Work Vehicle Travel Control Using Operation-Tool Switch Thresholds

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Solution Overview

Problem

Conventional travel control systems for work vehicles switch from autonomous to manual travel based on steering device states, leading to unintended manual travel during autonomous operations when the steering direction changes unintentionally.

Innovation Solution

A travel control method and system that switches from autonomous to manual travel based on a user operation's change amount exceeding a threshold, with the threshold set according to the work vehicle's settings and information, allowing for controlled transitions between autonomous and manual steering modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If switching from autonomous travel to manual travel is triggered by detecting a steering state change of the steering device, then the work vehicle can respond to operator input, but unintended manual travel may occur when the steering direction changes unintentionally

Engineering Contradiction:
Improveresponsiveness to operator inputVSAvoidaccuracy of mode switching
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the parameter used for detecting operator input from simple steering angle detection to detection based on operation amount of the operation tool (e.g., accelerator pedal depression amount, brake pedal depression amount). This parameter change allows the system to distinguish between intentional operator actions and unintentional steering variations, thereby improving the reliability of mode switching while maintaining responsiveness to genuine operator input.

Inventive Principle:
Principle #35Parameter changes

2Speed

If the threshold for switching is set low to detect small steering changes, then operator input is detected quickly, but false triggering increases during autonomous travel

Engineering Contradiction:
Improveswitching response speedVSAvoidfalse triggering rate
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent changes the detection parameter from steering angle to operation amount of the operation tool, and introduces a threshold value for this operation amount. By setting an appropriate threshold for the operation amount (e.g., minimum accelerator depression amount), the system achieves both fast response to genuine operator input and suppression of false triggering during autonomous travel, thus resolving the contradiction between switching speed and reliability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the threshold for switching is set high to prevent false triggering, then reliability improves, but response time to legitimate operator input increases

Engineering Contradiction:
Improvefalse triggering rateVSAvoidmode switching delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses operation amount of the operation tool as the detection parameter with a threshold value. This approach allows the threshold to be set at an appropriate level that filters out false triggers while maintaining quick response to legitimate operator actions. The operation amount parameter naturally provides a good signal-to-noise ratio, enabling fast response without excessive delay.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If autonomous travel is used to improve productivity, then work efficiency increases, but the risk of unintended manual travel increases

Engineering Contradiction:
Improvework efficiencyVSAvoidunintended mode switching
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the detection parameter from steering angle to operation amount of the operation tool during autonomous travel. This parameter change significantly reduces the risk of unintended mode switching while maintaining the ability to detect genuine operator input. The operation amount parameter is less susceptible to noise and unintentional variations, thereby improving reliability and reducing unintended mode switching during autonomous travel operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the system continuously monitors the operation amount of the operation tool and compares it against the threshold value. This feedback loop allows the system to distinguish between normal autonomous travel variations and genuine operator intentions, providing reliable mode switching feedback that maintains productivity while preventing unintended manual travel activation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4335269A1Travel control method, travel control system, and travel control program
Publication Date: 2024.03.13 YANMAR HLDG CO LTD
  • EP4335269A1 patent drawingFigure 1
  • EP4335269A1 patent drawingFigure 2A~2B
  • EP4335269A1 patent drawingFigure 3~4

AI summary

[Problem] To provide a travel control method, a travel control system, and a travel control program that are capable of appropriately switching from autonomous travel to manual travel. [Solution] A reception processing unit 112 receives a user operation performed with respect to an operation tool that causes a work vehicle 10 to execute a predetermined motion. A motion processing unit 114 causes the work vehicle 10 to execute a motion corresponding to the user operation performed with respect to the operation tool. A travel processing unit 111 switches from autonomous travel to manual travel when a change amount relating to the operation tool corresponding to the user operation exceeds a threshold while the work vehicle 10 is performing autonomous travel. A setting processing unit 116 sets the threshold based on at least one of setting information and work information of the work vehicle 10.