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.

3D Nonlinear Guidance Law for Bank-to-Turn Missile

2011 ◽  
Vol 317-319 ◽  
pp. 727-733
Author(s):  
Shuang Chun Peng ◽  
Liang Pan ◽  
Tian Jiang Hu ◽  
Lin Cheng Shen
Keyword(s):  
Three Dimensional ◽  
Lyapunov Theory ◽  
Line Of Sight ◽  
Rate Model ◽  
Guidance Law ◽  
Terminal Constraints ◽  
Guidance Laws ◽  
3D Guidance ◽  
Guidance Model ◽  
Vector Description

A new three-dimensional (3D) nonlinear guidance law is proposed and developed for bank-to-turn (BTT) with motion coupling. First of all, the 3D guidance model is established. In detail, the line-of-sight (LOS) rate model is established with the vector description method, and the kinematics model is divided into three terms of pitching, swerving and coupling, then by using the twist-based method, the LOS direction changing model is built for designing the guidance law with terminal angular constraints. Secondly, the 3D guidance laws are designed with Lyapunov theory, corresponding to no terminal constraints and terminal constraints, respectively. And finally, the simulation results show that the proposed guidance law can effectively satisfy the guidance precision requirements of BTT missile.

scholarly journals Optimal Path-Following Guidance with Generalized Weighting Functions Based on Indirect Gauss Pseudospectral Method

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Qi Chen ◽  
Xugang Wang ◽  
Jing Yang
Keyword(s):  
Degrees Of Freedom ◽  
Optimal Path ◽  
Pseudospectral Method ◽  
Path Following ◽  
Control Cost ◽  
Weighting Functions ◽  
Guidance Law ◽  
Computational Performance ◽  
Gauss Pseudospectral Method ◽  
Virtual Target

An indirect Gauss pseudospectral method based path-following guidance law is presented in this paper. A virtual target moving along the desired path with explicitly specified speed is introduced to formulate the guidance problem. By establishing a virtual target-fixed coordinate system, the path-following guidance is transformed into a terminal guidance with impact angle constraints, which is then solved by using indirect Gauss pseudospectral method. Meanwhile, the acceleration dynamics are modeled as the first-order lag to the command. Using the receding horizon technique a closed-loop guidance law, which considers generalized weighting functions (even discontinuous) of both the states and the control cost, is derived. The accuracy and effectiveness of the proposed guidance law are validated by numerical comparisons. A STM32 Nucleo board based on the ARM Cortex-M7 processor is used to evaluate the real-time computational performance of the proposed indirect Gauss pseudospectral method. Simulations for various types of desired paths are presented to show that the proposed guidance law has better performance when compared with the existing results for pure pursuit, a nonlinear guidance law, and trajectory shaping path-following guidance and provides more degrees of freedom in path-following guidance design applications.

scholarly journals Modeling and Experimental Testing of an Unmanned Surface Vehicle with Rudderless Double Thrusters

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2051 ◽  
Author(s):  
Chunyue Li ◽  
Jiajia Jiang ◽  
Fajie Duan ◽  
Wei Liu ◽  
Xianquan Wang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Testing ◽  
Path Following ◽  
Model Parameters ◽  
Crucial Issue ◽  
Unknown Parameters ◽  
Path Following Control ◽  
Differential Thrust ◽  
Three Degrees Of Freedom ◽  
Propeller Thrust

Motion control of unmanned surface vehicles (USVs) is a crucial issue in sailing performance and navigation costs. The actuators of USVs currently available are mostly a combination of thrusters and rudders. The modeling for USVs with rudderless double thrusters is rarely studied. In this paper, the three degrees of freedom (DOFs) dynamic model and propeller thrust model of this kind of USV were derived and combined. The unknown parameters of the propeller thrust model were reduced from six to two. In the three-DOF model, the propulsion of the USV was completely provided by the resultant force generated by double thrusters and the rotational moment was related to the differential thrust. It combined the propeller thrust model to represent the thrust in more detail. We performed a series of tests for a 1.5 m long, 50 kg USV, in order to obtain the model parameters through system identification. Then, the accuracy of the modeling and identification results was verified by experimental testing. Finally, based on the established model and the proportional derivative+line of sight (PD+LOS) control algorithm, the path-following control of the USV was achieved through simulations and experiments. All these demonstrated the validity and practical value of the established model.

Improved Integral LOS Guidance and Path-Following Control for an Unmanned Robot Sailboat via the Robust Neural Damping Technique

2019 ◽  
Vol 72 (06) ◽  
pp. 1378-1398 ◽  
Author(s):  
Guoqing Zhang ◽  
Jiqiang Li ◽  
Bo Li ◽  
Xianku Zhang
Keyword(s):  
External Disturbance ◽  
Path Following ◽  
Basic Function ◽  
Lyapunov Theory ◽  
Neural Controller ◽  
Adaptive Parameter ◽  
Guidance Law ◽  
Path Following Control ◽  
Adaptive Neural Controller ◽  
Robust Adaptive

This paper introduces a scheme for waypoint-based path-following control for an Unmanned Robot Sailboat (URS) in the presence of actuator gain uncertainty and unknown environment disturbances. The proposed scheme has two components: intelligent guidance and an adaptive neural controller. Considering upwind and downwind navigation, an improved version of the integral Line-Of-Sight (LOS) guidance principle is developed to generate the appropriate heading reference for a URS. Associated with the integral LOS guidance law, a robust adaptive algorithm is proposed for a URS using Radial Basic Function Neural Networks (RBF-NNs) and a robust neural damping technique. In order to achieve a robust neural damping technique, one single adaptive parameter must be updated online to stabilise the effect of the gain uncertainty and the external disturbance. To ensure Semi-Global Uniform Ultimate Bounded (SGUUB) stability, the Lyapunov theory has been employed. Two simulated experiments have been conducted to illustrate that the control effects can achieve a satisfactory performance.

Drift angle compensation-based adaptive line-of-sight path following for autonomous underwater vehicle

2019 ◽  
Vol 93 ◽  
pp. 101943 ◽  
Author(s):  
Fengxu Liu ◽  
Yue Shen ◽  
Bo He ◽  
Dianrui Wang ◽  
Junhe Wan ◽  
...  
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Path Following ◽  
Underwater Vehicle ◽  
Line Of Sight ◽  
Drift Angle

scholarly journals Design and Verification of Heading and Velocity Coupled Nonlinear Controller for Unmanned Surface Vehicle

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3427 ◽  
Author(s):  
Jiucai Jin ◽  
Jie Zhang ◽  
Deqing Liu
Keyword(s):  
Degrees Of Freedom ◽  
Lyapunov Theory ◽  
Velocity Control ◽  
Nonlinear Controller ◽  
Experiment Data ◽  
Unmanned Surface Vehicle ◽  
Autonomous Operation ◽  
The Stability ◽  
Velocity Tracking ◽  
Three Degrees Of Freedom

Unmanned Surface Vehicle (USV) is a novel multifunctional platform for ocean observation, and its heading and velocity control are essential and important for autonomous operation. A coupled heading and velocity controller is designed using backstepping technology for an USV called ‘USBV’ (Unmanned Surface Bathymetry Vehicle). The USBV is an underactuated catamaran, where the heading and velocity are controlled together by two thrusters at the stern. The three degrees-of-freedom equations are used for USBV’s modeling, which is identified using experiment data. The identified model, with two inputs, induces heading and velocity tracking, which are coupled. Based on the model, a nonlinear controller for heading and velocity are acquired using backstepping technology. The stability of the controller is proved by Lyapunov theory under some assumptions. The verification is presented by lake and sea experiments.

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