Depth Sensor Detection of Escalator Step Comb Plate Engagement

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Solution Overview

Problem

Existing passenger conveyor systems face safety risks due to the inability to timely detect abnormal engaging states between steps and comb plates, such as broken teeth or foreign matter, which can lead to accidents and damage.

Innovation Solution

An engaging state detection system utilizing depth sensing sensors and processing apparatuses that extract shape, texture, and position features to judge the normalcy of the engaging state, including the presence of passengers or articles, and detect foreign matter using optical flow methods to determine abnormal conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no detection system is installed, then the system structure is simple and cost is low, but safety cannot be ensured due to inability to detect broken teeth or foreign matter

Engineering Contradiction:
ImprovesafetyVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical inspection methods with an optical detection system using depth sensing sensors and image processing algorithms. The processing apparatus analyzes depth maps and extracted features (shape, texture, position) to automatically detect broken teeth and foreign matter, eliminating the need for complex mechanical inspection mechanisms while ensuring safety.

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

Solution Approach 2:

The detection system operates autonomously by continuously capturing depth maps, extracting features, and judging engaging states without human intervention. The system self-monitors the engaging portion between steps and comb plates, automatically identifying abnormalities and triggering alarms or stopping the conveyor when issues are detected.

Inventive Principle:
Principle #25Self-service

2Loss of time

If real-time detection is implemented, then abnormal states can be identified promptly, but processing time and computational resources increase

Engineering Contradiction:
Improveresponse timeVSAvoidprocessing resources
Core Design Contradiction:
Loss of timeVSUse of energy by stationary object

Solution Approach 1:

The system performs preliminary feature extraction and abnormal state judgment during the normal operation of the passenger conveyor, rather than conducting comprehensive inspections after potential failures occur. By continuously processing depth maps and extracting features in real-time, the system identifies broken teeth or foreign matter promptly, enabling timely response while optimizing processing efficiency through continuous operation.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If detection accuracy is improved through feature extraction, then identification precision increases, but the complexity of data processing increases

Engineering Contradiction:
Improvedetection accuracyVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the detection process into distinct functional modules: depth map acquisition, foreground object extraction, feature extraction (shape, texture, position), and engaging state judgment. Each module processes specific aspects of the data independently, making the overall complex task manageable and efficient. The processing apparatus systematically analyzes extracted features to determine the engaging state, balancing accuracy with processing complexity.

Inventive Principle:
Principle #1Segmentation

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

Enables real-time, accurate detection of abnormal engaging states, preventing accidents and reducing maintenance costs by promptly identifying and addressing issues like broken teeth and foreign matter entrapment.

Implementation Method 1

utilizing depth sensing sensors and processing apparatuses that extract shape, texture, and position features

Methodology Applied
Scientific EffectDepth sensing: Time of Flight

Implementation Method 2

processing apparatuses that extract shape, texture, and position features

Methodology Applied
Scientific EffectImage processing: Image Processing

Implementation Method 3

detect foreign matter using optical flow methods to determine abnormal conditions

Methodology Applied
Scientific EffectOptical flow:

Data Source

PatentEP3299330B1Detection of state of engagement between step and comb plate of passenger conveyor
Publication Date: 2022.03.09 OTIS ELEVATOR CO
  • EP3299330B1 patent drawingFigure 1~2
  • EP3299330B1 patent drawingFigure 3
  • EP3299330B1 patent drawingFigure 4

AI summary

The present invention relates to the field of passenger conveyor technologies, and provides an engaging state detection system of a passenger conveyor and a detection method thereof. In the engaging state detection system and detection method, a depth sensing sensor (3101, 310n) is used to sense at least an engaging portion between a step (904) and a comb plate (903) of the passenger conveyor (900) to obtain depth maps, and the depth maps are analyzed by a processing apparatus (100) to detect whether an engaging state between the step (904) and the comb plate (903) is a normal state. The detection of the engaging state includes detection on whether comb teeth of the comb plate are broken, whether engaging teeth of the step are broken, and/or whether a foreign matter exists on an engaging line.