Slack Arm Calibration System for Square Baler Tensioning

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Solution Overview

Problem

Calibration operations for slack arms in twine-tensioning systems of agricultural balers are complex and require improvement for accurate monitoring and maintenance of twine tension, as existing methods may not effectively account for accidental or incidental movements during calibration.

Innovation Solution

A calibration system and method that involves identifying and maintaining slack arms in specific calibration positions for predetermined time intervals using sensors, such as potentiometers, to determine accurate calibration settings and provide aural or visual indicators for operators, ensuring precise monitoring of slack arm positions during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional calibration methods are used for slack arms, then calibration can be performed, but calibration operations are complex and prone to errors from accidental movements

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by detecting slack arm movements and waiting for stabilization before initiating calibration. The controller monitors the slack arm position and only proceeds with calibration when the arm has been stationary for a predetermined time, preventing accidental movements from affecting calibration accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback by continuously monitoring the slack arm position through sensors and comparing it against calibration criteria. The controller receives real-time position data and determines when calibration conditions are met based on the arm maintaining a specific position for a predetermined duration, providing feedback control for accurate calibration.

Inventive Principle:
Principle #23Feedback

2Loss of information

If electronic monitoring devices replace physical flags, then monitoring capability is improved, but calibration complexity increases

Engineering Contradiction:
Improvevisual indicator accuracyVSAvoidelectronic monitoring complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The system replaces mechanical visual indicators (physical flags) with electronic monitoring devices. Sensors detect slack arm position and the controller processes this data to provide electronic visual indicators, eliminating the need for physical flags while improving monitoring accuracy and reducing information loss.

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

3Loss of time

If calibration is performed without waiting for slack arm stabilization, then calibration time is reduced, but calibration accuracy decreases

Engineering Contradiction:
Improvecalibration timeVSAvoidcalibration precision
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The system performs a preliminary waiting period after detecting slack arm movement before initiating calibration. The controller monitors the arm position and only proceeds with calibration when the arm has been stationary for a predetermined time, ensuring stabilization without significantly extending total calibration time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback control by continuously monitoring slack arm position and determining when calibration conditions are met. The controller receives real-time position data and automatically initiates calibration when the arm maintains a specific position for the required duration, optimizing both accuracy and time efficiency.

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 allows for accurate calibration of slack arms, reducing errors and improving the monitoring of twine tension, thereby enhancing the operational efficiency and reliability of the baler's knotting process.

Implementation Method 1

The first or second movement of the slack arm may be identified based upon a voltage change in a signal from the sensor

Methodology Applied
Scientific EffectPotentiometer voltage signal:

Data Source

PatentEP2936971B1Calibration system for a tensioning system on a square baler and method for such
Publication Date: 2018.06.27 DEERE & CO
  • EP2936971B1 patent drawingFigure 1
  • EP2936971B1 patent drawingFigure 2
  • EP2936971B1 patent drawingFigure 3

AI summary

A calibration system for a tensioning system (32) on a square baler (12) and method for such is disclosed. A first movement of a slack arm (44) of the tensioning system (32) may be identified (206). It may be determined that the slack arm has been maintained in a first calibration position for a first predetermined time interval (216), and a first calibration setting for the slack arm (44) may be determined based upon the first calibration position (220). A second movement of a slack arm (44) of the tensioning system (32) may be identified (226). It may be determined that the slack arm (44) has been maintained in a second calibration position for a second predetermined time interval (232), and a second calibration setting for the slack arm (44) may be determined based upon the identified second calibration position (236).