Method for predicting root cause of defects in assembly units

The method of claim, further comprising:

• identifying a first inspection stage associated with detection of the defect according to the defect log;
• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• calculating a count of intermediate assembly stages between the first assembly stage, associated with the defect, and the first inspection stage;
• and
• in response to the count of intermediate assembly stages exceeding a threshold count, recommending installation of the first inspection stage immediately succeeding the first assembly stage.

The method of claim, further comprising:

• calculating a count of assembly components, in a first set of assembly components required for repair of the defect associated with the first assembly unit;
• identifying a defect assembly stage associated with onset of the defect based on the set of features;
• calculating a downstream propagation stage count representing propagation of the defect to downstream assembly stages based on the defect assembly stage;
• calculating a composite defect value based on the count of assembly components and the downstream propagation stage count;
• and
• calculating the threshold count of intermediate assembly stages proportional to the composite defect value.

The method of claim, wherein defining the bounded region of the assembly graph comprises:

• identifying a first edge representing introduction of a particular assembly component corresponding to the first set of visual features;
• identifying a second edge corresponding to a latest assembly process configured to influence the particular assembly component corresponding to the first set of visual features;
• and
• defining the bounded region of the assembly graph comprising the first subset of nodes and the first subset of edges between the first graph element and the second graph element.

The method of claim, further comprising:

• accessing an assembly specification specifying the set of assembly processes for the set of assembly units;
• accessing a log of manufacturing inputs representing a corpus of non-visual and visual features captured during manufacturing of the set of assembly units;
• deriving a set of assembly components and subassemblies introduced during manufacturing of the set of assembly units;
• defining the set of nodes, each node in the set of nodes representing an assembly component in the set of assembly components;
• defining the set of edges, each edge in the set of edges representing an assembly action in the set of assembly processes and connecting nodes corresponding to assembly components joined during the assembly action;
• and
• generating the assembly graph comprising the set of nodes and the set of edges.

The method of claim, further comprising:

• accessing a set of historical defect logs for the set of assembly units, the set of historical defect logs identifying defective assembly units in the set of assembly units;
• and
• for each defect specified in the set of historical defect logs:
• for each feature in the corpus of non-visual and visual features:
• identifying an anomaly value for the feature based on a distribution of feature values for assembly units, in the set of assembly units, exhibiting the defect;
• identifying a target subset of features, in the corpus of non-visual and visual features, exhibiting anomaly values exceeding a threshold anomaly value;
• for each feature in the target subset of features:
• generating a correlation between the feature and the defect based on the anomaly value;
• identifying a graph feature, in the assembly graph, associated with the feature;
• and
• associating the correlation and the defect with the graph feature;
• identifying a root cause of the defect based on the target subset of features and corresponding correlations between features, in the target subset of features, and the defect;
• and
• associating the root cause with graph features in the assembly graph corresponding to features in the subset of target features.

The method of claim:

• wherein generating the correlation, in a set of correlations, between the feature and the defect comprises, for each feature in the set of features:
• generating a first-order correlation, in a set of first-order correlations, between the feature and the defect;
• and
• generating a second-order correlation, in a set of second-order correlations, between the feature, a second feature in the set of features, and the defect;
• wherein assembling the set of correlations into the correlation matrix comprises:
• assembling the set of first-order correlations and the set of second-order correlations into the correlation matrix;
• and
• wherein isolating the first subset of features comprises:
• detecting a target second-order correlation, between a first visual feature and a second nonvisual feature and the defect, exceeding the threshold correlation;
• and
• isolating the first subset of features comprising the first visual feature and the second nonvisual feature.

The method of claim, wherein isolating the second set of nonvisual features associated with the defect according to the defect log comprises:

• accessing an assembly type of the first assembly unit based on the defect log;
• accessing a feature map linking non-visual features to locations within assembly units of the assembly type;
• accessing an inspection image depicting the first assembly unit and recorded by an optical inspection station during manufacturing of the first assembly unit;
• projecting the location of the defect onto the inspection image;
• and
• aggregating the second set of non-visual features associated with locations proximal the location of the defect.

The method of claim:

• wherein isolating the first set of visual features spatially proximal the location of the defect on the first assembly unit comprises isolating a first set of assembly components spatially proximal the location of the defect on the first assembly unit;
• wherein isolating the second set of nonvisual features associated with the defect according to the defect log comprises isolating a first set of assembly processes associated with the first set of assembly components;
• wherein isolating the first set of features defined in the bounded region of the assembly graph comprises:
• isolating a first subset of nodes, in the assembly graph, representing the first set of assembly components;
• and
• isolating a first subset of edges, in the assembly graph, representing the first set of assembly processes;
• wherein generating the correlation, in the set of correlations, between the feature and the defect comprises:
• extracting a first set of correlations between the first subset of nodes and the defect based on the assembly graph;
• and
• extracting a second set of correlations between the first subset of edges and the defect based on the assembly graph;
• and
• wherein assembling the set of correlations into the correlation matrix comprises:
• assembling the first set of correlations and the second set of correlations into the correlation matrix.

The method of claim, further comprising:

• accessing a corpus of inspection images, captured by optical sensors installed at a set of inspection stations, of the set of assembly units;
• deriving a set of assembly components associated with manufacturing of the set of assembly units based on the corpus of inspection images;
• based on timestamps of inspection images in the corpus of inspection images, temporally ordering the corpus of inspection images to derive an assembly sequence for manufacturing of assembly units in the set of assembly units;
• defining the set of assembly processes for manufacturing of the set of assembly units based on the assembly sequence and visual differences between pairs of inspection images in the corpus of inspection images;
• defining the first set of nodes, each node in the first set of nodes identifying an assembly component in the set of assembly components;
• defining the first set of edges, each edge in the first set of edges identifying an assembly process, in the set of assembly processes, and linking assembly components in the set of assembly components;
• generating the assembly graph comprising the first set of nodes and the first set of edges;
• accessing a set of defect logs associated with the set of assembly units;
• and
• for each defect identified in the set of defect logs:
• isolating a subset of features associated with the defect;
• and
• associating the defect with a node in the assembly graph based on the subset of features.

The method of claim, further comprising:

• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• identifying a first inspection stage succeeding the first assembly stage;
• accessing a set of sensor data captured by sensors deployed at the first inspection stage;
• deriving a set of tests administered at the first inspection stage based on the set of sensor data;
• and
• in response to detecting absence of a test configured to detect defects similar to the defect in the set of tests, recommending addition of the test configured to detect defects similar to the defect at the first inspection stage.

The method of claim, further comprising:

• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• identifying a first inspection stage succeeding the first assembly stage;
• accessing a set of sensor data captured by sensors deployed at the first inspection stage;
• deriving a set of tests administered at the first inspection stage based on the set of sensor data;
• and
• in response to detecting presence of a test configured to detect defects similar to the defect in the set of tests:
• accessing a tolerance range of the test;
• predicting a test result for the first assembly unit on the test based on the defect log;
• and
• decreasing the tolerance range of the test to include the test result.

The method of claim, further comprising:

• identifying a first inspection stage associated with detection of the defect according to the defect log;
• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• calculating a count of assembly components, in a first set of assembly components required for repair of the defect associated with the first assembly unit;
• identifying a defect assembly stage associated with onset of the defect based on the set of features;
• calculating a downstream propagation stage count representing propagation of the defect to downstream assembly stages based on the defect assembly stage;
• calculating a composite defect value based on the count of assembly components and the downstream propagation stage count;
• calculating the threshold count of intermediate assembly stages proportional to the composite defect value;
• calculating a count of intermediate assembly stages between the first assembly stage, associated with the defect, and the first inspection stage;
• and
• in response to the count of intermediate assembly stages falling below the threshold count of intermediate assembly stages, recommending installation of the first inspection stage immediately succeeding a second assembly stage succeeding the first assembly stage and exceeding the threshold count of intermediate assembly stages from the first assembly stage.

The method of claim, further comprising:

• accessing a corpus of defect logs associated with the set of assembly units;
• identifying a first inspection stage associated with detection of the defect according to the set of defect logs;
• calculating a count of assembly units, in the set of assembly units, exhibiting the defect;
• and
• in response to the count of assembly units falling below a threshold count of assembly units, recommending removal of the first inspection stage.

A method comprising:

• accessing a defect log associated with a first assembly unit in a first set of assembly units;
• deriving a location of a defect on the first assembly unit based on the defect log;
• isolating a first set of visual features spatially proximal the location of the defect on the first assembly unit;
• isolating a second set of nonvisual features associated with the defect according to the defect log;
• for each visual feature in the first set of visual features, calculating a first correlation, in a first set of correlations, between the visual feature and the defect;
• for each non-visual feature in the second set of non-visual features, calculating a second correlation, in a second set of correlations, between the non-visual feature and the defect;
• assembling the first set of correlations and the second set of correlations into a correlation matrix;
• isolating a first subset of features, in the first set of visual features and the second set of nonvisual features, corresponding to correlations in the correlation matrix exceeding a threshold correlation;
• generating a prediction of a root cause of the defect, the root cause specifying the first subset of features;
• and
• serving the prediction of the root cause of the defect to an operator portal.

The method of claim, further comprising:

• identifying a first inspection stage associated with detection of the defect according to the defect log;
• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• calculating a count of intermediate assembly stages between the first assembly stage, associated with the defect, and the first inspection stage;
• and
• in response to the count of intermediate assembly stages exceeding a threshold count, recommending installation of the first inspection stage immediately succeeding the first assembly stage.

The method of claim, further comprising:

• identifying a first inspection stage associated with detection of the defect according to the defect log;
• identifying a first assembly stage, in the set of assembly processes, associated with the defect based on the first subset of features;
• calculating a count of intermediate assembly stages between the first assembly stage, associated with the defect, and the first inspection stage;
• and
• in response to the count of intermediate assembly stages exceeding a threshold count, recommending installation of the first inspection stage immediately succeeding the first assembly stage.

The method of claim, further comprising:

• identifying a first subset of assembly units, in the first set of assembly units manufactured at a first manufacturing facility, exhibiting the first defect;
• identifying a first inspection station, in the first manufacturing facility, associated with detection of the first defect;
• identifying a second subset of assembly units, in a second set of assembly units manufactured at a second manufacturing facility, exhibiting the first defect;
• identifying a second inspection station, in the second manufacturing facility, associated with detection of the first defect;
• and
• in response to the second inspection station preceding the first inspection station in an assembly sequence for manufacturing of assembly units, recommending relocation of the first inspection station to a first location corresponding to a second location of the second inspection station in the assembly sequence.

A method comprising:

• accessing a corpus of defect logs associated with a first set of assembly units manufactured at a first manufacturing facility and specifying a first corpus of defects associated with the first set of assembly units;
• extracting a corpus of sensor data, captured by sensors at a set of inspection stations during manufacture of the first set of assembly units, from the corpus of defect logs;
• isolating a set of sensors associated with detection of the first corpus of defects based on the corpus of sensor data;
• for each sensor in the set of sensors, calculating a resource score proportional to a count of defects detected by the sensor;
• isolating a subset of sensors in the set of sensors, the subset of sensors exhibiting resource scores exceeding a threshold resource score;
• accessing an assembly configuration associated with a second manufacturing facility distinct from the first manufacturing facility;
• mapping the subset of sensors to corresponding inspection stages at the second manufacturing facility based on the assembly configuration;
• and
• recommending installation of the subset of sensors, at corresponding inspection stages, at the second manufacturing facility.

The method of claim, further comprising:

• accessing a second corpus of defect logs associated with a second set of assembly units manufactured at the second manufacturing facility and specifying a second corpus of defects associated with the second set of assembly units;
• identifying a first defect, in the second corpus of defects, absent from the first corpus of defects;
• isolating a defect log, in the second corpus of defect logs, specifying the first defect;
• deriving a location of the first defect on a first assembly unit, in the second set of assembly units, based on the defect log;
• isolating a first set of features associated with the location of the first defect on the first assembly unit;
• accessing an assembly graph associated with the second set of assembly units and defining a set of assembly processes, for manufacturing of the set of assembly units, and corresponding defects;
• defining a bounded region of the assembly graph, comprising a first subset of nodes and a first subset of edges, based on the first set of features;
• isolating a first set of candidate features defined in the bounded region of the assembly graph;
• based on the assembly graph:
• for each feature in the set of candidate features:
• generating a correlation, in a set of correlations, between the candidate feature and the defect;
• and
• assembling the set of correlations into a correlation matrix;
• isolating a first subset of features, in the set of candidate features, exhibiting correlations, in the set of correlations, exceeding a threshold correlation;
• generating a prediction of a root cause of the defect, the root cause specifying the first subset of features;
• and
• serving the prediction of the root cause of the defect to an operator portal.