Method of information interaction for distributed control systems of robots with modular architecture

The paper presents a solution to the problem of information interaction between embedded computing devices in the implementation of distributed control in the information-measuring and control system (IMCS) of robots with modular architecture. Distributed control is realized by designing each module as a device with its own IMCS containing all the components necessary to perform its functionality, including computing devices. As a consequence of such a functional completion of the modules, the computations needed to control the robot as a single mechatronic system are parallelized. As a result, the requirements to the power of computing devices of modules’ IMCS are significantly reduced, as it is possible to use inexpensive microcontrollers and single-board computers – embedded computing devices.
The network organization of the IMCS structure of the robot is proposed, which allowed the transfer of the reconfigurability property of the network to the structure of the modular robot. Analysis of various network topologies has shown that the topology of the "star" type has several advantages over the topology of the "bus" type for use in heterogeneous modular robots.
It is shown that the use of the Robot Operating System (ROS) for the implementation of information interaction between embedded computing devices is either impossible or significantly hampered. A specification is proposed for the creation of appropriate programming interfaces and a language for inter-module communication, which enable the inclusion of third-party modules in the plug and play mode. The specification is based on the principles of ROS, but allows one to implement software on embedded computing devices. On the basis of Pareto's multi-criteria optimization, recommendations were obtained for selecting the appropriate hardware and software.
The efficiency of the proposed solution was proved in the course of experiments on an installation whose composition is close to the working conditions of the IMCS of a heterogeneous modular robot. The experiments showed that the joint operation of the software and hardware parts meets all the specified requirements and is applicable for the transmission of messages of the executive level with a frequency of up to 100 Hz under any load on the network.