Multilateration Calibration via Two-Way Ranging

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Solution Overview

Problem

Existing multilateration methods face challenges in accurately locating objects in multi-dimensional spaces using one-dimensional distance estimates between pairs of objects, particularly when the number of anchor points increases or when anchor points need to be relocated, as they require precise physical measurements which are difficult to obtain.

Innovation Solution

The method employs two-way ranging for calibration to determine the exact position of anchor points using rank deficient matrix approximation and recursive triangular reconstruction techniques, allowing for object localization in multi-dimensional spaces with one-dimensional distance measurements without direction information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If traditional multilateration methods are used with increasing anchor points, then localization coverage is improved, but measurement precision deteriorates due to difficulty in obtaining precise physical measurements

Engineering Contradiction:

Improvelocalization coverageVSAvoiddistance measurement precision

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent replaces traditional mechanical measurement systems (physical tape measures, laser rangefinders) with an electronic two-way ranging system. The system uses signal transmission time between anchor points and target objects to calculate distances, eliminating the need for physical measurement tools. This substitution maintains measurement precision while enabling scalable deployment of numerous anchor points for improved localization coverage.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system enables anchor points to self-calibrate by performing mutual two-way ranging with each other. Each anchor point automatically determines its position relative to other anchor points through signal exchange, eliminating the need for manual physical measurement and positioning. This self-service mechanism maintains precision while allowing flexible deployment of anchor points to expand coverage area.

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If anchor points are relocated to improve coverage, then adaptability is improved, but measurement precision deteriorates due to loss of pre-calibrated positions

Engineering Contradiction:

Improveanchor point relocation capabilityVSAvoidposition accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system transitions from static pre-calibrated anchor positions to dynamic self-calibrating positions. When anchor points are relocated, they automatically perform two-way ranging with neighboring anchor points to recalculate their positions. This dynamic adaptation maintains position accuracy while enabling flexible relocation of anchor points to improve coverage or respond to changing environmental requirements.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs preliminary calibration by having anchor points establish mutual distance relationships through two-way ranging before actual object localization begins. This preliminary action creates a reference framework that remains valid even when individual anchor points are relocated, as long as the overall geometry is recalibrated. This enables adaptability while maintaining measurement precision through systematic recalibration.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If two-way ranging is implemented for calibration, then device complexity increases, but manufacturing precision is improved by eliminating physical measurements

Engineering Contradiction:

Improveposition calibration accuracyVSAvoidcalibration system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses the same communication infrastructure and signal processing capabilities for both normal operation (object localization) and calibration (anchor point positioning). The two-way ranging mechanism serves dual purposes: it calibrates anchor positions and simultaneously provides the measurement basis for locating target objects. This multi-functionality improves manufacturing precision without proportionally increasing device complexity, as the same hardware performs multiple functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Ease of operation

If one-dimensional distance estimates are used without direction information, then ease of operation is improved, but measurement precision deteriorates

Engineering Contradiction:

Improvelocalization system simplicityVSAvoidposition estimation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system compensates for the lack of directional information by utilizing the temporal dimension. Two-way ranging measures the time for signals to travel between anchor points and target objects, converting spatial direction information into temporal measurements. This dimensionality change allows the system to maintain position estimation accuracy using only one-dimensional distance estimates, while preserving ease of operation by avoiding complex directional sensing requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11441890B2Linear-grammetry and calibration by simultaneous multilateration using only edge distance estimates through two-way ranging

Publication Date: 2022.09.13 NEC CORP

AI summary

Aspects of the present disclosure describe systems, methods and structures that perform linear-grammetry and calibration by simultaneous multilateration using only edge distance estimates via two-way ranging.