DENM Collision Warning for Occluded Vehicle Pre-Crash Detection

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Solution Overview

Problem

Existing Cooperative Intelligent Transport Systems (C-ITS) are limited in their ability to effectively communicate collision risks between vehicles that are not in sight of each other, particularly in situations where occlusions occur, such as at intersections.

Innovation Solution

A method and system for generating a Decentralized Environmental Notification Message (DENM) that includes additional containers with object information, allowing road-side units (RSUs) to report collision risks to vehicles that may not be in sight of each other, leveraging their broader view and processing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vehicles use direct V2V communication for collision warning, then response time is reduced, but coverage is limited to vehicles in sight of each other

Engineering Contradiction:
Improvecollision warning effectivenessVSAvoidcoverage of collision detection
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces RSUs as intermediary entities that receive sensor data from vehicles, detect collision risks independently, and send warnings to vehicles that cannot communicate directly. This mediator approach extends coverage to occluded vehicles while maintaining reliable collision detection through the RSU's broader environmental awareness.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If RSUs monitor and detect collision risks for occluded vehicles, then coverage is improved, but system complexity increases

Engineering Contradiction:
Improvecoverage of collision detectionVSAvoidsystem architecture complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments functionality between vehicles and RSUs: vehicles perform local sensing and direct V2V communication, while RSUs perform environmental monitoring and V2I communication. This segmentation allows each component to have specialized, optimized functionality, managing overall system complexity through clear role division.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The DENM message format is designed to be universal, serving both direct V2V collision warnings and indirect V2I warnings from RSUs. This multi-functional message structure handles different communication paths and information sources without requiring separate protocols, reducing system complexity.

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

3Loss of information

If DENM messages include detailed object information from multiple containers, then information completeness is improved, but message size and processing load increase

Engineering Contradiction:
Improveinformation completeness of collision dataVSAvoidmessage data volume
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential collision-related information from the full sensor environment model, placing it in dedicated containers within the DENM message. This selective extraction provides complete collision data while minimizing message size by excluding unrelated environmental information.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The DENM message structure nests multiple containers (basic DENM data, perceived objects, collision risk information) within a hierarchical framework. This nesting organizes information efficiently, allowing receivers to process only relevant containers based on their specific needs, reducing overall processing load.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4163895B1Pre-crash DENM message within an intelligent transport system
Publication Date: 2025.11.12 CANON KK
  • EP4163895B1 patent drawingFigure 1
  • EP4163895B1 patent drawingFigure 2
  • EP4163895B1 patent drawingFigure 3

AI summary

The present invention regards Cooperative Intelligent Transportation Systems, C-ITS. A single DENM, i.e. a warning message announcing a detected event such as an accident/collision or a risk of collision or a pre-crash situation, conveys information about multiple objects involved in the detected situation, in particular about the critical objects involved in the collision. The originating ITS station, ITS-S, quickly builds the DENM because containers describing the objects it perceives are already built in a so-called Local Dynamic Map or Environment Model. On the other side, the receiving ITS-S involved in the detected event obtains more information from the single DENM, compared to known technics (CAMs or CPMs). It can then perform a quicker analysis of the situation and then decide earlier to activate or not anti-collision or pre-crash functions.