Newport MM4006, Руководство пользователя

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MM4006 M o t i o n Control Tutorial
4.4 Motion Profiles
When talking about motion commands we refer to certain strings sent to a
motion controller that will initiate a certain action, usually a motion. There
are a number of common motion commands which are identified by name.
The following paragraphs describe a few of them.
4.4.1 M o v e
A move is a point-to-point motion. On execution of a move motion com-
mand, the motion device moves from the current position to a desired des-
tination. The destination can be specified either as an absolute position or
as a relative distance from the current position.
When executing a move command, the motion device will accelerate until
the velocity reaches a predefined value. Then, at the proper time, it will
start decelerating so that when the motor stops, the device is at the cor-
rect position. The velocity plot of this type of motion will have a trape-
zoidal shape (Fig. 4.20). For this reason, this type of motion is called a
trapezoidal motion.
Desired Velocity
Fig. 4.20 — Trapezoidal Motion Profile.
Time
The position and acceleration profiles relative to the velocity are shown in
Fig. 4.21.
Desired Velocity
Position
Time
Acceleration
Fig. 4.21 — Position and Acceleration Profiles.
Besides the destination, the acceleration and the velocity of the motion
(the constant portion of it) can be set by the user before every move com-
mand. Advanced controllers like the MM4006 allow the user to change
them even during the motion. However, the MM4006 always verifies that a
parameter change can be safely performed. If not, the command is ignored
and the motion continues as initially defined.
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4.18 N e v V p O r t .