Online monitoring system of the nc machining of research

journal of hebei university of science and technology online monitoring system of the nc machining of research shi-gang wang Chen set Ma Yulin 2 2. Harbin industrial university modern production technical data of machine tool and computer communication interface and system software.For nc machine tool into!Step transformation and quality assurance system of automatic compensation research provides the necessary technical support.

271: A numerical control technology is the essence of the implementation of data driven and software control, making qualitative changes have taken place in manufacturing in the early 1980 s, the development of modern control technology to promote the development of numerical control technology, flexible manufacturing cell (FMC) appeared on the international and the flexible manufacturing system (FMS), they were thought to is the realization of computer integrated manufacturing system (CIMS) basis and necessary stage.FMS system from the point of view of structure, including the artifact flow system, cutting tool machining system flow system, the structure of the assembly system monitoring system and other subsystem, the monitoring system is a key link in the process of quality assurance function implementation.

machining size online monitoring system mainly in the process of various size parameters, real-time detection, real-time processing, and make corresponding quality control feedback, to ensure product quality.Interrupt processing recovery also need through the monitoring and control system for acquisition and storage products in the manufacturing process of the historical data, in order to analyze the quality of the information processing.

on the basis of this system is implemented in the system, is constructed based on microcomputer strong anti-jamming capability of good real-time and multitask parallel processing 1 online monitoring system of on-line monitoring system of online monitoring system based on microcomputer contact probe sensor has the following several parts: when it is in contact with the workpiece, signal a switch;X\/Y direction linear displacement sensor and related secondary instrument (GX – type A development) of Chinese academy of sciences;Used to record the X\/Y direction coordinates, and in the form of the BCD code transfer to the computer;32 road BCD code interface board);Is used for the transmission of the size of the raster information to a computer;Fund project: the national defense pre-research project of the ninth five-year plan of having to fund (13.1.1) special communication interface (SCIC) (from design and development);According to the control computer’s instruction, drive head movement, computer and information processing center;Computer related monitoring software: used to control the operation of the machining center on the computer, it is the core of the monitoring system based on microcomputer.The structure and principles of the whole detection system, such as shown in 2 monitoring system hardware devices and the interface structure in the computer control system, in order to realize the control of the production process, to the scene of the production measured parameters according to the requirements of the various ways to computer, after processing, will result in the form of digital output, at this point, also want to convert this output into suitable for quantity of the production process control.So, in between the computer and the production process, you must set up the information transmission and transformation equipment, the connection device called the output channel W input process journal of hebei university of science and technology of this system is divided into the forward channel interface and back to the channel interface were: measured object and the system is interconnected signal input channel;In this passage is mainly related to sensor signal conditioning and conversion circuit, also known as the sensor interface channel;Trigger type probe, grating and its interface belongs to the forward channel to channel, its operation monitoring system is to control the object output channel structure principle, the structure and the control object and control the Fig. 2 is closely related to the general task structuralprindples small signal output, the function of the power control XY to ac servo drive power supply and to channel after a microcomputer interface belongs to the working principle of grating ruler and install 21.1 2.1 the principle of grating ruler on the high precision CNC machine tools, the grating as position detection device it is converting mechanical displacement or analog to digital pulse, feedback to the CNC device, to realize closed loop control.Due to the development of laser technology, grating manufacture accuracy is greatly improved, now grating precision can reach micron grade, through the subdivision circuit resolution can reach 0.1 m, even higher.

decoupling, make two completely isolated from a potential of the circuit, this does not cause different potential interference into resistance, pull-up resistors under the condition of making the light coupling circuit impassability, in a high impedance state, signal conduction through 74 ls14p integer filter circuit signal into the buffer memory formation rules, when a computer instruction in b) of the four selected a functional circuit, strobing k1, k2, k3, k4, one of the corresponding signal of the cache to cache in 245, in the computer can make the signal from the k5 control, finally complete signal output 2.3 nc machine tools and the upper control computer communication interface bed CNC device with the following equipment for data transfer and information and communication;Data input and output devices;External machine control panel;General hand pulse;Feed drive circuit and main shaft driving circuit with the development of factory automation (FA) and CIMS, nc device as FA or a hierarchy of CIMS architecture, in addition to connected to the data input and output devices, and communication with host control computer, so should also have the function of the network communication between the computer communication technology is relatively mature, computer and machining center and the communication is not easy, and most of the existing machining center is not designed for network communication.The vast majority of cases through the serial port (RS – 232 – c) cannot transfer control instruction.Therefore, to realize comprehensive communication of upper computer and machining centers, must also develop a dedicated communication interface unit.The initialization module implements various initialization parameters, such as: pulse when the amount of ~ (PULEQU), timer timer 1 and 2 of the working party broken query module in the process of detection, as a result of the probe trigger signal is random, according to the requirement of the system, when the trigger signal, should be achieved: 1) the computer can accept and identify the signal;2) after the received signal to control machine tools in the axial locking;3) read the grating ruler of transmission signal at the same time, and processed in order to achieve the above purpose, taking three works: first, capture interrupt number 0 x72 softirqs, before the signal control, with the interrupt trigger signal input port for query through the feedback signal to determine the execution direction;Second, the use of computer internal timer interrupt, due to the microcomputer system is 18.2 times per second clock interrupt (IRQ1), in which the soft interrupt call, then, the frequency of the use of it can be 18.2 times per second to activate memory-resident program, inquiry and third time background, raster display module software query manner.In order to form a closed-loop detection control system, the raster data transmission should be real-time display, and can be stored in a data file for after the completion of the test data processing and adaptive compensation control.Grating transmission of data in the form of BCD code, and by operating a counterpoint is transformed into a binary number in this module are: data storage, display, single point more and error separation.

the direction control module.Set according to the actual situation of each axis direction of feed, all directions corresponding to different parameters set port operation timely order relation of feed control module.Reference speed potentiometer control mode and working principle, to design the complete control of feed speed work way of sub function (such as control of feed speed increase SETFEEDINCRECE) temporal relations including fast feed control, micro feed control and feed rate control.

spindle speed adjustment module by setting the spindle speed control works of sub function (such as control spindle speed increase SETROTATINCREASE) temporal relationship between giant automatic detection module to complete the work.For detecting path based on optimizing the control of interpolation, the steps don’t throw and it does not increase to achieve as soon as possible under the premise of feed speed interpolation algorithm for trajectory planning of real-time control of motor speed control, and take into account the location of the interpolation output 4 conclusions in this paper, the numerical control processing precision and detection efficiency of on-line monitoring technology has carried on the comprehensive experimental study, draw lessons from the domestic and foreign advanced experience monitoring, the monitoring experimental system is constructed based on microcomputer, made a special communication interface card;Using VC + + compiled a monitoring system based on WINDOWS software, which can realize multitask parallel processing;USES the digital pulse technology designed and developed to monitor prior to and after the channel control software.Through many times of experiment system operation, the measured a large amount of data, experimental data analysis results show that the system actual use effect is good, the desired research target of