Siemens SINUMERIK 840D Description Of Functions page 112

4 Firmware Drive Functions
4.3 Closed-loop velocity control
Reference model
5414
SPEEDCTRL_REF_MODEL_FREQ [n]
Natural frequency of reference model
Unit: Default:
Hz 150.0
5415
SPEEDCTRL_REF_MODEL_DAMPING [n]
Reference model damping
Unit: Default:
– 0.9
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SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
0...7 index of the parameter set
Minimum: Maximum:
0.0 1000.0
Minimum: Maximum:
0.4 1.0
The dynamic response of the velocity control loop to control commands without
an I component in the velocity controller is simulated in the reference model. In
the ideal case of exact simulation, there is no deviation after the setpoint/actual
value comparison on the integrator under no-load conditions. In practice, veloc-
ity overshoots in the response to control commands can be reduced in this way.
The reference model is parameterized by settings for natural frequency
(MD5414) and damping (MD 5415).
Controller optimization reference model:
Precondition: I-component=0 (MD 5409=0)
Objective: Overshooting in response to setpoint changes caused by the I
component can be reduced by means of the reference model.
Procedure:
1. Set I-action gain
to zero (make note of original values!).
2. Record frequency response of the closed (adjusted and optimized) velocity
control loop.
3. Adjust the frequency response of the reference model by matching the filter
natural frequency (MD 5414) and filter damping (MD 5415) to the frequency
response recorded in point 2..
In the ideal case of exact simulation, there is no deviation after the setpoint/
actual value comparison on the integrator.
4. Enter I-action gain as calculated in the preceding optimization step.
Relevant for:
HLA
Data type:
FLOAT
0...7 index of the parameter set
Relevant for:
HLA
Data type:
FLOAT
(MD 5406: SPEEDCTRL_GAIN_A)
(MD 5407: SPEEDCTRL_GAIN)
(MD 5408: SPEEDCTRL_GAIN_B)
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02.99
Cross ref.: –
Protection level:
3/3
Effective:
Immediately
Cross ref.: –
Protection level:
3/3
Effective:
Immediately