Line-of-sight guidance law for path following of amphibious hovercrafts with big and time-varying sideslip compensation

2019 ◽  
Vol 172 ◽  
pp. 531-540 ◽  
Author(s):  
Yuanhui Wang ◽  
Haiyan Tong ◽  
Mingyu Fu
Keyword(s):  
Path Following ◽  
Line Of Sight ◽  
Time Varying ◽  
Guidance Law

scholarly journals Fuzzy-Based Optimal Adaptive Line-of-Sight Path Following for Underactuated Unmanned Surface Vehicle with Uncertainties and Time-Varying Disturbances

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Dongdong Mu ◽  
Guofeng Wang ◽  
Yunsheng Fan ◽  
Yiming Bai ◽  
Yongsheng Zhao
Keyword(s):  
Neural Network ◽  
Path Following ◽  
Line Of Sight ◽  
Time Varying ◽  
Parameter Learning ◽  
Learning Method ◽  
External Disturbances ◽  
Unmanned Surface Vehicle ◽  
Loop Control ◽  
Nussbaum Function

This paper investigates the path following control problem for an underactuated unmanned surface vehicle (USV) in the presence of dynamical uncertainties and time-varying external disturbances. Based on fuzzy optimization algorithm, an improved adaptive line-of-sight (ALOS) guidance law is proposed, which is suitable for straight-line and curve paths. On the basis of guidance information provided by LOS, a three-degree-of-freedom (DOF) dynamic model of an underactuated USV has been used to design a practical path following controller. The controller is designed by combining backstepping method, neural shunting model, neural network minimum parameter learning method, and Nussbaum function. Neural shunting model is used to solve the problem of “explosion of complexity,” which is an inherent illness of backstepping algorithm. Meanwhile, a simpler neural network minimum parameter learning method than multilayer neural network is employed to identify the uncertainties and time-varying external disturbances. In particular, Nussbaum function is introduced into the controller design to solve the problem of unknown control gain coefficient. And much effort is made to obtain the stability for the closed-loop control system, using the Lyapunov stability theory. Simulation experiments demonstrate the effectiveness and reliability of the improved LOS guidance algorithm and the path following controller.

scholarly journals 3DOF Adaptive Line-Of-Sight Based Proportional Guidance Law for Path Following of AUV in the Presence of Ocean Currents

2019 ◽  
Vol 9 (17) ◽  
pp. 3518 ◽  
Author(s):  
Fengxu Liu ◽  
Yue Shen ◽  
Bo He ◽  
Junhe Wan ◽  
Dianrui Wang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Path Following ◽  
Lyapunov Theory ◽  
Line Of Sight ◽  
Average Error ◽  
Drift Angle ◽  
Reference Path ◽  
Guidance Law ◽  
Look Ahead ◽  
Three Degrees Of Freedom

In order to achieve high-precision path following of autonomous underwater vehicle (AUV) in the horizontal plane, a three degrees-of-freedom adaptive line-of-sight based proportional (3DOFAPLOS) guidance law is proposed. Firstly, the path point coordinate system is introduced, which is suitable for the conversion of an arbitrary path. Then, the appropriate look-ahead distance is obtained by an improved adaptive line-of-sight (ALOS) according to three degrees-of-freedom (3DOF), including the cross-track error, the curvature of reference path, and the forward speed. Moreover, combining three degrees-of-freedom ALOS (3DOFALOS) with proportional guidance law, the desired heading is calculated considering the drift angle. 3DOFAPLOS has two functions: in the convergence stage, 3DOFALOS plays a leading role, making AUV converge to the path more quickly and smoothly. In the guidance stage, proportional guidance law plays a major role in effectively resisting the influence of drift angle and making AUV sail along the reference path. If the path is curved, 3DOFALOS makes contributions in both stages, adjusting look-ahead distance in real time with respect to curvature. The stability of the designed closed system is proved by Lyapunov theory. Both simulation and experiment results have verified that 3DOFAPLOS has a satisfactory result, which improves tracking performance more than 50% compared with the traditional line-of-sight (LOS). Specifically, the mean average error (MAE) of path following under 3DOFAPLOS can be reduced by about 60%, and the root mean square error (RMSE) can be reduced by about 50% compared with LOS.

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 Path Following Control for Underactuated Airships with Magnitude and Rate Saturation

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7176
Author(s):  
Huabei Gou ◽  
Xiao Guo ◽  
Wenjie Lou ◽  
Jiajun Ou ◽  
Jiace Yuan
Keyword(s):  
Path Following ◽  
Line Of Sight ◽  
Trial And Error ◽  
Guidance Law ◽  
Path Following Control ◽  
Control Scheme ◽  
Markov Decision ◽  
Optimal Action ◽  
Action Policy ◽  
Policy Optimization

This paper proposes a reinforcement learning (RL) based path following strategy for underactuated airships with magnitude and rate saturation. The Markov decision process (MDP) model for the control problem is established. Then an error bounded line-of-sight (LOS) guidance law is investigated to restrain the state space. Subsequently, a proximal policy optimization (PPO) algorithm is employed to approximate the optimal action policy through trial and error. Since the optimal action policy is generated from the action space, the magnitude and rate saturation can be avoided. The simulation results, involving circular, general, broken-line, and anti-wind path following tasks, demonstrate that the proposed control scheme can transfer to new tasks without adaptation, and possesses satisfying real-time performance and robustness.

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.

Fully distributed guidance laws for unmanned aerial vehicles formation flight

2019 ◽  
Vol 42 (5) ◽  
pp. 965-980 ◽  
Author(s):  
Xiaoqian Wei ◽  
Jianying Yang ◽  
Xiangru Fan
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Group Formation ◽  
Formation Flight ◽  
Line Of Sight ◽  
Time Varying ◽  
Flight Trajectory ◽  
Adaptive Technology ◽  
Guidance Law ◽  
Aerial Vehicles ◽  
Guidance Laws

In this paper, three fully distributed guidance laws are designed for unmanned aerial vehicles formation flight, which have the following advantages. Adaptive technology in novel guidance laws can adapt to various graphs that only need one spanning tree. Cooperative formation does not need to set the virtual structure of formation in advance, but only needs to adjust the formation parameters in the guidance law to achieve the desired time-varying formation. This paper uses a guidance law perpendicular to the line of sight to make the flight trajectory more straight; hence, enhancing its applicability in real-world scenarios. These new guidance laws also enable group formation transformation and can optimize the unmanned aerial vehicles’ formation without global information to obtain the optimum performance of the formation. The simulation results show the practicability and effectiveness of the new method.

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