Depth-Sensing Automatic Door Control for Fewer False Openings

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Solution Overview

Problem

Conventional automatic door sensors often trigger unnecessarily when pedestrians are merely standing near or passing by, leading to energy loss, noise, and reduced door lifetime.

Innovation Solution

A 3D depth sensor system that generates spatial maps to track individuals' trajectories, distinguishing between those entering/exiting and those merely passing, and only activates the door when intended passage is detected.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional motion sensors are used to detect pedestrians near the door, then the doors can be activated automatically, but the doors open needlessly when pedestrians are merely standing near or passing by

Engineering Contradiction:
Improveautomatic door activationVSAvoidenergy loss from unnecessary door openings
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent transitions from conventional 2D motion detection to 3D spatial mapping using depth sensors. The system creates depth maps and tracks pedestrian trajectories in three-dimensional space, enabling distinction between pedestrians approaching the door and those merely passing by, thereby reducing unnecessary door openings and energy loss

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

Solution Approach 2:

The patent replaces conventional mechanical motion sensors with optical/electromagnetic sensing systems. Specifically, it uses depth sensors (such as LIDAR or structured light sensors) to generate spatial maps and track pedestrian motion, providing more precise detection capabilities that differentiate between intentional approach and incidental presence

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If conventional motion sensors trigger doors for any pedestrian presence, then door activation is simple, but noise increases and door lifetime reduces

Engineering Contradiction:
Improvesimple door activationVSAvoiddoor lifetime
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

By implementing 3D spatial tracking and trajectory analysis, the system gains the ability to distinguish between pedestrians approaching the door and those passing by. This dimensional enhancement in detection capability allows the door to remain closed for non-threatening passes while still opening for actual approach, thereby extending door lifetime and reducing noise from unnecessary operations

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

3Loss of energy

If depth sensors with spatial mapping are used to track individuals, then unnecessary door openings are reduced, but device complexity increases

Engineering Contradiction:
Improveenergy conservation from reduced door openingsVSAvoidsensor assembly complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent employs a sensor assembly where a single depth sensor performs multiple functions: generating depth maps, tracking pedestrian trajectories, determining spatial relationships, and triggering door opening decisions. This multi-functionality consolidates what would otherwise require multiple separate sensors and processing systems into one integrated unit, thereby managing complexity while achieving energy conservation

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Reduces unnecessary door openings, conserving energy, minimizing noise, and extending door lifespan by ensuring doors open only when intended entry or exit occurs.

Implementation Method 1

an emitter configured to send out signals toward the individual proximate to the aperture, a receiver configured to receive reflections of the signals which are reflected off of the individual

Methodology Applied
Scientific EffectInfrared reflection: Infrared Radiation

Data Source

PatentEP3404184B1Door system comprising a depth sensor
Publication Date: 2026.03.11 OTIS ELEVATOR CO
  • EP3404184B1 patent drawingFigure 1~3
  • EP3404184B1 patent drawingFigure 4~5D
  • EP3404184B1 patent drawingFigure 6~8

AI summary

A door system (10) is provided and includes a door assembly (13) operable to assume an open position at which an aperture (12) is opened and a closed position at which the aperture (12) is closed, a sensor assembly (14) and a controller (15). The controller (15) is coupled to the door assembly (13) and configured to instruct the door assembly (13) to normally assume the closed position and to assume the open position in accordance with an open signal being issued by the sensor assembly (14). The sensor assembly (14) is configured to track the individual, determine whether the individual is likely to be approaching the aperture (12) from the tracking and issue the open signal in accordance with a determination that the individual is likely to be approaching the aperture (12).