Ship Steering Research Articles

Analysis of the Suboptimal Performance of the Steering Gear on MT. Narpatisuta

The steering gear is one of the auxiliary machineries on board a ship that is used to move the ship's rudder, allowing the ship to turn to the right or left. This machinery utilizes an electro-hydraulic system, which combines electric and hydraulic technologies to control the ship's steering direction. The research focuses on analyzing the suboptimal performance of the steering gear on the MT. Narpatisuta. The objectives of the research are to identify the factors causing the suboptimal performance of the steering gear, the impacts resulting from this suboptimal performance, and the efforts made to address the suboptimal performance of the steering gear on the MT. Narpatisuta. The research method used is a qualitative descriptive method, with data collection techniques in the form of observation, interviews, documentation and literature study. The data analysis technique uses the SHEL method. Test the validity of the data using triangulation. The research results show that suboptimal performance of the steering gear is caused by hydraulic pipe leaks, deteriorating quality of hydraulic oil, and damage to seal and o-ring components, which lead to reduced steering gear performance, slower rudder movement, and can disrupt ship operations, endangering crew safety and the ship's cargo. Efforts that can be made to remedy this include routine inspection and maintenance of the steering gear and its components. Thus, this research emphasizes the need for routine inspection and maintenance to prevent these problems which must ensure maximum steering gear function, maintain safety and ship operational efficiency.

The control method for ship tracking when navigating through narrow and curved sections

A track control method is proposed to solve the problem of manual steering difficulties in narrow and curved sections. The performance of a ship heading controller is affected by various factors, such as delay of the ship steering gear, external environmental disturbances, and variations in ship's speed. Firstly, a Smith optimal PID heading controller is designed. Then, a speed control method based on dichotomous method is proposed to accurately control ship speed and improve the rudder efficiency. Finally, a track control method based on model prediction and feedback compensation is proposed, considering the coupling relationship between course control and speed control. The Lantang Channel is selected as the experimental water area, and comparative simulation experiments are carried out under static water and environmental disturbance. The pre-planned route information is taken as input, and the target course at the current moment is calculated by the guidance method. The target course is used as the input of the course controller to calculate the rudder angle to control the ship's motion, and the new ship position is compared with the planned route information. The above steps are repeated to track the planned route. In order to make the ship pass the curve smoothly, the target speed of the control point is preset according to the sailing convention of decelerating first and accelerating later, and the variable speed time point and variable telegraph are solved by the dichotomy. The results are as follows: (1) The maximum track deviation and speed deviation of the Smith-OP PID are 2 m and 0.21 kn, respectively, without considering environmental interference. The maximum track deviation of the traditional PID is 8 m. (2) The maximum track deviation and speed deviation of the Smith-OP PID are 25 m and 0.27 kn, respectively, under the set environmental interference. The maximum track deviation of the traditional PID is 49 m. (3) The track control method is consistent with the practical practices of "deceleration before acceleration" and "hanging high and taking low". In summary, the track control method can be well applied to narrow and curved sections, and provide a theoretical basis for subsequent research on autonomous navigation and intelligent ships.

ARDUINO-BASED SHIP STEERING SIMULATION BY COMPARING INCREMENTAL ROTARY ENCODER SENSOR WITH INFRARED SENSOR

In vocational institution, practicum activities can be done by using a bridge simulator, such as in the nautical study program, which has a steering component in the simulator. In our engineering study program, we tried to design a ship steering simulation by comparing an incremental rotary encoder sensor with an infrared sensor to determine the direction and degree of rotation. The steering gear is a very important tool of a ship because it determines the safety of the ship. Therefore, the rudder must meet the requirements set by SOLAS 74 rule 29 Chapter II regarding steering gear. When the ship is traveling at maximum economic speed, the main steering gear must be able to steer 35 degrees to the left/right within 28 seconds. In connection with this, we wanted to design, build, and manufacture a tool that can simulate ship steering. This simulation tool that we have designed generally has several capabilities such as being able to steer the ship from 35 degrees port to 35 degrees starboard, or vice versa, during maximum engine speed and load in a maximum period of 28 seconds. [1] Arduino is used to process data from incremental rotary encoder sensors and infrared sensors which will be sent via serial USB to the computer. Rotary encoders and infrared are used to determine how many degrees the ship will turn right or left, both are compared in terms of time and accuracy. To display a ship's steering simulation, a visual basic application is used to display a ship's movement simulation, ship's steering and ship's rudder.

Nonparametric Modeling and Control of Ship Steering Motion Based on Local Gaussian Process Regression

This paper aims to study the nonparametric modeling and control of ship steering motion. Firstly, the black box response model is derived based on the Nomoto model. Then, the establishment of a nonparametric response model and prediction of ship steering motion are realized by applying the local Gaussian process regression (LGPR) algorithm. To assess the performance of LGPR, two cases are studied, including a Mariner class vessel by using simulation data and a KVLCC2 tanker model by using experimental data. The results reveal that the response model identified by LGPR presents good prediction accuracy and low computational burden. Finally, the identified response model is used as the basis for developing the ship heading controller, and the results demonstrate that the proposed controller is able to achieve good dynamic performance.

An investigation into the gate rudder system design for propulsive performance using design of experiment method

ABSTRACT The Gate Rudder System (GRS) is an innovative energy-saving device integrating the steering and propulsion of ships. Despite demonstrated potential, optimal GRS design remains underexplored. This study used a Design of Experiment (DoE) approach to investigate the sensitivity of key design variables of the GRS on the ship's powering performance. Computational Fluid Dynamics (CFD) analysis was employed to calculate the respective flow variables at each design point, and the most effective geometrical parameter was identified as the rudder angle based on the correlations. Surprisingly, the analyses revealed that the best powering performance was not observed with the highest rudder thrust force generated. Instead, the optimal design was found to be one that maximizes the overall energy savings by achieving the most favorable interaction between the propeller, hull, and GR. High-fidelity CFD validates results. This study bridges the gap in GRS design for powering efficiency, contributing to technology's performance optimisation.

파랑 관측시스템 구축 및 선박 조종 알고리즘 설계

파랑 관측시스템 구축 및 선박 조종 알고리즘 설계

Soft Computing Based Sliding Surface Adjustment of Second Order Sliding Mode Controllers: An Application to Ship Steering Model

Soft Computing Based Sliding Surface Adjustment of Second Order Sliding Mode Controllers: An Application to Ship Steering Model

Observer-based [formula omitted] fuzzy fault-tolerant switching control for ship course tracking with steering machine fault detection

To enhance the robustness of ship autopilot (SA) system with nonlinear dynamics, unmeasured states, and unknown steering machine fault, an observer-based H∞ fuzzy fault-tolerant switching control for ship course tracking is proposed. Firstly, a global Takagi–Sugeno (T-S) fuzzy nonlinear ship autopilot (NSA) is developed with full consideration of ship steering characteristics. And the actual navigation data collected from a real ship are used to verify the reasonableness and feasibility of NSA model. Then, virtual fuzzy observers (VFOs) for both fault-free and faulty systems are proposed to estimate the unmeasured states and unknown fault simultaneously, and compensate for the faulty system by using the fault estimates. Accordingly, the VFO-based H∞ robust controller (VFO-HRC) and fault-tolerant controller (VFO-HFTC) are designed. Subsequently, a smoothed Z-score-based fault detection and alarm (FDA) is developed to provide switching signals for which the controller and its corresponding observer should be invoked. Finally, simulation results on the “Yulong” ship demonstrate the effectiveness of the developed control method.

Fuzzy fault tree analysis for loss of ship steering ability

Marine accidents have devastating effects on human life, the environment, and the economy. This study investigated the root causes of accidents resulting from the loss of a ship steering ability using Fuzzy Fault Tree Analysis (FFTA). Failure of the steering gear's hydraulic power, failure of the rudder, and failure of the steering gear's control are the three most common causes of loss of ship steering ability. Due to the difficulty in obtaining exact probabilities, the linguistic judgments of experts were used to determine the probabilities of each event's occurrence. The results showed that "steering gear hydraulic power failure" has the highest occurrence probability, followed by "rudder failure" and "steering gear control failure" in descending order. The occurrence probability of the top event, loss of steering ability, was calculated as 4.86E-02. An examination of the minimum cut set (MCS) identified "oil leaking through sealings to surrounding" as the most dangerous event. The MCS with the lowest occurrence probability was a combination of a main power supply failure and an emergency power supply failure. The findings of this study have made substantial theoretical and applied contributions to maritime safety, environmental protection, and the global economy.

Learning-Based Nonlinear Model Predictive Controller for Hydraulic Cylinder Control of Ship Steering System

The steering mechanism of ship steering gear is generally driven by a hydraulic system. The precise control of the hydraulic cylinder in the steering mechanism can be achieved by the target rudder angle. However, hydraulic systems are often described as nonlinear systems with uncertainties. Since the system parameters are uncertain and system performances are influenced by disturbances and noises, the robustness cannot be satisfied by approximating the nonlinear theory by a linear theory. In this paper, a learning-based model predictive controller (LB-MPC) is designed for the position control of an electro-hydraulic cylinder system. In order to reduce the influence of uncertainty of the hydraulic system caused by the model mismatch, the Gaussian process (GP) is adopted, and also the real-time input and output data are used to improve the model. A comparative simulation of GP-MPC and MPC is performed assuming that the interference and uncertainty terms are bounded. Consequently, the proposed control strategy can effectively improve the piston position quickly and precisely with multiple constraint conditions.

A Vulnerability Criterion of Dynamic Instability for Ship Course-Keeping in Following Waves

_ A practical criterion which can be used for assessing the course-keeping capability of a ship in following waves, is proposed and evaluated. Presently, it accounts for regular waves and it accrued from an analytical estimation of the course instability region’s boundary by applying the method of harmonic balance. The calculation is performed with regard to the third-order yaw equation, derived from a classic sway-yaw-rudder model of ship maneuvering motions, with time-dependent coefficients at two places, which is like a Mathieu-type equation extended to third order. The proposed analytical criterion was evaluated thoroughly against simulations with regard to this sway-yaw model and it was found to be adequately accurate. A supplementary quasi-static yaw stability criterion (fitting to ship operation with frequency of encounter, with respect to the waves, close to zero) was also considered in order to determine which one yields more stringent requirements, for various operating conditions. The proposed criterion could be an extra vulnerability check for broaching-to, in the context of the Second Generation Intact Stability Criteria. Introduction The difficulties of steering of ships in following seas have received the attention of the research community since more than 70 years ago (Davidson 1948). A relevant direction of research refers to the avoidance of the broaching-to instability and, in particular, to the development of practical criteria that could ensure sufficient course-keeping capability for a ship encountering steep following waves. Some classic works on this topic, such as those of DuCane and Goodrich (1962), Wahab and Swaan (1964), and Motora et al. (1981), were focused on the quasi-static condition of a ship on the wave which could be practically realized if the ship was advancing with speed equal to the wave celerity (zero frequency of encounter). As implied, these works were essentially focused on the avoidance of a type of broaching-to instability that is preceded by the realization of surf-riding, a phenomenon where the ship is forced to move with the wave, usually riding a downslope.

A two-stage dynamic collision avoidance algorithm for unmanned surface vehicles based on field theory and COLREGs

This studies the dynamic collision avoidance (CA) problem of unmanned surface vehicle (USV) under the International Regulations for Preventing Collisions at Sea (COLREGs, short for Collision Regulations). A more realistic virtual spatial velocity field and two-stage CA area are proposed to reflect the movement of the target ship (TS), and the heading state of the USV is divided into a safe state and an emergency state. A decision model of ship steering for CA by analyzing the obligatory behavior of giving way to ships in the COLREGs is proposed. First, in the safe state, a novel of CA algorithm is proposed by using particle swarm optimization (PSO) and the problems of avoiding the TS and sailing to the destination are considered simultaneously. Second, in the emergency state, a new CA algorithm is developed by combining the decision model of ship steering for CA with the artificial potential field (APF) method, when considering avoiding the TS. Finally, the effectiveness of the algorithms are proved by simulation.

Scaled Consensus and Reference Tracking in Multiagent Networks With Constraints

This paper considers the scaled consensus problem for networks of groups of agents having state constraints. We first address the problem by using a gradient projection approach and design distributed consensus protocols that implement state restriction and steer agents asymptotically to proportions in terms of pre-assigned scales. We then extend the method to multiagent systems with static reference values. We propose and analyze sufficient conditions on agent dynamics such that scaled reference tracking problem is solved. The results are applied to a ship steering system and numerical examples to verify the effectiveness of the proposed cooperative coordination system scheme.

Ship Steering Adaptive CGS Control Based on EKF Identification Method

In recent years, marine autonomous surface vessels (MASS) have grown into a ship research issue to increase the level of autonomy of ship behavior decision-making and control while sailing at sea. This paper focuses on the MASS motion control module design that aims to improve the accuracy and reliability of ship steering control systems. Nevertheless, the stochastic sea and wind environment have led to the extensive use of filters and state observers for estimating the ship-motion-related parameters, which are important for ship steering control systems. In particular, the ship maneuverability Nomoto index, which primarily determines the designed ship steering controller’s performance, cannot be observed directly due to the model errors and the external environment disturbance in the process of sailing. Hence, an adaptive robust ship steering controller based on a closed-loop gain shaping (CGS) scheme and an extended Kalman filter (EKF) on-line identification method is explored in this paper. To verify the effectiveness of the proposed steering controller design scheme, the motor vessel YUKUN was taken as the control plant and a series of simulation experiments were carried out. The results show the advantages of the dynamic response performance of the proposed steering controller compared with the classical PD and traditional CGS controllers. Therefore, the proposed adaptive CGS steering controller would be a good solution for MASS motion control module design.

PE-A* Algorithm for Ship Route Planning Based on Field Theory

Route planning is the key to safe, efficient and intelligent navigation of maritime traffic. Autonomous route planning is a complex optimization problem, which requires both global route planning and local collision avoidance. In this paper, we propose an optimization algorithm which can consider both global route planning and local collision avoidance. Firstly, nonlinear constraint optimization models of obstacle limitation, safe water depth limitation and ship steering limitation are established. Then, the PE-A* algorithm and route planning framework are proposed by using potential energy field to accurately express the environment. Finally, the safety and feasibility of the route planned by PE-A* algorithm are discussed through simulation experiments. Simulation results show that PE-A* algorithm can realize both global route planning and local collision avoidance, and the safety and feasibility of the planned route are greatly improved. From the perspective of potential energy, this work proposes an automatic route planning algorithm and establishes a flexible mathematical model, which can add fuel consumption, time and other related engineering requirements into the model to plan the optimal route meeting the requirements.

Information Technology for Designing Rule bases of Fuzzy Systems using Ant Colony Optimization

This paper proposes the universal information technology for designing the rule bases (RB) with the formation of optimal consequents for fuzzy systems (FS) of different types on the basis of ant colony optimization (ACO) techniques. The developed ACO-based information technology allows effectively synthesizing rule bases of various dimensions both for the MISO and MIMO fuzzy systems taking into account the particular features of the RB consequents formation in the conditions of insufficient initial information. In order to study and validate the efficiency of the presented information technology the design of the RB for the adaptive fuzzy control system of the ship steering device is carried out in this work. The computer simulations results show that adaptive control system with developed RB provides achievement of high enough quality indicators of rudder angle control. Thus, application of the proposed ACO-based information technology allows designing effective RB with optimal consequents by means of minor computational costs that, in turn, confirms its high efficiency.

CFD-BASED HYDRODYNAMIC ANALYSIS FOR A SHIP SAILING ALONG A BANK IN RESTRICTED WATERS


 
 
 For a ship navigating along a bank in restricted waters, it is usually accompanied by obvious bank effect which may cause ship-bank collision. In order to avoid collision, it is necessary to provide control force and moment by using control devices such as a rudder. In this paper, CFD method is applied to numerically simulate the viscous flow around a ship appended with a rudder sailing along a bank. Systematical simulations are carried out for the hull-rudder system with different rudder angles at different ship-bank distances and water depths. The flow field features and the hydrodynamic forces of the hull-rudder system are obtained and analysed. This study is of significance for revealing the physical mechanism behind the bank effect and providing guidance for ship steering and control in restricted waters.
 
 

Design and Assessment of ADRC-Based Autopilot for Energy-Efficient Ship Steering

This paper looks at a typical problem encountered in the process of designing an automatic ship’s course stabilisation system with the use of a relatively new methodology referred to as the Active Disturbance Rejection Control (ADRC). The main advantage of this approach over classic autopilots based on PID algorithms, still in the majority, is that it eliminates the tuning problem and, thus, ensures a much better average performance of the ship in various speed, loading, nautical and weather conditions during a voyage. All of these factors call for different and often dynamically variable autopilot parameters, which are difficult to assess, especially by the ship’s crew or owner. The original result of this article is that the required controller parameters are approximated based on some canonical model structure and analysis of the hydrodynamic properties of a wide class of ships. Another novelty is the use of a fully verified, realistic numerical hydrodynamic model of the ship as a simulation model as well as a basis for deriving a simplified model structure suitable for controller design. The preliminary results obtained indicate good performance of the proposed ADRC autopilot and provide prospects for its successful implementation on a real ship.

Mathematical modeling and identification of surface vessel model parameters

The paper considers the problems of modeling and identification of parameters for models of surface ships. The proposed identification method is applied to a modified second order Nomoto model for ship steering. The identification algorithm is based on the Dynamic Regressor Extension and Mixing Method (DREM) that is performed in two steps. At the first stage parameterization is used for a regression model, in which the regressor and regression depend on the measured signals, namely, longitudinal, lateral and angular velocities and steering angle. At the second stage a new regression model is built using linear stable filters and delays. Finally, the parameters are estimated by the standard gradient descent method. The paper proposes a new algorithm which identifies the parameters for models of surface ships. The authors analyzed the prospects of the proposed estimating method by computer experiments. Experiments have shown the advantage of the method: when using the gradient descent method, the transient time spent to estimate the signal parameters is much longer than using the DREM method. At the same time, in the case of using the DREM method, there is no overshoot. The results of the work can serve as a basis for methods, algorithms and software for designing ship automated navigation systems and control systems for other modes of transport. This is confirmed by the simulation results.

Active disturbance rejection control of ship course keeping based on nonlinear feedback and ZOH component

To solve the problems of external disturbance, internal model uncertainty and rudder angle energy input to much in ship course keeping, an active disturbance rejection control algorithm based on nonlinear feedback is proposed. Firstly, the ADRC algorithm is designed to control the ship course, and the external disturbance and internal uncertainty are estimated by the linear state observer, and then the controller is compensated. In the process of navigation, “large rudder angle” and “high rudder frequency” will increase ship roll and rudder wear. Nonlinear feedback is used to modify the error to reduce the excessive input of rudder angle energy. Zero order holder is introduced to reduce rudder frequency and rudder wear. Finally, the simulation results show that the controller has well tracking effect. The nonlinear feedback with ZOH has smaller rudder angle and frequency. In severe sea state, high rudder frequency and high rudder amplitude will cause the wear of ship steering gear, excessive heeling and reduced stability, so the algorithm proposed in this paper is more secure and energy-saving.