步進電機和伺服電機的系統(tǒng)控制——外文翻譯、英文翻譯

Step Motor& Servo Motor Systems and Controls Motion Architect Software Does the Work for You. Configure ,Diagnose, Debug Compumotors Motion Architect is a Microsoft Windows-based software development tool for 6000Series 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 ConfiguratorThis module prompts you to fill in all pertinent set-up information to initiate motion. Configurable to the specific 6000 Series product that is selected, the information is then used to generate actual 6000-language code that is the beginning of your program. Program EditorThis module allows you to edit code. It also has the commands available through “Help” menus. A users guide is provided on disk. Terminal EmulatorThis module allows you to interact directly with the 6000 product. “Help” is again available with all commands and their definitions available for reference. Test PanelYou can simulate your programs, debug programs, and check for program flow using this module. Motion Architect has been designed for use with all 6000 Series productsfor both servo and stepper technologies. The versatility of Windows and the 6000 Series language allow you to solve applications ranging from the very simple to the complex. Motion Architect comes standard with each of the 6000 Series products and is a tool that makes using these controllers even more simpleshortening the project development time considerably. A value-added feature of Motion Architect, when used with the 6000 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 Compumotor 6000 Series Software Reference Guide. SOLVING APPLICATIONS FROM SIMPLE TO COMPLEX Servo Control is Yours with Servo Tuner Software Compumotor combines the 6000 Series 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 real-time motion information and provide an easy environment for setting tuning gains and related systemparameters as well as providing file operations to save and recall tuning sessions. Draw Your Own Motion Control Solutions with Motion Toolbox Software Motion Toolbox is an extensive library of LabVIEW virtual instruments (VIs) for icon-based programming of Compumotors 6000 Series motion controllers. When using Motion Toolbox with LabVIEW, programming of the 6000 Series controller is accomplished by linking graphic icons, or VIs, together to form a block diagram. Motion Toolboxs has a library of more than 150 command,status, and example VIs. All command and status VIs include LabVIEW source diagrams so you can modify them, if necessary, to suit your particular needs. Motion Toolbox als user manual to help you gut up and running quickly. comprehensiveM Software for Computer-Aided Motion Applications CompuCAM is a Windows-based programming package that imports geometry from CAD programs, plotter files, or NC programs and generates 6000 code compatible with Compumotors 6000 Series motion controllers. Available for purchase from Compumotor, CompuCAM is an add-on module which is invoked as a utility from the menu bar of Motion Architect. From CompuCAM, run your CAD software package. Once a drawing is created, save it as either a DXF file, HP-GL plot file or G-code NC program. This geometry is then imported into CompuCAM where the 6000 code is generated. After generating the program, you may use Motion Architect functions such as editing or downloading the code for execution. Motion Builder Software for Easy Programming of the 6000 Series Motion Builder revolutionizes motion control programming. This innovative software allows programmers to program in a way they are familiar witha flowchart-style method. Motion Builder decreases the learning curve and makes motion control programming easy. Motion Builder is a Microsoft Windows-based graphical development environment which allows expert and novice programmers to easily program the 6000 Series products without learning a new programming language. Simply drag and drop visual icons that represent the motion functions you want to perform. Motion Builder is a complete application development environment. In addition to visually programming the 6000 Series products, users may configure, debug, download, and execute the motion program. SERVO VERSUS STEPPER. WHAT YOU NEED TO KNOW Motor Types and Their Applications The following section will give you some idea of the applications that are particularly appropriate for each motor type, together with certain applications that are best avoided. It should be stressed that there is a wide range of applications which can be equally well met by more than one motor type, and the choice will tend to be dictated by customer preference, previous experience or compatibility with existing equipment. A helpful tool for selecting the proper motor for your application is Compumotors Motor Sizing and Selection software package. Using this software, users can easily identify the appropriate motor size and type. High torque, low speed continuous duty applications are appropriate to the step motor. At low speeds it is very efficient in terms of torque output relative to both size and input power. Microstepping can be used to improve smoothness in lowspeed applications such as a metering pump drive for very accurate flow control. High torque, high speed continuous duty applications suit the servo motor, and in fact a step motor should be avoided in such applications because the high-speed losses can cause excessive motor heating. Short, rapid, repetitive moves are the natural domain of the stepper due to its high torque at low speeds, good torque-to-inertia ratio and lack of commutation problems. The brushes of the DC motor can limit its potential for frequent starts, stops and direction changes. Low speed, high smoothness applications are appropriate for microstepping or direct drive servos. Applications in hazardous environments or in a vacuum may not be able to use a brushed motor. Either a stepper or a brushless motor is called for, depending on the demands of the load. Bear in mind that heat dissipation may be a problem in a vacuum when the loads are excessive. SELECTING THE MOTOR THAT SUITS YOUR APPLICATION Introduction Motion control, in its widest sense, could relate to anything from a welding robot to the hydraulic system in a mobile crane. In the field of Electronic Motion Control, we are primarily concerned with systems falling within a limited power range, typically up to about 10HP (7KW), and requiring precision in one or more aspects. This may involve accurate control of distance or speed, very often both, and sometimes other parameters such as torque or acceleration rate. In the case of the two examples given, the welding robot requires precise control of both speed and distance； the crane hydraulic system uses the driver as the feedback system so its accuracy varies with the skill of the operator. This wouldnt be considered a motion control system in the strict sense of the term.Our standard motion control system consists of three basic elements: Fig. 1 Elements of motion control system The motor. This may be a stepper motor (either rotary or linear), a DC brush motor or a brushless servo motor. The motor needs to be fitted with some kind of feedback device unless it is a stepper motor. Fig. 2 shows a system complete with feedback to control motor speed. Such a system is known as a closed-loop velocity servo system. Fig. 2 Typical closed loop (velocity) servo system The drive. This is an electronic power amplifier thatdelivers the power to operate the motor in response to low-level control signals. In general, the drive will be specifically designed to operate with a particular motor type you cant use a stepper drive to operate a DC brush motor, for instance. Application Areas of Motor Types Stepper Motors Stepper Motor Benefits Stepper motors have the following benefits: Low cost Ruggedness Simplicity in construction High reliability No maintenance Wide acceptance No tweaking to stabilize No feedback components are needed They work in just about any environment Inherently more failsafe than servo motors. There is virtually no conceivable failure within the stepper drive module that could cause the motor to run away. Stepper motors are simple to drive and control in an open-loop configuration. They only require four leads. They provide excellent torque at low speeds, up to 5 times the continuous torque of a brush motor of the same frame size or double the torque of the equivalent brushless motor. This often eliminates the need for a gearbox. A stepper-driven-system is inherently stiff, with known limits to the dynamic position error. Stepper Motor Disadvantages Stepper motors have the following disadvantages: Resonance effects and relatively long settling times Rough performance at low speed unless a microstep drive is used Liability to undetected position loss as a result of operating open-loop They consume current regardless of load conditions and therefore tend to run hot Losses at speed are relatively high and can cause excessive heating, and they are frequently noisy (especially at high speeds). They can exhibit lag-lead oscillation, which is difficult to damp. There is a limit to their available size, and positioning accuracy relies on the mechanics (e.g., ballscrew accuracy). Many of these drawbacks can be overcome by the use of a closed-loop control scheme. Note: The Compumotor Zeta Series minimizes or reduces many of these different stepper motor disadvantages. There are three main stepper motor types: Permanent Magnet (P.M.) Motors Variable Reluctance (V.R.) Motors Hybrid Motors When the motor is driven in its full-step mode, energizing two windings or “phases” at a time (see Fig. 1.8), the torque available on each step will be the same (subject to very small variations in the motor and drive characteristics). In the half-step mode, we are alternately energizing two phases and then only one as shown in Fig. 1.9. Assuming the drive delivers the same winding current in each case, this will cause greater torque to be produced when there are two windings energized. In other words, alternate steps will be strong and weak. This does not represent a major deterrent to motor performancethe available torque is obviously limited by the weaker step, but there will be a significant improvement in low-speed smoothness over the full-step mode. Clearly, we would like to produce approximately equal torque on every step, and this torque should be at the level of the stronger step. We can achieve this by using a higher current level when there is only one winding energized. This does not over dissipate the motor because the manufacturers current rating assumes two phases to be energized the current rating is based on the allowable case temperature). With only one phase energized, the same total power will be dissipated if the current is increased by 40%. Using this higher current in the one-phase-on state produces approximately equal torque on alternate steps (see Fig. 1.10). Fig. 1.8 Full step current, 2-phase on Fig. 1.9 Half step current Fig. 1.10 Half step current, profiled We have seen that energizing both phases with equal currents produces an intermediate step position half-way between the one-phase-on positions. If the two phase currents are unequal, the rotor position will be shifted towards the stronger pole. This effect is utilized in the microstepping drive, which subdivides the basic motor step by proportioning the current in the two windings. In this way, the step size is reduced and the low-speed smoothness is dramatically improved. High-resolution microstep drives divide the full motor step into as many as 500 microsteps, giving 100,000 steps per revolution. In this situation, the current pattern in the windings closely resembles two sine waves with a 90 phase shift between them (see Fig. 1.11). The motor is now being driven very much as though it is a conventional AC synchronous motor. In fact, the stepper motor can be driven in this way from a 60 Hz-US (50Hz-Europe) sine wave source by including a capacitor in series with one phase. It will rotate at 72 rpm. Fig. 1.11 Phase currents in microstep mode Standard 200-Step Hybrid Motor The standard stepper motor operates in the same way as our simple model, but has a greater number of teeth on the rotor and stator, giving a smaller basic step size. The rotor is in two sections as before, but has 50 teeth on each section. The half-tooth displacement between the two sections is retained. The stator has 8 poles each with 5 teeth, making a total of 40 teeth (see Fig. 1.12). Fig. 1.12 200-step hybrid motor If we imagine that a tooth is placed in each of the gaps between the stator poles, there would be a total of 48 teeth, two less than the number of rotor teeth. So if rotor and stator teeth are aligned at 12 oclock, they will also be aligned at 6 oclock. At 3 oclock and 9 oclock the teeth will be misaligned. However, due to the displacement between the sets of rotor teeth, alignment will occur at 3 oclock and 9 oclock at the other end of the rotor. The windings are arranged in sets of four, and wound such that diametrically-opposite poles are the same. So referring to Fig. 1.12, the north poles at 12 and 6 oclock attract the south-pole teeth at the front of the rotor； the south poles at 3 and 9 oclock attract the north-pole teeth at the back. By switching current to the second set of coils, the stator field pattern rotates through 45. However, to align with this new field, the rotor only has to turn through 1.8. This is equivalent to one quarter of a tooth pitch on the rotor, giving 200 full steps per revolution. Note that there are as many detent positions as there are full steps per rev, normally 200. The detent positions correspond with rotor teeth being fully aligned with stator teeth. When power is applied to a stepper drive, it is usual for it to energize in the “zero phase” state in which there is current in both sets of windings. The resulting rotor position does not correspond with a natural detent position, so an unloaded motor will always move by at least one half step at power-on. Of course, if the system was turned off other than in the zero phase state, or the motor is moved in the meantime, a greater movement may be seen at power-up. Another point to remember is that for a given current pattern in the windings, there are as many stable positions as there are rotor teeth (50 for a 200-step motor). If a motor is de-synchronized, the resulting positional error will always be a whole number of rotor teeth or a multiple of 7.2. A motor cannot “miss” individual steps position errors of one or two steps must be due to noise, spurious step pulses or a controller fault. Fig. 2.19 Digital servo drive Digital Servo Drive Operation Fig. 2.19 shows the components of a digital drive for a servo motor. All the main control functions are carried out by the microprocessor, which drives a D-to-A convertor to produce an analog torque demand signal. From this point on, the drive is very much like an analog servo amplifier. Feedback information is derived from an encoder attached to the motor shaft. The encoder generates a pulse stream from which the processor can determine the distance travelled, and by calculating the pulse frequency it is possible to measure velocity. The digital drive performs the same operations as its analog counterpart, but does so by solving a series of equations. The microprocessor is programmed with a mathematical model (or “algorithm”) of the equivalent analog system. This model predicts the behavior of the system. In response to a given input demand and output position. It also takes into account additional information like the output velocity, the rate of change of the input and the various tuning settings. To solve all the equations takes a finite amount of time, even with a fast processor this time is typically between 100ms and 2ms. During this time, the torque demand must remain constant at its previously-calculated value and there will be no response to a change at the input or output. This “update time” therefore becomes a critical factor in the performance of a digital servo and in a high-performance system it must be kept to a minimum. The tuning of a digital servo is performed either by pushbuttons or by sending numerical data from a computer or terminal. No potentiometer adjustments are involved. The tuning data is used to set various coefficients in the servo algorithm and hence determines the behavior of the system. Even if the tuning is carried out using pushbuttons, the final values can be uploaded to a terminal to allow easy repetition. In some applications, the load inertia varies between wide limits think of an arm robot that starts off unloaded and later carries a heavy load at full extension. The change in inertia may well be a factor of 20 or more, and such a change requires that the drive is re-tuned to maintain stable performance. This is simply achieved by sending the new tuning values at the appropriate point in the operating cycle. 步進電機和伺服電機的系統(tǒng)控制 運動的控制者 -軟件：只要有了軟件，它可以幫助我們配置改裝、診斷故障、調(diào)試程序等。數(shù)控電動機的設(shè)計者會是一個微軟窗口 基于構(gòu)件的軟件開發(fā)工具，可以為 6000 系列產(chǎn)品設(shè)置代碼，同時可以控制設(shè)計者與執(zhí)行者的運動節(jié)目，并創(chuàng)造一個定制運 營商的測試小組。運動建筑師的心臟是一個空殼，它可以為進入以下模塊提供一個綜合環(huán)境。 1. 系統(tǒng)配置 這個 模塊提示您填寫所有相關(guān)初成立信息啟動議案。配置向具體6000 系列產(chǎn)品的選擇，然后 這些信息將 用于產(chǎn)生實際 的 6000 - 語言代碼，這是你的 開始 計劃。 2. 程序編輯器 允許你編輯代碼。它也有 可行的“幫助”命令菜單。 A 用戶指南提供了相關(guān)的磁盤指南。 3. 終端模擬器 本模塊，可讓您 直接與 6000 系列產(chǎn)品互動。他所提供的“幫助”是再次參考所有命令和定義。 4. 測試小組 你可以使用本模塊，模擬程序，調(diào)試程序，并跟蹤檢測程序 。 運動建筑師已經(jīng)將所有的 6000 系列產(chǎn)品都運用在了步進電機和伺服電機的技術(shù)上。由于豐富的對話窗口和 6000 系列語言，使得你能夠從簡單到復(fù)雜的解決問題。 運動建筑師的 6000 系列產(chǎn)品的標(biāo)準(zhǔn)配置工具，能夠使得這些控制器更加簡單，相當(dāng)大的縮短項目開發(fā)時間。它的另外一個增值特點是使用 6000 伺服控制器的調(diào)諧助手。基于調(diào)諧價值觀，這個額外的模塊可以以圖形化的方式為你展示各種參數(shù)。看看這些參數(shù)是如何讓變化的。用 運動的建筑師，你可以 一次性 打開多個窗口。舉例來說，無論是程序編輯器和終端模擬器窗口， 你都可以 打開運行程序， 得到信息，然后改變 這一程序 。 運動建筑師可以利用在線幫助，在整個互動接觸內(nèi)容中為數(shù)控電機 6000 系列軟件做參考指南。 從簡單到復(fù)雜的解決應(yīng)用 伺服控制是你 用 伺服調(diào)諧器軟件 控制。數(shù)控電機與 6000 系列伺服控制器相結(jié)合并應(yīng)用 伺服調(diào)諧器軟件 。 伺服調(diào)諧器是一個新增功能模塊 ，它 擴展和提高 運動 建筑師 的能力。 議案建筑師與伺服調(diào)諧器結(jié)合起來，以提供圖形化的反饋 方式，反饋 實時運動信息并提供簡便環(huán)境設(shè)置微調(diào)收益及相關(guān)制參數(shù)以及提供文件操作，以保存并記得微調(diào)會議。 請你用運動工具箱軟件解決自己的運動控制。運動工具箱實際上是一個為數(shù) 控電機和 6000 系列運動控制器而設(shè)計的廣泛應(yīng)用的虛擬圖標(biāo)式編程儀器。 當(dāng)使用 運動 工具箱與 虛擬編程儀時， 編程 6000 系列控制器 實質(zhì)上是 完成連接圖形圖標(biāo)，或加上形成框圖 使之可見 。 運動 工具箱中 包含了 1500 多 條命令 ， 狀態(tài)欄 ，實例等 。所有 的命令、狀態(tài)欄、實例都 包括 可視 的來源圖表，使您可以修改他們，如果有必要， 可以 滿足您的特殊的需要。 運動 工具箱同時還具有一個 可 視 窗口， 基于安裝程序和一個全面的用戶手冊， 可 以幫助您運行得更好更快。 軟 件 電腦輔助 運動應(yīng)用軟件 compucam compucam是 基于微軟的 編程 包，它能從 CAD程序 、示波器文檔、 數(shù)控程序和產(chǎn)生6000 系列數(shù)控電機密碼相 兼容 的運動控制器中輸入幾何圖形。 購買 數(shù)控電機是可行的 ， 因為 compucam 是一個附加模塊，是 運動建筑師的菜單欄，它是作為 公用 部分而被引用的。程序 從 compucam 開始 運行 CAD 軟件包。一旦 程序被起草創(chuàng)作 ， 它就會被 保存為 DXF 文件， 或 惠普 -吉爾 段文檔， 或 G 代碼數(shù)控 程序 。這 些 幾 何圖形 然后輸入 compucam中，產(chǎn)生 6000 系列代碼。在程序運行之后 ，你可使用的 運動 建筑師功能 塊 ，如編輯或下載代碼 等執(zhí)行程序。 運動執(zhí)行 者軟件 可 輕松編程 6000 系列 運動執(zhí)行 者 革命性 控制 運動編程 。 這一具有創(chuàng)新意義的軟件允 許 程序員 以 他們所熟悉的 - 流程圖式的方法 編程 。 運動執(zhí)行者 降低 了 學(xué)習(xí)曲線，并 使 運動控制編程變得相當(dāng)容易 。 運動執(zhí)行者 是一套微軟 軟件， 基于 圖形化窗口的發(fā)展， 讓專家和新手程序員容易 學(xué)習(xí) 計劃 6000 系列產(chǎn)品新的編程語言。 簡單地拖放 代表議案職能的視覺圖標(biāo)，你 可以隨時的進行你所需要的操作 。 運動執(zhí)行者是 一個完整的應(yīng)用開發(fā)環(huán)境 的軟件 。除了視覺編程 6000 系列產(chǎn)品，用戶 還 可 以 配置，調(diào)試，下載， 策劃和執(zhí)行的議案計劃。 電機類型及其 應(yīng)用 下一節(jié)將會給你介紹一些的適用特別場合的電 機，而某些應(yīng)用是最好避免。應(yīng)當(dāng)強調(diào)說，在一個廣范的應(yīng)用范圍，電機是可同樣滿足一個以上的汽車類型， 而選擇往往是由客戶偏好、以往經(jīng)驗或與現(xiàn)有的設(shè)備的兼容性決定的。一個非常有用的工具箱，可供你選擇適當(dāng)?shù)倪\動，為你選擇電機與選擇軟件包是 compumotor 軟件包。使用這個軟件，使用戶可以輕松找出適當(dāng)?shù)碾姍C大小和類型。 高扭矩，低 轉(zhuǎn) 速 連續(xù) 脈沖 適宜 于步進電機時， 在低速時， 就相對于 扭矩輸出規(guī)模和輸入功率 而言， 它是非常高效率。 微步，在低速應(yīng)用，可以用來提高平滑度 。 如 可 作為計量泵驅(qū)動非常精確的流量控制。 高扭矩，高 轉(zhuǎn) 速 連續(xù) 脈沖 適應(yīng) 于 伺服電機 時 ，其實步進電機應(yīng)避免 使用 在 這種情況下。這是因為高速 可導(dǎo)致 負荷。 簡捷 ，快速，重復(fù)性動作 僅是自然域的步進 電機 由于其在低速時高轉(zhuǎn)矩， 因而存在 慣性比例 大， 及缺乏折算的問題。直流電動機 的電刷 可限制其潛 在的 頻繁開始，停止和方向 的改變。 低速 ， 高光滑 的應(yīng)用 這 是最 適合于 微步或直接驅(qū)動伺服 電機。 適用于 危險環(huán)境或在真空中可能不能夠使用 電刷電機 。步進或無刷 電機是無所謂的 ，靠的 是對 負荷 的需求。 牢記當(dāng)負載過高 時， 熱耗散可能是個問題 。 選擇適合你的電機 導(dǎo)言 運動控制，在其最廣泛的意義上說，可能與 任何移動式起重機 中 焊接機器人液壓系統(tǒng) 有關(guān) 。在電子運動控制領(lǐng)域，我們的主要關(guān)切系統(tǒng)范圍內(nèi)的有限 功率的大小 ， 通常高達約 10hp （ 7 千瓦），并要求在一個或多個方面 有嚴(yán)格 精密。這可能涉及精確控制的距離或速度，但很多時候 是 雙方的，有時 還涉及 其它參數(shù)如轉(zhuǎn)矩或加速率。在 以下 所舉的 兩個 例子 中 ，焊接機器人，需要精確 的 控制 雙方 的速度和距離 ；吊臂液壓系統(tǒng)采用 驅(qū)動 作為反饋系統(tǒng) ， 因此，它的準(zhǔn)確度會隨 著操作者的 技能的不同而不同 。在嚴(yán)格意義上來說 ， 這將不會被視為一項 運動 控制系統(tǒng)。 我們的標(biāo)準(zhǔn)運動控制系統(tǒng) 由以下 三個基本要素組成： 圖 1 運動控制系統(tǒng) 的組成 元件 高級命令 命令信號 混合式步進直流 伺服無刷電機 電機， 可能是一個步進電機（要么旋轉(zhuǎn)或線性） ，也可能是 直流無刷電機或無刷伺服馬達。 電機 必須配備一些種回饋裝置，除非它是一個步進 電機 。 圖 2 顯示了一個完善 地 反饋控制電機轉(zhuǎn)速 的系統(tǒng) 。這樣一個 具有 閉環(huán) 控制 系統(tǒng)的速度伺服系統(tǒng)。 圖 2 典型的閉環(huán)（ 速度）伺服系統(tǒng) 轉(zhuǎn)速表 電壓反饋 驅(qū)動器是一個電子功率放大器 ，以 提供電力操作電動機 來 回應(yīng)低層次的控制信號。一般來說，驅(qū)動器將特別設(shè)計， 其 操作與特定電機類型 相配合。例如， 你不能用一個步進驅(qū)動器 來操作 直流無刷電機。 不同電機適應(yīng)的不同領(lǐng)域 步進電機 ： 步進電機的好處 。 步進電機有以下好處： （ 1） 成本低廉 （ 2） 堅固耐用 （ 3）結(jié)構(gòu) 簡單 （ 4） 高可靠 性 （ 5） 無維修 （ 6）適用 廣泛 （ 7） 穩(wěn)定 性很高（ 8） 無 需 反饋元件 （ 8）適應(yīng)多種 工作環(huán)境 （ 9）相對伺服電機更具有保險性 。 驅(qū)動器 電機 控制器 主計算機 或 PLC 控制器 /索引 驅(qū)動 電機 因此，幾乎沒有任何可以想象的失敗 使 步進驅(qū)動模塊 出錯 。步進電機 驅(qū)動 簡單 ，并且驅(qū)動和 控制在一個開放的閉環(huán) 系統(tǒng)內(nèi) 。他們只需要 4 個 驅(qū)動器 。低速時 ，驅(qū)動器 提供良好的扭矩， 是有 刷電機同一幀大小 5 倍連續(xù)力 距， 或相當(dāng)于無刷電機一倍扭矩。這往往不再需要變速箱。步進驅(qū)動 系統(tǒng)遲緩 ， 在限定的范圍內(nèi)，可以更好的減少 動態(tài)位置誤差 。 步進電機弊端 。 步進電機有下列缺點： （ 1） 共振效應(yīng)和相對長 的適應(yīng)性（ 2） 在低速 ， 表現(xiàn)粗 糙，除非微驅(qū)動器 來驅(qū)動（ 3）開環(huán)系統(tǒng)可能導(dǎo)致未被查覺的損失（ 4）由于過載， 他們消耗 過多 電流 。 因此傾向于 過熱運行。（ 5） 虧損速度比較高，并可產(chǎn)生過 多熱量因此 ，他們 噪音很大（尤其是在高速下） 。（ 6） 他們 的 滯后 現(xiàn)象 導(dǎo)致振蕩，這是很難 抑制的 。 對他們的可行性，這兒有 一個限度， 而 他們 的 大小，定位精度 主要 依靠的是 機器 （例如，滾珠絲杠的精確度） 。許多這些缺點是可以克服 的，通過 使用一個閉環(huán)控制方案。 注： compumotor 系列 能 很多 的 減小或降低了這些不同的步進電機不利之處。 主要有 3 類 步進電機： （ 1） 永磁 式步進電機 ，（ 2） 可變磁阻 式步進 電動機 ，（ 3）混合式步進電機