**Martin Juhás \* and Bohuslava Juhásová**

Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Trnava 917 24, Slovakia; bohuslava.juhasova@stuba.sk

**\*** Correspondence: martin\_juhas@stuba.sk

Received: 26 June 2020; Accepted: 23 July 2020; Published: 27 July 2020

**Abstract:** This paper presents a time-synchronization solution for operations performed by a heterogeneous set of robotic manipulators grouped into a production cell. The cell control is realized using master–slave architecture without an external control element. Information transmission in a cell is provided by a TCP/IP channel in which communication is ensured via sockets. The proposed problem solution includes an algorithm, which is verified and validated by simulation and tested in real environment. This algorithm requires minimal computational power thanks to an empirically oriented approach, which enables its processing directly by the control unit of each participating element of the robotic cell. The algorithm works on the basis of monitoring and evaluating time differences among sub-operations of master and slave devices. This ensures defined production cycle milestones of each robotic manipulator in the cell at the same time are attained. Dynamic speed adaptation of slave manipulators utilizing standard instructions of their native language is used. The proposed algorithm also includes a feedforward form of operations synchronization which responds to changes in the operating cycle of the master manipulator. The application of the solution proposal is supplemented with a visualization part. This part represents a complementary form of designed solution implementation.

**Keywords:** time-based synchronization; heterogeneous multi-robotic cell; socket communication; low computational power; native language application
