软开关全桥电火花加工脉冲电源的设计

分析了移相全桥软开关电火花加工脉冲电源的工作原理，介绍了全桥逆变器软开关ZVZCS的实现过程及脉冲电源的结构与设计方法。     

电火花加工与脉冲电源浅述

电火花加工机床的社会拥有量将越来越大，与其它机床相比，其故障率相对为高，而故障基本集中于电源部分。本文通过对电源的工作原理，特别是电路构成作一介绍，并列举了线路实例，阐述各单元电路的特点和性能参数对电源可靠性的影响。     

微细电火花加工多模式脉冲电源的研究

根据微细电火花加工的特点及其对脉冲电源的要求,设计了以单片机和FPGA为控制核心的多模式微细电火花脉冲电源.介绍了该脉冲电源关键回路的实现方法,实验研究表明该电源可实现多种形式的脉冲放电加工.     

超声电火花同步复合加工用脉冲电源设计

研制了一种超声电火花同步复合加工用的半独立式Ｔｒ－ＲＣ脉冲电源。对电容的放电能量进行了功率最高输出控制，加强放电通道的消电离措施，提供了ＲＣ参数选择的严格公式。     

电火花加工脉冲电源电磁兼容技术研究

在对电火花加工中各种电磁干扰可能带来的危害进行分析研究的基础上，提出了抑制电磁干扰的措施，研制出了相应的电路，对所设计的抑制电磁干扰电路的工作原理、特点和电气参数选择等进行了研究，给出了相应电气元件参数选择的计算方法。     

基于FPGA的绝缘陶瓷电火花加工脉冲电源的研制

针对现有绝缘陶瓷电火花加工效率较低、加工质量较差的问题,通过分析绝缘陶瓷的间隙放电状态,研制基于现场可编程逻辑门阵列(FPGA)绝缘陶瓷的电火花加工脉冲电源。该电源可实现低阻火花放电的等电路脉宽模式和抑制有害脉冲放电的高频分组脉冲模式。在硬件上,脉冲电源采用模块化设计,由基于FPGA的主振模块、带LCD缓冲回路的MOSFET功率放大模块、基于四阈值电压电流比较法的间隙放电状态检测模块组成。结果表明:与常规脉冲电源相比,针对绝缘陶瓷氧化铝的加工,所研制的脉冲电源可有效提高低阻火花放电率,抑制有害脉冲放电状态;其加工速度为0.48 mm/min,提高了33%;电极相对损耗为132%,降低了16.9%;表面粗糙度为4.6μm,降低了22%;孔边和孔壁无显著微孔隙产生。该脉冲电源可有效提高绝缘陶瓷的加工效率和加工质量。     

电火花机床脉冲电源的评析

电火花机床脉冲电源的评析上海机械专科学校（上海２０００３１）庞述圣随着模具工业朝着高、精、尖的技术方向发展，电火花加工用的脉冲电源便愈来愈显示出它的重要性。可以说，模具电火花加工质量的好坏在很大程度取决于脉冲电源性能的好坏．判别某脉冲电源性能的优劣、...     

超声电火花同步复合加工用脉冲电源设计

研制了一种超声电火花同步复合加工用的半独立式Tr－RC脉冲电源。对电容的放电能量进行了功率最高输出控制，加强了放电通道的消电离措施，提供了RC参数选择的严格公式。     

组合式高速电火花小孔加工用脉冲电源的研制

分析了高速电火花小孔加工对脉冲电源的要求,研制出一种新型脉冲电源－－组合式高速电火花小孔加工脉冲电源。该电源采用模块化的设计思想,把电源划分成若干个模块,通过对功能模块的不同组合,使电源可以工作在等电池脉宽或晶体管控制的ＣＲ脉冲电源方式。     

State of the art electrical discharge machining (EDM)

Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests.In recent years, EDM researchers have explored a number of ways to improve the sparking efficiency including some unique experimental concepts that depart from the EDM traditional sparking phenomenon. Despite a range of different approaches, this new research shares the same objectives of achieving more efficient metal removal coupled with a reduction in tool wear and improved surface quality.This paper reviews the research work carried out from the inception to the development of die-sinking EDM within the past decade. It reports on the EDM research relating to improving performance measures, optimising the process variables, monitoring and control the sparking process, simplifying the electrode design and manufacture. A range of EDM applications are highlighted together with the development of hybrid machining processes. The final part of the paper discusses these developments and outlines the trends for future EDM research.     

基于DSC和FPGA的运动控制卡设计

针对四轴运动控制卡进行研究,设计了一种基于数字信号控制器DSC和FPGA双核架构的四轴数字量和模拟量运动控制卡;开发了数字脉冲输出模块、模拟量模块、标志位模块、编码器接收模块及接口电路等硬件;基于开发的硬件系统,实现了运动控制粗精两级插补算法,粗插补采用数据采样算法,精插补采用数字积分法,完成了控制卡软硬件调试。实验结果表明:控制卡实现了步进电机和伺服电机的多轴精确位置控制,性能稳定,可以满足多数工业场合应用。     

Advancing EDM through Fundamental Insight into the Process

This paper aims to show the prospects of electrical discharge machining (EDM) technology by interrelating recent achievements in fundamental studies on EDM with newly developed advanced application technologies. Although gap phenomena in EDM are very complicated and hence not yet very well understood, recent improvements in computers and electronic measuring instruments are contributing to new discoveries and inventions in EDM technology. Such newly acquired insight sometimes raises questions on the validity of the established theories of EDM phenomena, and EDM processes once believed to be impossible or unrealistic are now becoming practical.     

有源功率因数校正技术在脉冲电源设计中的应用

针对电火花加工的技术特点,在节能电火花加工脉冲电源的设计过程中应用了有源功率因数校正技术,使得整个节能电源系统的功率因数提高到0．95。     

基于FPGA的汽车主动悬架模糊自适应PID控制器设计

为改善乘车舒适性,建立1/4主动悬架模型,提出模糊自适应PID控制策略,并基于FPGA平台,应用VHDL语言在RTL级上实现模糊控制。该PID控制器以车身垂直速度的误差及误差变化率作为模糊控制器的输入,根据模糊规则推理,对PID参数进行在线优化,利用MATLAB/Simulink对模糊自适应PID控制器进行仿真。结果表明:具有模糊自适应PID控制器的主动悬架在提高车辆舒适性方面明显优于被动悬架。最后,采用FPGA设计方法,对模糊控制器的主要模块进行设计。     

Anomalous influence of polarity in sink EDM of titanium alloys

An anodic tool polarity is generally adopted in sink electrical discharge machining (EDM) to maximize material removal relative to tool wear. Sink EDM of Ti and Ti6Al4V is however atypical in that these materials necessitate a cathodic tool polarity. Adding to the intrigue is γ-TiAl, which machines better under the conventional anodic polarity. This research focused on clarifying the phenomena behind this interesting behavior by investigating removal mechanisms over a range of relevant process conditions. The anomaly is demonstrated to arise from the polarity-dependent nature and extent of TiC formation on the work surface, which significantly affects material removal.     

Reliability of electrode wear compensation based on material removal per discharge in micro EDM milling

This paper investigates the reliability of workpiece material removal per discharge (MRD) estimation for application in electrode wear compensation based on workpiece material removal. An experimental investigation involving discharge counting and automatic on the machine measurement of removed material volume was carried out in a range of process parameters settings from fine finishing to roughing. MRD showed a decreasing trend with the progress of the machining operation, reaching stabilization after a number of machined layers. Using the information on MRD and discharge counting, a material removal simulation tool was developed and validated.     

Machining Characteristics of EDM by Radio-frequency Plasma

An extension to the electrical discharge machining method by introduction of radio-frequency plasma is proposed. Sparking with the radio-frequency plasma can be generated in paraffin oil by simple electrical circuitry. In this paper, experimental investigations are described on the fundamental effects of the resonant frequency, type of electrode and workpiece materials on machining characteristics for high performance radio-frequency machining in paraffin oil. The results show that the removal rate and the electrode wear vary with the resonant frequency and type of electrode materials. The surface roughness can be reduced to less than 1μm Rz under suitable experimental conditions.     

Clarification of EDM gap phenomena using transparent electrodes

This paper describes the heat source diameter of single pulse discharge in electrical discharge machining. To observe the discharge plasma, SiC and Ga₂O₃ single crystals were used as the electrode material since they are optically transparent and electrically conductive. It was found that plasma diameter expands within a few microseconds after dielectric breakdown and the plasma diameter is much larger than the discharge crater. From the measured diameter of the crater, the heat source diameter was obtained by solving the inverse problem of heat conduction analysis, and it was found that the heat source diameter is smaller than the plasma diameter but larger than the crater diameter.     

基于FPGA的多轴旋转变压器解调系统的实现

旋转变压器因其高精度、高可靠性的优点广泛应用于工业控制的各个领域,专用解码芯片为核心的解调系统只能实现一对一的解调方式,不方便扩展。针对以上问题,提出以现场可编程门阵列为核心的多轴旋转变压器解调系统。该系统可以同时解调8个旋转变压器角度数据,采用前置CORDIC算法的闭环解码跟踪算法实现解码,解调精度高、速度快,适用于多轴联动控制系统中伺服电机角度的测量。通过实验验证了该系统的可行性,证明了该算法可以提高多轴解码系统的解码精度。