S-0-0348 Acceleration feed forward gain

The parameter contains the acceleration pre-control. 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

Datatype

udec

Data length in bit

16

Decimal point

4

Min value

0.0000

Default

0.0000

Max value

3.2767

Unit

% / (rad/s²)

Changeable in EtherCAT state

PreOp, SafeOp, Op

Cyclic transfer

No

Device parameter

No

Related to interface revision

from Rev. 203

The acceleration pre-control generates a set current that is added to the control value of the velocity controller (pre-control). This parameter can be used to adapt the effect of acceleration pre-control to the application, by linearly scaling the acceleration calculated by dual differentiation of the set position. The acceleration pre-control can only be used in connection with cubic interpolation (P-0-0556), because a set acceleration can only be calculated from a third-order interpolation.

When a feature bit is set (e.g. P-0-0010; Feature Bit 16), the calculation is internal.

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 = torque-generating motor current

Calculation example:

S-0-0348 Acceleration feed forward gain 1:

S-0-0348 Acceleration feed forward gain 2:

Parameter calculation:

Jtot = kg m2

KT = Nm / Arms

P-0-0092 = Arms

100% = Full compensation

Example:

S-0-0348 Acceleration feed forward gain 3:
S-0-0348 Acceleration feed forward gain 4:

Nested structure

Note the nesting depth and the structure information at the start of the descriptions.

S-0-0348 Acceleration feed forward gain 5:

For further information please look into the involved IDN:

P-0-0505, P-0-0092, P-0-0556