scholarly journals Control Strategies for Multi-UAV Simultaneous Arrival under Communication Topology Changing

2018 ◽  
Vol 36 (3) ◽  
pp. 565-570
Author(s):  
Yanying Tan ◽  
Liang Xue ◽  
Yanning Zhang ◽  
Xiaoping Zhu
Keyword(s):  
Survival Rate ◽  
Spanning Tree ◽  
Control Strategies ◽  
Consensus Algorithm ◽  
Time Of Arrival ◽  
Node Failure ◽  
Directed Spanning Tree ◽  
Communication Topology ◽  
Simulation Results ◽  
Multi Uav

Aimed at changing in communication topology due to partial link/node failure in the battlefield, and for satisfying the weakest connectivity criteria of consensus algorithm, the strategy of judging in real time whether the communication topology among UAVs has a directed spanning tree or sub-tree and the strategy of acquiring the expected minimum partial link change suggestion for the topology containing a directed spanning tree again are designed. Based on the above strategies and selecting ETA (Estimated Time of Arrival) as coordinated variable, the consensus algorithm ensures that after some time all the members or part members of the UAVs arrive simultaneously. The strategy is put forword which the UAVS are controlled arriving simultaneously on the planed virtual sub-goal waypoints one by one along the flight path. Through the strategy, the UAVs fly together soon and arrive simultaneously at last. It is helpful to improve the survival rate of UAVs and preserve the communication connectivity of UAVs which is usually distance-dependent. The simulation results show that the above strategies are effective.

Pseudo Two-Hop Distributed Consensus Algorithm under Directed Topologies

2012 ◽  
Vol 591-593 ◽  
pp. 1599-1602 ◽  
Author(s):  
Huan Xin Peng ◽  
Wen Kai Wang
Keyword(s):  
Convergence Rate ◽  
Spectral Radius ◽  
Consensus Algorithm ◽  
Distributed Consensus ◽  
Convergence Conditions ◽  
Communication Topology ◽  
The Matrix ◽  
Convergence Performance ◽  
Simulation Results ◽  
Directed Topologies

In this paper, we propose the pseudo two-hop distributed consensus algorithm under directed communication topologies. The convergence performance of the pseudo two-hop distributed consensus algorithm under directed communication topologies are analyzed, and the convergence conditions for the pseudo two-hop distributed consensus algorithm are given. In particular, the convergence rate is determined by the spectral radius of the matrix depend on the communication topology. Finally, simulation results are provided to verify these analytical results.

scholarly journals Consensus of Multiagent Systems with Packet Losses and Communication Delays Using a Novel Control Protocol

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Zheping Yan ◽  
Di Wu ◽  
Wei Zhang ◽  
Yibo Liu
Keyword(s):  
Spanning Tree ◽  
Multiagent System ◽  
Matrix Theory ◽  
High Order ◽  
Communication Delays ◽  
Packet Losses ◽  
Control Protocol ◽  
Directed Spanning Tree ◽  
Communication Topology ◽  
Double Integrator

This paper studies the consensus problem of multiagent system with packet losses and communication delays under directed communication channels. Different from previous research results, a novel control protocol is proposed depending only on periodic sampling and transmitting data in order to be convenient for practical implementation. Due to the randomicity of transmission delays and packet losses, each agent updates its input value asynchronously at discrete time instants with synchronized time stamped information and evolves in continuous time. Consensus conditions for multiagent system consists of three typical dynamics including single integrator, double integrator, and high-order integrator that are all discussed in this paper. It is proved that, for single integrator agents and double integrator systems with only communication delays, consensusability can be ensured through stochastic matrix theory if the designed communication topology contains a directed spanning tree. While, for double integrator agents and high-order integrator agents with packet losses and communication delays, the interval system theory is introduced to prove the consensus of multiagent system under the condition that the designed communication topology is a directed spanning tree. Finally, simulations are carried out to validate the effectiveness of the proposed solutions.

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

Control of inverters in standalone andgrid-connected microgrid using different control strategies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vikash Gurugubelli ◽  
Arnab Ghosh
Keyword(s):  
Transient Response ◽  
Control Strategy ◽  
Control Strategies ◽  
Power Balance ◽  
Droop Control ◽  
Content Type ◽  
Simulink Simulation ◽  
Time Simulation ◽  
Simulation Results ◽  
First Time

Purpose The share of renewable energy sources (RESs) in the power system is increasing day by day. The RESs are intermittent, therefore maintaining the grid stability and power balance is very difficult. The purpose of this paper is to control the inverters in microgrid using different control strategies to maintain the system stability and power balance. Design/methodology/approach In this paper, different control strategies are implemented to the voltage source converter (VSC) to get the desired performance. The DQ control is a basic control strategy that is inherently present in the droop and virtual synchronous machine (VSM) control strategies. The droop and VSM control strategies are inspired by the conventional synchronous machine (SM). The main objective of this work is to design and implement the three aforementioned control strategies in microgrid. Findings The significant contributions of this work are: the detailed implementation of DQ control, droop control and VSM control strategies for VSC in both grid-connected mode and standalone mode is presented; the MATLAB/Simulink simulation results and comparative studies of the three aforementioned controllers are introduced first time in the proposed work; and the opal-RT digital real-time simulation results of the proposed VSM control show the superiority in transient response compared to the droop control strategy. Research limitations/implications In the power system, the power electronic-based power allowed by VSM is dominated by the conventional power which is generated from the traditional SM, and then the issues related to stability still need advance study. There are some differences between the SM and VSM characteristics, so the integration of VSM with the existing system still needs further study. Economical operation of VSM with hybrid storage is also one of the future scopes of this work. Originality/value The significant contributions of this work are: the detailed implementation of DQ control, droop control and VSM control strategies for VSC in both grid-connected mode and standalone mode is presented; the MATLAB/Simulink simulation results and comparative studies of the three aforementioned controllers are introduced first time in the proposed work; and the opal-RT digital real-time simulation results of the proposed VSM control show the superiority in transient response compared to the droop control strategy.

Multi-UAV Cooperative Task Planning for Border Patrol based on Hierarchical Optimization

2021 ◽  
Author(s):  
Hai-shi Liu ◽  
Yu-xuan Sun ◽  
Nan Pan ◽  
Qi-yong Chen ◽  
Xiao-jue Guo ◽  
...  
Keyword(s):  
Chaos Theory ◽  
Hierarchical Optimization ◽  
Border Patrol ◽  
Complex Environments ◽  
Environmental Model ◽  
Other Information ◽  
Aerial Vehicle ◽  
Scene Information ◽  
Simulation Results ◽  
Multi Uav

In order to improve the patrol efficiency of border patrol drones, based on unmanned aerial vehicle (UAV) border patrol missions in multiple complex environments, this article proposes a whale algorithm based on chaos theory to plan patrol missions for multiple drones. First, according to the terrain the corresponding environmental model is established for the topography and then solved in layers to obtain the number of drones and other information that each base needs to send to the patrol area. Further, the use of drones with cameras and other detection equipment to patrol the scene information and images extract and transfer to the terminal in real time, and further detect suspicious persons and vehicles on the screen. The final simulation results show that the proposed scheme can be effectively applied to the planning of multi-UAV coordinated missions for border patrol.

Formal Modeling and Analysis of Collaborative Humanoid Robotics

2019 ◽  
pp. 1086-1108
Author(s):  
Yujian Fu ◽  
Zhijiang Dong ◽  
Xudong He
Keyword(s):  
Petri Net ◽  
Control Strategies ◽  
Formal Modeling ◽  
Humanoid Robotics ◽  
Modeling And Analysis ◽  
Agent Based ◽  
Design And Implementation ◽  
Simulation Results ◽  
And Control ◽  
Successful Collaboration

A humanoid robot is inherently complex due to the heterogeneity of accessory devices and to the interactions of various interfaces, which will be exponentially increased in multiple robotics collaboration. Therefore, the design and implementation of multiple humanoid robotics (MHRs) remains a very challenging issue. It is known that formal methods provide a rigorous analysis of the complexity in both design of control and implementation of systems. This article presents an agent-based framework of formal modeling on the design of communication and control strategies of a team of autonomous robotics, to attain the specified tasks in a coordinated manner. To ensure a successful collaboration of multiple robotics, this formal agent-based framework captures behaviors in Petri Net models and specifies collaboration operations in four defined operations. To validate the framework, a non-trivial soccer bot set was implemented and simulation results were discussed.

scholarly journals Instantaneous Frequency Estimation Based on Modified Kalman Filter for Cone-Shaped Target

2020 ◽  
Vol 12 (17) ◽  
pp. 2766
Author(s):  
Ke Ren ◽  
Lan Du ◽  
Xiaofei Lu ◽  
Zhenyu Zhuo ◽  
Lu Li
Keyword(s):  
Kalman Filter ◽  
Survival Rate ◽  
Instantaneous Frequency ◽  
Estimation Method ◽  
Consensus Algorithm ◽  
Instantaneous Frequency Estimation ◽  
Time Frequency ◽  
Multicomponent Signals ◽  
Modified Kalman Filter ◽  
Trajectory Correction

The instantaneous frequency (IF) is a vital parameter for the analysis of non-stationary multicomponent signals, and plays an important role in space cone-shaped target recognition. For a cone-shaped target, IF estimation is not a trivial issue due to the proximity of the energy of the IF components, the intersections among different IF components, and the existence of noise. Compared with the general parameterized time-frequency (GPTF), the traditional Kalman filter can perform better when the energy of different signal components is close. Nevertheless, the traditional Kalman filter usually makes association mistakes at the intersections of IF components and is sensitive to the noise. In this paper, a novel IF estimation method based on modified Kalman filter (MKF) is proposed, in which the MKF is used to associate the intersecting IF trajectories obtained by the synchroextracting transform (SET). The core of MKF is the introduction of trajectory correction strategy in which a trajectory survival rate is defined to judge the occurrence of association mistakes. When the trajectory survival rate is below the predetermined threshold, it means that an association mistakes occurs, and then the new trajectories generated by the random sample consensus algorithm are used to correct the wrong associations timely. The trajectory correction strategy can effectively obviate the association mistakes caused by the intersections of IF components and the noise. The windowing technique is also used in the trajectory correction strategy to improve computational speed. The experimental results based on the electromagnetic computation data show that the proposed method is more robust and precise than the traditional Kalman filter. Moreover, the proposed method has great performance advantages compared with other methods (i.e., the multiridge detection, the ant colony optimization, and the GPTF methods) especially in the case of low signal noise ratio (SNR).

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