This paper investigates a robust cooperative path following control algorithm for an unmanned surface vessel and unmanned aerial vehicles (USV-UAVs) that releases the design complexity and command transmission requirements for the potential significance to implement a maritime square search mission. The latter is a classical search pattern suggested by the international aeronautical and maritime search and rescue (IAMSAR) manual. To program the reference signals for the USV-UAVs simultaneously, the reference routes are programmed that uses a virtual ship and a virtual aerial. Therein, the information of the virtual aerials can be mapped from a virtual ship. Further, the desired attitude angles are derived under the cooperative virtual guidance framework. For a control part, a novel threshold rule of the dynamic event-triggered mechanism is reconstructed according to output errors to avoid the artificial parameter tuning and reduce the data transmission load from the controllers to the actuators. Besides, a L-function is designed to eliminate an effect caused by the model nonlinearities and disturbances. This ensures a lower design complexity of the control system. The stability of the proposed control algorithm is proved via the Lyapunov theorem. Finally, the effectiveness and the reasonable are evaluated on the simulation platform.

In this article, an anti-attack event-triggered secure control scheme for a class of nonlinear multi-agent systems with input quantization is developed. With the help of neural networks approximating unknown nonlinear functions, unknown states are obtained by designing an adaptive neural state observer. Then, a relative threshold event-triggered control strategy is introduced to save communication resources including network bandwidth and computational capabilities. Furthermore, a quantizer is employed to provide sufficient accuracy under the requirement of a low transmission rate, which is represented by the so-called a hysteresis quantizer. Meanwhile, to resist attacks in the multi-agent network, a predictor is designed to record whether an edge is attacked or not. Through the Lyapunov analysis, the proposed secure control protocol can ensure that all the closed-loop signals remain bounded under attacks. Finally, the effectiveness of the designed scheme is verified by simulation results.

This article investigates an output consensus control problem for heterogeneous multi-agent systems with switching disconnected networks. As compared to similar works, each follower can measure only part information of the leader’s output in this paper, which lightens the measurement burden of simple agents when the dimension of leader’s output is large-scaled. In this case, due to the coexistence of incomplete measurements of leader’s output and disconnected networks, the outputs of some agents can deviate from the leader though there exists the observer-based control on them. In order to overcome this difficulty, we utilize the theory of switching unstable systems and propose a novel segmented time unit method. With the aid of this method, the switching intervals are segmented into some time units. Then by analyzing the cooperative control rule within the time units, the stabilizing characteristics of switching behaviors can be obtained to offset the divergence during the switching intervals. On this basis, a novel segmented time-varying Lyapunov function is developed to analyze the error states and sufficient criteria for the output consensus are derived. At last, a numerical simulation is shown to verify the theoretical results. Note to Practitioners —Most existing works on switching disconnected networks require that the leader (or the exosystem) is critically stable (or stable). However, unstable high-dimensional leader widely exists in the fields of multi-agent systems, such as the formation control of MASs where the agents are affine functions of time. On this account, this paper studies multi-agent systems with unstable high-dimensional leader under switching disconnected networks. To solve this problem, a novel segmented time unit method is proposed in this paper to study multi-agent systems with switching disconnected networks and incomplete leader measurement. Based on the segmented time unit approach, the observer-based control protocols and switching signals are given to realize the overall consensus. Numerical simulations suggest that this approach is feasible but it has not been tested in production. Future works will consider the formation control problem with switching disconnected networks and incomplete leader measurement.

This paper investigates the finite-time-prescribed performance-based (FTPP) platoon formation control problem of unmanned surface vehicles (USVs) with connectivity preservation andcollisionavoidance.Eachvehicleissubjecttounmeasuredvelocities, model uncertainties, external disturbances and actuator input delay. By introducing a finite-time performance function (FTPF), the desired transient and steady-state performances can be guaranteed in finite time, which makes the line-of-sight (LOS) error and angle error be limited within the desired constraints to achieve collision avoidance and connectivity maintenance. Furthermore, a relevant variable containing constrained upper and lower bounds is designed to further realize the FTPP with asymmetric properties. In order to recover unmeasured velocity information, estimate uncertain dynamics of the vehicle and compensate for external disturbances, an extended state observer (ESO) based on position-heading information is proposed. Thereinto, the event-triggered mechanism is introduced to reduce the communication burden from the sensor to the observer channel. The effects of actuator input delay are eliminated by using the Pade approximation transform. A second-order linear tracking differentiator (TD) is introduced into the kinematic design to avoid the measurement of acceleration in the dynamics control design. The stability analysis shows that the proposed control scheme ensures that all signals of the USVs are bounded, and the Zeno behavior will not occur. Moreover, the distance between the two neighboring USVs converges to the prescribed range, meanwhile, the tracking angle error limits to a desired arbitrarily small region within finite time. Finally, the simulation results further confirm the effectiveness of the proposed control scheme

To cope with the problem of repeatedly triggering collision avoidance conditions that collision avoidance algorithms used in containment control systems, this article investigates the reconfiguration of communication network topology for the multi-unmanned surface vehicle (USV) containment control system, which is from the perspective of algebraic connectivity of the system topology. By analyzing the relationship between the algebraic connectivity of the network topology composed of followers and the converging positions of followers and considering the capability of the system to resist external disturbances and avoid collisions within the system, a multi-USV containment control system topology reconfiguration strategy based on the algebraic connectivity is proposed. The strategy regards the desired algebraic connectivity as the control objective. By identifying the USVs involved in the cooperative task and their communication links in a decentralized way, each USV in the system is able to independently add and delete communication links, thus obtaining a system topology that matches the control objective. Under the reconfigured system topology, the final convergence position of the followers is relatively dispersed. Systems with such characteristics have better collision avoidance and antidisturbance properties, which can compensate to a certain extent for the limitations of traditional correlation algorithms under the influence of complex marine environments. Finally, the simulation and experimental results validate the effectiveness of the topology reconfiguration strategy proposed in this article for multi-USV containment control systems.