Three dimensional sensor laser noise reduction method
AssigneeGeneral Electric Company
InventorKevin George Harding
Life of this patent
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Abstract
A method for improving the accuracy of measurements made in non-contact gauging an object utilizing a detector to observe a laser line projected onto a surface of the object. A combination of detector lens f-number adjustments, surface scatter statistics, and laser coherence control are utilized to reduce speckle noise in the structured light gauge measurement system without the use of moving mechanical parts. This eliminates added mechanical motion errors and maximizes detectable laser light.
Claims10
A method for reducing laser speckle noise observed in an image by a detector in a non-contact gauge measurement system, comprising:
- projecting laser light having known speckle contrast onto a surface of an object;
- establishing, using said known speckle contrast and known measurement system accuracy limitations, a maximum observable speckle size;
- and
- selecting a detector lens having a lens f-number such that the size of the observed speckle points in said image is smaller than said maximum observable speckle size.
A method for reducing speckle noise present in an image of a laser line projected onto a surface of an object and observed through a lens by a detector, comprising:
- observing laser light scatter from the surface of the object;
- utilizing said observed laser light scatter to identify a minimum speckle noise size obtainable through lens f-number reduction;
- determining a lens f-number value corresponding to said identified minimum speckle noise size;
- and
- altering said detector lens by adjusting said lens f-number to said determined value.
A method for reducing speckle noise present in an image of a laser line projected onto a surface of an object and observed through a lens by a detector, comprising:
- identifying a minimum resolving power required to observe said projected laser line to within a predetermined range of measurement accuracy;
- and
- altering said detector lens by reducing a lens f-number to a minimum value having a resolution corresponding to said identified minimum resolving power.
Dependencies are inferred from the claim text.