Arrangement and Method for Determining Positions of the Teats of a Milking Animal

Abstract

An arrangement for determining positions of the teats of an animal is provided in a milking system comprising a robot arm for automatically attaching teat cups to the teats of an animal when being located in a position to be milked, and a control device for controlling the movement of the robot arm based on determined positions of the teats of the animal. The arrangement comprises a camera pair directed towards the teats of the animal for repeatedly recording pairs of images, and an image processing device for repeatedly detecting the teats of the animal and determining their positions by a stereoscopic calculation method based on the repeatedly recorded pairs of images, wherein the cameras of the camera pair are arranged vertically one above the other, and the image processing device is provided, for each teat and for each pair of images, to define the position of the lower tip of the teat in the pair of images as conjugate points, and to find the conjugate points along a substantially vertical epipolar line.

Description

TECHNICAL FIELD OF THE INVENTION[0001]The present invention generally relates to dairy farm robot milking and to automatic attachment of teat cups related thereto.DESCRIPTION OF RELATED ART AND BACKGROUND OF THE INVENTION[0002]In a known milking system, wherein teat cups are automatically attached to the teats of a milking animal to be milked, a robot arm with a gripper is provided to grip and hold teat cups during the attachment of the teat cups. A laser emitting laser light and a video camera provided to register laser light as reflected from the teats of the milking animal are mounted on the robot arm. By aid of a method known as laser triangulation, the positions of the teats can be calculated. The movement of the robot arm can then be controlled in response to the calculated positions to be capable of finding the teats for teat cup attachments.[0003]A drawback of such a milking system is that the camera, while being moved close to the milking animal, is exposed to dirt and poss...

AI Technical Summary

Benefits of technology

The present invention provides an arrangement and method for accurately detecting the positions of teats on a milking animal in a milking system. The arrangement and method use stereo vision and a stereoscopic calculation method based on recorded pairs of images. The invention is robust, effective, fast, precise, accurate, reliable, safe, easy to use, and of low cost. The invention can obtain a high number of correct teat cup attachments.

Problems solved by technology

A milking environment is a very difficult environment to perform stereo vision measurements.

The environment is non-clean and dirt may settle on camera lenses.

Further the cows are moving, and teats may not be visible to the cameras due to self-occlusion.

Another problem arises since each cow's physiology differs; the udders of the cows may be located at quite different locations, which put limitations on the positions of the cameras.

Another problem arises since both color and texture of the teats are similar to the surface of the udder, which means that teat detection will be an arduous task: the contrast is low and color filters are of no use.

The situation is even more complicated by the fact that the size, shape, color structure, morphological structure and texture may vary quite much from animal to animal.

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