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Prosjektnummer

901246

Prosjektinformasjon

Prosjektnummer: 901246
Status: Avsluttet
Startdato: 01.08.2016
Sluttdato: 14.04.2017

Automatic quality control of internal defects in codfish fillets (QCod)

• Deteksjonsraten med det nye hyperspektrale oppsettet var på 40 %, noe som er mindre enn rapportert i tidligere studier.
• Dual-energy CT var i stand til å påvise dyptliggende kveis, men metoden er for tidskrevende og for dyr for industriell anvendelse.
• Målinger utført med vanlig dual-energy røntgen ga ingen endelige svar og krever nærmere studier.
• Hovedkonklusjonen er at det er nødvendig med videre forskning og utvikling på deteksjonsteknikkene før de kan implementeres i industrielle prototyper.

Results achieved
Summary of results from the project's final reporting

The main purpose of the project was to develop methods for detection of embedded quality faults in whitefish fillets, such as nematodes. Previous studies had shown interactance hyperspectral imaging to be a promising method to identify nematodes in cod fillets automatically. After modification of the illumination setup, trials were carried out where the detection and false positive rates were studied. Other approaches tested were ultrasound, x-ray imaging and NIR laser transmittance imaging. All technologies were compared in a joint test at the end of the project.

The detection rate with the new hyperspectral setup was approximately 40 %, less than the previous study. This is attributed to the storage time of the fillets compared to the previous work and differences in sample handling between the training and test set. Future work would need to be performed on-site to avoid results more pessimistic than would be encountered in industrial implementation. The ultrasound images were noisy and produced too little contrast between the muscle and nematodes, making reliable detection not feasible. Dual-energy ray CT proved capable of detecting deeply buried nematodes but is too slow and expensive for industrial application. Measurements on planar xray were inconclusive and require further study. While some high-density spots were observed in the loin in locations where nematodes were located during dissection, not all nematodes were identified and contrast was low.

Consequently, further research and development of the detection methods is needed before implementation in industrial prototypes.

Sammendrag av resultater fra prosjektets faglige rapportering
Hovedhensikten med prosjektet var å utvikle metoder for deteksjon av innvendig kvalitetsfeil i hvitfiskfileter, som for eksempel kveis. Tidligere studier hadde vist at hyperspektral avbildning i interaktansmodus var en lovende metode for automatisk påvisning av kveis i torskemuskel. Etter å ha modifisert på belysningsoppsettet ble forsøk gjennomført hvor deteksjonsrate og falsk positiv rate ble vurdert. Andre tilnærminger som ble testet var ultralyd, røntgen og NIR (nær-infrarød)-laser avbildning. Alle teknologiene ble sammenlignet i en felles test på slutten av prosjektet.

Deteksjonsraten med det nye hyperspektrale oppsettet var på 40 %, noe som er mindre enn rapportert i tidligere studier. Dette skyldes at i tidligere studier ble fisken målt i industrien rett etter filetering, men i dette arbeidet ble fisken målt etter varierende lagringstid som filet. I fremtidig arbeid må forsøkene kjøres i industrien for å få frem det reelle potensialet for metodene.
 
Ultralydbildene ble støyete og ga liten kontrast mellom muskel og kveis slik at pålitelig deteksjon av kveis ikke var mulig. Derimot var dual-energy CT (computertomografi) i stand til å påvise dyptliggende kveis, men metoden er for tidskrevende og for dyr for industriell anvendelse. Målinger utført med vanlig dual-energy røntgen ga ingen endelige konklusjoner og krever nærmere studier. Selv om noen høyintensitets flekker ble observert i områder hvor manuell inspeksjon påviste kveis ble ikke alle kveis påvist og kontrasten var lav. Dermed er konklusjonen at videre forskning og utvikling på deteksjonsteknikkene er nødvendig før de kan implementeres i industrielle prototyper.
Prosjektet konkluderte med at det er nødvendig med videre FoU-arbeid før de undersøkte deteksjonsteknikkene kan utvikles til kommersiell teknologi. Automatisk kvalitetskontroll av både filet og rund fisk er imidlertid svært viktig for å sikre automatisert og effektiv produksjon av hvitfisk. FHF har derfor gjennom en strategisk satsing for fullautomatisert råstoffhåndtering og filetproduksjon i hvitfisknæringen utlyst inntil 12 mill. kr gjennom FHFs “Prosjekt i bedrift (PIB)​”-ordning i november 2017. Utlysningen legger vekt på 3 områder, der det ene området er automatisk kvalitetskontroll av rund fisk og filet.
Background
Rationale for project execution
Automation of fish processing has been recognized as a key factor in maintaining a strong and competitive fish processing industry within the Nordic countries. Approaches for in-line monitoring of quality of raw material and products are needed to improve production management and optimize throughput and value of products. 
 
Over the last years, there has been an increase in volume of fresh fish products entering the market. This has enhanced the need for detection of internal defects in fillets, such as nematodes. The products must now meet stricter requirements of the market, and failure to meet these can have dramatic effects on publicity and market position of wild whitefish products.
 
Problem description
Quality grading and inspections is yet done manually, and therefore depend on employee skills and performance each day. Manual evaluation is typically based on sampling whereas automated quality systems can verify every product. Automated methods can be calibrated and standardized meanwhile there is always a risk of human errors and differences between individual employees in manual inspection. Reducing human error with automated quality control systems also allows companies to focus their human resources on areas of the operation where they can be better utilized.
 
Among the challenges associated with automated in-line quality grading systems are the high inspection speed needed, detection of defects buried or embedded deep in the fish muscle, varying thickness and size of fillets, whether products are skinned or not, the harsh processing environment and price limits for the measurement equipment needed. 
 
Relevance to NSRFs annual priorities
The main purpose of the research activities described in this proposal is to develop methods for detection of embedded nematodes, blood spots and bones in whitefish fillets. The quality measurement methods developed in the proposed project will be combined with the methods from the ongoing project in a future automatic quality inspection prototype.
Objectives
Purpose of project
To develop an inspection prototype for identifying embedded quality defects in whitefish.

The main sub-objectives are:
• To evaluate three measurement techniques with potential for measuring internal defects, hyperspectral imaging, ultrasound and Near Infra Red (NIR) laser transmission.
• To design and construct lab prototypes for preliminary testing.
• To select the optimal measurement technique and produce a design for the industrial prototype, keeping in mind cost and ease of implementation (in the fish processing industry).
 
Problem to be solved
The anticipated results of the project will show whether it is possible to simplify (lower the cost) and improve the performance for the hyperspectral imaging system with respect to detection of nematodes and blood in whitefish.
 
Furthermore it will be evaluated whether ultrasound and NIR laser transmittance imaging can be applied as alternative methods that are capable of nematode and bone fragments detection with a similar detection performance as hyperspectral imaging but at a lower cost.
Expected project impact
The markets are getting stricter when it comes to occurrence of nematodes within the products, particularly in fresh products. Failures in meeting market requirements can have dramatic effects on market position and prices for wild whitefish products. Inspection systems that can detect the nematodes and other embedded defects such as blood are essential to secure that quality requirements are met and that companies will have access to high paying markets.
 
Automated quality systems that monitor each product will also improve traceability in the production and tracking to raw material. Data on quality attributes can be used by producer to related value and condition of raw material with its origin and become a tool in trading with the fishing industry.
 
Rapid, reliable detection methods with a sufficient detection rate for deeply embedded defects are a prerequisite for automating quality inspection. The scientific knowledge within Nofima and SINTEF in this field is essential for developing measurement technology that can be transferred and integrated in industrial solutions.
 
How the results will contribute to Health and Safety Environment (HSE) in the company
Material and design for the industrial prototype will be selected with respect to full-scale commercial operation, and requirements for HSE and hygiene.
 
Environmental effect of results
Quality grading and sorting systems for fish will support sustainable utilization of natural resources, such as wild whitefish catch.
 
Expected impact on product qualities
More standardized production, risk related to defects minimized by the anticipated outcome of the project.
 
Expected impact on production capacity
The production capacity on the trimming line is assumed to increase, as automatic systems will replace manual inspection for quality deviations. Also, the advantage of automated system is that every piece will be inspected instead of specific samples per lot.
Project design and implementation
The project work will involve a study on the feasibility of different detection solutions that are potential for commercialization. The focus will be on detection of embedded defects (nematodes, blood and bones) in whitefish fillets. Among deliverables will be lab prototypes and specifications for different inspection technologies and description of criteria for selecting the system to use in an industrial prototype.

The execution of the project is divided into following workpackages (WPs):
 
WP 1.1. Concept development and specifications for automated inspection system
The goal is to define the industrial requirements in relation to following parameters and define specifications for detection of nematodes, blood and bones.
 
WP 1.2. Improve interactance hyperspectral imaging for detection of nematodes and blood
The purpose is to improve illumination, identify optimum detection wavelengths, and develop algorithms for nematode detection.
 
WP 1.3. A feasibility study on ultrasound for nematode and bones
Experimental setup using ultrasonic imager, will be tested to evaluate ultrasound for detecting nematodes and bones in fish fillets.
 
WP 1.4. A feasibility study on NIR laser transmittance imaging for nematode and bones
The aim is to design an experimental set-up for testing the performance of different lasers for detecting nematodes and bones.
 
WP 1.5. Joint testing and evaluation of methods
At the end of the project, the systems developed will be compared and evaluated in a joint test.
 
WP 1.6. Design plan and project description for prototyping
This workpackage includes a decision point, where results from WP. 1.5. will be used to determine whether the detection technology is ready for prototyping. The results will be used to decide whether to continue the work and go for industrial prototyping (in an additional project).
Dissemination of project results
Results will be communicated at NSRF workshops and at meetings with the seafood industry. Results from research activities of hyperspectral imaging, ultrasound and Near Infra Red laser transmittance imaging will be presented in scientific media.
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