Land Vehicle Navigation Using Road Geometry Constraints

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Solution Overview

Problem

Existing navigation systems for land vehicles face challenges in achieving precise navigation data without relying on GNSS or odometer systems, due to issues like jamming, signal reception difficulties, and operational constraints such as periodic stops for zero-speed hybridization, which can impose operational limitations.

Innovation Solution

A method that integrates inertial data with road geometry and orientation parameters to estimate vehicle navigation data, correcting errors by solving equations assuming bounded displacements within the road's constraints, using a Kalman filter for error estimation and correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If GNSS radio navigation system is used to correct inertial navigation data, then positioning accuracy is improved, but vulnerability to jamming attacks increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidjamming attacks
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces road geometry parameters as an intermediary reference framework. Instead of relying directly on GNSS signals that can be jammed, the system uses the geometric constraints of the road (width, orientation, curvature) as a mediator to validate and correct inertial navigation data, thereby achieving positioning accuracy without vulnerability to GNSS jamming attacks

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If odometer data is used to correct navigation data, then positioning accuracy is improved, but system integration complexity increases

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

Solution Approach 1:

The patent extracts and utilizes only the essential geometric parameters of the road (width, orientation, curvature) from the complex environment, rather than integrating complete odometer systems. This selective extraction provides sufficient correction data while significantly reducing system integration complexity and avoiding the challenges of adapting comprehensive odometer systems to various vehicle types

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If zero-velocity hybridization is implemented, then positioning accuracy is improved, but operational flexibility decreases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidoperational flexibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent enables continuous navigation data correction by continuously utilizing road geometry parameters throughout the vehicle's movement. Instead of requiring periodic stops for zero-velocity updates, the system continuously references the road's geometric constraints to correct inertial measurement drift, maintaining both positioning accuracy and operational flexibility during continuous motion

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If complex kinematic model is used to estimate navigation data, then positioning accuracy is improved, but model complexity increases

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

Solution Approach 1:

The patent applies local quality by utilizing specific geometric parameters of the road (width, orientation, curvature) that are directly relevant to the vehicle's motion constraints. Rather than employing a comprehensive complex kinematic model of the entire vehicle, the system focuses on the local geometric constraints imposed by the road, providing accurate positioning with simplified modeling

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3724605B1Method for estimating navigation data of a land vehicle using road geometry and orientation parameters
Publication Date: 2021.10.27 SAFRAN ELECTRONICS & DEFENSE (FR)
  • EP3724605B1 patent drawingFigure 1a~1c
  • EP3724605B1 patent drawingFigure 2~3
  • EP3724605B1 patent drawing

AI summary

The invention concerns a method for estimating navigation date of a land vehicle, comprising steps of: ▪ receiving inertial data (100) acquired by an inertial sensor, ▪ receiving geometry and orientation parameters of a travelled road, ▪ integrating (106) the data on the basis of the parameters in order to produce navigation data comprising a movement of the vehicle relative to the road measured in a direction (Zr, Yr), the vehicle only being able to move in the direction within a bounded interval without leaving the road, ▪ estimating (108) an error affecting the navigation data by solving equations assuming that a difference between the calculated movement and a reference movement constitutes an error in the movement of the vehicle parallel to the direction, the reference movement having a value less than or equal to the length of the interval, ▪ correcting (110) the produced navigation data from the estimated error.