Vehicle inspection system and method with adaptive template matching and temporal defect tracking
A vehicle inspection system captures multi-view images and retrieves vehicle-specific reference templates that evolve through gated learning based on validated inspection outcomes. The system computes multiple spatially-registered similarity maps, generates deviation maps, and compares against prior inspections to distinguish persistent defects from transient conditions. The adaptive template approach reduces false positives while maintaining sensitivity to genuine defects, providing accurate temporal defect tracking for fleet management applications.
1 . A vehicle inspection system comprising:
an imaging assembly disposed around a vehicle inspection lane, the imaging assembly including a plurality of cameras positioned to capture multi-view images of at least a portion of a vehicle;
a memory storing instructions;
one or more processors configured for executing the instructions to:
retrieve a vehicle identifier of the vehicle;
determine, from the multi-view images, a spatial pose of the vehicle relative to the imaging assembly;
retrieve, from a template library, a reference template corresponding to the vehicle identifier;
compute a geometric transformation that aliens the reference template to the determined spatial pose;
compute, between the aligned reference template and the captured images, one or more spatially-registered similarity maps;
generate a deviation map from the one or more similarity maps;
compare the deviation map against deviation maps from prior inspections of the same vehicle to distinguish persistent anomalies from transient conditions; and
generate an inspection report identifying classified vehicle defects with spatial locations and severity scores,
wherein the imaging assembly includes polarization-controlled imaging sensors, and wherein the one or more processors are configured to:
separate diffuse and specular reflection components from the captured images,
compute a first similarity map on the diffuse reflection components to detect color and texture anomalies, and
compute a second similarity map on the specular reflection patterns to detect surface geometry deviations.
2 . The system of claim 1 , wherein the one or more processors are further configured to apply photometric normalization to at least one of the reference template and the captured images to compensate for illumination differences.
3 . The system of claim 1 , wherein the one or more spatially-registered similarity maps include two or more of:
a deep-feature correlation map derived from convolutional neural network features,
an edge-distance map computed from distance transforms of edge maps, and
a photometrically-normalized intensity correlation map.
4 . The system of claim 3 , wherein the one or more spatially-registered similarity maps further include a phase-only correlation map computed to capture structural similarity independent of intensity variations.
5 . The system of claim 1 , wherein the reference template is a per-vehicle template associated with the vehicle identifier, and wherein the one or more processors are further configured to update the per-vehicle template by incorporating regions confirmed as normal and excluding regions confirmed as defective.
6 . The system of claim 5 , wherein the one or more processors are configured to initialize the per-vehicle template at a first inspection visit and evolve the per-vehicle template across subsequent inspections using gated learning based on inspection outcomes.
7 . The system of claim 1 , wherein the template library includes both:
a per-vehicle template specific to the vehicle identifier, and
a class template derived from fleet-level statistical aggregation of multiple vehicles of a same class, and
wherein the one or more processors weight evidence from the per-vehicle template and the class template using learned uncertainty weights.
8 . The system of claim 7 , wherein the one or more processors apply region-specific adaptive thresholds to the deviation map based on fleet-level variance priors that encode expected variability for corresponding regions of the vehicle class.
9 . The system of claim 8 , wherein the fleet-level variance priors include seasonal priors that modulate expected variance based on time of year and geographic region to account for weather-related conditions.
10 . The system of claim 1 , wherein retrieving the reference template comprises synthesizing the reference template by:
accessing a three-dimensional vehicle model corresponding to the vehicle identifier,
rendering the three-dimensional vehicle model under illumination conditions estimated from the captured images, and
projecting the rendered model to viewpoints corresponding to the plurality of cameras.
11 . The system of claim 1 , wherein the plurality of cameras include undercarriage imaging sensors, and wherein the one or more processors are configured to:
register sequential undercarriage frames captured as the vehicle moves through the inspection lane,
construct an undercarriage panorama in a vehicle-centric coordinate frame, and
detect at least one of missing components, foreign objects, loose components, and fluid leaks by comparing the undercarriage panorama to an undercarriage reference template.
12 . The system of claim 1 , wherein the one or more processors are further configured to:
receive one or more exemplar image patches depicting a target defect type,
compute exemplar-conditioned correlation between features of the exemplar image patches and features of the captured images, and
perform bounding-box regression conditioned on the exemplar-conditioned correlation to detect instances of the target defect type without retraining a detection model.
13 . The system of claim 12 , wherein the one or more exemplar image patches are automatically mined from confirmed defects in prior inspections of a fleet of vehicles.
14 . The system of claim 1 , wherein computing the geometric transformation includes:
computing a coarse translational alignment using phase-only correlation,
refining the coarse alignment to an affine transformation using enhanced correlation coefficient optimization, and
applying a local non-rigid refinement to accommodate vehicle deformations.
15 . The system of claim 1 , wherein the imaging assembly further includes at least one depth sensor, and wherein the one or more processors are configured to:
back-project candidate defect regions to three-dimensional space using depth data and camera calibration parameters, and
require corroboration of a defect from multiple camera viewpoints based on epipolar geometry before classifying as a confirmed defect.
16 . The system of claim 15 , wherein the one or more processors compute severity scores based on at least one of:
depth or displacement magnitude measured from the at least one depth sensor, affected surface area,
temporal persistence across multiple inspections, and
deviation magnitude in the deviation map.
17 . A method for automated vehicle inspection, comprising:
capturing, by an imaging assembly having polarization-controlled imaging sensors, multi-view images of a vehicle;
retrieving a vehicle identifier and determining a spatial pose of the vehicle;
retrieving, from a template library, a reference template corresponding to the vehicle identifier;
aligning the reference template to the determined spatial pose by computing a geometric transformation;
computing, between the aligned reference template and the captured images, a plurality of spatially-registered similarity maps including at least a deep-feature correlation map and an edge-distance map;
separating diffuse and specular reflection components from the captured images;
computing a first similarity map on the diffuse reflection components to detect color and texture anomalies;
computing a second similarity map on the specular reflection patterns to detect surface geometry deviations
generating a deviation map by fusing the plurality of similarity maps;
comparing the deviation map against prior deviation maps from previous inspections of the vehicle to identify persistent anomalies; and
generating an inspection report with classified defects, spatial locations, and severity scores.
18 . The method of claim 17 , further comprising:
updating the reference template based on confirmed inspection outcomes by:
incorporating regions confirmed as defect-free into the reference template,
excluding regions confirmed as defective from the reference template, and
evolving the reference template across multiple inspections of the vehicle using gated learning;
wherein the reference template is a per-vehicle template specific to the vehicle identifier.
19 . The method of claim 17 , further comprising:
receiving one or more exemplar patches depicting a specific defect type;
computing spatial correlation between features extracted from the exemplar patches and features extracted from the captured images; and
localizing additional instances of the specific defect type using template-conditioned regression based on the spatial correlation, thereby enabling detection of new defect types without retraining a detection model.