Modeling and Identification for Vector Propulsion of an Unmanned Surface Vehicle: Three Degrees of Freedom Model and Response Model

Abstract

This paper presents a complete scheme for research on the three degrees of freedom model and response model of the vector propulsion of an unmanned surface vehicle. The object of this paper is “Lanxin”, an unmanned surface vehicle (7.02 m × 2.6 m), which is equipped with a single vector propulsion device. First, the “Lanxin” unmanned surface vehicle and the related field experiments (turning test and zig-zag test) are introduced and experimental data are collected through various sensors. Then, the thrust of the vector thruster is estimated by the empirical formula method. Third, using the hypothesis and simplification, the three degrees of freedom model and the response model of USV are deduced and established, respectively. Fourth, the parameters of the models (three degrees of freedom model, response model and thruster servo model) are obtained by system identification, and we compare the simulated turning test and zig-zag test with the actual data to verify the accuracy of the identification results. Finally, the biggest advantage of this paper is that it combines theory with practice. Based on identified response model, simulation and practical course keeping experiments are carried out to further verify feasibility and correctness of modeling and identification.

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

“…Adequate sensing capabilities are generally required to enhance the performance of the USV. The inertial measurement unit (IMU) and global positioning system (GPS) as the basic sensors are typically used in combination with the system to guarantee the USV remaining in good operating condition, and to improve its performance [25]. The IMU/GPS is used to estimate the position and orientation of the USV during sailing.…”

“…Because of the sufficient longitudinal and lateral metacentric height of the USV, the motion of roll and pitch can also be ignored. Therefore, the six-DOF model can be simplified to a three-DOF model to describe the planar motions of USV in surge, sway and yaw [25], as shown in Figure 3.…”

State-of-the-Art Research on Motion Control of Maritime Autonomous Surface Ships

“…The establishment of a ship's motion model is very important for effective motion control. In terms of ship motion models, most studies build a model based on three degrees of freedom (3-DOF), or add roll control to build a 4-DOF model, very few of which are 6-DOF models [42][43][44][45], as shown in Figure 3. The model categories used are usually based on the hydrodynamic model and responsive model.…”

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

“…USV (Unmanned Surface Vehicle) is a novel kind of multifunctional surface platforms, which has recently received considerable attention from the control communities and oceanic application departments [ 1 , 2 , 3 ]. In recent years, different USVs are fabricated by dozens of universities and research institutes of ocean technology around the world, such as MIT and Woods Hole Oceanographic Institution, which have been applied in many oceanic fields, such as bathymetry [ 4 ], environment monitoring [ 5 ], underwater acoustics [ 6 ], marine rescue [ 7 ], and goal tracking [ 8 , 9 ].…”

“…The models of USVs are usually adopted as three DOF (Degrees of Freedom) equations in horizontal or four DOF equations by adding the roll motion [ 1 , 10 , 11 ], which are similar to modeling for conventional large crafts. However, due to hull type, displacement, and operation manner’s diversity, there are some differences between large crafts and small USVs’ motion model and control.…”