Parker EME
Setting up Compax3
192-120103 N13 C3I20T11 / C3I32T11 December 2010
195
Compax3 servo controller structure
Feed Foward Control
Vorsteuerung
PI-Current Controller
PI-Stromregler
Signal Acquistion
Signalerfassung
t
s
v
t
a
t
r
t
Setpoint generator
Setpoint position
Speed
Acceleration
Deceleration
Acceleration jerk
Deceleration jerk
aw, nw
iw, jw
x
n
i
P-Position Controller
P-Positionsregler
PID-Speed Controller
PID-Drehzahlregler
aw
nw
xw
jw
x:
Position actual value
n:
Actual (rotational) speed
i:
Actual current
value
x
w
:
Setpoint position value
n
w
:
Velocity setpoint value
j
w
:
Jerk setpoint value
a
w
:
Acceleration setpoint value
Limitation behavior
Each control variable is limited by the control (actuating) element. If the control
variable demanded by the controller is within the linear range (without limitation),
the control loop shows the behavior defined by the design. If the controller
demands however a higher control variable than permitted by the limitation, the
control variable is limited and the controller slows down.
You should therefore make sure that the control variable (output) of the controller
does not remain within the limitation or only for a very short time.
Cascade control
In this chapter you can read about:
Structure of a cascade control ....................................................................................... 195
Cascade structure of Compax3...................................................................................... 196
In drive technology, a cascading structure with several controllers (normally 3) is
often used. This improves the control behavior. For this, additional sensors must be
fixed within the control path. You will get the structure of a cascade control.
Structure of a cascade control
Z
Process / Prozess
X2
X1
W1
W2
Controller1
Regler 1
Controller 2
Regler 2
Process Part 1
Streckenteil 1
Process Part 2
Steckenteil 2
W1
Setpoint value (setpoint) for the superposed controller 2
W2
Setpoint value (setpoint) for the subordinate controller 1
X2:
Actual variable (actual value) for controller 2
X1:
Actual variable (actual value) for controller 1
Hint
