Trinamic QSH5718-51-28-101 - 57 x 57mm 2-Phase Stepper Motor, 1.8 Degree, 1.01Nm, 0 - 75Vdc, 2.8A 50-0035 Fiche De Données
Codes de produits
50-0035
QSH5718 Manual (V2.3/2011-APR-12)
14
Copyright © 2011, TRINAMIC Motion Control GmbH & Co. KG
6.5 Choosing the Commutation Scheme
While the motor performance curves are depicted for fullstepping and halfstepping, most modern drivers
provide a microstepping scheme. Microstepping uses a discrete sine and a cosine wave to drive both coils
of the motor, and gives a very smooth motor behavior as well as an increased position resolution. The
amplitude of the waves is 1.41 times the nominal motor current, while the RMS values equal the nominal
motor current. The stepper motor does not make loud steps any more – it turns smoothly! Therefore, 16
microsteps or more are recommended for a smooth operation and the avoidance of resonances. To operate
the motor at fullstepping, some considerations should be taken into account.
Driver Scheme
provide a microstepping scheme. Microstepping uses a discrete sine and a cosine wave to drive both coils
of the motor, and gives a very smooth motor behavior as well as an increased position resolution. The
amplitude of the waves is 1.41 times the nominal motor current, while the RMS values equal the nominal
motor current. The stepper motor does not make loud steps any more – it turns smoothly! Therefore, 16
microsteps or more are recommended for a smooth operation and the avoidance of resonances. To operate
the motor at fullstepping, some considerations should be taken into account.
Driver Scheme
Resolution
Velocity range
Torque
Comments
Fullstepping
200 steps per
rotation
rotation
Low to very high.
Skip resonance areas
in low to medium
velocity range.
Skip resonance areas
in low to medium
velocity range.
Full torque if dampener
used, otherwise reduced
torque in resonance area
used, otherwise reduced
torque in resonance area
Audible noise
especially at low
velocities
especially at low
velocities
Halfstepping
200 steps per
rotation * 2
rotation * 2
Low to very high.
Skip resonance areas
in low to medium
velocity range.
Skip resonance areas
in low to medium
velocity range.
Full torque if dampener
used, otherwise reduced
torque in resonance area
used, otherwise reduced
torque in resonance area
Audible noise
especially at low
velocities
especially at low
velocities
Microstepping
200 * (number
of microsteps)
per rotation
of microsteps)
per rotation
Low to high.
Reduced torque at very
high velocity
high velocity
Low noise,
smooth motor
behavior
smooth motor
behavior
Mixed: Micro-
stepping and
fullstepping for
high velocities
stepping and
fullstepping for
high velocities
200 * (number
of microsteps)
per rotation
of microsteps)
per rotation
Low to very high.
Full torque
At high velocities,
there is no
audible difference
for fullstepping
there is no
audible difference
for fullstepping
Table 6.3: Comparing microstepping and fullstepping
Microstepping gives the best performance for most applications and can be considered as state-of-the art.
However, fullstepping allows some ten percent higher motor velocities, when compared to microstepping. A
combination of microstepping at low and medium velocities and fullstepping at high velocities gives best
performance at all velocities and is most universal. Most Trinamic driver modules support all three modes.
6.5.1 Fullstepping
When operating the motor in fullstep, resonances may occur. The resonance frequencies depend on the
motor load. When the motor gets into a resonance area, it even might not turn anymore! Thus you should
avoid resonance frequencies.
motor load. When the motor gets into a resonance area, it even might not turn anymore! Thus you should
avoid resonance frequencies.
6.5.1.1 Avoiding motor resonance in fullstep operation
Do not operate the motor at resonance velocities for extended periods of time. Use a reasonably high
acceleration in order to accelerate to a resonance-free velocity. This avoids the build-up of resonances.
When resonances occur at very high velocities, try reducing the current setting.
A resonance dampener might be required, if the resonance frequencies cannot be skipped.
acceleration in order to accelerate to a resonance-free velocity. This avoids the build-up of resonances.
When resonances occur at very high velocities, try reducing the current setting.
A resonance dampener might be required, if the resonance frequencies cannot be skipped.