This paper focuses on a moving-target-enclosing control problem for nonholonomic multi-agent systems with bearing-only measurements and collision avoidance. Due to the lack of distance measurements, a bearing-only observer is designed first to estimate the complete relative position between each agent and the target. Simultaneously, an auxiliary signal generator is designed for an auxiliary multi-agent system to produce several reference circular trajectories for its agents, while guaranteeing collision avoidance. Based on the bearing-only observer and the auxiliary signal generator, a dynamic controller is proposed by feedback linearization approach. Sufficient conditions for asymptotic stability and the guaranteed collision avoidance are given. Two simulation examples validate the effectiveness of proposed scheme.
This paper studies event-triggered uniform ultimate boundedness control for singular linear systems with time-varying delays. A nonperiodic event-triggered mechanism with an exponentially decaying threshold and a positive absolute threshold is introduced to reduce redundant transmissions and exclude Zeno behavior. By treating the triggering-induced measurement error as a bounded perturbation, the closed-loop system is transformed into a singular delay system. A Halanay-type estimation technique is incorporated into the analysis to derive sufficient conditions guaranteeing admissibility and uniform ultimate boundedness of the closed-loop system. In contrast to conventional Lyapunov–Krasovskii functional approaches, the proposed method avoids augmented functionals with multiple integral terms and numerous auxiliary variables, resulting in computationally efficient LMI-based design conditions. These conditions provide a tractable co-design method for the controller and triggering parameters, while characterizing the effects of the delay bound, decay rate, thresholds, and ultimate bound. Finally, a numerical example, an electrical circuit application, and a comparative example with an existing LKF-based method are provided to verify the theoretical results and demonstrate the practical applicability and computational advantages of the proposed approach.
This article investigates the formation reconfiguration problem of autonomous aerial vehicle–autonomous ground vehicle (AAV–AGV) system and constructs the real-time desired configuration of the formation system in the moving stereo domain. Firstly, since AAVs and AGVs move in different dimensions, in order to solve the problem of cooperative control of heterogeneous formation, the cross-dimension formation protocol method is employed, which enables the agents in the same cluster to form the desired time-varying formation in their respective dimensions, while different clusters move in different dimensions. Secondly, each agent in the heterogeneous formation is positioned to achieve the target configuration. At the same time, the sum of the squares of the Euclidean distances between it and its corresponding agents are minimized to ensure the optimal energy consumption during the formation reconfiguration process. According to the theories and methods above, the problem is reformulated as a time-varying noncooperative game. Subsequently, a distributed time-varying Nash equilibrium search algorithm based on time transformation technique and gradient descent technique is developed. This algorithm enables the heterogeneous system to complete the formation reconfiguration within the predefined time. The convergence of the algorithm is proved by Lyapunov stability theorem and a iterative method. Finally, a simulation example is provided to prove the effectiveness of the algorithm.
Eduardo Sontag and coauthors studied Input-to-Output Stability (IOS) and the output asymptotic gain property. These notions changed control theory and recently had an impact on robust adaptive control through the Deadzone-Adapted Disturbance Suppression (DADS) control scheme. Moreover, recently the notion of IOS was extended to systems described by Partial Differential Equations (PDEs). In this work, we celebrate Eduardo Sontag by combining DADS and IOS for PDEs: we study the partial-state regulation problem for a scalar Ordinary Differential Equation (ODE) which is interconnected with a possibly infinite-dimensional system. In such a case the DADS control scheme can allow an escape from the requirements of the small-gain theorem that is mainly used for partial-state feedback. We show the design procedure of partial-state DADS controllers and we prove robust regulation even in the presence of external inputs (disturbances) without assuming knowledge of any disturbance/parameter bounds. The DADS controller is applied to three different cases of the interconnection of an ODE with an almost completely unknown: (a) heat PDE, (b) transport PDE, and (c) wave PDE with viscous damping. We show that the same DADS controller can achieve robust regulation in all three cases.
