scholarly journals SMCSPO-Based Robust Control of AUV in Underwater Environments including Disturbances

2021 ◽  
Vol 11 (22) ◽  
pp. 10978
Author(s):  
Hyun-Hee Kim ◽  
Min-Cheol Lee ◽  
Hyeon-Jin Cho ◽  
Jun-Ho Hwang ◽  
Jong-Seob Won

In the underwater environment, robust control algorithms are required to control autonomous underwater vehicles (AUVs) at high speed while preventing large nonlinearities and disturbances. Sliding mode control (SMC) is a well-known robust control theory and has been widely used not only in AUV control but also in systems such as industrial robots which have high nonlinearity in their system dynamics. However, SMC has the disadvantage of causing chattering on the control input, and it is difficult to apply this method to the control fins of an AUV system that cannot move its fins at high speed underwater. In this work, a design for a sliding mode control with sliding perturbation observer (SMCSPO) algorithm is applied to AUVs, and the simulation results under underwater disturbance conditions are discussed. From simulation using MATLAB, it is confirmed that AUV control using SMCSPO shows better trajectory tracking control performance without chattering than PID control.

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142091627
Author(s):  
Jiajia Zhou ◽  
Xinyi Zhao ◽  
Zhiguang Feng ◽  
Di Wu

Trajectory tracking control of autonomous underwater vehicles in three-dimension always suffers disturbances such as input time delays and model uncertainties. Regarding this problem, an integral time-delay sliding mode control law is proposed in this article with dividing the vehicle’s input time delays model into cascade system consisting of a kinematics subsystem and a dynamics subsystem. Based on the established pose error equation and velocity error equation, a suitable Lyapunov–Krasovskii functional is given to analyze and guarantee the global stability of the whole system under reasonable assumptions. At last, comparative simulations are presented to demonstrate the effectiveness of the proposed method.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shuo Wang ◽  
Ju Jiang ◽  
Chaojun Yu

In this paper, a controller combining backstepping and adaptive supertwisting sliding mode control method is proposed for altitude and velocity tracking control of air-breathing hypersonic vehicles (AHVs). Firstly, the nonlinear longitudinal model of AHV is introduced and transformed into a strict feedback form, to which the backstepping method can be applied. Considering the longitudinal trajectory tracking control problem (altitude control and velocity control), the altitude tracking control system is decomposed to several one-order subsystems based on the backstepping method, and an adaptive supertwisting sliding mode controller is designed for each subsystem, in order to obtain the virtual control variables and actual control input. Secondly, the overall stability of the closed-loop system is proved by the Lyapunov stability theory. At last, the simulation is carried out on an AHV model. The results show that the proposed controller has good control performances and good robustness in the parameter perturbation case.


2019 ◽  
Vol 52 (7-8) ◽  
pp. 1072-1083 ◽  
Author(s):  
Ting-Rui Liu

Divergent instability control of 2D pretwisted blade section of wind turbine driven by aerodynamic forces under disturbance is investigated. Realization of divergent instability control is based on two types of discrete sliding mode control algorithms. The structure is modeled as 2D pretwisted blade section integrated with structural damping, which is driven by aerodynamic model with perturbed disturbance. Discrete sliding mode control algorithm suitable for disturbance control is investigated to control divergent flap/lead-lag vibrations of blade section. To increase convergence performance and reduce the chattering phenomenon, discrete sliding mode control based on disturbance observer is applied. Convergence of disturbance observer is analyzed, and stability of closed-loop system is discussed. The simulation results show that not only the convergence accuracy can be improved by sliding mode control based on disturbance observer controller, but also the displacement chattering and the control input chattering can be effectively eliminated. Compared with conventional discrete sliding mode control, it has more advantages in the control of divergent instability. To facilitate the real-time realization and automation and at the same time to ensure accuracy, a design of quadratic feedback to build the performance control matrix in sliding mode control based on disturbance observer is developed in present study.


2018 ◽  
Vol 8 (1) ◽  
pp. 142-153
Author(s):  
Vu Trieu Minh ◽  
Mart Tamre ◽  
Even Sekhri

AbstractThis paper proposes the mathematical modeling and robust control algorithms for linear belt system with the help of sliding mode control approach. Due to the elasticity of the belt, the presence of frictions, and the un-modeled dynamics, conventional controllers cannot provide precise position control of carriage. Dealing with this kind of system, a robust controller is needed and the chattering-free sliding mode control (SMC) approach is used to design the robust controller. A belt stretching estimator is also incorporated into the control law. Simulations show that the system is free from chattering and robust to disturbances. The reference tracking position is performed with the minimal errors to an extent that can be considered negligible. The time for reaching the reference tracking position is very fast. The system is safe for all mechanical and electrical devices.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Guanxue Wang ◽  
Guohua Xu ◽  
Gang Liu ◽  
Wenjin Wang ◽  
Ben Li

The aim of this paper is to develop a fuzzy iterative sliding mode control (FISMC) scheme for special autonomous underwater vehicles (AUVs) on three-dimensional (3D) path following. In this paper, the characteristics of the AUV are considered, which include a large scale, large inertia, and high speed. The FISMC controller designs iterative sliding mode surfaces by using a hyperbolic tangent function to keep the system with fast convergence and robust performance. At the same time, system uncertainties and environmental disturbances are taken into account. The control algorithm introduces fuzzy control to optimize the control parameters online to enhance the adaptability of the system and inhibit the chattering of the actuators. The performance of the proposed FISMC is demonstrated with numerical simulations.


2021 ◽  
Vol 54 (3-4) ◽  
pp. 360-373
Author(s):  
Hong Wang ◽  
Mingqin Zhang ◽  
Ruijun Zhang ◽  
Lixin Liu

In order to effectively suppress horizontal vibration of the ultra-high-speed elevator car system. Firstly, considering the nonlinearity of guide shoe, parameter uncertainties, and uncertain external disturbances of the elevator car system, a more practical active control model for horizontal vibration of the 4-DOF ultra-high-speed elevator car system is constructed and the rationality of the established model is verified by real elevator experiment. Secondly, a predictive sliding mode controller based on adaptive fuzzy (PSMC-AF) is proposed to reduce the horizontal vibration of the car system, the predictive sliding mode control law is achieved by optimizing the predictive sliding mode performance index. Simultaneously, in order to decrease the influence of uncertainty of the car system, a fuzzy logic system (FLS) is designed to approximate the compound uncertain disturbance term (CUDT) on-line. Furthermore, the continuous smooth hyperbolic tangent function (HTF) is introduced into the sliding mode switching term to compensate the fuzzy approximation error. The adaptive laws are designed to estimate the error gain and slope parameter, so as to increase the robustness of the system. Finally, numerical simulations are conducted on some representative guide rail excitations and the results are compared to the existing solution and passive system. The analysis has confirmed the effectiveness and robustness of the proposed control method.


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