00195193-02 SG D4 FSE en (1) - 第161页

Axis dynamic Axis dynamic basics Servo amplifier TBS .. and SDS ... S tudent Guide SIPLACE D4 (FSE) Axis dynamic EN 09/2006 148 For assessment of the a xis dynamics by a service technician , the system gen erates an unco…

Axis dynamic

Servo amplifier TBS .. and SDS ... Axis dynamic basics

Student Guide SIPLACE D4 (FSE)

EN 09/2006 Axis dynamic

147

7.3 - 3: The 2nd overshoot sets the end signal

7.3 - 4: Positioning with asymptotic approach after the initial, excessive overshoot

The positioning shown above demonstrates an excessive overshoot. However, no other overshoot

occurs during this positioning process, which could create an end signal. The axis controller has a

’backup strategy’. When the permitted position deviation range is reached, a 10ms timer is started. 10

ms after entering the permissible position deviation range (1) (5 digits) the timer triggers the end signal

(2). The permitted range must not be left during this period.

Axis dynamic

Axis dynamic basics Servo amplifier TBS .. and SDS ...

Student Guide SIPLACE D4 (FSE)

Axis dynamic EN 09/2006

148

For assessment of the axis dynamics by a service technician, the system generates an uncommutated

current target signal from all motor current target signals. This informs you about the mechanical friction

in the axis system. This can be measured on the adapter board of the axis test box or at the Vreg output

of the SIPLACE axis tester (SAT).

The uncommutated target current signal is an envelope signal for the 2 visible motor current target

signals from the axis controller. The missing 3rd motor current signal is calculated at the Servoboard.

The known V nominal (V-target) speed signal and the force signal have been replaced by the motor

current target signals for DC or AC drives.

7.3 - 5: The uncommutaded nominal current signal (3) and the motor current signals (1) (2) of a AC Motor

The acceleration section can be recognized in the motor current target signal of the AC motor (4), due

to the high amplitudes needed to supply the axis mechanics with sufficient force. The frequency of this

signal section is low, due to the low speed. The amplitude becomes lower and lower because the

necessary motor force is reduced with increasing speed.

The frequency becomes higher because the speed of the motor is increased to a maximum for the

constant speed section (2).

In the deceleration section, the amplitude increases again, to reduce the speed of the axis mechanics.

The frequency become lower and lower (3). Finally, the axis is moved into the correct target position,

with overshoot control.

NOTE:

These motor current signals can be measured at the V nominal and the Force

output of the axis tester. The same signals are measured at the two topmost test

points of the servo amplifier board, as Inom. U’ and Inom. W signals.

Axis dynamic

Servo amplifier TBS .. and SDS ... Axis dynamic basics

Student Guide SIPLACE D4 (FSE)

EN 09/2006 Axis dynamic

149

So there is nothing to adjust all this axes have a dynamic behavior. Each axis has friction to be

overcome. The higher the friction is, the higher the amplitudes will be at acceleration and constant

speed. The higher motor force at acceleration and constant speed can be detected at the uncommutated

motor current target signal. Higher friction reduces the required motor force during the deceleration

section, so that the amplitude is smaller for the uncommutated motor current target signal.

7.3 - 6: Axis block diagram example X or Y-axis of HF/Siplace X machine

Although the various axis types differ in details, all control tasks are handled by the axis controller. Two

control signals for 2 or 3 phase axis drive are transmitted to the servo. For DC drives, we use the same

hardware principle, with only one control signal to the servo amplifier. The only feedback is provided by

the track signals from the incremental encoder to the axis controller - a tacho (Z/DP axis) is not

connected to the axis system.