English 
Chinese Radial runout:
The radial deviation of the center of rotation from its average position during one rotation of the platform.
Axial runout:
When the platform rotates one cycle, the size of the table surface changes in the direction of the rotation axis.
Travel Range:
In the case of ensuring accuracy, the running distance of the motion system.
Load:
For a linear stage, this is the maximum load that can be applied to the stage with the center of mass load at the center of the stage, perpendicular to the axis of motion and the surface of the stage. For rotating platforms, this refers to the maximum liability on the axis of rotation.
Maximum speed:
The maximum speed refers to the maximum speed at which the system can run continuously and stably under the rated load. For a short-stroke stage, the limitation of its travel is also a key influence on the maximum speed of the motion system.
Resolution:
The smallest amount that the motion system can measure. (Note that the resolution is not equal to the minimum motion increment, and being able to distinguish does not mean that the minimum step size motion can be performed at the resolution)
Minimum Motion Increment:
The smallest increment of motion is the smallest amount that the kinematic system can move under continuous, stable conditions. In general, the system resolution is much smaller than the smallest motion increment. Considering the influence of the transmission structure and the encoder on the system error, the minimum motion increment of the linear motor stage is closer to the resolution than that of the stepper motor stage.
Accuracy:
Accuracy and repeatability are confusing concepts. Generally, the two concepts can be easily distinguished by using the target shooting description shown in Figure 1.
One-way repeat positioning accuracy:
Figure 1 shows the difference between accuracy and repeatability. One-way repeat positioning accuracy refers to the repeatability index of moving from the same direction to a specified position multiple times.
Bidirectional Repeated Positioning Accuracy:
Figure 1 shows the difference between accuracy and repeatability. Bidirectional repeatability refers to the repeatability index of moving from two directions to the specified position multiple times.
Only when parameters such as straightness, parallelism, pitch, and Yaw meet high-level requirements, the accuracy and repeatability of the motion system can reach high-precision levels. That is to say, customers generally only need to consider whether the accuracy and repeated positioning accuracy meet the application requirements, and then they can choose a satisfactory displacement platform. When customers have higher requirements for platform motion, the following parameters need to be considered.
From Figure 2, the physical meaning of the basic parameters of the motion system can be intuitively understood.
The motion platform is based on the right-hand XYZ rectangular coordinate system, and its origin is located at the center of the platform surface. The X direction is the positive direction of the axial motion, the Z direction is the outward direction perpendicular to the table surface, and the Y direction points horizontally. During the movement, the movement of the platform rotating with the X axis is called Roll, the movement with Y as the axis is called pitch, and the movement with Z as the axis is called yaw.
Ideally, during the movement process, the center of the platform only moves in the X direction, and there are no components in the Y and Z directions. However, due to the influence of the guide rail, the transmission device, and the machining accuracy, the center of the platform will deviate from the Y axis, resulting in two Y and Z. direction of movement. The amount of movement in the Y direction is called Straightness. The amount of movement in the Z direction is called Flatness,
