Navigation Device Route Determination Using Pre-calculated Path Trees
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing route planning algorithms, such as Dijkstra and A* methods, are slow when determining routes between regions with changing traffic conditions or different cost functions, as they require recalculating paths from scratch, leading to suboptimal routes and increased processing time.
Innovation Solution
A method that pre-calculates minimum cost paths between regions for multiple cost functions and times, using a tree of shortest paths divided into regions, allowing for quick identification of the lowest cost path based on user-selected criteria, including travel time, and updates routes in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pre-processed tree of shortest paths is stored for a single cost function, then route determination speed is improved, but the system cannot handle different cost functions or changing traffic conditions without recalculating from scratch
Solution Approach 1:
The patent pre-calculates and stores multiple trees of shortest paths corresponding to different cost functions before route determination is needed. When a user selects a cost function, the system retrieves the pre-computed tree matching that cost function, avoiding recalculation. This preliminary action for multiple scenarios resolves the contradiction by maintaining fast retrieval speed while adapting to different cost function requirements.
Solution Approach 2:
The patent changes the parameter of cost function type by pre-computing and storing separate shortest path trees for different cost functions (e.g., time-based, distance-based, toll-based). The system selects the appropriate pre-computed tree based on the user's chosen cost function, enabling versatile adaptation without sacrificing retrieval speed.
2Reliability
If route recalculation is performed from scratch when traffic conditions change, then route optimality is improved, but processing time increases significantly
Solution Approach 1:
The system performs preliminary calculations of shortest paths for multiple cost functions and stores them in advance. When traffic conditions change or a user requests a route, the system retrieves the relevant pre-computed shortest path tree instead of recalculating from scratch, significantly reducing processing time while maintaining route optimality for the selected cost function.
Solution Approach 2:
The patent implements a dynamic system that adapts to changing traffic conditions by selecting the appropriate pre-computed shortest path tree based on current conditions and user preferences. The system dynamically switches between different pre-computed trees corresponding to different cost functions, maintaining optimal routes without full recalculation.
3Adaptability or versatility
If multiple trees of shortest paths for different cost functions are pre-calculated and stored, then adaptability to different cost functions is improved, but memory requirements increase
Solution Approach 1:
The system performs preliminary calculation and storage of shortest path trees for multiple cost functions. By pre-computing these paths and storing them in memory, the system enables fast retrieval and versatile cost function support without requiring recalculation, accepting increased memory volume as a trade-off for improved adaptability and speed.
Solution Approach 2:
The patent addresses memory requirements by organizing stored shortest path data according to different cost function parameters. Multiple trees are pre-calculated and stored, each corresponding to a specific cost function parameter (time, distance, tolls), enabling the system to adapt to different user preferences while managing memory through structured storage.
4Productivity
If pre-processed data is used for route determination, then processing speed is improved, but the system becomes slow when recalculating for different cost functions or changing conditions
Solution Approach 1:
The patent performs preliminary calculation and storage of shortest path trees for multiple cost functions before route determination is needed. This advance preparation enables rapid retrieval when routes are requested, significantly improving productivity while avoiding the time loss associated with recalculation. The system maintains pre-processed data for multiple scenarios to ensure fast response under varying conditions.
Data Source
AI summary
This invention concerns a method of determining a route using map data comprising a plurality of navigable paths, the map data divided into a plurality of regions. The method comprises using at least one processing apparatus to: receive an origin and a destination on the map data and a selection of one of a plurality of cost functions and determine a route from the origin to the destination using the map data and minimum cost data that identifies minimum cost paths between regions of the map data. The minimum cost data identifies more than one minimum cost path between a pair of the regions if different minimum cost paths exist between the pair of regions for different cost functions and determining a route comprises identifying from the minimum cost paths for the pair of regions comprising the origin and destination, the minimum cost path having a lowest cost for the selected cost function.