Design of Monitoring and Programming System of Turret CNC Punch in Windows Environment

Abstract This paper describes the overall structure design CNC turret punch Windows environment monitoring and programming system. System test and operation results show that the system has reached the expected design goals.
Keywords: turret type CNC punch monitoring programming Windows

Disign for Monitoring and Programming System of Turret
Type CNC Punch Press under Windows Environment

Lin Heng Han Zhihong Xie Yunlong Zhong Yuexian

Abstract In this paper, the overall structure of the monitoring and programming system of CNC turret punch press is designed under Windows. The test and running of the system prove that it has reached its design requirement.
Key Words: CNC turret punch press;monitoring;programming;Windows

1 Introduction

With the development of computer technology, Windows, as a multi-window, multi-task, new graphical window operating environment, has many advantages that DOS cannot match. It can perform parallel management tasks such as tasks, file output devices, etc., and provides powerful functions and a friendly graphical user interface (GUI). It is widely used not only as a support platform for managing transactional work, but also as an industrial engineering project. People are concerned. With industrial PCs entering the field of CNC, the development of CNC punch monitoring and programming systems is increasingly using the latest hardware and software products from PCs. With the development of CNC technology and computer technology, in the Windows environment, the use of advanced "5C" (Computer, Control, Communication, CRT, C/C++ language) technology, the development of CNC punch press monitoring and programming system has become a trend And direction.
Based on industrial PCs, adopting a multi-processor architecture and developing a punching CNC system in the Windows environment, foreign companies have started to develop and introduce corresponding products. In order to gain a place in an increasingly competitive market, we must learn from the successful experience of foreign countries, directly apply the latest results of today’s microelectronics and computer technology, and develop a high-performance punching CNC system that meets the requirements of users and has strong functions. It has three characteristics of “advancement, practicality, and commercialization” to continuously enhance its competitiveness in the market.

2 CNC punch press CNC system's overall design

The design of CNC punch press CNC system adopts an internationally popular industrial PC platform, taking into account the requirements of human-computer interaction friendly and real-time control. The system adopts the structure of the industrial PC dual CPU front and back office, and the IPC586 and the controller IPC486 constitutes, as shown in Figure 1. The host computer in the background completes functions such as management, monitoring and programming, and directly faces the user. The front-end controller completes functions such as data processing, real-time control, and status detection. The front and back ends exchange information through serial communication. The application software of the CNC system includes the application software of the upper computer and the controller, which are respectively operated in the Windows NT operating environment and the DOS operating environment, and each performs an independent function. The man-machine interaction control command of the upper computer is converted into a recognizable communication code of the control machine according to a certain communication protocol format, transmitted to the control machine through a serial communication method, the data processing is performed by the control machine, and the processing result is transmitted to the punch press. The actual machining control is performed, and the result and the real-time running status information of the punch press are also transmitted to the host computer through the serial communication and fed back to the user.


Figure 1 CNC system structure

3 Monitoring and programming system functional requirements

According to the overall design requirements and task division of the CNC system, the control and operation function requirements of the monitoring and programming system include system operation, processing file management, display management, system diagnosis, programming, system setting and management.
(1) System operation includes the following:
1) Automatic processing: Reference point setting, automatic continuous processing, automatic jump selection processing, automatic start code segment processing and single-step processing;
2) machining simulation: as above;
3) Manual control: Including continuous feed, mold selection step, mold continuous, step feed and manual speed;
4) MDI control: refers to manual program input.
(2) Processing file management refers to the input and output of processing files.
(3) Display management includes X, Y displacement display, tool display, part machining graphic display, I/O display, and machining program display.
(4) Diagnostic operations include communication error diagnosis, operation error judgment and alarm, and processing file program error judgment.
(5) NC programming includes graphic automatic programming and manual programming.
(6) System settings and management include system settings and tool management.
In the CNC system of the turret type CNC punch press, the user performs man-machine interaction control through the monitoring and programming system, and obtains the punching machine processing information. Man-machine interface is required friendly, so the operating environment of Windows is adopted.

4 Overall design of monitoring and programming system

(1) Design principles for monitoring and programming systems The design principles for monitoring and programming systems are production-oriented and user-oriented:
1) For production, the monitoring and programming system can perform all the required control, management and programming functions, control and monitoring, real-time control and multi-tasking. In the research and development of the system, the multithreading technology of Windows NT was adopted and the object-oriented design idea was introduced.
2) For the user, the user interface is friendly and easy to transplant, extend and modify. The human-machine interface is an important aspect of the user's evaluation of the system quality. The human-machine interface that is beautiful, simple, easy to understand, and easy to operate is an important aspect of system development. When the system is developed, the man-machine interface has a large workload. The software system in the control domain must receive user instructions on the one hand, and on the other hand deal with the real-time monitoring information from the controlled objects. Therefore, the reliability of the system is relatively high. The man-machine interface provides the necessary buffer for the real-time requirements of the system and the non-real-time nature of the person, ensuring the reliability and real-time performance of the system.
(2) The overall structure of the monitoring and programming system The data flow diagram of the design monitoring and programming system is shown in Fig. 2, where the manual processing, I/O processing, automatic processing, simulation processing and zero return processing in the dashed box are shown in Fig. 2. Completed by the controller, the data dictionary is classified as follows:
1) Data categories: graphics and processing data, setting data, MDI manual data, automatic and manual data;
2) File categories: NC files, GRA files (graphics and processing data files) and tool files;
3) Instruction class: input instruction, output instruction, manual control instruction, I/O check instruction, automatic control instruction and zero return control instruction;
4) Control information: manual control information, automatic control information, zero return control information and I/O check control information;
5) NC code class, etc.: Result coordinate, tool parameter, NC code, NC code segment, and I/O status.


Figure 2 Monitoring and programming system data flow diagram

The overall structure of the monitoring and programming system is divided into three parts: monitoring subsystem, programming subsystem and tool management subsystem. The programming subsystem includes graphic programming and manual programming. Manual programming can be achieved simply by calling an existing editor such as Notepad in Windows. The structure of the monitoring and programming system is shown in Figure 3. The three subsystems of monitoring, programming, and tool management each perform part of the functions of the system. They are relatively independent. Different subsystems have different properties and characteristics in terms of data structure, control algorithms, and control modes. At the same time, the entire system is also a subsystem. Organic combinations are closely linked, so there must be information exchange and coordination issues among subsystems. In the system research and design, the coupling between the various parts should be minimized to facilitate the realization of the functions of each subsystem. At the same time, clear information interfaces should be maintained between the systems to enhance the system's reconstruction and expansion capabilities. The menu structure of the graphic programming system is shown in Figure 4. The overall structure of the tool management system is shown in Figure 5.


Figure 3 Overall structure of monitoring and programming system

Figure 4 Graphical Programming System Menu Structure

Figure 5 The overall structure of the tool management system

With the development of flexible manufacturing and rapid manufacturing in today's manufacturing industry, CNC punch presses are also developing toward a variety of composite functions, which are more stable and reliable, more flexible, and adaptable to multi-category and small-batch production. There is a trend toward the establishment of a flexible manufacturing system for stamping processes. In the research and development of CNC system monitoring and programming system, this article strives to enhance the system flexibility, and regards the monitoring and programming system as an integrated whole with internal interaction, interaction, and mutual restraint. The functions of each part of the system are relatively independent. The tool management system manages and controls the tool magazine and turret, generates tool files according to the tool and turret parameters, and the graphic programming system generates NC program files based on the input graphics and processing information. Punch processing is monitored and controlled. On the other hand, the entire system is an integrated and interconnected, mutual-constrained whole. In the graphical programming, the tool file generated by the tool management system is used as the basis for the human-machine interactive tool selection; the automatic processing control is performed on the punching machine. In this case, the corresponding NC program needs to be entered, and a tool check is performed before machining to check whether the tool required for the NC program is consistent with the tool installed on the turret. Figure 6 shows the links between the various parts of the system.

Figure 6 Internal links between monitoring and programming systems

The overall control flow of the system is shown in Figure 7. After the system is turned on, after the upper machine and the control machine and the punch press are online, punch monitoring can be performed, and online programming and tool management can be performed at the same time; offline programming and tool management can also be performed separately.

Figure 7 overall system control process

As mentioned above, this system is divided into subsystems for monitoring, programming, and tool management. In the research and development process of each subsystem, the author introduced an object-oriented design concept and adopted the popular Windows NT technology to solve some core issues. problem.
(3) Technical solutions for monitoring and programming system development In the development of monitoring and programming systems, the author chose the Microsft Windows NT 4.0 operating system, and the development platform selected Microsoft Visual C++ 4.0.
1) Since the monitoring and programming system is a system of industrial control, the security of the operating system is very important. Windows NT fully utilizes the security features of the Intel 80386 chip protection model. Operating system modules run at different levels of authority and cannot interfere with each other. Each process also runs in a completely independent virtual machine (VMM). And other processes cannot intervene. Windows 95 and Windows NT have many similarities, but the goal of Windows 95 design is to configure the operating system for PC mainstream systems, mainly for the popularity, and Windows NT is aimed at high-tech, high-performance, and its complete performance monitoring and The event login service makes it more manageable and more secure, stable, and robust than Windows 95. In the development of this system, we chose the Microsoft Windows NT 4.0 operating system which has a human-machine interface that is friendly to the Windows 95 operating system and has a very strong security.
2) The programming language is an object-oriented C++ language. The selected Microsoft Visual C++ 4.0 is a very versatile, popular and powerful software programming platform.

5 Conclusion

This article describes the overall design of the turret type CNC punch monitoring and programming system in the Windows environment, and describes in detail the functional requirements, design principles, overall structure and technical solutions. The system has been developed, and all-round and multi-level tests of the monitoring and programming system show that the system has basically reached the design function and performance requirements. The software and hardware integration debugging of the CNC system of the turret type CNC punch press indicates that the system runs well and reaches The desired goal. The monitoring and programming system completed in this article has a friendly interface and strong functions. It can be modified and expanded according to actual production conditions. It is used in actual production. The system is suitable for China's national conditions and has a good application prospect.