Adaptive Cruise Control for Early Turn and Lane-Change Detection

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Solution Overview

Problem

Existing adaptive cruise control systems struggle to balance passenger comfort and safety by frequently causing unnecessary and excessive braking due to late detection of target vehicles changing lanes or turning, especially in bends.

Innovation Solution

A method and device that determine a probability indicator of a target vehicle's turn based on the ratio of longitudinal to lateral speed, adjusting the relevance indicator to control the adaptive cruise control system, thereby optimizing inter-vehicle distance and reducing unnecessary braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the ACC system maintains a fixed inter-vehicle time setting, then the system operation is simple, but the system causes excessive braking and reduces passenger comfort when the target vehicle changes lanes or turns

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidexcessive braking
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the inter-vehicle time setting adjustable rather than fixed. The system dynamically modifies the inter-vehicle time based on detected trajectory changes of the target vehicle, increasing it when a turn or lane change is detected and decreasing it when the target vehicle is stable. This resolves the contradiction by allowing simple operation under normal conditions while adapting to prevent excessive braking during maneuvers.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of inter-vehicle time based on the target vehicle's behavior. By monitoring lateral speed and calculating probability indicators of trajectory changes, the system adjusts the inter-vehicle time parameter upward when turns or lane changes are likely, preventing unnecessary braking. This parameter adaptation resolves the contradiction between simple fixed-time operation and comfortable adaptive operation.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the ACC system uses traditional detection methods, then the detection system is simple, but the system fails to detect target vehicle turns early causing late deselection

Engineering Contradiction:
Improvedetection system complexityVSAvoiddetection delay
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by detecting early signs of trajectory changes before the target vehicle completes its turn or lane change. By monitoring lateral speed and calculating probability indicators in advance, the system identifies impending maneuvers and adjusts inter-vehicle time proactively, enabling early deselection of the target vehicle. This resolves the contradiction by providing advance detection without requiring complex additional sensors.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary calculation layer that processes existing sensor data (lateral speed, longitudinal speed) to generate probability indicators of trajectory changes. This intermediary processing step extracts meaningful information from simple sensor inputs, enabling early turn detection without adding complex detection hardware. The mathematical model acts as an intermediary that transforms basic speed data into predictive information.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the ACC system maintains a constant following distance, then the control logic is simple, but the system cannot adapt to target vehicle maneuvers reducing safety and comfort

Engineering Contradiction:
Improvecontrol logic complexityVSAvoidadaptation to target vehicle behavior
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent makes the following distance dynamic by linking it to the inter-vehicle time parameter that adjusts based on target vehicle behavior. When the probability indicator suggests a turn or lane change, the system increases the following distance, providing adaptive control. This resolves the contradiction by implementing adaptive following distance through dynamic parameter adjustment rather than complex control logic.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4444588B1Method and device for controlling a vehicle's adaptive cruise control system
Publication Date: 2025.09.03 STELLANTIS AUTO SAS
  • EP4444588B1 patent drawingFigure 1~2
  • EP4444588B1 patent drawingFigure 3~4
  • EP4444588B1 patent drawingFigure 5

AI summary

The present invention relates to a method and device for controlling an adaptive cruise control system, referred to as an ACC system, of a first vehicle (10). The ACC system targets a second vehicle (11) travelling in front of the first vehicle (10). The lateral speed and the longitudinal speed of the second vehicle (11) are determined. An indicator of the probability of the second vehicle (11) performing a turn with a given radius of curvature is determined based on the ratio of the longitudinal speed to the lateral speed. A relevance indicator associated with the second vehicle is determined based on the probability indicator. The ACC system of the first vehicle (10) is controlled based on this relevance indicator.