Distributed-Controlled Multiagent Mobile Platform with Digital Actuation Concept for Space Applications

Abstract

This paper describes an architecture for a multiagent robotic system that consists of a number of identical units. The homogeneous units are mechanically connected to construct a mobile platform named a “multiagent transportation (MAT) system.” Every unit has its local controller that communicates only with its adjacent units. This basic configuration of supervisorless structure affirmatively confines the dependence of each unit to a local area, and therefore any unit can be removed from or added into any part of a MAT system regardless of the timing and without disturbing the performance of the whole system. This flexibility of configuration significantly contributes to easy maintenance of units, such as battery charging or hot-replacing for faulty units. Utilizing this flexibility, MAT systems are able to adapt to a variety of tasks including transportation application and to target objects of various shapes and range of mass. These characteristics of MAT systems are the strong advantages for mobile robots, especially for ones activated in distant places, e.g., robotic planetary explorers. A proposed example unit of a MAT system shown in this paper employs a parallel link manipulator as its leg, and the digital-actuation (D-actuation) concept is applied for the local unit controller to actuate the leg. Together with the basic design of the example units, the controlling framework is described with simulation results to show the feasibility of the whole mobile system architecture.