Legend for figure Control Structure
Position Controller/Feed
Forward Control
see 7.5 Position controller settings
Position controller
see 7.5 Position controller settings
Speed controller
Digital filter
Current Controller
Filter/observer
see 7.3.6 Advanced torque control
Field weakening,
asynchronous
see 7.6 Asynchronous motor field weakening
Field weakening,
synchronous
see 7.7 Field weakening and LookUpTable (LUT),
synchronous motor
Scanning times of the individual control circuits:
Switching frequency
Sampling time
Current Controller
Speed controller
Position controller
2 kHz
250
µ
s
250
µ
s
250
µ
s
4 kHz (12 kHz)
125
µ
s
125
µ
s
125
µ
s
8 kHz
(Presetting)
62.5
µ
s
125
µ
s
125
µ
s
16 kHz
62.5
µ
s
125
µ
s
125
µ
s
Table 7.1: Scanning times of the individual control circuits
The control system is set up in a cascaded configuration. The position, speed and
current controllers are configured in sequence. The sequence of controller setup
must always be observed in controller optimization.
1. Current controller setup
2. Speed controller setup
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
109
7 Control
3. Setting for position controller / Pre-control
7.1.1 Setting
When using a standard Moog motor data set, the control parameters are preset for
the specific motor model (external mass inertia = motor inertia). If using third-party
motors, a manual setting must be made for the drive by way of the motor
identification or by calculation in order to define the appropriate control parameters
for the motor model.
7.1.1.1 Speed control loop
The setting of the speed controller with the associated filters is dependent on the
motor parameters (moment of inertia, torque/force constant, load inertia/mass,
friction, rigidity of the connection and encoder quality). Consequently, a manual or
automatic optimization is often required.
7.1.1.2 Position control loop
The position control loop is dependent on the dynamism of the underlying speed
controller, on the setpoint (reference) type and on the jerk, acceleration and
interpolation methods.