Vehicle Self-Position Estimation on Curved Paths

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Solution Overview

Problem

Existing self-position estimation technologies, such as those using odometry, experience accuracy deterioration when a vehicle transitions from a straight path to a curved path due to limited environmental information on curved paths.

Innovation Solution

A self-position estimation device and method that utilizes target position data along the shape of a curve, including data around the vehicle and between the current position and the curve start position, to estimate the vehicle's position accurately on curved paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of base stations is increased to improve positioning accuracy, then positioning precision is improved, but device complexity and system cost increase

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

Solution Approach 1:

The patent replaces the mechanical approach of increasing physical base station infrastructure with an electronic/software-based solution. The positioning system uses signal processing algorithms and mathematical calculations to achieve accurate positioning without requiring additional hardware base stations, thereby substituting a mechanical expansion approach with an electronic computation approach.

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

Solution Approach 2:

The positioning system is designed to work with existing base station infrastructure while maintaining compatibility with current network operations. The same base stations serve both traditional communication functions and positioning functions, eliminating the need for dedicated positioning infrastructure and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If positioning calculations are performed in the radio base station to improve positioning accuracy, then positioning precision is improved, but communication system load increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidcommunication system load
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent extracts the computationally intensive positioning calculation functions from the radio base station and relocates them to a dedicated positioning calculation unit. This separation allows the base station to handle only lightweight signal reception and transmission tasks, while the specialized positioning unit processes the complex calculations, thereby reducing the communication system load.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A dedicated positioning calculation unit is introduced as an intermediary component between the base station and the positioning system. This intermediary handles all heavy computational tasks, allowing the base station to maintain its primary communication functions with minimal additional load while still enabling accurate positioning through the intermediary's processing capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3327532B1Self-position estimation device and method for estimating self-position
Publication Date: 2021.01.27 NISSAN MOTOR CO LTD
  • EP3327532B1 patent drawingFigure 1
  • EP3327532B1 patent drawingFigure 2
  • EP3327532B1 patent drawingFigure 3

AI summary

A self-position estimation device includes: a target position detection unit mounted in a vehicle, the target position detection unit being configured to detect a relative position of a target present around the vehicle and the vehicle; a movement amount estimation unit configured to estimate a movement amount of the vehicle; a target position accumulation unit configured to move the detected relative position by the estimated movement amount and to accumulate the moved relative position as target position data; a map information acquisition unit configured to acquire map information including target position information of a target present on a map; a curve start position estimation unit configured to estimate a curve start position of a travel path on which the vehicle travels; and a self-position estimation unit configured to perform comparison in which at least the target position data present around the vehicle and the target position data present between a current position of the vehicle and the estimated curve start position, of the accumulated target position data, is compared with the target position information included in the map information to estimate a self position which is the current position of the vehicle.