Closed-Loop Control; General Information - Siemens SINUMERIK 840D Function Manual

2.5

Closed-loop control

2.5.1

General information

Position control of an axis/spindle
The closed-loop control of an axis consists of the current and speed control loop of the drive
plus a higher-level position control loop in the NC.
The basic structure of an axis/spindle position control is illustrated below:
MD32410
MD32910
MD32895
MD32200
x
v
x
act
n
act
n
set
Figure 2-10 Block diagram of the setpoint processing and closed-loop control
For information on the jerk limitation, see Section "B2: Acceleration and jerk (Page 347)".
For a description of the feedforward control, backlash, friction compensation, and leadscrew
error compensation, see:
Further information
Function Manual Monitoring and Compensating; Compensations
Fine interpolation
Using the fine interpolator (FIPO), the contour precision can be further increased by reducing
the staircase effect in the speed setpoint. You can set three different types of fine interpolation:
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
G2: Velocities, setpoint / actual value systems, closed-loop control
$MA_AX_JERK_TIME
$MA_DYN_MATCH_TIME
$MA_DESVAL_DELAY_TIME
$MA_POSCTRL_GAIN
Position setpoint
Velocity setpoint
Position actual value
Speed actual value
Speed setpoint
2.5 Closed-loop control
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