scholarly journals Consensus Formation Control and Obstacle Avoidance of Multiagent Systems with Directed Topology

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lichao Wang ◽  
Xing Li ◽  
Bingyou Liu ◽  
Zhengzheng Zhang
Keyword(s):  
Obstacle Avoidance ◽  
Multiagent Systems ◽  
Formation Control ◽  
Tracking Problem ◽  
Consensus Formation ◽  
Control Laws ◽  
Directed Topology ◽  
Control Protocol ◽  
Formation Tracking ◽  
Avoidance Control

This study addresses the problems of formation control and obstacle avoidance for a class of second-order multiagent systems with directed topology. Formation and velocity control laws are designed to solve the formation tracking problem. A new obstacle avoidance control law is also proposed to avoid obstacles. Then, the consensus control protocol consists of the formation, velocity, and obstacle avoidance control laws. The convergence of the proposed control protocol is analyzed by a redesigned Lyapunov function. Finally, the effectiveness of theoretical results is illustrated by simulation examples. The simulation results show that the formation tracking problem of the given multiagent systems can be realized and obstacles can be avoided under the proposed control protocol.

scholarly journals A Distributed Formation Control Scheme with Obstacle Avoidance for Multiagent Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xiaowu Yang ◽  
Xiaoping Fan
Keyword(s):  
Obstacle Avoidance ◽  
Multiagent Systems ◽  
Formation Control ◽  
Adaptive Controller ◽  
Control Input ◽  
Control Laws ◽  
Integral Term ◽  
Control Scheme ◽  
The Stability ◽  
Avoidance Problem

This study considers the problem of formation control for second-order multiagent systems. We propose a distributed nonlinear formation controller where the control input of each follower can be expressed as a product of a nonlinear term that relies on the distance errors under the leader–follower structure. In the leader–follower structure, a small number of agents are assumed to be the leaders, and they are responsible for steering a group of agents to the specific destination, while the rest of the agents are called followers. The stability of the proposed control laws is demonstrated by utilizing the Lyapunov function candidate. To solve the obstacle avoidance problem, the artificial potential approach is employed, and the agents can avoid each possible obstacle successfully without getting stuck in any local minimum point. The control problem of multiagent systems in the presence of unknown constant disturbances is also considered. To attenuate such disturbances, the integral term is introduced, and the static error is eliminated through the proposed PI controller, which makes the system stable; the adaptive controller is designed to reduce the effect of time-varying disturbances. Finally, numerical simulation results are presented to support the obtained theoretical results.

Fast Convergence of Multi-quadrotor Cooperation Using Weighted-Neighbor-based Control

Robotica ◽  
2021 ◽  
pp. 1-18
Author(s):  
Zhicheng Hou ◽  
Gong Zhang
Keyword(s):  
Real Time ◽  
Formation Control ◽  
Control Method ◽  
A Priori ◽  
Fast Convergence ◽  
Tracking Problem ◽  
Not Given ◽  
Control Protocol ◽  
Formation Tracking ◽  
Robot Systems

SUMMARY In this paper, a weighted-neighbor-based cooperation control of multi-quadrotor systems is investigated. A formation tracking problem is treated, where the reference formation trajectory (RFT) is not given a priori. The RFT is only available to some of the quadrotors (i.e. the leaders). In order to attain the fast convergence of the agents, we propose an algorithm to calculate the neighbors’ weights in decentralized way. Then, the weights are used to compose the formation controller. Compared to the widely used average-neighbor-based control method, the proposed control protocol can increase the convergence speed of the cooperation error. Since the formation control is improved in topological scale, the utilization of the proposed algorithms can be extended on any multi-robot systems. We show the improvement of the proposed control protocol by theoretical proof, simulation, and real-time experiments.

scholarly journals Formation Tracking Control and Obstacle Avoidance of Unicycle-Type Robots Guaranteeing Continuous Velocities

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4374
Author(s):  
Jose Bernardo Martinez ◽  
Hector M. Becerra ◽  
David Gomez-Gutierrez
Keyword(s):  
Obstacle Avoidance ◽  
Tracking Control ◽  
Global Coordinate System ◽  
Avoidance Task ◽  
Time Varying ◽  
Control Laws ◽  
Formation Tracking ◽  
Control Scheme ◽  
First Time ◽  
Hierarchical Scheme

In this paper, we addressed the problem of controlling the position of a group of unicycle-type robots to follow in formation a time-varying reference avoiding obstacles when needed. We propose a kinematic control scheme that, unlike existing methods, is able to simultaneously solve the both tasks involved in the problem, effectively combining control laws devoted to achieve formation tracking and obstacle avoidance. The main contributions of the paper are twofold: first, the advantages of the proposed approach are not all integrated in existing schemes, ours is fully distributed since the formulation is based on consensus including the leader as part of the formation, scalable for a large number of robots, generic to define a desired formation, and it does not require a global coordinate system or a map of the environment. Second, to the authors’ knowledge, it is the first time that a distributed formation tracking control is combined with obstacle avoidance to solve both tasks simultaneously using a hierarchical scheme, thus guaranteeing continuous robots velocities in spite of activation/deactivation of the obstacle avoidance task, and stability is proven even in the transition of tasks. The effectiveness of the approach is shown through simulations and experiments with real robots.

scholarly journals Fuzzy Formation Control and Collision Avoidance for Multiagent Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Yeong-Hwa Chang ◽  
Chun-Lin Chen ◽  
Wei-Shou Chan ◽  
Hung-Wei Lin ◽  
Chia-Wen Chang
Keyword(s):  
Collision Avoidance ◽  
Multiagent Systems ◽  
Formation Control ◽  
Descent Method ◽  
Minimum Problem ◽  
Gradient Descent Method ◽  
Consensus Formation ◽  
Distributed Information ◽  
Graph Theoretic ◽  
Learning Rules

This paper aims to investigate the formation control of leader-follower multiagent systems, where the problem of collision avoidance is considered. Based on the graph-theoretic concepts and locally distributed information, a neural fuzzy formation controller is designed with the capability of online learning. The learning rules of controller parameters can be derived from the gradient descent method. To avoid collisions between neighboring agents, a fuzzy separation controller is proposed such that the local minimum problem can be solved. In order to highlight the advantages of this fuzzy logic based collision-free formation control, both of the static and dynamic leaders are discussed for performance comparisons. Simulation results indicate that the proposed fuzzy formation and separation control can provide better formation responses compared to conventional consensus formation and potential-based collision-avoidance algorithms.

Potential function-based path-following control of an autonomous underwater vehicle in an obstacle-rich environment

2016 ◽  
Vol 39 (8) ◽  
pp. 1236-1252 ◽  
Author(s):  
Basant Kumar Sahu ◽  
Bidyadhar Subudhi
Keyword(s):  
Potential Function ◽  
Obstacle Avoidance ◽  
Autonomous Underwater Vehicle ◽  
Path Following ◽  
Underwater Vehicle ◽  
Repulsive Force ◽  
Control Laws ◽  
Path Following Control ◽  
Avoidance Control ◽  
Solid Obstacles

This paper presents the development of simple but powerful path-following and obstacle-avoidance control laws for an underactuated autonomous underwater vehicle (AUV). Potential function-based proportional derivative (PFPD) as well as a potential function-based augmented proportional derivative (PFAPD) control laws are developed to govern the motion of the AUV in an obstacle-rich environment. For obstacle avoidance, a mathematical potential function is used, which formulates the repulsive force between the AUV and the solid obstacles intersecting the desired path. Numerical simulations are carried out to study the efficacy of the proposed controllers and the results are observed. To reduce the values of the overshoots and steady-state errors identified due to the application of PFPD controller a PFAPD controller is designed that drives the AUV along the desired trajectory. From the simulation results, it is observed that the proposed controllers are able to drive the AUV to track the desired path, avoiding the obstacles in an obstacle-rich environment. The results are compared and it is observed that the PFAPD outperforms the PFPD to drive the AUV along the desired trajectory. It is also proved that it is not necessary to employ highly complicated controllers for solving obstacle-avoidance and path-following problems of underactuated AUVs. These problems can be solved with the application of PFAPD controllers.

Time-varying formation finite-time tracking control for multi-UAV systems under jointly connected topologies

2017 ◽  
Vol 10 (4) ◽  
pp. 478-490 ◽  
Author(s):  
Tianyi Xiong ◽  
Zhiqiang Pu ◽  
Jianqiang Yi
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Formation Control ◽  
Time Varying ◽  
Content Type ◽  
Finite Time Stability ◽  
Control Protocol ◽  
Finite Time Convergence ◽  
Switching Topologies ◽  
Formation Tracking

Purpose The purpose of this paper is to investigate the time-varying finite-time formation tracking control problem for multiple unmanned aerial vehicle systems under switching topologies, where the states of the unmanned aerial vehicles need to form desired time-varying formations while tracking the trajectory of the virtual leader in finite time under jointly connected topologies. Design/methodology/approach A consensus-based formation control protocol is constructed to achieve the desired formation. In this paper, the time-varying formation is specified by a piecewise continuously differentiable vector, while the finite-time convergence is guaranteed by utilizing a non-linear function. Based on the graph theory, the finite-time stability of the close-loop system with the proposed control protocol under jointly connected topologies is proven by applying LaSalle’s invariance principle and the theory of homogeneity with dilation. Findings The effectiveness of the proposed protocol is verified by numerical simulations. Consequently, the proposed protocol can successfully achieve the predefined time-varying formation in finite time under jointly connected topologies while tracking the trajectory generated by the leader. Originality/value This paper proposes a solution to simultaneously solve the control problems of time-varying formation tracking, finite-time convergence, and switching topologies.

Formation and obstacle avoidance control for multiagent systems

2011 ◽  
Vol 9 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Jing Yan ◽  
Xinping Guan ◽  
Xiaoyuan Luo ◽  
Fuxiao Tan
Keyword(s):  
Obstacle Avoidance ◽  
Multiagent Systems ◽  
Avoidance Control
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