Computer Numerical Control System Research Articles

Design of Servo System Intelligent Control Chip Based on FPGA

According to the required functions of speed control and position control in Computer Numerical Control (CNC) system, the hardware control modules of speed and position are designed based on Field Programmable Gates Array (FPGA) of CYCLONE II family. The software hardening technology is used for speed control and position control. The servo intelligent control chip consists of reset unit, frequency division unit, speed processing unit, subdivision unit, phase discrimination unit, counter unit, compare unit, etc. Through analysis of waveform simulation, the correctness of design and the enhancement of transportability and reliability are achieved.

A control strategy with motion smoothness and machining precision for multi-axis coordinated motion CNC machine tools

The advanced manufacture technology requires that multi-axis coordinated motion computer numerical control (CNC) machine tools have the capability of high smoothness and high precision. At present, the study of the motion smoothness mainly concentrates on the acceleration and deceleration control method and the look-ahead process of velocity planning in the interpolation stage. The control strategy of the contouring error mainly focuses on tracking error control, cross-coupling control, and optimal control. In order to improve the motion smoothness and contouring precision for multi-axis high-speed CNC machine tools, a multi-axis modified generalized predictive control approach was presented in this paper. In the control strategy, the estimation models of tracking error, contouring error, velocity error, and acceleration error were structured separately. A new improved quadratic performance index was proposed to guarantee the minimum of these errors. Generalize predictive control was also introduced, a multi-axis generalized predictive control model was deduced for motion smoothness and machining precision for multi-axis coordinated motion CNC system, and an approved multi-axis generalized predictive controller based on the model was designed in this paper. The proposed predicted control approach was evaluated by simulation and experiment of circular, noncircular, and space line trajectories, respectively. These simulative and experimental results demonstrated that the proposed control strategy can significantly improve the motion smoothness and contouring precision. Therefore, the new position control method can be used for the servo control system of multi-axis coordinated motion CNC system, which increases motion smoothness and machining precision of CNC machine tools.

Developing and Research on Motion Controller Based on CPLD and MCU

Open Computer Numerical Control system (Open CNC) based on PC and the Windows operating system has been a major developing direction and a research focus of the current numerical control technology. At present, there have been all kinds of the Open CNC systems with high-speed and precision servo control boards, but they are too expensive. Therefore, developing an economical and practical motion controller is great significant for middle and small numerical control system

A Multi-Platform Compatible and Open Software Architecture for Computer Numerical Control Systems

Abstract. By analyzing the current open software architectures for PC-based master-slave Computer Numerical Control(CNC) systems and soft-CNC systems, this paper put forward a multi-platform compatible open software architecture for the two types of CNC systems. The architecture is composed by five different function layers: CNC presentation Layer, CNC Business Layer, CNC Data Layer, NC Interface Layer and NCK Layer. Firstly, the WPF and the MVVM pattern decouple the User Interface (UI) presentation and business logic. Secondly, the component technology is used to decouple the business logic and Numerical Control(NC) functions. Thirdly, the implementation of NC tasks is put into non-RT environment and RT environment. The experiment results of developing the application based on the architecture show that the layered software architecture improves the maintenance and development efficiency, and running the application in the “non-RT+RT” environment proves that the architecture is available for PC-based master-slave CNC systems and soft-CNC systems.

Research on ARM Numerical Control System

Abstract Computerized Numerical Control (CNC) machine tools is the foundation of modern manufacturing systems, whose advanced digital technology is the key to solve the problem of sustainable development of machine tool manufacturing industry. The paper is to design CNC system embedded on ARM and indicates the hardware design and the software systems supported. On the hardware side: the driving chip of the motor control unit, as the core of components, is MCX314AL of DSP motion control which is developed by NOVA Electronics Co., Ltd. of Japan. It make convenient to control machine because of its excellent performance, simple interface, easy programming. On the Software side, the uC/OS-2 is selected as the embedded operating system of the open source, which makes a detailed breakdown of the modules of the CNC system. Those priorities are designed according to their actual requirements. The ways of communication between the module and the interrupt response are so different that it guarantees real-time property and reliability of the numerical control system. Therefore, it not only meets the requirements of the current social precision machining, but has good man-machine interface and network support to facilitate a variety of craftsmen use.

Research on multi-robot open architecture of an intelligent CNC system based on parameter-driven technology

This paper presents a multi-robot open architecture of an intelligent computer numerical control (CNC) system based on parameter-driven technology that has been developed for flexible and high-efficiency manipulation. An open architecture control system capable of distributed processing of decision-making and extraction of task information provides a premise for intelligent control and flexible operation. Intelligent detection with database feedback based on real-time assignment of tasks is proposed to achieve dynamic modification of the processing trajectory. In the context of flexible task control, a multi-robot architecture with collision-free path planning and a novel programming approach based on parameter-driven technology are developed. The proposed CNC system has been successfully implemented and demonstrated on an H-beam steel-cutting task that requires flexible and accurate machining.

Research of Sheet-Fed Offset Damping System Green Printing Technology

Lithographic printing press must maintain a stable standard printing environment; we need to maintain the ink-water balance for achieve stability print quality. Not only stable for ink supply, but also stable supply of dampening solution from dampening circulation system. The study tries to conduct less proportion of alcohol to reduce emissions of volatile IPA, using green printing technology in the standard production. This study analyzed a variety of automatic sheet-fed offset press dampening system to study how to control the tank fluid additives, and reduce alcohol consumption. Design standard operation of "automatic green formula system“, the system should contain four main functions: purity water systems, precise formulation systems, circulated filtration system and computer numerical control system. Its purpose: to make the operation under the automated water quality standards, make stable print quality and increase printing capacity, increase product yield, reduce pollution. The water dampening system makes the quality and stability while reducing pollution emissions.

Performance analysis model for real-time Ethernet-based computer numerical control system

In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethernet, system architecture, time characteristic parameters of control-loop etc, a performance analysis model for real-time Ethernet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.

A universal NC program processor design and prototype implementation for CNC systems

Since the NC program standard RS274D was invented decades ago, most computer numerical control (CNC) providers have extended this standard a lot to adapt their own specific functions. Thus, one NC program cannot be used in different CNC systems. In order to process different types of NC programs, a universal NC program processor was proposed for CNC systems in this paper. This processor has a unique structure which consists of two main components. One is an NC dictionary, which stores the specific NC program specification. The other is an interpreting engine, which checks NC programs and generates the primitive canonical machining functions by referring to the dictionary. The dictionary is constructed through defining NC block templates, block execution order table, block syntax procedures, and interpreter library for each NC command. A prototype system has been built to evaluate the proposed design followed by a successful case study.

FPGA-Based Intelligent Software Hardening Chip for Computer Numerical Control System

In order to meet the development demands for high-speed and high-precision of Computer Numerical Control (CNC) machine tools, the equipped CNC systems begin to employ the technical route of software hardening. Making full use of the advanced performance of Large Scale Integrated Circuits (LSIC), this paper puts forward using Field Programmable Gates Array (FPGA) for the functional modules of CNC system, which is called Intelligent Software Hardening Chip (ISHC). The CNC system architecture with high performance is constructed based on the open system thought and ISHCs. The corresponding programs can be designed with Very high speed integrate circuit Hardware Description Language (VHDL) and downloaded into the FPGA. These hardening modules, including the arithmetic module, contour interpolation module, position control module and so on, demonstrate that the proposed schemes are reasonable and feasibility.

Research and Development on Miniature Teaching Computer Numerical Control Lathe Machine

An open double coordinates computer numerical control (CNC) system was developed, which was based on PC and PMAC motion controller card. A miniature and teaching CNC lathe machine was developed with a simple structure, low cost, small volume and suitability for teaching. The CNC system had the advantages of 2-axis linkage, program editing, manual operation, inching operation, simulation processing operation, automatic operation and dynamic display of the tracing. The system was based on the Windows XP platform. Its interface was friendly and it was convenient to manipulate.

An eXtended Manufacturing Integrated System for feature-based manufacturing with STEP-NC

Computer Numerical Control (CNC) feature-based programming with STandard for the Exchange of Product data model-compliant Numerical Control extends the collaborative model of manufacturing data exchange all along the numerical data chain. This study considers the mutations related to this approach from the manufacturing system level to the industrial enterprise as a whole. The eXtended Manufacturing Integrated System concept is introduced to fill in the gap of the current manufacturing data exchange bottleneck. It is composed of eXtended Computer Aided Design (CAD) and eXtended CNC systems to link the CAD model to the real machined part through the Manufacturing Information Pipeline. The contributions associated with these concepts are demonstrated through a validation platform implemented on industrial CNC manufacturing equipments.

Embedded Machine Tool CNC System Based on the ARM and MCX314

CNC(Computer Numerical Control) machine tool is the foundation and core of modern manufacturing systems, advanced CNC technology is the key to sustainable development of machine tool manufacturing industry. This thesis presents ARM as the main chip, motion control chip MCX314, the operating system using μC / OS-II, to build a CNC system development hardware platform and software platform, to explore the new ways for numerical control system development and design. This thesis can be divided into: CNC system hardware platform structures, including ARM and external hardware selection, hardware interface design and testing; MCX314 hardware platform design and testing; Software Platform, including the use of real-time operating system μC / OS-II to achieve the mission of the NC system, scheduling, management, μC / OS-II transplantation on ARM; MCX314 hardware platform building and testing; application framework built , program design and testing. Test results showed that: ARM as the main chip, MCX314 as a motion controller of the CNC system is feasible, its motion performance can meet the design requirements.

Solution of Software Test of Computerized Numerical Control (CNC) Systems

Software has been used more and more widely in CNC systems, the defects caused by soft­ware among all defects of a CNC device have been higher and higher as well. How to diagnose the defects caused by software in CNC device fast and effectively is the topic of this paper. This paper talks about the features of embedded soft­ware first, and then introduces a proved method used in software test and defect diagnosis by using software system test platform. We’ll use an instance to elaborate on it. We’ll make a general summary of this method at the end of the paper.

Optimization of tool wear ratio for automation computer numerical controlled system

The aim of this study is to minimize the tool wear during machining operations, which is a major green consideration in the precision CNC (computer numerical controlled) machining industry. In this paper, the orthogonal array of Taguchi experiment is selected for four parameters (cutting depth, feed rate, speed, tool nose runoff ) with three levels (low, medium, high) in optimizing the tool wear ratio for precision turning on an ECOCA-3807 CNC lathe. The tool wear ratio () is examined as the objective to achieve optimum machining parameters. Through the machined results from the CNC lathe, it is shown that the tool wear ratio from our optimum parameters is really improved comparing to that from benchmark parameters. This paper not only proposes an optimization approach using orthogonal array, but also contributes the satisfactory technique in minimizing tool wear ratio for the tool wear ratio in CNC turning with profound insight.

A New Aspheric Surfaces Polishing by Parallel Orthogonality Movement/Force Servomechanism

According to the all-pervading theory, the best strategy for multiaxis compliant control system is the famous hybrid movement/force control. Until now, the typical way to get it inclines to integrate force control with movement control into one numerical control (NC) interpolator. The more axes being taken for the interpolator, the lower calculating and computerizing speed and the greater errors are. Furthermore, the errors of movement control, including the position errors and pose errors, would inevitably disturb the processing of force control for their coupling relationship. In this paper, the orthogonal movement/force servo strategy is brought forward based on the orthogonality relation of force control and movement control. Combining with the processing of aspheric surfaces polishing, the paper develops a new three-axis computer numerical control (CNC) compliant polishing method and system by the hybrid orthogonal movement/force servomechanism, in which the force controlling and movement controlling are taken in its orthogonal complement space, respectively. Experiments show that this new polishing system is of great robustness for the change of slope and curvature of the aspheric surfaces and it can polish aspheric surfaces to get ultrasmooth surfaces at nanoscale.

A three-ply reconfigurable CNC system based on FPGA and field-bus

To reconfigure computer numerical control (CNC) system, the authors divide the reconfiguration technology of CNC system into three interactive levels: hardware system reconfiguration, software system reconfiguration, and module reconfiguration. On the software–hardware platform of CNC system designed in this study, hardware system reconfiguration is based on a rapid field programming of Field-Programmable Gate Array (FPGA) and performed with different FPGA configuration files. Meanwhile, software system reconfiguration is conducted through design, modification, selection, and configuration of different databases on a guiding software reconfiguration development platform. For modular reconfiguration, PROFIBUS-DP industry field-bus is involved as the communication media among function modules of CNC system, to facilitate the increase and decrease of modules. Finally, an application case of aforementioned reconfiguration methods is given. A CNC system with five synchronously moveable axes in total eight stepping axes is reconfigured successfully from the existing CNC system with three synchronously moveable axes in four ones.

Detection and research of RTX timer actual computing workload for ONC system based on RDTSC

The developing applications of opening computerized numerical control (CNC) system required hard real-time timer support, while the precision and stability of real-time extension (RTX) timer need to be strictly detected when applying to opening CNC system applications. By using RDTSC to count CPU basic clock cycle, which served as standard detected clock signal, the precision and stability of RTX timer was practically detected. The detected data from actual laboratory result provides the prediction ability of RTX timer actual computing workload for developer of opening CNC system applications.

FPGA implementation and application of PCI interface controller in bus based computer numerical control system

To meet the requirements for high speed and high accuracy machining,how to transmit large amounts of data fast and stably between operation system and peripheral interface becomes very important in bus based multi-processor advanced Computer Numerical Control(CNC) system.After analyzing the advantage of transmission application based on PCI in the CNC system,a PCI interface controller was designed in the main control chip FPGA on the CNC device's interface control board,also the key components of the internal structure of PCI interface controller,as well as its core state machine design were discussed in detail,then the method to use PCI interface controller in bus based CNC system was explained.Finally,the experimental platform was set up to verify the feasibility and effectiveness of the program.

5-axis Interpolation and Synchronous Servo Process with NURBS Method

Abstract Nowadays, NURBS (Non-Uniform Rational B-Spline) method is widely used in CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) to represent sculptured curves or surfaces. In this paper, we develop a 5-axis NURBS real-time interpolator and realize it in our developing CNC(Computer Numerical Control) system. At first, we use two NURBS curves to represent tool-tip and tool-axis path respectively. According to feedrate and Taylor series extension, servo-controlling signals of 5 axes are obtained for each interpolating cycle. Then, generation procedure of NC(Numerical Control) code with the presented method is introduced and the method how to integrate the interpolator into our developing CNC system is given. And also, the servo-controlling structure of the CNC system is introduced. Through the illustration, it has been indicated that the proposed method can enhance the machining accuracy and the spline interpolator is feasible for 5-axis CNC system.