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This paper deals with the design of an autopilot based on sliding mode control combined with feedback linearization method for an autonomous sailing vessel. This autopilot is developed using a model with four degrees of freedom, which represents the dynamic of a sailboat. Due to the high nonlinearity of the developed dynamic model, heading and sail opening angle controller were developed to steer the sailboat toward a specific target position. The nonlinear four degrees of freedom dynamic model for the sailing vessel is first described. Then, an autopilot is designed using both sliding mode control and feedback linearization method. Finally, some simulations are carried out to illustrate the behavior of the overall system.

The fouling is a major problem that occurs to the ship's hull. This phenomenon causes severe economic and ecological consequences of shipping activities. Therefore, several robotic solutions were developed to mitigate fouling problem and to robotize hull-cleaning process. However, the existing solutions are either slow remotely operated vehicles or fast - but non-transportable - cleaning station equipped with manipulator's arms. In this paper, we aim to combine the transportability of the remotely operated vehicle solution and the cleaning efficiency offered by the use of arm manipulators. Hence, we present an innovative design of an underwater ship hull-cleaning robot called ARMROV by attaching two-manipulator arms to a remotely operated vehicle. However, in this new design, the robot central part is subject to dynamic stability issues during the cleaning operation that are caused by coupling forces between arms and the central part. In order to evaluate perturbations on the center part of the ARMROV, the kinematic and the dynamic model of the manipulator's arms were developed performed using Khalil-Kleifinger and Newton-Euler methods respectively. The dynamic stability during the hull cleaning operation was studied and checked using dynamic equivalence approach. Simulations results proved the efficiency of the stability approach and the feasibility of the proposed solution. In conclusion, the suggested design represents a promising stable and efficient solution for hull underwater cleaning.

This paper describes a simplified method to modeling and parameters identification of an Unmanned surface vehicle USV. The USV is propelled by two thrusters allowing both control of speed and heading. The outputs of the studied system are variables that characterize the kinematics and the motion of the USV such as the speed, the heading, and the position in the horizontal plan. First a nonlinear model with three degrees of freedom is designed, then the parameters are calculated based on sea trials data. Finally the model is validated by simulation in order to perform some control methods in a future work.

Flight control systems are widely used in modern aircraft; they help pilot in steering their aircrafts. The wind force applied on the aircraft quadcopter body causes large drift angles. To remedy this issue, an efficient flight controller based on nonlinear controller for both high-level and low-level regulators was designed. These tow controllers were developed based on the quadcopter dynamic model. This approach is validated through simulation to show its effectiveness.

This work proposes an autopilot scheme for self-steering an Unmanned Surface Vehicle (USV) in terms of heading and speed control, route following and waypoints tracking. The majority of regulators developed in the literature only provide heading control, which is a considerable weakness since the drift effects due to wind and marine currents cause the USV to move away from the planned path. This work deals with this problem and firstly proposes a mathematical model with three degrees of freedom for simulating the USV behavior. Second, USV parameter are calculated experimentally, and then an autopilot system is designed letting the USV to rapidly and smoothly reach a desired path and remain precisely on it. The developed autopilot, which is based on sliding mode control, consists of two levels of regulation, low-level controller for speed and heading control and a high-level controller for generating the desired speed and heading according to two different navigation modes: waypoints tracking and/or path following. Experimental results are carried out to verify the effectiveness of the proposed autopilot in term of heading control for waypoints tracking.

The use of the underwater robot for ship hull cleaning is increasingly studied given the valuable operational, economic and environmental advantages that it offers. The Automatic Control and Marine Robotics Unit, within the Tunisian Naval Academy, has suggested a new underwater robot design that is equipped with two manipulating arms. The offered solution allows to combine a system portability with the improved cleaning efficiency offered by the manipulator arms. However, during underwater operation, the robot, located beneath the ship's hull, is exposed to several perturbation forces. These forces are mainly caused by water current and waves. This research focuses on the robot static and dynamic stability when it is exposed to external perturbations. The proposed approach to ensure the robot stability consists in improving its mechanical design. Therefore, we developed the design of the scaled robot to eliminate static behavior. The dynamic model was established and the electronic architecture was described. Besides, the control scheme was proposed. In conclusion, our study demonstrates the importance of the mechanical symmetry design and the control law to ensure the stability of the underwater robot.

In recent years, there has been a great deal of interest in hybrid propulsion systems that provide power improvement solutions for watercraft. In order to be able to exploit the hybrid propulsion systems, one must first understand the principles of operation, its constituents as well as the parameters that influence its production and the means to control them. It is also essential to classify different types of batteries and panels according to their applications and environments. Our study will focus on the use of fuel cell, photovoltaic panels, a generator and a battery in the propulsion of a ship, which will choose an electrical topology that meets the constraints imposed. To realize a good exploitation of the hybrid system it is necessary to study all the equipment and to highlight the parameters on which they depend. Hence, it is necessary to think about the use of various sources to power ship propulsion system and that will allow better performance and strengthen navigation security. In this paper, we firstly studied, series and parallel hybrid propulsion configurations. Then we established the modeling of this system. Finally, we gave a numerical simulation of the proposed hybrid propulsion system operation.

This paper proposes a robust adaptive controller for the trajectory tracking of an autonomous surface vehicle (ASV) in the presence of model uncertainties, ocean currents, and time-varying environmental disturbances. First, a novel adaptive virtual velocity command is designed to estimate and compensate the unknown ocean currents acting on the ASV. Then, an improved torque controller is derived by applying filter operations and a set of auxiliary variables to avoid measuring the acceleration signals. To address the unknown dynamics parameters, a modified adaptive law with an alternative leakage term containing the parameter estimation error is developed. With this adaptive law, the convergence of both the estimated parameters and the tracking error can be achieved simultaneously. The whole closed-loop system's stability under environmental disturbances and parameter uncertainties is proved by the Lyapunov stability theory. Comparative simulations are carried out to validate the effectiveness of the proposed method.

This paper addresses the problem of fault detection and isolation in an asynchronous machine. We are interested in the study of linear systems with linear parameters variant LPV with polytopic structure. We present the methods of residual generator constructs for fault detection and isolation. The convex polytopic representation is obtained directly from the sum of linear mathematical models achieved by parametric variation of the model. Our approach is based on the application of Lyapunov's theorem and the utilization of LMI in order to satisfy the stability of observers. The default detection is based on the synthesis of the observers with unknown input. The method developed in this work has been applied on an asynchronous machine on which faults have been created. The numerical results confirm our study approach.

This paper deals with electrical energy from multi-sources intended to feed a propulsion system of a boat. These energy sources consist of photovoltaic panels, fuel cells, supercapacitors and accumulator batteries. A study of different topologies of connections between these different sources and the propulsion engine of the boat allowed to retain the continuous Bus topology. In this work, we present the modeling of each energy source associated with its converter, as well as the dimensioning of these elements. Then, we give the overall electrical diagram with the different sources and the associated electrical converters which are all connected to a continuous Bus. This Bus feeds the synchronous propellant motor through a three-phase pulse-modulated control inverter. Numerical simulations were carried out in this work.

The underwater hull cleaning is a center of interest of a big number of researchers from the fifties. Here we aim to facilitate the cleaning of the hull using a new robotic system with an arm manipulator. We developed the geometric and the dynamic modeling of the station components. In fact, the station has seven degrees of freedom four rotations and three translations. Besides, we used the SimMechanics software for the dynamic simulation of the station. In conclusion, our study shows that the underwater station with arm manipulator can be important for the hull cleaning operation.

One of the significant design stages of the ship electric propulsion system is the determination of the electric power and the propeller selection, which must fulfill the exploitation requirements of the ship, it performances and it physical characteristics. This choice is based mainly on the concern of overcoming the ship's total resistance under the projected operating conditions. So, we wrote three algorithms under Matlab that estimates the electric power that must be installed on board. First, the ship resistance is determined. Then, the effective power is estimated and finally the appropriate choice of the propeller is done taking into account the cavitations phenomena. The three algorithms are named in order: the propeller optimization program, the power prediction program and the propeller characteristic curves: calculation and visualization program. The numerical results obtained in this paper confirm our approach.

This paper focuses on the design and validation of an active Fault Tolerant Control (FTC) approach dealing with sensor and actuator faults for a ship propelled by two water jets. The proposed FTC relies on an adaptive estimation to reconstruct sensor faults and a second order sliding mode observer based on an adaptive super twisting algorithm to reconstruct the actuator faults. A nonlinear model of the considered ship, issued by a previous work, is used to prove the effectiveness of the proposed FTC in the path following maneuvers, speed regulation, and tracking course. The inputs of this model are the command orders to apply to the water jets including the two engines, the steering and reversing units for each jet. Details of the design process of the faults reconstruction and reconfiguration are given. The stability of the closed-loop system and uniform boundedness of the tracking error are proved based on Lyapunov theory. Simulations with many faults scenario are carried out. Results show that the proposed controller can successfully accommodate faults associated with sensors and actuators.

The ship propulsion system is a nonlinear and uncertain system. To overcome these constraints, in order to synthesize a powerful command, the multimodel control is promising. This paper deals with the modeling and multimodel control of complex uncertain systems. The approach is based on the principle of generating model bases, which can be local or generic, determined according to procedures using Kharitonov’s algebraic approach. The evaluation of the relevance of the models is ensured by means of validations calculated on line by referring to the responses of the process. Such validities are used to generate the multimodel control according to a strategy by fusion. Two fusion methods are then proposed: A merge at the level of the elementary commands and another at the level of the control parameters. This work deals with the development of a model base, as well as the synthesis of a multimodel control law. In this sense it is proposed to study the electric propulsion of ships as well as its composition. Next, we propose a technique for modeling the electric propulsion system of a ship and synthesized a multimodel control law. Finally, we will model the propulsion system based on a synchronous motor with permanent magnet and synthesize a law of control according to the multimodel approach.

Intermittency of renewable resources represents a major impediment that restricts their integration in microgrids. This paper presents an approach that can contribute to solve this issue by the prediction of near-term future renewable power production, mainly wind power and photovoltaic power, based on weather forecasts. After knowing the future renewable power production, the electric grid manager needs to find the optimal operating plan in order to efficiently integrate the predicted renewable production and to optimally operate other controllable components of the microgrid such as fuel-based generators, energy storage units and connectors to the commercial electric grid. We formulate this optimization problem as an integer linear program and exercise the model to study a number of practical issues surrounding microgrids.

This paper considers the issue of controlling of a ship propelled by two water jets in the presence of actuator faults. A second order sliding mode observer (SOSMO) based on an adaptive super twisting algorithm, a non-linear adaptive observer (NLAO) and an adaptive Thau observer (ATO) are compared for actuator faults reconstruction. Associated to the selected observer, is a reconfigurable control law relying on a sliding mode controller (SMC) to propose an active Fault Tolerant Control (FTC) for speed regulation and heading tracking. The effectiveness of the proposed FTC is shown using a nonlinear model of the considered ship issued by a previous work. Details of the design process of the fault reconstruction and reconfiguration are given. The convergence of the observers and the uniform boundedness of the tracking errors are proved based on Lyapunov theory. A typical fault scenario simulation for a naval vehicle is considered. Comparison of simulation results shows that the three observers can isolate actuator faults and estimate their severity with a further advantage for the SOSMO one in reducing the chattering phenomenon. The proposed controller can successfully accommodate faults and reach the desired values with very good performances.

The electrical propulsion vessels are complex, multi variable and highly nonlinear. They require advanced controls ensuring good robustness in stability and performance. This paper focuses on modeling and sliding mode control of electric propulsion system of a ship insured by a double star synchronous motor. We propose a structure of sliding mode control performance which well be applied it to ship electric propulsion system. A numerical study simulation of the proposed control is presented. The simulation results have allowed us to analyze the behavior of the loop for various operating conditions of the system.

In this paper, a limited authority adaptive PD control method is proposed and applied to ship steering control. The controller is designed by using the Nomoto’s model and its ARMA description. Efficiency of the proposed control scheme is studied and illustrated by simulations carried out with linear and nonlinear models.

The computation of the optimal constant output feedback gains for linear multivariable systems with respect to a quadratic performance criterion is discussed. The purpose of this paper is to determine an appropriate feedback matrix and to stabilize the system by minimizing a quadratic cost using genetic algorithm.