Polarized Light Receiver Layout for Multipath Distance Sensing
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Solution Overview
Problem
Optoelectronic sensors face challenges in distance measurement due to multipath reception, leading to measurement errors, artifacts, and limited dynamic range, especially with high-contrast or low-contrast objects.
Innovation Solution
The sensor employs a light receiver with at least one polarization element that directs received light with different polarizations to separate receiving elements, allowing each element to receive light from a single object, resolving ambiguity and enabling separate evaluation for accurate distance determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple receiving elements are used for distance measurement, then measurement coverage and depth image generation are improved, but measurement errors and artifacts increase due to multipath reception
Solution Approach 1:
The receiving elements are divided into multiple polarization groups, where each group is associated with a specific polarization state. This segmentation allows the sensor to separate multipath reception signals based on their different polarization characteristics, thereby maintaining measurement coverage while improving distance measurement accuracy by preventing signal overlap from different objects
Solution Approach 2:
A polarization element is introduced as an intermediary component between the receiving elements and the environment. This polarization element modulates the polarization state of received light signals, enabling the system to distinguish between direct path and multipath reception signals through polarization differentiation, thus resolving measurement ambiguities
2Device complexity
If conventional receiving elements are used without polarization separation, then device complexity is low, but dynamic range is limited and depth resolution deteriorates
Solution Approach 1:
The receiving elements are designed to handle multiple polarization states simultaneously through association with polarization elements. Each receiving element can process signals with different polarization characteristics, enabling the system to accommodate a wider dynamic range and handle high-contrast or low-contrast objects effectively without significantly increasing structural complexity
3Quantity of substance
If received light from different objects is directed to the same receiving element, then signal collection efficiency is high, but measurement ambiguity and ghost images increase
Solution Approach 1:
Different polarization groups are assigned to different spatial regions or receiving elements based on the local polarization characteristics of expected targets. This local quality differentiation enables the system to maintain high signal collection efficiency for relevant objects while filtering out multipath reception signals with different polarization states, thereby preventing measurement ambiguity and ghost images
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 improves measurement accuracy by resolving multipath reception issues, enhancing depth resolution and dynamic range through separate evaluation of polarized light from different objects.
Implementation Method 1
the light receiver comprises at least one polarization element which is designed to supply received light with a first polarization to one (first) of the receiving elements and received light with a second polarization, which is different from the first polarization, to another (second) of the receiving elements
Implementation Method 2
a light source configured to convert a transmitted signal into transmitted light and emit the transmitted light into an environment
Implementation Method 3
the receiving elements serve to determine the time of light travel to the object. To this end, the receiving elements preferably detect a phase difference between the transmitted signal and/or the transmitted light on the one hand, and the received light (and, if applicable, a received signal generated from the received light) on the other
Data Source
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AI summary
The invention relates to an optoelectronic sensor for distance measurement, comprising a light source configured to convert a transmitted signal into transmitted light and to emit the transmitted light into an environment, and a light receiver which receives transmitted light reflected from objects in the environment as received light, wherein the light receiver has several receiving elements for distance measurement. The sensor is characterized in that the light receiver comprises at least one polarization element configured to supply received light with a first polarization to one of the receiving elements and received light with a second polarization, which differs from the first polarization, to another of the receiving elements.