Route Search Device for Incomplete Accessibility Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing route search systems fail to provide appropriate navigation for users with specific mobility needs, such as seniors or wheelchair users, due to incomplete accessibility information on all routes in Japan, leading to potential circuitous or unsecured routes.
Innovation Solution
A route search device and method that calculates route appropriateness values by considering passage difficulty and uncertainty for both investigated and uninvestigated links, allowing for the selection of the most suitable route based on transportation means, even when accessibility information is incomplete.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a route search is performed only with links having accessibility information, then the route search reliability is improved, but the route availability deteriorates (no route can be secured or results in circuitous route)
Solution Approach 1:
The patent applies partial action by performing route search using both investigated links (with accessibility information) and uninvestigated links (without accessibility information). The system selectively uses available data where it exists while accepting incomplete data where necessary to maintain route availability, rather than requiring complete information for all links.
Solution Approach 2:
The patent introduces an intermediary mechanism - the passage uncertainty degree calculation unit - that quantifies the reliability of uninvestigated links. This intermediary allows the system to bridge the gap between complete information requirements and incomplete data availability by providing a measured approach to using unverified link data.
2Productivity
If uninvestigated links are included in the route search, then the route availability is improved, but the route search reliability deteriorates (passage uncertainty increases)
Solution Approach 1:
The patent implements feedback by calculating passage uncertainty degrees for routes containing uninvestigated links and using this information to evaluate and compare route appropriateness. The uncertainty calculation provides feedback about the quality of route options, allowing the system to balance availability with reliability considerations.
Solution Approach 2:
The patent changes the parameter of link evaluation from binary (investigated/not investigated) to continuous (passage uncertainty degree). By introducing uncertainty as a quantifiable parameter, the system can differentiate between various levels of confidence in uninvestigated links and make more nuanced route selection decisions.
3Measurement precision
If accessibility information is collected through investigation, then the passage difficulty accuracy is improved, but the information completeness deteriorates (not all routes are covered)
Solution Approach 1:
The patent accepts partial information coverage by allowing route search to proceed with a mix of investigated and uninvestigated links. Rather than requiring complete investigation of all links before enabling route search, the system works with the partial information available while maintaining the option to expand coverage over time.
Data Source
AI summary
It is intended to allow an appropriate route search to be performed even with a geographical NW in which accessibility information includes an uninvestigated link. A route appropriateness value calculation unit 160 calculates, for each of a plurality of routes each connecting a departure point and a destination extracted by a route extraction unit 120 and including links connecting individual spots including the departure point and the destination, a route appropriateness value of the route. The route appropriateness value of the route is calculated on the basis of a cost of the route calculated by a cost calculation unit 140 on the basis of a cost representing a degree of passage difficulty which is determined for each of the links with respect to a transportation means on the basis of accessibility information of the investigated link as well as a degree of passage uncertainty representing a possibility that the route cannot be passed through by the transportation mean which is calculated by a passage uncertainty degree calculation unit 150 on the basis of a length of the uninvestigated link included in the route. A route selection unit 180 selects, from among the plurality of routes, the route on the basis of the route appropriateness value of the route.