基于标准建模的舰船试验备航训练系统研究

采用UML建模语言对舰船试验备航训练系统的设计进行了系统分析。运用实例阐明了标准化建模技术在建立舰船试验备航训练系统与动态模型中的应用,并给出了系统的用例图模型、流程图模型和顺序图模型。

蒸汽动力系统机动性影响因素分析

在分析舰艇机动性影响因素的基础上,研究了蒸汽动力系统机动性影响因素,分别从改变功率和工况方面考虑,对备航过程、全速前进到全速倒车过程进行分析,可为动力系统的操作使用提供指导,从而在保证装备安全的前提下提高动力系统的机动性。

基于流程仿真的物资接收系统可靠性预计方法

针对船舶物资接收时间计算的问题,新增加了对设备发生故障的考虑,通过引入接收时间可靠性的概念,将其转换为船舶物资接收系统的可靠性预计问题。为了解决上述可靠性预计问题,提出了基于流程仿真的系统可靠性预计方法。分析了物资接收系统的工作流程,依据工作流程实现了仿真程序,用蒙特卡洛法对物资接收系统的可靠性进行了求解,并分析了设备不同的可靠性水平对物资接收系统可靠性的影响。仿真结果表明,增加了对设备故障的考虑后,对物资接收时间的估计更加接近实际;基于流程仿真的系统可靠性预计方法的模型更容易理解,所得结论更加具体。

New concept research on mono-hull compounded ship form with high seakeeping performance

The seakeeping performance of a certain ship equipped with semi-submerged bow ( SSB) and bow-fins is discussed. The numerical calculations are carried out on a 600t deep-V compound archetypal ship. The results show that the compounded ship form has excellent seakeeping performance and thus it establishes the theoretical foundations for the development of mono-hull compounded ship form with high se akeeping performance.

Analysis of signal-obtaining error factor of sensor in gyro

The digital signal-obtaining for gyroscope is given. The single optic-fiber sensor via modulating intensity of light is used as measuring eonlponent . The influence on static transmission properties resulting from the special working environnlent （e. g. cryogenic and vacuum） ,the measure error because of tile reflector shape of rotor,the abnormity of facula from sensor caused by the existence of engraving error,and tile fixing error of sensor and the error of machine tool＇s initial lignnlent are investigated. The mathematic model in every condition is founded, the simulation and relative experiments ale done and the outeome is analyzed. The mathematic model and method of compensating technology are studied and some relative experiments are made. The result of study is usefid to improvement of the signal-obtaining system.

Research and Design of Drop Keel System for Multi-purpose Oceanographic Vessel

When an oceanographic vessel is sailing, the currents near the surface of ship hull are rapid, making it hard to meet the environmental requirements of scientific observation equipment. To guarantee the installation space and environmental requirements of the observation equipment, the drop keel system was proposed for the first time for ocean-graphic ships at China, to avoid the traditional ＂rudder-shaft＂ type fin keel＇s disadvantage. The research study will examine the operational mechanism and functions of the drop keel system, the operating conditions of the fin keel to determine the driver method and its arrangement, and the locking method of the fin keel underwater. The research wilI also provide some general designs for analyzing the best plan for the drop keel system.

Three-time rapid transfer alignment method of SINS/GPS navigation system of high-speed marine missile

The transfer alignment of SINS/GPS navigation system of a high-speed marine missile was investigated. With the help of the big acceleration of a high-speed missile, the transfer alignment was changed into a three-time alignment. The azimuth alignment was coarsely finished in 10s in the first time alignment, the horizontal alignment was accurately and rapidly finished in the second time alignment, and the azimuth alignment was accurately finished in the third time alignment. Because the second time alignment and the third time alignment were finished by GPS after the missile was launched, the horizontal alignment and the second azimuth alignment got rid of the influence of the warship body flexibility deforming. The precision and rapidity of the horizontal alignment were prominently increased due to the vertical launch of the marine missile with the big acceleration. Simulation verifies the effectiveness of the proposed alignment method.

The research on signal-obtaining pattern for a new type of gyroscope

In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.

Reviews and Expectations on the Maiden Voyage of a Chinese Merchant Ship in the Arctic Northeast Route

This paper introduces the preparatory work and conducts an integrated review on the maiden voyage of a Chinese commercial ship on the Arctic Northeast Route. It puts forth expectations on the exploitation and utilization of the Arctic Northeast Route in the aspects of safety, fastness, low costs, low consumption of energy and less pollution, knowledge of maritime law and navigation practice, building seaworthiness ships and making studies on the methods of sailing and maneuvering for navigation in polar waters, training qualified seafarers with navigation experiences in ice waters and establishing a safeguard system for the navigation in this route through the analysis on the weather, temperature, ice condition, route and hydrology encountered in the practice of a Chinese merchant ship in its maiden voyage in the route, and studies on the ice pilotage, convoy by icebreaker, practical condition of communication and navigation equipment in sea areas of high latitude and the economic benefit of the navigation in the Arctic Northeast Route.

Direct calculation of acceleration field through homogeneous transformation for two-axis centrifuge

A precision centrifuge is an inertial navigation test equipment used for calibrating the characteristics of accelerometers with high overloading, and a two axis centrifuge can be used to generate either constant acceleration or harmonic acceleration. The moving trajectory equation about the origin of the accelerometer coordinate system in a two axis centrifuge was directly deduced through homogeneous transformation. The acceleration vector of the origin in accelerometer coordinate system was achieved by making the second derivative of this trajectory equation. The acceleration components were acquired by decomposing this acceleration vector along the three axes of the accelerometer coordinate system. The correctness of the homogeneous transformation was verified through vector analysis.

Research on H_2 speed governor for diesel engine of marine power station

The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H, speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.

Electrostatic Suspension System Nonlinear Character Analysis and Its Internal Model Control

Nonlinearity is an important characteristic in electrostatic suspension system (ESS). This paper concludes the nonlinear parts in ESS, which generally result from the relationships between rotor displacement and capacitance, rotor displacement and electrostatic force, and control voltage and electrostatic force. In terms of the nonlinearities, a new control method with modified internal model control (IMC) was proposed to analyze the ESS, deduce the transfer function of the modified IMC controller in ESS, and simulate this new application in ESS. Comparing with proportional integral derivative (PID) control, IMC has only a parameter, and has better performance. As a result, IMC solves nonlinearity error well in ESS with only one uncertain parameter, and performs well when the rotor has large displacement.

Research and implementation of digital detection method on closed loop FOG

In the strapdown inertial navigation system, the Fiber Optical Gyro(FOG) must have high precision to give accurate navigation information. In this paper, a digital closed loop detection method based on the ramp wave modulating technigue is introduced. DSP and FPGA have many advantages in digital signal proeessing. In the design, by using DSP, a complex arithmetic operation is completed to meet the needs of closed loop control of FOG within a short time. All kinds of control signals are produced easily by FPGA, under which DSP could work properly. Combining the DSP and FPGA,the detecting method is implemented successfully. In the end, the result of test and performance is given. From the result we can conclude that the precision of FOG is improved and the noises are limited to a low level.

The Creative Application of DIY Manufacturing Technology in Remote Sensing Satellite

Based on the concept of DIY, this paper demonstrates the essential potential of DIY manufacturing technology in the application of space equipment. According to the future space technology development trends, the future spacecraft DIY idea and system standard are proposed. The standardized, modularized and serialized micro/nano-satellite DIY products are introduced. Finally, a commercial remote sensing satellite system based on spacecraft DIY is designed and its application prospect is analyzed.

Local Path Planning Method of the Self-propelled Model Based on Reinforcement Learning in Complex Conditions

Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model＇s collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.

General Elements of the ICAO-International Civil Aviation Organization Activities

The International Civil Aviation Organization （ICAO） is a specialized agency of the United Nations. Functionally, it has emerged as the organizational necessity of both the universal complex structure and the importance of its overall activity. It was created on the basis of Article 57 of the United Nations Charter, stipulating that the specialized UN agencies are autonomous international organizations. They enjoy their autonomy on the basis of the contract they were established by, being engaged in activities within the United Nations system. On the territories the organization member states comprise, they enjoy privileges and immunities, having the international legal capacity to carry out their activities in accordance to the Statute. The 1944 Multilateral Convention was to establish both protection and efficient development of international civil aviation. In accordance to that rights and obligations of member states were established. It is of a special importance to emphasize obligation of parties to take their parts in both co-operation and programs aimed at improvement of international transport, navigational equipment, and installations. In the globalized world of today, air traffic is an irreplaceable part of the system of communication. It enables fast and timely business contacts between the people from various continents, as well as transport of goods.

Explore innovative development of aero engine experimental platform and equipment

The experiment platform of the aeroengine badly needs to develope in the direction of the overall supporting, the database system management and the engineering practice. Experimental means such as the water, electricity and gas systems which support the operation of equipment, and multiple sets of engine components （the compressor, the turbine, the combustion chamber, the structural strength etc.） which support the experimental study of the engine also badly needs to improve in the direction of comprehensive monitoring and system integration to meet the needs of high efficient experiment and management. The experiment platform can make the experimental data and the experimental process be shared in different places in real time. Improving the collaborative ability of design and experiment, improving the automatic level of the experiment and so on all need the computer, the network and the professional and matching application system to support so as to guarantee the security, the stability and the reliability of the experiment, and reduce the risk of the experiment. This paper mainly discusses the main innovative exploration of experimental platform and equipment development about the current aeroengine.

Experimental Tests of the Operating Conditions of a Micro Gas Turbine Device

The aim of this work is to analyze the performance of a commercial micro gas turbine, focusing on the analysis of the fuel consumption and the outlet compressor and turbine temperature at various rpm, and to evaluate and compare the efficiency of the device. A test bench has been assembled with the available equipment in the laboratory of the department of mechanical and aerospace engineering in Roma. By using the software supplied by the manufacturer, the evaluation of the operating performance of the device at different speeds has been performed, obtaining all the values of interest.