176 research outputs found
Decentralized event-triggered control over wireless sensor/actuator networks
In recent years we have witnessed a move of the major industrial automation
providers into the wireless domain. While most of these companies already offer
wireless products for measurement and monitoring purposes, the ultimate goal is
to be able to close feedback loops over wireless networks interconnecting
sensors, computation devices, and actuators. In this paper we present a
decentralized event-triggered implementation, over sensor/actuator networks, of
centralized nonlinear controllers. Event-triggered control has been recently
proposed as an alternative to the more traditional periodic execution of
control tasks. In a typical event-triggered implementation, the control signals
are kept constant until the violation of a condition on the state of the plant
triggers the re-computation of the control signals. The possibility of reducing
the number of re-computations, and thus of transmissions, while guaranteeing
desired levels of performance makes event-triggered control very appealing in
the context of sensor/actuator networks. In these systems the communication
network is a shared resource and event-triggered implementations of control
laws offer a flexible way to reduce network utilization. Moreover reducing the
number of times that a feedback control law is executed implies a reduction in
transmissions and thus a reduction in energy expenditures of battery powered
wireless sensor nodes.Comment: 13 pages, 3 figures, journal submissio
Isochronous Partitions for Region-Based Self-Triggered Control
In this work, we propose a region-based self-triggered control (STC) scheme
for nonlinear systems. The state space is partitioned into a finite number of
regions, each of which is associated to a uniform inter-event time. The
controller, at each sampling time instant, checks to which region does the
current state belong, and correspondingly decides the next sampling time
instant. To derive the regions along with their corresponding inter-event
times, we use approximations of isochronous manifolds, a notion firstly
introduced in [1]. This work addresses some theoretical issues of [1] and
proposes an effective computational approach that generates approximations of
isochronous manifolds, thus enabling the region-based STC scheme. The
efficiency of both our theoretical results and the proposed algorithm are
demonstrated through simulation examples
Symbolic models for nonlinear control systems without stability assumptions
Finite-state models of control systems were proposed by several researchers
as a convenient mechanism to synthesize controllers enforcing complex
specifications. Most techniques for the construction of such symbolic models
have two main drawbacks: either they can only be applied to restrictive classes
of systems, or they require the exact computation of reachable sets. In this
paper, we propose a new abstraction technique that is applicable to any smooth
control system as long as we are only interested in its behavior in a compact
set. Moreover, the exact computation of reachable sets is not required. The
effectiveness of the proposed results is illustrated by synthesizing a
controller to steer a vehicle.Comment: 11 pages, 2 figures, journa
- …