50 research outputs found
Control of one-dimensional guided formations using coarse information
Motivated by applications in intelligent highway systems, the paper studies
the problem of guiding mobile agents in a one-dimensional formation to their
desired relative positions. Only coarse information is used which is
communicated from a guidance system that monitors in real time the agents'
motions. The desired relative positions are defined by the given distance
constraints between the agents under which the overall formation is rigid in
shape and thus admits locally a unique realization. It is shown that even when
the guidance system can only transmit at most four bits of information to each
agent, it is still possible to design control laws to guide the agents to their
desired positions. We further delineate the thin set of initial conditions for
which the proposed control law may fail using the example of a three-agent
formation. Tools from non-smooth analysis are utilized for the convergence
analysis.Comment: 13 pages, 4 figure
A power consensus algorithm for DC microgrids
A novel power consensus algorithm for DC microgrids is proposed and analyzed.
DC microgrids are networks composed of DC sources, loads, and interconnecting
lines. They are represented by differential-algebraic equations connected over
an undirected weighted graph that models the electrical circuit. A second graph
represents the communication network over which the source nodes exchange
information about the instantaneous powers, which is used to adjust the
injected current accordingly. This give rise to a nonlinear consensus-like
system of differential-algebraic equations that is analyzed via Lyapunov
functions inspired by the physics of the system. We establish convergence to
the set of equilibria consisting of weighted consensus power vectors as well as
preservation of the weighted geometric mean of the source voltages. The results
apply to networks with constant impedance, constant current and constant power
loads.Comment: Abridged version submitted to the 20th IFAC World Congress, Toulouse,
Franc