Jain, Anoop

This paper presents a systematic control design methodology for the synchronization of a class of chaotic systems configured as the drive and response systems. We achieve state synchronization with a predefined bound on the state errors by exploiting the idea of barrier Lyapunov function and considering parametric uncertainties in the response system. Under a mild assumption on the initial state errors, we prove the asymptotic convergence of state errors to the origin. We also obtain explicit bounds on the state errors and estimated uncertain parameters in the post-design analysis. Simulations are carried out for Lü chaotic system to illustrate the adequacy of the proposed controller and the uncertain parametric estimator.

This paper proposes a cyber-resilient distributed control strategy equipped with attack detection capabilities for islanded AC microgrids in the presence of bounded stealthy Byzantine cyber attacks affecting both frequency and power information exchanged among neighboring distributed generators (DGs). The proposed control methodology relies on the construction of an auxiliary layer and the establishment of effective inter-layer cooperation between the actual DGs in the control layer and the virtual DGs in the auxiliary layer. This cooperation aims to achieve robust frequency restoration and proportional active power-sharing. It is shown that the in situ presence of a concealed auxiliary layer not only guarantees resilience against stealthy bounded attacks on both frequency and power measurements but also facilitates a network-enabled attack identification mechanism. The paper provides rigorous proof of the stability of the closed-loop system and derives bounds for frequency and power deviations under attack conditions, offering insights into the impact of the attack signal, control and pinning gains, and network connectivity on the system's convergence properties. The performance of the proposed controllers is illustrated by simulating a networked islanded AC microgrid in a Simulink environment showcasing both attributes of attack resilience and attack detection.

Collision avoidance and connectivity preservation are two contrasting issues in multi-agent formation control problems. This paper proposes a distributed control design methodology to stabilize a desired formation shape in a multi-agent system while incorporating these two factors simultaneously. Contrary to a simplifying point mass assumption, we consider that agents in the group are characterized by a circular disk-type structure of different radii. Collision avoidance and connectivity preservation in the group are handled by applying time-varying constraints on the inter-center distances among neighboring agents. The concept of asymmetric time-varying barrier Lyapunov function is exploited to derive the stabilizing distributed control law, under a mild assumption on the initial conditions and a feasibility condition relating dimensions of the desired formation with the lower and upper limits of the barrier functions. We also obtain analytical bounds on the various post-design signals and illustrate the results through a simulation example. Finally, the effect of input saturation is discussed, and a comparison with the sensing-region-dependent potential function-based control design approach from the existing literature is provided.

A partially distributed economic dispatch algorithm, which renders optimal value in fixed time with the objective of supplying the load requirement as well as the power transmission losses, is proposed in this article. The transmission losses are modeled using Kron's B\text{-}$loss formula, under a few (standard) assumptions on the values of B\text{-}$coefficients. The total power supplied by the generators is subject to time-varying equality constraints due to the time-varying nature of the transmission losses. Using Lyapunov stability and optimization theory, we prove the convergence of the proposed algorithm to the optimal value within a fixed time, which depends on the {-}loss coefficients, cost function parameters associated with each generator, and the interaction topology among them. Finally, two test cases, including an IEEE-57 bus system, are simulated to illustrate the performance of the proposed algorithm.

This brief addresses the problem of safe circumnavigation around a hostile target by a nonholonomic robot, with the objective of maintaining a desired safe distance from the target. Our solution approach involves incorporating an auxiliary circle into the problem formulation, which assists in navigating the robot around the target using available range-based measurements. By leveraging the concept of a barrier Lyapunov function (BLF), we propose a novel control law that ensures stable circumnavigation around the target while preventing the robot from entering the safety circle. This controller is designed based on a parameter that depends on the radii of three circles, namely the stabilizing circle, the auxiliary circle, and the safety circle. By identifying an appropriate range for this design parameter, we rigorously prove the stability of the desired equilibrium of the closed-loop system. Additionally, we provide an analysis of the robot’s motion within the auxiliary circle, which is influenced by a gain parameter in the proposed controller. Simulation and experimental results validate the theoretical findings. © 1993-2012 IEEE.

This paper addresses the problem of output consensus in linear passive multi-agent systems under the False Data Injection (FDI) attacks. Our formulation relies on an event-based cryptographic authentication scheme for sensor integrity and considers FDI attacks at the actuator end, inspired by their practical nature and usages. For secure consensus, we propose (i) a passivity-based approach for detecting FDI attacks on the system and (ii) a Zeno-free event-triggered observer-based switching controller, which switches between the normal and the defense modes following an attack detection. We show that the closed-loop system achieves practical consensus under the controller's action in the defense mode. Two case studies are provided to support the theoretical findings. © 2025 Elsevier B.V.