Pt2 Element Of The Speed Controller; Band-Rejection Filter; Acceleration Feedforward - HEIDENHAIN TNC 426 PB/M Technical Manual

Table of Contents

element of the

speed controller

Acceleration

December 2001

If the controlled system is insufficiently damped (e.g. direct motor coupling or

roller bearings), it will be impossible to attain a sufficiently short settling time

when the step response of the speed controller is adjusted. The step

response will oscillate even with a low proportional factor:

In MP2530.x, enter a value for damping high-frequency interference

oscillations. If the value you choose is too high, the k

controller and the integral factor of the speed controller is reduced. Realistic

input values: 0.0003 to 0.0020

MP2530.0-8 PT

element of the speed controller (2nd-order delay) for

0 to 1.0000 [s]

With the band-rejection filter you can damp oscillations that you cannot

compensate with the differential factor, the PT

With the oscilloscope of the TNC, find the fundamental frequency of the

interference oscillations and enter them in MP2550.x.

Increase MP2540.x incrementally until the interfering oscillation is

minimized. If you set the damping too high, you will limit the dynamic

performance of the control loop. Realistic input values: 3 to 9 [dB]

MP2540.0-8 Band-rejection filter damping for axes 1 to 8

0.0 to 18.0 [dB]

MP2550.0-8 Band-rejection filter center frequency for axes 1 to 8

0.0 to 999.9 [Hz]

Acceleration feedforward functions only in velocity feedforward control in

parallel with the speed controller.

At every change in velocity, spikes of short duration appear in the following

error. With acceleration feedforward control you can minimize these spikes:

First adjust the friction compensation. Enter values in MP2610.x to

From the integral-action component of the nominal current value I (N INT)

calculate the input value for MP2600.x.

Adjust the acceleration feedforward control with MP2600.x.

The Control Loop

factor of the position

element, or the low-pass