NC System Research Articles

A New Kind of Numerical Control Method

A new kind of numerical control system is presented in this paper. The main movement of the numerical control system is driven by the traditional power, such as hand wheel or hydraulic power, the movement is detected by an grating detector, or other detect devices and the displacement of the main movement is input to a computer simultaneously. finally the computer drives the other axis to move immediately, according to the preset program or rule. In this way, the NC system, for example, NC machining tool, can realize any kind of complex and powerful cutting or manufacturing at higher maching speed than other machines. With the higher power and speed servomotor or servo system expansiving, this system will fulfill working task with higher productivity and lower cost.

Machining Posture and Movement Coupling of the 6-Axis Machining Stewart Robot

The Stewart machining robot adopts a closed ring structure; the shaft was connected with a number of spatial links. In the coordinate system fixed on the cutter, the coordinates of the hinges joining control links and shaft can be determined. And the posture of the tool can be determined as well. Corresponding to every posture of machining, the position of shaft can made the lengths of the two Control axes equal. So that if one of the controlling ends of NC system controls two axes simultaneously, a 5 coordinate system can realize the function of the 6- coordinate system.

Development of NC System of the 3-PUU Parallel Machine Tool Based on PMAC

In this paper, a PUU parallel machine tool with three translational degrees of freedom (DOF) is designed which is usually used in the complex grain machining of the solid rocket engine.， and its numerical control system is described in detail. The so-called “PC+PMAC” is used as the hardware platform, and Windows as the software one, the parallel machine tool NC system is built. The features, such as multi-axis motion control and fast real time communication of PMAC, software resources and efficient data processing of PC are utilized such that Man Machine Interface, position servo control, real time measurement of cutter configuration and closed loop control of the parallel machine tool are realized.

Research and Development on the Open PMAC-Based CNC System Software

Based on PMAC open CNC system, which features an open secondary development of space left to the designer. This topic has developed a set of application and secondary development of the NC system experimental platform, that is, IPC (industrial computer) machine + PMAC structure of open CNC system. This issue focuses on the overall structure of the numerical control system software design and the function module design and development process.

Study on Key Technologies of Practical DNC System

Aim at the communication problems of computer and NC machine tool, a practical DNC system is developed in this paper. A three-layer control structure mode – which is composed by the unit layer, DNC computer workstation layer and NC system equipment layer – is presented. Based on its good real-time capability and high reliability, CAN field-bus is introduced into the DNC communication system construction, the network topology is constructed and related hardware is chosen properly. Using VC++6.0 as development tool, and assisted with special compiling tools LEX&YACC, 3D standard graphic library OpenGL and database Microsoft Access, and based on the multi-task and multi-thread technologies, the software of the system is developed. The system has the characteristics of reliable operation, simple structure and high real-time capability, can improve the efficiency of NC machining process obviously, and has a certain application prospect in the middle and small scale manufacturing enterprises of our country.

Research on the Plan for NC System Based on STEP-NC

To resolve the problems aroused by G code in manufacturing industry, a plan for NC system based on STEP-NC is proposed. The whole system is designed into two parts: system software and system architecture. With modularized design thinking, the control software includes five modules: interpreting module, man-machine interface, task coordinator, axis group module and axis module. For the system architecture, an open architecture is used which adopts different products from different manufacturers, being connected together by softSERCANS bus. By a machining test, the expected machining features are realized, proving that the NC system designed is reliable.

Design and Research of Embedded Internal Grinding NC System Based on μC/OS-II

According to the requirement for high-precision and processing features of the internal grinding, the hardware and software of an internal grinding NC system based on embedded system were presented. The classification and implementation of several key system tasks controlled by real-time operating system uc/os-ii were given, and the control process of the machine switch by soft PLC technology was elaborated on in the system. According to the real-time requirements of internal grinding NC system, the tasks of the system were prioritized reasonably, and some methods for enhancing the capability of real-time and improving the accuracy of the system were presented with software technology.

NC Polishing of a Press Roll with an Arc Surface of an Ultra-Large Radius

The paper discusses the NC polishing and NC repairing of the arc surface with an ultra-large radius of the paper machine’s press roll. It is very difficult to polish and repair press rolls whose radius is up to several thousands of meters because it is quite beyond the range which a NC system permits. The special NC reconstruction of a machine tool and its principle and method were elaborated. In an example the accuracy of parameters conversion was calculated and related formulas were derived, and also the methods of eliminating errors and the measures to compensate errors were discussed. In view of the abrasion of the grinding (or polishing) wheel, the measure for instantaneous automatic compensation was discussed.

Analysis Method of Motion Accuracy Using NC System with Synchronized Measurement of Tool-Tip Position

This paper describes a method of measuring and analyzing the motion accuracy of NC machine tools. A practical method of measuring the motion accuracy is required for the achievement of high precision machining. The motion accuracy of NC machine tools becomes an issue, as motion error emerges while a continuous path control is applied. Error is caused by several factors. In order to determine the effects of each cause, it is necessary to measure the differences among reference positions, feedback positions, and tool tip positions. Thus, a system of measurement that achieves synchronized acquisition of each of the aforementioned positions has been developed. The system is composed of the NC system, which can manage the reference position and the feedback position, and an additional sensor data acquisition system, which receives the tool tip position. A method of analyzing the acquired data to determine the motion accuracy is also proposed. Experimental results show the effectiveness of the proposed method.

NC flame pipe cutting machine tool based on open architecture CNC system

Based on the analysis of the principle and flame movement of a pipe cutting machine tool, a retrofit NC flame pipe cutting machine tool (NFPCM) that can meet the demands of cutting various pipes is proposed. The paper deals with the design and implementation of an open architecture CNC system for the NFPCM, many of whose aspects are similar to milling machines; however, different from their machining processes and control strategies. The paper emphasizes on the NC system structure and the method for directly creating the NC file according to the cutting type and parameters. Further, the paper develops the program and sets up the open and module NC system.

Bounds on the parameter of noncommutativity from supernova SN1987A

We consider supernova SN1987A to find bounds on the parameter of noncommutativity, {theta}{sub {mu}}{sub {nu}}. The right-handed neutrino in the noncommutative standard model (NCSM) can directly couple to the photon and the Z-gauge boson. Therefore the observed flux of neutrinos from SN1987A can constrain the strength of the new couplings in the NCSM. We obtain two bounds on the NC-parameter, {lambda}{sub NC}=1/{radical}(|){theta}|, with respect to escaping or trapping of the right-handed neutrinos inside the supernova which are {lambda}{sub NC} > or approx. 3.7 TeV or {lambda}{sub NC} or approx. 3.7 TeV is more stringent than the other bounds obtained from LEP and LHC considerations. Furthermore, since NC calculations are perturbative and are correct only up to the energy scale of the NC system < or approx. {lambda}{sub NC}, then thesemore » bounds (which are obtained from the energy scale and considerably less than the energy scale of LEP and LHC) are more reliable.« less

The Forming Theory and Computer Simulation of the Rotary Cutting Tools with Helical Teeth and Complex Surfaces

This paper researched the forming theory of the cutting tools with helical teeth and complex surfaces. Deduced the nonlinear equations of the movement of NC system to generate such tools, presented the way to find the solution of the equations, calculated the cross section graphics of the teeth profile and computer simulation of NC machining.

Application of LabVIEW in Flame Cutter NC System

In this paper, a system was introduced, which bases on Flame Cutter NC System and software platform of LabVIEW which the USA NI company developed. Composing of NC machine, partition of modules and assignments, functions confirming, data processing of machining and control, structure of software by the numbers and realization method of two CPUs. The system makes use of multitasking of LabVIEW to make the programmer realize easily the task, which is difficulty to acquire in in tradition programme. It is a kind of comparatively convenient and swift thinking to realize system interface and multitasking by the platform of LabVIEW.

The Reconfigurable Embedded NC System Based on FPGA

The hardware and software design method of reconfigurable embedded NC system which makes use of FPGA’s abundant logic resources and programmable characteristics is presented. It introduces the scheme of a embedded NC system which has regarded FPGA as the control center. It mainly represents the thought of reconfigurable design, the speed control of stepping motor, and the communication of FPGA and PC. As a result, this system has fast response and strong reconfiguration ability. It can reduce the number of peripheral interface devices and result in costreduction.

Code Translator of STEP-NC Based on ISO14649

For the application of STEP-NC in NC system, an STEP-NC code translator is exploited. Firstly, summarizes the limitation of conventional standard ISO6983 and the superiority of STEP-NC. After an analysis on two different generating methods of STEP-NC program, introduces the exploited STEP-NC code translator based on ISO14649. According to inner logical relation, the code translator is composed by six functional modules, an operating principle chart is presented, function and realizing method of every module is disserted on. At last, exampled with a program which includes planar face, pocket, slot, Bezier surface and replicate feature of round hole, planning the whole toolpath of the program using extracted information about workingstep, feature and operation by the exploited STEP-NC code translator. A cutting simulation is made to the toolpath and the workpiece model. The result proves the feasibility of the STEP-NC code translator.

Basic Experimental Research on the NC-Contour Evolution Ultrasonic Assisted Grinding Ceramic Blade Surface

Ultrasonic machining is a practical process for advanced ceramic machining. Usually, ceramics with complex surfaces are machined with two common ultrasonic assisted contour machining methods, which may be classified as surface/point contact machining mode. While these methods are not suitable to machine some complex surfaces such as blade surface, so an ultrasonic assisted contour machining method using a simple shaped diamond grinding wheel to machine ceramic blade surface is presented, which is named as Numerical Control-Contour Evolution Ultrasonic Assisted Grinding (NC-CEUAG) method. In the NC-CEUAG process, the contour evolution motion of the grinding wheel is controlled by the NC system and the blade surface is the enveloping surface formed by the grinding wheel’ cutting edges when they cut into the ceramic specimen. In this paper, the relative motion between the grinding wheel and the specimen in the process of NC-CEUAG ceramic blade surface is analyzed. The mathematical models of ruled surfaces are constructed. The ceramic blades with ruled surface are machined with selected machining parameters on the retrofitting NC-CEUAG machine tool.

Information service of the resource node in a manufacturing grid environment

Manufacturing resource information management is the precondition for manufacturing grid (MG), which provides the foundation for harmonious sharing of the distributed manufacturing resources. Research on the information service of the resource node in an MG environment will build up a solid theoretical and technological fundament to realize a manufacturing grid platform. This paper mainly focuses on resource registration, expression, and encapsulation in the MG environment. Taking the embedded NC system as an example, this article offers expression of the manufacturing resource with XML, which avoids the misunderstanding of different formats. This article also realizes the resource encapsulation and deployment, as well as information publishing and issuing with the help of Java supporting tools.

Backlash Compensation of Reduction Gears by Twin Motor Cooperative Control (1st Report)

Backlash of reduction gear produces troubles in case of positioning of robots and NC machine tools. It sometimes causes deterioration of positioning accuracy and self-excited vibration. To overcome such troubles special reducers, for example the harmonic drive or RV drive. But such reducers have special structure, so the cost of the reducer becomes expensive in robot or NC system. In this study, a new control method, named twin motor system is studied, that is two servo motors are controlled cooperatively and compensate the backlash of reduction gear.In this report, a basic simulation model of backlash model is proposed and conditions of twin motor pinion and output gear is analyzed. Experimental results of servo stiffness improvement and 1 pulse positioning accuracy are reported.

Control System Configuration for Grinding Machine with Two Moving Axes and One Circumrotating Axis Ganged Function

By applying NC system with three axes ganged function to M1432 universal cylindrical grinding machine, a NC grinding machine with two moving axes and one circumrotating axis ganged function is designed and developed. Besides two moving axes ganged function, this machine has a special function of driving the form wheel dresser to circumrotate around the Y axis. Ordinary grinding machine with two axes ganged function can’t machine complicated parts such as seaming roll with steep gradient groove. But a grinding machine with this special unction can do this by precisely dressing the form wheel with various aspheric curves. With the set-in PLC function of NUM1020 NC system and the correlative parameters to be respectively setup, the new machine can be used to machine some complicated parts such as seaming roll. The system receives machining process codes which is pretreated by computer firstly and dresses the form wheel in DNC mode, then machines parts with the form wheel later.

1510 マシニングセンタの直線補間運動におけるコーナ部誤差の推定(S77 工作機械,S77 工作機械)

In this study, the authors develop a convenient method to estimate the corner errors caused by the linear interpolation motion of a machining center. Only a few measurements to simple motion trajectory are necessary for identifying the parameter values due to the acceleration and deceleration control rule in the NC system. The effectiveness of the method has been sufficiently verified from experiment results.