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Variable Sensitivity Tactile Sensing Wand

Mechanical manipulators employ sensing wands or antennae to detect the position of the workpiece relative to the manipulator. The manipulator is animated in three orthogonally disposed directions and rotatable about three axes. By introducing into a computer the attitude and displacement of the manipulator to which the sensing wand is attached when the wand contacts the workpiece, information can be derived as to the shape and orientation of the workpiece to guide the subsequent movement of the manipulator to operate upon the workpiece directly, or through the use of assembly tools.

In prior tactile sensing devices, a flexible wand was mounted as a cantilever beam with annular contacts surrounding the wand, such that flexure of the wand made electrical contact between it and the annular contacts to provide the sensing signal. These devices had a fixed sensitivity in that closure of the contacts required a constant deflection at the end of the wand.

The apparatus to be described provides a variable sensitivity by adjusting the relativity of the annular contacts to the wand. Beam theory describes the elastic curve of a cantilever beam as: y = Wx/2/(3l-x) over 6EI. where y is the vertical deflection at the distance x from the beam mount, l is the beam length, E is the modulus of elasticity, I is the moment of inertia of the beam cross section, and W is the deflection load.

Since E and I for a wand of fixed cross section are fixed, these parameters are constants in the above relationship. So, also, since the annular contact structure responds to a fixed deflection, the deflection y for contact closure is a constant. Therefore, the above equation reduces to: W = K over x/2/(3l-x).

From this, it can be intuitively appreciated that the force at the end of the wand required to effect contact closure can be adjusted by varying l and/or x, so long as x and l are not so varied as to produce the same W.

While both x and l can be varied, the apparatus to be described varies,...