# Synchronization of Heterogeneous Multi-Robotic Cell with Emphasis on Low Computing Power
## 1 Introduction
The work of [PERSON] and [PERSON] [13] presents a new synchronization tracking control law that can be directly applied to the cooperative control of multi-robot systems and oscillation synchronization in robotic manipulation and locomotion, where a common desired trajectory can be explicitly given. [PERSON] et al. [14] describe a controller utilization that solves the problem of position synchronization of two (or more) robotic systems, under a cooperative scheme, in the case when only position measurements are available. In the work of [PERSON] [15], a Petri-net-based prototyping tool is presented to implement the control flow of parallel processes in multiple robot systems. The next variant of synchronization is presented by [PERSON] et al. [16], where the coordination control of two flexible joint robotic manipulators using flat outputs is implemented by means of simulations. The differential flatness technique of trajectory generation enables easy estimation of synchronization parameters and trivializes stabilization of these trajectories around predefined points. [PERSON] et al. [17] describe a new adaptive algorithm, which was proposed for synchronization and trajectory tracking of multiple robot manipulators. The same authors also discuss other techniques in this problem area. They describe the possibility of designing decentralized control laws to cooperatively command a team of general actuated manipulators in the article \"Distributed synchronization control to trajectory tracking of multiple robot manipulators\" [18], or an approach to position synchronization of multiple robot manipulators based on emergent consensus algorithms [19]. Synchronization of activities in task-oriented robotic rehabilitation training using iterative learning synchronization (ILS) and immediate error correction (IEC) techniques is addressed by [PERSON] et al. [20]. In the above-mentioned cases, the authors based their solutions on complex mathematical algorithms and derivation of complex relations, or by exploring new approaches using specialized hardware. These methods require investment in hardware infrastructure, which is their major disadvantage. In some cases in homogenous production complexes, it is possible to use tools that are directly implemented in control systems, such as the MultiMove option of ABB robots [21; 22] or the RoboTeam software of KUKA [22; 23]. However, if limited possibilities exist to upgrade infrastructure and it is desired to use available hardware that may not be from the latest production series, there could be a serious problem with the use of the previously described solutions. We used an alternative approach in a production or technical process of a simple solution implementation even in production facilities without the possibility of using sophisticated methods of robotic set or robotic cell synchronization. Our aim is the simplest solution possible in terms of computing power demands. The basis is to design the least complex algorithms that can be easily implemented in existing controllers in their native programming languages. Therefore, our goal is to develop a solution in which synchronization algorithms can be performed directly on the control units of robotic manipulators. This is based on the utilization of our rich empirical knowledge and experiences in algorithms, in addition to the implementation of various tasks in the field of robotics or modeling and visualization of processes. The main idea does not lead to a specific use or solution to a precisely specified problem, for example in a production process. The aim of the proposed solution can have a wide range. From the analyzed areas it is possible to use this solution either in production or in healthcare in rehabilitation. Another area of application could be the control of collaboration-oriented workplaces with a master manipulator connected to movements of a human as a cell control element. Finally, it could be used in presentation events oriented to Industry 4.0 or the latest trend, Internet-of-Robotic-Things (IoRT).