50,767 research outputs found
On Conditional Decomposability
The requirement of a language to be conditionally decomposable is imposed on
a specification language in the coordination supervisory control framework of
discrete-event systems. In this paper, we present a polynomial-time algorithm
for the verification whether a language is conditionally decomposable with
respect to given alphabets. Moreover, we also present a polynomial-time
algorithm to extend the common alphabet so that the language becomes
conditionally decomposable. A relationship of conditional decomposability to
nonblockingness of modular discrete-event systems is also discussed in this
paper in the general settings. It is shown that conditional decomposability is
a weaker condition than nonblockingness.Comment: A few minor correction
Decentralized Hybrid Formation Control of Unmanned Aerial Vehicles
This paper presents a decentralized hybrid supervisory control approach for a
team of unmanned helicopters that are involved in a leader-follower formation
mission. Using a polar partitioning technique, the motion dynamics of the
follower helicopters are abstracted to finite state machines. Then, a discrete
supervisor is designed in a modular way for different components of the
formation mission including reaching the formation, keeping the formation, and
collision avoidance. Furthermore, a formal technique is developed to design the
local supervisors decentralizedly, so that the team of helicopters as whole,
can cooperatively accomplish a collision-free formation task
Supervisory Control Synthesis of Discrete-Event Systems using Coordination Scheme
Supervisory control of discrete-event systems with a global safety
specification and with only local supervisors is a difficult problem. For
global specifications the equivalent conditions for local control synthesis to
equal global control synthesis may not be met. This paper formulates and solves
a control synthesis problem for a generator with a global specification and
with a combination of a coordinator and local controllers. Conditional
controllability is proven to be an equivalent condition for the existence of
such a coordinated controller. A procedure to compute the least restrictive
solution is also provided in this paper and conditions are stated under which
the result of our procedure coincides with the supremal controllable
sublanguage.Comment: 29 pages, 11 figure
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