A smart factory in a smart city: Virtual and augmented reality in a smart assembly line

Abstract

Increasingly, the smart city space is requiring a reconceptualization of forms and factors of production, including factories and their place in the smart city space. Factories have always been a part of the city and many people spend a significant part of their lives there. Cities and factories share the same physical space and draw from the same resources, such as the energy grid, communication networks, public utilities, social connections, etc. Factories and cities should share the same IoT network in order to maximize their synergy level. In this view, as ICT-enhanced solutions are being implemented and so the concept of the smart city becomes a reality, it is mandatory that the connection between the smart city and the smart factory is examined. This paper represents the first step in this direction. We are presenting a new smart way to lighten the workload for employees (especially those involved in assembly, setup and maintenance) and increase factory efficiency. We have developed a brand-new smart solution for designing and presenting work instructions. The solution can be easily adapted to use in other fields like healthcare or smart-homes. This paper presents a comparison of different types of virtual/augmented and conventional assembly instructions. Today, we face the challenge of a lack of skilled employees and a high rate of employee turnover. Both result in huge time and production losses, because new employees have to be taught simple assembly tasks over and over again. In addition, as companies begin hiring many more foreign workers who do not understand the local language, the challenge of teaching becomes even more acute. Despite this, in modern production systems we can still find ineffective and complicated books and manuals with assembly, service and measurement instructions. We have prepared several variants for non-trivial multi-step assembly instructions: traditional 'paper' instructions, video instructions, virtual instructions on screen (with/without in-situ projection and with/without a special controller). We have developed our own software system for working with and developing virtual assembly instructions. In this case the in-situ augmentation is a projection on to different parts of the workplace. 60 subjects were tested over two years in order to gather the learning curve for each of 5 types of instructions using virtual and augmented reality. We have proven that using any type other than 'paper' will shorten the learning time by approximately half. Practitioner summary: We have prepared and tested variants for non-trivial multi-step assembly instructions. 60 subjects were tested over two years in order to gather the learning curve for all 5 types of instructions - traditional paper, video instructions, virtual instructions and two types of virtual instructions combined with augmented reality in-situ projection. We have proven that using any type other than 'paper' will shorten the learning time by approximately half.