伺服电机
1.伺服电机的定义
伺服电动机又称执行电动机，在自动控制系统中，用作执行元件，把所收到的电信号转换成电动机轴上的角位移或角速度输出。分为直流和交流伺服电动机两大类，其主要特点是，当信号电压为零时无自转现象，转速随着转矩的增加而匀速下降。伺服电机在伺服系统中控制机械元件运转的发动机.是一种补助马达间接变速装置。伺服电机可使控制速度,位置精度非常准确。将电压信号转化为转矩和转速以驱动控制对象。转子转速受输入信号控制，并能快速反应，在自动控制系统中作执行元件，且具有机电时间常数小、线性度高、始动电压低等特点。
2.伺服电机工作原理
1.伺服主要靠脉冲来定位，基本上可以这样理解，伺服电机接收到1个脉冲，就会旋转1个脉冲对应的角度，从而实现位移，因为，伺服电机本身具备发出脉冲的功能，所以伺服电机每旋转一个角度，都会发出对应数量的脉冲，这样，和伺服电机接受的脉冲形成了呼应，或者叫闭环，如此一来，系统就会知道发了多少脉冲给伺服电机，同时又收了多少脉冲回来，这样，就能够很精确的控制电机的转动，从而实现精确的定位，可以达到0.001mm。有刷电机成本低，结构简单，启动转矩大，调速范围宽，控制容易，需要维护，但维护方便（换碳刷），产生电磁干扰，对环境有要求。无刷电机体积小，重量轻，出力大，响应快，速度高，惯量小，转动平滑，力矩稳定。控制复杂，容易实现智能化，其电子换相方式灵活，可以方波换相或正弦波换相。电机免维护，效率很高，运行温度低，电磁辐射很小，长寿命，可用于各种环境。
2.交流伺服电机也是无刷电机，分为同步和异步电机，目前运动控制中一般都用同步电机，它的功率范围大，可以做到很大的功率。大惯量，最高转动速度低，且随着功率增大而快速降低。因而适合做低速平稳运行的应用。
3.永磁交流伺服电动机简介
20世纪80年代以来，随着集成电路、电力电子技术和交流可变速驱动技术的发展，
永磁交流伺服驱动技术有了突出的发展，各国著名电气厂商相继推出各自的交流伺服电动机和伺服驱动器系列产品并不断完善和更新。交流伺服系统已成为当代高性能伺服系统的主要发展方向，使原来的直流伺服面临被淘汰的危机。90年代以后，世界各国已经商品化了的交流伺服系统是采用全数字控制的正弦波电动机伺服驱动。交流伺服驱动装置在传动领域的发展日新月异。永磁交流伺服电动机同直流伺服电动机比较，主要优点有：⑴无电刷和换向器，因此工作可靠，对维护和保养要求低。⑵定子绕组散热比较方便。⑶惯量小，易于提高系统的快速性。⑷适应于高速大力矩工作状态。⑸同功率下有较小的体积和重量。自从德国MANNESMANN的Rexroth公司的Indramat分部在1978年汉诺威贸易博览会上正式推出MAC永磁交流伺服电动机和驱动系统，这标志着此种新一代交流伺服技术已进入实用化阶段。到20世纪80年代中后期，各公司都已有完整的系列产品。整个伺服装置市场都转向了交流系统。早期的模拟系统在诸如零漂、抗干扰、可靠性、精度和柔性等方面存在不足，尚不能完全满足运动控制的要求，近年来随着微处理器、新型数字信号处理器（DSP）的应用，出现了数字控制系统，控制部分可完全由软件进行，分别称为摪胧只瘮或抟旌鲜綌、撊只瘮的永磁交流伺服系统。到目前为止，高性能的电伺服系统大多采用永磁同步型交流伺服电动机，控制驱动器多采用快速、准确定位的全数字位置伺服系统。日本安川电机制作所推出的小型交流伺服电动机和驱动器，其中D系列适用于数控机床（最高转速为1000r/min，力矩为0.25～2.8N.m），R系列适用于机器人（最高转速为3000r/min，力矩为0.016～0.16N.m）。之后又推出M、F、S、H、C、G 六个系列。20世纪90年代先后推出了新的D系列和R系列。这样，只用了几年时间形成了八个系列（功率范围为0.05～6kW）较完整的体系，满足了工作机械、搬运机构、焊接机械人、装配机器人、电子部件、加工机械、印刷机、高速卷绕机、绕线机等的不同需要。以生产机床数控装置而著名的日本法那克（Fanuc）公司，在20世纪80年代中期也推出了S系列（13个规格）和L系列（5个规格）的永磁交流伺服电动机。L系列有较小的转动惯量和机械时间常数，适用于要求特别快速响应的位置伺服系统。日本其他厂商，例如：三菱电动机（HC-KFS、HC-MFS、HC-SFS、HC-RFS和HC-UFS系列）、东芝精机（SM系列）、大隈铁工所(BL系列）、三洋电气
（BL系列）、立石电机（S系列）等众多厂商也进入了永磁交流伺服系统的竞争行列。美国著名的伺服装置生产公司Gettys曾一度作为Gould 电子公司一个分部（Motion Control Division），生产M600系列的交流伺服电动机和A600 系列的伺服驱动器。后合并到AEG，恢复了Gettys名称，推出A700全数字化的交流伺服系统。I.D.（Industrial Drives）是美国著名的科尔摩根（Kollmorgen）的工业驱动分部，曾生产BR-210、BR-310、BR-510 三个系列共41个规格的无刷伺服电动机和BDS3型伺服驱动器。自1989年起推出了全新系列设计的掺鹣盗袛（Goldline）永磁交流伺服电动机，包括B（小惯量）、M（中惯量）和EB（防爆型）三大类，有10、20、40、60、80五种机座号，每大类有42个规格，全部采用钕铁硼永磁材料，力矩范围为0.84～111.2N.m，功率范围为0.54～15.7kW。配套的驱动器有BDS4（模拟型）、BDS5（数字型、含位置控制）和Smart Drive（数字型）三个系列，最大连续电流55A。法国Alsthom集团在巴黎的Parvex工厂生产LC系列（长型）和GC系列（短型）交流伺服电动机共14个规格，并生产AXODYN系列驱动器。原苏联为数控机床和机器人伺服控制开发了两个系列的交流伺服电动机。其中ДBy系列采用铁氧体永磁，有两个机座号，每个机座号有3种铁心长度，各有两种绕组数据，共12个规格，连续力矩范围为7～35N.m。2ДBy系列采用稀土永磁，6个机座号17个规格，力矩范围为0.1～170N.m，配套的是3ДБ型控制器。近年日本松下公司推出的全数字型MINAS系列交流伺服系统，其中永磁交流伺服电动机有MSMA系列小惯量型，功率从0.03～5kW，共18种规格；中惯量型有MDMA、MGMA、MFMA三个系列，功率从0.75～4.5kW，共23种规格,MHMA 系列大惯量电动机的功率范围从0.5～5kW，有7种规格。
伺服电机原理
1.交流伺服电动机
交流伺服电动机定子的构造基本上与电容分相式单相异步电动机相似.其定子上装有两个位置互差90°的绕组，一个是励磁绕组Rf，它始终接在交流电压Uf上；另一个是控制绕组L，联接控制信号电压Uc。所以交流伺服电动机又称两个伺服电动机。交流伺服电动机的转子通常做成鼠笼式，但为了使伺服电动机具有较宽的调速范围、线性的机械特性，无
“自转”现象和快速响应的性能，它与普通电动机相比，应具有转子电阻大和转动惯量小这两个特点。目前应用较多的转子结构有两种形式：一种是采用高电阻率的导电材料做成的高电阻率导条的鼠笼转子，为了减小转子的转动惯量，转子做得细长；另一种是采用铝合金制成的空心杯形转子，杯壁很薄，仅0.2-0.3mm，为了减小磁路的磁阻，要在空心杯形转子内放置固定的内定子.空心杯形转子的转动惯量很小，反应迅速，而且运转平稳，因此被广泛采用。交流伺服电动机在没有控制电压时，定子内只有励磁绕组产生的脉动磁场，转子静止不动。当有控制电压时，定子内便产生一个旋转磁场，转子沿旋转磁场的方向旋转，在负载恒定的情况下，电动机的转速随控制电压的大小而变化，当控制电压的相位相反时，伺服电动机将反转。交流伺服电动机的工作原理与分相式单相异步电动机虽然相似，但前者的转子电阻比后者大得多，所以伺服电动机与单机异步电动机相比，有三个显著特点：1、起动转矩大由于转子电阻大，与它可使临界转差率S0＞1，这样不仅使转矩特性（机械特性）更接近于线性，而且具有较大的起动转矩。因此，当定子一有控制电压，转子立即转动，即具有起动快、灵敏度高的特点。2、运行范围较广 3、无自转现象，正常运转的伺服电动机，只要失去控制电压，电机立即停止运转。当伺服电动机失去控制电压后，它处于单相运行状态，由于转子电阻大，定子中两个相反方向旋转的旋转磁场与转子作用所产生的两个转矩特性（T1－S1、T2－S2曲线）以及合成转矩特性（T－S曲线）交流伺服电动机的输出功率一般是0.1-100W。交流伺服电动机运行平稳、噪音小。但控制特性是非线性，并且由于转子电阻大，损耗大，效率低，因此与同容量直流伺服电动机相比，体积大、重量重，所以只适用于0.5-100W的小功率控制系统。
2.伺服电机选型方法
1.与步进电机的性能比较
步进电机作为一种开环控制的系统，和现代数字控制技术有着本质的联系。在目前国内的数字控制系统中，步进电机的应用十分广泛。随着全数字式交流伺服系统的出现，交流伺服电机也越来越多地应用于数字控制系统中。为了适应数字控制的发展趋势，运动控制系统中大多采用步进电机或全数字式交流伺服电机作为执行电动机。虽然两者在控制方式
上相似（脉冲串和方向信号），但在使用性能和应用场合上存在着较大的差异。现就二者的使用性能作一比较。
一、控制精度不同：两相混合式步进电机步距角一般为 1.8°、0.9°，五相混合式步进电机步距角一般为0.72 °、0.36°。也有一些高性能的步进电机通过细分后步距角更小。如三洋公司（SANYO DENKI）生产的二相混合式步进电机其步距角可通过拨码开关设置为1.8°、0.9°、0.72°、0.36°、0.18°、0.09°、0.072°、0.036°，兼容了两相和五相混合式步进电机的步距角。交流伺服电机的控制精度由电机轴后端的旋转编码器保证。以三洋全数字式交流伺服电机为例，对于带标准2000线编码器的电机而言，由于驱动器内部采用了四倍频技术，其脉冲当量为360°/8000=0.045°。对于带17位编码器的电机而言，驱动器每接收131072个脉冲电机转一圈，即其脉冲当量为360°/131072=0.0027466°，是步距角为1.8°的步进电机的脉冲当量的1/655。
二、低频特性不同，步进电机在低速时易出现低频振动现象。振动频率与负载情况和驱动器性能有关，一般认为振动频率为电机空载起跳频率的一半。这种由步进电机的工作原理所决定的低频振动现象对于机器的正常运转非常不利。当步进电机工作在低速时，一般应采用阻尼技术来克服低频振动现象，比如在电机上加阻尼器，或驱动器上采用细分技术等。交流伺服电机为恒力矩输出，即在其额定转速（一般为2000RPM或3000RPM）以内，都能输出额定转矩，在额定转速以上为恒功率输出。
三、过载能力不同步进电机一般不具有过载能力。交流伺服电机具有较强的过载能力。以山洋交流伺服系统为例，它具有速度过载和转矩过载能力。其最大转矩为额定转矩的二到三倍，可用于克服惯性负载在启动瞬间的惯性力矩。步进电机因为没有这种过载能力，在选型时为了克服这种惯性力矩，往往需要选取较大转矩的电机，而机器在正常工作期间又不需要那么大的转矩，便出现了力矩浪费的现象。
四．运行性能不同步进电机的控制为开环控制，启动频率过高或负载过大易出现丢步或堵转的现象，停止时转速过高易出现过冲的现象，所以为保证其控制精度，应处理好升、降速问题。交流伺服驱动系统为闭环控制，驱动器可直接对电机编码器反馈信号进行采样，
内部构成位置环和速度环，一般不会出现步进电机的丢步或过冲的现象，控制性能更为可靠。
五、2.选型计算方法
一、转速和编码器分辨率的确认。
二、电机轴上负载力矩的折算和加减速力矩的计算。
三、计算负载惯量，惯量的匹配，安川伺服电机为例，部分产品惯量匹配可达50倍，但实际越小越好，这样对精度和响应速度好。
四、再生电阻的计算和选择，对于伺服，一般2kw以上，要外配置。
五、电缆选择，编码器电缆双绞屏蔽的，对于安川伺服等日系产品绝对值编码器是6芯，增量式是4芯。
3.伺服电机安装注意事项
1、伺服电机油和水的保护 A：伺服电机可以用在会受水或油滴侵袭的场所，但是它不是全防水或防油的。因此，伺服电机不应当放置或使用在水中或油侵的环境中。B：如果伺服电机连接到一个减速齿轮，使用伺服电机时应当加油封，以防止减速齿轮的油进入伺服电机C：伺服电机的电缆不要浸没在油或水中。
2、伺服电机电缆→减轻应力 A：确保电缆不因外部弯曲力或自身重量而受到力矩或垂直负荷，尤其是在电缆出口处或连接处。B：在伺服电机移动的情况下，应把电缆（就是随电机配置的那根）牢固地固定到一个静止的部分（相对电机），并且应当用一个装在电缆支座里的附加电缆来延长它，这样弯曲应力可以减到最小。C：电缆的弯头半径做到尽可能大。
3、伺服电机允许的轴端负载 A：确保在安装和运转时加到伺服电机轴上的径向和轴向负载控制在每种型号的规定值以内。B：在安装一个刚性联轴器时要格外小心，特别是过度的弯曲负载可能导致轴端和轴承的损坏或磨损C：最好用柔性联轴器，以便使径向负载低于允许值，此物是专为高机械强度的伺服电机设计的。D：关于允许轴负载，请参阅“允许的轴负荷表”（使用说明书）。
4.直流伺服电机特点
一、直流无刷电机特点：
1.转动惯量小、启动电压低、空载电流小；
2.弃接触式换向系统，大大提高电机转速，最高转速高达100 000rpm；
3.无刷伺服电机在执行伺服控制时，无须编码器也可实现速度、位置、扭矩等的控制；
4.不存在电刷磨损情况，除转速高之外，还具有寿命长、噪音低、无电磁干扰等特点；
二、直流有刷伺服电机特点：
1.体积小、动作快反应快、过载能力大、调速范围宽；
2.低速力矩大, 波动小，运行平稳；
3..低噪音,高效率；
4.后端编码器反馈（选配）构成直流伺服等优点；
使用范围：直流伺服电机可应用在是火花机、机械手、精确的机器等。可同时配置2500P/R高分析度的标准编码器及测速器，更能加配减速箱、令机械设备带来可靠的准确性及高扭力。调速性好，单位重量和体积下，输出功率最高，大于交流电机，更远远超过步进电机。多级结构的力矩波动小。
Servo motor
1. Servo motor definition
Also known as the implementation of the motor servo motor, the automatic control system for the implementation of components to convert signals received from the motor shaft angular displacement or angular velocity output.DC and AC servo motor is divided into two categories, the main feature is that when the signal voltage is zero, no rotation of the phenomenon, the increasing speed with uniform torque decreased.Servo motors to control mechanical servo system in the operation of the engine components. Is a servomotors device.Servo motor can control the speed, position accuracy is very accurate.The voltage signal into a torque and speed to drive the control object.Rotor speed by the input signal control, and can respond rapidly, in the automatic control system for the implementation of components, and has electrical and mechanical time constant, linear and high initiating voltage low.
2. Servo motor works
1. Servo mainly rely on impulse to locate, basically can be understood, the servo motor receives
a pulse, a pulse will rotate the corresponding point of view, in order to achieve the displacement, because the servo motor itself has issued a pulse function, so the servoEach motor to rotate a point of view, is issued by the corresponding number of pulses, so that the pulse and servo motors to accept the formation of the echo, or called closed-loop, this way, the system will know the number of pulses sent to the servo motor, while the number of receivedpulse came back, so that we can very accurately control the motor rotation, in order to achieve accurate positioning, can reach 0.001mm.DC servo motor into brush and brushless motors.Brush motor low cost, simple structure, starting torque, wide speed range, easy control, need to maintain, but easy to maintain (replacement carbon brushes), generate electromagnetic interference, the environment requirements.So it can be used for cost-sensitive general industrial and civil applications.Brushless motor, small size, light weight, large output, fast response, high speed,
small inertia, rotational smoothness, torque and stability.Control complex, easy to implement intelligent, flexible way of their electronic commutation, the commutation can be square wave or sinusoidal commutation.Motor maintenance-free, high efficiency, low operating temperature, electromagnetic radiation is very small, long-life, can be used for a variety of environments.
2. Brushless AC servo motor is divided into synchronous and asynchronous motors, motion control in the current synchronous motor is generally used, and its power range, can do a lot of https://www.doczj.com/doc/3c11326388.html,rge inertia, the maximum rotation speed is low, and with the power increases rapidly decreased.Thus suitable for applications that run on low speed steady.
3. Servo motor rotor is permanent magnet, the drive control of the U / V / W three-phase power to form fields, the rotor in the magnetic field under the rotation, while the motor comes with encoder feedback signal to the drive, the drive according to the feedback valuecompared with the target value, adjusting the angle of the rotor rotation.Depends on the accuracy of the servo motor encoder accuracy (lines).
Question:
AC servo motors and brushless DC servo motor function, what is the difference?
A: AC servo better because a sine wave control, torque ripple small.DC servo is a trapezoidal wave.But the DC servo is relatively simple, cheap.
3. Introduction permanent magnet AC servo motor
update products.AC servo system has become a contemporary high-performance servo systems the main developm 80 years since the 20th century, with the integrated circuits, power electronics and AC variable speed drive technology, permanent magnet AC servo drive technology with outstanding development, national electrical manufacturers have launched their own well-known AC servo motor and servo drive seriesand continue to improve and ent direction, so that the original DC servo facing the crisis of being eliminated.90 years later, the world has been commercialized by AC servo digital control system is a sine wave motor servo
drive.AC servo drive the rapid development of the field in the transmission.Permanent magnet AC servo motor compared with DC servo motor, the main advantages are: ⑴ without brush and commutator, it is reliable and maintenance requirements for maintenance and low.⑵ cooling the stator winding more convenient.⑶ inertia is small, easy-to improve the system fast.⑷ adapted to high-speed high torque working condition.⑸under the same power, smaller size and weight.Since the German MANNESMANN of Rexroth Indramat division in the company's Hanover Trade Fair 1978 was officially launched MAC permanent magnet AC servo motor and drive system, which marks this new generation of AC servo technology has entered the practical stage.To the late 20th century, 80 years, the company has a complete line of products.The servo-device market are turning to the exchange system.Early analog systems such as zero-drift, interference, reliability, accuracy and flexibility in areas such as lack of motion control is still not fully meet the requirements, in recent years with the microprocessor, the new digital signal processor (DSP) applicationsthe emergence of digital control system, the control section can be carried out entirely by the software, called Jiang hazy or Tuan Shen Jing only fresh coarse hempen fabric, valiant only Shen of the permanent magnet AC servo system.So far, high-performance servo systems mostly use electrical permanent magnet synchronous AC servo motor, control the drive to use more fast, accurate positioning of the all-digital servo system.Typical manufacturers such as Siemens of Germany, the United States and Japan Kollmorgen companies such as Panasonic and Yaskawa.Yaskawa Electric has launched a small-scale production of AC servo motors and drives, in which D series for CNC machine tools (maximum speed of 1000r/min, torque is 0.25 ~ 2.8Nm), R series is suitable for the robot (the highest speed of 3000r/min, torque is 0.016 ~ 0.16Nm).Launched after the M, F, S, H, C, G six series.90 20th century, has introduced a new D-series and R series.Rectangular wave drive from the old series, 8051 to control the sine wave drive, 80C, 154CPU and gate array chip control, torque ripple from 24% to 7%, and improved reliability.Thus, the formation of only a few years,
eight series (power range of 0.05 ~ 6kW) more complete system to meet the working machinery, transportation agencies, welding robots, assembly robots, electronic components, processing machinery, printing presses, high speed winding machine, winding machines for different https://www.doczj.com/doc/3c11326388.html,C equipment to produce the famous Japanese law that g (Fanuc) company, in the 20th century has introduced the mid-80s S series (13 specifications), and L series (5 specifications) of the permanent magnet AC servo motor.L Series has a smaller moment of inertia and the mechanical time constant, particularly for applications that require fast response servo system.Other Japanese manufacturers, such as: Mitsubishi Motors (HC-KFS, HC-MFS, HC-SFS, HC-RFS and HC-UFS series), Toshiba Seiki (SM series), Okuma Iron Works (BL series), Sanyo Electric(BL series), standing stones motor (S series) and many other manufacturers have entered the permanent magnet AC servo system fray.Germany Rexroth (Rexroth) The MAC Indramat Division Series AC servo motor Total 7 Frame 92 specifications.Germany's Siemens (Siemens)'s IFT5 series three-phase permanent magnet AC servo motor standard and short form is divided into two categories, a total of 98 species of 8 frame size specifications.Allegedly the same series AC servo motor and DC servo motor output torque compared IHU series, which weighs only 1 / 2, supporting the transistor PWM drive 6SC61 series, the most for 6-axis motor control.Bosch (BOSCH) ferrite magnets produced the SD series (17 standard) and rare earth permanent magnet of the SE series (8 specs) AC servo motor and drive controller Servodyn SM series.American production companies Gettys servo device as Gould Electronics, once a division of (Motion Control Division), production of M600 series A600 series AC servo motor and servo drives.After the merger to the AEG, Gettys name restored, the introduction of A700 all-digital AC servo system.U.S. AB (ALLEN-BRADLEY) 1326-based production company driver division ferrite permanent magnet AC servo motor and servo controller PWM AC 1391.Frame size motors including 3 of 30 specifications.ID (Industrial Drives) is a famous Cole Morgan (Kollmorgen) of industrial drives division, has produced BR-210, BR-310, BR-510 a total of 41 specifications of
the three series of brushless servo motor and servo BDS3drive.Since 1989, launched a new series designed solely doped Jian Pirates (Goldline) permanent magnet AC servo motor, including the B (small inertia), M (Middle Inertia) and EB (explosion proof) three categories, 10,20,40,60,80 five frame sizes, each of 42 categories of specifications, all using NdFeB permanent magnet, torque range of 0.84 ~ 111.2Nm, a power range of 0.54 ~ 15.7kW.Supporting the drive has BDS4 (analog), BDS5 (digital type, with position control) and the Smart Drive (digital type) of three series, the maximum continuous current of 55A.Goldline Series represents contemporary art in permanent magnet AC servo technology.Ireland's Inland formerly a division of Kollmorgen abroad, now merged into the AEG, the production of DC servo motors, DC torque motor and servo amplifier is known.Production BHT1100, 2200,3300 three frame sizes of 17 kinds of specifications of SmCo permanent magnet AC servo motor and eight controllers.French Alsthom Group factory in Paris Parvex LC series (long form) and GC series (short) 14 AC servo motor specifications, and production AXODYN series of drives.The former Soviet Union for the CNC machine tools and robots servo control developed two series of AC servo motor.One ДBy series uses ferrite magnets, there are two frame sizes, frame sizes are 3 for each core length, each with two winding data, a total of 12 specifications, a continuous torque range of 7 ~ 35N.m.2ДBy series uses rare earth permanent magnet, 6 frame size 17 specifications, the torque range is 0.1 ~ 170N.m, supportin g the 3ДБ controller.In recent years, Panasonic has introduced the all-digital AC servo system based MINAS series, in which permanent magnet AC servo motor with MSMA series of small inertia-type, power from 0.03 ~ 5kW, a total of 18 kinds of specifications; the inertia type with MDMA, MGMA, MFMA threeseries, the power from 0.75 ~ 4.5kW, 23 kinds of specifications, MHMA series of large inertia motor power range from 0.5 ~ 5kW, 7 kinds of specifications.Samsung developed in recent years, all-digital AC servo motor and drive system, which FAGA AC servo motor series of CSM, CSMG, CSMZ, CSMD, CSMF, CSMS, CSMH, CSMN, CSMX a variety of models, the power from 15W ~ 5kW.Now often used (Powerrate)
This comprehensive index as the servo motor quality factor, measuring a variety of AC and DC servo motor contrast and dynamic response performance stepper motor.Continuous motor power, said the rate of change (rated) torque and rotor inertia ratio.Change rate is calculated by power analysis, the permanent magnet AC servo motor technology indicators for the United States ID, Goldline Series is the best, followed by Germany's Siemens in IFT5 series.
Principle of the servo motor
1. AC servo motor
AC servo motor stator phase structure is essentially single-phase capacitor induction motor similar. The stator is equipped with 90 ° difference between the two locations each winding, one field winding Rf, it is always connected to the AC voltage Uf; anotheris the control winding L, link control signal voltage Uc.Therefore, the two AC servo motor servo motors, also known as.AC servo motors are usually made of squirrel-cage rotor, but in order to make the servo motor has a wide speed range, the mechanical properties of the linear, no "rotation" phenomenon and the rapid response of the performance, it is compared with ordinary motor should bewith the rotor resistance and a small moment of inertia of these two characteristics.Rotor structure is currently used more often in two forms: one is the use of high resistivity conductive material made of high resistivity conducting bar of squirrel cage rotor, in order to reduce the rotational inertia of the rotor, rotor do slender; otherOne is made of aluminum alloy hollow cup-shaped rotor, Beibi thin, only 0.2-0.3mm, in order to reduce the reluctance of magnetic circuit, to be placed inside the hollow cup-shaped rotor fixed stator. hollow cupRotor moment of inertia is small, responsive, and smooth operation, so it is widely used.AC servo motor in the absence of control voltage, the stator field windings, only the magnetic field pulse generated by the rotor stationary.When a control voltage, the stator generates a rotating magnetic field, rotating magnetic field along the direction of the rotor rotation, in the case of constant load, the motor speed with the size of the control voltage changes, when the control voltage of the opposite phase, the servo motorwill be reversed.The working principle of AC servo motor with split phase single phase induction motor although similar, but the former is much greater than the latter of rotor resistance, so the induction motor servo motor, compared with stand-alone, there are three significant features: 1, high starting torqueAs a large rotor resistance, the torque curve shown in Figure 3, curve 1, with ordinary asynchronous motor torque curve than 2, a marked difference.It
will enable the critical slip S0> 1, so that not only the torque characteristics (mechanical properties) is closer to linear, and has a larger starting torque.Therefore, when one has control of stator voltage, rotor turning once, that has a quick start, high sensitivity.2, 3, wide operating range, no rotation of the phenomenon, the normal operation of the servo motor, as long as the loss of control voltage, the motor stop running.When the voltage of the servo motor control is lost, it is running single-phase, due to a large rotor resistance, stator rotating in the opposite direction of the role of rotating magnetic field generated by the rotor torque characteristics of the two (T1-S1, T2-S2 curves) and the synthesis of torque characteristics (T-S curve) AC servo motor output power is generally 0.1-100W.When the power frequency is 50Hz, voltage 36V, 110V, 220,380 V; when the power frequency is 400Hz, voltage 20V, 26V, 36V, 115V and other.AC servo motor to run smoothly, low noise.However, non-linear control characteristics, and because a large rotor resistance, loss, low efficiency, and is therefore compared with the capacity of DC servo motor, bulky, heavy weight, it applies only to a small 0.5-100W power control system.
2. Servo motor selection method
1. And compare the performance of the stepper motor
As an open-loop stepper motor control system, and modern digital control technology are intrinsically linked.In the current domestic digital control system, the stepper motor is widely used.With the all-digital AC servo-systems, AC servo motor also increasingly used in digital control systems.In order to meet the development trend of digital control, motion control systems they use digital stepper motors or AC servo motor as the implementation of the motor.While both are similar in the control (pulse train and direction signal), but in applications where performance and there are big differences.Performance of both is to make a comparison.
Control accuracy are different: two-phase hybrid step motor step angle is generally 1.8 °, 0.9 °, five-phase hybrid stepping motor step angle is usually 0.72 °, 0.36 °.There are also some
high-performance stepper motor through after the breakdown of a smaller step angle.Such as Sanyo (SANYO DENKI) production of two-phase hybrid step motor step angle by its DIP switch is set to 1.8 °, 0.9 °, 0.72 °, 0.36 °, 0.18 °, 0.09 °, 0.072 °, 0.036 °compatible with the two-phase and five-phase hybrid stepping motor step angle.Precision AC servo motor control back from the motor shaft rotary encoder guarantee.To Sanyo all-digital AC servo motor, for example, the standard for the 2000 line encoder with the motor, since the internal drive, four-frequency technology using a pulse equivalent to 360 ° / 8000 = 0.045 °.For the encoder with the motor 17, the driver receives 131 072 pulses per motor revolution, that is, a pulse equivalent to 360 ° / 131072 = 0.0027466 °, a step angle of 1.8 ° stepper motor pulse equivalent1 / 655.
Different frequency characteristics, the stepper motor at low speeds prone to low frequency vibration.Vibration frequency and load conditions and drive performance, generally considered no-load off the motor frequency half the frequency.This works by the stepper motor vibration frequency determined by the normal operation of the machine is very negative.When the stepper motor in low speed, generally should be used to overcome the low frequency vibration damping phenomena, such as additional damper on the motor, or drive with subdivision techniques.AC servo motor is running very smoothly, even if it does not appear in the low-speed vibration.AC servo system with resonance suppression, can cover the lack of mechanical stiffness, and function within the system has a frequency analysis (FFT), can detect mechanical resonance point, easy system tuning.
The different torque-frequency characteristics, the stepper motor output torque decreases with speed increases, and at higher speeds would drop dramatically, so its maximum operating speed is generally at 300 ~ 600RPM.AC servo motor for constant torque output, which in its rated speed (typically 2000RPM or 3000RPM) or less, can output rated torque above the rated speed constant power output.Fourth, generally do not overload with various stepper motor overload.AC
servo motor with a strong overload.AC servo system to Sanyo, for example, it has the speed and torque overload overload.Its maximum torque is two to three times the rated torque can be used to overcome the inertia of the load moment of inertia at the start moment.Stepper motor because there is no such overload, in the selection order to overcome this moment of inertia, often need to select a larger motor torque, while the machine during normal operation and does not require so much torque, giving rise to a torquewasting phenomenon.
Five different operating performance stepper motor control for the open-loop control, start frequency is too high or too prone to lose the load step or the phenomenon of stall, stop rotating speed is too high when the phenomenon prone to overshoot, so as to ensure their controlaccuracy, should handle up, spin-down problem.AC servo drive system for closed loop control, the drive can be directly on the motor encoder feedback signal is sampled, the internal structure of the position loop and speed loop, generally will not be lost step or stepper motor overshoot phenomenon, the control performance more reliable.Six-speed response performance of different stepper motors to accelerate from standstill to operating speed (typically several hundred per minute, rpm) 200 ~ 400 ms.AC servo system is better acceleration performance to Sanyo 400W AC servo motor, for example, accelerates from zero to its rated speed of 3000RPM is only a few milliseconds, fast start and stop can be used to control the situation requires.In summary, the AC servo system is superior in many performance stepper motor.But in some less demanding situations are often to do with the implementation of the stepper motor motor.Therefore, the control system design process control requirements to be taken into account, costs, and many other factors, the choice of the appropriate motor control.
2. Selection method
First, the speed and encoder resolution of confirmation.
Second, the motor shaft load torque conversion and processing gear torque calculations.
Third, calculate the load inertia, inertia of the match, Yaskawa servo motors, for example, some
products match up to 50 times the inertia, but the actual smaller the better, so good on the accuracy and response speed.
Fourth, the calculation of resistance and choice of regeneration, for the server, usually more than 2kw to external configuration.
Fifth, cable selection, the encoder cable shielded twisted pair, and for other Japanese Yaskawa servo system product is 6-cell absolute encoder, incremental is 4 core.
3. Servo Motor Installation Notes
1, the servo motor oil and water conservation A: servo motor can be used in water or oil droplets will be affected by the invasion of the place, but it is not fully waterproof or anti-oil.Therefore, the servo motor should not be placed or used in water or oil intrusion in the environment.B: If the servo motor connected to a reduction gear, use the servo motor fuel should be sealed to prevent the reduction gear oil into the servo motor C: servo motor cable not immersed in oil or water.
2, servo motor cable to reduce stress → A: Make sure the cable is not due to external bending moment, or by their own weight or vertical load, especially in the cable outlet or connection.B: In the case of the servo motor moves, should the cable (that is configured with the motor Flanagan) is firmly fixed to a stationary part of the (relative motor), and should be installed in the cable with a bearing in the attached cables to extendit, so the bending stress can be minimized .C: cable bend radius be as large as possible.
3, the servo motor allows the shaft load A: make sure when you add in the installation and operation of the servo motor shaft in radial and axial load control within the specified value for each model.B: When installing a rigid coupling to be cautious, especially over the curved shaft and bearing load may cause damage or wear C: best to use a flexible coupling, so that the radial load below the allowable value,This material is designed for high mechanical strength of the servo motor design.D: axial load on the permit, please refer to the "permissible axle load table"
(Manual).
4, the servo motor is installed Note A: In the install / remove components to the servo motor shaft coupling, do not directly tap with a hammer shaft.(Direct beat hammer shaft, the other side of the servo motor shaft encoder to be knocked bad) B: strive to align the shaft to the best state (on a bad vibration or bearing damage may result.)
4. DC servo motor characteristics
First, the DC brushless motor features:
1. A small moment of inertia, low starting voltage, load current is small;
2. Disposable contact change to the system, greatly improving the motor speed, maximum speed up to 100 000rpm;
3. Brushless servo motor servo control in the implementation, the encoder can also be achieved without the speed, position, torque control;
4. There is no brush wear, in addition to high speed, but also has a long life, low noise, electromagnetic interference and other characteristics;
Second, the DC brush servo motor characteristics:
1. The volume is small, the fast response quick, overloading capacity, wide speed range;
2. Low-speed torque, and fluctuations in small, smooth;
3 .. low noise, high efficiency;
4. Backend encoder feedback (optional) constitute the advantages of the DC servo;
Use: DC servo motor can be used in a spark machine, robot, precise machinery.Can also configure the 2500P / R analysis of the degree of high standard encoder and tachometer, with gear box plus more, so that the accuracy of machinery and equipment to bring reliable and high torque.Speed is good, unit weight and volume, the output power of the highest, more than AC motors, and much higher than the stepper motor.Multi-level structure of the torque ripple small.
(文档含英文原文和中文翻译) 中英文翻译 平面设计 任何时期平面设计可以参照一些艺术和专业学科侧重于视觉传达和介绍。采用多种方式相结合，创造和符号，图像和语句创建一个代表性的想法和信息。平面设计师可以使用印刷，视觉艺术和排版技术产生的最终结果。平面设计常常提到的进程，其中沟通是创造和产品设计。 共同使用的平面设计包括杂志，广告，产品包装和网页设计。例如，可能包括产品包装的标志或其他艺术作品，举办文字和纯粹的设计元素，如形状和颜色统一件。组成的一个最重要的特点，尤其是平面设计在使用前现有材料或不同的元素。 平面设计涵盖了人类历史上诸多领域，在此漫长的历史和在相对最近爆炸视觉传达中的第20和21世纪，人们有时是模糊的区别和重叠的广告艺术，平面设计和美术。毕竟，他们有着许多相同的内容，理论，原则，做法和语言，有时同样的客人或客户。广告艺术的最终目标是出售的商品和服务。在平面
设计，“其实质是使以信息，形成以思想，言论和感觉的经验”。 在唐朝（ 618-906 ）之间的第4和第7世纪的木块被切断打印纺织品和后重现佛典。阿藏印在868是已知最早的印刷书籍。 在19世纪后期欧洲，尤其是在英国，平面设计开始以独立的运动从美术中分离出来。蒙德里安称为父亲的图形设计。他是一个很好的艺术家，但是他在现代广告中利用现代电网系统在广告、印刷和网络布局网格。 于1849年，在大不列颠亨利科尔成为的主要力量之一在设计教育界，该国政府通告设计在杂志设计和制造的重要性。他组织了大型的展览作为庆祝现代工业技术和维多利亚式的设计。 从1892年至1896年威廉?莫里斯凯尔姆斯科特出版社出版的书籍的一些最重要的平面设计产品和工艺美术运动，并提出了一个非常赚钱的商机就是出版伟大文本论的图书并以高价出售给富人。莫里斯证明了市场的存在使平面设计在他们自己拥有的权利，并帮助开拓者从生产和美术分离设计。这历史相对论是，然而，重要的，因为它为第一次重大的反应对于十九世纪的陈旧的平面设计。莫里斯的工作，以及与其他私营新闻运动，直接影响新艺术风格和间接负责20世纪初非专业性平面设计的事态发展。 谁创造了最初的“平面设计”似乎存在争议。这被归因于英国的设计师和大学教授Richard Guyatt，但另一消息来源于20世纪初美国图书设计师William Addison Dwiggins。 伦敦地铁的标志设计是爱德华约翰斯顿于1916年设计的一个经典的现代而且使用了系统字体设计。 在20世纪20年代，苏联的建构主义应用于“智能生产”在不同领域的生产。个性化的运动艺术在俄罗斯大革命是没有价值的，从而走向以创造物体的功利为目的。他们设计的建筑、剧院集、海报、面料、服装、家具、徽标、菜单等。 Jan Tschichold 在他的1928年书中编纂了新的现代印刷原则，他后来否认他在这本书的法西斯主义哲学主张，但它仍然是非常有影响力。 Tschichold ，包豪斯印刷专家如赫伯特拜耳和拉斯洛莫霍伊一纳吉，和El Lissitzky 是平面设计之父都被我们今天所知。 他们首创的生产技术和文体设备，主要用于整个二十世纪。随后的几年看到平面设计在现代风格获得广泛的接受和应用。第二次世界大战结束后，美国经济的建立更需要平面设计，主要是广告和包装等。移居国外的德国包豪斯设计学院于1937年到芝加哥带来了“大规模生产”极简到美国;引发野火的“现代”建筑和设计。值得注意的名称世纪中叶现代设计包括阿德里安Frutiger ，设计师和Frutiger字体大学;保兰德，从20世纪30年代后期，直到他去世于1996年，采取的原则和适用包豪斯他们受欢迎的广告和标志设计，帮助创造一个独特的办法，美国的欧洲简约而成为一个主要的先驱。平面设计称为企业形象;约瑟夫米勒，罗克曼，设计的海报严重尚未获取1950年代和1960年代时代典型。 从道路标志到技术图表，从备忘录到参考手册，增强了平面设计的知识转让。可读性增强了文字的视觉效果。 设计还可以通过理念或有效的视觉传播帮助销售产品。将它应用到产品和公司识别系统的要素像标志、颜色和文字。连同这些被定义为品牌。品牌已日益成为重要的提供的服务范围，许多平面设计师，企业形象和条件往往是同时交替使用。
Step Motor Motor&&Servo Motor Systems and Controls Motion Architect?Software Does the Work for You...Configure,Diagnose,Debug Compumotor’s Motion Architect is a Microsoft?Windows?-based software development tool for6000Series products that allows you to automatically generate commented setup code,edit and execute motion control programs,and create a custom operator test panel.The heart of Motion Architect is the shell,which provides an integrated environment to access the following modules. ?System Configurator—This module prompts you to fill in all pertinent set-up information to initiate motion.Configurable to the specific6000Series product that is selected,the information is then used to generate actual6000-language code that is the beginning of your program. ?Program Editor—This module allows you to edit code.It also has the commands available through“Help”menus.A user’s guide is provided on disk. ?Terminal Emulator—This module allows you to interact directly with the6000product.“Help”is again available with all commands and their definitions available for reference.?Test Panel—You can simulate your programs,debug programs,and check for program flow using this module. Motion Architect?has been designed for use with all6000Series products—for both servo and stepper technologies.The versatility of Windows and the6000Series language allow you to solve applications ranging from the very simple to the complex. Motion Architect comes standard with each of the6000Series products and is a tool that makes using these controllers even more simple—shortening the project development time considerably.A value-added feature of Motion Architect,when used with the6000 Servo Controllers,is its tuning aide.This additional module allows you to graphically display a variety of move parameters and see how these parameters change based on tuning values. Using Motion Architect,you can open multiple windows at once.For example,both the Program Editor and Terminal Emulator windows can be opened to run the program,get information,and then make changes to the program. On-line help is available throughout Motion Architect,including interactive access to the contents of the Compumotor6000Series Software Reference Guide. SOLVING APPLICATIONS FROM SIMPLE TO COMPLEX Servo Control is Yours with Servo Tuner Software Compumotor combines the6000Series servo controllers with Servo Tuner software.The Servo Tuner is an add-on module that expands and enhances the capabilities of Motion Architect?. Motion Architect and the Servo Tuner combine to provide graphical feedback of
译文资料： 机器人 首先我介绍一下机器人产生的背景，机器人技术的发展，它应该说是一个科学技术发展共同的一个综合性的结果，同时，为社会经济发展产生了一个重大影响的一门科学技术，它的发展归功于在第二次世界大战中各国加强了经济的投入，就加强了本国的经济的发展。另一方面它也是生产力发展的需求的必然结果，也是人类自身发展的必然结果，那么随着人类的发展，人们在不断探讨自然过程中，在认识和改造自然过程中，需要能够解放人的一种奴隶。那么这种奴隶就是代替人们去能够从事复杂和繁重的体力劳动，实现人们对不可达世界的认识和改造，这也是人们在科技发展过程中的一个客观需要。 机器人有三个发展阶段，那么也就是说，我们习惯于把机器人分成三类，一种是第一代机器人，那么也叫示教再现型机器人，它是通过一个计算机，来控制一个多自由度的一个机械，通过示教存储程序和信息，工作时把信息读取出来，然后发出指令，这样的话机器人可以重复的根据人当时示教的结果，再现出这种动作，比方说汽车的点焊机器人，它只要把这个点焊的过程示教完以后，它总是重复这样一种工作，它对于外界的环境没有感知，这个力操作力的大小，这个工件存在不存在，焊的好与坏，它并不知道，那么实际上这种从第一代机器人，也就存在它这种缺陷，因此，在20世纪70年代后期，人们开始研究第二代机器人，叫带感觉的机器人，这种带感觉的机器人是类似人在某种功能的感觉，比如说力觉、触觉、滑觉、视觉、听觉和人进行相类比，有了各种各样的感觉，比方说在机器人抓一个物体的时候，它实际上力的大小能感觉出来，它能够通过视觉，能够去感受和识别它的形状、大小、颜色。抓一个鸡蛋，它能通过一个触觉，知道它的力的大小和滑动的情况。第三代机器人，也是我们机器人学中一个理想的所追求的最高级的阶段，叫智能机器人，那么只要告诉它做什么，不用告诉它怎么去做，它就能完成运动，感知思维和人机通讯的这种功能和机能，那么这个目前的发展还是相对的只是在局部有这种智能的概念和含义，但真正完整意义的这种智能机器人实际上并没有存在，而只是随着我们不断的科学技术的发展，智能的概念越来越丰富，它内涵越来越宽。 下面我简单介绍一下我国机器人发展的基本概况。由于我们国家存在很多其
频谱感知技术外文翻译文献 (文档含中英文对照即英文原文和中文翻译) 译文： 一种新的协作频谱感知算法 摘要 该文提出了一种在认知无线网络控制信道带宽受限条件下基于信任度的双门限协同频谱感知算法。首先每个认知用户基于双检测门限独立进行频谱感知，但只有部分可靠的认知用户通过控制信道向认知无线网络基站发送本地感知结果。当所有的用户都不可靠时，选取信任度最高的认知用户发送本地感知结果进行判决。理论分析和仿真表明，同常规能量检测算法相比较，该算法能够在控制信道带宽受限条件下，以较少的网络开销获得更好的频谱感知性能。 关键词：认知无线电；频谱感知；信任度；双门限 1引言 随着无线通信技术的飞速发展，有限的频谱资源与不断增长的无线通信需求的矛盾越来越突出。然而根据现有的固定分配频谱资源策略，绝大多数频谱资源得不到有效利用。据FCC 的调查统计，70%的已分配频谱资源没有得到有效利用]1[。为了提高频谱资源的利用率，认知无线电技术由Joseph Mitola Ⅲ提出并得到了广泛的关注]5[]2[ 。频谱感知技术是认知无线电网络的支撑技术之一。通常它又可以分为
能量检测法、匹配滤波器法和循环平稳特征法[4]。能量检测算法因为应用简单且无需知道任何授权用户信号的先验知识成为研究热点。认知用户在接入授权频带之前，必须首先感知该频带空闲即授权用户没有工作，否则会对授权用户造成干扰。一旦授权用户重新工作，认知用户必须退避，实现在不对授权用户产生干扰的情况下对频谱资源的共享。由于实际信道中的多径和阴影效应，单个认知用户频谱感知的性能并不乐观，针对这个问题D. Cabric 等人提出了协同频谱感知算法[5]-[6]。协同频谱感知算法性能较好，但是当认知用户数量很大的时候，控制信道的带宽将不够用。文献[7]中提出了一种在控制信道带宽受限条件下的基于双检测门限的频谱感知算法，该算法能够以较小的网络开销，获得接近普通单门限频谱检测算法的性能。针对认知无线电频谱感知的需要，本文提出了认知无线电环境下一种基于信任度的双门限协同频谱感知算法。该算法中每个认知用户基于双检测门限独立进行频谱感知，但只有部分可靠的认知用户通过控制信道向认知无线网络基站发射感知报告。当所有的用户都不可靠时，选取信任度最高的认知用户发射感知报告进行判决。本文对该算法进行了性能分析并通过仿真表明，本文方法比较常规能量检测算法，在减小网络开销的同时提高了检测性能。 2系统模型 假设一个认知无线电网络有N 个认知用户和一个认知无线网络基站，如图1 所示。认知无线网络基站负责管理和联系N 个认知用户，在收到认知用户的检测报告后做出最终判决。 图1. 认知无线电网络示意图 频谱感知的实质是一个二元假设问题，即 01 (),,()()()(),n t H x t h t s t n t H ?=??+? （1）
加工中心数控技术 出处：数控加工中心的分类以及各自特点 出版社:化学工业出版社; 第1版 (2009年3月16日) 作者：徐衡、段晓旭 加工中心是典型的集高技术于一体的机械加工设备，它的发展代表了一个国家设计制造的水平也大大提高了劳动生产率，降低了劳动成本，改善了工人的工作环境，降低了工人的劳动强度。本文经过对不同运动方案和各部件的设计方案的定性分析比较确定该教立式加工中心的进给传动方案为：采用固定床身，电主轴通过安装座安装在床身导轨的滑座上，床身导轨采用滚动导轨，可以实现Y 方向的进给运动。由X-Y双向精密数控工作台带动工件完成X，Y两个方向的进给运动;X，Y，Z三个方向的进给运动均滚珠丝杠，并由交流伺服电机驱动。导轨、滚珠丝杠有相应的润滑、防护等装置。 加工中心（英文缩写为CNC 全称为Computerized Numerical Control）：是带有刀库和自动换刀装置的一种高度自动化的多功能数控机床。在中国香港，台湾及广东一代也有很多人叫它电脑锣。 工件在加工中心上经一次装夹后，数字控制系统能控制机床按不同工序，自动选择和更换刀具，自动改变机床主轴转速、进给量和刀具相对工件的运动轨迹及其他辅助机能，依次完成工件几个面上多工序的加工。并且有多种换刀或选刀功能，从而使生产效率大大提高。 加工中心数控机床是一种装有计算机数字控制系统的机床，数控系统能够处理加工程序，控制机床完成各种动作。与普通机床相比，数控机床能够完成平面曲线和空间曲面的加工，加工精度和生产效率都比较高，因而应用日益广泛。 数控机床的组成 一般来说，数控机床由机械部分、数字控制计算机、伺服系统、PC控制部分、液压气压传动系统、冷却润滑和排泄装置组成。数控机床是由程序控制的，零件的编程工作是数控机床加工的重要组成部分。伺服系统是数控机床的驱动部分，计算机输出的控制命令是通过伺服系统产生坐标移动的。普通的立式加工中心有三个伺服电机，分别驱动纵向工作台、横向工作台、主轴箱沿X向、Y向、Z向运动。X、Y、Z是互相垂直的坐标轴，因而当机床三坐标联动时可以加工空
I. City and The Landscape (1) Overview of Landscape Design Landscape design, first, is a people's thinking activity, performed as an art activity.Diversified thoughts formed complex diverse landscape art style. Contemporary landscape design apparently see is the diversity of the landscape forms,in fact its essence is to keep the closing up to the natural order system, reflected the more respect for human beings, more in-depth perspective of the nature of human's reality and need, not to try to conquer the nature.it is not even imitating natural, but produce a sense of belonging. Landscape is not only a phenomenon but the human visual scene. So the earliest landscape implications is actually city scene. Landscape design and creation is actually to build the city. (2) The Relationship Between Landscape and Urban City is a product of human social, economic and cultural development, and the most complex type. It is vulnerable to the artificial and natural environmental conditions of interference. In recent decades, with worldwide the acceleration of urbanization, the urban population intensive, heavy traffic, resource shortage,
数控加工中心技术发展趋势及对策 原文来源：Zhao Chang-ming Liu Wang-ju (CNC Machining Process and equipment, 2002,China) 一、摘要 Equip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment. Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry, Keywords:Numerical ControlTechnology, E quipment,industry 二、译文 数控技术和装备发展趋势及对策 装备工业的技术水平和现代化程度决定着整个国民经济的水平和现代化程度，数控技术及装备是发展新兴高新技术产业和尖端工业（如信息技术及其产业、生物技术及其产业、航空、航天等国防工业产业）的使能技术和最基本的装备。马克思曾经说过“各种经济时代的区别，不在于生产什么，而在于怎样生产，用什么劳动资料生产”。制造技术和装备就是人类生产活动的最基本的生产资料，而数控技术又是当今先进制造技术和装备最为核心的技术。当今世界各国制造业广泛采用数控技术，以提高制造能力和水平，提高对动态多变市场的适应能力和竞争能力。此外，世界上各工业发达国家还将数控技术及数控装备列为国家的战
人工智能的形成及其发展现状分析 冯海东 （长江大学管理学院荆州434023） 摘要：人工智能的历史并不久远，故将从人工智能的出现、形成、发展现 状及前景几个方面对其进行分析，总结其发展过程中所出现的问题，以及发展现状中的不足之处，分析其今后的发展方向。 关键词：人工智能，发展过程，现状分析，前景。 一．引言 人工智能最早是在1936年被英国的科学家图灵提出，并不为多数人所认知。 当时，他编写了一个下象棋的程序，这就是最早期的人工智能的应用。也有著名的“图灵测试”，这也是最初判断是否是人工智能的方案,因此，图灵被尊称为“人工智能之父”。人工智能从产生到发展经历了一个起伏跌宕的过程，直到目前为止，人工智能的应用技术也不是很成熟，而且存在相当的缺陷。 通过搜集的资料，将详细的介绍人工智能这个领域的具体情况，剖析其面临的挑战和未来的前景。 二．人工智能的发展历程 1. 1956年前的孕育期 (1) 从公元前伟大的哲学家亚里斯多德(Aristotle)到16世纪英国哲学家培根(F. Bacon)，他们提出的形式逻辑的三段论、归纳法以及“知识就是力量”的警句，都对人类思维过程的研究产生了重要影响。 （2）17世纪德国数学家莱布尼兹(G..Leibniz)提出了万能符号和推理计算思想，为数理逻辑的产生和发展奠定了基础，播下了现代机器思维设计思想的种子。而19世纪的英国逻辑学家布尔（G. Boole）创立的布尔代数，实现了用符号语言描述人类思维活动的基本推理法则。 （3） 20世纪30年代迅速发展的数学逻辑和关于计算的新思想，使人们在计算机出现之前，就建立了计算与智能关系的概念。被誉为人工智能之父的英国天才的数学家图灵（A. Tur-ing）在1936年提出了一种理想计算机的数学模型，即图灵机之后,1946年就由美国数学家莫克利（J. Mauchly）和埃柯特（J. Echert）研制出了世界上第一台数字计算机，它为人工智能的研究奠定了不可缺少的物质基础。1950年图灵又发表了“计算机与智能”的论文，提出了著名的“图灵测试”，形象地指出什么是人工智能以及机器具有智能的标准，对人工智能的发展产生了极其深远的影响。 （4） 1934年美国神经生理学家麦克洛奇(W. McCulloch) 和匹兹(W. Pitts )建立了第一个神经网络模型，为以后的人工神经网络研究奠定了基础。 2. 1956年至1969年的诞生发育期 (1)1956年夏季，麻省理工学院（MIT)的麦卡锡（J．McCarthy）、明斯基（M. Minshy）、塞尔夫里奇（O. Selfridge)与索罗门夫(R. Solomonff)、 IBM的洛
无线射频识别技术外文翻译参考文献(文档含中英文对照即英文原文和中文翻译) 翻译： 当前无线射频识别技术应用略述 摘要 无线射频识别技术可以自动识别多目标并以非接触式方式移动目标。越来越多的零售商、银行、交通管理系统、展览及物流供应商将这项新技术应
用于他们的产品和服务。因此，这给RFID技术的研究带来了机遇和挑战。本文简单介绍了RFID系统的组成、原理及RFID技术的特点。本文比较了RFID 与传统条码，然后提供了一个简短的关于目前RFID应用情况的调查报告。 关键词：无线射频识别技术应用物流
一、简 介 无线射频识别（RFID ）是一种识别技术。与RFID 技术的前身——条码技术相比，RFID 技术具有很多的优点。但由于其成本高，RFID 技术至今未能广泛应用到各行各业。RFID 技术因其无需视线扫描而具有无可比拟的先进性，它能够降低劳动力水平，提高知名度并改善库存管理。 RFID 技术的普及提供了一项人或物体定位及追踪的解决方案。RFID 定位与跟踪系统根据独特的识别标签、阅读器与物体标签间射频通信的信号强度确定物体的空间位置，主要适用于室内，而GPS 系统是不适合应用于室内的。 RFID 技术是一项基于“无线电频率”的非接触式的自动识别技术，自动识别静态或动态的人和对象。 RFID 标签是一个特殊的微芯片，植入商品中，可以跟踪和管理物理对象，是物流管理信息化和跟踪信息化的重要手段。 RFID 的系统组成部分包括： (1）标签（应答器）：对象植入待确定。 (2）阅读器：可以读或读/写，按结构和技术。正如图1-1，RFID 的工作原理 图1-1 RFID 的工作原理 与计算机通讯 阅读器 电磁波（操作指 令和新的数据） 标签 发出的ID 代码和数据
Lathes Lathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool. The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod. The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed. The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives. Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle. The tailsticd assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw. The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers. Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances up
Cover封面 Content目录 Design Explanation设计说明 Master Plan总平面 Space Sequence Analysis景观空间分析 Function Analysis功能分析 Landscape Theme Analysis景观景点主题分析图 Traffic Analysis交通分析 Vertical Plan竖向平面布置图 Lighting Furniture Layout灯光平面布置示意图 Marker/Background Music/Garbage Bin标识牌/背景音乐/垃圾桶布置图Plan平面图 Hand Drawing手绘效果图 Section剖面图 Detail详图 Central Axis中心公共主轴 Reference Picture参考图片 Planting Reference Picture植物选样 材料类： aluminum铝 asphalt沥青 alpine rock轻质岗石 boasted ashlars粗凿 ceramic陶瓷、陶瓷制品 cobble小圆石、小鹅卵石 clay粘土 crushed gravel碎砾石 crushed stone concrete碎石混凝土 crushed stone碎石 cement石灰 enamel陶瓷、瓷釉 frosted glass磨砂玻璃 grit stone/sand stone砂岩 glazed colored glass/colored glazed glass彩釉玻璃 granite花岗石、花岗岩 gravel卵石 galleting碎石片 ground pavement material墙面地砖材料 light-gauge steel section/hollow steel section薄壁型钢 light slates轻质板岩 lime earth灰土 masonry砝石结构
伺服电机 1. 伺服电机的定义 伺服电动机又称执行电动机，在自动控制系统中，用作执行元件，把所收到的电信号转换成电动机轴上的角位移或角速度输出。分为直流和交流伺服电动机两大类，其主要特点是，当信号电压为零时无自转现象，转速随着转矩的增加而匀速下降。伺服电机在伺服系统中控制机械元件运转的发动机. 是一种补助马达间接变速装置。伺服电机可使控制速度, 位置精度非常准确。将电压信号转化为转矩和转速以驱动控制对象。转子转速受输入信号控制，并能快速反应，在自动控制系统中作执行元件，且具有机电时间常数小、线性度高、始动电压低等特点。 2. 伺服电机工作原理 1.伺服主要靠脉冲来定位，基本上可以这样理解，伺服电机接收到1 个脉冲，就会旋转1 个脉冲对应的角度，从而实现位移，因为，伺服电机本身具备发出脉冲的功能，所以伺服电机每旋转一个角度，都会发出对应数量的脉冲，这样，和伺服电机接受的脉冲形成了呼应，或者叫闭环，如此一来，系统就会知道发了多少脉冲给伺服电机，同时又收了多少脉冲回来，这样，就能够很精确的控制电机的转动，从而实现精确的定位，可以达到0.001mm有刷电机成本低，结构简单，启动转矩大，调速范围宽，控制容易，需要维护，但维护方便（换碳刷），产生电磁干扰，对环境有要求。无刷电机体积小，重量轻，出力大，响应快，速度高，惯量小，转动平滑，力矩稳定。控制复杂，容易实现智能化，其电子换相方式灵活，可以方波换相或正弦波换相。电机免维护，效率很高，运行温度低，电磁辐射很小，长寿命，可用于各种环境。 2. 交流伺服电机也是无刷电机，分为同步和异步电机，目前运动控制中一般都用同步电机，它的功率范围大，可以做到很大的功率。大惯量，最高转动速度低，且随着功率增大而快速降低。因而适合做低速平稳运行的应用。 3. 永磁交流伺服电动机简介 20 世纪80 年代以来，随着集成电路、电力电子技术和交流可变速驱动技术的发展，永磁交流伺服驱动技术有了突出的发展，各国著名电气厂商相继推出各自的交流伺服电动机和伺服驱动器系列产品并不断完善和更新。交流伺服系统已成为当代高性能伺服系统的主要发展方向，使原来的直流伺服面临被淘汰的危机。90 年代以后，世界各国已经商品化了的交流伺服系统是采用全数字控制的正弦
人工智能 【摘要】：人工智能是一门极富挑战性的科学，但也是一门边沿学科。它属于自然科学和社会科学的交叉。涉及的学科主要有哲学、认知科学、数学、神经生理学、心理学、计算机科学、信息论、控制论、不定性论、仿生学等。人工智能(Artificial Intelligence)，英文缩写为AI。它是研究、开发用于模拟、延伸和扩展人的智能的理论、方法、技术及应用系统的一门新的技术科学。人工智能是计算机科学的一个分支，它企图了解智能的实质，并生产出一种新的能以人类智能相似的方式做出反应的智能机器，该领域的研究包括机器人、语言识别、图像识别、自然语言处理和专家系统等1。 【关键词】：人工智能；应用领域；发展方向；人工检索。 1．人工智能描述 人工智能(Artificial Intelligence) ，英文缩写为AI。它是研究、开发用于模拟、延伸和扩展人的智能的理论、方法、技术及应用系统的一门新的技术科学2。人工智能是计 算机科学的一个分支，它企图了解智 能的实质，并生产出一种新的能以人 类智能相似的方式作出反应的智能 机器，该领域的研究包括机器人、语 言识别、图像识别、自然语言处理和 专家系统等。“人工智能”一词最初 是在1956 年Dartmouth学会上提出 的。从那以后,研究者们发展了众多 理论和原理,人工智能的概念也随之扩展。人工智能是一门极富挑战性的科学，从事这项工作的人必须懂得计算机知识，心理学和哲学。人工智能是包括十分广泛的科学，它由不同的领域组成，如机器学习，计算机视觉等等，总的说来，人工智能研究的一个主要目标是使机器能够胜任一些通常需要人类智能才能完成的复杂工作。但不同的时代、不同的人对这种“复杂工作”的理解是不同的。例如繁重的科学和工程计算本来是要人脑来承担的，现在计算机不但能完成这种计算, 而且能够比人脑做得更快、更准确，因之当代人已不再把这种计算看作是“需要人类智能才能完成的复 1.蔡自兴，徐光祐.人工智能及其应用.北京：清华大学出版社，2010 2元慧·议当人工智能的应用领域与发展状态〖Ｊ〗．2008