Laser Line Scanner Alignment Using Reference Points and a Common Vector
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for aligning laser line scanners in laser measurement systems are inaccurate and time-consuming, leading to skew and divergent scanned data, particularly when scanning long and skinny objects, and do not effectively address potential skew during alignment.
Innovation Solution
Utilizing a common direction vector and an alignment artifact with defined reference points to determine transformation matrices for laser line scanners, reducing processing time and improving alignment accuracy by using linear regression to align scanners with the global reference frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current alignment methods are used for laser line scanners, then alignment can be performed, but the alignment is inaccurate and time-consuming
Solution Approach 1:
The system performs preliminary alignment by scanning an alignment artifact with known reference points before actual measurement. The controller pre-calculates transformation matrices using these reference points to establish accurate coordinate transformations between scanner reference frames and the global reference frame, eliminating the need for time-consuming iterative alignment during actual measurement.
Solution Approach 2:
The patent replaces manual or mechanical alignment adjustment methods with an automated computational approach. The controller uses software-based coordinate transformation and mathematical optimization to automatically determine the precise position and orientation of each laser line scanner, substituting physical adjustment mechanisms with digital calculation and transformation matrices.
2Productivity
If laser line scanners are aligned without a common direction vector, then alignment can be performed quickly, but skew and divergent scanned data occur
Solution Approach 1:
The patent introduces a common direction vector that serves multiple functions simultaneously: it defines the scan direction for all laser line scanners, establishes the orientation of the alignment artifact, and serves as a reference for calculating transformation matrices. This universal reference ensures all scanners are aligned consistently without requiring separate alignment procedures for each scanner.
Solution Approach 2:
The system changes the alignment approach by introducing a common direction vector as a key parameter. Instead of allowing each scanner to have independent orientation parameters, the system constrains all scanners to share the same direction vector parameter, ensuring consistent scan directions while maintaining alignment speed through direct calculation rather than iterative adjustment.
3Measurement precision
If iterative guess and check methods are used for alignment, then alignment can be achieved, but excessive compute time and resources are consumed
Solution Approach 1:
The alignment artifact with its known reference points serves as a self-calibrating element. When scanned by the laser line scanners, the reference points automatically provide the information needed to calculate transformation matrices without requiring external intervention or iterative guessing. The system uses the inherent geometry of the alignment artifact to self-determine the correct alignment parameters.
Solution Approach 2:
The patent creates a digital copy of the alignment artifact's reference point locations in the global reference frame and compares it with the scanned positions. Instead of iteratively guessing the transformation, the system directly calculates the transformation matrix by matching the known reference point coordinates with their scanned counterparts, eliminating the need for repeated trial-and-error computations.
Data Source
AI summary
One example provides a laser measurement system comprising an alignment artifact attached to a global reference frame. The alignment artifact has features that define corresponding reference points. A controller is configured to obtain metadata comprising expected locations of the corresponding reference points for the features within a target view during a scan. The controller is also configured to obtain a raw point cloud of the alignment artifact within a scanner reference frame. The controller is further configured to determine scanned features from the raw point cloud, and locations of corresponding scanned reference points to form a set of scanned locations. The controller is also configured to determine a transformation matrix to transform coordinates between the scanner reference frame and the global reference frame based at least upon the set of expected locations, the set of scanned locations, and a common direction vector for a plurality of laser line scanners.