Working Vehicle Reverse Auto-Steering Locked by PTO State

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Solution Overview

Problem

The challenge of stabilizing automatic steering during rearward travel of a working vehicle, particularly when the power take-off shaft is rotating at high speed, poses safety risks due to operator visibility issues and potential danger.

Innovation Solution

The working vehicle is equipped with a controller that integrates a position detector using satellite positioning systems and an automatic steering mechanism, allowing for stable and safe rearward travel by adjusting the steering based on detected vehicle position and enabling safe operation even when the operator's view is obstructed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the working vehicle travels rearward in automatic steering with the PTO shaft rotating at high speed, then the working implement can operate efficiently, but the automatic steering becomes unstable and the operator may be in danger when looking back

Engineering Contradiction:
Improveworking implement operation efficiencyVSAvoidautomatic steering stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the PTO shaft rotation state as a separate control parameter from the automatic steering control. The controller monitors PTO shaft rotation speed and uses this information to determine whether to allow automatic steering during rearward travel. By separating the control of PTO operation from automatic steering authorization, the system ensures that automatic steering remains stable only when PTO shaft rotation is at a safe level, thus resolving the contradiction between working implement efficiency and steering stability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If the working vehicle travels rearward in automatic steering with the PTO shaft rotating at high speed, then the working implement can operate efficiently, but the operator's safety is compromised due to visibility issues and potential danger

Engineering Contradiction:
Improveworking implement operation efficiencyVSAvoidoperator safety risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by preventing automatic steering from operating during rearward travel when the PTO shaft is rotating at high speed. The controller proactively checks the PTO shaft rotation state before allowing automatic steering engagement, and blocks the automatic steering function when high-speed PTO rotation is detected. This preemptive control measure eliminates the safety hazard before it can occur, while still allowing high-speed PTO operation during forward travel when safety risks are minimal.

Inventive Principle:
Principle #9Preliminary anti-action

3Adaptability or versatility

If automatic steering is allowed during rearward travel with high-speed PTO rotation, then operational flexibility is improved, but control stability deteriorates

Engineering Contradiction:
Improveautomatic steering operational flexibilityVSAvoidsteering control stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic control by making the availability of automatic steering dependent on real-time PTO shaft rotation conditions. The controller continuously monitors PTO shaft speed and dynamically adjusts the automatic steering authorization accordingly - allowing automatic steering during rearward travel only when PTO rotation is below a predetermined threshold. This dynamic adaptation maintains steering control stability while preserving operational flexibility under safe conditions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4272528B1Work vehicle
Publication Date: 2026.01.28 KUBOTA CORP
  • EP4272528B1 patent drawingFigure 1
  • EP4272528B1 patent drawingFigure 2
  • EP4272528B1 patent drawingFigure 3

AI summary

To stably and safely perform automatic steering during rearward travel of a working vehicle (1), the working vehicle (1) includes a vehicle body (3) to be manually steered with a steering wheel (30) or automatically steered to travel forward or rearward, a prime mover (4) on the vehicle body, a working implement (2) supported on the vehicle body, a power take-off (PTO) shaft (16) to transmit power from the prime mover to the working implement, and a controller (60) to control automatic steering of the vehicle body and driving of the PTO shaft, wherein the controller allows the automatic steering during rearward travel of the vehicle body when the PTO shaft is in a stopped state, and prohibits the automatic steering during rearward travel of the vehicle body when the PTO shaft is in a driven state.