1) The traditional system development process has a long cycle. When the application requirements change, the various stages of the development process must be modified accordingly, which is costly. This is because the programs that make up the various functional units of the system are designed according to the idea of ​​structured programs. Although the degree of modularity is high, the data is not neglected by the program. Since in the structured language, almost important data is defined as global data, and global data can be accessed by any program, when the structure or attribute of the global data changes, the associated program must be corresponding. modify. 2) Limited modeling and computing power. The main data models supported by traditional database systems are hierarchies, meshes, and relationships, and relational databases require that all attributes of a relationship must be atomic. In the face of abstraction and modeling of complex data, relational databases can only establish so-called nesting. The relational data model makes relational databases difficult to correspond to entities in the objective world, so the ability to abstract and express complex data in the real world can only be extremely limited. At the same time, due to the singularity of the data structure, the calculation needs to continuously convert between the objective entity and the single data structure. From the above analysis, it can be seen that traditional system development and database management are flawed in both system-level development and database design and management, and object-oriented database system development can solve these traditional development systems. the problem we are facing. 1 Principle and implementation of object-oriented database Object-oriented technology is a methodology that studies and rules the objective world according to people's epistemological thinking of the real world. It regards everything in the real world as an "object". The objective world is seen as a lot of different things. The composition of the types of objects. Each object has its own internal state and law of motion. The interconnection and interaction between different objects constitutes a complete objective world. It mainly includes three aspects. That is, object-oriented system analysis and design methods, object-oriented database technology and object-oriented programming language. Among them, the construction and analysis of objects is the key. Object-oriented design requires corresponding database support, and the traditional database design method has certain shortcomings. Therefore, it is necessary to design a database system for object-oriented design to achieve the corresponding functions. The Object-Oriented Database Management System (OODBMS) is a system that supports both object-oriented system features and DBMS system features. In designing and implementing OODBMS, there are generally three options: 1) Modify (expand) the existing data model to match the object-oriented model and add corresponding database features. The third design method is used in this paper. According to the above principle, when designing and constructing a database, object analysis is first performed. The purpose of object analysis is to analyze the specific objects that may be used in the system, the inheritance between the objects and the relationship between the subordinates. Then it is to determine what kind of data structure to use to achieve, and finally to design a library table to achieve data storage. 2 CNC turning simulation database design 1) Object analysis in CNC turning simulation As mentioned above, the purpose of virtual CNC turning simulation is centered on “usersâ€. The design of the corresponding database must also be centered on “usersâ€, which requires the database to be open. That is, for the user's requirements, the system can redefine the database content to complete the corresponding functions. The implementation of the CNC turning simulation database is based on object analysis in the software, so before the database design. The object analysis of the system must first be performed. Numerical control turning simulation objects include environmental objects, light sources, machine objects, tool objects, workpiece objects, chip objects, numerical control system objects, tool holders, slides, worktables and other component objects. Both physical and geometric simulations target these objects to reflect their state and characteristics. In object-oriented analysis, each object is defined in an abstract form of the class. In the CNC turning simulation system, the "commonness" of each object is abstracted to form a class. The principle of class formation is that all class objects must have some commonality. Classes are divided into virtual classes and real classes. A virtual class is usually the highest class in a class object and has some of the most common features. But at the same time, its parameters are relatively small. If you construct objects according to it, you can usually not display them in the view. Therefore, the real class is often used to implement the construction of the object, but the virtual class is often the parent class of the real class, and some parameters should be defined from it. Both virtual classes and real classes can have subclasses. The difference is that real classes and their subclasses can directly construct objects. Parent and real classes can have different subclasses. The class diagram is shown in Figure 2. Figure 2 Numerical control simulation class diagram Next page Steel Pipe Cutting Machine,Electric Steel Tube Cutter,Electric Steel Pipe Cutter,Steel Pipe Parting Machine Shaoxing Sunfong Intelligent Equipment Inc. , https://www.zjsxsunfong.com
2) Independently developed a new data type, directly supporting object-oriented style.
3) Embedding database functions in an object-oriented programming language to form an OODBMS. 
Object-oriented database system in numerical control turning simulation
The purpose of the virtual CNC machining simulation system is to create a simulation platform and provide a realistic machining environment. On this platform, the operator or researcher can implement a real simulation of the CNC machining process through an interactive system. Because of this, the system should have open, modular features to facilitate different combinations of CNC systems, machine tools, and machining environments based on different needs. The traditional software system is process-oriented and the corresponding support database is built for the relationship, which makes it the following shortcomings: