7,203 research outputs found
Networked PID control design : a pseudo-probabilistic robust approach
Networked Control Systems (NCS) are feedback/feed-forward control systems where control components (sensors, actuators and controllers) are distributed across a common communication network. In NCS, there exist network-induced random delays in each channel. This paper proposes a method to compensate the effects of these delays for the design and tuning of PID controllers. The control design is formulated as a constrained optimization problem and the controller stability and robustness criteria are incorporated as design constraints. The design is based on a polytopic description of the system using a Poisson pdf distribution of the delay. Simulation results are presented to demonstrate the performance of the proposed method
Efficient Transport Protocol for Networked Haptics Applications
The performance of haptic application is highly sensitive to communication delays and losses of data. It implies several constraints in developing networked haptic applications. This paper describes a new internet protocol called Efficient Transport Protocol (ETP), which aims at developing distributed interactive applications. TCP and UDP are transport protocols commonly used in any kind of networked communication, but they are not focused on real time application. This new protocol is focused on reducing roundtrip time (RTT) and inter packet gap (IPG). ETP is, therefore, optimized for interactive applications which are based on processes that are continuously exchanging data.ETP protocol is based on a state machine that decides the best strategies for optimizing RTT and IPG. Experiments have been carried out in order to compare this new protocol and UDP
Cooperative Adaptive Control for Cloud-Based Robotics
This paper studies collaboration through the cloud in the context of
cooperative adaptive control for robot manipulators. We first consider the case
of multiple robots manipulating a common object through synchronous centralized
update laws to identify unknown inertial parameters. Through this development,
we introduce a notion of Collective Sufficient Richness, wherein parameter
convergence can be enabled through teamwork in the group. The introduction of
this property and the analysis of stable adaptive controllers that benefit from
it constitute the main new contributions of this work. Building on this
original example, we then consider decentralized update laws, time-varying
network topologies, and the influence of communication delays on this process.
Perhaps surprisingly, these nonidealized networked conditions inherit the same
benefits of convergence being determined through collective effects for the
group. Simple simulations of a planar manipulator identifying an unknown load
are provided to illustrate the central idea and benefits of Collective
Sufficient Richness.Comment: ICRA 201
Time-and event-driven communication process for networked control systems: A survey
Copyright © 2014 Lei Zou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.In recent years, theoretical and practical research topics on networked control systems (NCSs) have gained an increasing interest from many researchers in a variety of disciplines owing to the extensive applications of NCSs in practice. In particular, an urgent need has arisen to understand the effects of communication processes on system performances. Sampling and protocol are two fundamental aspects of a communication process which have attracted a great deal of research attention. Most research focus has been on the analysis and control of dynamical behaviors under certain sampling procedures and communication protocols. In this paper, we aim to survey some recent advances on the analysis and synthesis issues of NCSs with different sampling procedures (time-and event-driven sampling) and protocols (static and dynamic protocols). First, these sampling procedures and protocols are introduced in detail according to their engineering backgrounds as well as dynamic natures. Then, the developments of the stabilization, control, and filtering problems are systematically reviewed and discussed in great detail. Finally, we conclude the paper by outlining future research challenges for analysis and synthesis problems of NCSs with different communication processes.This work was supported in part by the National Natural Science Foundation of China under Grants 61329301, 61374127, and 61374010, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany
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
Mathematical control of complex systems 2013
Mathematical control of complex systems have already become an ideal research area for control engineers, mathematicians, computer scientists, and biologists to understand, manage, analyze, and interpret functional information/dynamical behaviours from real-world complex dynamical systems, such as communication systems, process control, environmental systems, intelligent manufacturing systems, transportation systems, and structural systems. This special issue aims to bring together the latest/innovative knowledge and advances in mathematics for handling complex systems. Topics include, but are not limited to the following: control systems theory (behavioural systems, networked control systems, delay systems, distributed systems, infinite-dimensional systems, and positive systems); networked control (channel capacity constraints, control over communication networks, distributed filtering and control, information theory and control, and sensor networks); and stochastic systems (nonlinear filtering, nonparametric methods, particle filtering, partial identification, stochastic control, stochastic realization, system identification)
FMI Compliant Approach to Investigate the Impact of Communication to Islanded Microgrid Secondary Control
In multi-master islanded microgrids, the inverter controllers need to share
the signals and to coordinate, in either centralized or distributed way, in
order to operate properly and to assure a good functionality of the grid. The
central controller is used in centralized strategy. In distributed control,
Multi-agent system (MAS) is considered to be a suitable solution for
coordination of such system. However the latency and disturbance of the network
may disturb the communication from central controller to local controllers or
among agents or and negatively influence the grid operation. As a consequence,
communication aspects need to be properly addressed during the control design
and assessment. In this paper, we propose a holistic approach with
co-simulation using Functional Mockup Interface (FMI) standard to validate the
microgrid control system taking into account the communication network. A
use-case of islanded microgrid frequency secondary control with MAS under
consensus algorithm is implemented to demonstrate the impact of communication
and to illustrate the proposed holistic approach.Comment: Proceedings of the IEEE PES ISGT Asia 2017 conferenc
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