Adaptive Cruise Control Time Gap Adjustment via Road Slope Anticipation

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Solution Overview

Problem

Adaptive cruise control (ACC) systems face inefficiencies in maintaining a safe distance on hilly terrain, leading to unnecessary braking and acceleration, which increases fuel consumption and brake wear, especially in heavy vehicles, due to the reliance on local slope measurements rather than anticipating upcoming road slopes.

Innovation Solution

The method adjusts the variable time gap based on the road slope ahead of the vehicle, using geographical position and driving direction data to anticipate changes in terrain, thereby optimizing speed adjustments to maintain a safe distance while minimizing energy expenditure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ACC system adjusts the time gap based on the current road slope measured by a slope sensor, then the system responds to immediate terrain changes, but the vehicle unnecessarily brakes and accelerates when approaching slopes, increasing fuel consumption and brake wear

Engineering Contradiction:

Improvesafe distance maintenanceVSAvoidfuel consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system retrieves road slope information from a database using GPS coordinates to anticipate upcoming slopes before the vehicle reaches them. This preliminary action allows the ACC to adjust the time gap in advance, avoiding unnecessary braking and acceleration cycles, thereby reducing fuel consumption while maintaining safe distance

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the vehicle's position via GPS, compares current location with stored road profile data, and dynamically adjusts the time gap based on anticipated slope changes. This feedback mechanism enables proactive speed adjustments rather than reactive responses, optimizing energy efficiency

Inventive Principle:

Principle #23Feedback

2Device complexity

If the ACC system uses only on-board sensor information for distance control, then the system remains simple in structure, but it cannot anticipate upcoming terrain changes, leading to increased brake wear and energy waste

Engineering Contradiction:

Improvesystem structureVSAvoidbrake replacement frequency

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

The system introduces a road database as an intermediary between the vehicle's on-board sensors and the ACC control unit. This database stores pre-collected road profile information that the system queries using GPS data, enabling anticipation of terrain changes without adding complex physical sensors to the vehicle

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the need for complex mechanical slope sensing and continuous physical measurement systems with an information-based approach using GPS coordinates and digital road profile databases, thereby reducing mechanical complexity while improving predictive capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If the ACC system maintains a fixed time gap regardless of terrain, then the control logic remains simple, but heavy vehicles experience increased fuel consumption and brake wear on hilly terrain

Engineering Contradiction:

Improvecontrol logicVSAvoidenergy waste

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The system retrieves anticipated road slope information from a database using current GPS coordinates before the vehicle encounters the slope. This allows the ACC to proactively adjust the time gap for upcoming terrain changes, enabling heavy vehicles to optimize energy consumption without requiring complex real-time slope sensing

Inventive Principle:

Principle #10Preliminary action

4Reliability

If the ACC system adjusts the time gap based on current slope measurements, then the system adapts to immediate terrain conditions, but it reacts too late to prevent unnecessary braking and acceleration cycles

Engineering Contradiction:

Improveterrain adaptationVSAvoidresponse delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

By querying the road database with current GPS coordinates to retrieve slope information for upcoming terrain changes, the system performs preliminary adaptation before the vehicle reaches the slope. This eliminates response delay and allows smooth, energy-efficient speed adjustments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously feeds back the vehicle's GPS position to the control unit, which compares it with the stored road profile to determine upcoming terrain conditions. This real-time feedback enables the ACC to adjust the time gap proactively, maintaining terrain adaptation without delay

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP3250429B1Method and control unit for adjusting a time gap

Publication Date: 2022.06.15 SCANIA CV AB

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Figure 3A

AI summary

Method (400) and control unit (310) in a vehicle (100) having an ACC, system (500), for adjusting a variable time gap (t) to be kept to a preceding vehicle (110), based on a road slope (α). The method (400) comprises determining (401) geographical position of the vehicle (100); determining (402) driving direction (105) of the vehicle (100); determining (403) the road slope (α) of the road (120) in front of the vehicle (100) in the determined (402) driving direction (105); and adjusting (408) the variable time gap (t) based on the deter- mined (403) road slope (α) of the road (120) in front of the vehicle (100) by: increasing the variable time gap (t) when the road slope (α) is negative, indicating downhill; or decreasing the variable time gap (t) when the road slope (α) is positive, indicating uphill.