(Georgia Institute of Technology, 2011-12)
Kim, Jonghoek; Maxon, Sean; Egerstedt, Magnus B.; Zhang, Fumin
Intruder capturing games on a topological map of a workspace with obstacles are investigated. Assuming that a searcher can access the position of any intruder utilizing information networks, we provide theoretical upper bounds for the minimum number of searchers required to capture all intruders on a Voronoi graph. Intruder capturing algorithms are proposed and demonstrated through an online computer game.
(Georgia Institute of Technology, 2010-06)
Kim, Jonghoek; Zhang, Fumin; Egerstedt, Magnus B.
Consider a team of mobile agents monitoring large
areas, e.g. in the ocean or the atmosphere, with limited sensing
resources. Only the leader transmits information to other
agents, and the leader has a role to monitor battery levels
of all other agents. Every now and then, the leader commands
all other agents to move toward or away from the leader
with speeds proportional to their battery levels. The leader
then simultaneously estimates the battery levels of all other
agents from measurements of the relative distances between the
leader and other agents. We propose a nonlinear system model
that integrates a particle motion model and a dynamic battery
model that has demonstrated high accuracy in battery capacity
prediction. The extended Kalman filter (EKF) is applied to this
nonlinear model to estimate the battery level of each agent.
We improve the EKF so that, in addition to gain optimization
embedded in the EKF, the motions of agents are controlled to
minimize estimation error. Simulation results are presented to
demonstrate effectiveness of the proposed method.
(Georgia Institute of Technology, 2010)
Kim, Jonghoek; Zhang, Fumin; Egerstedt, Magnus B.
We present novel exploration algorithms and
a control law that enables the construction of Voronoi
diagrams over unknown areas using a single vehicle
equipped with range sensors. The control law uses range
measurements to make the vehicle track Voronoi edges
between obstacles. The exploration algorithms make
decisions at vertices in the Voronoi diagram to expand
the explored area until a complete Voronoi diagram is
constructed in finite time. Our exploration algorithms
are provably complete, and the convergence of the control
law is guaranteed. Simulations and experimental
results are provided to demonstrate the effectiveness of
both the control law and the exploration algorithms.