Method and apparatus for real time defect inspection of metal at elevated temperature
AssigneeTeledyne Industries, Inc.
InventorJohn W. Morris
Life of this patent
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Abstract
A system for detecting, in real time, the existence, depth, extent, and type of a defect in an above ambient temperature object which has been formed by working or other heat input. Such defect detection is performed by analyzing IR emissions from the product, and from a defect site in particular, in order to assess the characteristics of the detected defect. The defect observables are then compared with known defect training data in order to characterize the defect as to type, depth and extent.
Claims62
An apparatus for inspecting an object in real time to determine an existence of a defect in the object, said apparatus comprising:
- an IR detection device directed at a focal region on the object in order to detect IR radiation emitted from the focal region, said detection device outputting detection signals corresponding to the focal region which signals include temperature;
- a means for advancing the object to inspect another contiguous focal region on the object;
- computing means for maintaining a running average of detected temperatures and calculating a deviation threshold corresponding to said running average;
- and
- a memory containing pre-stored known defect profiles;
- said computing means determines the existence of the defect when a detected temperature exceeds said deviation threshold;
- said computing means determines a defect depth when the defect exists by analysis of a temperature gradient between detection signals in a particular focal region;
- said computing means determines a defect type by tracking the defect after the defect is detected and mapping the existence of the defect through contiguous focal regions to generate a defect signature pattern and comparing the signature with said pre-stored known defect profiles.
An apparatus for inspecting an object in real time to determine an existence of a defect in the object, said apparatus comprising:
- an IR detection device directed at a focal region on the object in order to detect IR radiation emitted from the focal region, said detection device outputting detection signals corresponding to the focal region which signals include temperature;
- a means for advancing the object to inspect another contiguous focal region on the object;
- transverse data processing means for processing detection signals from said focal region and generating transverse scan data corresponding to said focal region:
- longitudinal data processing means for compiling and correlating contiguous transverse scan data to generate an object profile;
- computing means having a memory for comparing said object profile with know defect profiles stored in said memory.
An apparatus for inspecting an object in real time to determine an existence of a defect in the object, said apparatus comprising:
- an IR detection device directed at a focal region on the object in order to detect IR radiation emitted from the focal region, said detection device outputting detection signals corresponding to the focal region which signals include temperature;
- a means for advancing the object to inspect another contiguous focal region on the object;
- data processing means for processing detection signals from contiguous focal regions into an object profile;
- computing means having a memory for comparing said object profile with defect profiles stored in said memory.
A method for inspecting an object in real time to determine an existence of a defect in the object, said method comprising the steps of:
- detecting IR radiation emitted by the object at a focal region;
- outputting detection signals corresponding to said focal region which detection signals include temperature;
- advancing said focal region relative to the object to the next contiguous focal region;
- maintaining a running average of detected temperatures and calculating a deviation threshold corresponding to said running average;
- indicating defect detection when a detected temperature exceeds said deviation threshold;
- determining a defect depth by assessing temperature gradient between detection signals for a particular focal region;
- identifying a defect by opening a tracking file when the defect is detected and mapping the defect through contiguous focal regions to generate a defect signature and comparing said defect signature with known defect profiles stored in memory.
A method for inspecting an object in real time to determine an existence of a defect in the object, said method comprising the steps of:
- detecting IR radiation emitted by the object at a focal region;
- outputting detection signals corresponding to said focal region which detection signals include temperature;
- generating transverse scan data by converting said detection signals into digital data;
- advancing said focal region relative to the object to a next contiguous focal region;
- compiling and correlating contiguous transverse scan data in order to generate an object signature;
- maintaining a running average of detected temperatures and calculating a deviation threshold corresponding to said running average;
- indicating defect detection when a detected temperature exceeds said deviation threshold;
- determining defect depth by analyzing temperature gradient between detection signals for a particular focal region;
- identifying the defect by comparing said signature with known defect profiles stored in memory.
Dependencies are inferred from the claim text.