1,610 research outputs found
Towards a minimal order distributed observer for linear systems
In this paper we consider the distributed estimation problem for
continuous-time linear time-invariant (LTI) systems. A single linear plant is
observed by a network of local observers. Each local observer in the network
has access to only part of the output of the observed system, but can also
receive information on the state estimates of its neigbours. Each local
observer should in this way generate an estimate of the plant state. In this
paper we study the problem of existence of a reduced order distributed
observer. We show that if the observed system is observable and the network
graph is a strongly connected directed graph, then a distributed observer
exists with state space dimension equal to , where
is the number of network nodes, is the state space dimension of the
observed plant, and is the rank of the output matrix of the observed
output received by the th local observer. In the case of a single observer,
this result specializes to the well-known minimal order observer in classical
observer design.Comment: 12 pages, 1 figur
Detection and Mitigation of Biasing Attacks on Distributed Estimation Networks
The paper considers a problem of detecting and mitigating biasing attacks on
networks of state observers targeting cooperative state estimation algorithms.
The problem is cast within the recently developed framework of distributed
estimation utilizing the vector dissipativity approach. The paper shows that a
network of distributed observers can be endowed with an additional attack
detection layer capable of detecting biasing attacks and correcting their
effect on estimates produced by the network. An example is provided to
illustrate the performance of the proposed distributed attack detector.Comment: Accepted for publication in Automatic
A review of convex approaches for control, observation and safety of linear parameter varying and Takagi-Sugeno systems
This paper provides a review about the concept of convex systems based on Takagi-Sugeno, linear parameter varying (LPV) and quasi-LPV modeling. These paradigms are capable of hiding the nonlinearities by means of an equivalent description which uses a set of linear models interpolated by appropriately defined weighing functions. Convex systems have become very popular since they allow applying extended linear techniques based on linear matrix inequalities (LMIs) to complex nonlinear systems. This survey aims at providing the reader with a significant overview of the existing LMI-based techniques for convex systems in the fields of control, observation and safety. Firstly, a detailed review of stability, feedback, tracking and model predictive control (MPC) convex controllers is considered. Secondly, the problem of state estimation is addressed through the design of proportional, proportional-integral, unknown input and descriptor observers. Finally, safety of convex systems is discussed by describing popular techniques for fault diagnosis and fault tolerant control (FTC).Peer ReviewedPostprint (published version
A Framework on Fully Distributed State Estimation and Cooperative Stabilization of LTI Plants
How to realize high-level autonomy of individuals is one of key technical
issues to promote swarm intelligence of multi-agent (node) systems with
collective tasks, while the fully distributed design is a potential way to
achieve this goal. This paper works on the fully distributed state estimation
and cooperative stabilization problem of linear time-invariant (LTI) plants
with multiple nodes communicating over general directed graphs, and is aimed to
provide a fully distributed framework for each node to perform cooperative
stabilization tasks. First, by incorporating a novel adaptive law, a
consensus-based estimator is designed for each node to obtain the plant state
based on its local measurement and local interaction with neighbors, without
using any global information of the communication topology. Subsequently, a
local controller is developed for each node to stabilize the plant
collaboratively with performance guaranteed under mild conditions.
Specifically, the proposed method only requires that the communication graph be
strongly connected, and the plant be collectively controllable and observable.
Further, the proposed method can be applied to pure fully distributed state
estimation scenarios and modified for noise-bounded LTI plants. Finally, two
numerical examples are provided to show the effectiveness of the theoretical
results
Development of the PD/PI Extended State Observer to Detect Sensor and Actuator Faults Simultaneously
This paper discusses about an observer based faultdetection scheme to detect sensor and actuator faultssimultaneously in LTI system. The proposed strategy is to addderivative action on the extended state observer (ESO) in additionto proportional-integral action, so that the structure of theproposed observer is PD/PI or called PD/PI-ESO. The derivativeaction is performed both in state estimation and fault estimation.This is to achieve fast state estimation as well as fast faultestimation. Furthermore, the effects of disturbance are attenuatedby using the H performance approach. The observer gains arethen determined based on Linear Matrix Inequalities (LMI)technique. Simulation results of a DC motor speed control systemare presented to illustrate the effectiveness of the proposed method
Stabilization of Networked Control Systems with Sparse Observer-Controller Networks
In this paper we provide a set of stability conditions for linear
time-invariant networked control systems with arbitrary topology, using a
Lyapunov direct approach. We then use these stability conditions to provide a
novel low-complexity algorithm for the design of a sparse observer-based
control network. We employ distributed observers by employing the output of
other nodes to improve the stability of each observer dynamics. To avoid
unbounded growth of controller and observer gains, we impose bounds on their
norms. The effects of relaxation of these bounds is discussed when trying to
find the complete decentralization conditions
- …