微型雕刻機(jī)總體及數(shù)控系統(tǒng)選用設(shè)計(jì),微型雕刻機(jī)總體及數(shù)控系統(tǒng)選用設(shè)計(jì),微型,雕刻,總體,整體,數(shù)控系統(tǒng),選用,設(shè)計(jì) Research of PMAC-based open NC system for Engraving and milling machine Pan LianYan WenPan yu College of Information Science and Engineering Wuhan University of Science and Technology Wuhan, China Li KeLu WeiXu Hui College of Information Science and Engineering Wuhan University of Science and Technology Wuhan, China Abstract-To solve traditional NC system for Engraving and milling machine problem of high cost or difficult in change parts. The paper introduces an open architecture numerical control of motion and PLC, base on high performance PMAC Motion engraving and milling machine tool system base on IPC and PMAC motion control, across to chose suit Servo drive ,Servo Control Card , add to secondarily developed human machine interface, compose open NC system. the system Achieve high performance high speed high Accuracy, and all Interpolation movement ,can intend of machine abroad. Keywords-PMAC; Numerical control system; Engraving and milling machine; Interpolation I. INTRODUCTION Against the current of traditional CNC engraving and milling machine manufacturing high costs, exist in the high single function, replacement parts problems, low precision, so that can not meet the needs of industrial development issues, this paper presents the use by the PC + PMAC posed by the open architecture CNC system. The use of PMAC, high-speed computing power and features of the open structure of the system to achieve the high performance, high-speed, high precision and accurate completion of motor control ,to achieve a variety of interpolation operation, and simultaneously reduce costs. II. OPEN CNC SYSTEM This article is based on PMAC engraving and milling machine open CNC system research, is mainly directed against a set based on the IPC + PMAC motion control card open CNC engraving and milling machine systems research, give full play to the advantages of open CNC system in order to reduce machine costs and maintenance costs. Application- specific PMAC motion control algorithm to solve the process of engraving and milling complex parts of the track, while VB application software development man-machine interface, human-computer interaction to achieve the rapid real-time accuracy. Currently*traditional CNC engraving and milling machine tools exist many problems, professional machine tool manufacturing take high costs, the hardware-specific software is not easy stretch, the hardware is difficult to adapt to competing demands, difficulties in the second opening, special system development is not easy, network costs are high, special-purpose language is difficult transplantation, interface- specific. This topic provides an open-architecture CNC engraving and milling machine system, the program can be achieved by the system scalability, maintainability, easy to open the second, through standardized interfaces and languages completely solve the problems of traditional CNC machine tools to reduce the cost of production of machine tools . In general, the benefits of open CNC include the following: 1) The user can be required to receive programming 3U parts. 2) It can be connected with many different operating systems (Windows, windows NT, Unix, OS2, etc.). 3) Do not have to abandon the current hardware platform, we can upgrade controller. 4) The controller hardware provision and maintenance, there is no single supplier boundaries, reducing the system and maintenance costs. 5) The open technology control suitable changes in the market and easily be changed to update the latest technological reserves. 6) a common programming language that can be used to develop a different interface. 7) to low-cost gain to higher features. The project uses a multi-axis motion controller PMAC as NC modules, has developed a basic set of full-featured general-purpose numerical control system, PMAC provides the machine tool main function, the robot characteristics, timing and general automated detection performance, can handle motion control, logic control, resource management and host interactive work. Compared with traditional high-cost CNC engraving and milling machine, software development is difficult, maintenance complex, the CNC engraving and milling machine to control the realization of intelligent, operating system, universal, traditional markets, the impact of specific numerical control. At the same time this system take low cost, short development cycle, running speed, high control This work is supported by Nature Science Foundation of Hubei Province ( 2009CDB270). 978-1-4244-7739-5/10/$26.00 2010 IEEE precision, can be faster, and more to complete a variety of processing tasks. III. CNC ENGRAVING AND MILLING MACHINES HARDWARE DESIGN NC system is a PC-platform under the Windows interface, a new type of numerical control system, which through the PMAC multi-function numerical control card to convert the signal to complete the signal input and output. Semi-closed loop control part of the control method shown in Figure 1: Fig.1 Semi-closed loop control part of the control method Its control is composed mainly of five parts: servo encoder feedback, the computer, the main circuit control, volume control switch as shown in Figure 2: Fig. 2 volume control switch This paper described an open-architecture CNC engraving and milling machine spindle, and by the frequency conversion three-phase asynchronous motors, AC servo unit and AC servo motor, cooling pump, PLC, rail, roller screw, measuring devices, I / O interfaces, travel limit switch so on. NC device uses a IPC + PMAC motion control card 10 software. The device uses an advanced open architecture, built-in embedded industrial PC, through real-time control features packaged into a complete industrial-grade intelligent motion control platform. A 17-inch bright TFT LCD screen. Frequency spindle uses a Panasonic inverter. AC servo system uses the Sanyo AC servo drives, PMAC card chose PMAC2A-PC104, mechanical parts using a ball screw drive, servo motor AC servo unit and formed a close-loop speed control system. Installed in the working platform grating ruler moving away from direct measurement of the mechanical parts, and other components to form a closed loop position control system; through the installation of the AC servo motor shaft to serve as an incremental encoder position sensor for the indirect measurement of the mechanical parts mobile distance with other components to form a position of semi-closed loop control system. IV. PMAC MOTION CONTROL CARD PMACs full name is the Programmable Multi-Axis Controller. It is Deltu Tau Data System Inc. produced a series of broad support for a large number of programmable multi- axis motion control card. PMAC as a high-performance servo motion controller, digital signal processor (DSP), and a flexible high-level language to control up to eight axes at the same time exercise. PMAC to an unprecedented multi-axis controller provides cost-effective, using Motorolas DSP56 series digital chip as the CPU, to handle all eight axes calculations. Stored in its internal procedures in making a separate operation, the implementation of sports programs, PLC program, to servo loop update. Enabling real-time multi-tasking, which makes it a task switch in processing time and greatly reduces the host and programmer of the burden of the whole control system can improve the speed and control accuracy. The numerical control system selection model is PMAC2A- PC/104, it is standard 40MHZ DSP master clock, optional 60/80MHZ, PC104 bus and stored with flashmemory campaign procedures, etc.; standard 4-channel PWM digital output, variable for the pulse + dir digital signal or the DAC 10V analog output with a resolution of 12 bits; standard RS232 serial port, optional USB or Ethernet communication; each axis is equipped with dedicated LIMIT (limit), HOME (back to zero) , FAULT (servo alarm), USER (user-defined) and AENA (servo enable) input and output signals. V. CNC ENGRAVING AND MILLING MACHINE MAN-MACHINE INTERFACE DESIGN The numerical control system software using VB and the Delta Tau provided pmac.dll dynamic link library preparation. Through the Delta Tau PComm32PRO communication driver is a Windows 98/ME/2000 and XP environment, the establishment of PMAC application development tool, you can set up and use more than 400 performance function. This program is designed to be powerful, fast, and portable use function 8. PComm32PRO the PMAC can be common in all devices and communications. PComm32 contains a total of more than 250 small functions. The numerical control system software to achieve the following functional modules: 1). Mechanical parameter setting module. Mechanical parameters typically include pulse-equivalent, the pivot point moving speed, the pros and cons of various axle limits to software such as stroke. Request this software system provides a dialog to the user modify the mechanical parameter values, when the host and PMAC to establish communications, these mechanical parameters can be automatically assigned to the corresponding PMAC variable, set the controller so as to achieve the purpose of the system constant value. Shown in Figure3 below: Fig. 3 Machine parameter setting module PMAC values obtained are generally pulse volume, by calculating the amount of displacement roller screw and encoder speed and PMAC in the internal settings to turn it into mm, mm / s units. (As a motor as an example) Location coordinates to obtain a machine tool motor program: PmacGetResponseA (DeviceNumber, response, 255, # 1 p) Pulse is converted to equivalent amount of displacement process: Format (Val (response) / 1638.4, #.#) 2). Communication with the PMAC card function module. The module is used PMAC.DLL dynamic link library provided by the OpenPmacDevice () function implementation PMAC-axis control card and the host of the serial communication capabilities.Program command: OpenPmacDevice (DeviceNumber) ClosePmacDevice (DeviceNumber) . 3). PMAC card command-line module. The module will provide users with a text box to receive the user commands issued by the PMAC to control the PMAC card. Order entry process: PmacGetResponseA (DeviceNumber, response, 255, command), command-feedback can be displayed to another text box, shown in Figure 4. Fig. 4 Command Line Module 4). Jog motor module. The module is used to control the motor X, Y, Z axis movement and stop the forward and reverse movement, you can also specify the location and distance of motor displacement shown in Figure 5. Forward movement command procedures: PmacGetResponseA (DeviceNumber, response, 255, # + Str (n) + j + p) Campaign Negative command procedures: PmacGetResponseA (DeviceNumber, response, 255, # + Str (n) + j-p). Fig. 5 motor jog Module 5). Motor back to the zero module. The module can be achieved automatically return to the work of the origin of X- axis, Y-axis automatically return to the work of the origin, Z- axis automatic return to the work of the origin of. PMAC cards have a set of hardware to capture the origin of the internal switch mechanism that can automatically return to the origin of all axes motors automatically. When the PMAC motion control card built-in hardware capture mechanism was found when the action switches back to the origin, it will capture the origin and precise location, and in accordance with a certain trajectory back to that location. The system adopts the PLC controls back to zero, so that control the direction of a positive return to zero. 6). Tool library information. The module can input and display tool compensation information. Cutter Compensation can be used to enter information into the tool library, to facilitate adjustment to compensate for Automatic Tool Changer. 7). Monitoring module. The module is able to complete the following two functions: First, update the interface information, including X, Y, Z axis program coordinate, X, Y, Z coordinates mechanical, X, Y, Z axis speed; 2 is to monitor the safety of all I go information, including machine status, alarm system, restrictions. When a security failure, the module can be automatically recorded in the following types of security failure, time and other information, and will be credited to the kinds of text documents available to the manipulator, shown in Figure 6. Fig. 6 Monitoring Module 8). Download the implementation of sports program modules. The module can be the standard G-code files into a blank card can be identified PMAC axis motion program or PLC programs to read and can be downloaded to PMAC axis blank card. Download PmacDownloadA (DeviceNumber 0,0,0, CommonDialog1.FileName, True, True, 1, True) 9). Sports program execution module. The module can perform downloaded to PMAC axis motion control card processing center. To sum up, the software can be drawn function of the system block diagram, shown in Figure7: VI. CONCLUSION This article describes the PMAC motion control card based on + IPC CNC engraving and milling machine, tells the CNC system hardware selection, as well as in human-machine interface developed under VB. At present the device has been used in practice can be long-term stability of operation, to meet production or teaching requirements. PMAC motion control card using the open numerical control system can improve the scalability and portability, hardware replacement and software upgrades are very convenient, greatly reducing development and production costs, easy maintenance, for system expansion or improvements are very significant Fig. 7 Movement program execution module in the interface. Work, the need to set up a variety of mechanical parameters, the system will establish communication with the PMAC, this time process monitoring module automatically start and initialize. Next, the user may choose to conduct electrical point of action, or enter the PMAC command, or the axis back to zero, and download the exercise program, while processing of shapes displayed . REFERENCES 1 Lesotho court. PMAC-based open-architecture CNC System J. Manufacturing Automation, 2002,24 (9) :34-36. 2 Ren Yutian, et al. Machine computer numerical control technology M. Beijing: Beijing University of Technology Press, 1996 3 Schustar GMxiaohuan Li.Katasaggelos AK Shape error concealment using Hermite splines.Image Processing,IEEE Transactions.2004 ,6,13,808-820. 4 Liu Juan. PMAC-based open-architecture CNC system development J. Modular Machine Tool & Automatic Manufacturing Technique, 2004 (10) :84-86