Inspection Device Pose Calibration With Marker-Based Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the pose of inspection devices in vehicle inspection systems, such as outside-in and inside-out motion tracking, are unsuitable for mobile robot inspection due to complexity, high computational requirements, measurement errors, and lack of standardization, making it difficult to autonomously inspect vehicles without manual input and complex setups.
Innovation Solution
A mobile inspection device equipped with a movable positioning arm, multiple cameras with narrow fields of view, and calibration targets or markers in the measuring space, allowing for autonomous navigation and precise pose determination using an absolute coordinate system, combined with a digital twin creation for comprehensive vehicle inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If outside-in motion tracking with multiple cameras is used, then measurement coverage is improved, but device complexity and processing requirements increase significantly
Solution Approach 1:
The patent inverts the traditional outside-in motion tracking approach by implementing inside-out motion tracking, where the camera moves with the inspection device and tracks stationary markers in the environment. This reversal reduces the number of cameras needed from multiple static cameras to a single mobile camera, significantly simplifying device complexity while maintaining measurement coverage through the mobile platform's movement.
Solution Approach 2:
The patent employs dynamic positioning where the camera is mounted on a mobile inspection device that moves through the measurement space. Instead of using multiple static cameras to achieve comprehensive coverage, a single dynamic camera captures images from various positions, reducing system complexity while maintaining the ability to measure the entire vehicle.
2Device complexity
If inside-out motion tracking with a single camera is used, then device complexity is reduced, but measurement accuracy deteriorates due to obscured areas and reflective surfaces
Solution Approach 1:
The patent introduces markers as intermediary objects that are attached to the vehicle being inspected. These markers serve as reliable reference points that the camera can track accurately, even in challenging conditions with obscured areas or reflective surfaces. The markers act as mediators between the camera and the vehicle features, ensuring consistent and accurate measurement points regardless of surface properties.
Solution Approach 2:
The patent changes the measurement parameters by using specifically designed markers with known geometric properties and high contrast characteristics. These markers have controlled reflectivity and geometry that optimize their detectability by the camera, transforming the measurement challenge into a controlled parameter space where accuracy can be maintained despite the mobile camera's limitations.
3Extent of automation
If markers are used for motion tracking, then pose determination is enabled, but measurement accuracy deteriorates due to reflections on reflective surfaces
Solution Approach 1:
The patent converts the harmful effect of reflective surfaces into a benefit by using markers with controlled reflective properties. Instead of trying to avoid reflections, the system uses markers whose reflectivity is optimized for camera detection. The markers' reflective characteristics become an asset rather than a liability, enabling reliable detection even on vehicles with reflective paint or surfaces.
Solution Approach 2:
The patent uses simple, inexpensive markers that can be temporarily attached to the vehicle for the duration of the inspection. These markers are straightforward geometric shapes with high-contrast colors or reflective properties, designed to be easily detected by the camera. Their simplicity and low cost allow for multiple markers to be placed on the vehicle without significant expense or complexity.
4Area of stationary object
If fisheye lens camera is used, then wide field of view is achieved, but measurement accuracy deteriorates at image edges
Solution Approach 1:
The patent segments the measurement task into multiple localized measurements rather than attempting to capture the entire vehicle in a single wide-angle image. The mobile camera moves to different positions, capturing multiple images of different regions with acceptable edge distortion. This segmentation approach allows the use of standard lenses instead of fisheye lenses, maintaining measurement accuracy across all captured regions.
Solution Approach 2:
The patent uses partial action by capturing multiple partial views of the vehicle from different positions rather than attempting to capture the entire vehicle in one view. Each individual image captures only a portion of the vehicle, but the combination of multiple images provides complete coverage with high accuracy in each region, avoiding the edge distortion problems of wide-angle lenses.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables autonomous, precise, and cost-effective vehicle inspection by eliminating the need for complex setups, reducing measurement errors, and providing a unified digital representation for analysis.
Implementation Method 1
The camera can use various markers statically attached to its surroundings to determine its position. These markers can be LEDs, reflective markers, or laser emitters.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method for determining the pose of an inspection device, comprising the steps of: calibrating a camera unit by capturing a calibration target or mark from different angles and distances; calibrating a measuring head by simultaneously capturing a calibration target or mark with two or more cameras of the camera unit; calibrating a measuring chamber by optically measuring the relative position of the calibration target or mark; creating a coordinate system that includes the positions of all calibration targets or marks.