Automatic Milking Tool Offset Compensation Using 3D Teat Imaging

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Solution Overview

Problem

Automatic milking systems face challenges in accurately determining the position of milking tools, leading to potential animal injury and impaired milk production due to insufficient accuracy in attaching and detaching teat cups, which is exacerbated by tolerances and wear in the milking robot's grippers.

Innovation Solution

A system utilizing a camera, such as a time-of-flight or stereo camera, to register 3D image data of the teat and process image data to calculate the offset between the tool reference position and the actual position of the milking tool, ensuring precise attachment and detachment by identifying a predefined part of the teat that meets specific measurement criteria, thereby providing consistent and accurate tool position data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If technical specifications and theoretical position coordinates are used for tool positioning, then the system is simple to operate, but the measurement precision is insufficient due to tolerances and wear

Engineering Contradiction:
Improvetool position accuracyVSAvoidposition determination system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical position determination methods (based on technical specifications and theoretical coordinates) with an optical measurement system using cameras and image processing. This substitution enables precise measurement of actual tool positions and teat locations, compensating for tolerances and wear without requiring complex mechanical adjustment mechanisms

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

Solution Approach 2:

The patent creates visual copies (images) of the actual tool positions and teat locations using cameras. By capturing and processing images, the system obtains accurate positional data that reflects the real state of the system, including any deviations caused by tolerances or wear, without needing to physically measure or adjust each component

Inventive Principle:
Principle #26Copying

2Reliability

If the milking robot uses fixed position data from technical specifications, then the device complexity is low, but the reliability of attachment is insufficient

Engineering Contradiction:
Improveattachment reliabilityVSAvoidposition calibration system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the actual positions of tools and teats are continuously measured using cameras and image processing. This real-time positional information is fed back to the control system, which adjusts the robot's movements to ensure reliable attachment, compensating for any deviations from theoretical positions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary position determination and calibration before the actual milking operation. By capturing images and calculating actual positions in advance, the system prepares accurate positional data that ensures reliable attachment when the robot approaches the teats, preventing attachment failures

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the system does not account for tool position offsets, then the ease of operation is high, but the productivity is impaired due to failed attachments

Engineering Contradiction:
Improvemilking efficiencyVSAvoidoffset compensation system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces manual positioning and trial-and-error attachment methods with an automated optical measurement and control system. Cameras capture tool positions, image processing calculates offsets, and the control system automatically compensates, maintaining high productivity without requiring complex manual adjustments or repeated attempts

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

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 solution ensures reliable and efficient attachment of milking tools, reduces the risk of animal injury, and allows for continuous adjustment of tool positions over time, maintaining high-quality milk production by providing robust and accurate data for tool calibration.

Implementation Method 1

a camera, which may be a time-of-flight (TOF) camera, a stereo camera, a laser-assisted two-dimensional (2D) camera, a 2D camera in conjunction with structured-light illumination or an ultrasonic imaging device is configured to register three-dimensional (3D) image data representing a teat

Methodology Applied
Scientific EffectOptical imaging: Photography

Implementation Method 2

a camera, which may be a time-of-flight (TOF) camera

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 3

a stereo camera

Methodology Applied
Scientific EffectStereo vision: Parallax

Data Source

PatentEP4145987B1System and computer-implemented method for determining an offset for a milking tool in an automatic milking machine
Publication Date: 2024.03.27 DELAVAL HLDG AB
  • EP4145987B1 patent drawingFigure 1~2f
  • EP4145987B1 patent drawingFigure 3a~8
  • EP4145987B1 patent drawingFigure 4~7b

AI summary

An offset for a first milking tool in a tool carrier of an automatic milking machine is determined as a spatial vector between a tool reference position (TRP) and an estimated actual position (TAP) of the milking tool. Three-dimensional image data is registered that represents a teat (T) during attachment to and/or detachment from the milking tool. The image data is processed by searching, within a search zone, for a predefined part (MP) of the teat (T) while the teat (T) is attached to the milking tool. Provided that the predefined part (MP) fulfills a measurement criterion, a distance (d0ff) is calculated between a specific point of the predefined part (MP) and the tool reference position (TRP). The offset is then determined based on the calculated distance (doff).