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An analytical method for well-formed workflow/Petri net verification of classical soundness

Julio Clempner (2014)

International Journal of Applied Mathematics and Computer Science

In this paper we consider workflow nets as dynamical systems governed by ordinary difference equations described by a particular class of Petri nets. Workflow nets are a formal model of business processes. Well-formed business processes correspond to sound workflow nets. Even if it seems necessary to require the soundness of workflow nets, there exist business processes with conditional behavior that will not necessarily satisfy the soundness property. In this sense, we propose an analytical method...

An LMI-based convex fault tolerant control of nonlinear descriptor systems via unknown input observers

Alberto Ortiz, Daniel Quintana, Victor Estrada-Manzo, Miguel Bernal (2024)

Kybernetika

This paper proposes a fault tolerant control scheme for nonlinear systems in descriptor form. The approach is based on the design of an unknown input observer in order to estimate the missing state variables as well as actuator faults, such design is carried out once a proper estimation error system is obtained via a recent factorization method; then, the estimated signals are employed in the control law in order to drive the states asymptotically to the origin despite actuator faults. The designing...

Approximation of control laws with distributed delays: a necessary condition for stability

Sabine Mondié, Michel Dambrine, Omar Santos (2002)

Kybernetika

The implementation of control laws with distributed delays that assign the spectrum of unstable linear multivariable systems with delay in the input requires an approximation of the integral. A necessary condition for stability of the closed-loop system is shown to be the stability of the controller itself. An illustrative multivariable example is given.

Asymptotic null controllability of bilinear systems

Fritz Colonius, Wolfgang Kliemann (1995)

Banach Center Publications

The region of asymptotic null controllability of bilinear systems with control constraints is characterized using Lyapunov exponents. It is given by the cone over the region of attraction of the maximal control set in projective space containing zero in its spectral interval.

Asynchronous sampling-based leader- following consensus in second-order multi-agent systems

Zhengxin Wang, Yuanzhen Feng, Cong Zheng, Yanling Lu, Lijun Pan (2018)

Kybernetika

This paper studies the leader-following consensus problem of second-order multi-agent systems with directed topologies. By employing the asynchronous sampled-data protocols, sufficient conditions for leader-following consensus with both constant velocity leader and variable velocity leader are derived. Leader-following quasi-consensus can be achieved in multi-agent systems when all the agents sample the information asynchronously. Numerical simulations are provided to verify the theoretical results....

Bounds of the matrix eigenvalues and its exponential by Lyapunov equation

Guang-Da Hu, Taketomo Mitsui (2012)

Kybernetika

We are concerned with bounds of the matrix eigenvalues and its exponential. Combining the Lyapunov equation with the weighted logarithmic matrix norm technique, four sequences are presented to locate eigenvalues of a matrix. Based on the relations between the real parts of the eigenvalues and the weighted logarithmic matrix norms, we derive both lower and upper bounds of the matrix exponential, which complement and improve the existing results in the literature. Some numerical examples are also...

Consensus of heterogeneous multi-agent systems with uncertain DoS attack: Application to mobile stage vehicles

Wen-Hai Yu, Hong-Jie Ni, Hui Dong, Dan Zhang (2020)

Kybernetika

In this paper, the consensus of heterogeneous multi-agent systems (MASs) with uncertain Deny-of-Service (DoS) attack strategies is studied. In our system, all agents are time synchronized and they communicate with each other with a constant sampling period normally. When the system is under attack, all agents use the hold-input mechanism to update the control protocol. By assuming that the attack duration is upper bounded and the occurrence of the attack follows a Markovian jumping process, the...

Continuous feedback stabilization for a class of affine stochastic nonlinear systems

Mohamed Oumoun, Lahcen Maniar, Abdelghafour Atlas (2020)

Kybernetika

We investigate the state feedback stabilization, in the sense of weak solution, of nonlinear stochastic systems when the drift is quadratic in the control and the diffusion term is affine in the control. Based on the generalised stochastic Lyapunov theorem, we derive the necessary conditions and the sufficient conditions, respectively, for the global asymptotic stabilization in probability by a continuous feedback explicitly computed. The interest of this work is that the existing control methods...

Controllable systems of partial differential equations

František Tumajer (1986)

Aplikace matematiky

In the paper definitions of various kinds of stability and boundedness of solutions of linear controllable systems of partial differential equations are introduced and their interconnections are derived. By means of Ljapunov's functions theorems are proved which give necessary and sufficient conditions for particular kinds of stability and boundedness of the solutions.

Decentralized control for large-scale systems with time-varying delay and unmatched uncertainties

Wen-Jeng Liu (2011)

Kybernetika

Many real-world systems contain uncertainties and with time-varying delays, also, they have become larger and more complicated. Hence, a new decentralized variable structure control law is proposed for a class of uncertain large-scale system with time varying delay in the interconnection and time varying unmatched uncertainties in the state matrix. The proposed decentralized control law for the large-scale time-varying delay system is realized independently through the delayed terms and it can drive...

Decentralized output regulation of large scale nonlinear systems with delay

Zhengtao Ding (2009)

Kybernetika

This paper deals with output regulation of a class of large-scale nonlinear systems with delays. Each of the subsystems is in the output feedback form, with nonlinear functions of the subsystem output and the outputs of other subsystems. The system outputs are subject to unknown constant delays. Both the system dynamics and the measurements are subject to unknown disturbances generated from unknown linear exosystems. Decentralized control design approach is adopted to design local controllers using...

Delay differential systems with time-varying delay: new directions for stability theory

James Louisell (2001)

Kybernetika

In this paper we give an example of Markus–Yamabe instability in a constant coefficient delay differential equation with time-varying delay. For all values of the range of the delay function, the characteristic function of the associated autonomous delay equation is exponentially stable. Still, the fundamental solution of the time-varying system is unbounded. We also present a modified example having absolutely continuous delay function, easily calculating the average variation of the delay function,...

Design of a neuro-sliding mode controller for interconnected quadrotor UAVs carrying a suspended payload

Özhan Bingöl, Haci Mehmet Güzey (2023)

Kybernetika

In this study, a generalized system model is derived for interconnected quadrotor UAVs carrying a suspended payload. Moreover, a novel neural network-based sliding mode controller (NSMC) for the system is suggested. While the proposed controller uses the advantages of the robust structure of sliding mode controller (SMC) for the nonlinear system, the neural network component eliminates the chattering effects in the control signals of the SMC and increases the efficiency of the SMC against time-varying...

Design of reaching phase for variable structure controller based on Householder transformation

Goshaidas Ray, Sitansu Dey, T. K. Bhattacharyya (2005)

Kybernetika

The paper presents control signals generation methods, preventing the excitation of residual vibration in slightly damped oscillational systems. It is focused on the feedforward methods, as most of the vibrations in examined processes are induced by the control, while the influence of disturbances is mostly negligible. Application of these methods involves ensuring of the insensitivity to natural frequency change, which can be reached in classical approach only by considerable increase of transient...

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