Elevator Radar Positioning With Cascading Shaft Reflectors

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Solution Overview

Problem

Existing elevator positioning systems face challenges in accurately determining the position of an elevator car within a shaft due to signal strength attenuation of radar reflections over long distances, constrained by regulations and limited space, leading to unreliable distance measurements.

Innovation Solution

A radar-based elevator positioning system using a plurality of radar reflectors positioned at different heights within the elevator shaft, with a controller selecting a target reflector based on empirical height measurements and radar-based distance measurements to determine the elevator car's position, minimizing signal attenuation and ensuring accurate positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar-based distance measurement is used to determine elevator car position, then positioning capability is provided, but signal strength attenuation over long distances causes unreliable measurements

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The elevator shaft is segmented into multiple zones with radar reflectors positioned at different heights. Instead of relying on a single distant reflector, the system divides the measurement task into multiple segments, each handled by a nearby reflector. This segmentation ensures that at least one reflector remains within optimal signal range regardless of the car's position, resolving the contradiction between providing coverage and maintaining signal strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Radar reflectors act as intermediaries between the radar transceiver and the distant shaft environment. These reflectors are strategically positioned to serve as intermediate measurement points, allowing the system to determine car position indirectly through multiple reference points rather than directly measuring distant positions, thereby maintaining measurement reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple radar reflectors are positioned along the elevator shaft, then positioning accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the shaft into zones with distributed reflectors, improving measurement precision through multiple reference points. The controller implements a selection algorithm that chooses the most suitable reflector based on current car position, managing the complexity by processing only relevant data from active zones rather than all reflectors simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary actions by pre-establishing the positions and characteristics of multiple radar reflectors throughout the shaft before operation. This preliminary configuration allows the controller to efficiently select appropriate reflectors based on predetermined height segments, reducing real-time computational complexity while maintaining high positioning accuracy.

Inventive Principle:
Principle #10Preliminary action

3Area of stationary object

If radar reflectors are positioned far apart to cover the entire shaft, then coverage is improved, but signal attenuation increases

Engineering Contradiction:
Improvecoverage areaVSAvoidsignal attenuation
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The shaft coverage area is segmented into multiple zones, each with its own radar reflector. This segmentation allows the system to provide full shaft coverage while keeping individual reflector spacing within optimal signal ranges. The controller dynamically selects which zone's reflector to use based on the car's current position, ensuring consistent signal strength across the entire coverage area.

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

The system achieves precise elevator car positioning with an error of less than 10 millimeters, satisfying industry standards by reliably selecting a target reflector and reducing noise and interference, thereby ensuring accurate and consistent elevator car positioning.

Implementation Method 1

a radar-based distance measurement system used for detecting and measuring reflected radar signals from a plurality of radar reflectors

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

measuring reflected radar signals from a plurality of radar reflectors

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4174006B1Elevator positioning system with cascading reflector arrangement
Publication Date: 2025.09.24 HONEYWELL INTERNATIONAL INC
  • EP4174006B1 patent drawingFigure 1
  • EP4174006B1 patent drawingFigure 2
  • EP4174006B1 patent drawingFigure 3

AI summary

Various embodiments are directed to determining an elevator car position within an elevator shaft using radar-based distance measurements and a plurality of radar reflectors positioned along the elevator shaft. In one aspect, an example method is provided. The method includes associating a height segment of the elevator shaft with each of the plurality of radar reflectors. The method further includes selecting a target reflector from the plurality of radar reflectors based at least in part on an initial height of the elevator car being within a height segment associated with the target reflector. The method further includes determining an inferred position of the elevator car within the elevator shaft based at least in part on determining a radar-based distance measurement to the target reflector. The radar reflectors may be positioned such that at least one radar reflector is optimally detectable by a dynamically-positioned radar transceiver of the elevator car.