Control Of Second-order Multi-agent Systems Research Articles

Finite-time consensus control of second-order multi-agent systems with input saturation constraint

A novel finite-time consensus technique is derived for second-order linear multi-agent systems with input saturation constraints. The hyperbolic tangent–based saturation function is presented for achieving input saturation while reducing the chattering issue of classical saturation functions. The leader-following consensus controller with a single saturation function is constructed to address the issue of saturation level partition between position feedback and velocity feedback. Theoretically, the property of finite-time consensus, bounded input, and smoothness of a closed-form system are proved by the Lyapunov theory in detail. Numerical simulations are conducted to exhibit the effectiveness of the proposed method fully.

Containment control for second-order multi-agent systems with time-varying delays via variable-augmented-based free-weighting matrices

This paper investigates the containment control problem for multi-agent systems (MASs), where the time-varying communication delays are considered. The aim of this paper is to introduce new methods for the containment control research of MASs with time-varying delays. To obtain better results on maximum admissible upper bounds (MAUBs) of the delays to ensure the containment control, the variable-augmented-based free-weighting matrices (VABFWMs) method is introduced to avoid the higher-order terms of time-varying delays in estimating the derivative of the Lyapunov-Krasovskii functionals (LKFs). So our method no longer requires the quadratic function negative-determination lemma. In addition, by utilizing the proposed method, we design a containment controller to ensure that all followers are included into the convex hull formed by leaders. Finally, a numerical example is presented to illustrate the feasibility and superiority of our method.

Finite-Time Prescribed Performance Time-Varying Formation Control for Second-Order Multi-Agent Systems with Non-Strict Feedback Based on a Neural Network Observer

Finite-Time Prescribed Performance Time-Varying Formation Control for Second-Order Multi-Agent Systems with Non-Strict Feedback Based on a Neural Network Observer

Parameter variational based adaptive bipartite formation control of second-order multi-agent systems with antagonistic interactions

This article mainly concentrates on researching the leader-following bipartite formation of second-order nonlinear multi-agent systems (MASs) with antagonistic interactions and time-varying delay. A novel distributed feedback control and impulsive control strategy is proposed for realizing the bipartite formation. By establishing an error system, the bipartite formation issue of the MASs is transformed into the stability issue of the error systems. Sufficient conditions for achieving the bipartite formation of second-order nonlinear MASs are obtained by jointly employing the extended parameters variation formula, the comparison principle and the definition of average impulsive interval. In addition, in order to obtain the optimal control gains and control effects, an adaptive control strategy is taken into account by designing the adaptive updating laws. Ultimately, the effectiveness of the theoretical results is demonstrated by two numerical simulations.

Finite-time guarantee-cost [formula omitted] consensus control of second-order multi-agent systems based on sampled-data event-triggered mechanisms

This study presents a solution to the challenges of tracking consensus and guarantee-cost H∞ control in a specific set of second-order multi-agent systems with external disturbances. A proposed event-triggered control method based on periodic sampling data is presented for second-order multi-agent systems that include external disturbances. In contrast to the real-time monitoring of system state information used in the previous event-triggered mechanism, this approach collects system state information through periodic sampling. This ensures that the interval between two consecutive triggering moments is at least one sampling cycle, thereby preventing the controller from triggering infinitely within a finite time frame. A finite-time controller based on the sampled-data event-triggered mechanism is designed, and sufficient conditions to ensure the finite-time stability of the closed-loop system at a specified attenuation level are established using theoretical methods such as matrix analysis. For the given sampled-data event-triggered control protocol with a finite-time controller, a quadratic guarantee-cost function is introduced, and by designing control inputs and determining the parameters such as the finite-time upper bound T∗ and the H∞ performance index γ , the exact value of the upper bound of the system’s guarantee-cost function under the action of the designed controller is derived. Finally, the feasibility of the proposed control scheme is verified through numerical simulation.

Time-Varying Optimal Formation Control for Second-Order Multiagent Systems Based on Neural Network Observer and Reinforcement Learning.

This article addresses a distributed time-varying optimal formation protocol for a class of second-order uncertain nonlinear dynamic multiagent systems (MASs) based on an adaptive neural network (NN) state observer through the backstepping method and simplified reinforcement learning (RL). Each follower agent is subjected to only local information and measurable partial states due to actual sensor limitations. In view of the distributed optimized formation strategic needs, the uncertain nonlinear dynamics and undetectable states may jointly affect the stability of the time-varying cooperative formation control. Furthermore, focusing on Hamilton-Jacobi-Bellman optimization, it is almost incapable of directly dealing with unknown equations. Above uncertainty and immeasurability processed by adaptive state observer and NN simplified RL are further designed to achieve desired second-order formation configuration at the least cost. The optimization protocol can not only solve the undetectable states and realize the prescribed time-varying formation performance on the premise that all the errors are SGUUB, but also prove the stability and update the critics and actors easily. Through the above-mentioned approaches offer an optimal control scheme to address time-varying formation control. Finally, the validity of the theoretical method is proven by the Lyapunov stability theory and digital simulation.

Event-triggering Formation Control for Second-order Multi-agent Systems With Sampled Position Data

Event-triggering Formation Control for Second-order Multi-agent Systems With Sampled Position Data

Prescribed-time leader-following consensus and containment control for second-order multiagent systems with only position measurements

The problems of prescribed-time leader-following consensus and prescribed-time containment control for double-integrator multiagent systems (MASs) with only position measurements are investigated in this paper. An observer-based prescribed-time control protocol is proposed, in which the two groups of observers for estimating the consensus errors of each follower both converge to zero within a specified time. Furthermore, the proposed controller only relies on its own observers and does not need to obtain the data from observers embedded in its neighbor nodes. The sufficient conditions for the MASs to achieve the defined prescribed-time consensus and to fulfill the goal of prescribed-time containment control are, respectively, given. The effectiveness of the proposed control protocol is further verified by computer simulations.

Prescribed performance formation control for second-order multi-agent systems with connectivity and collision constraints

This paper studies the distributed formation control problem of second-order multi-agent systems (MASs) with limited communication ranges and collision avoidance constraints. A novel connectivity preservation and collision-free distributed control algorithm is proposed by combining prescribed performance control (PPC) and exponential zeroing control barrier Lyapunov functions (EZCBFs). In particular, we impose the time-varying performance constraints on the relative position and velocity errors between the neighboring agents, and then a PPC-based formation control algorithm is developed such that the connectivity of the communication graph can be preserved at all times, and the prescribed transient and steady performance on the relative position and velocity error can be achieved. Subsequently, by introducing the EZCBFs method, an inequality constraint condition on the control input is derived to guarantee the collision-free formation motion. By regarding the PPC-based formation controller as a nominal input, an actual formation control input is given by solving the quadratic programming (QP) problem such that each agent achieves collision-free formation motion while guaranteeing the connectivity and prescribed performance as much as possible. Finally, numerical simulation is carried out to validate the effectiveness of the proposed algorithm.

Consensus tracking iterative learning control of second-order multi-agent systems

In this paper, the problem of consensus tracking control for a class of second-order leader-following nonparametric uncertain multi-agent systems, which perform a given repetitive task over a finite interval with arbitrary initial error. By means of learning control and initial shift rectifying, a first-order attractor control algorithm is presented.In the tracking process, the proposed algorithm simultaneously rectifies all the initial state shifts, and after enough iterations, the all following multi-agents’ states perfectly track the leader’s state in the preset time interval. Finally, simulation results demonstrate the effectiveness of the learning control algorithm.

Event-triggered affine formation maneuver control for second-order multi-agent systems with sampled data

This paper addresses the affine formation maneuver problem for second-order multi-agent systems with distributed event-triggered controllers. For multiple leaders moving with constant accelerations, a sampled-data-based event-triggered proportional–integral controller is proposed to reduce the frequencies of controller update, where triggering moments are determined by the relative states between agent and its neighbors. Moreover, based on the proposed event-triggered control scheme, a self-triggered mechanism is designed to avoid continuous measurements for relative states and continuous calculating of local events at each discrete moment. Some sufficient conditions for achieving affine formation maneuver control are obtained and the Zeno behavior is naturally eliminated due to periodic sampling setting. Finally, the theoretical results are illustrated through numerical simulations.

Sliding mode based prescribed-time consensus tracking control of second-order multi-agent systems

In this work, we investigate the prescribed-time consensus tracking problem for second-order multi-agent systems under directed topology. A new hybrid distributed observer for each follower is developed to estimate the states of the leader in prescribed time. Based on the observer, a novel prescribed-time sliding mode surface that is nonsingular and the corresponding tracking controller are designed such that the full state consensus tracking is achieved within a prescribed time. The salient feature of the proposed control scheme lies in that not only accurate tracking can be achieved within the prescribed time but also the numerical implementation problem arising from the infinite time-varying gain is avoided. The effectiveness of the proposed method is confirmed by the numerical simulation.

Distributed Observer-Based Predefined-Time Consensus Control for Second-Order Multi-agent Systems

Distributed Observer-Based Predefined-Time Consensus Control for Second-Order Multi-agent Systems

Velocity-free distributed coordinated optimal control for second-order multi-agent systems

This paper solves the coordinated optimal consensus problem for second-order multi-agent systems without velocity information from the distributed perspective. Particularly, all the agents are driven towards a consensus at an optimal solution inside the intersection of multiple feasible sets that minimizes a global target function aggregated by a group of convex local ones. Each local target function is exclusively assigned to a respective agent. Also, each feasible set constructed by inequality and set constraints privately belongs to a respective agent. Resorting to a novel auxiliary dynamics, a velocity-free distributed coordinated optimal control strategy is proposed without relying on global topology information. Using convex theory under the Lyapunov framework, it is demonstrated that the concerned coordinated optimal control objective is fulfilled by implementing the proposed distributed control strategy despite no velocity information. Examples are finally given to confirm the control effectiveness.

Formation Control of Second-order Multi-agent Systems with Switching Topologies: A Time-delayed Impulsive Control Approach

Formation Control of Second-order Multi-agent Systems with Switching Topologies: A Time-delayed Impulsive Control Approach

Distributed Fixed-Time Tracking and Containment Control for Second-Order Multi-Agent Systems: A Nonsingular Sliding-Mode Control Approach

This paper focuses on distributed fixed-time tracking consensus and containment control problems of second-order multi-agent systems (MASs) with directed topology. To make the offline design and convergence time estimation of the consensus protocol for second-order MASs possible, a novel nonsingular sliding-mode control method is established by introducing a time-varying scaling function in the design of the sliding surface. Subsequently, sufficient conditions ensuring fixed-time tracking consensus and containment control of the second-order MASs are obtained by using the proposed nonsingular sliding-mode control method. The results show that the estimated convergence time of considered MASs is independent of the initial values and other parameters of the system, where the convergence time on the sliding surface can be prescribed. Ultimately, two numerical examples are illustrated to verify the validity of the obtained results.

Fuzzy Adaptive Group Obstacle Avoidance Control for Second-Order Multi-Agent Systems Under Fixed and Switching Topologies

This paper investigates the multi-group formation obstacle avoidance control problem of second-order nonlinear leader-follower multi-agent systems (MASs) with unknown nonlinear function and uncertain input disturbance. To make multi-group MASs achieve global consensus, a distributed global fuzzy adaptive control method is presented. Then, navigation functions are employed to make agents bypass obstacles and reach the target positions. The adaptive method is applied to adjust parameters online which can substantially reduce computation burdens and make trajectories of agents smooth. Without loss of generality, both fixed and switching interaction topologies are all taken into account. After that, through Lyapunov stability theory and algebraic graph theory, the feasibility of the method proposed in this paper has been proved. Finally, simulation examples are given to validate the effectiveness of the method proposed in this paper.

Event-triggered control for second-order multi-agent systems under denial-of-service attacks and white noises

Under the influence of additive communication noises and system noises, we investigate the event-triggered control problem for second-order multi-agent systems composed of double integrators or LC oscillators under random denial-of-service (DoS) attacks. Different from the previous cases where the attackers completely interrupt communication networks, we consider that attackers interrupt the communication network with a specific probability and can attack part or all communication links randomly. Based on this, the conditions on the attack duration and attack success probability are given when the system can still achieve consensus under random DoS attacks. In addition, the consensus bounds are expressed. Finally, two types of LC oscillator systems are used to illustrate the effectiveness of results.

Event-triggered bipartite consensus control algorithm design for nonlinear second-order multi-agent systems

Bipartite consensus of nonlinear second-order multi-agent systems with directed communication topology is investigated in this article. A kind of novel event-triggered control protocol is proposed, which based on relative information sensing. Different from some conventional event-triggered control for second-order multi-agent systems, the event-triggered control in distributed way for second-order multi-agent systems is studied in this article, which imply that the controller of each follower only needs to collect the local information. To eliminate too large control gain, the control gain of control protocol is further designed based on adaptive way. Moreover, these control algorithms prove that Zeno behavior can be avoided. Finally, the performance of the proposed control protocols is presented by virtue of two simulation examples.

Formation Control for Second-Order Multi-Agent Systems with Collision Avoidance

This paper deals with the formation control problem without collisions for second-order multi-agent systems. We propose a control strategy which consists of a bounded attractive component to ensure convergence to a specific geometrical pattern and a complementary repulsive component to guarantee collision-free rearrangement. For convergence purposes, it is assumed that the communication graph contains at least a directed spanning tree. The avoidance complementary component is formed by applying repulsive vector fields with unstable focus structure. Using the well-known input-to-state stability property a control law for second-order agents is derived in a constructive manner starting from the first-order case. We consider that every agent is able to detect the presence of any other agent in the surrounding area and also can measure and share both position and velocity with his predefined set of neighbours. The resulting control law ensures the convergence to the desired geometrical pattern without collisions during the transient behaviour, as well as bounded velocities and accelerations. Numerical simulations are provided to show the performance and effectiveness of the proposed strategy.