Optimization of tasks scheduling in cooperative robotics manufacturing via johnson's algorithm case-study: One collaborative robot in cooperation with two workers

The rapid development of information technology in the last half century led to the emergence of a new industrial revolution, often called Industry 4.0, the key element of which is the introduction of informatization in all spheres of human life and the widespread use of cyberphysical systems. The main attribute of such systems is the interaction of human and smart machines, this approach allows achieving the greatest flexibility and productivity simultaneously. The latest example of such systems is the collaborative manufacturing system, where the human worker cooperates in a close distance with a collaborative robot (cobot) in a production scenario. This cooperation is applicable when the final product requires a high degree of customization that a worker can provide, while cooperation with the cobot is greatly speeding up the productivity. In this context, one of the actual problems is to schedule the cooperative tasks in real time among the operational resources (i.e., the workers and cobots). This problem can be reduced to a special case of the flow-shop scheduling problem. The complexity of this problem increases with increasing the number of cooperative operational resources and the production steps. Undoubtedly, modern production often involves several processing steps serviced by several operational resources. Therefore, it is necessary to study a complex cooperative manufacturing scenario. The simplest and most understandable case scenario is the interaction of two workers and one cobot in two stages production workcell. Thus, in this paper we will consider the implementation of this case-study using the available scheduling algorithms.