Pitch, Roll, And Yaw; Figure 6.2-7 - Hysteresis Plot; Figure 6.2-8 - Real Vs. Ideal Position - Newport ESP6000 User Manual

Section 6 — Motion Control Tutorial
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
+
Error
0
–
The error plot in reverse direction is identical with the first one but seems
to be shifted down by a constant error. This constant error is the Hysteresis
of the system.
To justify a little more why we call this error Hysteresis, let's graph the
information in a different format (Figure 6.2-8). Plotting the real versus the
ideal position will give us a familiar hysteresis shape.
position

6.2.9 Pitch, Roll, and Yaw

These are the most common angular error parameters for linear translation
stages. They are pure mechanical errors and represent the rotational error
of a stage carriage around the three axes. A perfect stage should not rotate
around any of the axes, thus the Pitch, Roll, and Yaw should be zero.
The commonly used representation of the three errors is shown in Figure
6.2-9. Pitch is rotation around the Y axis, Roll is rotation around the X axis
and Yaw around the Z axis.
Hysteresis
Figure 6.2-7 — Hysteresis Plot
Real
Trajectory (ideal position)
Figure 6.2-8 — Real vs. Ideal Position
Position
ideal plot
real plot
6 - 7