Lift Assembly Self-Leveling Control for Stable Bucket Angle

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Solution Overview

Problem

Conventional work vehicles face challenges in maintaining a constant angular position of implements, such as buckets, due to poor system responsiveness and imprecise control, especially when accommodating non-linear operational dynamics of lift assemblies with Z-bar linkages, leading to unintended material dumping.

Innovation Solution

A closed-loop control system that determines a tilt transition boom angle and generates valve command signals to control the movement of tilt cylinders, ensuring the implement maintains a target angular orientation as the boom is raised or lowered, using a combination of feed-forward and feedback control algorithms to improve responsiveness and precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If conventional control algorithms are used to automatically maintain implement position, then automation is improved, but system responsiveness and control precision deteriorate

Engineering Contradiction:
Improveautomatic implement position controlVSAvoidimplement position control precision
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent implements a closed-loop control system that continuously monitors the actual implement angle using sensors and compares it to the desired target angle. The controller automatically adjusts the tilt cylinder position based on the angle error, creating a feedback mechanism that maintains precise implement positioning throughout the boom's travel range, thereby resolving the precision deterioration issue while maintaining automation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system pre-calculates the desired implement angle for each boom position using feed-forward control algorithms. By determining the required tilt cylinder position in advance based on the current boom angle and desired implement orientation, the system proactively compensates for geometric relationships, improving both responsiveness and control precision before errors occur.

Inventive Principle:
Principle #10Preliminary action

2Extent of automation

If conventional control algorithms are used to automatically maintain implement position, then automation is improved, but system responsiveness deteriorates

Engineering Contradiction:
Improveautomatic implement position controlVSAvoidsystem responsiveness
Core Design Contradiction:
Extent of automationVSSpeed

Solution Approach 1:

The control system operates continuously by constantly monitoring boom angle, calculating the desired implement angle, and adjusting the tilt cylinder without interruption. This continuous control action ensures that the implement maintains its target orientation throughout the entire boom travel range, eliminating delays and improving system responsiveness while maintaining full automation.

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If manual adjustment of implement position is used, then system complexity is reduced, but operational precision and reliability deteriorate

Engineering Contradiction:
Improvecontrol system complexityVSAvoidimplement position maintenance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The control system is designed to be self-regulating by automatically sensing the implement angle, comparing it to the desired angle, and adjusting the tilt cylinder without operator intervention. This self-service capability maintains reliable implement positioning throughout operation, eliminating the unreliability of manual adjustment while keeping the system complexity manageable through the use of standard sensors and controllers.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4105388B1Work vehicle with improved bi-directional self-leveling functionality and related systems and methods
Publication Date: 2024.08.07 CNH IND ITALIA SPA
  • EP4105388B1 patent drawingFigure 1
  • EP4105388B1 patent drawingFigure 2
  • EP4105388B1 patent drawingFigure 3

AI summary

A method for automatically adjusting the position of an implement of a lift assembly of a work vehicle includes determining a tilt transition boom angle for the lift assembly, determining a closed-loop control signal associated with controlling movement of the implement based at least in part on the tilt transition boom angle, generating a valve command signal based at least in part on the closed-loop control signal, and controlling an operation of at least one valve associated with the implement based at least in part on the valve command signal to maintain the implement at a target implement angle as a boom of the lift assembly is being moved across a boom travel range.