Vehicle Head-Up Display Calibration Using Real-World Scene Features
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Solution Overview
Problem
Current head-up displays in vehicles face challenges in calibration, requiring alignment fixtures and specific physical targets, which are cumbersome and costly, and struggle to efficiently project high-contrast, real-time information within the driver's field of view while accounting for the vehicle's windscreen shape.
Innovation Solution
A method for in-situ calibration of head-up displays using vehicle sensors to identify suitable features in the real-world scene, allowing end-users to adjust projected imagery through user inputs, and a holographic projector system that uses computer-generated holograms to create a high-contrast, real-time virtual image overlay compatible with laser light sources, capable of compensating for windscreen shape and providing augmented reality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional calibration procedures using alignment fixtures and physical targets are used, then calibration accuracy can be achieved, but device complexity and production costs increase
Solution Approach 1:
The patent uses virtual images created by the HUD system itself as calibration targets, replacing physical alignment fixtures. The system projects virtual images onto the windscreen and uses sensors to detect their positions, creating a self-contained calibration process that eliminates external calibration equipment.
Solution Approach 2:
The HUD system performs calibration using its own projection capabilities and the vehicle's existing sensor system. The calibration process is self-service in that the system uses its own output (virtual images) as the input for measurement, eliminating the need for separate calibration devices.
2Measurement precision
If conventional calibration procedures are used, then calibration can be performed, but ease of operation deteriorates due to requiring specific physical targets and fixtures
Solution Approach 1:
The system uses virtual representations of calibration targets projected by the HUD itself, eliminating the need for physical targets. This makes calibration easier to perform while maintaining accuracy, as the virtual targets can be generated on-demand without requiring external equipment.
3Illumination intensity
If holographic projection with laser light sources is used, then contrast ratio and real-time performance are improved, but manufacturing precision requirements increase to account for windscreen shape variations
Solution Approach 1:
The system dynamically adjusts holographic projection parameters based on detected windscreen characteristics. By using sensors to measure the actual windscreen geometry and modifying the holographic projection accordingly, the system maintains high contrast ratio while compensating for manufacturing variations in the windscreen.
Solution Approach 2:
The system uses sensor feedback to detect the position and shape of the windscreen, then adjusts the holographic projection in real-time. This closed-loop approach allows the system to maintain high image quality and contrast ratio despite variations in windscreen manufacturing.
4Adaptability or versatility
If virtual images are projected onto the windscreen, then information can be displayed in the driver's field of view, but measurement precision deteriorates due to windscreen shape and position variations
Solution Approach 1:
The system dynamically modifies virtual image projection parameters based on real-time detection of windscreen position and shape. This allows the system to maintain precise virtual image positioning while adapting to different windscreen configurations and ensuring the information remains accurately positioned in the driver's field of view.
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 efficient, user-based calibration without alignment fixtures, enhances contrast ratio, and provides real-time, accurately positioned virtual information within the driver's field of view, improving the overall user experience and reducing production costs.
Implementation Method 1
Light modulation may be achieved using electrically-addressable liquid crystals, optically-addressable liquid crystals or micro-mirrors, for example.
Implementation Method 2
The pixels of the display may display a diffractive pattern or structure that diffracts light. The diffracted light may form an image at a plane spatially separated from the display device.
Implementation Method 3
Light scattered from an object contains both amplitude and phase information. This amplitude and phase information can be captured on, for example, a photosensitive plate by well-known interference techniques to form a holographic recording, or 'hologram'
Implementation Method 4
The hologram may be reconstructed by illumination with suitable light to form a two-dimensional or three-dimensional holographic reconstruction, or replay image, representative of the original object.
Data Source
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AI summary
A method for an end-user to perform in-situ calibration of the imagery of a head-up display in a vehicle. A first step comprises obtaining information on the real-world scene within a field of view of the head-up display from a vehicle sensor system of the vehicle. A second step comprises using the information obtained from the vehicle sensor system to identify at least one feature in the field of view satisfying a suitability criterion for the head-up display calibration mode. A third step comprises projecting an image using the head-up display. The image comprises an image element corresponding to each feature. A fourth step comprises receiving at least one first user-input and changing the image in response to each first user-input.