System and method for selecting a quality grade metric profile for assuring optimal control of symbol quality in a DPM process

A computer-implemented method for inspecting direct part marking (DPM) symbols, comprising:

• storing official metrics measured in a controlled environment for a “golden” sample;
• performing measurements of the DPM symbol of the “golden” sample;
• receiving an image of a DPM symbol on a part;
• performing measurements of the metrics of the “golden” sample in an uncontrolled environment;
• calculating statistical distributions of metrics from the uncontrolled environment;
• comparing the official metrics from the controlled environment and statistical distributions of individual metrics from the uncontrolled environment and determining a grade of each of a plurality of individual metrics of the imaged DPM symbol;
• identifying individual metrics that have lower grades in the uncontrolled environment than in the controlled environment;
• for each of the metrics, determining whether a determined grade of the corresponding metric of the imaged DPM symbol is below the acceptable grade from a profile of the corresponding metric;
• and
• in response to determining that a determined grade of the corresponding metric is below the acceptable grade of that corresponding metric, communicating a first signal to equipment for the equipment to perform a first physical action in processing the part, otherwise, communicating a second signal to the equipment for the equipment to perform a second physical action in processing the part.

A computer-implemented method of producing a metric quality grade profile for use during inspection of a direct part marking (DPM) symbol marked on parts, comprising:

• storing official metrics measured in a controlled environment for a “golden” sample;
• performing measurements of the DPM symbol of the “golden” sample;
• performing measurements of the metrics of the “golden” sample in an uncontrolled environment;
• calculating statistical distributions of metrics from the uncontrolled environment;
• comparing the official metrics from the controlled environment and statistical distributions of metrics from the uncontrolled environment;
• setting an acceptable grade for each of the individual metrics that have lower grades in the uncontrolled environment than in the controlled environment;
• configuring an imaging system to perform inspection of direct part marking symbols by storing, in a non-transitory memory on the imaging system, the acceptable grades for the individual metrics as a profile of the DPM symbol;
• during inspection of an imaged DPM symbol on a part, accessing the acceptable grades for the individual metrics stored in the non-transitory memory;
• determining a grade of each of a plurality of individual metrics of the imaged DPM symbol;
• determining whether any of the grades of the individual metrics of the imaged DPM symbol is below a stored acceptable grade from the respective individual metrics;
• and
• in response to determining that a determined grade of an individual metric is below an acceptable grade of that metric, communicating a first signal to equipment for the equipment to perform a first physical action in processing the part, otherwise, communicating a second signal to the equipment for the equipment to perform a second physical action in processing the part.

A system for inspecting direct part marking (DPM) symbols, comprising:

• an imaging device configured to capture images of DPM symbols on parts being processed by equipment;
• a non-transitory memory configured to store a profile inclusive of acceptable grades for each of a plurality of individual metrics of the DPM symbols;
• and
• a processing unit in communication with said imaging device and said non-transitory memory, and configured to:
• store, in the non-transitory memory, official metrics measured in a controlled environment for a “golden” sample;
• perform measurements of the DPM symbol of the “golden” sample;
• perform measurements of the individual metrics of the “golden” sample in an uncontrolled environment;
• calculate statistical distributions of the individual metrics from the uncontrolled environment;
• compare the official individual metrics from the controlled environment and statistical distributions of the individual metrics from the uncontrolled environment;
• identify the individual metrics that are lower in the uncontrolled environment;
• and
• enable the user to set an acceptable grade for each of the individual metrics that have lower grades in the uncontrolled environment than in the controlled environment;
• receive, from the imaging device, a captured image of a DPM symbol on a part;
• image process the captured image to determine a grade of each of the individual metrics of the imaged DPM symbol;
• determine whether any of the determined grades of the individual metrics of the imaged DPM symbol are below the acceptable grades of the respective individual metrics;
• and
• in response to determining that of the individual metrics of the imaged DPM symbol is below an acceptable grade, communicate a first signal to the equipment for the equipment to perform a first physical action in processing the part, otherwise, communicate a second signal to the equipment for the equipment to perform a second physical action in processing the part.

A computer-implemented method for inspecting direct part marking (DPM) symbols, comprising:

• storing official metrics measured in a controlled environment for a “golden” sample;
• performing measurements of the DPM symbol of the “golden” sample;
• performing measurements of the metrics of the “golden” sample in an uncontrolled environment;
• calculating statistical distributions of metrics from the uncontrolled environment;
• comparing the official metrics from the controlled environment and statistical distributions of individual metrics from the uncontrolled environment;
• identifying individual metrics that have lower grades in the uncontrolled environment than in the controlled environment;
• and
• enabling the user to set an acceptable grade for each of the individual metrics that are lower;
• receiving an image of a DPM symbol on a part;
• determining a grade of each of a plurality of individual metrics of the imaged DPM symbol;
• determining whether any of the grades of the individual metrics of the imaged DPM symbol is below an acceptable grade from a profile of the respective metrics;
• in response to determining that a determined grade of an individual metric is below an acceptable grade of that metric, communicating a first signal to equipment for the equipment to perform a first physical action in processing the part, otherwise, communicating a second signal to the equipment for the equipment to perform a second physical action in processing the part.