Driving Support Device Lateral Velocity Threshold

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Solution Overview

Problem

Conventional driving support devices struggle to distinguish between lane changes and road curvature, leading to vague activation of collision avoidance systems, which can cause unnecessary alarms and discomfort for drivers.

Innovation Solution

A driving support device that uses lateral relative time-dependent change detection to determine the necessity of collision avoidance support, with a steering time and activation threshold to restrain support activation when the time-to-collision is sufficient for steering, and a braking time to assess collision difficulty, thereby differentiating lane changes from road curvature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the driving support device activates collision avoidance support based on time-to-collision threshold, then collision avoidance capability is improved, but unnecessary activation occurs on curved roads causing driver discomfort

Engineering Contradiction:
Improvecollision avoidance capabilityVSAvoiddriver discomfort
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the time-to-collision threshold based on detected lateral relative movement. When lateral movement exceeding the threshold is detected (indicating lane change), the system extends the threshold time from the basic threshold to threshold + Δt, allowing the system to adapt its sensitivity to different driving scenarios and reduce false alarms on curved roads

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of time-to-collision threshold dynamically based on lateral relative velocity detection. By monitoring lateral movement and adjusting the threshold parameter accordingly, the system distinguishes between legitimate lane changes and potential collisions, thereby reducing unnecessary activations while maintaining collision avoidance capability

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the driving support device uses fixed time-to-collision threshold, then system complexity is reduced, but inability to distinguish lane changes from road curvature causes vague activation management

Engineering Contradiction:
Improvesystem complexityVSAvoidactivation determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system segments the collision assessment into two independent evaluation dimensions: longitudinal time-to-collision assessment and lateral relative movement assessment. This segmentation allows the system to independently evaluate lane change likelihood through lateral movement detection while maintaining the original time-to-collision logic, improving activation determination accuracy without significantly increasing overall system complexity

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2913811B1Driving assistance device and driving assistance method
Publication Date: 2019.05.22 TOYOTA JIDOSHA KK
  • EP2913811B1 patent drawingFigure 1
  • EP2913811B1 patent drawingFigure 2~4
  • EP2913811B1 patent drawingFigure 5~7

AI summary

A driving support device which more appropriately manages the necessity of a driving support related to collision avoidance and which effectively restrains unnecessary activation of the driving support is disclosed. The driving support device performs a collision avoidance support on a vehicle (10) relative to a leading vehicle (60) present in a travelling direction of the vehicle (10), based on a time-to-collision Ta as a time that the vehicle (10) takes to collide with the leading vehicle (60). A lateral change amount calculation portion (23) detects a relative lateral velocity Vy, which is a relative time-dependent change amount between the vehicle (10) and the leading vehicle (60). A storage portion (40) stores therein a steering time T1, which is a time required for the vehicle (10) to avoid the leading vehicle (60) by steering. The storage portion (40) stores therein an activation threshold TH1, which is a threshold to determine activation of the driving support based on the relative lateral velocity Vy. When a relative lateral velocity Vy at a time when the time-to-collision Ta is the steering time T1 or more is the activation threshold TH1 or more, a support management portion (50) restrains the activation of the driving support.