Vehicle Speed Control Across High-Definition Map Coverage Gaps

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Solution Overview

Problem

In regions where high-definition map information is unavailable, vehicles cannot accurately acquire specified speed information, leading to inappropriate acceleration or deceleration control based on incomplete or incorrect data.

Innovation Solution

A vehicle control method that switches from high-definition map information to lower precision road map information before leaving the high-definition map-available region, ensuring accurate speed control by predicting the exit point and terminating acceleration/deceleration control based on high-definition map information before exiting the region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-definition map information is used for acceleration/deceleration control, then control accuracy is improved, but the system becomes unable to operate in regions where high-definition map information is not available

Engineering Contradiction:
Improvespeed information accuracyVSAvoidregion coverage
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between high-definition map information and general road map information based on the vehicle's current location. When high-definition map information is available, it is used for accurate speed control; when unavailable, the system transitions to general road map information, enabling continuous operation across different regions while maintaining adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of map information precision based on location. It uses high-precision high-definition map information in covered regions and switches to lower-precision general road map information in uncovered regions, allowing the system to adapt to different data quality levels while maintaining functionality.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the system switches from high-definition map information to road map information, then region coverage is improved, but control accuracy deteriorates

Engineering Contradiction:
Improveregion coverageVSAvoidspeed information accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary switching to general road map information before the vehicle completely leaves the high-definition map coverage area. This advance preparation ensures continuous availability of speed information without interruption or loss of control accuracy, even during the transition zone where high-definition map data becomes unavailable.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system cushions the transition between high-definition and general road map information by preparing the switch in advance. This prevents sudden loss of control capability and ensures smooth continuity of acceleration/deceleration control throughout the transition region.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Duration of action of stationary object

If acceleration/deceleration control continues after leaving high-definition map region, then continuous control is maintained, but inappropriate control based on incorrect speed information occurs

Engineering Contradiction:
Improvecontrol continuityVSAvoidcontrol accuracy
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The system continuously monitors the vehicle's location relative to high-definition map coverage and provides feedback to determine when to switch map sources. This feedback mechanism ensures that the system transitions to general road map information at the appropriate moment, maintaining control continuity while preventing use of outdated or incorrect high-definition map data.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4432262B1Vehicle control method and vehicle control device
Publication Date: 2026.02.18 NISSAN MOTOR CO LTD
  • EP4432262B1 patent drawingFigure 1
  • EP4432262B1 patent drawingFigure 2~3B
  • EP4432262B1 patent drawingFigure 4A~4B

AI summary

The controller 20: determines whether or not a current position of an own vehicle (1) is within a high-definition map-available region (Rav) in which high-definition map information (13H) is available; when determining that the current position of the own vehicle is within the high-definition map-available region (Rav), performs acceleration/deceleration control to control acceleration or deceleration of the own vehicle, based on specified speed information acquired by recognizing a speed sign in a captured image or specified speed information acquired from the high-definition map information (13H) based on the current position of the own vehicle and also notifying a driver of the specified speed information; and when the own vehicle is predicted to leave the high-definition map-available region (Rav) to the outside, terminates the acceleration/deceleration control based on the specified speed information and also acquires specified speed information from road map information (13N), the road map information having lower precision than the high-definition map information (13H), based on the current position of the own vehicle and notifies the driver of the acquired specified speed information, at a point (Pc) before a point (Po) at which the own vehicle leaves the high-definition map-available region (Rav) to the outside.