Navigation Device Mode Switching for Location Accuracy

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Solution Overview

Problem

Car navigation devices face errors in displaying the current location when used as personal navigation devices (PNDs), as they may incorrectly show locations on roads when the user is not actually on a vehicle path, especially when used on foot, due to GPS inaccuracies and map matching issues.

Innovation Solution

The navigation device switches between normal and pedestrian modes, using map matching to correct location display on roads in normal mode and stopping map matching in pedestrian mode to prevent errors, with distinct marks and display adjustments for intuitive location representation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If map matching is used to correct current location in normal mode, then location accuracy on roads is improved, but erroneous location display occurs when used as PND for pedestrian navigation

Engineering Contradiction:
Improvecurrent location accuracyVSAvoidlocation display reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies dynamics by making the map matching function adjustable rather than fixed. The control unit dynamically switches map matching on or off based on the detected use mode (vehicle or pedestrian), allowing the system to adapt its location correction behavior to the appropriate context and eliminate erroneous displays

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the navigation device is designed for in-vehicle use with map matching, then natural display on roads is improved, but it causes erroneous display when used as portable device

Engineering Contradiction:
Improveintuitive location displayVSAvoidmulti-use adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements universality by enabling the navigation device to function effectively in both vehicle and pedestrian modes. The control unit detects the use mode and automatically adjusts the map matching application, allowing the single device to provide appropriate location display for different usage scenarios without requiring separate devices

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

Solution Approach 2:

The system dynamically adapts its behavior based on detected use mode. When pedestrian mode is detected, map matching is suspended to prevent erroneous location correction, while vehicle mode enables map matching for natural road-aligned display, making the device versatile across different use cases

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If GPS detection is used alone, then portability and versatility are improved, but location accuracy and natural display on roads deteriorate

Engineering Contradiction:
Improveportable use capabilityVSAvoidcurrent location accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by conditionally applying map matching based on use mode detection. In vehicle mode, GPS detection is enhanced with map matching to improve accuracy and natural road display. In pedestrian mode, the system relies on GPS alone to avoid erroneous corrections, thus maintaining versatility while optimizing accuracy for each context

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2161543B1Navigation device and associated display method
Publication Date: 2020.04.22 SONY GROUP CORP
  • EP2161543B1 patent drawingFigure 1A~1B
  • EP2161543B1 patent drawingFigure 2
  • EP2161543B1 patent drawingFigure 3

AI summary

A navigation device is provided with a current location detection unit for detecting a current location, a current location correction unit for correcting the current location detected by the current location detection unit using map matching and a display unit for displaying a map. The navigation device switches an operation mode between a normal mode, which is an operation mode based on in-vehicle use, and a pedestrian mode, which is an operation mode based on use when moving on foot, displays the map of the current location by the display unit by arranging a mark indicating the current location based on the current location corrected by the current location correction unit in the normal mode, and displays the map of the current location by the display unit by arranging the mark indicating the current location based on the current location detected by the current location detection unit in the pedestrian mode.