Platoon Gap Control via Lead Vehicle Threat Indicators

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Solution Overview

Problem

Existing methods for controlling inter-vehicle gaps in vehicle platoons are imprecise and unpredictable due to the incorporation of probability indications for risk factors, leading to larger following gaps and more frequent dissolving, which degrades the fuel efficiency and safety of platooning and adaptive cruise control.

Innovation Solution

A method that involves obtaining an indicator of a potential collision threat from an autonomous emergency braking system in the lead vehicle and sending it to following vehicles, allowing them to adjust their gaps based on pre-defined control phases, thereby reducing the time to collision and building a safety margin, while also considering deceleration capacity, to mitigate communication delays and varying brake performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If probability indications are incorporated into risk factor assessments, then safety margin is increased, but measurement precision and predictability deteriorate

Engineering Contradiction:
Improvesafety marginVSAvoidrisk factor assessment precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent extracts the probabilistic assessment component from the risk evaluation system and replaces it with deterministic parameters. Instead of using probability indications like 'slight' or 'moderate' risk, the system uses precise measurements of relative position, speed, and time-to-collision to assess risk factors, thereby maintaining safety while improving measurement precision and predictability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter basis for risk assessment from subjective probability indications to objective physical parameters such as relative position, relative speed, and time-to-collision. This parameter transformation enables precise quantification of risk factors, eliminating the imprecision inherent in probabilistic language while maintaining or enhancing safety margins through accurate prediction of collision scenarios

Inventive Principle:
Principle #35Parameter changes

2Reliability

If larger following gaps are maintained to ensure safety, then collision risk decreases, but fuel efficiency and productivity deteriorate

Engineering Contradiction:
Improvecollision safetyVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by having the lead vehicle communicate collision risk information to following vehicles before a collision threat materializes. This advance notification allows following vehicles to maintain smaller, more fuel-efficient gaps while still having sufficient time to react to potential hazards, thereby improving productivity without compromising safety

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through real-time communication of collision risk parameters from the lead vehicle to following vehicles. This feedback loop enables following vehicles to dynamically adjust their following gaps based on actual risk levels rather than maintaining conservative fixed distances, optimizing the balance between safety and fuel efficiency

Inventive Principle:
Principle #23Feedback

3Productivity

If smaller time gaps are used in platooning, then fuel efficiency improves, but response time to collision threats increases

Engineering Contradiction:
Improvefuel efficiencyVSAvoidresponse time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by enabling following vehicles to receive advance notification of collision risks through V2V communication. This allows following vehicles to prepare for potential hazards before they become immediate threats, compensating for the reduced reaction time inherent in smaller following gaps and maintaining safety while improving fuel efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning by having the lead vehicle communicate potential collision threats to following vehicles in advance. This creates a temporal buffer that compensates for the reduced physical distance in smaller platoons, allowing following vehicles to react appropriately without requiring larger safety margins, thus maintaining both fuel efficiency and response capability

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

Data Source

PatentEP3722913B1Method of controlling inter-vehicle gap(s) in a platoon
Publication Date: 2022.03.09 VOLVO TRUCK CORP
  • EP3722913B1 patent drawingFigure 1
  • EP3722913B1 patent drawingFigure 2
  • EP3722913B1 patent drawingFigure 3

AI summary

The invention relates to a method of controlling inter-vehicle gap(s) (24a-c) in a platoon (10) comprising a lead vehicle (12) and one or more following vehicles (14a-c), wherein an indicator (27) of a potential collision threat (26) is identified by an autonomous emergency braking system and the autonomous emergency braking system comprises pre-defined control phases (28a-c), including a first alert phase (28a), a second warning brake phase (28b), and a third full brake phase (28c).