Autonomous Tractor Path Planning on Inclined Field Headlands

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Solution Overview

Problem

Existing route generating systems for autonomous work vehicles do not adequately consider pitch-direction inclinations, leading to potential slide-down and departure outside the field during turns on inclined regions.

Innovation Solution

A route generating system that includes a work vehicle setting unit, altitude information obtaining unit, traveling direction setting unit, and region setting unit, which increases the width of connection paths in inclined regions and adjusts turning radii to prevent slide-down, with the option to designate arbitrary turning radii for enhanced control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the route generating system generates routes based only on work width in plan view without considering pitch-direction inclination, then the route generation is simple, but the work vehicle may slide down and depart outside the field during turns on inclined regions

Engineering Contradiction:
Improveprevention of vehicle departureVSAvoidroute generation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system changes the parameters used for route generation from simple 2D plan view coordinates to 3D spatial coordinates that incorporate altitude information. By obtaining altitude data for multiple positions and calculating pitch-direction inclinations, the system adjusts route parameters (such as turning radius and speed) to prevent slide-down on inclined surfaces, thereby resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system performs preliminary acquisition of altitude information and calculation of inclination angles before generating the actual travel route. By预先 (in advance) determining the pitch-direction inclination characteristics of the field, the system can pre-adjust route parameters to prevent slide-down, ensuring vehicle safety before the vehicle encounters the inclined terrain.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the system increases the width of connection paths and adjusts turning radii to prevent slide-down, then vehicle safety is improved, but the area required for autonomous travel increases

Engineering Contradiction:
Improvevehicle safety on inclined surfacesVSAvoidfield area required for travel
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The system applies local quality by adjusting connection path width and turning radius only in specific regions where pitch-direction inclination exceeds a threshold. Instead of uniformly increasing path widths across the entire field, the system locally modifies route parameters only where needed to prevent slide-down, thereby maintaining vehicle safety while minimizing the additional area required.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system implements partial action by applying safety measures (increased turning radius, speed reduction) only when and where the inclination threshold is exceeded, rather than applying them universally. This selective approach ensures vehicle safety on inclined surfaces while avoiding unnecessary area consumption in flat regions.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If the system obtains altitude information and calculates inclination degrees, then the accuracy of route generation is improved, but the measurement and detection difficulty increases

Engineering Contradiction:
Improveinclination measurement accuracyVSAvoidaltitude and inclination detection
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The system uses an intermediary approach by obtaining altitude information from external sources (such as GPS elevation data or pre-acquired digital elevation models) rather than directly measuring inclination angles. This intermediary altitude data serves as a basis for calculating inclinations, reducing the complexity of direct measurement while maintaining measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3567446B1Path generation system, and autonomous travel system enabling work vehicle to travel along path generated therewith
Publication Date: 2024.01.03 YANMAR POWER TECH CO LTD
  • EP3567446B1 patent drawingFigure 1
  • EP3567446B1 patent drawingFigure 2
  • EP3567446B1 patent drawingFigure 3

AI summary

In a route generating system (99), a work vehicle setting unit (36) sets vehicle information on a tractor (1). An altitude information obtaining unit (56) obtains altitude information on a field where an autonomous travel route is to be generated. A traveling direction setting unit (57) sets a traveling direction of the tractor (1) in the field. A region setting unit (58) sets, in the field, a plurality of regions including a work region where autonomous work paths being in parallel with the traveling direction are generated and headlands where connection paths each connecting corresponding ones of the autonomous work paths are generated. A region setting unit (58) sets the widths of the headlands (headland widths) based on the vehicle information, the altitude information, and the traveling direction, the widths of the headlands extending in parallel with the traveling direction.