Mechatronics design of a robot society : a case study of minimalist underwater robots for distributed perception and task execution

Abstract

This thesis describes the mechatronics design of a cooperative multi-robot system, including systems level design, practical implementation, and testing. Two main subjects are integrated in this research work: the generic concept of a Robot Society as an engineering framework to control an autonomously operating distributed multi-robot system, and the constructed prototype society consisting of several sensor/actuator robots for submerged use in a liquid environment.

These novel types of prototype robots, SUBMARs, are targeted for distributed autonomous perception and task execution in the internal, three-dimensional on-line monitoring of various flow-through processes. The Robot Society control architecture implemented into SUBMAR robots supports such features as the autonomous cooperation of the robots, multi-tasking, self-organization, and selfoptimization in task execution. The mechatronics design of the robots has followed a minimalist approach, where the structure of the robot is maximally simplified. As a solution to compensate the obvious limitations derived from minimalism, the multiplicity and the cooperation of the robots have been exploited. On a systems level, this produces fault tolerant, flexible, and cost-effective engineering solutions for application.

Altogether over 90 logged experiment runs with physical robots have been completed to elucidate the functioning and reveal the factors affecting the performance of the system. The testing has been performed in a laboratory environment in a special demonstration process. In these experiment series, the searching and destroying of distributed dynamic targets were tested. Furthermore, the meaning of communication in the development of robot consciousness during the mission has also been analyzed.

As a result of the research work and systems development, profound knowledge has been gained and new solutions presented for the required technology for a minimalist mobile robot operating in a liquid process environment. SUBMAR Robot Society forms a technological basis for the development of real-world applications in the future.