Vision Machine Light Source Layout for Wider TOF Sensing
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Solution Overview
Problem
Vision machines, particularly those with TOF cameras installed on mobile robots, suffer from blind zones and interference signals due to the positioning of infrared light sources, leading to inaccurate obstacle detection and limited viewing angles.
Innovation Solution
A control method for light sources in vision machines that involves activating multiple light sources distributed around the lens, selectively based on spatial information of sensed objects, to enhance viewing angle and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single infrared light source is arranged below the lens with axis parallel to optical axis, then the structure is simple and compact, but the viewing angle is limited and blind zones exist
Solution Approach 1:
The single light source is segmented into multiple light sources (at least two) arranged around the lens periphery. Each light source covers a specific angular sector, collectively providing 360-degree coverage while eliminating blind zones. This segmentation resolves the contradiction by trading structural complexity for significantly improved viewing angle adaptability.
Solution Approach 2:
The light sources are arranged in a circular pattern around the lens periphery, transitioning from a single-axis arrangement to a multi-dimensional circular distribution. This dimensional change allows light emission from multiple angular directions simultaneously, expanding the viewing angle from a limited sector to full 360-degree coverage while maintaining compact structure.
2Device complexity
If the infrared light source is positioned below the lens, then the design is compact, but the lens can only sense the illuminated surface, creating blind spots
Solution Approach 1:
The illumination task is segmented across multiple light sources positioned at different angular locations around the lens. Each light source illuminates a specific spatial sector, ensuring complete coverage of the object surface from multiple angles. This eliminates blind spots while maintaining compact design through the modular arrangement of light sources.
Solution Approach 2:
Multiple light sources are merged into a unified circular arrangement around the lens, working cooperatively to provide comprehensive illumination. The combined effect of all light sources ensures that every portion of the object surface receives illumination from at least one light source, eliminating blind spots while preserving compact form factor.
3Device complexity
If the light source axis is parallel to the lens optical axis, then the alignment is simple, but light reflects to the ground forming interference signals
Solution Approach 1:
The single aligned light source is segmented into multiple light sources arranged around the lens periphery. Each light source is angled relative to the optical axis, directing light toward specific angular sectors. This segmentation eliminates ground reflection interference by ensuring light paths do not parallel the optical axis, while maintaining alignment simplicity through symmetric angular distribution.
Solution Approach 2:
The light sources are positioned asymmetrically relative to the optical axis, with each light source angled to illuminate its specific sector. This asymmetric angular arrangement prevents light from traveling parallel to the optical axis and reflecting to the ground, thereby eliminating interference signals while preserving alignment simplicity through geometric design.
4Device complexity
If only overlapping FOV areas are used for sensing, then the system is simple, but large blind zones exist in the traveling direction
Solution Approach 1:
The sensing system is segmented into multiple light source zones, each responsible for illuminating and enabling detection in a specific angular sector. This segmentation extends detection coverage beyond the simple overlapping FOV area by assigning dedicated light sources to previously blind sectors, eliminating blind zones in the traveling direction while maintaining simple system architecture.
Solution Approach 2:
The sensing coverage is expanded from two-dimensional FOV overlap to three-dimensional omnidirectional coverage by arranging light sources in a circular pattern around the lens. This dimensional expansion allows detection in all angular directions, eliminating blind zones in the traveling direction while keeping the sensing system simple through uniform geometric distribution.
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
The method expands the field of view, reduces interference signals, and improves the sensing range and accuracy of vision machines by providing flexible light illumination based on environmental requirements, enabling better obstacle detection and depth information acquisition.
Implementation Method 1
an image sensor module for converting optical signals into electrical signals
Implementation Method 2
determines a distance between the object and the lens by calculating TOFs of the emitted light and the received light
Data Source
AI summary
A control method for light sources of a vision machine and the vision machine. The control method includes the following steps: activating at least one first light source among n light sources to sense spatial information of an object in a field of view; and selectively activating the n light sources according to the spatial information of a sensed object; wherein the n light sources are distributed on a periphery of a front mirror surface of a lens of the vision machine, and n is a natural number greater than or equal to 2. The embodiment of the present disclosure enlarges the field of view of the vision machine, capable of providing corresponding light illumination based on environmental requirements, reducing the interference signal caused by reflection of a single light source, expanding the sensing range of the vision machine, and improving the sensing ability.