GrapeSort Optical Sorter


GrapeSort Optical Sorter
GrapeSort Optical Sorter - History
Under a *ZIM project funded by the German Federal Ministry for Economic Affairs and Energy, Armbruster Kelterei-Technologie GmbH in cooperation with Geisenheim University of Applied Sciences and Fraunhofer Institute IOSB in Karlsruhe has developed an optical sorting system aimed at modifying the optical components and image analysis so that in addition to segregating foreign matter sorting could be achieved according to various maturity criteria.
The objective of the development project was to enhance the diversity of aromas present in the various quality grades of wine by means of a specific selection of the grapes according to various quality-related criteria such as grape must density on the Oechsle Scale, nitrogen content, acid, rot as well as whole or damaged grapes, mash and must quality by removing undesirable MOG (material other than grapes). Product protection during grape processing was to be optimized. A smooth surface was to ensure steadying of the material during conveyance on the belt. Cleaning of the sorter was to be adjusted to requirements, and thus be made easier compared with existing systems. Intuitive software operation allowing even non-experts to achieve outstanding sorting qualities was an additional requirement.
Initial preliminary tests revealed that image acquisition using light within the visible range is capable of detecting differences in the maturity level of grapes. The combination with light in the near-infrared range (NIR) is another approach in this direction. Spectral investigations to identify relevant wavelength ranges serving as the basis for the development of the opto-electrical sorter are used to optimize quality-dependent sorting. Pictures in the visible and NIR ranges were taken by Fraunhofer Institute IOSB and analyzed using multivariate methods. In an interaction with the analyses and laboratory activities of the Geisenheim Research Institute, correlations between wavelengths and quality parameters were developed with the aim of adjusting the optical components and image analysis.
Project Tasks
IOSB Fraunhofer Institute
Scientific work on image acquisition and image processing of the optical sorting system was performed by the academic staff of Fraunhaufer Institute for Optronics, System Technology and Image Exploitation (IOSB), Karlsruhe.    
Geisenheim University of Applied Sciences
Geisenheim University of Applied Sciences assumed responsibility for gathering quality-related data of grapes during the course of their maturing process in order to correlate optical, physical and analytical data, and to work out correlations between quality parameters and wavelengths in interaction with image data gathered by Fraunhofer Institute IOSB.
Armbruster Kelterei-Technologie GmbH
Armbruster Kelterei-Technologie GmbH assumed responsibility for developing and creating the optical sorting system, focused on mechanical selection according to various maturity parameters, reduction of air entry and juice atomization, steadied material feeding, singling of the grapes after destemming, accelerating them to approx. 3 m/sec and effectively feeding the grapes to the optical sorting unit without intrinsic motion on the conveyor belt. Cleaning of the sorting system and user-friendly quality control by enhanced operating concepts were other key objectives.
Due to the findings obtained in the tests run in fall of the preceding years, the GrapeSort optical sorting system has been developed to production level and put into practice in California this year. A separation according to maturity parameters was deliberately omitted and the main focus put on separating MOG (material other than grapes). Never before has an equally high level of precision in MOG separation been achieved. The high-resolution 4-channel-camera RGB+NIR precisely detects flaws, such as the early stage of dried-up grapes. Lighting with tailored LED lamps (alternating white LEDs and infrared LEDs) and purpose-developed software by Fraunhofer Institute IOSB meets the high market demands made on product quality and safety, providing the ultimate sorting solution for maximum quality in grape processing. Easy access due to the open design of the housing and belt removal from the conveyor belt with pneumatic quick-release facilitates and accelerates cleaning and maintenance. 
Armbruster Kelterei-Technologie GmbH
74363 Güglingen
October 2016