Elsevier

Applied Ocean Research

Volume 104, November 2020, 102369
Applied Ocean Research

Numerical and experimental study on the maneuverability of an active propeller control based wave glider

https://doi.org/10.1016/j.apor.2020.102369Get rights and content

Highlights

  • An 8 degree-of-freedom mathematical model of the wave glider based on the active propeller control is proposed.

  • The maneuverability of the wave glider with the propeller based controller and the conventional rudder based controller are compared in simulations in terms of course response, course keeping and turning.

  • Sea trial with the propeller control based wave glider ǣSJTU Mouseǥ was conducted and presented.

Abstract

Wave glider is a revolutionary ocean surface autonomous vehicle, which has the ability to convert surface wave motion into forward propulsion. Theoretically, the endurance of the wave glider is unlimited because of the consistent wave energy resources in ocean. Therefore, it has a broad application prospect in ocean survey and observation. However, due to the characteristics of low speed, underactuation and weak maneuvering of the wave glider, the maneuverability is of great significance in improving the cruising efficiency. In this paper, an 8 degree-of-freedom (DOF) mathematical model of the wave glider based on the active propeller control is developed. The performances of two kinds of controllers, i.e., the propeller based controller and the conventional rudder based controller, are compared in simulations in terms of course response, course keeping and turning. Experiments were conducted in the wave tank with the active control based wave glider named “SJTU Mouse”. The results demonstrate that the propeller control based wave glider has better maneuverability than the conventional rudder control based wave glider. Finally, sea trial with the “SJTU Mouse” was also conducted, and the results show that the propeller control based wave glider can track the desired course and desired path well under the complex ocean disturbances.

Introduction

Today, numerous autonomous vehicles have been developed and deployed for ocean survey and observation, such as search and rescue, spill collection, surveillance, net placement, bathymetric map creation, transportation, exploration tasks, environmental monitoring, marine survey, etc. (de la Cruz Garcia et al., 2012). Considering the spatial and time scales of the ocean are very large, the duration of survey vehicles is very important. The traditional fixed-point buoy can not realize the mobile measurement at sea, and the measurement area is very limited. The cost of scientific research ship is too high to realize large-scale application. The widely developed underwater gliders in recent years such as Slocum (Simonetti and Jones, 2001), Spray (Sherman et al., 2001), Seaglider (Eriksen et al., 2001) and Deepglider (Osse and Eriksen, 2007) have disadvantages in terms of endurance and maneuverability. Therefore, people are eager to develop a kind of marine unmanned autonomous vehicle which is totally dependent on marine energy and is no longer limited by the extra energy. So it can realize large-scale and long-term autonomous observation at sea. In this paper, a new type of ocean survey vehicle, i.e., a wave glider, which has an infinite duration, is investigated.

Wave glider is a kind of totally wave driven unmanned ocean surface vehicle for persistent marine environment monitoring ([Daniel, Manley, Trenaman, 2011], Frolov, Bellingham, Anderson, Hine, 2011, Hine, Willcox, Hine, Richardson, 2009, Manley, Willcox, 2010, Olson, 2012, Smith, Das, Hine, Anderson, Sukhatme, 2011). The wave glider is a two-body vehicle consisting of a surface float connected to a submarine glider via a flexible tether (Manley et al., 2009), as shown in Fig. 1. It is demonstrated that the oscillatory motion of the water particles reduced with depth below the free surface. Therefore, when the float heaves with the surface wave, the submarine glider heaves relative to the water. In the heaving process, the hydrofoils are forced to rotate so that the lift is always forward independent of the wave direction (Wang et al., 2018a), as shown in Fig. 2. The wave energy propulsion system is purely mechanical, no electrical power is generated by the propulsion mechanism (Manley and Willcox, 2010). Equipped with solar panel and battery as well as some dedicated environmental sensors and the satellite communication components, the wave glider can be onshore controlled for a wide variety of applications with dedicated sensors, including acoustic data collection, communication gateway for subsurface systems, meteorological observation, fisheries management and field monitoring (Olson, 2012, [Wang, Tian, Peng, Luo, 2018]). However, the wave glider has a much more complex geometry and propulsion system with a dual-body structure and an array of hydrofoils for wave energy conversion. Wave glider dynamics are distinct from those of traditional single-body surface vehicle or underwater gliders for the coexistence of both ocean surface waves and current disturbances. Moreover, the velocity of a wave glider is low (below 2–3 knots) and uncontrollable, causing weak maneuvering, long time-lag (Wang et al., 2019a). Therefore, in order to make the wave glider give full play to its unique advantages and complete various tasks at sea, it is of great significant to study its control system so as to improve its maneuverability and control accuracy at sea.

In order to improve the performance of the wave glider control system to adapt to the complex marine environment, there are some researches on the advanced control strategy of the wave glider. Liao et al. (2016) analyzed the intelligent behavior characteristics of the wave glider, and designed the intelligent control system architecture based on the cerebrum basic function combination zone theory and hierarchic control method. Aiming at the steady-state error in path following tasks caused by current, a self-adapting PID guidance law was proposed. Based on the S-surface control method, an improved S-surface heading controller was proposed to solve the heading control problem of the weak maneuvering carrier under large disturbance. On this basis, for the ǣrudder zero driftǥ problem in trials, Liao et al. (2017) proposed an improved S-surface control method based on rudder angle compensation, which can compensate the adverse effects from environmental forces and installation error. Wang et al. (2018a) proposed the dynamic linearized model of the wave gliders multiheading system. The corresponding dynamic correction method of the dynamic linearized model was also proposed. Moreover, the heading information fusion strategy was proposed to help solve the course control problem of the wave glider. Then the feasibility and validity of the proposed course control method of the wave glider was verified by simulation experiments and sea trials. Wang et al. (2019b) considered the limited energy supply in engineering application, the wave glider can not be controlled continuously for a long time. Therefore, a robust control strategy is needed to reduce energy consumption and maintain a certain control accuracy. In their study, a robust path following approach based on the LOS algorithm and restricted circle for the wave glider was proposed. An 8 degree-of-freedom (DOF) mathematical model and a PID heading controller in series with the proposed guidance strategy for wave glider path following control was established. Finally, the path following performances of the wave glider under various environment conditions were investigated.

Although the above literatures have carried on some explorations for the navigation control of the wave glider, and put forward some improved control strategies, which have improved the control performance to a certain extent. However, previous studies have all focused on the wave glider based on rudder control, which is a passive way of course control, greatly disturbed by the environment. In this paper, an active propeller control based wave glider is proposed. The propeller based controller will consume more energy than the rudder based controller for a long voyage. However, when the wave glider encounters an emergency, or the solar energy is sufficient, the propeller based controller can be adopted if the propeller based controller can significantly improve the maneuverability of the wave glider at sea. An 8-DOF mathematical model of the wave glider based on propeller control is developed in this work. A propeller control based wave glider named “SJTU Mouse” was built, and the experiments were conducted in the wave tank of Shanghai Jiao Tong University. Then the maneuverability of the wave glider based on propeller control and that based on rudder control were compared in simulation in terms of course response, course keeping and turning. Finally, the sea trial was also conducted.

The remainder of this paper is organized as follows. First, the modeling of the wave glider is introduced in Section 2. The propeller based course control is presented in Section 3. Simulation and experiments for the wave glider based on propeller control and rudder control are presented in Section 4. Some concluding remarks and insights regarding the wave glider based on propeller control are summarized in Section 5.

Section snippets

Mathematical modeling of wave glider

To investigate the control performance with respect to the wave glider, an 8-DOF model is developed, including a 4-DOF model of the floater and a 4-DOF model of the submarine glider, respectively. The wave gliders corresponding coordinate systems are shown in Fig. 3. To facilitate the modeling, three right-handed coordinate systems are defined consisting of one inertial reference frame {n} and two body-fixed frames {b1} and {b2}. For the reference frame {n} with original point on set at any

Propeller based course control

Different from the traditional rudder based controller, the propeller based controller is adopted in this paper, as shown in Fig. 8. The PID algorithm is used in this work. The control procedure is shown in Fig. 9. PID controller is a linear controller that is widely used in the engineering field (Anderson, Blankenship, Lebow, 1988, [Åström, Hägglund, 2001]). The objective of the PID control in this paper is to constrain a process response to follow the input signal. The output is compared to

Simulation and experiment

The propeller based controller and the conventional rudder based controller are compared in terms of the course response, course keeping and turning ability. These two control methods are implemented using MATLAB/Simulink for simulation. In order to conduct experiment research, a propeller control based wave glider named “SJTU Mouse” was designed and built in Shanghai Jiao Tong University (SJTU), as shown in Fig. 11. Table 1 provides an overview of the characteristics of “SJTU Mouse”. In

Concluding remarks

In this paper, to improve the maneuverability of the wave glider, an active propeller control based wave glider is proposed. An 8-DOF mathematical model of the wave glider based on propeller control is developed. A propeller control based wave glider named “SJTU Mouse” was built, and the experiments were conducted in the wave tank of SJTU. Then the maneuverability of the wave glider based on propeller control and that based on rudder control were compared in simulation in terms of course

CRediT authorship contribution statement

Peng Wang: Conceptualization, Methodology, Software, Validation, Data curation, Writing - original draft. Daoyong Wang: Data curation, Visualization, Writing - review & editing. Xiantao Zhang: Validation, Writing - review & editing. Xin Li: Resources, Writing - review & editing. Tao Peng: Resources, Writing - review & editing. Huimin Lu: Writing - review & editing. Xinliang Tian: Resources, Supervision, Writing - review & editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgement

The authors would like to thank the supports from Natural Science Foundation of Shanghai (Grant No.19ZR1426300), Shanghai Pujiang Program (Grant No. 19PJ1405400), National Natural Science Foundation of China (Grant Nos. 11632011, 51779141), Shanghai Innovation Action Plan of Science and Technology (Grand No. 19DZ1207300). All the numerical simulations are supported by center for High Performance Computing, Shanghai Jiao Tong University.

References (24)

  • T.I. Fossen

    Guidance and control of ocean vehicles

    University of Trondheim, Norway, Printed by John Wiley & Sons, Chichester, England, ISBN: 0 471 94113 1, Doctors Thesis

    (1999)
  • T.I. Fossen

    Marine control system-guidance, navigation and control of ships, rigs and underwater vehicles

    Marine Cybemetics

    (2002)
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