Safe Return Range Navigation Under Fuel And Energy Constraints

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Solution Overview

Problem

Existing navigation systems fail to efficiently display both the currently reachable area and the safe return range to a destination given a fuel or energy constraint, due to the computationally expensive nature of calculating both ranges, especially on mobile devices with limited processing power.

Innovation Solution

A method using one-to-many route planning algorithms to determine a 'safe return range' by exploring segments of an electronic map from a current location, considering a parameter like fuel or energy level, and calculating boundaries for both the currently reachable area and the area from which a predetermined destination can be reached, allowing simultaneous display of both ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If both currently reachable area and safe return range are calculated using traditional methods, then complete navigation information is provided to user, but computational burden exceeds mobile device processing capacity

Engineering Contradiction:
Improvenavigation information completenessVSAvoidcomputational burden
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent pre-calculates and stores reachable areas for multiple destination points before navigation begins. During actual navigation, the system only needs to retrieve and compare these pre-computed areas with the currently reachable area, avoiding real-time calculation of safe return range and significantly reducing computational burden on mobile devices

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent divides the navigation problem into two independent parts: (1) calculating the currently reachable area from the starting point, and (2) retrieving pre-computed reachable areas for destination points. This segmentation allows each part to be processed separately and efficiently, with the second part requiring minimal computation during navigation

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If safe return range calculation is performed in real-time, then accurate travel limits are provided, but processing time and energy consumption increase significantly

Engineering Contradiction:
Improvetravel limit accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs the computationally intensive safe return range calculation in advance and stores the results. During navigation, it only retrieves pre-computed data and compares it with current position, providing accurate travel limits instantaneously without real-time computation delays

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates and stores copies of reachable area data for multiple destination points before navigation begins. During navigation, the system copies and compares these pre-existing data structures rather than recalculating them, maintaining accuracy while minimizing processing time

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3865821B1Methods and systems for determining safe return range
Publication Date: 2025.10.22 TOMTOM NAVIGATION BV
  • EP3865821B1 patent drawingFigure 1
  • EP3865821B1 patent drawingFigure 2
  • EP3865821B1 patent drawingFigure 3

AI summary

A method is disclosed for determining and displaying an area comprising a plurality of locations that can be reached by a person or vehicle from a departure node or current position while still reaching a destination node or home location given the initial value at the departure node or current position of a parameter that constrains the distance travelable by the person or vehicle. The method may be implemented on a mobile device such as a portable navigation device and/or on a server or computer, or may be provided as a computer program product.