Software VisionOkll: the artificial vision in the industrial state

The Centre of Vision by Computer (CVC) is a centre of non-profit investigation that founded in 1995 by the Government of Catalonia and the Autonomous University of Barcelona (UAB). His mission divides in two main aims. On the one hand, it devotes to the investigation in the field of the artificial vision, being centre of reference to European level. On the other hand, abiding by his have to of return of knowledge to the society, devotes a big effort to realizar projects of technological transfer and the learning of future researchers and technicians of high quality.

Inside the CVC can distinguish two very differentiated areas, a devoted to the investigation and another to the one of development. In the part of investigation, the doctorandos are formed in the field of the artificial vision by personal qualified researcher to the pair that realizar activities of teaching in the Máster of Vision by Computer and in the degree of it. The part of development is where realizar all the activity of technological transfer properly. In her, they resolve all the needs of the industry applying the know-how of the centre in fields so diverse like the hygiene, the production or the biomedicine. The usual procedure of the arrival of a project to the centre is by means of a diagnostic of previous feasibility. In this diagnostic, tries realizar a first approximation to the problem proposed to level of laboratory, analyse the possible complications that can present and estimates the corresponding budget to the execution of said project.

When working with vision by computer is of forced analysis achieve some conditions of optimum lighting to obtain an image the more nítida and contrasted possible. Of this way, in the moment to realizar the processed of the image purchased, the algorithms and technical to apply simplify in a high degree. By this, is necessary to know the different technical of lighting (diffuse, rasante, punctual, etc.), the effects of the no visible light in the different material (infrared and ultraviolet mainly) or the components of the light in surroundings no controlled, as it can be the solar light to know his impact on the images that are purchasing .

Image captured of a component of the car. The pines, in the top, and the lengüetas, in the inferior part, shine with regard to the bottom because of the diffuse lighting.

The vision by computer is a widely transversal technology, thus the projects of transfer cover several areas of knowledge inside the vision, between them, the industrial vision. To realizar these projects related with the control of quality, one of the tools of which has is a software designed and realizar by the CVC called VisionOkII.

Captures of the software VisionOkII. In this image shows the result after the processed previously parametrizado. In this case, the result has been Piece Nok, because of a defect of manufacture of one of the pines (square red).

This software allows the connection of one or several cameras, so much Firewire like Ethernet, and allows the access to his parameters to adjust them in function of the conditions of lighting, size of image, triggers necessary, etc. Besides, has of a series of controls already predefinidos to be able to realizar simple detections with algorithms highly optimised. This optimisation is key, since in a lot of occasions is necessary to give an answer with time of cycle very short. In the case to need some algorithms of higher complexity or very specific, is possible to expand the functionality designing algorithms to measures so that the final user can use them through the interficie like a control more.

Image captured where can see in the central part the different fuses with the recorded of the number and the colour that identifies them.

Once parametrizados so much the part of vision like the algorithms, already is possible to start the automatic execution that gives answer in each cycle, indicating if the piece has been properly manufactured or no and giving a signal or another like answer.

Incidentally, exist a series of complementary functionalities in VisionOkII that allow to manage the information or store data of interest. For this has of the possibility to save defective images or the record with the information of the process that is controlling .

The use of VisionOkII in the field of the industrial vision has allowed to realizar crowd of projects of industrial surroundings successfully. An example of this would be the control of quality that realizar to boxes of service of car for an important manufacturer of components of the sector. In this case, it was necessary to inspect the placing of the components in the circuit form, the weldings of these components, the glazed of the circuit form, the final setting of the box of services (components and connectors) and, finally, the marked end of the box of services (between other things, the impressesion of number of series).

Image of piece of car lit with light UV. The brilliant zones are owed to the effect of fluorescence produced by the lighting of this light on the varnish.

To analyse the placing of the components in the circuit form, inspected the measure and correct disposal of the lengüetas where would connect later the connectors and the correct position of the fuses inside said. Later, they analysed the weldings of all the components. In this point, it was necessary to take into account that the tin is an element that reflects a lot the light with what had to have very controlled the conditions of the surroundings not to obtain false positive and/or negative. For the correct glazed used an ultraviolet light since, because of the effect of fluorescence that produces, the zones covered by the varnish shined making possible detect if the glazed was properly executed. In the final setting detected witnesses it/absence of the previously determined components in a correct model, as well as the correct state of the different components (lengüetas straight, pines no bent, fuses in the position and with the correct value). Finally, in the marked end of the box, used an algorithm called 'Optical character recognition' (OCR), that allowed to recognise the different characters so that they could be identified and compared with the reading expected. Besides, it included the capacity of reading of codes in 1D and 2D since many times, by trazabilidad, is used to include this type of labeling.

Image of piece of car with text inscribed in his surface. It contains all the necessary information to identify to the piece and obtain his trazabilidad. This text has to be read by means of an algorithm called 'Optical character recognition' (OCR).

Thanks to the software designed in the CVC, VisionOkII, have been able to develop big part of the projects of industrial vision. This software is a very complete tool, versatile and customizable that contains a series of simple controls to realizar a control of basic quality but that allows to include specific algorithms for cases very concrete where sue some more advanced controls.