Description of IDN P-0-0514

Description of IDN P-0-0514 1:

Mode

Default value: 1 Basic Observer

Here you can choose between the following settings:

0: Off = Velocity Observer not active
1: = Basic Velocity Observer active in basic mode (3rd order)
2: = Advanced Velocity Observer active in advanced mode (5th order) (from firmware 2.10)

Bandwidth

Default value: 500 Hz

Here you can set the bandwidth of the Velocity Observer. The filter effect can be intensified by reducing the bandwidth. Increasing the bandwidth reduces the filter effect. At low bandwidth the speed signal is very smooth, although in this case any interference takes longer to compensate.

A higher bandwidth enables faster correction of faults. The associated higher bandwidth of the velocity controller causes a larger current ripple.

The basic rule:

The higher the resolution and quality of the motor feedback system used, the higher the bandwidth can be set.

Correction factor lq to ACC

Default value: 1

If the moment of inertia for the motor and the load is set correctly in P-0-0071 or P-0-0127 (only for linear motors), the Observer can correctly calculate the axis acceleration from the measured current value:

Description of IDN P-0-0514 2:

The Observer uses the table M = M(i) stored in P-0-0074.

	Torque/current characteristic curve P-0-0074 Further information about the torque/current characteristic curve P-0-0074 can be found in chapter: „Torque (force) controller structure“ of this function manual.

The equation indicates that the calculated acceleration value is too large if the value for J_load is too small and vice versa. Depending on the load and coupling type between motor and load, part of the load may become decoupled at frequencies above the Observer bandwidth and may then no longer be active. The "Correction factor" can be increased, in order to compensate this. The value for the full moment of inertia of the load is also required for the acceleration pre-control and should therefore be entered as precisely as possible. If the acceleration pre-control was enabled, the correct value for the moment of inertia can be determined. It is the value at which the pre-control works perfectly with the 100% setting. The optimum value for the "Correction factor Iq / Acc" can be determined using a Bode diagram for the velocity controller.

Damping

Default value: 0.7

The value can only be changed in basic mode. The default value of 0.7 should remain unchanged, if possible.