Fault Tolerant Control of Nonholonomic Mobile Robot Formations

2010 ◽  
pp. 50-83
Author(s):  
T. Dierks ◽  
B. T. Thumati ◽  
S. Jagannathan
Keyword(s):  
Formation Control ◽  
Fault Tolerant ◽  
Additional Term ◽  
Torque Control ◽  
Lyapunov Methods ◽  
Control Law ◽  
Control Laws ◽  
Learning Capabilities ◽  
The Stability ◽  
The Individual

In this chapter, a fault tolerant kinematic/torque control law is developed using backstepping for leader-follower based formation control in order to accommodate the dynamics of the robots and the formation in contrast with kinematic-based formation controllers. First, nominal control laws are derived for the leader and follower robots under the assumption of normal operation (no faults), and the stability of the individual robots and the formation is verified using Lyapunov methods. Subsequently, in the presence of state faults such as actuator fault, flat-tire etc., which could be incipient or abrupt in nature, an online fault detection and accommodation (FDA) scheme is derived to mitigate the effects of a fault by modifying the nominal controller. In other words, an additional term is introduced to the existing control law to minimize the effects of the fault, and this additional term is a function of the unknown fault dynamics which are recovered using the online learning capabilities of a neural network. Further, mathematical stability results are derived using Lyapunov theory, and both the FDA scheme and the formation errors are guaranteed to render asymptotic stability in the presence of faults. Numerical results are provided to verify the theoretical conjectures.

scholarly journals Circular Formation Control of Multiagent Systems with Any Preset Phase Arrangement

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lina Jin ◽  
Shuanghe Yu ◽  
Dongxu Ren
Keyword(s):  
Control Problem ◽  
Multiagent Systems ◽  
Formation Control ◽  
Closed Loop ◽  
Phase Distribution ◽  
The Other ◽  
Control Law ◽  
Closed Loop System ◽  
The Stability ◽  
Phase Arrangement

This paper deals with the circular formation control problem of multiagent systems for achieving any preset phase distribution. The control problem is decomposed into two parts: the first is to drive all the agents to a circle which either needs a target or not and the other is to arrange them in positions distributed on the circle according to the preset relative phases. The first part is solved by designing a circular motion control law to push the agents to approach a rotating transformed trajectory, and the other is settled using a phase-distributed protocol to decide the agents’ positioning on the circle, where the ring topology is adopted such that each agent can only sense the relative positions of its neighboring two agents that are immediately in front of or behind it. The stability of the closed-loop system is analyzed, and the performance of the proposed controller is verified through simulations.

Active Fault Tolerant Control Based on Fault Estimation

2014 ◽  
Vol 635-637 ◽  
pp. 1199-1202 ◽  
Author(s):  
Zheng Gao Hu ◽  
Guo Rong Zhao ◽  
Da Wang Zhou
Keyword(s):  
Active Fault ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Sliding Mode Observer ◽  
Fault Estimation ◽  
Control Law ◽  
Active Fault Tolerant Control ◽  
The Stability ◽  
Twisting Algorithm

For the chattering problem in the traditional sliding mode observer-based fault estimation, a second order sliding mode observer based on the Super-twisting algorithm was proposed. In order to avoid the cumbersome process of proving the stability of the Super-twisting algorithm, a Lyapunov function was adopted. An active fault tolerant control law was designed based on the fault estimation. Finally, simulation show the effectiveness of the proposed approach.

scholarly journals Robust Control Based Stability Analysis and Trajectory Tracking of Triple Link Robot Manipulator

2021 ◽  
Vol 54 (4) ◽  
pp. 641-647
Author(s):  
Mukul Kumar Gupta ◽  
Roushan Kumar ◽  
Varnita Verma ◽  
Abhinav Sharma
Keyword(s):  
Stability Analysis ◽  
Robust Control ◽  
Tracking Control ◽  
Robot Manipulator ◽  
Torque Control ◽  
Control Technique ◽  
Control Law ◽  
Worst Case ◽  
Control Techniques ◽  
The Stability

In this paper the stability and tracking control for robot manipulator subjected to known parameters is proposed using robust control technique. The modelling of robot manipulator is obtained using Euler- Lagrange technique. Three link manipulators have been taken for the study of robust control techniques. Lyapunov based approach is used for stability analysis of triple link robot manipulator. The Ultimate upper bound parameter (UUBP) is estimated by the worst-case uncertainties subject to bounded conditions. The proposed robust control is also compared with computer torque control to show the superiority of the proposed control law.

Optimal formation control with limited communication for multi-unmanned aerial vehicle in an obstacle-laden environment

2016 ◽  
Vol 231 (6) ◽  
pp. 979-997 ◽  
Author(s):  
Xiao Lin Ai ◽  
Jian Qiao Yu ◽  
Yong Bo Chen ◽  
Fang Zheng Chen ◽  
Yuan Chuan Shen
Keyword(s):  
Optimal Control ◽  
Control Problem ◽  
Formation Control ◽  
Control Laws ◽  
Control Approach ◽  
Practical Applications ◽  
Limited Communication ◽  
Aerial Vehicle ◽  
The Stability ◽  
Virtual Leader

This paper investigates the formation control problem of multiple unmanned aerial vehicles (UAVs) with limited communication in a known and realistic obstacle-laden environment. In order to deal with the limited communication constraints, the leader–follower strategy and the virtual leader strategy are integrated into an optimal control framework to formulate this formation control problem. This combination formation framework can be achieved by integrating a redefined directed graph and a proposed information vector. In more practical applications, an obstacle/collision avoidance strategy is achieved by constructing a non-quadratic cost function innovatively using a virtual flow field approach. The proposed optimal control laws, which derive from the local information rather than the global information, are proved to guarantee the stability of the close-loop system by an inverse optimal control approach. The simulation results demonstrate the effectiveness of the formation flight of multiple UAVs with limited communication in an obstacle-laden environment.

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.

Distributed fault-tolerant formation control for multiple unmanned aerial vehicles under actuator fault and intermittent communication interrupt

2021 ◽  
pp. 095965182097908
Author(s):  
Bing Han ◽  
Ju Jiang ◽  
Chaojun Yu
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Formation Control ◽  
Fault Tolerant ◽  
Input Saturation ◽  
Actuator Faults ◽  
Aerial Vehicles ◽  
Multiple Unmanned Aerial Vehicles ◽  
The Stability ◽  
Intermittent Communication ◽  
Formation System

This article develops a distributed adaptive fault-tolerant formation control scheme for the multiple unmanned aerial vehicles to counteract actuator faults and intermittent communication interrupt, where the issues on control input saturation and mismatched uncertainties are also addressed. The discontinuous communication protocol technique is exploited to achieve the stability of the formation system, if the conditions of dwell time and the rate of communication are satisfied. On the basis of the local information of neighboring unmanned aerial vehicles, a novel distributed adaptive mechanism is designed to estimate the bounds of actuator faults and uncertainties, where the input saturation is explicitly taken into consideration. The stability of the whole formation system under the designed fault-tolerant formation control strategy is analyzed using the Lyapunov approach. Finally, simulation results are presented to illustrate the effectiveness of the proposed scheme.

scholarly journals Passivity-Based Distributed Acquisition and Station-Keeping Control of a Satellite Constellation in Areostationary Orbit

2020 ◽  
Author(s):  
Emmanuel Sin ◽  
He Yin ◽  
Murat Arcak
Keyword(s):  
Control Law ◽  
Communication Link ◽  
Station Keeping ◽  
Interconnected System ◽  
Satellite Constellation ◽  
Compositional Approach ◽  
Communication Links ◽  
The Stability ◽  
The Individual ◽  
Present Simulation

Abstract We present a distributed control law to assemble a cluster of satellites into an equally-spaced, planar constellation in a desired circular orbit about a planet. We assume each satellite only uses local information, transmitted through communication links with neighboring satellites. The same control law is used to maintain relative angular positions in the presence of disturbance forces. The stability of the constellation in the desired orbit is proved using a compositional approach. We first show the existence and uniqueness of an equilibrium of the interconnected system. We then certify each satellite and communication link is equilibrium-independent passive with respective storage functions. By leveraging the skew symmetric coupling structure of the constellation and the equilibrium-independent passivity property of each subsystem, we show that the equilibrium of the interconnected system is stable with a Lyapunov function composed of the individual subsystem storage functions. We further prove that the angular velocity of each satellite converges to the desired value necessary to maintain circular, areostationary orbit. Finally, we present simulation results to demonstrate the efficacy of the proposed control law in acquisition and station-keeping of an equally-spaced satellite constellation in areostationary orbit despite the presence of unmodeled disturbance forces.

A Robustness Issue of Control Laws Designed by the Input-Shaping Methodology

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
S. M. Shahruz
Keyword(s):  
Switching Time ◽  
Input Shaping ◽  
Control Law ◽  
Control Laws ◽  
Switching Mechanism ◽  
The Stability

In this note, a robustness issue of control laws designed by the input-shaping methodology is brought to the fore. A control law designed by this methodology consists of a sequence of step inputs that are applied at designated time instants by a switching mechanism. It is shown that the stability of systems controlled by such control laws may not be robust in the presence of errors in the switching time instants.

Multiple Quadrotors Formation Flying Control Design and Experimental Verification

2019 ◽  
Vol 07 (01) ◽  
pp. 47-54 ◽  
Author(s):  
Jianan Wang ◽  
Zhengyang Zhou ◽  
Chunyan Wang ◽  
Jiayuan Shan
Keyword(s):  
Motion Capture ◽  
Formation Control ◽  
Formation Flying ◽  
Control Design ◽  
Euler Method ◽  
Control Law ◽  
Dynamics Model ◽  
Experimental Platform ◽  
Communication Constraint ◽  
The Stability

The formation control problem in multi-quadrotor systems is studied in this paper. Each quadrotor has limited access to its neighbors’ information due to communication constraint. First, the dynamics model of the quadrotor is linearized using Newton–Euler method. The distributed formation control law is then designed and the stability analysis is provided. An experimental platform is built with three Parrot Bebop drones and an indoor motion capture system. Numerical and experimental results are provided to show the effectiveness of the proposed algorithms.

scholarly journals Fault-Tolerant Region-Based Control of an Underwater Vehicle with Kinematically Redundant Thrusters

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Zool H. Ismail ◽  
Ahmad ’A. Faudzi ◽  
Matthew W. Dunnigan
Keyword(s):  
Lyapunov Function ◽  
Numerical Simulations ◽  
Fault Tolerant ◽  
Underwater Vehicle ◽  
Control Law ◽  
Redundancy Resolution ◽  
Control Approach ◽  
Control Scheme ◽  
The Stability

This paper presents a new control approach for an underwater vehicle with a kinematically redundant thruster system. This control scheme is derived based on a fault-tolerant decomposition for thruster force allocation and a region control scheme for the tracking objective. Given a redundant thruster system, that is, six or more pairs of thrusters are used, the proposed redundancy resolution and region control scheme determine the number of thruster faults, as well as providing the reference thruster forces in order to keep the underwater vehicle within the desired region. The stability of the presented control law is proven in the sense of a Lyapunov function. Numerical simulations are performed with an omnidirectional underwater vehicle and the results of the proposed scheme illustrate the effectiveness in terms of optimizing the thruster forces.

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