Multi-Wavelength Object Tracking with Band-Pass Filters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positional tracking methods in virtual reality systems face challenges with accurate detection and tracking of light-emitting objects due to interference from ambient lights, especially when using single wavelength light sources, which can lead to inaccurate identification and tracking, particularly in environments with multiple devices.
Innovation Solution
The use of a system with two cameras capturing images of a trackable object emitting light of different wavelengths, where each camera is equipped with a band-pass filter to isolate specific wavelengths, allowing for more robust object identification and tracking by reducing ambient light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a visible light source is used for tracking, then the trackable device can be detected by cameras, but ambient lights such as sunlight, fluorescent lamp lights, or LED lights can obfuscate the signal and affect accurate detection and tracking
Solution Approach 1:
The patent segments the light signal into multiple discrete wavelength components by using multiple LEDs emitting at different wavelengths. Each wavelength can be independently detected and processed, allowing the system to distinguish the trackable device signal from ambient light by analyzing the spectral composition rather than relying on a single broadband visible light source.
Solution Approach 2:
The patent changes the parameter of light wavelength by using multiple LEDs that emit at different specific wavelengths. This allows the system to select wavelengths that are less susceptible to ambient light interference and to use wavelength discrimination as a method to filter out background light, thereby improving detection accuracy.
2Object-affected harmful factors
If an infrared light source is used for tracking, then ambient light interference is reduced, but when multiple devices are applied in the same scene, it becomes hard to identify each device
Solution Approach 1:
The patent applies local quality by assigning different wavelength characteristics to different devices or different parts of the tracking system. Each LED emits at a specific wavelength, creating a unique spectral signature for each light source. This allows individual device identification while maintaining the benefits of infrared light for reducing ambient light interference.
Solution Approach 2:
The patent uses a composite light source consisting of multiple LEDs with different wavelength emissions. This composite approach combines the advantages of infrared light (reduced ambient interference) with the ability to encode identification information through wavelength differentiation, allowing both tracking and identification functions to be performed simultaneously.
3Loss of information
If multiple infrared-LEDs groups with twinkle patterns are used to identify each device, then device identification is possible, but extra time is needed to form the twinkle pattern which increases total processing time and produces time delays
Solution Approach 1:
The patent uses periodic action through controlled LED activation sequences where different LEDs are turned on and off in specific patterns. This allows encoding of identification information in the temporal domain without requiring complex twinkle patterns, reducing processing time while maintaining device distinguishability.
Solution Approach 2:
The patent changes the temporal parameter of light emission by using different duty cycles, pulse widths, or activation sequences for different LEDs. This enables device identification through time-coded signals that can be detected and decoded rapidly, avoiding the time-consuming formation of complex twinkle patterns while preserving identification capability.
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
This approach enhances the accuracy and reliability of object tracking by minimizing interference from ambient light signals, enabling precise identification and location determination of objects in virtual reality environments with low latency.
Implementation Method 1
each camera is equipped with a band-pass filter to isolate specific wavelengths
Implementation Method 2
a trackable object emitting light of different wavelengths
Data Source
AI summary
An object identifying and tracking device is provided. The device includes a first image capturer to capture a first raw image of an object, a second image capturer to capture a second raw image of the object, a first processor, a second processor and a post processor. The object includes a first light source emitting light of a first wavelength and a second light source emitting light of a second wavelength. The first processor and the second processor respectively receive the first and the second raw images and respectively extract a first group of information associated with the light of the first wavelength and a second group of information associated with the light of the second wavelength emitted from the object. The post processor processes the first group of information and the second group of information to obtain a third group of information.