Incidence Control Units Selection Scheme to Enhance the Stability of Multiple UAVs Network

2022 ◽  
pp. 1-1
Author(s):  
Jian Cui ◽  
Lei Wang ◽  
Bo Hu ◽  
Shanzhi Chen
Keyword(s):  
Selection Scheme ◽  
Multiple Uavs ◽  
Control Units ◽  
The Stability

An Identifier-Selection Method for Expressway Network Based on Toll Collection Accuracy of Multi-Path

2013 ◽  
Vol 321-324 ◽  
pp. 2260-2264
Author(s):  
Dong Bin Xu ◽  
Shu Zhen Shi ◽  
Hao Zhang
Keyword(s):  
Network Model ◽  
Selection Method ◽  
Basic Information ◽  
Selection Probability ◽  
Selection Scheme ◽  
Running Time ◽  
Candidate Strategy ◽  
Selection For ◽  
Toll Collection ◽  
The Stability

A method for identifier-selection in expressway network is proposed based on toll collection accuracy of multi-path. Using basic information of the expressway network, the network model is built. Toll collection accuracy of the model is computed by the following steps: selection for competitive and valid paths, calculation for selection probability, toll calculation and calculation for toll collection accuracy. Through multi-period and multi-candidate strategy, the identifier-selection scheme is adopted to improve the stability and save the running time. The results verify the rationality and practicality of the method.

Parametric Identification of Vehicle’s Vertical Dynamics Using Vector Autoregressive Moving Average Models

2006 ◽  
Author(s):  
Dimitris V. Koulocheris ◽  
Vasilis K. Dertimanis
Keyword(s):  
Ride Comfort ◽  
Moving Average ◽  
Estimation Procedure ◽  
Parametric Identification ◽  
Practical Implementation ◽  
Vertical Acceleration ◽  
Vector Autoregressive ◽  
Control Units ◽  
Conflicting Objectives ◽  
The Stability

The assessment of vertical dynamics in modern ground vehicles is a difficult task with crucial importance, as it appears to be possessed by a number of conflicting objectives, such as ride comfort and stability. Thus, the effective use of possible control units is depended by the successful description of the vertical performance. The aim of this study is to provide a closed description of vehicles’ vertical dynamics using VARMA models, which are estimated by means of a novel, hybrid optimization algorithm and a corresponding estimation procedure. The hybrid algorithm interconnects the diverse characteristics of its deterministic and stochastic counterparts, while the estimation procedure assures the stability and invertibility requirements in the resulted models. For the practical implementation of the above, a five dimensional VARMA model is used for the description of a passenger vehicle, through the acquisition of noise–corrupted vertical acceleration measurements.

scholarly journals Fuzzy type 1 PID controllers design for TCP/AQM wireless networks

2021 ◽  
Vol 21 (1) ◽  
pp. 118
Author(s):  
Manal Kadhim Oudah ◽  
Mohammed Qasim Sulttan ◽  
Salam Waley Shneen
Keyword(s):  
Fuzzy Logic ◽  
Wireless Networks ◽  
Pid Controllers ◽  
Logic Control ◽  
Internet Users ◽  
Control Units ◽  
Communication Time ◽  
The Stability ◽  
The Impact

<p><span>The search of FLC_PID controller for TCP/AQM Wireless Networks, to deal with congestion for Internet users and to get good performance and capabilities of TCP / IP networks. Neglect of controlling the network delay and the number of continuous users that leads to a problem in the transmission process. Recently, automatic control units are adapted to solve this problem with the difficulty of controlling congestion in the presence of wireless links. This modest research presents one of the traditional PID controller methods with fuzzy logic so that wireless networks and congestion can be controlled by various configurations. The proposed methods were simulated with the required comparisons in the adoption of nonlinear systems to determine the best performance and it was found that the use of the Fuzzy logic control can achieve the best performance (reducing the delay time of delivering packets and packets loss). The simulation of the current work shows through its results the possibility of controlling the behavior of the system and through testing the balance when changed with time delay through the impact of communication time and its relationship with the stability of the work of the system.</span></p>

scholarly journals A standard sample determination method for the testing of smoke detectors and its application research

2020 ◽  
Vol 185 ◽  
pp. 02035
Author(s):  
Tingting Wang ◽  
Guoping Wu ◽  
Pei Zhang ◽  
Dake Zhang
Keyword(s):  
Ionization Chamber ◽  
Standard Sample ◽  
Sample Selection ◽  
Difficult Problem ◽  
Application Research ◽  
Standard Samples ◽  
Selection Scheme ◽  
Before And After ◽  
Smoke Detectors ◽  
The Stability

The stability of the standard sample plays a key role in the testing of the smoke detectors. A scientific and effective standard sample selection scheme is proposed in this paper. The repeatability and uniformity of the tested samples are evaluated before and after the environmental acceleration testing, and the most stable standard sample is obtained. At the same time, this paper explores the new application of the standard sample, which can be used in the calibration of the measuring ionization chamber (MIC). This work can greatly reduce the selection time and provide the standard samples for the laboratory of the smoke detectors testing which is scientific and reliable. At the same time, the difficult problem of the calibration of the measuring ionization chamber (MIC) is solved here.

scholarly journals Size and structure of the Mediterranean medicinal leech, Hirudo verbana populations inhabiting wetlands around Lake Eğirdir, Turkey

2021 ◽  
Vol 38 (4) ◽  
pp. 437-447
Author(s):  
Mustafa Ceylan ◽  
Osman Çetinkaya
Keyword(s):  
Population Size ◽  
Body Length ◽  
Conservation Status ◽  
Medicinal Leech ◽  
Age Classes ◽  
Control Units ◽  
Hirudo Verbana ◽  
The Mediterranean ◽  
The Stability ◽  
Size And Structure

In the present study size and structure of the Mediterranean medicinal leech (Hirudo verbana Carena, 1820) populations inhabiting wetlands around Lake Eğirdir (Turkey) were investigated. Population size was estimated by removal methods, age classes were estimated for the first time in leeches (Hirudinea) using “Modal Progression Analysis” of body length frequencies using Bhattacharya's method. The population size and biomass of medicinal leeches around Lake Eğirdir were estimated to be 1,562,696 ± 805,613 leeches and 467.26 ± 172.91 kg, respectively. Three age classes were identified; the age group of 0+ was dominant with 78.6%. While 89.9% of the individuals weighed less than 1 g, whereas the broodstock was estimated to represent only 7%. Body weight, body length and condition factor were found to be 0.52 ± 1.19 g, 4.5 ± 2.4 cm and 0.620 ± 0.123, respectively. This study reveals that the population size of H. verbana in the wetlands around Lake Eğirdir is relatively well preserved and there is no significant threat to the sustainability of the exploitation of the medicinal leech populations. It is concluded that the stability of the lake's water budget, the variety and abundance of the host in the undamaged wetlands, the socioeconomic structure of the leech collectors, the sales policies, and the effective activities of conservation and control units might affect conservation status of the medicinal leech populations inhabiting wetlands around Lake Eğirdir.

scholarly journals Design and Stability Analysis of Uncertain Networked Predictive Control Systems with Multiple Forward Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hongbo Song
Keyword(s):  
Stability Analysis ◽  
Control Systems ◽  
Predictive Control ◽  
Uncertain Systems ◽  
Closed Loop ◽  
Control Performance ◽  
Selection Scheme ◽  
Signal Selection ◽  
Networked Predictive Control ◽  
The Stability

This paper is concerned with the design and stability of networked predictive control for uncertain systems with multiple forward channels. The delays and packet dropouts are distributed such that the classic networked predictive control (NPC) needs modifications to be implemented. An improved control signal selection scheme with distributed prediction length is proposed to increase the prediction accuracy and hence achieve better control performance. Moreover, stability analysis results are obtained for both constant and random cases. Interestingly, it is shown that the stability of the closed-loop NPC system is not related to the distributed delays when they are constant and the system model is accurate. Finally, a two-axis milling machine example is given to illustrate the effectiveness of the proposed method.

scholarly journals An Improved UAV-PHD Filter-Based Trajectory Tracking Algorithm for Multi-UAVs in Future 5G IoT Scenarios

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1188 ◽  
Author(s):  
Tao Tang ◽  
Tao Hong ◽  
Haohui Hong ◽  
Senyuan Ji ◽  
Shahid Mumtaz ◽  
...  
Keyword(s):  
Trajectory Tracking ◽  
Detection Algorithm ◽  
Evaluation Indicator ◽  
Multiple Uavs ◽  
Target Intensity ◽  
Network Communications ◽  
Machine Type Communication ◽  
Core Service ◽  
The Stability ◽  
Emergency Detection

The 5G cellular network is expected to provide core service platform for the expanded Internet of Things (IoT) by supporting enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low latency communications (URLLC). Unmanned aerial vehicles (UAVs), also known as drones, provide civil, commercial, and government services in various fields. Particularly in a 5G IoT scenario, UAV-aided network communications will fulfill an increasingly important role and will require the tracking of multiple UAV targets. As UAVs move quickly, maintaining the stability of the communication connection in 5G will be a challenge. Therefore, it is necessary to track the trajectory of UAVs. At present, the GM-PHD filter has a problem that the new target intensity must be known, and it cannot obtain the moving target trajectory and the influence of the clutter is likely to cause false alarm. A UAV-PHD filter is proposed in this work to improve the traditional GM-PHD filter by applying machine learning to the emergency detection and trajectory tracking of UAV targets. An out-of-sight detection algorithm for multiple UAVs is then presented to improve tracking performance. The method is assessed by simulation using MATLAB, and OSPA distance is utilized as an evaluation indicator. The simulation results illustrate that the proposed method can be applied to the tracking of multiple UAV targets in future 5G-IoT scenarios, and the performance is superior to the traditional GM-PHD filter.

scholarly journals Adaptive Robust Trajectory Tracking Control of Multiple Quad-Rotor UAVs with Parametric Uncertainties and Disturbances

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2401
Author(s):  
Yasir Mehmood ◽  
Jawad Aslam ◽  
Nasim Ullah ◽  
Md. Shahariar Chowdhury ◽  
Kuaanan Techato ◽  
...  
Keyword(s):  
Trajectory Tracking ◽  
Control Method ◽  
Controller Design ◽  
Sliding Mode ◽  
Parametric Uncertainties ◽  
Trajectory Tracking Control ◽  
Multiple Uavs ◽  
Control Schemes ◽  
Robust Adaptive ◽  
The Stability

Recently, formation flying of multiple unmanned aerial vehicles (UAVs) found numerous applications in various areas such as surveillance, industrial automation and disaster management. The accuracy and reliability for performing group tasks by multiple UAVs is highly dependent on the applied control strategy. The formation and trajectories of multiple UAVs are governed by two separate controllers, namely formation and trajectory tracking controllers respectively. In presence of environmental effects, disturbances due to wind and parametric uncertainties, the controller design process is a challenging task. This article proposes a robust adaptive formation and trajectory tacking control of multiple quad-rotor UAVs using super twisting sliding mode control method. In the proposed design, Lyapunov function-based adaptive disturbance estimators are used to compensate for the effects of external disturbances and parametric uncertainties. The stability of the proposed controllers is guaranteed using Lyapunov theorems. Two variants of the control schemes, namely fixed gain super twisting SMC (STSMC) and adaptive super twisting SMC (ASTSMC) are tested using numerical simulations performed in MATLAB/Simulink. From the results presented, it is verified that in presence of disturbances, the proposed ASTSMC controller exhibits enhanced robustness as compared to the fixed gain STSMC.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Sign in / Sign up

Export Citation Format

Share Document