scholarly journals Simulation-based usability testing of some tracking controllers for underactuated underwater vehicles using simplified criteria

2021 ◽  
Author(s):  
Przemyslaw Herman
Keyword(s):  
Experimental Validation ◽  
Control Strategies ◽  
Underwater Vehicles ◽  
Control Algorithms ◽  
Simulation Studies ◽  
Numerical Tests ◽  
Control Schemes ◽  
Simulation Based ◽  
Tracking Controllers ◽  
Selection Of

AbstractThis paper proposes a method for the preliminary verification of known control algorithms designed for tracking the desired trajectory of underactuated underwater vehicles. It is based on simplified criteria for the selection of suitable controllers. Moreover, a certain method for the selection of controller parameters is indicated, which can be effective in the initial analysis of the suitability of selected control schemes. In order to demonstrate the possible application of the described approach, several control strategies known from the literature were selected and numerical tests for them were performed for two 3 DOF models of underwater vehicles with different dynamics. The method given here can be useful for simulation studies at the stage of controller selection without its experimental validation.

scholarly journals Numerical Test of Several Controllers for Underactuated Underwater Vehicles

2020 ◽  
Vol 10 (22) ◽  
pp. 8292
Author(s):  
Przemyslaw Herman
Keyword(s):  
Control Algorithm ◽  
Control Strategies ◽  
Numerical Test ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Control Algorithms ◽  
Dynamics Model ◽  
Numerical Tests ◽  
Control Schemes ◽  
Testing Algorithm

This work is devoted to preliminary numerical tests of selected control strategies of underwater vehicles in the absence of a force applied to the side. The aim was to test the effectiveness of control algorithms for underwater vehicle models considered to be underactuated. Initially, the testing algorithm is used to obtain some information about the dynamics model. Several well-known control schemes for two underwater vehicles for two desired trajectories were selected and tested. The simulations made for the planar 3-DOF model of two underwater vehicles show the performance that can be achieved with each control algorithm according to the assumptions made.

A Simulation Methodology for Conducting Unbiased and Reliable Evaluation of MANET Communication Protocols in Disaster Scenarios

2018 ◽  
pp. 106-143 ◽  
Author(s):  
José Manuel García-Campos ◽  
Daniel Gutiérrez ◽  
Jesús Sánchez-García ◽  
Sergio Toral Marn
Keyword(s):  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Communication Protocol ◽  
Communication Protocols ◽  
Simulation Studies ◽  
Simulation Based ◽  
Relevant Task ◽  
Emergency Scenarios ◽  
Simulation Parameters ◽  
Selection Of

The need for a Mobile Ad-Hoc Network (MANET) in environments where there is a lack of communication infrastructure, such as disaster or emergency scenarios, is critical to save lives. MANETs can be used as an alternative network that solves the problem of communications. The selection of an appropriate MANET communication protocol is crucial for the good performance of the whole network. Due to the great variety of communication protocols available for MANETs such as routing and broadcasting protocols, the selection of the most suitable one for disaster scenarios is a relevant task. Routing protocols and broadcasting algorithms are normally evaluated and compared using simulation-based studies. However, conducting reliable and repeatable simulation studies is not a trivial task because many simulation parameters should be correctly configured. In this paper, we propose a methodology for conducting reliable simulations of MANET broadcasting algorithms in disaster scenarios. The proposed methodology is focused on the source nodes selection based on different metrics.

scholarly journals Performance Analysis of Three-Phase DVR with Modified Switching Band Controller

2019 ◽  
Vol 9 (1) ◽  
pp. 934-941
Keyword(s):  
Performance Analysis ◽  
Series Resistance ◽  
Control Strategies ◽  
Switching Control ◽  
Simulation Studies ◽  
Switching Loss ◽  
Three Phase ◽  
Capacitor Storage ◽  
Selection Of

This paper deals with the mitigation of voltage related PQ issues by using three phase neutral clamped VSI topology is used to realize the DVR and the design of DVR for the selection of suitable interface inductor, DC capacitor storage series resistance and the capacitance. Here three-phase four wire DVR with modified switching band controller topology is proposed, which overcome the frequent band violation, poor controllability and heavy filter currents, and compared to three-phase four wire DVR with conventional filter topology. The compensation capability of the proposed topology is analyzed based on simulation studies and corresponding results are compared with different switching control strategies. The consequent merits and demerits switching loss in VSI, ripple in compensated load voltages and error between reference injected voltages and actual injected voltages in different switching control strategies are discussed.

Towards a simulation-benchmark for evaluating respirometry-based control strategies

1998 ◽  
Vol 37 (12) ◽  
pp. 219-226 ◽  
Author(s):  
Henri Spanjers ◽  
Peter Vanrolleghem ◽  
Khanh Nguyen ◽  
Henk Vanhooren ◽  
Gilles G. Patry
Keyword(s):  
Simulation Model ◽  
Control Strategy ◽  
State Of The Art ◽  
Control Strategies ◽  
Test Procedure ◽  
Full Scale ◽  
Simulation Studies ◽  
Convenient Means ◽  
Simulation Based ◽  
Simulation Results

Many respirometry-based control strategies have been proposed in the literature but few successful practical implementations or even simulation-based evaluations have been reported. The state-of-the-art provides insufficient justification for the development of a how-to-do procedure for such control strategies in full scale. It is, therefore, expected that carefully conducted simulation studies will greatly support the evaluation of proposed strategies and, eventually, the implementation in practice. These studies should be based on a rigorous methodology including simulation model, plant layout, controller and test procedure. This paper describes the development of such a methodology, termed “benchmark”. The benchmark is evaluated on the basis of a respirometry-based control strategy from the literature. Some simulation results are shown and modifications to the strategy imperative to the implementation in the benchmark are discussed. It is concluded that the benchmark provides a convenient means to perform a number of tests with the implemented control strategy. The benchmark should be further developed and tested.

scholarly journals pH-Based Control Strategies for the Nitrification of High-Ammonium Wastewaters

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 319
Author(s):  
Ignatius Leopoldus van Rooyen ◽  
Hendrik Gideon Brink ◽  
Willie Nicol
Keyword(s):  
Reaction Rate ◽  
Control Strategies ◽  
Environmental Issues ◽  
Control Algorithms ◽  
Maximum Reaction Rate ◽  
Tank Reactor ◽  
Industrial Sectors ◽  
Maximum Reaction ◽  
Control Schemes ◽  
Continuously Stirred Tank Reactor

Aquatic nitrogen pollution is one of the most urgent environmental issues requiring prevention and mitigation. Large quantities of high-ammonium wastewaters are generated by several industrial sectors, such as fertilizer and anaerobic-digestion plants. Nitrification of these wastewaters is commonly carried out, either to remove nitrogen or produce liquid fertilizers. Standard control methodologies for the efficient nitrification of high-ammonium wastewaters to produce liquid fertilizers have not yet been established and are still within their early stages of development. In this paper, novel pH-based control algorithms are presented that maintain operation at the microbial maximum reaction rate (υmax) in batch and continuous reactors. Complete conversion of ammonium to nitrate was achieved in a batch setup, and a conversion of 93% (±1%) was achieved in a continuously-stirred-tank-reactor. The unparalleled performance and affordability of the control schemes proposed offer a steppingstone to the future of sustainable fertilizer production.

scholarly journals Autonomous Underwater Vehicles and Field of View in Underwater Operations

2021 ◽  
Vol 9 (3) ◽  
pp. 277
Author(s):  
Isaac Segovia Ramírez ◽  
Pedro José Bernalte Sánchez ◽  
Mayorkinos Papaelias ◽  
Fausto Pedro García Márquez
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Field Of View ◽  
Guidance System ◽  
Control Algorithms ◽  
Deep Waters ◽  
Underwater Cameras ◽  
Optimal Resolution ◽  
Acquisition Processes ◽  
And Control

Submarine inspections and surveys require underwater vehicles to operate in deep waters efficiently, safely and reliably. Autonomous Underwater Vehicles employing advanced navigation and control systems present several advantages. Robust control algorithms and novel improvements in positioning and navigation are needed to optimize underwater operations. This paper proposes a new general formulation of this problem together with a basic approach for the management of deep underwater operations. This approach considers the field of view and the operational requirements as a fundamental input in the development of the trajectory in the autonomous guidance system. The constraints and involved variables are also defined, providing more accurate modelling compared with traditional formulations of the positioning system. Different case studies are presented based on commercial underwater cameras/sonars, analysing the influence of the main variables in the measurement process to obtain optimal resolution results. The application of this approach in autonomous underwater operations ensures suitable data acquisition processes according to the payload installed onboard.

scholarly journals Zero-Width Quasi-Sliding Mode Band in the Presence of Non-Matched Uncertainties

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3011
Author(s):  
Paweł Latosiński ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode Control ◽  
Discrete Time ◽  
Sliding Mode ◽  
Control Strategies ◽  
Relative Degree ◽  
Band Width ◽  
Representative Point ◽  
Mode Control ◽  
Sliding Motion ◽  
Selection Of

Sliding mode control strategies are well known for ensuring robustness of the system with respect to disturbance and model uncertainties. For continuous-time plants, they achieve this property by confining the system state to a particular hyperplane in the state space. Contrary to this, discrete-time sliding mode control (DSMC) strategies only drive the system representative point to a certain vicinity of that hyperplane. In established literature on DSMC, the width of this vicinity has always been strictly greater than zero in the presence of uncertainties. Thus, ideal sliding motion was considered impossible for discrete-time systems. In this paper, a new approach to DSMC design is presented with the aim of driving the system representative point exactly onto the sliding hyperplane even in the presence of uncertainties. As a result, the quasi-sliding mode band width is effectively reduced to zero and ideal discrete-time sliding motion is ensured. This is achieved with the proper selection of the sliding hyperplane, using the unique properties of relative degree two sliding variables. It is further demonstrated that, even in cases where selection of a relative degree two sliding variable is impossible, one can use the proposed technique to significantly reduce the quasi-sliding mode band width.

Numerical simulation studies of Cs3Bi2I9 perovskite solar device with optimal selection of electron and hole transport layers

Optik ◽  
2021 ◽  
Vol 231 ◽  
pp. 166417 ◽  
Author(s):  
Md Tohidul Islam ◽  
Md Rafsun Jani ◽  
Kazi Md Shorowordi ◽  
Zameer Hoque ◽  
Ali Mucteba Gokcek ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Hole Transport ◽  
Optimal Selection ◽  
Simulation Studies ◽  
Hole Transport Layers ◽  
Selection Of

A Survey on Brachiation Robots: An Energy-Based Review

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Sibyla Andreuchetti ◽  
Vinícius M. Oliveira ◽  
Toshio Fukuda
Keyword(s):  
Special Class ◽  
Control Strategies ◽  
Underactuated Systems ◽  
Decision Variable ◽  
Robot Dynamics ◽  
Technical Literature ◽  
Control Schemes

SUMMARY Many different control schemes have been proposed in the technical literature to control the special class of underactuated systems, the- so-called brachiation robots. However, most of these schemes are limited with regard to the method by which the robot executes the brachiation movement. Moreover, many of these control strategies do not take into account the energy of the system as a decision variable. To observe the behavior of the system’s, energy is very important for a better understanding of the robot dynamics while performing the motion. This paper discusses a variety of energy-based strategies to better understand how the system’s energy may influence the type of motion (under-swing or overhand) the robot should perform.

scholarly journals Outlier Detection at the Parcel-Level in Wheat and Rapeseed Crops Using Multispectral and SAR Time Series

2021 ◽  
Vol 13 (5) ◽  
pp. 956
Author(s):  
Florian Mouret ◽  
Mohanad Albughdadi ◽  
Sylvie Duthoit ◽  
Denis Kouamé ◽  
Guillaume Rieu ◽  
...  
Keyword(s):  
Outlier Detection ◽  
Experimental Validation ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Multispectral Images ◽  
Vegetation Indexes ◽  
Crop Development ◽  
Different Types ◽  
Selection Of ◽  
Sentinel 2

This paper studies the detection of anomalous crop development at the parcel-level based on an unsupervised outlier detection technique. The experimental validation is conducted on rapeseed and wheat parcels located in Beauce (France). The proposed methodology consists of four sequential steps: (1) preprocessing of synthetic aperture radar (SAR) and multispectral images acquired using Sentinel-1 and Sentinel-2 satellites, (2) extraction of SAR and multispectral pixel-level features, (3) computation of parcel-level features using zonal statistics and (4) outlier detection. The different types of anomalies that can affect the studied crops are analyzed and described. The different factors that can influence the outlier detection results are investigated with a particular attention devoted to the synergy between Sentinel-1 and Sentinel-2 data. Overall, the best performance is obtained when using jointly a selection of Sentinel-1 and Sentinel-2 features with the isolation forest algorithm. The selected features are co-polarized (VV) and cross-polarized (VH) backscattering coefficients for Sentinel-1 and five Vegetation Indexes for Sentinel-2 (among us, the Normalized Difference Vegetation Index and two variants of the Normalized Difference Water). When using these features with an outlier ratio of 10%, the percentage of detected true positives (i.e., crop anomalies) is equal to 94.1% for rapeseed parcels and 95.5% for wheat parcels.

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