The aim of the project is the user-optimal supply of information using data glasses to be carried by the order picker, which displays all relevant data for the correct execution of the picking task depending on place, time, field of view and the status of the order. The novel picking system shall enable intuitive and freehand work, adjusted optimally to the user concerning ergonomic and labor scientific aspects, have a simple communication interface to enter data by the order picker, be easy to learn its application and fulfill the demands in an industrial environment.
Augmented reality (AR) is a sub-area of virtual reality. AR is the superimposition resp. extension of human perception by computer-generated virtual information. In most cases, only the visual sense is addressed, as the user is supplied with information in context in his field of vision i.e. at the right time at the right place. The real and virtual world are combined in such a way that the user interprets the newly created three-dimensional environment as a unit and can interact with it in real-time. The virtual objects serve as additional information not perceptible by human senses, so that the user can better conduct his real work task.
The AR technology offers a multitude of fields of application ranging from military applications, medical technology or architecture to industry e.g. quality management, construction of prototypes, service and maintenance or assembly. In logistics there are also interesting fields of application. One of them is picking.
At the beginning of the project, possible application scenarios and effects on the picking process as well as the resulting demands of an augmented reality supported commission system were systematically worked out. Pick-by-vision is especially suitable for conventional picking systems according to the man-to goods principle, but also for the picking along a row shelf or at stationary picking workplaces. The picking process as such does not change in contrast to other voucherless picking systems. After these basic investigations the selection of the most important hardware and software components is conducted. In the case of the data glasses, the decisive man-machine interface for user acceptance, a monocular virtual retinal display which projects the picture with a weak laser directly onto the retina proved to be the best solution. Language control or a turning button or one to press are used as interactive devices. A tracking system is necessary which records the position and the looking direction of the user, so that the virtual information is displayed in the correct position in space. For the application in picking optical procedures, which can possibly combined with an intertialtracker, are especially suitable. Concerning software a warehouse management system and AR software of the project partners are used.
After the selection of the suitable hardware and software components, a user interface is designed especially for the selected cases of application. This can be understood as the depiction using data glasses and the quantity of the information presented to the order picker and the interactive possibilities of the user with the system e.g. for the acknowledgement of taking out an article. Together with CIM GmbH, a first function model without the use of a tracking system was developed using these results. Thereby information is only presented in text form. The interaction occurs by voice input. For man language is the most natural form of passing on information and he or she has both hands free for the actual task. This first function pattern was repeatedly evaluated and optimized iteratively. The evaluations were conducted in the experimental hall of the chair fml and a distribution center of Kühne+Nagel (AG & Co.)KG. Using an MTM analysis, a theoretical observation of the pick-by-vision system compared to a paper list and a pick-by-voice system was conducted. Together with the subject area for augmented reality (FAR) of the TU of Munich, a second function pattern was implemented using an optical tracking system and with a turning button and button to push. In several pre-investigations in the laboratory, different virtual 3D geometries for finding the way and to support the grabbing motion were tested. After the porting of the system into the experimental hall of the chair fml, again there was an evaluation with a subject program.
In the series of experiments both function patterns showed potential to improve the picking. Especially the picking error rate was reduced by a strict leading of the process and the blending in of data into the field of view of the user. If virtual geometries directly highlight the storage area the mental effort is slight and the error rate is low, as no description of the storage area in text form must be transported from the medium supplying information to the real environment. Compared with a paper list but also a simple pick-by-voice-system, the picking times were slightly lower. The reason for this was that the paper list was not handled and there was no sequential give-out of the information. The difference is not significant, but in the case of pick-by-voice, there is a very steep learning curve. Aside from the logistical key figures, the subjective strain of the subjects was determined. The subjects hardly uttered any complaints, liked to work with pick-by-vision in a motivated way. All series of experiments only encompassed a short wearing of the data glasses, so that further and longer ongoing investigations are necessary.
Günthner, W. A., Blomeyer, N., Reif, R., Schedlbauer, M.:
Pick-by-Vision: Augmented Reality unterstützte Kommissionierung
(Pick-by-vision: Picking supported by augmented reality)
Final report, Research project (AiF-FV-Nr. 14756 N) was funded from resources of the Federal Ministry for economics and via the work committee of industrial research association ""Otto von Guericke"" e.V. (AiF) , February 2009
Technical University of Munich
In cooperation with the subject area for augmented reality of the TUM.