Optical-electronic monitoring apparatus
AssigneeErwin Sick GmbH Optik-Elektronik
InventorGerhard Herzer
Life of this patent
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Abstract
An optical electronic monitoring apparatus is used to detect undesired coil or lap formation at transport and drive rollers 13. For this purpose the beam 14 of a light barrier is arranged along the surface of the roller 13 parallel to its axis 23 in such a way that it is partially obscured by the cross-section of the roller. The subsequent evaluation circuit has a low pass filter 16, a differentiation stage 17 and a further low pass filter 18.
Claims20
Apparatus for monitoring undesired material buildup along the surface of a rotating object, the object having first and second ends through which an axis of rotation passes, the apparatus comprising:
- a radiant energy transmitter positioned at the first end of the object to direct a beam of radiant energy parallel to the object surface with a portion of the radiant energy beam being obscured by the object;
- a radiant energy receiver at the second end of the object positioned to receive at least a portion of the radiant energy beam;
- and
- an electrical evaluation circuit means, coupled to the radiant energy receiver, for providing an indication of material buildup along the object surface, the circuit means including in series a first low pass filter following the radiant energy receiver, a derivative stage for producing a first signal according to the change in radiant energy, received by the radiant energy receiver, with respect to time, and a second low pass filter for producing a second signal.
Apparatus for monitoring undesired material buildup along the surface of a rotating cylindrical roller, the roller having first and second ends through which the axis of rotation passes, the apparatus comprising:
- a radiant energy transmitter positioned opposite the first end of the roller to direct a beam of pulsed radiant energy parallel to the axis of rotation with a portion of the pulsed radiant energy beam being obscured by the roller;
- a radiant energy receiver opposite the second end of the object positioned to receive at least a portion of the pulsed radiant energy beam;
- means for synchronizing the pulsed radiant energy beam transmission according to the rotation of the rotating object;
- and
- an electrical evaluation circuit means, coupled to the radiant energy receiver, for providing an indication of material buildup along the object surface, the evaluation circuit means including in series a first low pass filter following the radiant energy receiver, a derivative stage for producing a first signal according to the change in radiant energy, received by the radiant energy receiver, with respect to time, and a second low pass filter for producing a second signal.
Apparatus for monitoring for undesired coil or lap formation at a roller, the roller having an axis, the monitoring apparatus comprising:
- a light barrier, including a light transmitter and a light receiver, the light transmitter producing a light beam directed along the roller surface parallel to the roller axis, the light beam cross-section being partly obscured by the cross-section of the roller;
- an evaluation circuit, connected to the light barrier, which transmits a signal if undesired coil or lap formation occurs;
- and
- the evaluation circuit including in series a first low pass filter following the radiant energy receiver, a derivative stage for producing a first signal according to the change in radiant energy, received by the radiant energy receiver, with respect to time, a second low pass filter for producing a second signal, and a threshold stage for transmitting a third signal when the second signal exceeds a pre-selectable threshold.
Dependencies are inferred from the claim text.