Robust Maneuvering Control for Marine Vehicles Under Uncertain Ocean Currents

2013 ◽  
Author(s):  
Qingmin Huang ◽  
Ye-Hwa Chen ◽  
Xin Nie
Keyword(s):  
Ocean Currents ◽  
Design Parameters ◽  
Fast Time ◽  
State Transformation ◽  
Marine Vehicles ◽  
Control Scheme ◽  
Uniform Ultimate Boundedness ◽  
Stability Ball ◽  
Marine Vehicle ◽  
Structure Properties

We consider the problem of tracking a desired trajectory with a desired velocity for a marine vehicle. There are possibly fast time-varying uncertainties which may exist in the model, the inputs, the ocean currents, as well as environment disturbances. Based on the possible bound of the uncertainties and some structure properties the marine vehicle are met, a state transformation is made to the dynamics of error of the marine vehicle. A robust control scheme is proposed which renders the transformed system practically stable. A proof shows that the original uncertain marine vehicle under this control will also be practically stable. Furthermore, the uniform ultimate boundedness ball and uniform stability ball of the marine vehicle can be made arbitrarily small by suitable choice of the design parameters.

Optimal Parameter Selection for Constraint-Following Control for Mechanical Systems Based on Stackelberg Game

2021 ◽  
Author(s):  
Qinqin Sun ◽  
Xiuye Wang ◽  
Guolai Yang ◽  
Ye-Hwa Chen ◽  
Fai Ma
Keyword(s):  
Stackelberg Game ◽  
Optimal Parameter ◽  
Mechanical Systems ◽  
Parameter Selection ◽  
Design Parameters ◽  
Fast Time ◽  
Control Cost ◽  
Stackelberg Strategy ◽  
Control Scheme ◽  
Unique Parameter

Abstract This paper proposes an optimal parameter design of control scheme for mechanical systems by adopting the Stackelberg game theory. The goal of the control is to drive the mechanical system to follow the prescribed constraints. The system uncertainty is (possibly fast) time-varying and bounded. A β-measure is defined to gauge the performance. A robust control is proposed to render the β-measure uniformly ultimately bounded. This control scheme is based on feasible design parameters (i.e., parameters within prescribed range), whose choice may not be unique. For optimal (unique) parameter selection, a Stackelberg game is formulated. By taking the control design parameters as the players, for each player, a cost function is built with the consideration of the performance cost, the time cost and the control cost. To follow, the Stackelberg strategy is then carried out via backward induction, which results in the choice of the optimal parameters.

Phase Change Materials - From Structures to Kinetics

2006 ◽  
Vol 918 ◽  
Author(s):  
Matthias Wuttig ◽  
Wojciech Welnic ◽  
Ralf Detemple ◽  
Henning Dieker ◽  
Johannes Kalb ◽  
...  
Keyword(s):  
Phase Change ◽  
Crystalline State ◽  
Phase Change Materials ◽  
Amorphous State ◽  
Structural Difference ◽  
Fast Time ◽  
Optical Contrast ◽  
Fast Time Scale ◽  
Kinetics Of ◽  
Structure Properties

AbstractPhase change materials possess a unique combination of properties which include a pronounced property contrast between the amorphous and crystalline state, i.e. a high electrical and optical contrast. In particular the latter observation is indicative for a considerable structural difference between the amorphous and crystalline state. At the same time the crystallization of the amorphous state proceeds on a fast time scale. This raises the question how structure, properties and kinetics are related in phase change alloys. It will be demonstrated that only a small group of covalent semiconductors with octahedral-like coordination has the required property combination. This is related to their thermodynamic properties which govern the kinetics of crystallization.

Recurrent Higher Order Neural Network Control for Output Trajectory Tracking with Neural Observers and Constrained Inputs

2010 ◽  
pp. 286-311 ◽  
Author(s):  
Luis J. Ricalde ◽  
Edgar N. Sanchez ◽  
Alma Y. Alanis
Keyword(s):  
Neural Network ◽  
Tracking Error ◽  
Network Control ◽  
Design Parameters ◽  
The Neural Network ◽  
Control Scheme ◽  
Output Trajectory ◽  
Error Dynamics ◽  
Adaptation Law ◽  
Constrained Inputs

This Chapter presents the design of an adaptive recurrent neural observer-controller scheme for nonlinear systems whose model is assumed to be unknown and with constrained inputs. The control scheme is composed of a neural observer based on Recurrent High Order Neural Networks which builds the state vector of the unknown plant dynamics and a learning adaptation law for the neural network weights for both the observer and identifier. These laws are obtained via control Lyapunov functions. Then, a control law, which stabilizes the tracking error dynamics is developed using the Lyapunov and the inverse optimal control methodologies . Tracking error boundedness is established as a function of design parameters.

A Novel Autonomous Docking Method of Unmanned Marine Vehicle Based on Manipulator

2013 ◽  
Vol 364 ◽  
pp. 370-374
Author(s):  
Jin Lei Chen ◽  
Yuan Dai ◽  
Zhong Qiang Zheng ◽  
Zong Yu Chang ◽  
Wen Dai ◽  
...  
Keyword(s):  
Data Exchange ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Kinematics Analysis ◽  
Marine Vehicles ◽  
Docking Method ◽  
Stability And Accuracy ◽  
Marine Vehicle ◽  
Limited Duration ◽  
Autonomous Docking

To extend underwater duration is an important issue for autonomous underwater vehicles. Limited duration restricts the working ability of an unmanned marine vehicle (UMV) and needs frequent surface support. One of the solutions to this problem is docking that can implement functions as recharging, data exchange, maintaining and so on. A novel docking method based on manipulator assistance is carried out. In this method, a fixed handle near docking port is caught by the manipulator on the vehicle firstly. The manipulator can be controlled to obtain the vehicles body a suitable position and orientation for autonomous docking. The manipulator with floating based can be looked on as one serial manipulator with a fixed anchor. The kinematics analysis is given by using the MATLAB and ADAMS. The simulation results suggest that docking method has more stability and accuracy, and it can also reduce the collision between docking port and the vehicle. The method provides a conception of docking process between all kinds of unman marine vehicles and docking ports.

Perturbation observer-based adaptive passive control for nonlinear systems with uncertainties and disturbances

2016 ◽  
Vol 40 (4) ◽  
pp. 1223-1236 ◽  
Author(s):  
B Yang ◽  
L Jiang ◽  
CK Zhang ◽  
YY Sang ◽  
T Yu ◽  
...  
Keyword(s):  
Nonlinear Systems ◽  
Passive Control ◽  
Estimation Error ◽  
High Gain ◽  
Parametric Estimation ◽  
System Stability ◽  
Nonlinearity Parameter ◽  
Fast Time ◽  
Control Effort ◽  
Control Scheme

In this paper, a perturbation observer-based adaptive passive control scheme is developed to provide great robustness of nonlinear systems against the unpredictable uncertainties and disturbances therein. The proposed scheme includes a high-gain perturbation observer and a robust passive controller. The high-gain perturbation observer is designed to estimate online the perturbation aggregated from the combinatorial effect of system nonlinearity, parameter uncertainty, unmodelled dynamics and fast time-varying external disturbances. Then the robust passive controller, using the estimated perturbation, can produce the minimal control effort needed to compensate for the magnitude of the actual current perturbation. Furthermore, the convergence of estimation error of the high-gain perturbation observer and the closed-loop system stability are analyzed theoretically. Finally, two practical examples are given to show the effectiveness and advantages of the proposed approach over the accurate model-based passive control scheme and the linearly parametric estimation-based adaptive passive control scheme.

Wheeled Mobile Robot Tracking Control without Velocity Measurement

2013 ◽  
Vol 373-375 ◽  
pp. 231-237 ◽  
Author(s):  
Qiang Wang ◽  
Guang Tong ◽  
Xin Xing
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
Velocity Measurement ◽  
Tracking Control ◽  
Wheeled Mobile Robot ◽  
Design Parameters ◽  
Wheeled Mobile Robots ◽  
Trajectory Tracking Control ◽  
Robot Tracking ◽  
Control Scheme

In this paper, a new robust trajectory tracking control scheme for wheeled mobile robots without velocity measurement is proposed. In the proposed controller, the velocity observer is used to estimate the velocity of wheeled mobile robot. The dynamics of wheeled mobile robot is considered to develop the controller. The proposed controller has the following features: i) The proposed controller has good robustness performance; ii) It is easy to improve tracking performance by setting only one design parameters.

scholarly journals An Advanced Guidance and Control System for an Unmanned Vessel with Azimuthal Thrusters

2018 ◽  
Author(s):  
M Bibuli ◽  
Ga Bruzzone ◽  
Gi Bruzzone ◽  
M Caccia ◽  
G Camporeale ◽  
...  
Keyword(s):  
Autonomous Navigation ◽  
Control Strategies ◽  
Vertical Axis ◽  
Control Loop ◽  
Guidance And Control ◽  
Marine Vehicles ◽  
Regulation Scheme ◽  
Control Scheme ◽  
Constrained Environments ◽  
And Control

The proposed paper presents the design and development of the combined guidance and control strategies for the autonomous navigation of an unmanned vessel characterized by azimuth-based thrust architecture. Autonomous Marine Vehicles (AMVs) are consolidates technological tools commonly employed for different tasks such as exploration, sampling and intervention. With the final aim of autonomous shipping, the capabilities of AMVs have to be migrated and adapted towards the reliable and safe control of commercial-like unmanned vessel, that are taking place thanks to a number of technological research projects. The employment of new concept hulls and thrust configurations, as for instance Small Waterplane Area Twin Hull (SWATH) combined with Azimuthal propulsion (common propeller-based thruster with the capability of 360◦ rotation around the vertical axis), requires robust guidance techniques to provide precise and reliable motion control during navigation. The paper proposes a dual-loop guidance and control scheme able to provide advanced navigation capabilities. In particular, the inner control loop, devoted to the actuation of the azimuthal thrusters, allows the tracking of reference course angle (namely the autopilot). Such a control loop is characterized by a modified PID regulation scheme, where a novel adaptive derivative component is inserted in order to improve the convergence curve towards the required course reference. The outer guidance loop, based on Lyapunov/virtual-target approach, allows the vessel to track generic desired paths, thus enhancing the autonomous navigation capabilities also in constrained environments. The paper will provide a deep design and analysis approach for the developed techniques, as well as simulation results of the combined guidance and control scheme, proving the reliability of the proposed approach in different operative conditions. Experimental results will be provided, depending on the availability of the actual autonomous vessel (currently under final development/test phases and related to the specific project activities). 

General Screening of Surface Alloys for Catalysis

2020 ◽  
Author(s):  
Matthew Montemore ◽  
Chukwudi F. Nwaokorie ◽  
Gbolade O. Kayode
Keyword(s):  
Electronic Structure ◽  
Catalytic Performance ◽  
Structural Features ◽  
Design Parameters ◽  
Surface Alloys ◽  
Catalytic Surfaces ◽  
Challenges And Opportunities ◽  
Adsorption Energies ◽  
Using Data ◽  
Structure Properties

Intensive research in catalysis has resulted in design parameters for many important catalytic reactions; however, designing new catalysts remains difficult, partly due to the time and expense needed to screen a large number of potential catalytic surfaces. Here, we create a general, efficient model that can be used to screen surface alloys for many reactions without any quantum-based calculations. This model allows the prediction of the adsorption energies of a variety of species (explicitly shown for C, N, O, OH, H, S, K, F) on metal alloy surfaces that include combinations of nearly all of the d-block metals. We find that a few simple structural features, chosen using data-driven techniques and physical understanding, can be used to predict electronic structure properties. These electronic structure properties are then used to predict adsorption energies, which are in turn used to predict catalytic performance. This framework is interpretable and gives insight into how underlying structural features affect adsorption and catalytic performance. We apply the model to screen more than 10<sup>7</sup> unique surface sites on approximately 10<sup>6</sup> unique surfaces for 7 important reactions. We identify novel surfaces with high predicted catalytic performance, and demonstrate challenges and opportunities in catalyst development using surface alloys. This work shows the utility of a general, reusable model that can be applied in new contexts without requiring new data to be generated.<br>

Study on Regional Traffic Control Optimization Based on State Analysis

2010 ◽  
Vol 44-47 ◽  
pp. 3959-3964
Author(s):  
Liang Zhi Zhang ◽  
Lei Jia ◽  
Mi Nai He
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Traffic Control ◽  
User Equilibrium ◽  
Solution Procedure ◽  
Design Parameters ◽  
Signal Control ◽  
Control Optimization ◽  
Proposed Model ◽  
Control Scheme

The aim of regional traffic control optimization is to find the optimal design parameters while thinking over the route choice of users. This problem can be formulated as a bi-level programming program. In the program, signal control scheme and user equilibrium traffic assignment are optimized in the upper and lower level respectively. The solution procedure developed with the genetic algorithm has been tested with an example of factual road network.Numerical experiment verified the proposed model is quite promising for use in design of regional signal control.

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