Radar Data Processing Software System Design Based on COM Technology Zhongzhi Li

Transcription

1 Key Engineering Materials Online: ISSN: , Vols , pp doi: / Trans Tech Publications, Switzerland Radar Data Processing Software System Design Based on COM Technology Zhongzhi Li Chengdu University of Information Technology, China Keywords: Software engineering, Module, Mixed language programming, COM, Interface Abstract. Radar data processing software is a complex system, which has been implemented with mixed language programming using Visual Studio.Net and Visual C COM-based software architecture for radar data processing system is proposed in this paper. It provides modular design framework, and integrates modules developed with different programming language and ready-made modules. Firstly, introduce COM technology in brief, then design radar data processing software system framework, finally show the programming examples to explain how to define and refer the COM interfaces. The results show that using COM-based modular mixed language programming is an effective method to realize the radar data processing software system. Introduction The large-scale software system design usually uses the software engineering modular thought. This kind of developing method always needs the cooperation of many developers who usually use different development tools and different programming languages, and sometimes we need to integrate the ready-made modules developed by different tools. It needs mixed language programming, and COM technology is an effective way to solve the integration requirement [1-5]. Radar data processing software system is a complex system whose functions are numerous [6, 7]. Some scholars have applied software engineering method to study the system's design [8, 9]. In this paper, we proposed a radar data processing software system design framework, which uses the independent modules as far as possible and considers maintenance features such as extensibility, based on the COM technology. We use the different development tools and integrate the modules using the COM technology. COM Technology Theory Component Object Model (COM) [10, 11] specifies architecture, a binary standard, and a supporting infrastructure for building, using, and evolving component-based applications. It extends the benefits of object-oriented programming such as encapsulation, polymorphism, and software reuse to a dynamic and cross-process setting. Distributed COM (DCOM) is the distributed extension of COM. It specifies the additional infrastructure that is required to further extend the benefits to networked environments. Distributed computing is becoming the mainstream due to advances in high-speed networking and the explosive growth of the Internet. Object-oriented programming has become a dominating programming paradigm for developing reusable software. Distributed objects combine these two trends and are becoming increasingly popular. More and more software systems are built as distributed object applications and they often share a number of common goals. The main objective of this paper is to identify the main features of COM/DCOM that greatly facilitate achieving these common goals. Such features include the separation of interfaces and implementations, support for objects with multiple interfaces, language neutrality, run-time binary software reuse, location transparency, architecture for extensibility, support for indirection, approach to versioning, and varying styles of server lifetime management. By using COM/DCOM as a platform to build distributed object applications, researchers and developers can concentrate on important issues All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-20/02/16,00:11:06)

2 Key Engineering Materials Vols specific to their applications without having to devote a significant portion of their efforts to building the supporting infrastructure. Client Server Custom proxy Semi-custom marshaling Custom stub Object proxy Interface proxy Channel object RPC Protocol stack Replaceable remoting architecture Transport replacement Network Interface stub Stub manager Receiver endpoint RPC Protocol stack Fig 1. COM remoting architecture and extensibility. We use the term remoting architecture [12] to refer to the entire infrastructure that connects COM clients to out-of-process server objects. (See Fig. 1) The standard remoting architecture includes, among other things, (1) object proxies that act as the client-side representatives of server objects and connect directly to the client; (2) interface proxies that perform client-side data marshaling and are aggregated into object proxies; (3) client-side channel objects that use remote procedure calls (RPCs) to forward marshaled calls; (4) server-side endpoints that receive RPC requests; (5) server-side stub manager that dispatches calls to appropriate interface stubs; (6) interface stubs that perform server-side data marshaling and make actual calls on the objects; and (7) standard marshaler that marshals interface pointers into object references on the server side and unmarshals the object references on the client side. Note that interface proxies and stubs are application-specific and are generated by running an Interface Definition Language (IDL) compiler on application-supplied IDL files. The other objects are application-independent and are provided by COM. Fig 2. System topology.

3 2298 Advanced Materials and Computer Science Radar Data Processing Software System Radar data processing software system is a part of the radar surveillance system and their relationship is shown in Fig. 2. Radar data processing system needs to implement tasks such as data fusion, target tracking, target displaying, and so on. In radar data processing software system, we develop the data processing modules by.net and develop the upper layer software by VC Data processing modules implement tasks associated with the radar data such as data communication, target tracking, target identification, original and secondary data display, data management and replaying, radar control, and so on. The upper layer software completes the system integration. Because the system function is complex, we need to design the system with software engineering modular thought. The radar data processing software system discussed in this paper uses two development tools: Visual Studio.Net and Visual C Data processing modules are developed as dynamic link library by Visual Studio.Net, and the top layer software is developed by Visual C Except the data processing modules, there have some other modules such as electronic maps, statistical analysis module, and so on. (These modules use different development tools). Because of the difference between modules developed by different tools, the modules cannot interact directly. The COM technology is the method used for mixed language programming Other modules COM Upper layer application software COM Data processing modules Interface COM interface implementation (DLL or ActiveX) Business logic dispatching (DLL or ActiveX) Common modules Common module Common data type Kernel algorithm Preprocessing module Track processing Identification module Man-machine interaction GUI module Communication Message parsing module Communication module DB Driver Data access module Manual intervention Replay module Configuration module RS422 Signal processor DB SQL Server2000 Text Fig 3. Software system As shown in Fig. 3, we divide the software system into kernel algorithm modules, communication modules, data accessing module, common modules, man-machine interaction modules and interface modules according to the modular thought. Each module is developed as

4 Key Engineering Materials Vols dynamic link library or ActiveX, and provides the COM interface for the upper layer software. Communication modules. These modules provide the interfaces for signal processor and other modules, receiving upward data and downward commands. They also provide the original message and parsing message for other modules. Data access modules. These modules provide the interfaces for accessing the database. They can deal with the primary data, the formatted data as well as the intermediate result data. Kernel algorithm modules. These modules complete many tasks such as original data pre-processing, clutter processing, track processing (target points aggregating, track initializing, maintaining, and discarding), target recognition according to the number, range, speed of targets. Man-machine interaction modules. These modules provide GUI interfaces which show the original data (B display and PPI display) and secondary data (track display). Manual intervention provide data recording, track combining or discarding. Replay module provides historic data replay by points, tracks and objects. Configuration module provides the interface with the text, and it can record and access the parameters associated with the program. Common modules. These modules define the global data type, and then sub-modules derive it and create their own data type. Each sub-module uses their derived data and then may guarantee the independence of modules. Interface modules. These modules implement logical business process of radar data processing; they establish the relationship between other modules, and provide COM interfaces for the upper layer applications. COM Interface Implementation COM server creation in.net COM interface definition and implementation. In order to allowing COM to access the properties, methods and events, we have to define them with DispId property in the class interface and implement them in the class. The sequence of these members defined is their sequence in COM. To open COM, interfaces must be public in the class. There need a GUID feature before class name and interface name. An Example is given as follows: // COM methods definition [ComVisible(true), Guid("")] public interface IComMethod // method1 definition [DispId(1)] // COM events definition [ComVisible(true), Guid("")] [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface IComEvent // event1 definition [DispId(1)] // COM class definition [ComVisible(true), Guid(""), ClassInterface(ClassInterfaceType.None)] [ComSourceInterfacesAttribute(typeof(IComEvent))] public class ComServerDll : IComMethod

5 2300 Advanced Materials and Computer Science // Methods and events implement defined in interface Interaction between COM objects and management application. Before creating COM objects, we must register them for COM Interop. It set the value of Register for COM Interop as true. For COM objects that can be called by external objects, libraries must have a strong portfolio name. It need to use SN.EXE to generated a name key, run the command as follow sn -k ComServerDll_COM_Key.snk COM interface reference in VC++6.0 Add ATL support to project. Import component library to project. #import "xxx.tlb" named_guids, no_namespace implement events receptive object. Use IDispEventImpl template in ATL to implement event receptive object, and use SINK_ENTRY_EX micro add event processing articles in event sink mapping table. class CSinkObj : public IDispEventImpl <IDC_SRCOBJ, CSinkObj,& uuidof(myeventsinterface), &LIBID_MyComLibrary, 1, 0> public: BEGIN_SINK_MAP(CSinkObj) SINK_ENTRY_EX(IDC_SRCOBJ, uuidof(myeventsinterface), 1, myeventhandler) END_SINK_MAP() STDMETHODIMP myeventhandler( ) ; Refer interface. // initialization CoInitialize(NULL); EventReceiver *preceiver = new EventReceiver(); HRESULT hr=cocreateinstance( uuidof(comserverdll),null, LSCTX_INPROC_SERVER, uuidof(icommethod),(void**)&picm); if(succeeded(hr)) // events linking preceiver->dispeventadvise(picm); // interface reference picm->mymethod(); CoUninitialize(); Summary In this paper, we propose a modular software design framework for complex radar data processing system and use COM technology to integrate the mixed language programming modules. Based on this method, we have developed an airport scene surveillance radar data processing software system,

6 Key Engineering Materials Vols which can deal with the regular changes in software requirements and is easy to integrate the ready-made modules. Therefore, the COM-based framework is open and extensible, and it is an effective method for mixed language programming application and the ready-made modules integration. References [1] Eldrandaly and A. Khalid: A COM-based expert system for selecting the suitable map projection in ArcGIS, Expert Systems with Applications. Vol. 31 (2006), p [2] Xia Fuhua, Luo Qingming and Yin Meng: Software implementation of PACS Viewer: The use of COM technology, in: Proc SPIE Int Soc Opt Eng, SPIE, Wuhan, China (2002), p [3] Niu Shuangcheng and Xu Aiqiang: A COM-based instrument interchangeable framework and its realization approach, in: IEEE Autotestcon 2008 Proceedings, Institute of Electrical and Electronics Engineers Inc., Piscataway, NJ, United States (2008), p [4] Jiang HuiXia, Luo Jin and Meng Chen: Integrated diagnosis system of ATS based on COM technology, in: Proc. Int. Conf. Model. Simul., ICMS, World Academic Union, Liverpool, United Kingdom (2009), p [5] Zhao Xujian, Jin Peiquan and Yue Lihua: Research on the COM-based reusability of evaluating models, in: IEEE Int. Conf. Inf. Reuse Integr., IEEE IRI, Las Vegas, NV, United states (2008), p [6] Fulton Caleb, Clough Patrick, et al.: A digital array radar with a hierarchical system architecture, in: IEEE MTT S Int Microwave Symp Dig, Boston, MA, United States (2009), p [7] Wang Haihong, Wang Qi, et al.: Real-time data processing display platform of imaging laser radar, in: Proc SPIE Int Soc Opt Eng, Beijing, China (2005), p [8] Fang Qing: Modularization Design of Radar Data Processing Software, Modern electronics. (2002), p (in Chinese) [9] Yang Mingjie: Modeling and Software Design of Data Processing System of A Certain Radar, Fire Control Radar Techology, (1997), p (in Chinese) [10] Information on [11] Dale Rogerson: COM Technology Inside (Tsinghua university publishing house, Beijing 1999) [12] P. E. Chung, Y. Huang, et al.: DCOM and CORBA Side by Side, Step by Step, and Layer by Layer, in C++ Report, Vol. 10, No. 1, (1998), p ,40. (in Chinese)

7 Advanced Materials and Computer Science / Radar Data Processing Software System Design Based on COM Technology / DOI References [1] Eldrandaly and A. Khalid: A COM-based expert system for selecting the suitable map projection in ArcGIS, Expert Systems with Applications. Vol. 31 (2006), pp /j.eswa