Escape-Path Planning for Automated Vehicle Lane Changes

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Solution Overview

Problem

Automated vehicles may experience jerky motion when unexpected changes in traffic situations cause a sudden abort of lane-change plans due to unforeseen reductions in distance between vehicles, leading to unsmooth responses.

Innovation Solution

An escape-path-planning system that pre-plans a second-route-plan to steer the vehicle back into its original lane if the forecasted distance between vehicles becomes less than a threshold, avoiding sudden computational delays and ensuring a smoother transition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the automated vehicle uses a standard lane-changing system that computes alternative routes only when needed, then the device complexity is reduced, but the response smoothness deteriorates causing jerky motion

Engineering Contradiction:
Improveroute planning system complexityVSAvoidresponse smoothness
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The system pre-computes an alternative route plan before it is actually needed. When the automated vehicle initiates a lane change, the system simultaneously computes both the primary lane-change route and an alternative route back to the original lane, storing it without executing. This preliminary computation ensures that when unexpected situations arise (such as another vehicle cutting in), the alternative route is already ready, enabling smooth transitions without computational delays or jerky motions.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the automated vehicle aborts a lane-change plan suddenly when distance threshold is violated, then the safety is improved, but the response smoothness deteriorates causing jerky motion

Engineering Contradiction:
Improvecollision avoidanceVSAvoidmotion smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system prepares an alternative route plan in advance that steers the vehicle back to the original lane. When the distance threshold violation occurs, instead of suddenly aborting the lane change, the system smoothly transitions to the pre-computed alternative route, maintaining motion smoothness while ensuring safety.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the automated vehicle computes alternative route on-demand when distance becomes critical, then the processing time is reduced, but the response time increases causing delays

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidresponse delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system computes the alternative route plan in parallel with the primary lane-change route, before the distance threshold violation occurs. This preliminary computation eliminates the need for time-critical on-demand calculations, ensuring that when safety concerns arise, the alternative route is already ready for immediate execution without delays.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3243718B1Escape-path-planning system for an automated vehicle
Publication Date: 2020.09.23 MOTIONAL AD LLC
  • EP3243718B1 patent drawingFigure 1
  • EP3243718B1 patent drawingFigure 2
  • EP3243718B1 patent drawingFigure 3

AI summary

An escape-path-planning system (10) to operate an automated vehicle includes an object-detector (14) and a controller (32). The object-detector (14) is suitable for use on a host-vehicle (12). The object-detector (14) is used to detect an other-vehicle (16) in an adjacent-lane (18) next to a present-lane (20) traveled by the host-vehicle (12). The controller (32) is in communication with the object-detector (14). The controller (32) is configured to, in response to a lane-change-request (34), determine a first-route-plan (40) that steers the host-vehicle (12) from the present-lane (20) to the adjacent-lane (18), determine a second-route-plan (50) that steers the host-vehicle (12) into the present-lane (20), initiate the first-route-plan (40) when a forecasted-distance (24) between the other-vehicle (16) and the host-vehicle (12) is greater than a distance-threshold (46), and cancel the first-route-plan (40) and select the second-route-plan (50) when the forecasted-distance (24) between the other-vehicle (16) and the host-vehicle (12) becomes less than the distance-threshold (46) after the first-route-plan (40) is initiated. The second-route-plan (50) is a pre-planned escape-path that is instantly available if needed that provides a smoother travel-experience for an occupant of the host-vehicle (12).