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In recent years, a large number of works have been presented that seek to solve the problem of road following by autonomous surface vehicles (ASV). In this sense, a non-linear guidance algorithm (NLGL), which has emerged in recent years for use in aerial vehicles, is presented as an interesting option for path tracking by marine vehicles as it does not use the yaw angle to achieve its objectives. control objectives. The biggest problem that these vehicles present when following paths is the influence of environmental disturbances on them, mainly sea currents and wind. To provide a solution to this problem, this paper presents a guidance and control scheme to achieve the following of straight paths by marine vehicles. It presents a cascade structure with an internal yaw velocity loop, which presents a PI controller as the main element, and the NLGL algorithm in the external loop. Thus, achieving that the vehicle follows a straight path with zero error without the need to measure the yaw angle and avoiding the implementation of an integral action in the external loop. An analysis is made of how the marine currents and the wind influence this system from the linearization of the presented scheme, in addition to a stability analysis of the scheme is presented. Finally, the results of simulation and real experiments of the implementation of this scheme in a small ASV are presented, where the vehicle converges to the desired trajectory with precision in the presence of environmental disturbances. [ABSTRACT FROM AUTHOR]

In recent years, a large number of works have been presented that seek to solve the problem of road following by autonomous surface vehicles (ASV). In this sense, a non-linear guidance algorithm (NLGL), which has emerged in recent years for use in aerial vehicles, is presented as an interesting option for path tracking by marine vehicles as it does not use the yaw angle to achieve its objectives. control objectives. The biggest problem that these vehicles present when following paths is the influence of environmental disturbances on them, mainly sea currents and wind. To provide a solution to this problem, this paper presents a guidance and control scheme to achieve the following of straight paths by marine vehicles. It presents a cascade structure with an internal yaw velocity loop, which presents a PI controller as the main element, and the NLGL algorithm in the external loop. Thus achieving that the vehicle follows a straight path with zero error without the need to measure the yaw angle and avoiding the implementation of an integral action in the external loop. An analysis is made of how the marine currents and the wind influence this system from the linearization of the presented scheme, in addition to a stability analysis of the scheme is presented. Finally, the results of simulation and real experiments of the implementation of this scheme in a small ASV are presented, where it can be seen that the vehicle converges to the desired trajectory with precision in the presence of environmental disturbances. [ABSTRACT FROM AUTHOR]

The unmanned surface vehicles have been used most frequently in recent years in different applications, like environmental research. For this vehicles to accomplish their autonomous missions, a path-following algorithm is necessary to reduce the cross-track error in the presence of environmental disturbance. This article presents a control scheme based on the path-following nonlinear guidance law for a small unmanned surface vehicle called Krick Felix which follows a straight path. A dynamic model of 3 degrees of freedom for this vehicle is presented. The control scheme consists of a cascade control loop that is capable of guaranteeing zero cross-track error in the presence of environmental disturbance without adding an integral action. A nonlinear Lyapunov stability analysis is carried out for this control scheme taking in consideration the dynamics of both the inner loop and the external loop. The simulation was realized by implementing the 3-degree-of-freedom nonlinear model of the Krick Felix. The simulation also took account of the environmental factors, that is, marine currents. An experimental test is carried out with the Krick Felix where the control scheme present satisfactory results. [ABSTRACT FROM AUTHOR]