Excavator Swing Control Apparatus Stop Position Precision

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Solution Overview

Problem

Construction machines, such as excavators, face the challenge of varying stop positions for their upper swing structures due to the timing of operator input for stop commands, requiring additional operations to align with desired positions.

Innovation Solution

A swing control apparatus and method that calculates an optimum stop starting position based on mass moment of inertia and maximum torque, or through a lookup table, to determine a stop target position, ensuring the upper swing structure can be stopped within a predetermined range regardless of when the stop command is given.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the upper swing structure is stopped at a certain point after performing a swing operation at a predetermined angle from the stop starting time point, then the stop operation can be executed, but the stop position differs depending on the time point where the stop command starts, requiring additional driving operations

Engineering Contradiction:
Improvestop operationVSAvoidstop position
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The control apparatus calculates and determines the optimal stop starting position in advance based on the desired stop position and current machine state. This preliminary calculation ensures that when the stop command is executed, the upper swing structure will naturally reach the correct stop position without requiring additional adjustment operations, thereby resolving the contradiction between ease of operation and stop position precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control apparatus continuously monitors the actual position of the upper swing structure and compares it with the target stop position. Based on this feedback, the system dynamically adjusts the stop starting position calculation to compensate for timing variations, ensuring consistent stop position accuracy regardless of when the stop command is given

Inventive Principle:
Principle #23Feedback

2Device complexity

If the stop position is determined by the timing of the stop command, then the control system can be simple, but the stop position varies and additional operations are required

Engineering Contradiction:
Improvecontrol systemVSAvoidoperation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system performs preliminary calculation of the optimal stop starting position based on the desired stop position and current machine state. This advance determination eliminates the need for additional adjustment operations after the stop command, thereby improving operation efficiency without significantly increasing control system complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control apparatus automatically calculates and adjusts the stop starting position based on real-time machine state parameters, making the system self-regulating. This self-service capability ensures consistent stop position accuracy without requiring complex external intervention or additional manual operations

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2594697B1Swing control apparatus and method of construction machinery
Publication Date: 2021.12.15 VOLVO CONSTRUCTION EQUIPMENT AB
  • EP2594697B1 patent drawingFigure 1~2
  • EP2594697B1 patent drawingFigure 3~5
  • EP2594697B1 patent drawingFigure 6~7

AI summary

A swing control apparatus and a swing control method for a construction machine are provided. The swing control apparatus includes a start position estimation unit, a stop target position calculation unit, and a swing motor position control unit. Even if an operator releases a lever or commands a stop at different times, an upper swing structure of the construction machine (for example, excavator) can be stopped within a predetermined range, and thus the inconvenience caused by an additional driving operation, which is required as the stop position differs according to the time point where the stop command starts, can be solved.