Newport MM4006, Руководство пользователя

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MM4006 M o t i o n Control Tutorial
amplifier or current (torque) driver. A special case is when the driver has
its own velocity feedback loop from a tachometer (Fig. 4.19).
Servo Controller
Trajectory
Generator
Motion Controller
x
• M o t o r
▶
x Ki
•
de
ilt
•
I I , •
•
▶
D r i v e r
•
Tachometer
Fig. 4.19 — Tachometer-driven PIDF Loop.
Encoder
The tachometer is a device that outputs a voltage proportional with the
velocity. Using its signal, the driver can maintain the velocity to be propor-
tional to the control signal. If such a driver is used with a velocity feed-for-
ward algorithm, b y properly tuning the Kvff parameter, the feed-forward
signal could perform an excellent job, leaving very little for the PID loop to
do.
The MM4006 uses this type of velocity control driver to get the highest per-
formance possible. In addition, since tachometers are expensive and many
times impractical or even impossible to use, the driver has a special cir-
cuitry tuned to each individual motor type that can "calculate" the velocity.
The results are similar to a tachometer feedback but at a fraction of a cost.
The drawback is that each motor type needs a specially tuned driver card
but, because it is designed to work in a predefined system using known
motion devices, its operation is totally transparent to the user. All driver
cards are pre-tuned and clearly labeled and no adjustments are required
(or allowed).
c v
N e w p o r t . 4 . 1 7 E D 1 1 0 1 8 1 E n 1 0 2 0 — 03/03