Browse Prior Art Database

Intermediate Sensor

IP.com Disclosure Number: IPCOM000106595D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 100K

Publishing Venue

IBM

Related People

Bloomberg, JA: AUTHOR [+4]

Abstract

The Intermediate Sensor was an idea that was implemented because of a problem that developed with the Megamation/SGRT Robot (Second Generation Robotic Test) Tool #91F1978, built by Megamation Inc.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Intermediate Sensor

      The Intermediate Sensor was an idea that was implemented
because of a problem that developed with the Megamation/SGRT Robot
(Second Generation Robotic Test) Tool #91F1978, built by Megamation
Inc.

      The problem was that the reciprocating arm used to probe nets
on a solid state circuit board was probing too deeply.  It was
probing too deeply because of slippage of the drive belt and
looseness of a lead screw nut during operation.  That condition
caused damage to the contact springs on the board, yet caused no
OPEN's during the continuity test that was in progress.  The encoder
was reading correctly.  However, after initial homing and and
alignment, the slippage caused the probe to propagate downward.  The
encoder is not capable of detecting that problem.  Therefore, the
Intermediate Sensor was devised to solve the problem, which was that
the encoder pulses did not assure that the physical location of the
tool was within the operational requirements.

      The Intermediate Sensor is used as a reference point for the
linear and rotating movements of a tool.  It provides a physical
verification of the location of a tool in a closed loop feedback
system (encoder/stepper motor).  The verification consists of a
computer program or other logic that will interpret the correlation
of signals from the Sensor and the encoder pulse count.  The
Intermediate Sensor should be located within the operating range of
the tool movement.

      The Intermediate Sensor should not be misconstrued with the
idea of a limit switch.  The Sensor functions within the normal
operating tolerances of a tool's movement.  That gives the program an
opportunity to verify that the tool is located at a position that
correlates with the encoder pulse count, and saves time in this
verification because the Sensor is conveniently located within the
operating zone (as opposed to re-homing, or moving outside the
operating zone to a limit switch).

      The design makes use of an actuator and a sensor (switch).  One
of these components is attached to a moving part in the mechanism,
the other component is in a fixed position.  The movement of the
mechanism will then cause the flag and the sensor to interact with
each other at a specific point within the operating rangeof movement.
The signal or lack of a signal from the Intermediate Sensor is then
interpreted by a computer program or some other logic.

      The use of the signal is based on how the system is setup by
the engineer and programmer.  It may be setup such that the computer
program will check for an active signal from the Intermediate Sensor
when the encoder is at a predetermi...