International Business Machines Corporation

John E Griffith

David D Grossman

Peter M Will

Roger C Evans

Myron M Kutcher

A method and apparatus for calibrating a robot and using the results of this calibration to compensate for inaccuracies of the robot and also to diagnose robot deterioration. The method includes moving the robot to a set of nominal positions, commanded by the robot controller or measured by position encoders built into the robot, and determining the associated actual positions by measuring the robot position with an independent accurate measuring means or by aligning the robot end effector with an accurate calibration mask. The calibration results are stored and subsequently used to compensate for robot inaccuracy so that the robot moves to the actual desired positions.

Method and apparatus for calibrating a robot to compensate for

A quasi-liquid vise is provided for clamping irregularly shaped workpieces which comprises an open-topped vessel into which a workpiece may be inserted, a particulate fluidizable material located within and, substantially filling said vessel, pressure means connected to said vessel for introducing a gas or fluid therein to fluidize said particulate material, and means for applying a vacuum to said vessel and the particulate material to substantially solidify said particulate material when it is desired to clamp a workpiece therein. The solidifying effect of said vacuum applied to said particulate material may be enhanced by utilizing alternate layers of different sized particulate material wherein smaller particles fill voids and enhance the vacuum effect and hence the rigidity of the particulate material when it is desired to solidify same. Two additional approaches to improving the vacuum solidification effect include coating relatively dense particles with a somewhat resilient deformable material whereby better sealing action will be effected. Also, uniquely shaped particles may be utilized wherein a more rigid interlocking particle effect will be obtained upon application of the vacuum.

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Mahopac, NY, United States of America

John E Griffith