Relative Lane Determination Using Trajectory-Map Matching

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Solution Overview

Problem

Existing driving assistance systems fail to accurately determine relative positions of moving objects when the accuracy of position information of either the moving objects or map information is unknown.

Innovation Solution

A relative position determining apparatus that includes a first trajectory information obtaining unit, a second trajectory information obtaining unit, a map information obtaining unit, a matching determining unit, and a relative lane determining unit, which determine whether the trajectory information matches lane shape information and calculate relative lanes between moving objects, enabling accurate position determination even when accuracy is unknown.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If relative positions are determined by matching moving objects to map information based on position information, then driving assistance can be provided, but relative position information is mistakenly determined when there is an error in position information or map information

Engineering Contradiction:

Improveaccuracy of relative position determinationVSAvoidaccuracy of position information

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces trajectory information as an intermediary element between position information and map information. Instead of directly matching position information with map information, the system matches trajectory information (which reflects actual moving object paths) with lane shape information from maps. This intermediary approach allows the system to identify and correct errors in either position information or map information by comparing against the actual trajectory patterns observed from moving objects.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent performs preliminary matching of trajectory information with lane shape information before determining relative positions. By pre-establishing the relationship between observed trajectories and map lane shapes, the system creates a reference framework that can be used to validate and correct position information subsequent to the matching process, thereby improving the reliability of relative position determination.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If driving assistance is restricted in the presence of an error in position information, then accuracy is maintained, but driving assistance cannot be provided when accuracy is unknown

Engineering Contradiction:

Improveaccuracy of position informationVSAvoidapplicability of driving assistance

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter used for determining driving assistance applicability from binary accuracy status to a continuous matching degree between trajectory information and lane shape information. By evaluating the degree of match rather than requiring definitive accuracy confirmation, the system can adaptively provide driving assistance across a broader range of conditions, including cases where accuracy is unknown but the trajectory-map matching degree is sufficiently high.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If map information is corrected using time series of position information, then map information accuracy is improved, but the system requires clear accuracy status to function

Engineering Contradiction:

Improveaccuracy of map informationVSAvoidaccuracy status confirmation

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent inverts the traditional correction approach by using trajectory information (derived from actual moving object motion) to validate and correct map information, rather than using position information correction methods that require known accuracy status. The matching process between trajectories and lane shapes inherently provides the validation mechanism, eliminating the need for separate accuracy status confirmation.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS11915494B2Relative position determining apparatus, relative position determining method, and non-transitory computer readable recording medium

Publication Date: 2024.02.27 MITSUBISHI ELECTRIC CORP

AI summary

A relative position determining apparatus according to the present invention includes: a first trajectory information obtaining unit obtaining first trajectory information that is a set of first trajectory points indicating positions that a first moving object has passed; a second trajectory information obtaining unit obtaining second trajectory information that is a set of second trajectory points indicating positions that a second moving object has passed; a map information obtaining unit obtaining map information including lane shape information indicating a shape of each lane; a matching determining unit determining whether each of the first trajectory information and the second trajectory information matches the lane shape information; and a relative lane determining unit determining relative lanes of the first moving object and the second moving object, based on a result of the determination by the matching determining unit.