scholarly journals Composite Curve Path following an Underactuated AUV

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Ben Li ◽  
Guohua Xu ◽  
Yingkai Xia ◽  
Wenjin Wang ◽  
Zhen Su
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Sliding Mode ◽  
Path Following ◽  
Curve Path ◽  
Switching Algorithm ◽  
Guidance Law ◽  
Exponentially Stable ◽  
Cascade Structure ◽  
Virtual Point ◽  
Composite Curve

This paper addresses the problem of composite curve path following for an underactuated autonomous underwater vehicle by utilizing an adaptive integral line-of-sight (AILOS) guidance and nonlinear iterative sliding mode (NISM) controller. First, the composite curve path is parametrized by a common scalar variable in a continuous way. Then, the kinematics error of an underactuated vehicle is described based on the nonprojection Frenet–Serret frame with a virtual point, which can be eliminated by the virtual point control and AILOS guidance. Meanwhile, the subpath switching algorithm is studied to realize the global path following for the composite curve path. Besides, the NISM controller is cascaded with the AILOS guidance law, and the cascade structure proved to be globally κ -exponentially stable under the influence of slow time-varying currents. Finally, simulations are considered to demonstrate the effectiveness of the proposed composite curve path following control scheme.

Time-Varying Vector Field Guidance Law for Path Following and Obstacle Avoidance for Underactuated Autonomous Vehicles

2019 ◽  
Author(s):  
Haitong Xu ◽  
M. A. Hinostroza ◽  
C. Guedes Soares
Keyword(s):  
Vector Field ◽  
Obstacle Avoidance ◽  
Autonomous Vehicles ◽  
Sliding Mode ◽  
Path Following ◽  
Guidance System ◽  
Time Varying ◽  
Guidance Law ◽  
Heading Angle ◽  
Vector Field Guidance

Abstract This paper presents a time-varying vector field guidance law for path-following control of underactuated autonomous vehicles. The proposed guidance law employs a time-varying equation to calculate the desired heading angle. A sliding mode controller is designed to track the desired heading angle, and it is proved to be globally exponentially stable (GES). With this controller, the stability proof for guidance system is presented and the equilibrium point of the guidance system is Uniform Global Asymptotic Stable (UGAS). In order to avoid the obstacle when ship approaching the predefined path, a combined Path-following and repelling field based obstacle avoidance system is proposed in this paper. Simulations are carried out to validate the performance of the combined path-following and collision avoidance system.

scholarly journals Extended state observer-based integral line-of-sight guidance law for path following of underactuated unmanned surface vehicles with uncertainties and ocean currents

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110110
Author(s):  
Mingcong Li ◽  
Chen Guo ◽  
Haomiao Yu
Keyword(s):  
Sliding Mode ◽  
Path Following ◽  
State Observer ◽  
Extended State Observer ◽  
Ocean Currents ◽  
Line Of Sight ◽  
Extended State ◽  
Integral Sliding Mode ◽  
Unmanned Surface Vehicles ◽  
Guidance Law

This article focuses on the problem of path following for underactuated unmanned surface vehicles (USVs) considering model uncertainties and time-varying ocean currents. An extended state observer (ESO)-based integral line-of-sight (ILOS) with an integral sliding mode adaptive fuzzy control scheme is proposed as the main control framework. First, a novel ESO is employed to estimate the surge and sway velocities based on the kinetic model, which are difficult to measure directly. Then, the adaptive ILOS guidance law is proposed, in which the integral vector is incorporated into the adaptive method to estimate the current velocities. Meanwhile, an improved fuzzy algorithm is introduced to optimize the look-ahead distance. Second, the controller is extended to deal with the USV yaw and surge velocity signal tracking using the integral sliding mode technique. The uncertainties of the USV are approximated via the adaptive fuzzy method, and an auxiliary dynamic system is presented to solve the problem of actuator saturation. Then, it is proved that all of the error signals in the closed-loop control system are uniformly ultimately bounded. Finally, a comparative simulation substantiates the availability and superiority of the proposed method for ESO-based ILOS path following of USV.

scholarly journals Control of Unmanned Surface Vehicle Along the Desired Trajectory Using Improved Line of Sight and Estimated Sideslip Angle

2021 ◽  
Vol 28 (2) ◽  
pp. 18-26
Author(s):  
Ligang Li ◽  
Zhiyuan Pei ◽  
Jiucai Jin ◽  
Yongshou Dai
Keyword(s):  
Path Following ◽  
State Observer ◽  
Extended State Observer ◽  
Line Of Sight ◽  
Extended State ◽  
Sideslip Angle ◽  
Unmanned Surface Vehicle ◽  
Curve Path ◽  
Guidance Law ◽  
Path Following Control

Abstract In order to improve the accuracy and robustness of path following control for an Unmanned Surface Vehicle (USV) suffering from unknown and complex disturbances, a variable speed curve path following a control method based on an extended state observer was proposed. Firstly, the effect of the environmental disturbances on the USV is equivalent to an unknown and time-varying sideslip angle, and the sideslip angle is estimated by using the extended state observer (ESO) and compensated in the Line of Sight (LOS) guidance law. Secondly, based on the traditional LOS guidance law, the design of the surge velocity guidance law is added to enable the USV to self-adjust the surge velocity according to the curvature of the curve path, thus further improving the tracking accuracy. Finally, the heading and speed controller of the USV is designed by using a sliding mode control to track the desired heading and speed accurately, and then the path following control of the USV’s curve path is realised. Simulation results verify the effectiveness of the proposed method.

scholarly journals Path Following Based on Waypoints and Real-Time Obstacle Avoidance Control of an Autonomous Underwater Vehicle

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 795 ◽  
Author(s):  
Xuliang Yao ◽  
Xiaowei Wang ◽  
Feng Wang ◽  
Le Zhang
Keyword(s):  
Real Time ◽  
Obstacle Avoidance ◽  
Autonomous Underwater Vehicle ◽  
Control Method ◽  
Path Following ◽  
Underwater Vehicle ◽  
System Stability ◽  
Guidance Law ◽  
Angular Velocities ◽  
Avoidance Control

This paper studies three-dimensional (3D) straight line path following and obstacle avoidance control for an underactuated autonomous underwater vehicle (AUV) without lateral and vertical driving forces. Firstly, the expected angular velocities are designed by using two different methods in the kinematic controller. The first one is a traditional method based on Line-of-sight (LOS) guidance law, and the second one is an improved method based on model predictive control (MPC). At the same time, a penalty item is designed by using the obstacle information detected by onboard sensors, which can realize the real-time obstacle avoidance of the unknown obstacle. Then, in order to overcome the uncertainty of the dynamics model and the saturation of actual control input, the dynamic controller is designed by using sliding mode control (SMC) technology. Finally, in the simulation experiment, the performance of the improved control method is verified by comparison with two traditional control methods based on LOS guidance law. Since the constraint of an AUV’s angular velocities are considered in MPC, simulation results show that the improved control method uses MPC, and SMC not only improves the tracking quality of the AUV when switching paths near the waypoints and realizes real-time obstacle avoidance but also effectively reduces the mean square error (MSE) and saturation rate of the rudder angle. Therefore, this control method is more conducive to the system stability and saves energy.

scholarly journals Fuzzy Iterative Sliding Mode Control Applied for Path Following of an Autonomous Underwater Vehicle with Large Inertia

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Guanxue Wang ◽  
Guohua Xu ◽  
Gang Liu ◽  
Wenjin Wang ◽  
Ben Li
Keyword(s):  
Sliding Mode Control ◽  
High Speed ◽  
Large Scale ◽  
Autonomous Underwater Vehicle ◽  
Sliding Mode ◽  
Autonomous Underwater Vehicles ◽  
Three Dimensional ◽  
Path Following ◽  
Mode Control ◽  
Tangent Function

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.

scholarly journals High-precision prescribed-time path following for quadrotor

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142092005
Author(s):  
Yibo Ding ◽  
Xiaogang Wang ◽  
Yuliang Bai ◽  
Naigang Cui
Keyword(s):  
Unmanned Aerial Vehicle ◽  
High Precision ◽  
Control Structure ◽  
Sliding Mode ◽  
Path Following ◽  
Guidance Law ◽  
Aerial Vehicle ◽  
The Stability ◽  
Flight Scheme ◽  
Compensation Function

A high-precision prescribed-time guidance law is developed for a quadrotor to accomplish precise path following at predesigned time T. Firstly, a new control structure is proposed for a quadrotor to perform fixed-velocity back-to-turn flying mode by introducing four controllers, which can realize a non-sideslip and bank-to-turn flight scheme just like a fixed-wing unmanned aerial vehicle. Then, prescribed-time guidance law is presented based on fixed-velocity back-to-turn flying mode via combining sliding mode control with a compensation function [Formula: see text] to improve tracking precision of conventional methods. Compensation function [Formula: see text] is designed to make state error achieve convergence at prescribed time exactly. Meanwhile, global sliding mode is established to enhance robustness of the system. Then, the stability and characteristic of prescribed-time convergence are proved strictly. Finally, simulations with a 6-degree-of-freedom quadrotor model are carried out to demonstrate the effectiveness and superiority of prescribed-time guidance law by comparing with traditional guidance law.

Experimental validation of constraint mitigation algorithm in underwater robot depth control

2018 ◽  
Vol 233 (3) ◽  
pp. 264-275
Author(s):  
Juan Luis Rosendo ◽  
Benoit Clement ◽  
Fabricio Garelli
Keyword(s):  
Closed Loop ◽  
Autonomous Underwater Vehicle ◽  
Sliding Mode ◽  
Path Following ◽  
Underwater Robot ◽  
Modeling And Control ◽  
Depth Control ◽  
Actuator Constraints ◽  
Proportional Derivative Controller ◽  
And Control

This work explores both modeling and control of the experimental Ciscrea autonomous underwater vehicle. A 6-degree-of-freedom model is presented and validated for turn and emerge/sink maneuvers. Then, a constraint compensating algorithm is proposed based on quasi-sliding mode conditioning ideas and added to a pre-existing inaccessible proportional-derivative controller in order to improve the overall closed-loop response. By considering actuator constraints, the employed technique allows path following at greater speed than the original controller for a given error tolerance. Experimental results on the so-called Ciscrea underwater robot are presented.

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