Distributes award protocol: A cooperation and communication method for robots.

Abstract

In this Master’s Thesis a new Distributed Award Protocol (DAP) for robot communication and
cooperation is presented. Task assignment (contract awarding) is done dynamically with
contracts assigned to robots based upon the best bid received.
Instead of having a manager and a contractor it is proposed a fully distributed bidding/awarding
mechanism without a distinguished master. The best bidding robots are awarded with contract
for execution. The contractors make decisions locally. This brings the following benefits: no
communication bottleneck, low computational power requirement, increased robustness.
DAP can handle multitasking. Tasks can be injected into system during the execution of already
allocated tasks. As tasks have priorities, in the next cycle after taking into account actual bid
parameters of all robots, tasks can be re-allocated. The aim is to minimize a global cost function
which is a compromise between cost of task execution and cost of resources usage.
Information about tasks and bid values is spread among robots with the use of a Round Robin
Route, which is a novel solution proposed in this work. This method allows also identifying
failed robots. Such failed robot is eliminated from the list of awarded robots and its replacement
is found so the task is still executed by a team. If the failure of a robot was temporary (e.g.
communication noise) and the robot can recover, it can again participate in the next
bidding/awarding process.
Using a bidding/awarding mechanism allows robots to dynamically relocate among tasks. This is
also contributes to system robustness.
DAP was evaluated through multiple experiments done in the multi-robot simulation system. Various scenarios were tested to check the idea of the main algorithm. Different failures of robots (communication failures, partial hardware malfunctions) were simulated and observations were made regarding how DAP recovers from them. Also the DAP
flexibility to environment changes was watched. The experiments in the simulated environment confirmed the above features of DAP.