Abstract-The study of human control of robotic swarms involves designing interfaces and algorithms for allowing a human operator to influence a swarm of robots. One of the main difficulties, however, is determining how to most effectively influence the swarm after it has been deployed. This may be necessary in a environmental exploration task where areas of interest arise dynamically, and thus the human operator needs to guide the swarm to explore them. Past work has focused on influencing the swarm via statically selected leaders-swarm members that the operator directly controls. These leaders have been pre-selected and remain leaders throughout the scenario execution. This paper investigates the use of a small subset of the swarm as robot leaders that are dynamically selected during the scenario execution and are directly controlled by the human operator to guide the rest of the swarm, which is operating under a flocking-style algorithm. The goal of the operator in this study is to move the swarm to goal regions that arise dynamically in the environment. We experimentally investigated (a) the effect of density of leaders on the ease of human control and system performance, and (b) how restriction of information communicated to the human operator affects the ability to guide the swarm to goal regions. The density of leaders is computed based on an extension of the RCC algorithm used in wireless sensor networks to select cluster heads. We used a "hop guarantee" in this leader selection algorithm as a measure of leader density. A n-hop guarantee means that every robot is at most n-hops away from a leader. In particular, we studied the effect of 1-hop, 2-hop and 3-hop guarantee on the swarm performance. Our results show that, while there was a large drop in the number of goals reached when moving from a 1-hop to a 2-hop guarantee, the difference between a 2-hop and 3-hop guarantee was not statistically significant. Furthermore, we found that performance was just as good when the information returned to the operator was restricted, showing that operators can still navigate a swarm even when they have imperfect information.

Abstract-As swarms are used in increasingly more complex scenarios, further investigation is needed to determine how to give human operators the best tools to properly influence the swarm after deployment. Previous research has focused on relaying influence from the operator to the swarm, either by broadcasting commands to the entire swarm or by influencing the swarm through the teleoperation of a leader. While these methods each have their different applications, there has been a lack of research into how the influence should be propagated through the swarm in leader-based methods. This paper focuses on two simple methods of information propagation-flooding and consensus-and compares the ability of operators to maneuver the swarm to goal points using each, both with and without sensing error. Flooding involves each robot explicitly matching the speed and direction of the leader (or matching the speed and direction of the first neighboring robot that has already done so), and consensus involves each robot matching the average speed and direction of all the neighbors it senses. We discover that the flooding method is significantly more effective, yet the consensus method has some advantages at lower speeds, and in terms of overall connectivity and cohesion of the swarm.

Abstract-The study of human control of robotic swarms involves designing interfaces and algorithms for allowing a human operator to influence a swarm of robots. One of the main difficulties, however, is determining how to most effectively influence the swarm after it has been deployed. Past work has focused on influencing the swarm via statically selected leaders-swarm members that the operator directly controls. This paper investigates the use of a small subset of the swarm as leaders that are dynamically selected during the scenario execution and are directly controlled by the human operator to guide the rest of the swarm, which is operating under a flocking-style algorithm. The goal of the operator in this study is to move the swarm to goal regions that arise dynamically in the environment. We experimentally investigated three different aspects of dynamic leader-based swarm control and their interactions: leader density (in terms of guaranteed hops to a leader), sensing error, and method of information propagation from leaders to the rest of the swarm. Our results show that, while there was a large drop in the number of goals reached when moving from a 1-hop to a 2-hop guarantee, the difference between a 2-hop, 3-hop, and 4-hop guarantee was not statistically significant. Furthermore, we found that sensing error impacted the flooding information-propagation method more than the consensus method conditions, and caused participants more trouble the lower the density of leaders.

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