1、第 1 页 共 12 页 中文 2785字 ,1730单词 外文文献原文 Motion Controller and the Application of PMAC in AC Servo CNC System Xi CHEN1 Yanbo CHE 1 K.W.E CHENG2 1 School of Electrical Engineering & Automation, Tianjin University, Tianjin China. E-mail: 2 Department of Electrical Engineering, The Hong Kong Polytechnic U
2、niversity, Hong Kong, E-mail: eeechengpolyu.edu.hk Abstract The concept and sorts of motion controller were introduced in this paper, the features of PMAC motion controller was explained, and the make-up of the numerical control system based on MINI-PMAC, PC and AC Servo Driver was discussed in deta
3、il including hardware structure and software designing. Then a development example of experiment was shown. Servo compute and control in the CNC system are both performed by PMAC,while PC and other general interfaces act as terminals, this structure offers more flexibility and can be used in a wide
4、range of applications. I. INTRODUCTION A typical motion control system mainly consists of superior computer, motion controller, power driving device, motor, feedback detecting sensor and controlled object, as shown in Fig. 1.Motion controller is the centre of the control system and it takes the cent
5、ral logic control unit as the core, takes the sensor as the component sensitive to feedback signal and takes the motor as the controlled object. The main task of the motion controller is to perform necessary logic and mathematical operations according to signals from the sensor and the requirements
6、of control task, then provide appropriate control signals for driving device. II. CLASSIFICATION OF MOTION CONTROLLER Motion controllers can be classifed in different ways.According to the structure, motion controllers can be divided into three forms: A. Computer standard bus based Motion controller
7、 This kind of motion controller has open architecture and is independent from computer.It could combine with computer by many different bus such as ISA interface, 第 2 页 共 12 页 PCI interface, VME interface, RS232 interface and USB interface. Most of these motion controllers use DSP or microprocessor
8、chip as CPU and could perform functions including motion planning, high-speed and real-time interpolation, servo filter control, servo drive and standardized general interface to external I/O. They also provides powerful motion control software libraries such as C language motion function library, W
9、indows DLL dynamic-link library and etc.So users could develop their own application softwares on DOS or Windows and create various control systems according to their own requirements. Programmable Multiple Axes Controller PMAC produced by American Deltatau company is a representative of this kind o
10、f motion. Similar products include TRIO from British Allworld company, GT series from Googol Technology ( Shenzhen ) Ltd. and NI series from American NI company. The motion controller and PC make up a master-slave control structure: PC is responsible for managing human-computer interface and monitor
11、ing the operating state of the control system in real time, and the motion controller completes all the details of the motion control task such as producing pulse and direction signals, calculating the trace, detecting home and limit signals. The advantage of such a structure is combining PCs abilit
12、y to process information and motion controllers ability to control motion trace. CNC systems with open architecture based on motion controller are widely used in equipment automation in manufacturing industry. This paper introduces the performance characteristics of PMAC and designs a PMAC-based CNC
13、 system then gives a development example. B. Software based open motion controller Software based open motion controller provides users with a great deal of flexibility.The motion control softwares are all installed in the computer, and the hardware only provides standardized general interfaces to c
14、omputer,to servo drivers and external I/O,as computer could be installed with various sound cards, CDROM and corresponding drivers. With the support of Windows and other operating systems, users can obtain desired control functions and develop various high-performance motion control system.So this m
15、otion controller provides more choice and flexibility for the users. C. Embedded motion controller This is a motion controller in which a computer embedded and it could operate independently. This motion controller also communicate with computer through computer bus. It is a variation of the bus bas
16、ed motion controller in essence.In the application it connects to a superior computer or a control panel through field communication interface such as Industrial Ethernet, RS485, SERCOS and Profibus. In addition,embedded motion controller can be provided with floppy and hard disk drivers,even get re
17、mote diagnosis through the Internet, such as Smart-Controller from American ADEPT company, GU embedded motion control platform series products from Googol Technology( Shenzhen ) Ltd. III. HARDWARE STRUCTURE OF CNC SYSTEM 第 3 页 共 12 页 The CNC system consists of superior computer,Programmable Multiple
18、 Axes Controller MINI-PMAC,adapter plate, servo drivers and AC servo motorlt in hardware. It could perform various motion control functions by using superior and inferior softwares. Fig. 2 shows the structure of the system. MINI-PMAC, adapter plate and drivers are all assembled in a cabinet, so the
19、system could work offline. A. PMAC PMAC from Deltatau company is a multi-axes,multi-channel, open motion controller. It is based on industrial computer and could control up to 8 axes simultaneously. It uses high-performance digital signal processor DSP5600X produced by Motorola as the CPU and could
20、combine with various computers, amplifiers,motors and sensors to perform different functions. PMAC is a complete computer in its own competence. It could process stored program independently of the operating system and could define task priority, working like a realtime multitasking computer.Even if
21、 PMAC is controlled by a host computer, their communication is between two computers, rather than communication between a computer and peripheral. From the processing time and the complexity of the task switching, PMACs ability to process multiple tasks simultaneity (according to the priority) reduc
22、es the burden of the computer. There are two PMAC familis : PMAC1 and PMAC2. Each can be divided into four hardware forms PMAC-PC,PMAC-STD, PMAC-LITE, PMAC-VME according to communication bus. MINI-PMAC used here is PMAC-PC form of PMAC1 which can control two axes simultaneously. It has ISA bus or RS
23、-232/422 communication port for bus communication or serial communication. MINI-PMAC mainly contains the following interfaces: Jl (JDISP): display interface, l4 pins, used to connect a simple LCD screen to display the location and speed of shafts. J3 (JTHW): multi-way DIP switch, 26 pins, to provide
24、 8-in and 8-out general I/O in TTL level, used to expand input and output points or used as general I/O directly. J4 (JRS232): serial communication port, l0 pins, to provide serial communication interface RS232 to the host coputer. J5 (JOPTO): general digital input and output port, 34 pins, to provide 8-in and 8-out general I/O in TTL level.
