Research on cubic polynomial acceleration and deceleration control model for high speed NC machining

To satisfy the need of high speed NC (numerical control) machining, an acceleration and deceleration (acc/dec) control model is proposed, and the speed curve is also constructed by the cubic polynomial. The proposed control model provides continuity of acceleration, which avoids the intense vibration in high speed NC machining. Based on the discrete characteristic of the data sampling interpolation, the acc/dec control discrete mathematical model is also set up and the discrete expression of the theoretical deceleration length is obtained furthermore. Aiming at the question of hardly predetermining the deceleration point in acc/dec control before interpolation, the adaptive acc/dec control algorithm is deduced from the expressions of the theoretical deceleration length. The experimental result proves that the acc/dec control model has the characteristic of easy implementation, stable movement and low impact. The model has been applied in multi-axes high speed micro fabrication machining successfully.

MOTION VELOCITY SMOOTH LINK IN HIGH SPEED MACHINING

To deal with over-shooting and gouging in high speed machining, a novel approach for velocity smooth link is proposed. Considering discrete tool path, cubic spline curve fitting is used to find dangerous points, and according to spatial geometric properties of tool path and the kinematics theory, maximum optimal velocities at dangerous points are obtained. Based on method of velocity control characteristics stored in control system, a fast algorithm for velocity smooth link is analyzed and formulated. On-line implementation results show that the proposed approach makes velocity changing more smoothly compared with traditional velocity control methods and improves productivity greatly.

Real-Time Data and Visualization Monitoring of Computer Numerical Control Machine Tools Based on Hyper Text Markup Language 5

In order to ensure the safety,quality and efficiency of computer numerical control(CNC)machine tool processing,a real-time monitoring and visible solution for CNC machine tools based on hyper text markup language(HTML)5 is proposed.The characteristics of the real-time monitoring technology of CNC machine tools under the traditional Client/Server(C/S)structure are compared and analyzed,and the technical drawbacks are proposed.Web real-time communication technology and browser drawing technology are deeply studied.A real-time monitoring and visible system for CNC machine tool data is developed based on Metro platform,combining WebSocket real-time communication technology and Canvas drawing technology.The system architecture is given,and the functions and implementation methods of the system are described in detail.The practical application results show that the WebSocket real-time communication technology can effectively reduce the bandwidth and network delay and save server resources.The numerical control machine data monitoring system can intuitively reflect the machine data,and the visible effect is good.It realizes timely monitoring of equipment alarms and prompts maintenance and management personnel.

Specialized Numerical Control Plasma Cutting Machine

The large thermal cutting equipment——The DHG. CNC numerical control plasma cutting machine is produced by The Ha’erbin Welding & Cutting Equipment Co. It specializes in the precise formation and baiting of nonferrous boards and thin carbon steel plates at a high speed. It avoids the disadvantage of flame cutting, which cannot cut nonferrous and thin steel plates.

CPS Modeling of CNC Machine Tool Work Processes Using an Instruction-Domain Based Approach

Building cyber-physical system(CPS) models of machine tools is a key technology for intelligent manufacturing. The massive electronic data from a computer numerical control(CNC) system during the work processes of a CNC machine tool is the main source of the big data on which a CPS model is established. In this work-process model, a method based on instruction domain is applied to analyze the electronic big data, and a quantitative description of the numerical control(NC) processes is built according to the G code of the processes. Utilizing the instruction domain, a work-process CPS model is established on the basis of the accurate, real-time mapping of the manufacturing tasks, resources, and status of the CNC machine tool. Using such models, case studies are conducted on intelligent-machining applications, such as the optimization of NC processing parameters and the health assurance of CNC machine tools.

The Innovation of CNC Machine Interface Based on DNC System

This paper describes the innovation schemes of the interface of a CNC machine which cannot communicate with a computer by a Direct Numerical Control(DNC)interface and the functions of a DNC interface system.One architecture of hardware and software of a practi- cal single-chip computer based on DNC interface system developed by the authors is given. Without any change of the original hardware and software,this DNC interface system has been used to innovate the CNC machine's interface to implement the direct communication between a computer and a CNC machine and to achieve no tape transmission of a part program and ma- chine parameters.It has been demonstrated that this DNC interface system has certain practical values in improving the reliability,efficiency and production management of CNC/NC machine.

Patterns of CNC Machine Tool Reference Return and Its Trouble Shooting Methods

This paper presents four patterns of reference-return positions for CNC machine tools and analyses some causes of return reference troubles by showing typical examples of trouble shooting.Finally,it introduces several methods of trouble shooting.

高速动车组铝合金零件CNC铣削加工工艺研究

高速动车组应用了较多铝合金零件。此类零件存在较高的加工装夹难度,若无法准确把握加工工艺,易出现加工缺陷。结合铝合金零件性能,详细分析零件计算机数字控制机床(Computer Numerical Control,CNC)铣削加工工艺特点,并从多个角度研究铝合金零件的CNC铣削加工工艺及其热处理技术。合理优化加工参数和热处理技术,可提高铝合金零件的加工质量和机械性能,促进高速动车组铝合金零件加工工艺水平的提升,进而推动我国高速动车组的发展。

基于CNC车铣复合机床的异形零件高效加工工艺研究

近年来,制造业对异形复杂零件的加工效率和精度提出了更高要求。计算机数字控制机床(Computer Numerical Control,CNC)车铣复合机床集车削和铣削功能于一体,在加工复杂异形零件方面具有独特的优势。提出基于CNC车铣复合机床的异形零件高效加工工艺,包括工艺规划与编程、夹具选择、加工执行与监控等关键环节。通过优化刀具路径、切削参数,采用自适应加工策略和在线测量补偿手段,大幅提升了异形零件的加工效率、精度和表面质量,为制造业的转型升级提供了有力支持。

Intelligent NURBS Interpolator Based on the Adaptive Feedrate Control

To satisfy the need for high-speed and high-accuracy machining of NURBS curve. Firstly the form of NURBS curve is analyzed and Talor＇s expansion of the parameter u with respect to time t is used to obtain the algorithm of the first order approximation interpolation. Secondly, based on the algorithm of the controlled chord error interpolator, an intelligent interpolation algorithm of the adaptive feedrate control is proposed. According to the actual machining capacity of machine tools, this algorithm uses look-ahead method, which dispenses with the complicated computation of the end point estimation of NURBS curve, to analyze the curve segment required by the maximum deceleration distance. Thus, the feedrate could decrease in advance and vary with the curvature and the variation ratio of curvature, which makes machining motion quite smooth. Not only could high accuracy and fine surface quality be achieved during high-speed machining, but also the overload of cutter tools is avoided on comers. Finally, in order to facilitate the calculation of interpolation, the dynamic matrix representation and efficient algorithm of curvature computation of the NURBS curve are presented,

虚拟CNC的齿轮测量中心

介绍了传统CNC齿轮测量中心的发展现状,结合虚拟现实技术,提出了CNC齿轮测量中心新的发展方向—虚拟CNC齿轮测量中心,同时介绍了虚拟CNC齿轮测量中心的概念、组成、实现方法。通过对虚拟CNC齿轮测量中心工作过程的仿真和分析,证明虚拟CNC齿轮测量中心基本可以表达真实CNC测量中心的几何形状和测量过程。

CNC系统开发与应用

介绍一种基于单片机控制的CNC系统,阐述了系统的硬件组成、软件设计和工作原理。该系统已成功应用于数控车床、数控铣床等机床控制中,其投资成本小,性价比高,完全满足企业生产的各项技术要求,特别适合中小企业及个体企业投资需要。

基于四次位移曲线的CNC数控系统的研究

对加减速控制方法在CNC数控系统中的运用进行了总体介绍。对开发的四次位移曲线加减速方法数控系统的总体结构进行了介绍,包括硬件和软件部分。然后对加减速在本系统中的具体应用方法做了说明,并通过一个加工实例,对常见的几种加减速方法进行了验证和比较。

高速加工机床的现代CNC控制技术

阐述了适用于高速加工的CNC控制系统的基本构成、控制技术及其高速加工功能,并结合具体的CNC控制系统实例,分析了现代CNC控制系统在高速加工机床中的功能特点。

CNC加工中心前馈控制的插补运算实现

插补及加减速控制的精度和速度是CNC系统的重要指标,决定了CNC机床实现高速高精度加工的的性能优劣。本文依据控制论,探讨在插补运算中运用多段NC代码前瞻优化处理实现CNC机床的前馈控制,使之根据不同的曲率半径在最短的时间内不断地调整进给速度,从而胜任高精度复杂曲面轮廓的加工。

CNC系统中传统插补法的改进-弧度分割法

首先介绍了CNC系统中常用的插补算法-逐点比较插补算法的工作原理,并对其进行了速度分析。为了在此基础上进一步提高数控机床加工速度,提出了一种新的插补算法-弧度分割插补法,在对其工作原理进行了详细介绍之后,进一步进行了加工速度和加工精度分析,通过分析,证明弧度分割法无论是在加工速度和精度上都有了很大的提高。

基于STEP的高速CNC系统研究

针对高速加工中数控编程瓶颈问题,遵从STEP标准、面向对象的数据模型,建立STEP-NC数据模型。并以实例进行分析,初步得出特征造型系统的模型。

浅谈CAD/CAM/CNC技术

介绍了计算机辅助设计CAD及计算机辅助制造CAM的主要软件系统及其特点 ,同时介绍了CNC数控技术的特点及其发展前景 ,阐述了CAD/CAM

一种高速CNC雕铣机数控系统的设计

文章简要介绍了当前数控系统的开放化趋势,以及基于PC的数控系统的不同开放化形式,在此基础上,详细介绍了一种高速数控雕铣机数控系统的模块化设计思想及其基于CPLD的四轴位置控制卡的设计。

基于扰动观测的非圆零件CNC加工的迭代学习复合PID控制

在加工高精度非圆零件时,通常先产生非圆零件的轮廓生成直线伺服器的运动轨迹,然后高响应直线伺服器按照生成的运动轨迹进行往复运动,并和驱动非圆零件的主轴同步控制。非圆零件加工轨迹的控制精度是影响零件数控加工的重要因素。提出一种基于扰动观测的数字PID和迭代学习复合控制算法,根据非圆轮廓轨迹表现的周期性特征,使用数字PID和迭代学习控制的方法,可以有效达到非圆零件加工的控制精度,加工过程中的扰动同样影响零件的加工精度,通过扰动观测器来实现对扰动的有效反馈补偿控制,提高系统的控制精度,从而使非圆截面的切削控制精度得到提高,非圆零件的加工精度也可以得到显著提高。