Construction Machine Swing Control System for Precise Stop Positioning

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Solution Overview

Problem

Existing construction machine control systems fail to adequately consider changes in swing inertia and stop target position during swing operations, leading to potential contact with cargo stands or approaching objects, and require high operator concentration, which can result in delayed detection of surrounding objects.

Innovation Solution

A control system for construction machines that includes sensors to detect swing angles and elevation angles, a swing stoppability determination section to assess whether the swing can be stopped at a desired angle, and a work implement control section to limit or prohibit actions that increase swing inertia, allowing the work implement to execute contraction actions when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the operator manually controls the swing operation to stop the upper swing structure at a desired position, then the swing can be stopped at the target position, but the operator requires high degree of concentration which diminishes monitoring awareness of surroundings

Engineering Contradiction:
Improveswing stop position precisionVSAvoidoperator monitoring awareness
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The swing automatic stop device enables the swing control system to automatically determine the stop starting position and calculate the stop target position based on current swing position and inertia characteristics, eliminating the need for continuous operator intervention and concentration while maintaining precise stop positioning

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the operator's manual judgment and control with an automatic control system that uses sensors and controllers to detect swing position, calculate inertia-based stop parameters, and automatically adjust the swing stop target position, substituting human concentration requirements with automated mechanical-electrical control

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

2Adaptability or versatility

If the operator stops the swing operation at different timing, then the operation flexibility is maintained, but the swing stop angle varies due to swing inertia making precise positioning difficult

Engineering Contradiction:
Improveswing operation flexibilityVSAvoidswing stop angle precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The swing automatic stop device continuously detects the current swing position using angle sensors and uses this feedback information to dynamically calculate the stop starting position and stop target position, ensuring precise positioning regardless of when the operator initiates the stop operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the stop target position parameter based on real-time swing position and calculated swing inertia, allowing the system to compensate for variations in stop timing and maintain precise stop angle accuracy through parameter optimization

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the work implement executes extension action during swing operation, then the work efficiency is improved, but the swing inertia increases causing the swing to overshoot the desired stop position

Engineering Contradiction:
Improvework efficiencyVSAvoidswing stop position accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The swing automatic stop device dynamically determines whether to permit extension actions based on real-time swing state and calculated stop parameters, adaptively adjusting work implement control to prevent inertia increase that would cause overshoot while maintaining work efficiency when conditions permit

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary determination of swing stoppability before allowing work implement actions, calculating in advance whether extension actions would increase swing inertia to a level that prevents accurate stopping, and preemptively controlling the work implement to avoid overshoot conditions

Inventive Principle:
Principle #10Preliminary action

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 system effectively suppresses the increase of swing inertia, enabling the upper swing structure to be stopped at a desired angle, reducing the risk of contact with cargo stands or objects and improving operator awareness by reducing the need for high concentration during operations.

Implementation Method 1

an inertia calculating section that calculates swing inertia on the basis of a relationship between swing angular velocity and swing angular acceleration

Methodology Applied
Scientific EffectInertia: Inertia

Implementation Method 2

a hydraulic pump; work implement control valves and a swing control valve configured to exercise control of flow rates and directions of hydraulic fluids supplied from the hydraulic pump

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP3382107B1Construction machine with a control system for the superstructure
Publication Date: 2021.01.06 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3382107B1 patent drawingFigure 1
  • EP3382107B1 patent drawingFigure 2
  • EP3382107B1 patent drawingFigure 3

AI summary

A control system for a construction machine that can stop an upper swing structure at a desired swing stop angle is provided. A main controller includes: a swing stop target angle setting section that sets a swing stop target angle that is a target angle at which an upper swing structure is stopped; a swing control section that outputs a drive command to a control valve in such a manner that a speed reduction of swing of the upper swing structure is executed; a swing stoppability determination section that reads an angle signal of the upper swing structure with respect to an undercarriage detected by a first angle sensor and an angle signal of a work implement detected by a second angle sensor, and that determines whether the swing of the upper swing structure can be stopped at the swing stop target angle on the basis of these signals; and a work implement control section that outputs drive command signals to control valves in such a manner an extension action of the work implement in a swing radial direction is prohibited or a contraction action of the work implement in the swing radial direction is executed in response to a signal that indicates whether the swing can be stopped and that is determined by the swing stoppability determination section.