Global Path-Following Control of Stochastic Underactuated Ships: A Level Curve Approach

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
K. D. Do
Keyword(s):  
Lyapunov Functions ◽  
Control Design ◽  
Path Following ◽  
Level Curve ◽  
Reference Path ◽  
Surface Ship ◽  
Path Following Control

A level curve approach is introduced to design global path-following controllers for an underactuated surface ship. The approach is based on the observation: if the position of the ship satisfies the equation of the reference path, then the ship will be on the path. Thus, the controllers are designed based on Lyapunov's direct and backstepping methods to force the position of the ship to satisfy the equation of the path and to move along the path tangentially. The approach does not require computation of the position from the ship to the path. Weak and strong nonlinear Lyapunov functions are introduced in the control design to overcome difficulties caused by underactuation and to guarantee boundedness of the sway velocity. Simulations are included to illustrate the effectiveness of the proposed results.

scholarly journals Modified Vector Field Path-Following Control System for an Underactuated Autonomous Surface Ship Modelin the Presence of Static Obstacles

2021 ◽  
Vol 9 (6) ◽  
pp. 652
Author(s):  
Haitong Xu ◽  
Miguel A. Hinostroza ◽  
C. Guedes Guedes Soares
Keyword(s):  
Control System ◽  
Vector Field ◽  
Path Following ◽  
Field Method ◽  
Integrated System ◽  
Ship Model ◽  
Surface Ship ◽  
Path Following Control ◽  
Exponentially Stable ◽  
Vector Field Method

A modified path-following control system using the vector field method for an underactuated autonomous surface ship model is proposed in the presence of static obstacles. With this integrated system, autonomous ships are capable of following the predefined path, while avoiding the obstacles automatically. It is different from the methods in most published papers, which usually study path-following and obstacle collision avoidance, separately. This paper considers the coupled path following and collision avoidance task as a whole. Meanwhile, the paper also shows the heading control design method in the presence of static obstacles. To obtain a strong stability property, a nonlinear autopilot is designed based on the manoeuvring tests of the free-running ship model. The equilibrium point of the controller is globally exponentially stable. For the guidance system, a novel vector field method was proposed, and the proof shows the coupled guidance and control system is uniform semi-global exponentially stable (USGES). To prevent the obstacles near the predefined path, the proposed guidance law is augmented by integrating the repelling field of obstacles so that it can control the ship travel toward the predefined path through the obstacles safely. The repelling field function is given considering the obstacle shape and collision risk using the velocity obstacle (VO) algorithm. The simulations and ship model test were performed to validate the integrated system of autonomous ships.

scholarly journals Robust path-following control design of heavy vehicles based on multiobjective evolutionary optimization

2021 ◽  
pp. 116304
Author(s):  
Gustavo A. Prudencio de Morais ◽  
Lucas Barbosa Marcos ◽  
Filipe Marques Barbosa ◽  
Bruno H.G. Barbosa ◽  
Marco Henrique Terra ◽  
...  
Keyword(s):  
Control Design ◽  
Path Following ◽  
Evolutionary Optimization ◽  
Heavy Vehicles ◽  
Path Following Control

Global path-following control of underactuated ships under deterministic and stochastic sea loads

Robotica ◽  
2015 ◽  
Vol 34 (11) ◽  
pp. 2566-2591 ◽  
Author(s):  
K. D. Do
Keyword(s):  
Lyapunov Functions ◽  
Velocity Potential ◽  
Path Following ◽  
Direct Methods ◽  
New Method ◽  
Moving Frame ◽  
Mean Values ◽  
Path Following Control ◽  
Projection Functions ◽  
The Mean

SUMMARYThis paper presents a new method to design global path-following controllers for underactuated ships under both deterministic and stochastic sea loads. The path-following errors are first interpreted in a moving frame attached to the path. These errors are then to be stabilized at the origin by a design of controllers based on backstepping and Lyapunov's direct methods. Weak and strong nonlinear Lyapunov functions are introduced to overcome difficulties caused by underactuation and Hessian terms induced by stochastic differentiation rule, and to guarantee boundedness of the sway velocity. Potential projection functions are introduced to design update laws that provide bounded estimates of the mean values and covariances of the disturbances. Simulations are included to illustrate the effectiveness of the proposed approach.

Path Following Control of Tractor-trailers with Off-axle Hitching

2010 ◽  
Vol 36 (9) ◽  
pp. 1272-1278 ◽  
Author(s):  
Huo-Feng ZHOU ◽  
Bao-Li MA ◽  
Li-Hui SONG ◽  
Fang-Fang ZHANG
Keyword(s):  
Path Following ◽  
Path Following Control
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