scholarly journals Investigation of robust ship course control based on auxiliary loop method

2021 ◽  
pp. 248-252
Author(s):  
Aliya Imangazieva
Keyword(s):  
Control Law ◽  
Sea Waves ◽  
Unknown Parameters ◽  
External Disturbances ◽  
Loop Method ◽  
Wind Gusts ◽  
Course Control ◽  
External Conditions ◽  
Yaw Angle ◽  
The Mathematical Model

A novel robust control law is investigated on the problem of ship stabilization on the trajectory, which allows one to compensate perturbations in the parameters of the mathematical model of ship dynamics in cases of their changes caused by external conditions, namely: sea waves, currents, wind gusts, etc. To implement the proposed control law, only measured adjustable values are required such as the yaw angle and the control action that is the angle of the rudder of the ship. The synthesized ship course control system was investigated in MATLAB. The law of controlling the ship’s course with unknown parameters and external disturbances in the power supply is proposed. The design of the control law is based on a robust auxiliary loop algorithm and Khalil observers. The simulations illustrate the efficiency of the proposed control law.

Simulation Research of the Ship Course Control System

2012 ◽  
Vol 490-495 ◽  
pp. 871-875
Author(s):  
Hong Wei Gao
Keyword(s):  
Control System ◽  
Control Law ◽  
External Disturbances ◽  
Simulation Research ◽  
Internal Model Principle ◽  
Safe Navigation ◽  
System A ◽  
Course Control ◽  
Ship Control ◽  
Yaw Angle

In order to ensure the safe navigation, the ship course control problem is considered. By developing a sensitivity approach and the internal model principle to a ship control system, a course controller is designed. Simulation research shows that, by using the proposed control law, the ship can sail along the desired orientation with minimal energy when there are no current, wind and waves, while the controller can adjust the yaw angle caused by the external disturbances to the desired orientation fast.

The Course Control of Air Cushion Vehicle With Uncertainties and Input Saturation

2020 ◽  
Author(s):  
Yuanhui Wang ◽  
Xiyun Jiang ◽  
Mingyu Fu
Keyword(s):  
Dynamic System ◽  
Closed Loop ◽  
Wind Waves ◽  
Radial Basis Function Network ◽  
Input Saturation ◽  
Control Law ◽  
External Disturbances ◽  
Course Control ◽  
Air Cushion ◽  
Air Cushion Vehicle

Abstract In the presence of input saturation and unknown the internal uncertainties, external disturbances, including sea wind, waves and currents, this paper develops a course control law for the system of air cushion vehicle (ACV) using neural network and auxiliary dynamic system to improve the maneuverability and safety. In the design process of the course control law of air cushion vehicle, the two problems of input saturation and uncertainties are considered. On one hand, an effective auxiliary dynamic system is introduced to solve the input saturation problem and reduce its impact on the system. On the other hand, in order to deal with the internal and external disturbances of the system, the fully turned radial basis function network (FTRBFNN) is combined with the control law, and its adaptive ability makes the system compensate better for unknown uncertainties better than RBFNN. The stability of closed-loop system is proved by Lyapunov analysis. It is proved that the designed course control law can maintain ACV’s heading at desired value, while guaranteeing the uniform ultimate boundedness of all signals in the ACV closed-loop control system. Finally, simulations on ACV are carried out to demonstrate the effectiveness of the developed ACV course control law.

scholarly journals Control of distillation column under perturbations: a case study

2020 ◽  
pp. 182-186
Author(s):  
Pavel Gushchin ◽  
Igor Furtat ◽  
Artem Nekhoroshikh ◽  
Julia Chugina ◽  
Sergey Vrazhevsky ◽  
...  
Keyword(s):  
Distillation Column ◽  
Control Law ◽  
Unknown Parameters ◽  
External Disturbances

The control law of distillation column under unknown parameters and external disturbances in feed is obtained. The control law design is based on the robust suboptimal auxiliary loop algorithm for rejecting perturbations and ensuring the track of column output to reference signal.The simulations illustrate an efficiency of proposed scheme and comparison with some existing ones.

Uniformly ultimately bounded tracking control of sandwich systems with nonsymmetric sandwiched dead-zone nonlinearity and input saturation constraint

2021 ◽  
pp. 107754632098794
Author(s):  
Meysam Azhdari ◽  
Tahereh Binazadeh
Keyword(s):  
Dead Zone ◽  
Input Saturation ◽  
Closed Loop System ◽  
Unknown Parameters ◽  
External Disturbances ◽  
Uniformly Ultimately Bounded ◽  
Output Tracking ◽  
Saturation Constraint ◽  
Two Phases ◽  
Practical Constraints

This article studies the uniformly ultimately bounded output tracking problem of uncertain nonlinear sandwich systems with sandwiched dead-zone nonlinearity in the presence of some practical constraints such as nonsymmetric input saturation, model uncertainties, time-varying external disturbances, and unknown parameters. Due to the existence of both dead-zone and saturation nonlinearities, the design process is more complicated; therefore, to solve the design complexities, the designing process is divided into two phases. The proposed method leads to output tracking with acceptable accuracy. Moreover, all signals in the closed-loop system are ultimately bounded. Simulation results illustrate the applicability and effectiveness of the proposed method by its application on two practical sandwich systems (robotic system and electrohydraulic servo press system).

Study on the working state of the five hundred-meter aperture spherical telescope using step-wise assignment method

2014 ◽  
Vol 229 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Yu Liu ◽  
Feng Gao
Keyword(s):  
Nonlinear Equations ◽  
Analytical Solutions ◽  
Driving Mechanism ◽  
Initial Value ◽  
Unknown Parameters ◽  
Support Structure ◽  
Assignment Method ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model

The working state of the five hundred-meter aperture spherical telescope (FAST) is solved using the step-wise assignment method. In this paper, the mathematical model of the cable-net support structure of the FAST is set up by the catenary equation. There are a large number of nonlinear equations and unknown parameters of the model. The nonlinear equations are solved by using the step-wise assignment method. The method is using the analytical solutions of the cable-net equations of one working state as the initial value for the next working state, from which the analytical solutions of the nonlinear equations of the cable-net for each working state of the FAST and the tension and length of each driving cable can be obtained. The suggested algorithm is quite practically well suited to study the working state of the cable-net structures of the FAST. Also, the working state analysis result of the cable-net support structure of a reduced model of the cable-net structure reflector for the FAST is given to verify the reliability of the method. In order to show the validity of the method, comparisons with another algorithm to set the initial value are presented. This method has an important guiding significance to the further study on the control of the new type of flexible cable driving mechanism, especially the FAST.

scholarly journals A Coefficient Diagram Method Controller with Backstepping Methodology for Robotic Manipulators

2015 ◽  
Vol 66 (5) ◽  
pp. 270-276 ◽  
Author(s):  
Fouad Haouari ◽  
Bali Nourdine ◽  
Mohamed Segir Boucherit ◽  
Mohamed Tadjine
Keyword(s):  
Robotic Manipulators ◽  
Control Law ◽  
Control Procedure ◽  
Parametric Uncertainties ◽  
The Novel ◽  
External Disturbances ◽  
Diagram Method ◽  
Coefficient Diagram Method ◽  
Backstepping Controller ◽  
Puma Robot

AbstractA new robust control procedure for robot manipulators is proposed in this paper. Coefficients diagram method controllers CDM and Backstepping methodology are combined to create the novel control law. Two steps of backstepping on the resulting system are used to design a nonlinear CDM-Backstepping controller. Simulations on a PUMA robot including external disturbances, parametric uncertainties and noises are performed to show the effectiveness and feasibility of the proposed method.

scholarly journals Adaptive Synchronization for Uncertain Delayed Fractional-Order Hopfield Neural Networks via Fractional-Order Sliding Mode Control

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Meng ◽  
Xiaohong Wang
Keyword(s):  
Neural Networks ◽  
Fractional Order ◽  
Sliding Mode ◽  
Small Region ◽  
Hopfield Neural Networks ◽  
Adaptive Synchronization ◽  
Unknown Parameters ◽  
External Disturbances ◽  
Lyapunov Stability Criterion ◽  
Order Extension

Adaptive synchronization for a class of uncertain delayed fractional-order Hopfield neural networks (FOHNNs) with external disturbances is addressed in this paper. For the unknown parameters and external disturbances of the delayed FOHNNs, some adaptive estimations are designed. Firstly, a fractional-order switched sliding surface is proposed for the delayed FOHNNs. Then, according to the fractional-order extension of the Lyapunov stability criterion, a fractional-order sliding mode controller is constructed to guarantee that the synchronization error of the two uncertain delayed FOHNNs converges to an arbitrary small region of the origin. Finally, a numerical example of two-dimensional uncertain delayed FOHNNs is given to verify the effectiveness of the proposed method.

scholarly journals Decentralized 3D Collision Avoidance for Multiple UAVs in Outdoor Environments

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4101 ◽  
Author(s):  
Eduardo Ferrera ◽  
Alfonso Alcántara ◽  
Jesús Capitán ◽  
Angel Castaño ◽  
Pedro Marrón ◽  
...  
Keyword(s):  
Collision Avoidance ◽  
System Integration ◽  
Field Experiments ◽  
Positioning Systems ◽  
Wind Gusts ◽  
Aerial Vehicles ◽  
Multiple Uavs ◽  
Outdoor Environments ◽  
External Conditions ◽  
Field Experimentation

The use of multiple aerial vehicles for autonomous missions is turning into commonplace. In many of these applications, the Unmanned Aerial Vehicles (UAVs) have to cooperate and navigate in a shared airspace, becoming 3D collision avoidance a relevant issue. Outdoor scenarios impose additional challenges: (i) accurate positioning systems are costly; (ii) communication can be unreliable or delayed; and (iii) external conditions like wind gusts affect UAVs’ maneuverability. In this paper, we present 3D-SWAP, a decentralized algorithm for 3D collision avoidance with multiple UAVs. 3D-SWAP operates reactively without high computational requirements and allows UAVs to integrate measurements from their local sensors with positions of other teammates within communication range. We tested 3D-SWAP with our team of custom-designed UAVs. First, we used a Software-In-The-Loop simulator for system integration and evaluation. Second, we run field experiments with up to three UAVs in an outdoor scenario with uncontrolled conditions (i.e., noisy positioning systems, wind gusts, etc). We report our results and our procedures for this field experimentation.

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