：During machining the high accuracy non-circular part, normally the trajectory of non-circular part profile is generated, and then the fast response linear servo motor drive the cutting tool to do reciprocating moving, and control the cutting tool synchronously with the spindle.The control accuracy of the non-circular part trajectory is critical to affect the non-circular part CNC machining.Based on the periodic features of non-circular profile trajectory, the control algorithm which is hybrid control of PID and iterative learning control has been effectively developed for non-circular profile generation.Because the load disturbance can negatively affect the control accuracy, so the disturbance observer is integrated to the control algorithm.The final motion accuracy of linear actuator has been improved, and the machining accuracy of the non-circular turning is improved.

本文通过多年工作经验的总结，对机械设计复杂结构的有限单元分析方法中几个问题的处理进行了探讨，以便能更好地利用这种分析方法来进行机械设计。

机械制图是职业院校机械类专业非常重要的一门专业基础课,机械制图教学质量的好坏直接影响学生的职业生涯,为了提高机械制图教学质量,我院开展了机械制图一体化教学改革试点,将机械制图课堂搬到了多媒体机房,利用计算机绘图软件与机械制图的有机结合,较好的提高了机械制图的教学质量.

Due to their excellent performances such as mechanical,thermal,chemical,optical and electrical properties,polycrystalline diamond(PCD) are widely used in many fields.However,having high hardness and high wear resistance,PCD compacts are very hard to be machined.Electrical discharge and ultrasonic-assisted mechanical combined machining is an ideal method for PCD processing.On the basis of analyzing the principle of the combined method,the electrical discharge and ultrasonic-assisted mechanical combined machining process was realized by using bronze-bonded diamond grinding wheel.The relevance of the machining effects and the parameters of the combined machining method were studied.The experiment results show that parameters of pulse width,pulse interval,peak current,ultrasonic amplitude and open-circuit voltage affect the machining effects distinctly.

Detailed manufacturing information about the parts can help designers produce better designs. Detailed manufacturing information is conveyed to the designer through micro-circles within the concurrent design process for machined parts, focusing on instantaneous product design and process planning. The process has three key elements: a hierarchical architecture design of the concurrent process planning system, modeling and reengineering of the concurrent process planning, and modeling of information. The approach is successfully implemented and applied for concurrent design and process planning of some complicated parts.

<正>我国数控机床创新和发展的环境数控机床是20世纪最伟大的工程技术发明之一,已有近60多年的发展历史,成为对制造技术发展有着深远影响的共性工程技术。目前,机床数字控制技术仍处于方兴未艾的发展时期,世界各工业发达国家均给予了高度重视。我国数控机床的研究是从1958年开始的,大体上经历了数控机床、加工中心和柔性生产线三个里程碑。

The means of complex machining technology was reviewed at first,and then point of view of the generalized complex machining technology was mentioned,especially the concept of precision complex machining technology.Actions and significations of innovation in development of precision complex machining in manufacturing technology were discussed,that are important method to solve the key problem of process,new eyeshot to development in innovation and availability way to exalting key competition.Sequentially,the kinds of complex machining was reviewed,and four types of precision complex machining methods were recommended,that are ultoprecision grinding with complex bond micro-powder diamond whell,precision vibration grinding,polishing and lapping with abrasive tape,vertical precision turning-milling machining and chemistry-mechanical polishing machining.Finally applications,developments and regard problems of complex machining were discussed.

Metal microwires mean the metal wires with diameter less than 0.10 mm.The metal microwires have not only the characteristics of metal materials but also the special performances of nonmetal materials such as good electric conductivity,good thermal conductivity,high strength,high elasticity,good wear resistance and anti-corrosion,high temperature resistance,heat stability,better screening,antimagnetism,radiation protection,less electrostatic effect,and so on.Therefore the metal microwires are widely used in the various departments of the national economy.The development of the modern technologies urges the metal microwires to progress towards the high precision and minuteness,which puts forward higher request to the precision of diamond dies for drawing the metal microwires.The precision of the dies made in China is much lower than that of Japan and Germany products.The micro-ultrasonic machining of diamond dies for drawing the metal microwire was studied on the basis of the authors′earlier researches.High precision dies were developed with the dimension error of 0.42 μm and the roundness error of 0.18 μm.

This paper deals with a completely new dressing method, the soft-elastic dressing method, of dressing fine grain diamond wheels. Soft-elastic dressing equipment has been invented and the principle of the soft-elastic dressing method is explained. The studies that have been carried out are on the relationships between the elements of soft-elastic dressing and the dressing effects. Experiments into both dressing and grinding fully bear out that soft-elastic dressing has excellent truing efficiency, high truing precision and good sharpening results. In addition, soft-elastic dressing can be applied to all kinds of bonds.

One of the greatest invention of engineering technology was Numerical Control(NC)technology in 20thcentury,has been became the commonness engineering technology of the manufacturing technology with deep inference development.The means of numerical control technology of machine tool was reviewed,compare with the loom of spinning industry,the naissance of numerical control machine tool was discussed,and the development course and three landmark,that are Numerical Control(NC)machine tool,machine center and Flexible Manufacturing Product Line(FML),were concluded and summarized.The develop course of the first NC machine tool of Chine in 1958 and early period development of NC machine tool of China were introduced.Some existing questions of development with the NC technology of machine tool were analyzed,and correlative countermeasures were mentioned.

In this paper,a robust minimum-time control technique is presented for point-to-point motion of a linear positioning system with an ironless permanent magnet linear synchronous motor(ILPMLSM).For this system,a time-optimal control satisfying Pontryagin's minimum principle is in Bang-Bang fashion.A switching time computation algorithm using particle swarm optimization(PSO) is proposed to obtain bang-bang control law.Due to parameter variations and other disturbances,the obtained bang-bang control would result in undesirable chattering towards the end of the desired final state.To tackle this problem,a two-phase control scheme is developed in this work.In the first phase(gross motion control),a bang-bang control law is applied,while in the second phase(fine motion control) a fast terminal sliding mode control(FTSMC) technique is employed to guarantee the convergence of the state to the desired final state.The simulation results show that the proposed method is more applicable and the probability of tramped into local extremum is dramatically reduced.Experimental results demonstrate that the proposed control scheme is effective and robust against parameter variations and other disturbances.

The key technologies of the micro EDM(Electrical Discharge Machining)equipment are researched based on the requirements of micro EDM.A set of micro EDM equipment is developed successfully,including a precision micro EDM machine tool and a pulse power supply.The structures of some key parts of the tool are designed optimally,so that it has a very small deformation and a high motion precision.The power supply works stably,with a good performance of discharge and control.Through machining experiments,good machining effects are obtained stably:the dimension error of the micro slot is 5μm and the roundness error of the micro hole(whose diameter is 300μm)is below 3μm.It proves that the requirements of micro EDM will be met well with this type of equipment.

This paper presents a practical approach to applying variable spindle speed machining (VSM) to noncircular turning process, in which the cutting tool is driven by a fast tool servo and performs dynamic variable depth of cut machining. An enhanced closed loop dynamic model involving strong dynamic feedback between the machining process and the fast tool servo is thus developed. By using the spindle's angular position as the independent variable and Euler differential approximation, the system dynamics are described as a finite dimensional periodic time-varying discrete system, which in turn is converted to a time-invariant system using the lifted technique. The system stability becomes tractable by spectral radius analysis. Then, a criterion of the VSM stability index is used to evaluate the quantitative effects of VSM on noncircular turning systems and to design optimal VSM trajectory parameters. It is shown that a modest stability increase is obtained with the use of VSM. Experimental machining results are presented, which demonstrate the ability to increase noncircular turning stability using VSM, as well as the proposed VSM trajectory parameters design.

Fast tool servo (FTS) is one of the key technologies in both noncircular turning and non-axisymmetric turning fields. The researching history, structure characteristics and performance indices of FTS system were presented, and lots of existing FTSs were reviewed. Afterwards, four kinds of FTSs including piezoelectric FTS, magnetostrictive FTS, Lorentz force FTS and Maxwell force ( normal-stress electromagnetic force ) FTS were discussed, involving their working principles, configuration, applications, respective pros and cons. In addition, several cases of FTS’s applying in non-axisymmetric turning were given. The viewpoints are that ultrafast-response(>1000Hz) short-stroke(<100μm) FTS is the focus in current research, and both piezoelectric FTS and Maxwell force FTS are accessing to ultrafast-response; especially the Maxwell force, it is an excellent new principle for realizing ultrafast-response FTS.

The situation and feature are analyzed according to both history and modern,and the eternity of manufacturing technology and broad sense of manufacturing theory("Large Manufacturing")are discussed.In the same time,the core action and the development of process theory and technology is analyzed.In the last,the development directions of mechanical manufacturing science technology are mentioned.

A trajectory generation method which is based on NURBS interpolation is studied to improve the fitting accuracy and smoothness of non-circular cross section and obtain higher accuracy of the final non-circular profile control. After using the NURBS, the most optimized and smooth trajectory for the linear actuator can be obtained. For the purpose of machining the non-circular cross section by CNC turning, the fast response linear actuator has been used. The control algorithm which is compound control of proportional-integral-differential (PID) and iterative learning control has been developed for non-circular profile generation. By using the NURBS interpolation and the compound control of PID and iterative learning control, the final motion accuracy of linear actuator has been improved, therefore, the machining accuracy of the non-circular turning can be improved.

Electrical degree is an important variable in the SVPWM. It is critical to motor control. Due to the error of design and installation, it needs to correct the electrical angle before motor power on first time. A simple and precise method is proposed in this paper. Using only a DSP chip, it can achieve the correction task with low cost. Many times experiments on many kinds of motor illustrate stable and reliable of this method, as well as improve the correcting accuracy greatly.

In order to suppress the inherit force ripple of Permanent Magnet Linear Synchronous Motors to get a smooth velocity response,a compensation method based on NESO is proposed.The disturbances including force ripple are online observed by the NESO and compensated by a feed forward component.At the reference velocity of 0.1 m/s,the fluctuation range decreases from 6.75% to 1.23%.Both simulation and experimental results showed that the influence of the force ripple is effectively reduced,and thus resulted in a smoother velocity response.

In application of variable spindle speed machining to noncircular turning process, the tracking control of the fast tool servo yields a periodic sampling rate in the real-time domain. However, in the view of the angle domain, the sampling rate is constant. Moreover, the reference acceleration signal is easily available. This implies that it is advantageous to design the control system from the angle domain perspective, but the plant for a linear time-invariant system will become a periodically time-varying system. In this paper, the active disturbance rejection control strategy is applied to actively estimate the time-varying dynamics and other disturbances and compensate for them in the control law. The acceleration feed-forward strategy is employed to achieve better tracking performance. The stability analysis based on the lifting technique is proposed. Experimental machining results demonstrate the tracking performance of the proposed design, as well as the ability to increase machining stability using variable spindle speed machining.