线性执行器运动系统术语表（中英文）

（绝对）精度 – 理想位置与实际位置之间的差异。

绝对定位 – 指采用位置反馈装置来保持给定机械位置的运动控制系统。

ACME 丝杠 – 机器应用中最常见的丝杠类型。 ACME 螺纹是一种特殊类型的螺纹。与滚珠丝杠相比， ACME 丝杠具有非常高的摩擦力和反冲力，这两者都不适合高性能应用。

交流电机 – 一种使用交流电运行的电动机。交流电机在工业中比直流电机更常用，但在低速下运行不佳。

精度 – 某物与其绝对值或完美值相比的相对状态。在运动控制中，这通常是位置描述。例如，命令可以设置为 4.0 英寸。系统的精度将根据系统对移动的影响接近 4.0 英寸的绝对值来定义。准确度可以定义为一次性事件或多个周期或运动的平均值。定位精度通常用偏差（与理论值的 +/-）或极限（与理论值的可接受偏差）来定义：即 3.8 - 4.3 英寸定义理论点周围可接受的偏差极限。

实际位置 – 轴相对于指令位置的位置。这可能是指令移动结束时的位置，或移动过程中任何一点的指令位置与该点轴的实际位置之间的滞后。后者通常称为跟随误差。

弧分 – 等于 1/60 度的角度测量。

运动轴：受控运动发生的特定主要方向。通常指特定机器中采用的这些主要方向的数量。通常定义如下：

X：定位方向上的线性运动

Y：垂直于定位方向的线性运动

Z：垂直线性运动

A：绕 X 的角运动（滚动）

B：绕 Y 的角运动（俯仰）

C：绕 Z 的角运动（偏航）

轴向载荷– 轴承的术语“轴向载荷”和“径向载荷”：轴向载荷是与轴承旋转轴平行的任何载荷。径向载荷是与旋转轴垂直的任何载荷。

轴向游隙 – 由于轴向力的反转而导致的轴的轴向位移。

轴 – 工具、部件或工件移动的主要方向。控制机器中每个自由度的部件可视为轴。X-Y-Z 机器是一种三轴机器，其中 X 轴和 Y 轴控制水平面的运动，Z 轴控制上下运动。每个轴可以由控制器、驱动器、电机和传输组件组成，这些组件是耦合到负载所必需的。

轴 – 轴的复数。

间隙 – 由机械部件之间的松散连接引起的间隙。当轴改变方向时，间隙会成为一个问题。当电机转动时，它会将所有齿轮推向一个方向。当电机反转时，齿轮齿从一侧分离，在另一侧相遇。分离的距离就是齿隙。

滚珠丝杠 – 滚珠丝杠是一种高效、低摩擦、低齿隙的导螺杆装置，使用滚珠轴承在丝杠切入的通道中滚动。低摩擦和齿隙属性对于用于驱动机器轴的精密应用极其有价值。

无刷电机 – 无刷电机是一类使用相电流电子换向而不是机电（电刷型）换向来运行的电机。无刷电机通常具有永磁转子和绕线定子。

圆弧插补 – 通过两个轴的协调运动产生明显的圆弧运动。实际路径是一系列由软件算法生成的直线近似值。

碰撞检测 – 使用传感器检测运动控制系统中两个或多个部件即将发生的碰撞。检测传感器的信号可用于停止运动或提供逐渐减速以实现接近部件的“软”配合。

协调 – 两个或多个运动轴的运动的整合，因此产生的运动是任何轴都无法独立完成的路径。协调还可能涉及在整合工作中使用传感器和其他内部或外部命令，以帮助实现所需的运动或工作。

耦合（耦合器、耦合器） – 通过它们之间的互电容将能量从一个电路传输到另一个电路。在反馈和控制系统中，这被认为是电噪声，是一个常见问题。

按长度切割 – 运动控制过程或独立过程的子程序，其中进料材料以预设距离进行处理。距离在执行任务和/或次要任务（例如切断进料材料）之前设置。采用反馈系统来确保预设进料长度的可重复性。

制动扭矩 – 制动扭矩是电机中无电流流动时的保持扭矩。可施加到未通电步进电机轴上而不导致连续旋转的最大扭矩。未通电电机中存在的最小扭矩。步进电机的制动扭矩通常约为其静态通电扭矩的 1%。

动态扭矩 – 电机在低速步进时产生的扭矩。

效率 – 物理学中：有效的能量使用、每单位能量的有用功或相对于理想机械优势的机械优势，通常用希腊小写字母 η (Eta) 表示。在热力学中：效率是能量转换效率，是第二定律热力学损失的量度。热效率：燃料高热值下的有用功。在计算中：算法效率是优化计算机程序的速度和内存需求，而存储效率是计算机数据存储的有效性。

电子离合器 – 通过启用和禁用电子凸轮或齿轮传动功能，根据主位置或时间段生成从属配置文件的过程。

电子齿轮传动 – 一种通过可变比率将一个闭环轴与第二个轴（开环或闭环）电同步来刺激机械齿轮的方法。

电子线轴 – 用作机器上的主轴的虚拟轴，其他轴通过电子齿轮传动或凸轮轮廓与该轴同步。

编码器 – 编码器是一种反馈设备。它由圆盘、叶片或反射器组成，通常连接到电机轴以提供数字脉冲，这些脉冲提供给转换器和/或计数器。如果输入到计数器中，这将提供位置信息。如果测量并解码连续脉冲之间的时间，则可以得出速度信息。

编码器分辨率 – 输入轴旋转 360 度时出现的电气识别位置数。

事件 – 输入参数的状态变化，例如限位开关或接近传感器的触发。

故障 – 驱动器或控制器尝试非法过程并被禁用时收到的错误。

反馈 – 反馈是被控制参数的测量值。为了使定位系统准确补偿误差，必须知道相对于命令位置的实际位置。在这种情况下，位置反馈将用于提供实际位置。

反馈信号 – 传感器在过程发生时检测到的实际值。反馈信号是闭环控制系统的一部分。

前馈 – 一种“预补偿”控制回路已知误差的方法，这些误差是由于电机、驱动器或负载特性引起的，以改善响应。它仅取决于命令，而不取决于测量的误差。

龙门架 – 一种设计用于沿 X、Y 和/或 Z 轴线性移动的架空框架。框架中通常设计有工具或其他设备，以便在从一个位置移动到另一个位置时执行各种功能。

变速箱 – 一种齿轮系统，将机械动力从原动机（例如电动机）传输到通常具有较低动量但较高扭矩的旋转输出设备。

保持扭矩 – 保持扭矩是当电动机的一个或多个相通电时，可以外部施加到电动机轴上而不会导致连续旋转的最大扭矩。

原点位置 – 所有绝对定位运动的参考位置。通常由原点限位开关和/或编码器标记定义。通常在通电时设置

归位 – 在通电时定位唯一的参考位置以进行轴校准。

索引器 – 在基于步进电机的系统中，索引器是一种向步进电机驱动器提供步进和方向控制信号的设备。更复杂的专用步进电机控制器还将具有 I/O 点和各种其他更高级的功能以及与 PLC 类似的可编程性。在许多情况下，PLC 可用作索引器。

索引 - 以定义的速度和加速度/减速度移动到预编程位置的一个或多个轴。

插补 - 两个或多个轴以线性和/或圆周运动协调移动。

点动 - 以固定速度和加速度/减速度在选定方向上运行的轴，没有特定的目的地。

导程 - 丝杠上螺母在丝杠旋转一圈期间行进的线性距离，例如英寸/转

丝杠 - 将旋转运动转换为线性运动的装置。

限制 – 运动系统内的传感器，用于提醒控制电子设备已接近行程的物理终点，并且不允许在特定方向上运动。

线性执行器 – 线性执行器是一种产生直线运动的执行器，与传统电动机的旋转运动形成对比。线性执行器用于机床和工业机械、计算机外围设备（如磁盘驱动器和打印机）、阀门和阻尼器以及许多其他需要线性运动的地方。液压缸或气动缸本身会产生线性运动；许多其他机制用于从旋转电机提供线性运动。

线性伺服电机 – 线性伺服电机是一种“扁平”伺服电机，转子位于内部，线圈位于可移动 U 形通道的外部。

线性滑轨 – 线性滑轨是精密产品，旨在将运动或扭矩转化为直线运动。线性滑轨旨在沿给定轴移动安装的机构。完整的滑轨通常至少由一个底座、一个鞍座、一个调节螺钉和一个直楔组成。

负载 – 施加到电机上的任何外部运动阻力（静态或动态）。

轴上精度 – 补偿线性误差后理想位置与实际位置之间的差异。线性误差包括：余弦误差、螺钉或线性刻度螺距不准确、测量点的角度偏差（阿贝误差）和热膨胀效应。绝对精度和轴上精度之间的关系如下：

绝对精度 = 轴上精度 + 校正系数 x 行程

超控 – 在故障情况下强制轴移动；通常需要强制轴脱离超程限位开关。

相位调整 – 在同步或电子线轴传动期间调整一个轴相对于其他轴的位置。这通常在轴移动时完成，并用于纠正小的配准问题。

拾取和放置 – 将物体从一个地方转移到另一个地方的应用，例如药丸分拣机、医用小瓶（试管）测试或空气样本测试仪。

螺距 – 螺钉一个螺纹上的任何一点到下一个连续螺纹上相应点的距离，例如转/英寸。

定位 – 通过提供目标位置、速度和加速度来指定移动。目标位置可以是绝对位置，也可以是相对于当前位置的相对位置。

位置控制 – 一种设计用于将物体或机器移动到已知位置的控制系统。例如：步进电机用于位置控制。

位置环 – 位置环通过连续比较目标位置和当前位置来运行。两者之间的差异是位置误差或跟随误差。

额定速度 – 制造商指定的电机产生最大额定功率的速度

额定扭矩 – 额定扭矩是电机在给定速度下的扭矩产生能力。这通常用扭矩/速度曲线来指定。

伺服机构 – 伺服机构可能使用也可能不使用伺服电机。例如，家用炉子就是由恒温器控制的伺服机构。一旦达到设定温度，反馈信号就会使系统关闭，从而使其本质上成为“伺服”。术语“伺服”更多地描述了一种功能或任务，而不是特定的产品线。伺服机构的定义特征是使用反馈，从而创建闭环系统。

伺服电机 – 伺服电机是伺服机构的一部分。它通常与某种类型的编码器配对，以提供定位和速度反馈。伺服电机是一种使用纠错程序来控制其运动的自动装置。术语伺服可以应用于伺服电机以外的系统；使用反馈机制（例如编码器或其他反馈设备）来控制运动参数的系统。通常，当使用术语伺服时，它适用于“伺服电机”，但也用作一般控制术语，这意味着使用反馈回路来定位物品。伺服电机可以是直流电机、交流电机或无刷直流电机，并结合位置传感器（大多数情况下是数字编码器）。伺服电机的定义特征是它在闭环系统中运行（使用反馈）。

屏蔽电缆 - 一种电缆，其导体周围有一层公共导电层，旨在提供电磁屏蔽，从而防止 EMI 问题

步进电机 – 步进电机（也称为步进或步进马达）是一种通过转换电脉冲实现机械运动的机电设备。步进电机由数字脉冲驱动，而不是由连续施加的电压驱动。与连续旋转的传统电动机不同，步进电机以固定的角度增量旋转或步进。步进电机最常用于位置控制。在步进电机/驱动器/控制器系统设计中，假设步进电机将遵循数字指令。步进电机的一个重要方面是缺乏反馈来保持位置控制，这使步进电机被归类为开环系统。步进电机可以正向或反向旋转，但不能移动大负载。

步进 – 步进是步进电机转子从一个通电位置移动到下一个通电位置的运动。

步进角 – 步进角是步进电机轴在相邻步进位置之间转动的标称角度。步进角取决于电机和驱动顺序（驱动模式）。步进角越小，分辨率越高。

步进增量 – 步进增量是步进或运动大小的指示。通常，旋转电机以度为单位，线性电机以英寸或毫米为单位。

步进 (步进、步进) 电机 – 步进与步进和步进电机同义：一种数字执行器，通过离散脉冲（输入信号）运行，以离散增量产生运动，可以是旋转的，也可以是线性的。请参阅上面的步进电机定义。

步进位置 – 空载步进电机轴通电时所处的角位置。步进位置不一定与制动位置相同。

扭矩 – 旋转力。扭矩以 N*m、lb*in、lb*ft 等为单位。1 N*m 是 1N 力施加到 1m 长的杠杆臂上产生的扭矩。

扭矩限制器 – 扭矩限制器是一种机械保护装置，当发生过载时，它会使负载与驱动器分离

偏航、俯仰 – 托架在移动时绕 Z 轴（偏航）或 Y 轴（俯仰）旋转。使用测试设备在空调室（20 °C±1 °C）内系统地测试轴上精度、重复性和反向误差。一个线性循环，行程上有 21 个数据点，每个方向有 4 个循环，总共有 164 个点。

(Absolute) Accuracy – Difference between ideal position and real position.

Absolute Positioning – Refers to a motion control system employing position feedback devices to maintain a given mechanical location.

ACME Screw – The most common type of lead screw found in machine applications. The ACME thread is a particular type of thread. Compared to a ball screw, ACME lead screws have a very high friction and backlash, both of which are undesirable for high-performance applications.

AC Motor – A type of electric motor that runs on alternating current. AC motors are more commonly used in industry than DC motors, but do not operate well at low speeds.

Accuracy – The relative status of something compared to its absolute or perfect value. In motion control this will most often be a position description. For example, a command may be set to 4.0 inches. The accuracy of the system will be defined on how close to the absolute value of 4.0 inches the system can affect the move. Accuracy may be defined as a one-time incident or the average over a number of cycles or motions. Positioning accuracy will normally be defined in terms of deviation (+/- from the theoretical) or limits (acceptable variation from the theoretical: i.e. 3.8 - 4.3 inches define acceptable limits of variation around a theoretical point.

Actual Position – The position of an axis relative to the commanded position. This may be the position at the end of the command move, or the lag between command position at any point during the move and the actual position of the axis at that point. The latter is commonly referred to as following error.

ARC Minute – An angular measurement equal to 1/60th of a degree.

Axes of Motion: The specific major directions along which controlled movement occurs. Usually referred to as the number of these major directions employed in a specific machine. Generally defined as follows:

X: Linear motion in a positioning direction

Y: Linear motion perpendicular to the positioning direction

Z: Vertical linear movement

A: Angular motion around X (roll)

B: Angular motion around Y (pitch)

C: Angular motion around Z (yaw)

Axial Load – The terms 'axial load' and 'radial load' with respect to the bearing: Axial load is any load that is parallel to the axis of rotation of the bearing. Radial load is any load that is perpendicular to the axis of rotation.

Axial Play – The axial displacement of the shaft due to a reversal of an axial force.

Axis – A principal direction along which movement of a tool, component, or workpiece occurs. The components that control each degree of freedom in a machine can be considered an axis. An X-Y-Z machine is a three axis machine where the X and Y axes control movement in the horizontal plane and the Z axis controls up and down motion. Each axis can consist of a controller, drive, motor, and transmission components necessary to couple to the load.

Axes – Plural of axis.

Backlash – The play caused by loose connections between mechanical components. Backlash becomes a problem when an axis changes direction. When a motor turns, it pushes all the gears together in one direction. When the motor reverses direction the gear teeth separate from one side and meet on the other side. The distance of separation is the backlash.

Ball screw – Ball screws are highly efficient, low-friction and low backlash lead screw devices that use ball bearings rolling in a channel cut into the screw. The low friction and backlash attributes are extremely valuable for precision applications where they are used to drive the axes of the machine.

Brushless Motors – Brushless Motors are a class of motors that operate using electronic commutation of phase currents, rather than electromechanical (brush-type) commutation. Brushless motors typically have a permanent magnet rotor and a wound stator.

Circular Interpolation – The generation of an apparently circular motion through the coordinated movements of two axes. The actual path is a series of straight line approximations generated by software algorithms.

Collision Detection – The use of sensors to detect the imminent impact of two or more parts in a motion control system. The signals from the detection sensors can be used to stop motion or to provide a ramped slow down for a "soft" mating of the approaching components.

Coordination – The integration of the movements of two or more axes of motion, so that the resultant motion is the path which none of the axes are capable of independently. Coordination may also involve the use of sensors and other internal or external commands in the integration effort which assist in effecting the movement or work desired.

Coupling (Couple, Coupler) – The transfer of energy from one circuit to another by means of the mutual capacitance between them. In feedback and control systems this is considered to be electrical noise and is a common problem.

Cut-to-Length – A sub-routine within a motion control process or a standalone process in which feed material is processed at a preset distance. The distance is set prior to the performance of the task, and/or a secondary task such as a cut-off of the feed material. Feedback systems are employed to ensure repeatability of the preset feed length.

Detent Torque – Detent torque is the holding torque when no current is flowing in the motor. The maximum torque which can be applied to the shaft of an un-energized step motor without causing continuous rotation. The minimal torque present in an un-energized motor. The detent torque of a step motor is typically about 1% of its static energized torque.

Dynamic Torque – the torque developed by a motor while stepping at low rates.

Efficiency – In physics: the efficient energy use, useful work per quantity of energy, or mechanical advantage over ideal mechanical advantage, often denoted by the Greek lowercase letter η (Eta). In thermodynamics: efficiency is energy conversion efficiency, a measure of second law thermodynamic loss. Thermal efficiency: useful work per the higher heating value of the fuel. In computing: Algorithmic efficiency is optimizing the speed and memory requirements of a computer program, while storage efficiency as the effectiveness of computer data storage.

Electronic Clutch – The process of generating a slave profile based on master position or time periods by enabling and disabling electronic cam or gearing functions.

Electronic Gearing – A method that stimulates mechanical gears by electrically synchronizing one closed-loop axis to a second axis (open- or closed-loop) through a variable ratio.

Electronic Line Shaft – A virtual axis that is used as the master axis on a machine to which other axes are synchronized by electronic gearing or camming profiles.

Encoder – An encoder is a feedback device. It consists of a disc, vane, or reflector, typically attached to a motor shaft to provide digital pulses, which are provided to a translator and /or counters. This provides positional information if fed into a counter. Speed information may be derived if the time between successive pulses is measured and decoded.

Encoder Resolution – The number of electrically identified positions occurring in 360 degrees of input shaft rotation.

Event – A change-of-state of an input parameter, such as the triggering of a limit switch or proximity sensor.

Fault – The error received when a drive or control has attempted an illegal process and becomes disabled.

Feedback – Feedback is the measurement of the parameter that is being controlled. For a positioning system to accurately compensate for an error, the actual position must be known relative to the commanded position. In this case, position feedback would be used to provide the actual position.

Feedback Signal – The actual value detected by a sensor as a process is taking place. The feedback signal is part of a closed-loop control system.

Feedforward – A method that "precompensates" a control loop for known errors due to motor, drive, or load characteristics to improve response. It depends only on the command, not the measured error.

Gantry – An overhead framework that is designed to linearly move in the X, Y, and/or Z axes. Tooling or other devices are generally designed into the framework to perform various functions as it moves from one location to another.

Gearbox – A system of gears that transmits mechanical power from a prime mover, such as an electric motor, to a typically rotary output device at a lower momentum, but a higher torque.

Holding Torque – Holding torque is the maximum torque that can be externally applied to the motor shaft without causing continuous rotation when one or more phases of the motor are energized.

Home Position – A reference position for all absolute positioning movements. Usually defined by a home limit switch and/or encoder marker. Normally set at power-up

Homing – Locating a unique reference position at power-up for axis calibration.

Indexer – In the context of stepper motor-based systems, the indexer is a device that provides step and direction control signals to a stepper motor driver. More sophisticated dedicated stepper motor controllers will also have I/O points and various other higher level functions and programmability similar to a PLC. In many cases, a PLC may be used as an Indexer.

Indexing – An axis or axes in the process of moving to a pre-programmed position, at a defined velocity and acceleration/deceleration rate.

Interpolation – A coordinated move of two or more axes in a linear and/or circular motion.

Jog – An axis running at a fixed velocity and acceleration/deceleration rate, in a selected direction, with no specific destination.

Lead – The linear distance a nut on a lead screw travels during one revolution of the lead screw, e.g. in/rev

Lead Screw – A device that converts rotary motion into linear motion.

Limits – Sensors within a motion system that alert the control electronics that a physical end of travel has approached and that the motion is not allowed in a specific direction.

Linear Actuator – A linear actuator is an actuator that creates motion in a straight line, as contrasted with the rotary motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion; many other mechanisms are used to provide a linear motion from a rotating motor.

Linear Servo Motor – A linear servo motor is a "flattened" servo motor where the rotor is on the inside, and the coils are on the outside of a moveable u-channel.

Linear Slide – Linear slides are precision products designed to turn motion or torque into straight-line movements. Linear slides are designed to move mounted mechanisms across a given axis. Complete slides normally consist of at least a base, a saddle, adjusting screw and a straight gib.

Load – Any external resistance (static or dynamic) to motion that is applied to the motor.

On-Axis Accuracy – Difference between ideal position and real position after the compensation of linear errors. Linear errors include: cosine errors, inaccuracy of screw or linear scale pitch, angular deviation at the measuring point (Abbe error) and thermal expansion effects. The relation between absolute accuracy and on-axis accuracy is as follows:

Absolute Accuracy = On-Axis Accuracy + Correction Factor x Travel

Override – To force an axis to move during a faulted condition; often required to force an axis to move off of an over-travel limit switch.

Phasing – Adjusting the position of one axis with respect to others during synchronization or electronic line shafting. This is usually done while the axes are moving, and done to correct for small registration problems.

Pick and Place – An application in which objects are transferred from one place to another, such as a pill-sorting machine, medical vial (test tube) testing, or air-sample tester.

Pitch – The distance from any point on one thread of the screw to a corresponding point on the next successive thread, e.g. rev/in.

Positioning – Specifying a move by giving a target position, a velocity, and an acceleration rate. The target position can be an absolute position or a relative position from the current position.

Position Control – A type of control system designed for moving objects or machines to a known position. For example: stepper motors are used for position control.

Position Loop – The position loop operates by continuously comparing the target position with the current position. The difference between these two is the position error or following error.

Rated Speed – the speed specified by the manufacturer at which the motor produces its maximum rated power

Rated Torque – The rated torque is the torque-producing capacity of a motor at a given speed. This is usually specified with a torque/speed curve.

Servo Mechanism – A servomechanism may or may not use a servo motor. For example, a household furnace is a servomechanism that is controlled by a thermostat. Once a set temperature is reached, feedback signals the system to shut off, making it a "servo" in nature. The term "servo" describes more of a function or task, than it does a specific product line. The defining feature of a servomechanism is the use of feedback, creating a closed-loop system.

Servo Motor – A servo motor is a motor which is part of a servomechanism. It is typically paired with some type of encoder to provide positioning and speed feedback. A servo motor is an automatic device that uses an error-correction routine to control its motion. The term servo can be applied to systems other than a servo motor; systems that use a feedback mechanism such as an encoder or other feedback device to control the motion parameters. Typically, when the term servo is used, it applies to a 'Servo Motor' but is also used as a general control term, meaning that a feedback loop is used to position an item. A servo motor can be a DC, AC, or brushless DC motor, combined with a position sensor – in most cases, a digital encoder. The defining feature of a servo motor is that it operates in a closed-loop system (uses feedback).

Shielded Cable – an electrical cable with a common conductive layer surrounding its conductors, which is meant to provide electromagnetic shielding, thereby preventing EMI issues

Stepper Motor – A stepper motor (also referred to as step or stepping motor) is an electromechanical device achieving mechanical movements through conversion of electrical pulses. Stepper motors are driven by digital pulses rather than by a continuous applied voltage. Unlike conventional electric motors which rotate continuously, stepper motors rotate, or step, in fixed angular increments. A stepper motor is most commonly used for position control. With a stepper motor/driver/controller system design, it is assumed the stepper motor will follow digital instructions. One important aspect of stepper motors is the lack of feedback to maintain control of position, which classifies stepper motors as open-loop systems. Stepper motors can rotate forward or in reverse, but they cannot move large loads.

Step – A step is the movement of the rotor of a stepper motor from one energized position to the next.

Step Angle – The step angle is the nominal angle through which the shaft of a stepper motor turns between adjacent step positions. Step angle depends upon the motor and driving sequence (mode of drive). Smaller step angles result in higher resolution.

Step Increment – Step increment is an indication of step or motion size. Usually this is specified in degrees for a rotary motor and inches or millimeters for a linear motor.

Step (Stepping, Stepper) Motor – A Stepper is synonymous with Step and Stepping motor: a digital actuator, which operates from discrete pulses (input signals) and produces motion in discrete increments, which may be rotary or linear. See stepper motor definition above.

Step Position – the angular position that the shaft of an unloaded step motor assumes when energized. The step position is not necessarily the same as the detent position.

Torque – A rotational force. Torque is measured in N*m, lb*in, lb*ft, etc. 1 N*m is the torque produced by 1N of force applied to a lever arm that is 1m long.

Torque Limiter – A torque limiter is a mechanical protection device which causes the load to separate from the drive when an overload happens

Yaw, Pitch – Rotation of carriage around the Z axis (Yaw) or Y axis (Pitch), when it moves. The testing of on-axis accuracy, repeatability, and reversal error are made systematically with test equipment in an air-conditioned room (20 °C±1 °C). A linear cycle with 21 data points on the travel and 4 cycles in each direction gives a total of 164 points.