Path-Following Control With Obstacle Avoidance of Autonomous Surface Vehicles Subject to Actuator Faults

This paper investigates the path-following control problem with obstacle avoidance of autonomous surface vehicles in the presence of actuator faults,uncertainty and external disturbances.Autonomous surface vehicles inevitably suffer from actuator faults in complex sea environments,which may cause existing obstacle avoidance strategies to fail.To reduce the influence of actuator faults,an improved artificial potential function is constructed by introducing the lower bound of actuator efficiency factors.The nonlinear state observer,which only depends on measurable position information of the autonomous surface vehicle,is used to address uncertainties and external disturbances.By using a backstepping technique and adaptive mechanism,a path-following control strategy with obstacle avoidance and fault tolerance is designed which can ensure that the tracking errors converge to a small neighborhood of zero.Compared with existing results,the proposed control strategy has the capability of obstacle avoidance and fault tolerance simultaneously.Finally,the comparison results through simulations are given to verify the effectiveness of the proposed method.

Long Duration Coverage Control of Multiple Robotic Surface Vehicles Under Battery Energy Constraints

Dear Editor,This letter addresses long duration coverage problem of multiple robotic surface vehicles(RSVs) subject to battery energy constraints,in addition to uncertainties and disturbances. An anti-disturbance energy-aware control method is proposed for performing coverage task of RSVs. Firstly, a centroidal Voronoi tessellation(CVT) is used to optimize the partition of the given coverage area.

Multi-ASV Collision Avoidance for Point-to-Point Transitions Based on Heading-Constrained Control Barrier Functions With Experiment

Dear Editor, Collision avoidance is critical for safe operations of multiple autonomous surface vehicles(ASVs). It is a challenging task to design collision-free control laws to ensure safety, especially in a crowded sea environment. This letter presents a collision-free pointto-point transition strategy for multiple ASVs subject to static obstacles, dynamic obstacles and neighboring ASVs based on control barrier functions(CBFs).

Data-Driven Learning Extended State Observers for Nonlinear Systems:Design,Analysis and Hardware-in-Loop Simulations

Dear Editor, This paper considers the disturbance/uncertainty estimation of first-order nonlinear system subject to fully unknown internal dynamic, external disturbance, and unknown control input gain.Compared with existing extended state observer(ESO) where priori knowledge of model parameter such as nominal input gain should be known as a priori.

洋流干扰下无人船限制水域直线跟踪安全视距制导

The collision-free straight-line following of an unmanned surface vehicle(USV)moving in a constrained water region subject to stationary and moving obstacles is addressed in this paper.USV systems are normally subjected to surge velocity constraints,yaw rate constraints,and unknown ocean currents.Herein,a safety-certificated line-of-sight(LOS)guidance method is proposed to achieve a constrained straight-line following task.First,an antidisturbance LOS guidance law is designed based on the LOS guidance scheme and an extended state observer.Furthermore,collision avoidance with waterway boundaries and stationary/moving obstacles is encoded in control barrier functions,utilizing which the safety constraints are transformed into input constraints.Finally,safety-certificated guidance signals are obtained by solving a quadratic programming problem subject to input constraints.Using the proposed safety-certified LOS guidance method,the USV can accomplish a straight-line following task with guaranteed input-to-state safety.Simulation results substantiate the efficacy of the proposed safety-certificated LOS guidance method for the straight-line following of USVs moving in a constrained water region subject to unknown ocean currents.

Safety-Critical Model-Free Control for Multi-Target Tracking of USVs with Collision Avoidance

Dear editor,This letter addresses the multi-target tracking of underactuated unmanned surface vehicles(USVs)subject to multiple stationary/moving obstacles.The kinetic model parameters of each USV are totally unknown.A safety-critical model-free control method is proposed for tracking multiple targets with a collision-free containment formation.Specifically,a distributed containment extended state observer(DCESO)is designed to estimate the convex hull spanned by the multiple targets.At the kinematic level,a collision-free kinematic guidance law is presented using a control barrier function(CBF)and an extended state observer for each follower USV.At the kinetic level,a model-free position tracking control law by using an adaptive ESO(AESO)is presented for each follower USV.By the designed safety-critical model-free control method,cooperative tracking of multiple targets under multiple stationary/moving obstacles can be achieved using completely unknown kinetic model parameters.Simulations are provided to illustrate the efficacy of the proposed safety-critical model-free control method for a fleet of USVs.

人工智能2.0时代的群体智能理论与技术专题序言

1引言进入21世纪,传感技术、通信技术与人工智能技术的快速发展对工程系统集成与管控方式产生了深刻的影响。从大规模国家基础设施系统到各类军事集成无人系统日益呈现出网络化的结构特征和智能化的单元特性。在迈入人工智能2.0时代,信息化、智能化与网络化融合发展的趋势日益凸显并浮现出引领第四次工业革命的趋势。在此背景下。

Event-triggered control for containment maneuvering of second-order MIMO multi-agent systems with unmatched uncertainties and disturbances

This paper is concerned with distributed containment maneuvering of second-order Multi-Input Multi-Output(MIMO)multi-agent systems with non-periodic communication and actuation.The agent is subject to unmatched nonlinear dynamics and external disturbances.Event-triggered containment maneuvering control methods is developed based on a modular design.Specifically,an estimator module is constructed based on neural networks and the nonperiodic obtained follower information through event-triggered communication.Next,a controller module is designed by using the identified information from the estimator module and a third-order linear tracking differentiator.An event-triggered mechanism is introduced for updating the actuator.Then,a path update law is designed based on the non-periodic leader information through event-triggered communication.The closed-loop system cascaded by the estimation subsystem and control subsystem is proved to be input-to-state stable,and Zeno behavior is excluded in the control process.The proposed method is capable of reducing the consumption of communication and actuation.A simulation example is provided to substantiate the effectiveness of the proposed event-triggered control method for distributed containment maneuvering of second-order MIMO multi-agent systems.

Adaptive distributed observer design for containment control of heterogeneous discrete-time swarm systems

This paper develops both adaptive distributed dynamic state feedback control law and adaptive distributed measurement output feedback control law for heterogeneous discrete-time swarm systems with multiple leaders.The convex hull formed by the leaders and the system matrix of leaders is estimated via an adaptive distributed containment observer.Such estimations will feed the followers so that every follower can update the system matrix of the corresponding adaptive distributed containment observer and the system state of their neighbors.The followers cooperate with each other to achieve leader-follower consensus and thus solve the containment control problem over the network.Numerical results demonstrate the effectiveness and computational feasibility of the proposed control laws.