Hydraulic Load Estimation via Cylinder Pressure and Link Angles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for determining load on linkage bearings in working machines, such as wheel loaders and excavators, require a complex and costly array of sensors, making them impractical for widespread implementation and limiting their effectiveness in optimizing operational efficiency and extending component life.

Innovation Solution

A method that uses a reduced number of sensors to determine load on linkage bearings by measuring pressures in hydraulic cylinders and link angles, calculating perpendicular force components, and applying predetermined constants to estimate bearing loads, allowing for efficient load monitoring without complex sensing systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a complex sensor network is used to determine bearing loads, then measurement precision is improved, but device complexity increases and cost increases

Engineering Contradiction:
Improvebearing load measurement precisionVSAvoidsensor network complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential measurements needed for bearing load determination - specifically hydraulic cylinder pressures and linkage angles - while eliminating the need for complex sensor networks, load pins, bending bridges, and other unnecessary sensing equipment described in prior art

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces direct mechanical measurement systems (load pins, bending bridges, strain gauges) with a computational approach that uses hydraulic pressure sensors and angle measurements combined with mathematical calculations to determine bearing loads

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a comprehensive sensor network is deployed, then measurement precision is improved, but ease of manufacture deteriorates

Engineering Contradiction:
Improvebearing load measurement precisionVSAvoidsystem implementation ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts only the essential measurements needed for bearing load determination - specifically hydraulic cylinder pressures and linkage angles - while eliminating the need for complex sensor networks, load pins, bending bridges, and other unnecessary sensing equipment

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses inexpensive, readily available sensors (pressure sensors and angle sensors) instead of expensive, complex measurement equipment, making the system easier to manufacture and implement

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If multiple sensors are used to monitor linkage wear, then measurement precision is improved, but loss of substance increases

Engineering Contradiction:
Improvewear monitoring precisionVSAvoidcomponent wear
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The patent implements a feedback mechanism where bearing loads are continuously determined and used to monitor linkage component wear, enabling operators to adjust operations to minimize wear while maintaining measurement precision

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables cost-effective and efficient determination of bearing loads in working machines, reducing wear and tear, and extending the life of components by optimizing operational efficiency without the need for extensive sensor networks.

Implementation Method 1

determining at least one pressure in a first hydraulic cylinder and at least one pressure in a second hydraulic cylinder arranged to control the linkage

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a linkage configured to be connected to an implement

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentEP3645796B1A method and a system for determining a load in a working machine
Publication Date: 2024.08.21 VOLVO CONSTRUCTION EQUIPMENT AB
  • EP3645796B1 patent drawingFigure 1
  • EP3645796B1 patent drawingFigure 2
  • EP3645796B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for determining a load in a working machine (101) comprising a linkage (106) configured to be connected to an implement (107). The method comprises: determining (S1) at least one pressure in a first hydraulic cylinder (108) and at least one pressure in a second hydraulic cylinder (110) arranged to control the linkage and determining (S2) at least one link angle between at least two links in the linkage. The method further comprises, for a known linkage configuration and for a selected linkage bearing, for each of the first and second hydraulic cylinder, determining (S3) at least two perpendicular force components acting on the selected linkage bearing, based on the determined at least one pressure in each of the first and second cylinders and the at least one link angle; and determining (S4) a load on the selected linkage bearing as a linear combination of the determined at least two perpendicular force components using predetermined constants for the linear combination.