Dynamic Camera-Projector Calibration Using Epipolar Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Projector and camera pairs in applications like automotive headlights face misalignment issues due to mechanical stress and environmental factors, leading to potential glare for drivers, which existing alignment methods fail to address effectively during vehicle use.
Innovation Solution
A system that projects a test pattern image, captures it with a camera, and uses a controller to determine calibration matrices and epipolar lines to adjust the camera or projector positions dynamically, ensuring accurate alignment and minimizing glare by iteratively calculating and applying correction factors based on cost functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If initial alignment is performed at factory or dealership, then projector and camera are initially aligned, but misalignment occurs due to mechanical stress and environmental factors during vehicle use
Solution Approach 1:
The patent implements dynamic calibration that continuously monitors and adjusts the alignment between projector and camera during vehicle operation. The system detects misalignment caused by mechanical stress and environmental factors, then automatically recalibrates to maintain reliable alignment without requiring manual intervention at dealerships.
Solution Approach 2:
The system uses feedback from the camera to monitor the projected pattern and detect misalignment. The controller processes the captured images, compares them with expected patterns, and adjusts the projector or camera position accordingly, creating a closed-loop alignment maintenance system that adapts to changing conditions during vehicle use.
2Manufacturing precision
If manual alignment adjustment is required, then alignment can be corrected, but the process is time-consuming and requires dealership intervention
Solution Approach 1:
The calibration system performs automatic self-adjustment without requiring dealership intervention. The controller independently processes camera captures, calculates misalignment, and executes correction commands to the projector or camera actuators, enabling the system to maintain alignment precision autonomously and eliminating time lost in manual adjustments.
3Reliability
If calibration is performed dynamically during use, then alignment is maintained, but additional computational processing is required
Solution Approach 1:
The system uses a test pattern image with known geometric characteristics as a preliminary reference. By projecting and capturing this predetermined pattern, the system establishes a baseline for detecting misalignment. This preliminary action simplifies the subsequent calibration computations by providing a known reference framework for calculating and correcting alignment deviations.
Data Source
AI summary
Described examples include a system including a projector configured to project a test pattern image, the test pattern image having at least two elements; a camera configured to capture the test pattern image; and a controller coupled to the projector and to the camera. The controller is configured to obtain a first calibration matrix between the projector and the camera for the at least two elements; determine at least two epipolar lines based on the first calibration matrix and the test pattern image; determine a cost function based on the at least two epipolar lines and the at least two elements in the test pattern image as captured by the camera; and determine a second calibration matrix responsive to the cost function, wherein at least one of a camera position of the camera or a projector position of the projector is adjusted responsive to the second calibration matrix.