The drawbacks of common nonlinear Filtered-ε adaptive inverse control （AIC） method, such as the unreliability due to the change of delay time and the faultiness existing in its disturbance control loop, are discuss...The drawbacks of common nonlinear Filtered-ε adaptive inverse control （AIC） method, such as the unreliability due to the change of delay time and the faultiness existing in its disturbance control loop, are discussed. Based on it, the diagram of AIC is amended to accommodate with the characteristic of nonlinear object with time delay. The corresponding Filtered-ε adaptive algorithm based on RTRL is presented to identify the parameters and design the controller. The simulation results on a nonlinear ship model of ＂The R.O.V Zeefakker＂ show that compared with the previous scheme and adaptive PID control, the improved method not only keeps the same dynamic response performance, but also owns higher robustness and disturbance rejection ability, and it is suitable for the control of nonlinear objects which have higher requirement to the maneuverability under complex disturbance environment.展开更多
As the maneuverability of a ship navigating close to a bank is influenced by the sidewall, the assessment of ship maneuvering stability is important. The hydrodynamic derivatives measured by the planar motion mechani...As the maneuverability of a ship navigating close to a bank is influenced by the sidewall, the assessment of ship maneuvering stability is important. The hydrodynamic derivatives measured by the planar motion mechanism （PMM） test provide a way to predict the change of ship maneuverability. This paper presents a numerical simulation of PMM model tests with variant distances to a vertical bank by using unsteady RANS equations. A hybrid dynamic mesh technique is developed to realize the mesh configuration and remeshing of dynamic PMM tests when the ship is close to the bank. The proposed method is validated by comparing numerical results with results of PMM tests in a circulating water channel. The first-order hydrodynamic derivatives of the ship are analyzed from the time history of lateral force and yaw moment according to the multiple-run simulating procedure and the variations of hydrodynamic derivatives with the ship-sidewall distance are given. The straight line stability and directional stability are also discussed and stable or unstable zone of proportional-derivative （PD） controller parameters for directional stability is shown, which can be a reference for course keeping operation when sailing near a bank.展开更多
It is well known that model test is one of approaches to investigate the maneuverability of vessels and the correlative method is an important problem of model test for vessels with large scale. Some of correlative pr...It is well known that model test is one of approaches to investigate the maneuverability of vessels and the correlative method is an important problem of model test for vessels with large scale. Some of correlative problems,which should be solved with care in model test,are presented from analysis of the similarity principle for the ship maneuverability in this paper.A corrective method of appropriate angle of rudder is provided based on the result of maneuverability model test for a tanker with large scale and the corresponding prediction of the maneuverability for full scale tanker is satisfactory in view of engineering practice.展开更多
The identification of ship collision risks is an important element in maritime safety and management.The concept of the ship domain has also been studied and developed since it was proposed.Considering the existing tr...The identification of ship collision risks is an important element in maritime safety and management.The concept of the ship domain has also been studied and developed since it was proposed.Considering the existing trend that the ship domain is increasingly widely used in collision risk-related research,a new domain-oriented collision risk factor,i.e.,the current state of domain(CSD),is introduced in this paper,which can effectively reflect the current state and show a certain predictability of collision risk from the perspective of the ship domain.To further prove the rationality of the CSD,a series of different simulations consisting of three typical encounter scenarios were conducted,verifying the superiority of the proposed parameter.展开更多
基金This project was supported by the National Defence Pre-research Foundation of Shipbuilding Industry (01J1.50) and theWeapon & Equipment Pre-research Foundation of General Armament Department (51414030204JW0322).
文摘The drawbacks of common nonlinear Filtered-ε adaptive inverse control （AIC） method, such as the unreliability due to the change of delay time and the faultiness existing in its disturbance control loop, are discussed. Based on it, the diagram of AIC is amended to accommodate with the characteristic of nonlinear object with time delay. The corresponding Filtered-ε adaptive algorithm based on RTRL is presented to identify the parameters and design the controller. The simulation results on a nonlinear ship model of ＂The R.O.V Zeefakker＂ show that compared with the previous scheme and adaptive PID control, the improved method not only keeps the same dynamic response performance, but also owns higher robustness and disturbance rejection ability, and it is suitable for the control of nonlinear objects which have higher requirement to the maneuverability under complex disturbance environment.
基金supported by the National Key Basic Research Program of China(Grant No.2014CB046804)
文摘As the maneuverability of a ship navigating close to a bank is influenced by the sidewall, the assessment of ship maneuvering stability is important. The hydrodynamic derivatives measured by the planar motion mechanism （PMM） test provide a way to predict the change of ship maneuverability. This paper presents a numerical simulation of PMM model tests with variant distances to a vertical bank by using unsteady RANS equations. A hybrid dynamic mesh technique is developed to realize the mesh configuration and remeshing of dynamic PMM tests when the ship is close to the bank. The proposed method is validated by comparing numerical results with results of PMM tests in a circulating water channel. The first-order hydrodynamic derivatives of the ship are analyzed from the time history of lateral force and yaw moment according to the multiple-run simulating procedure and the variations of hydrodynamic derivatives with the ship-sidewall distance are given. The straight line stability and directional stability are also discussed and stable or unstable zone of proportional-derivative （PD） controller parameters for directional stability is shown, which can be a reference for course keeping operation when sailing near a bank.
文摘It is well known that model test is one of approaches to investigate the maneuverability of vessels and the correlative method is an important problem of model test for vessels with large scale. Some of correlative problems,which should be solved with care in model test,are presented from analysis of the similarity principle for the ship maneuverability in this paper.A corrective method of appropriate angle of rudder is provided based on the result of maneuverability model test for a tanker with large scale and the corresponding prediction of the maneuverability for full scale tanker is satisfactory in view of engineering practice.
基金The National Natural Science Foundation of China(Grant No.51909022)Natural Science Foundation of Liaoning Province(Grant No.2019-BS-024)+1 种基金Research Program of Maritime Safety Administration of China(Grant No.0706-14400004N010)the Fundamental Research Funds for the Central Universities(Grant No.3132019347).
文摘The identification of ship collision risks is an important element in maritime safety and management.The concept of the ship domain has also been studied and developed since it was proposed.Considering the existing trend that the ship domain is increasingly widely used in collision risk-related research,a new domain-oriented collision risk factor,i.e.,the current state of domain(CSD),is introduced in this paper,which can effectively reflect the current state and show a certain predictability of collision risk from the perspective of the ship domain.To further prove the rationality of the CSD,a series of different simulations consisting of three typical encounter scenarios were conducted,verifying the superiority of the proposed parameter.
基金Supported by the Special Research Fund for the Doctoral Program of Higher Education (Grant No.20050248037)the National Natural Science Foundation of China (Grant No.10572094)
