BECKHOFF AX5000 S-IDN Parameters - Manual (Page 159)

S­IDNs
S­0­0348 Acceleration feed forward gain
The parameter contains the acceleration pre­control. This parameter is active in mode "Position control lag
less". It is used in selected applications to additionally reduce following errors during acceleration and
deceleration.
Attributes
Name Value
Format udec
Data length 16
Decimal point 4
Min value 0.0000
Max value 3.2767
Default value ­
Unit % / (rad/s²)
Changeable in EtherCAT state PreOp, SafeOp, Op
Cyclic transfer No
Device parameter No
Related to interface revision from 0203
The acceleration pre­control generates a set current that is added to the control value of the velocity
controller (pre­control). This parameter can be used to adapt the effect of acceleration pre­control to the
application, by linearly scaling the acceleration calculated by dual differentiation of the set position. The
acceleration pre­control can only be used in connection with cubic interpolation (P­0­0556), because a set
acceleration can only be calculated from a third­order interpolation.
Explanation:
m = torque
α = angular acceleration of the motor shaft
J_tot = total moment of inertia active at the motor
K_T = torque constant of the motor
i_q = torque­generating motor current
Calculation example:
Parameter calculation:
J
tot
= kg m 2
K
T
= Nm / A
rms
P­0­0092 = A
rms
100% = Full compensation
AX5000 ­ IDN­Descriptions 159 Version 3.1