Browsing by Author "Xie, Guangming"

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Distributed Event-Triggered Circular Formation Control for Multiple Anonymous Mobile Robots With Order Preservation and Obstacle Avoidance
(2020) Xu, Peng; Li, Wenxiang; Tao, Jin; Dehmer, Matthias; Emmert-Streib, Frank; Xie, Guangming; Xu, Minyi; Zhou, Quan
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This article investigates circular formation control problems for a group of anonymous mobile robots in the plane, where all robots can converge asymptotically to a predefined circular orbit around a fixed target point without collision, and maintain any desired relative distances from their neighbors. Given the limited resources for communication and computation of robots, a distributed event-triggered method is firstly designed to reduce dependence on resources in multi-robot systems, where the controller's action is determined by whether the norm of the event-trigger function exceeds zero through continuous sampling. And then, to further minimize communications costs, a self-triggered strategy is proposed, which only uses discrete states sampled and sent by neighboring robots at their event instants. Furthermore, for the two proposed control laws, a Lyapunov functional is constructed, which allows sufficient stability conditions to be obtained on the circular formation for multi-robot systems. And at the same time, the controllers are proved to exclude Zeno behavior. At last, numerical simulation of controlling uniform and non-uniform circular formations by two control methods are conducted. Simulation results show that the designed controller can control all mobile robots to form either a uniform circular formation or a non-uniform circular formation while maintaining any desired relative distances between robots and guaranteeing that there is no collision during the whole evolution. One of the essential features of the proposed control methods is that they reduce the update rates of controllers and the communication frequency between robots. And also, the spatial order of robots is also preserved throughout the evaluation of the system without collision.
Distributed finite-time bipartite consensus of multi-agent systems via event-triggered control
(2020) Xu, Peng; Wang, Xinyu; Xie, Guangming; Tao, Jin; Xu, Minyi; Zhou, Quan
A4 Artikkeli konferenssijulkaisussa
This paper investigates a distributed finite-time event-triggered bipartite consensus control for multi-agent systems. Under scenarios of energy limitation, an event-triggered strategy coupled with a nonlinear distributed control protocol is proposed only relying on local information, where the controller only updates at triggered instants. We proved that when the antagonistic network contains a spanning tree, the event-triggered controller can drive all agents to reach consensus value with an identical magnitude but opposite signs. Moreover, both the convergence time depending on the initial state and the positive lower bound of inter-event times are achieved. Simulation results show that the proposed controller has better disturbance rejection properties and can achieve bipartite consensus faster compared to an asymptotic controller. Copyright (C) 2020 The Authors.
Distributed Self-triggered Circular Formation Control for Multi-robot Systems
(2020-07) Xu, Peng; Wang, Xinyu; Tao, Jin; Xie, Guangming; Xu, Minyi; Zhou, Quan
A4 Artikkeli konferenssijulkaisussa
This paper investigates circular formation control problems for multi-robot systems in the plane via a distributed self-triggered strategy. In scenarios of restricted energies, a distributed self-triggered protocol is designed for controlling multiple robots to converge asymptotically to a prescribed circular orbit around a fixed target. In particular, each robot maintains any desired relative angular distances during its rotation around the target. Besides, no collision among robots is taken place, since the spatial order of robots is preserved throughout the evolution. We prove that when the event-triggered condition is enforced during the whole process, the controllers only update with superior performance. Moreover, Zeno behavior can be ruled out. Numerical simulations demonstrate the feasibility and effectiveness of the theoretical results.
Fluid-Structure Interaction Simulation and Accurate Dynamic Modeling of Parachute Warhead System Based on Impact Point Prediction
(2021-07-26) Zhu, Hong; Sun, Qinglin; Tao, Jin; Tan, Panlong; Chen, Zengqiang; Dehmer, Matthias; Xie, Guangming
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
To predict a parachute-warhead system's dynamic characteristics and impact point, numerical methods are used to comprehensively predict the large deformations of the parachute during the opening process and the impact point of the system in the terminal landing phase. Fluid-structure interaction simulations based on the arbitrary Lagrangian-Eulerian method are used to study the Disk-Gap-Band parachute's inflation behavior and provide the parachute's aerodynamic parameters at steady state. Based on the obtained aerodynamic data, a nine-degree-of-freedom dynamic model of the parachute-warhead system was established, which was used to predict the landing area of the system by calculating the falling trajectory. Based on the established model, an online impact point prediction program was developed. Finally, the effectiveness and accuracy of the methods were verified by airdrop experiments. The results showed that the methods for the parachute-warhead system modeling during the inflation and terminal descent phases could effectively predict its dynamic characteristics, which could be further applied for precision airdrop missions.
A Generalized Predictive Control-Based Path Following Method for Parafoil Systems in Wind Environments
(2019-03-18) Tao, Jin; Dehmer, Matthias; Xie, Guangming; Zhou, Quan
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Parafoil systems represent flexible wing vehicles. In case a vehicle is flying at low altitude, it is well known that the vehicle is more susceptible to winds. Also, due to the nonlinear, large inertial existing within the system, traditional control methods, such as traditional proportional-integral-derivative (PID), cannot guarantee the quality of path following. Therefore, we here apply generalized predictive control (GPC)-based method for parafoil systems to follow the designed path for a better control effect. To achieve this, we first propose a novel modeling method based on computational fluid dynamics to build a dynamic model of the parafoil system in windy environments. Afterward, a guidance law is designed according to a hybrid approach that combines the cross track error and the line of sight. In addition, the path following controller is established by using GPC. Finally, we generate and interpret numerical results to demonstrate the feasibility of the horizontal path following method in windy environments by utilizing the semi-physical simulation platform. The achieved results show that the GPC controller achieves high precision path following. More precisely, it possesses a better anti-wind ability and tracking accuracy and, therefore, the method outperforms PID controller.
In-flight wind field identification and prediction of parafoil systems
(2020-03-01) Gao, Haitao; Tao, Jin; Dehmer, Matthias; Emmert-Streib, Frank; Sun, Qinglin; Chen, Zengqiang; Xie, Guangming; Zhou, Quan
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
The wind field is an essential factor that affects accurate homing and flare landing of parafoil systems. In order to obtain the ambient wind field during the descent of a parafoil system, a combination method of in-flight wind field identification and prediction is proposed. First, a wind identification method only using global position system information is derived based on the flight dynamics of parafoil systems. Then a wind field prediction model is constructed using the atmospheric dynamics, and the low-altitude wind field is predicted based on the identified wind field of high-altitude. Finally, simulations of wind field identification and prediction are conducted. The results demonstrate that the proposed method can identify the wind fields precisely and also predict the wind fields reasonably. This method can potentially be applied in practical parafoil systems to provide wind field information for homing tasks.
LADRC-based Path Following Control for Cylindrical Drilling Platform Towing System
(2020-11-06) Tao, Jin; Du, Lei; Sun, Hao; Sun, Qinglin; Xie, Guangming; Zhou, Quan
A4 Artikkeli konferenssijulkaisussa
The towing process is the precondition to put a cylindrical drilling platform into use, which is saturated with risk due to the complexity of the towing environment, towing maneuvering, and the sudden and severity of accidents. Therefore, to control the cylindrical drilling platform towing system safely following a predefined course to reach the target see area becomes increasingly important. For environmental disturbances caused by wind and currents changing with time, a linear adaptive-disturbance-rejection-control (LADRC) based path following control method for cylindrical drilling platform towing system is proposed. Firstly, on the basis of both the mathematical modeling group model and the catenary model, three degrees of freedom nonlinear model of the cylindrical drilling platform towing system is built to obtain its real-time motion state. Then, a LADRC controller based on a two-dimensional trajectory tracking guidance law is designed for real-time path following control. Finally, simulation experiments of the path following control for the cylindrical drilling platform towing system is conducted. The results illustrate that the LADRC can effectively resist influences of the environmental disturbances and has a better path following performances than the traditional proportional-integral-derivative (PID) controller.
Observer-based event-triggered circle formation control for first- And second-order multiagent systems
(2020-03-24) Xu, Peng; Xie, Guangming; Tao, Jin; Xu, Minyi; Zhou, Quan
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This paper proposes an observer-based event-triggered algorithm to solve circle formation control problems for both first- and second-order multiagent systems, where the communication topology is modeled by a spanning tree-based directed graph with limited resources. In particular, the observation-based event-triggering mechanism is used to reduce the update frequency of the controller, and the triggering time depends on the norm of the state function and the trigger threshold of measurement errors. The analysis shows that sufficient conditions are established for achieving the desired circle formation, while there exists at least one agent for which the next interevent interval is strictly positive. Numerical simulations of both first- and second-order multiagent systems are also given to demonstrate the effectiveness of the proposed control laws.
Path following control for towing system of cylindrical drilling platform in presence of disturbances and uncertainties
(2019) Tao, Jin; Du, Lei; Dehmer, Matthias; Wen, Yuanqiao; Xie, Guangming; Zhou, Quan
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Towing is a critical process to deploy a cylindrical drilling platform. However, the towing process faces a great variety of risks from a complex nautical environment, the dynamics in towing and maneuvering, to unexpected events. Therefore, safely navigating the towing system following a planned route to a target sea area is essential. To tackle the time-varying disturbances induced by wind, current and system parametric uncertainties, a path following control method for a towing system of cylindrical drilling platform is designed based on linear active disturbance rejection control. By utilizing Maneuvering Modeling Group model as well as a catenary model, we develop a three degree-of-freedom dynamic mathematical model of the towing system under external environmental disturbances and internal uncertainties. Furthermore, we design a linear active disturbance rejection control path following controller for real-time tracking error correction based on a guidance method combining cross-track error and parallax. Finally, the path following performance of the towing system is evaluated in a simulation environment under various disturbances and internal uncertainties, where the corresponding tracking error is analyzed. The results show that the linear active disturbance rejection control performs well under both the external disturbance and inherent uncertainties, and better satisfy the tracking performance criteria than a traditional proportional–integral–derivative controller.
Pull-based distributed event-triggered circle formation control for multi-agent systems with directed topologies
(2019-12-01) Xu, Peng; Zhao, Hongfa; Xie, Guangming; Tao, Jin; Xu, Minyi
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This paper investigates a circle formation control problem for multi-agent systems with directed topologies via pull-based distributed event-triggered control principles. Firstly, for scenarios of continuous communication, a pull-based distributed event-triggered principle is proposed. It is proved that if the communication topology is irreducible and has a directed spanning tree, the event-triggered coupling continuous communication can lead multiple agents to form a desired circle formation. Then, the results are extended to discontinuous communication scenarios, where all the agents use a model of their neighborhoods to generate self-triggered instants without monitoring continuously, update the local controller here, and if necessary, local broadcast information based on the adopted control inputs to neighboring agents. In addition, Zeno behavior can be excluded during the whole process. Finally, numerical simulation results are given to demonstrate the effectiveness of the proposed circle formation control methods.
A triboelectric-based artificial whisker for reactive obstacle avoidance and local mapping
(2021-07-10) Xu, Peng; Wang, Xinyu; Wang, Siyuan; Chen, Tianyu; Liu, Jianhua; Zheng, Jiaxi; Li, Wenxiang; Xu, Minyi; Tao, Jin; Xie, Guangming
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Since designing efficient tactile sensors for autonomous robots is still a challenge, this paper proposes a perceptual system based on a bioinspired triboelectric whisker sensor (TWS) that is aimed at reactive obstacle avoidance and local mapping in unknown environments. The proposed TWS is based on a triboelectric nanogenerator (TENG) and mimics the structure of rat whisker follicles. It operates to generate an output voltage via triboelectrification and electrostatic induction between the PTFE pellet and copper films (0.3mm thickness), where a forced whisker shaft displaces a PTFE pellet (10mm diameter). With the help of a biologically inspired structural design, the artificial whisker sensor can sense the contact position and approximate the external stimulation area, particularly in a dark environment. To highlight this sensor's applicability and scalability, we demonstrate different functions, such as controlling LED lights, reactive obstacle avoidance, and local mapping of autonomous surface vehicles. The results show that the proposed TWS can be used as a tactile sensor for reactive obstacle avoidance and local mapping in robotics.