Siemens SINUMERIK 840D sl Function Manual page 316

Extended functions
Hide thumbs Also See for SINUMERIK 840D sl:
Table of Contents

Advertisement

K3: Compensations
5.5 Dynamic feedforward control (following error compensation)
MD32810 $MA_EQUIV_SPEEDCTRL_TIME (equivalent time constant speed control loop for
feedforward control)
Feedforward control factor for speed feedforward control (MD32610)
The additional velocity setpoint can be weighted using a factor:
MD32610 $MA_VELO_FFW_WEIGHT
Range of values: 0 ... 1
"0" means: no feedforward control. As standard, the factor has a value of 1 (≙ 100%).
The factor should remain set at 100%, as this value is the optimum setting for an optimally set
control loop for the axis/spindle as well as a precisely determined equivalent time constant of
the speed control loop.
Fine adjustment
The speed feedforward control for the particular axis/spindle can be optimized by making slight
changes (fine tuning) to the equivalent time constants of the speed control loop (MD32810).
To make this check, the axis/spindle should be traversed at a constant velocity and in the
service display "Axis/spindle", the "System deviation" should be checked.
A small acceleration and a high feedrate should be chosen so that the values can be easily
read on the service display. This produces very long acceleration phases from which it is easy
to read off the control deviation.
Example:
MD32300 $MA_MAX_AX_ACCEL = 0.1
MD32000 $MA_MAX_AX_VELO = 20000.0
; Part program for setting the equivalent time constant
G1 F20000
FFWON
LOOP:
X1000
X0
GOTOB LOOP
M30
References
For detailed information about setting the equivalent time constants of the speed control loop
(MD32810) refer to:
● Function Manual, Basic Functions; Velocities, Setpoint / Actual Value Systems, Closed-
Loop Control (G2), Section: Optimization of the control
316
; Maximum axis acceleration = 0.1 m/s
; Maximum axis velocity
= 20000.0 mm/min
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
2
Extended Functions

Advertisement

Table of Contents
loading

This manual is also suitable for:

Sinumerik 828d

Table of Contents