Laser Scanner Human Recognition Density Distribution Analysis

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Solution Overview

Problem

Existing human recognition sensors face challenges in accurately distinguishing human bodies from other objects in monitored areas, particularly due to limitations in height and width comparisons and background noise interference.

Innovation Solution

A method utilizing a laser scanner to generate multiple laser curtains, evaluating the density distribution of reflection points in an evaluation plane with a Z-axis representing height and a perpendicular axis representing width, and comparing these distributions to anthropometric parameters, such as head-to-shoulder ratios, to determine if a detected object is a human body, while integrating time and motion analysis to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional height and width comparison methods are used for human body recognition, then the device complexity is low, but the detection accuracy is insufficient due to inability to distinguish human bodies from other objects with similar dimensions

Engineering Contradiction:
Improvehuman body detection accuracyVSAvoidevaluation method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from traditional 2D height-width comparison to a density distribution analysis along the height direction (Z-axis). By evaluating the density of reflection points at different heights and comparing it to anthropometric parameters, the system adds a dimensional aspect of density analysis that enables more accurate human body identification without requiring complex multi-sensor arrays

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the evaluation parameter from simple geometric dimensions (height, width) to density distribution characteristics along the height axis. By analyzing how reflection point density varies with height and comparing peak positions to known human body proportions (head-to-shoulder ratio), the system achieves better discrimination accuracy while maintaining relatively simple evaluation logic

Inventive Principle:
Principle #35Parameter changes

2Reliability

If simple geometric comparison is used, then the processing speed is fast, but the reliability of human body identification is low due to background noise interference

Engineering Contradiction:
Improvehuman body identification reliabilityVSAvoiddetection processing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent evaluates density distribution along the height direction and identifies characteristic peaks corresponding to human body parts (head at top, shoulders below). By comparing the ratio of peak positions to anthropometric parameters, the system achieves reliable human body identification that is resistant to background noise, while maintaining efficient processing through a focused evaluation approach rather than comprehensive analysis

Inventive Principle:
Principle #35Parameter changes

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 significantly improves the accuracy of human detection by reliably distinguishing human bodies from other objects and reducing background noise, allowing for precise control applications like door operation and access management.

Implementation Method 1

each laser curtain is generated by multiple pulses evaluated by time of flight measurement of single pulses to generate the distance of the points of reflection with respect to the laser scanner position

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3610291B1Method of human body recognition and human body recognition sensor
Publication Date: 2022.12.21 BEA SA
  • EP3610291B1 patent drawingFigure 1
  • EP3610291B1 patent drawingFigure 2
  • EP3610291B1 patent drawingFigure 3

AI summary

The invention relates to a method of human body recognition by analysing a detected object (P) in a monitored area and deciding whether or not the detected object is a human being with a laser scanner (12) comprising: the laser scanner (12) generates at least one laser curtain ( 22, 32, 34), where each laser curtain (22, 32, 34) is generated by multiple pulses evaluated by time of flight (TOF) measurement of single pulses to generate the distance of the points of reflection with respect to the laser scanner position; combination of distances of the points of reflection with the direction of the pulse to retrieve a position in a predefined detection zone within a monitored area; projecting the points of reflection belonging to a detected object into an evaluation plane (EP) as evaluation objects (O1, O2), where the evaluation plane (EP) has a Z-axis that is related to the height and a perpendicular one to the Z-axis that is related to the width in the direction of the lateral extension of the laser curtain (22, 32, 34). The invention is characterized in that the evaluation plane (EP) is evaluated based on the density distribution of the points of reflection along the Z-axis and the evaluation result is compared to anthropometric parameters.