Research And Development Of The Inference Engine Of Object-oriented Auto Brake Expert System

Expert system was produced in the middle of 1960's,it is an important branch of artificial intelligence science which is partial towards application. It is the concrete manifestation of artificial intelligence practicality. Its basic idea is to make computer store massive specialized knowledge of certain domain, and can simulate the process of domain expert to solve actual problem as far as possible. So the computer could solve complex question of certain domain well as the domain expert. With the maturation of expert system technology day by day, its application domain is also become more and more widespread. On the aspect of automobile,various auto expert systems of design, produce and analysis appear one after another,and acquire good effect. Auto brake system is an important composition of automobile, it influences the security of auto directly,but the characteristic of design process is complex computation and big work burden. If we apply the expert system to brake system design, it could improve the efficiency and shorten the period。But up to the present,auto brake expert system has not appear yet in China, so it will be a very meaningful topic to develop an expert system which could apply to design, compute and analyse of auto brake system.This thesis mainly introduces the theoretical study and concrete development of auto brake expert system inference engine. In order to combine the developed inference engine and the existent knowledge base well,fully use the existent knowledge,and make the inference process become high efficiency and reliability,it mainly study the knowledge expression method of expert system, the functions of each module of knowledge base and reciprocity,combine the task, work principle and inference process of inference engine, fix the I/O interface of inference engine, build partial regular group and corresponding explanative organization, and finally establish the practical and high effective inference engine of auto brake expert system. This thesis mainly attempts to study and solve the following questions: 1. Knowledge expression. The inference of expert system is based on the inference of knowledge, the knowledge expression method influences the design of inference engine at a large extent. The knowledge of knowledge base of auto brake expert system mainly uses the expression method of object-oriented, fully uses the encapsulation and inheritance of object-oriented, establishes the relevant class which aims at each performance, and composes various modules of knowledge bases. Each modular class contains private data members which is used to calculate, data calculation function members and result (image, forms, etc.) output function members. Expert system instances different class object according to different calculation demand, transfer the public function member of object, calculate and analyse the related performance. Moreover, the design concept of object-oriented brings enormous convenient for the program design.2. Development environment. In essence, auto brake expert system is a group of program. So it must operate in certain platform. Consider the universality and extensiveness of auto brake expert system, use microcomputer as the hardware platform of auto brake expert system. In the Windows operating system, use the extensive application programming software Visual C++ which is presented by Microsoft Corporation as the developing tool of brake expert system inference engine.3. I/O interface. Auto brake expert system mainly contains two major parts knowledge base and inference engine. These two parts include many modules, below each module has more options which together constitute the large and complex project list. Each module of auto brake expert system can accept the data which is input by the user, after the related internal calculation, showing the results to the user by script, form and image and many other forms. At the same time, show the parameters which the users have input, for user reference. According to the following principles of I/O interface and the function features of auto brake expert system, finally decided to use CJLibrary of Visual C++ program design which is a widespread application interface development tool, design auto brake expert system I/O interface with the style of Microsoft Outlook. Accept data input by the dialog box form, output the results by the form, and give the inference explanation by the performance curves.4. Data management. The realization of auto brake expert system inference engine needs the support of data. Data is important condition and fundamental security of auto brake expert system inference engine module which could function fully . Data management module of auto brake expert system is a module which is specialized used to store and manage data. It is equivalent to the"interchange"of calculation data. All the needed data of the calculation and analysis will storage, manage and transfer by the data management module. On the program realization, data management module is a visible structure variable, structure variables can store orderly different types of data together, these data called"element"of structure variable. All of the data of auto brake expert system is related to each element of the visible data structure. Eventually, put all the data together through the structure variable of data management and achieve the unified management goal.5. Establishment of inference engine. Inference engine of auto brake expert system is based on the existence knowledge, according to certain inference method and control strategy, uses inference principle group to reason, finally obtains the reasonableness of the program and compliance of the related performance. Based on the problem solving of knowledge inference is how to choose, use knowledge and complete the problem solving in the process of problem solving, the choice of inference method and control strategy is critical. According to the knowledge expression method of auto brake expert system and task and work principle of inference engine, selected the certainty positive inference way, on this basis, establish the evaluation rule of braking power distribution regulation, road adhesion coefficient utilization and not allowed the rear wheel earlier locking than the front wheel. And establishes inference explanations organization in the inference engine, explains the inference engine result by the performance curves form which aims at certain objective. In the specific procedures, the performance curve drawing is achieved by the function which is support by Visual C++. The practicality and high efficiency of auto brake expert system is verified through the specific auto models.