Baumuller b maXX BM3000 User Manual

Configuration
Parameter manual b maXX BM3000
Document no.: 5.12001.07 Baumüller Nürnberg GmbH
208
of 820
4.4
Example DS100M25 motor: Kt = 2.7 Nm/A, J
M
= 141 kg cm² = 0.0141 kg m²
n Motor without load (J
L
= 0):
Total torque J = J
M
+ J
L
= 0.0141 kg m²
Ks factor = (180°/) * Kt/J = (180°/) * 2.7 / 0.0141 = 10973 (degree/s²)/A
n Motor with load (J
L
= 0.9 kg m
2
) by a gear, gear factor GF = at a ratio of 3 to 1 (motor
rotates faster), encoder is on the motor side:
Total moment of inertia, converted to encoder side (here, motor side):
J = J
M
+ J
L
/GF² = 0.0141 + 0.9/9 = 0.1141 kg m²
Ks factor = (180°/) * Kt/J = (180°/) * (2.7 / 0.1141) = 1356 (degree/s²)/A
Ks measurement
Three methods of the Ks measurement are provided:
m One accelerating/braking measurement. "Ks was measured" Z52.8–.
m A FFT analysis specifically for the Ks measurement. Result: "Ks was measured"
Z52.8–.
m Ks measurement as a part of the automatic controller and filter setting by the FFT
analysis. See chapter
ZAutomatic controller and filter setting– from page 714.
If the result of the measuring is to be taken over, ProDrive copies the value of Z52.8– in
the parameter Ks factor Z18.40–.
The acceleration/braking methods are described in the following:
Ks measurement by accelerating/braking
The Ks factor (see chapter ZThe factor Ks– on page 446) can be evaluated by an accel-
eration and braking procedure or a speed change N between N1 and N2 in [degree/s].
The following motion model is used:
with:
a = abs( N/ t)
0 < |N1| < |n| < |N2|
[(Degree/s²)/A] is the unit for Ks and n is the speed in [degree/s]; a is the amplitude of the
acceleration or braking procedure in [degree/s
2
]. The factor b is the sliding friction in
[(A/degree)/s]. The factor c is the sliding friction in [A], and is signed depending on the
speed direction.
During the measurement the speed controller is applied with a great set value step
change so that the torque current goes in a specified limit (l
sq-lim
) (i.e. isq remains con-
stant during the acceleration or braking procedure).
By measuring the time t to change the specified speed N with limited current I
sq-lim
, Ks
can be evaluated as follows:
isq n t a
1
Ks
------ bn c++=

Baumuller b maXX BM3000 Specifications

General

Brand	Baumuller
Model	b maXX BM3000
Category	Measuring Instruments
Language	English