The Design Of Simulation Software Of The Large Carrier Flight Simulation System

XX is a large-scale cargo airplane, the simulation of the aerodynamic characteristics and the passenger cabin apparatus are both more complicated than other planes. During the process of the software design, if still use the structurization design method, it will be inevitably confuse, the coupling between the procedures is close and the expansibility is bad. Countering this question, this text has explained the method that use the object-oriented design method to carry on demand analysis, preliminary design and design in detail to the simulation software of XX large-scale cargo airplane,In order to describe clearly and accurately the design method of the simulation software of XX large-scale cargo airplane, this text mainly explains through four following respects:1. The superiority of the object-oriented design method to simulationAdopts the object-oriented design method, the software developer can set up simulation model with their familiar target concept on their own specialty, the modeling view is identical with the mode of thinking on knowing made up of the plane, thus strengthen the ocular and intelligible of simulation modeling. Meanwhile, the kind and succession in the object-oriented design method offers a multi-level abstract mechanism that from the target, kind, kind library until the special-purpose system framework, and can supports the setting-up of the level model of the complicated system on many kinds of levels.The object-oriented design method apply on the development of the simulation software, which makes the targets in software correspondence to the composition of the plane one-to-one, so the main task of modeling is to construct one kind of models of the software according to the composition of the plane, and the developer can transform one kind of models into new kinds of models appropriate modification and association by oneself according to the needs of question. This method not only can help the developer to construct target's model by the predefined method, but also favorable for them to sets up flexible kinds of models.2. The demand analysis of the simulation software of the flightAfter adopted the object-oriented design method, the method of demand analysis is different from the structure analysis, it is the major problem to set up the target model during the demand analysis of the simulation software. Through considering synthetically the static structure, behavioral characteristic and information transmission of XX cargo airplane, and according to the request of simulation task, the simulation software can be divided into three main target models. These three main target models are"simulation model of the plane system","simulation model of the systematic environment"and"simulation model of the airborne apparatus". The"simulation model of the plane system"carry on simulation on air dynamics, charges the six degree of freedom non-linear the whole quantity sport equation; the"simulation model of the systematic environment"simulate the influence of the disturbed air and wind power to plane in the flight course; The"simulation model of the airborne apparatus"is responsible for the emulation of the environment of aircraft cockpit, finishes the electric apparatus of boat, handles the emulation of using the characteristic and function characteristic of airborne apparatus such as apparatus, engine apparatus.3. The preliminary design of the simulation softwareIn the preliminary design process, finished the designs of system structure of the software and the kind models according to relevant design principles, and distributed each function of requirement analysis to each part of the software, change into the realizes scheme which according with the quality requirement. The system structure of the simulation software adopted three layers structure, that is: the administration layer, the entity layer and the data layer. The administration layer is responsible for realizing management and control to simulation overall. The entity layer simulation is the main execution part; the most procedure module of the simulation software run in this layer, the data layer plays the database function, preserve the data of various constituents in the simulation software. The software structure after divided layer is easy to understand, more rational and normal.In the simulation software of the XX large-scale cargo airplane, kind is a basic component, so in software design, the most difficult part is to resolve systems into target assemble. Because there are so many factors should consider: encapsulation, granularity, dependence, flexibility, performance, evolving, replying and so on. They are all influencing the resolving of system, and these factors usually conflict each other.In the process of design the kind, the flight simulation be divided into several kind according to the corresponding design, watch from the function realized, can they can be divided into modeling target kind, manage and control kind, user interface kind. The modeling target kind include"aerodynamic characteristics","qualitative characteristics","motion equation","auxiliary power unit","fuel system","landing chassis","control system","automatic flight","engine","electrical appliance","flight management","air data", "airborne electronic instrument landing","microwave landing system","GPS navigation","compass navigation","DME navigation","inertial guidance","TACAN navigation","VOR navigation".The manage and control kind includes"algorithm management","control management","model management". The user interface kind includes"scene data interface","dynamic data interface","teacher controller dynamic data interface"and"course pass way".4. Detailed design of the simulation softwareThe main task of the detailed design is makes sure the algorithm and attribute in detail for each kind in the software. In addition, the interface and storehouse design are finished. The simulation software needs a large number of data while operating, so the management of the data seems particularly important, the simulation database is constructed with by data table system, data pool, public variable district and symbol dictionary. And the data in the database can be divided into three major kinds functionally: First is initial data of plane; Second is common data such as trial flight data and wind section that is used in measuring and assessing in real time; Third is the real-time simulation result data, include the result produced by the every system and the a large number of chain data.Though the simulation software is run independently, but it carry on with the information transmission system, the vision simulation subsystem, sensation of movement simulation subsystem, and teacher's control cabinet, so the design of the outside interface is essential, the interface of outside mainly finishes each software and divides the data transmission between the systems, enable every software subsystem to unify, finish the simulation task coordinating.Except the outside interface, there is data transmission between the inner sub-modules, and mainly in the charge by the internal interface. The realization of the internal interface has adopted two ways: according to the not same layers, the middle kind is adopted. And according to the same layers, the common function is adopted.During the process of design the simulation software to the XX large-scale cargo airplane, the extendibility, reusablebility and maintainability is consider enough. And the software has met the requirement of the XX large-scale cargo airplane simulation, the software is easy to revise, it is reliable to be flexible, the system still runs well after the customer changes the demand many times. And the design of some module has met the requirement of commonability. The fact proves, the good software system structure can establish the theoretical foundation for developing the common emulation storehouse, have offered strong technical support for developing the large-scale complicated artificial system and mutual artificial system.