DK181541B1

DK181541B1 - A system and a method for the grading of sliced products

Info

Publication number: DK181541B1
Application number: DKPA202200882A
Authority: DK
Inventors: Askjær Hass Morten; Arild Jørgensen Morten
Original assignee: Teknologisk Inst
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2024-04-22
Also published as: DK202200882A1

Abstract

This invention relates to a system and a method for the grading of sliced food products, for finding foreign objects and/or for determining the quality grade of each slice in real-time during the slicing process using vision technology including image analysis, optionally combined with the use of machine learning and/or the implementation of artificial intelligence (AI).

Description

DK 181541 B1 1

A SYSTEM AND A METHOD FOR THE GRADING OF SLICED PRODUCTS

TECHNICAL FIELD

BACKGROUND ART

There are various methods to detect surface characteristics on food items as described in, e.g., US2013133490, WO2011053601, WO2013023778, WO2014082012,

WO2015167585, WO2016139611, US2017108855, WO2018087390, and WO2020007804.

Methods are also known for detecting foreign bodies in food items as described in e.g., WO2017048783, WO2018022598, and WO2019171312.

WO2007148041 discloses a vision system for viewing the end face of a food product mounted in a machine. However, the grading system and method described herein, wherein the food product is fully exposed for the recording of images by the imaging means for grading of the food product, is not disclosed.

Finally, disc cutting equipments are known from and described in, e.g.,

WO2017127824, and WO2020225530.

It is generally associated with inherent challenges to perform realtime inspection or to ensure that there are no foreign objects concealed in sliced meat products. Due to the speed of the process and the presence of bulky mechanical slicing tools, there are physical barriers to examining the surfaces of each cut piece.

On the one hand, the foreign bodies may be embedded in the original meat product, or the foreign bodies may be added at random during the cutting process.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a system for grading sliced food products.

In the context of this invention, grading includes quality control, quality assessment, and/or the recognition of foreign objects in a sliced food product.

The grading system of the invention is for finding foreign objects and/or for determining the quality grade of each slice in real-time during the slicing process using

DK 181541 B1 2 vision technology including image analysis, optionally combined with the use of machine learning and/or the implementation of artificial intelligence (AI).

Although the food product is sometimes partially or completely covered by the cutting tool, the system according to the invention allows the recording of one or more images of the total cutting surface for use in an inspection and quality assessment due to the use of a delaying trigger device, which device enables a delay of the image recording to a time when the cutting surfaces are fully exposed to recording.

Cutting speed may vary from product to product. Depending on the product in question, the cutting speed may vary, e.g., of from about 50 to about 2000 rpm. These variations in speed result in large differences in the angular velocity at which the rotatable cutting tool moves at a given time, which makes it difficult to use a simple time offset as a starting point for delaying the image capturing time.

Using a triggering device according to the invention, the system of the invention allows for a desired delay no matter at what speed the slicer proceeds, and independent of a delay measured in angular velocity or time delay.

The output of an analysis according to this invention can be used in the production line for discarding slices containing foreign objects and/or for sorting the sliced products into user-defined products grades.

The grading system of the invention may be used as an add-on device, or as a built-in device in existing slicing equipment.

The grading system of the invention is capable of analysing a given area on the slicer cutting rail, including food products lying in a cutting rail, ready for being sliced.

Moreover, the analysed area in the cutting rail may include several individual products that may be sliced simultaneously, and the grading system of the invention may perform dual-sided analysis, e.g., by analysing the front end of the next sliced piece and the back end of the previously sliced piece lying on the conveyor, and each individual slice may be analysed separately during the slicing process.

The grading system of the invention may be characterised by comprising the essential elements described in the claims, and which system is characterised in that the food product (9) is fully exposed for the recording of one or more images by the imaging means (5) for grading of the food product (9).

In another aspect, the invention relates to a method for the grading of sliced food products, which method comprises the process steps described in the claims, which method is characterised in that the system for grading the sliced food products that is comprising the rotatable cutting device (2), the cutting device detector (3), the triggering device (4), the imaging means (5), the processing means (6), the lighting means (7), and the conveying means (8) is the system according to claim 1.

DK 181541 B1 3

Other objects of the invention will be apparent to the person skilled in the art from reading the following detailed description and accompanying drawings.

Any combination of two or more of the embodiments described herein is considered within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further illustrated by reference to the accompanying drawing, in which Fig. 1 shows an overview of the grading system of the invention.

DETAILED DISCLOSURE OF THE INVENTION

The system of the invention

In its first aspect, the invention relates to a system for grading sliced food products. In the context of this invention, grading includes quality control, quality assessment, and/or the recognition of foreign objects in a sliced food product.

The system of the invention may be characterised by comprising the following essential elements: a. a rotatable cutting device (2), configured for slicing a food product (9); b. a cutting device detector (3), in communication with the triggering device (4), which cutting device detector is configured for monitoring the rotation of the rotatable cutting device (2) and for transferring the signal to the triggering device (4); c. a triggering device (4), in communication with the cutting device detector (3) and, optionally, in communication with the processing means (6), which triggering device is configured for delaying the signal received from the cutting device detector (3); d. an imaging means (5), in communication with the triggering device (4) and with the processing means (6), and, optionally, in communication with the lighting means (7), which imaging means is configured for recording one or more images of the food product (9) and for transmitting the obtained data to the processing means (6), and, optionally, configured for activating the lighting means (7) for illumination of the food product (9) during exposure time; e. a processing means (6), in communication with the triggering device (4) and with the imaging means (5), which processing means is configured for performing soft-ware calculation and/or for performing image assessment for carrying out grading sliced food products; f. a lighting means (7), optionally in communication with the imaging means (5), and/or in communication with the processing means (6), which lighting means is configured for illuminating the food product (9) during the image acquisition;

DK 181541 B1 4 g. a conveying means (8), optionally in communication with the processing means (6), which conveying means is configured for receiving and forwarding the sliced food product (9A); and the system of the invention may further be characterised in that the food product (9), i.e., the entire food product (9) and/or the sliced/cut food product (9A), is fully exposed for recording one or more images by the imaging means (5) for grading (i.e., inspection and quality assessment) of the food product (9).

The rotatable cutting device

The cutting device/knife (2) for use according to the invention shall be configured for slicing the food product (9). This action is normally accomplished by use of a rotatable cutting and/or slicing device, and such devices are well known in the industry and readily commercially available, as described in, e.g., WO2017127824 and

WO2020225530.

The cutting device detector

The cutting device detector (3) for use according to the invention shall be configured for monitoring the rotation of the cutting device (2) and for transmitting the obtained signal to the triggering device (4).

Such detectors, e.g., a building detector, or a commercially available detector such as a photoelectric sensors or photoelectric switches and represents devices that are turned off and on by the presence or absence of received light.

The monitoring action according to the invention may, e.g., be accomplished by emitting a light beam that is broken for each revolution of the cutting device (2), i.e., detects each single rotation of the cutting device, and detects when the rotating slicer knife (2) passes the detector (3).

In another embodiment, the cutting device detector (3) is constituted by a signal emitted from the rotatable cutting device (2). Since most cutting devices knows the exact position of the knife and often will be able to signal this position, e.g., the upper position of the knife, the rotatable cutting device (2) can be said to also include an inherent cutting device detector (3).

The triggering device

The triggering device (4) of the invention represents a special electronic unit that can delay the signal received from the cutting device detector (3) for a predetermined time (fixed time delay mode), or for a predetermined number of degrees of rotation (fixed degree delay mode) of the rotatable cutting device (2).

DK 181541 B1

The triggering device (4) of the invention comprises software, stored on a CPU, that monitors the speed of the rotatable cutting device (2) and calculates the optimal triggering time based on information stored in the processing means (6).

In the fixed timing delay mode, the triggering device is set to delay the signal 5 obtained by the cutting device detector (3) by the amount of time, defined during the initial setup of the triggering device (4) by the processing means (6).

In the fixed degree delay mode, the angle delay is calculated using the rotating cutting device (2) angular velocity. The triggering device measure the rotatable cutting device (2) frequency (RPM), and the build in software calculate the current delay needed for delaying the trigger signal from the cutting device detector (3), the number of degrees defined during the initial setup by the processing means (6).

The imaging means/camera

The imaging means (5) for use according to the invention shall be configured for recording one or more images of the food product (9) in question, i.e., the entire food product (9) and/or the sliced/cut food product (9A), and for transmitting the obtained data to the processing means (6).

The imaging means (5) for use according to the invention may also be configured for activating the lighting means (7) for illumination of the food product (9) during the entire exposure time.

To fulfil its various purposes, the imaging means (5) for use according to the invention shall be in communication with the triggering device (4) and with the processing means (6), and, optionally, in communication with the lighting means (7).

The imaging means (5) for use according to the invention may be contemplated as a part of a machine vision system comprising hardware and software components.

The lens captures the image and presents it to the sensor in the form of light. The sensor in a machine vision camera converts this light into a digital image, which is then sent to the processing means (6) for analysis.

After acquisition of the image, the imaging means (5) sends the image data to the processing means (6) for further processing.

The processing means

For receiving input from, and for guiding the relevant devices used according to the invention, the system of the invention comprises one or more processing means (6).

If two or more processing means are employed, these processors may be in inter- communication with one or more of the other processing means. The processing means (6) for use according to the invention may be any commercially available processor/PC/PLC.

DK 181541 B1 6

The processing means (6) for use according to the invention shall be configured for performing soft-ware calculation and/or for performing image assessment for carrying out grading sliced food products, and shall be capable of processing, analysing, and measuring various characteristics for decision making.

In one embodiment, the food object is analysed for foreign objects, e.g., plastic objects. This may be accomplished using traditional pixel by pixel algorithms, or by using artificial intelligence (AI) solutions.

In another embodiment, the food product, including the entire food product (9) and/or the sliced/cut food product (9A), is analysed for fat and meat contents, and for calculating, e.g., a ratio and ratio result for individual food product slices (9A). This may, e.g., be accomplished using a pre-trained neural network for determining the fat/meat ration.

In a third embodiment, the processing means (6) may, e.g., calculate and set the actual trigger delay angle to the trigger device (4). The trigger delay angle may be used by the trigger device (4) to dynamically calculate the delay time used for triggering the imaging means (5). The actual calculated delay time may, e.g., be calculated using the actual knife rotation speed along with the set delay angle.

The rotation speed of the rotatable cutting device (2) may also be determined by the processing means (6) and may be used for correct precise triggering of the camera independent of the speed of the rotatable cutting device (2)

The lighting means/light

The lighting means (7) for use according to the invention may be any available light source, including the ambient light and/or specific light sources, that can be configured for illuminating the food product (9), i.e., the entire food product (9) and/or the sliced/cut food product (9A), that may be, e.g., meat slices, during the image acquisition.

Lighting illuminates the part of the food product to be inspected and allows its features to stand out so it can be clearly seen by the imaging means (5).

Moreover, the lighting means/light for use according to the invention shall be configured for illuminating the food product at least during the image assessment process, where images are recorded by the imaging means (5).

In the context of this invention, a sufficient illumination may be supplied by a relatively dim ambient light, or by a flashlight capable of providing light during the entire image acquisition process, or a strong flash of light during a part of the image acquisition process.

DK 181541 B1 7

The conveying means

The conveying means (8) for use according to the invention shall be configured for transporting, i.e., receiving and forwarding, the sliced food product.

In one embodiment, the conveyor belt is advanced with a constant speed, enabling removal of the sliced products.

In another embodiment, the conveyor belt is equipped with an encoder (8B), allowing it to be in operation with the processing means (6), via a signal (8C) emitted by the encoder. This allows for the processing means to calculate the exact location of each sliced/cut food product (9A), as it is led away by the conveying means (8). By knowing the speed of the conveyor belt, and the release of each sliced/cut food product, the processing means will be able to allocate a given time stamp to each sliced/cut food product, and subsequently to calculate the exact position of the sliced/cut food product (9A) on the conveying belt.

The disposal/discharge device

In a third embodiment, the system of the invention further comprises a disposal/discharge device (8A), in communication with the processing means (6), which disposal device is configured for removing/discharging a sliced/cut food product (9A) that is specifically identified and designated by the processing means (6).

By knowing the speed of the conveyor belt by input (8C) from the encoder (8B), the disposal/discharge device for use according to the invention will be able to calculate the exact position of the sliced/cut food product (9A) on the conveying belt.

The disposal/discharge device (8A) for use according to the invention may, e.g., function by ejecting a scraper/pusher, that can hit and remove the identified work piece (9A) from the conveying means (8), and, e.g., for collect the discharged and ejected products in a waste container.

In another embodiment, the processing means will reverse the conveyer belt for discarding the sliced/cut food product in a waste container.

The method of the invention

In another aspect, the invention relates to a method for the grading of sliced food products. In the context of this invention, grading includes quality control, quality assessment, and/or the recognition of foreign objects in a sliced food product.

In a preferred embodiment, the method of the invention is accomplished by use of the system of the invention.

The method of the invention may be characterised by comprising the following process steps:

DK 181541 B1 8 i. providing the food product (9) to be graded and subjecting the food product (9) to analysis by an imaging means (5), which imaging means (5) is in communication and/or cooperation with a processing means (6), while the food product (9) is being illuminated by use of a lighting means (7); ii. slicing the provided food product (9) by means of a rotatable cutting device (2) to obtain one or more sliced/cut food products (9A), while the rotatable cutting device (2) is being monitored by a cutting device detector (3) that is in communication with a triggering device (4), which triggering device is configured for delaying the signal received from the cutting device detector (3); iii. processing/analysis of the data obtained in step i by the imaging means (5) for grading of the subjected food product (9) by use of a processing means (6) that is in communication/cooperation with the imaging means (5) and, optionally, with the triggering device (4); and iv. collecting the sliced/cut food product (9A) on a conveying means (8) configured for forwarding the sliced food product for further processing down the production line.

The method of the invention may be further characterised in that the method of the invention offers the possibility to fully expose the food product (9) during the recording of images by the imaging means (5), due to the presence of the triggering device (4), allowing delay of the signal received from the cutting device detector (3).

In another embodiment, the method of the invention further comprises the use of a disposal/discharge device (8A), configured for disposal/discharge of the sliced/cut food products (9A) that are identified by the imaging means (5) and by the processing means (6) as being outside the product specifications, or that contain foreign objects.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is further illustrated by reference to the accompanying drawing, in which:

Fig. 1 shows an overview of the grading system of the invention: Rotatable cutting device/knife (2); Cutting device detector/photoelectric switch (3); Detector signal (3A);

Trigger device/trigger (4); Controlled trigger signal (4A); Imaging means/camera (5);

Image transfer/signal (5A); Light trigger signal (5B); Processing means/PC/controller (6);

Trigger signal (6A); Disposal device signal (6B); Lighting means/light (7); Conveying means/conveyor belt (8); Disposal/discharge device/sorting unit (8A); Encoder (8B);

Signal (8C) emitted by the encoder (8B); Food product (9); and Sliced/cut food product (9A).

DK 181541 B1 9

List of reference signs

This is a listing of various elements relating to the present invention.

Alternative/synonymous designations are separated by slashes: 1. The grading system of the invention 2. Rotatable cutting device/knife 3. Cutting device detector/photoelectric switch 3A. Detector signal 4. Trigger device/trigger 4A. Controlled trigger signal 5. Imaging means/camera 5A. Image transfer/signal 5B. Light trigger signal 6. Processing means/PC/controller 6A. Trigger signal 6B. Disposal device signal 7. Lighting means/light 8. Conveying means/conveyor belt 8A. Disposal/discharge device/sorting unit 8B. Encoder 8C. Signal emitted by the encoder (8B) 9. Food product 9A. Sliced/cut food product

Claims

DK 181541 B1 10 Patent claim

1. A system for classifying sliced food products, which classification system includes the following essential elements:

a. a rotatable cutting device (2) configured to slice a food product (9);

b. a cutting device detector (3) which is connected to a trigger device (4), which cutting device detector is configured to monitor the rotation of the rotatable cutting device (2) and to transmit the signal to the trigger device (4);

c. the triggering device (4) which is in communication with the cutting device detector (3) and optionally in communication with a process processing means (6), which triggering device is configured to delay the signal received from the cutting device detector (3);

d. an image recognition device (5) which is in communication with the release device (4) and with the process processing means (6), and optionally in communication with a light source (7), which image recognition device is configured to record one or more images of the food product (9 ), and to transmit the obtained data to the process processing means (6), and optionally configured to activate the light source (7) for illumination of the food product (9);

e. the process processing means (6) which is in communication with the triggering device (4) and with the image recognition device (5), which process processing means is configured to perform software calculations and/or to perform image analysis to perform the classification of sliced food products;

f. the light sources (7), which are possibly in connection with the image recognition device (5), and/or in connection with the processing means (6), which light sources are configured to illuminate the food product (9) at least during the image recording;

g. a conveyor (8), optionally in connection with the processing means (6), which conveyor is configured to receive and forward the sliced food product (9A); and which system is characterized in that the food product (9) is completely exposed during the recording of the one or more images by means of the image recognition device (5) for classifying the food product (9).

2. A method for classifying sliced food products using the system for classifying sliced food products, which system

DK 181541 B1 11 comprises a rotatable cutting device (2), a cutting device detector (3), a trigger device (4), an image recognition device (5), a process processing means (6), a light source (7) and a conveyor (8), and which procedure includes the following process steps:

i. providing the food product (9) to be classified and subjecting the food product (9) to analysis by means of the image recognition device (5), which image recognition device (5) is in communication and/or cooperation with the processing means (6), while the food product ( 9) is illuminated by means of the light source (7);

ii. slicing the supplied food product (9) using the rotatable cutting device (2) to obtain one or more sliced/sliced food products (9A) while the rotatable cutting device (2) is monitored by the slicing device detector (3) which is in communication with the trigger device (4) configured to delay the signal received from the cutting device detector (3);

iii. processing/analysis of data obtained in step i by the image recognition device (5) for classification of the food product in question (9) using the process processing means (6) which is in communication/cooperation with the image recognition device (5) and optionally with the triggering device (4); and iv. collecting the cut/sliced food product (9A) on the conveyor (8) to be taken for further processing on the production line, and identifying one or more cut/sliced food products (9A) to be disposed of at the disposal/discharge device (8A) ; which method is characterized in that the system for classifying the sliced food products, which includes the rotatable cutting device (2), the cutting device detector (3), the trigger device (4), the image recognition device (5), the processing means (6), the light source (7) and the conveyor (8), consists of the system according to claim 1.