Optical Door Sensor Testing for Elevator Reliability

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Solution Overview

Problem

Optical door sensors in elevator installations often malfunction due to environmental factors like dust and electronic noise, leading to incorrect obstacle detection and temporary shutdown of elevator systems, requiring costly and time-consuming maintenance.

Innovation Solution

A method to test the operating margin of optical door sensors by simulating deterioration conditions, determining if the sensor continues to function normally, and generating alerts for necessary corrective actions, allowing for proactive maintenance and switching to a contingency mode to maintain system operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the optical door sensor is used in a dirty or dusty environment, then the sensor can detect obstacles, but material builds up on the sensor causing incorrect detection and system shutdown

Engineering Contradiction:

Improvesensor detection accuracyVSAvoidmaterial build-up on sensor

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary testing by simulating deterioration conditions (offset states) before actual failure occurs. The test module proactively applies offset amounts to sensor parameters and conducts signal tests to detect degradation early, allowing maintenance to be scheduled before material build-up causes incorrect obstacle detection and system shutdown.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If manual cleaning or corrective action is taken to restore sensor function, then the sensor can resume normal operation, but the process is lengthy and expensive

Engineering Contradiction:

Improvesensor operation statusVSAvoidmaintenance time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The optical door sensor system performs self-diagnosis through automated testing. The test module continuously monitors sensor health by simulating deterioration conditions and evaluating signal test results, enabling the system to detect and report its own degradation without requiring manual intervention or external inspection, thereby reducing maintenance time and costs.

Inventive Principle:

Principle #25Self-service

3Productivity

If the sensor operates in adverse conditions, then the elevator can maintain functionality, but the sensor may fail to detect light signals correctly

Engineering Contradiction:

Improveelevator operation continuityVSAvoidsensor signal detection

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts its operation based on sensor health status. When testing reveals degradation (negative signal test results in offset states), the system can switch to contingency modes that maintain elevator functionality while accounting for reduced sensor reliability. This dynamic adaptation allows continuous operation while managing the risk of incorrect detection in adverse conditions.

Inventive Principle:

Principle #15Dynamics

4Measurement precision

If the optical door sensor is highly sensitive, then it can detect light signals accurately, but it becomes more susceptible to electronic noise

Engineering Contradiction:

Improvelight signal detection accuracyVSAvoidelectronic noise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The testing method applies partial deterioration through controlled offset amounts rather than simulating complete failure conditions. By testing with moderate offset states (e.g., 10-20% parameter changes) rather than extreme conditions, the system can detect susceptibility to electronic noise and other harmful factors without completely disabling the sensor's ability to detect light signals, thus balancing detection accuracy with noise susceptibility assessment.

Inventive Principle:

Principle #16Partial or excessive action

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 method enables early detection of sensor degradation, prevents system shutdowns, and ensures safe operation by adjusting door-closing speeds and energies, maintaining elevator functionality in adverse conditions.

Implementation Method 1

emitter for emitting a light signal and a receiver for detecting the light signal

Methodology Applied

Scientific EffectLight emission and detection: Light

Data Source

PatentUS10087049B2Method of testing an optical sensor

Publication Date: 2018.10.02 ENSOTA

AI summary

There is disclosed a method of testing an optical door sensor 100 having an emitter 102 for emitting a light signal 104 and a receiver 106 for detecting the light signal 104, the optical door sensor 100 having at least one sensor operating parameter and further having a baseline state in which the receiver 102 can detect a light signal from the emitter 106. The method comprises setting the optical door sensor in an offset state 204, 304, in which a sensor operating parameter is offset from a baseline setting by an offset amount, the baseline setting corresponding to the baseline state of the optical door sensor; conducting a signal test 206 with the optical door sensor in the offset state; and generating an alert 216 when the signal test result is negative for the offset state and the offset amount is less than or equal to a limit margin. The signal test comprises: emitting a light signal from the emitter 208 and determining whether the light signal is detected by the receiver 210. The signal test has a positive result if the light signal is detected by the receiver and a negative result if the light signal is not detected by the receiver.