In Networked Control Systems (NCS), data networks not only limit the amount of information exchanged by system components but are also subject to stochastic packet delays and losses. In this paper, we present a controller that simultaneously addresses these problems by combining event-based and sequence-based control methods. At every time step, the proposed controller calculates a sequence of ...

In networked control systems, time delay and data dropout can degrade the performance of the control system and even destabilize the system. In the present paper, the Extended Kalman filter is employed to compensate the effects of time delay and data dropout in feedforward and feedback paths of networked control systems. In the proposed method, the extended Kalman filter is used as an observer ...

Abstract: In this paper, we develop a co-design methodology of stochastic optimal controllers and network parameters that optimizes the overall quality of control (QoC) in networked control systems (NCSs). A new dynamic model for NCSs is provided. The relationship between the system stability and performance and the sampling frequency is investigated, and the analysis of co-design of control an...

This work presents a method to estimate an unknown varying delay of measurements and subsequent Kalman filtering in the networked control system (NCS) framework. The delay estimation algorithm is based on the Gaussian error model and a network delay model, either a probability distribution or a Markov-chain. This method is used to tackle the problem with varying delays in a NCS. The undelayed o...

The issues of stochastically varying network delays and packet dropouts in Networked Control System (NCS) applications have been simultaneously addressed by time domain optimal tuning of fractional order (FO) PID controllers. Different variants of evolutionary algorithms are used for the tuning process and their performances are compared. Also the effectiveness of the fractional order PI(λ)D(μ)...

This paper proposes an output feedback method to stabilize and control networked control systems (NCSs). Random time delays and packet losses are treated separately when an NCS is modeled. The random time delays in the controller-to-actuator and sensor-to-controller links are modeled with two time-homogeneous Markov chains, while the packet losses are treated by the Dirac delta functions. An as...

A common approach to the implementation of digital systems is through the emulation of idealized continuous-time blocks in order to be able to leverage the rich expanse of results and design tools available in the continuous-time domain. So called sampled-data systems are now commonplace in practice and rely upon results that ensure that many properties of the nominal continuous-time system, in...

The deening characteristic of a networked control system (NCS) is having a feedback loop that passes through a local area computer network. This paper considers nonlinear systems controlled in this manner, and demonstrates that for suuciently high transmission rates, the network may be considered transparent. Three methods of scheduling data packets are compared: a static scheduler (token ring)...

In the research on the networked control systems (NCS) the performance of the control system is assumed to be affected by network induced parameters such as delays, jitters, packet losses, link failures. In this paper a reconfiguration of the network control is presented. The upper bound delay of the transmission time of a packet is monitored with the network calculus based algorithm. A modific...

This paper addresses exponential stability of linear networked control systems (NCS). More specifically, the paper considers a continuous-time linear plant in feedback with a linear sampled-data controller with an unknown time varying sampling rate, the possibility of data packet dropout, and an uncertain time varying delay. The main contribution of this paper is the derivation of new sufficien...