bnp-b2365(eng)b.pdf - 第203页

4. Servo Adjustment 4 - 4 4-2 Gain adjustment 4-2-1 Current loop gain No. Abbrev . Parameter name Explana tion Setting range SV009 IQA Current loop q a xis lead compensation SV010 IDA Curre nt loop d axis lead compensati…

4. Servo Adjustment

4 - 3

4-1-2 Output data settings

No. Abbrev. Parameter name Explanation

SV061 DA1NO D/A output channel 1 data No. Input the No. of the data to be output to each D/A output channel.

SV062 DA2NO D/A output channel 2 data No.

No. Output data Original data unit

Output magnification

standard setting value

(SV063, SV064)

Output unit for standard

setting

Output

cycle

-1 D/A output not selected

For 2-axis drive unit (MDS-C1-V2). Set the parameters to another axis in the drive unit that is not D/A

output.

13 (2000r/min) 1000r/min/V 3.55ms

ch1: Speed feedback r/min

9 (3000r/min) 1500r/min/V 3.55ms

ch2: Current command Stall % 131 Stall 100%/V 3.55ms

1 Current command Stall % 131 Stall 100%/V 3.55ms

2 -

3 Current feedback Stall % 131 Stall 100%/V 3.55ms

4 -

5 -

6 Position droop NC display unit/2 328 (Display unit = 1µm) 10µm/0.5V 3.55ms

7 -

8 Feedrate (F∆T)

(NC disiplay unit/2)/

Communication cycle

55 (1µm, 3.5ms) 1000 (mm/min)/0.5V 3.55ms

9 -

10 Position command NC display unit/2 328 (Display unit = 1µm) 10µm/0.5V 3.55ms

11 -

12 Position feedback NC display unit/2 328 (Display unit = 1µm) 10µm/0.5V 3.55ms

13 -

Collision detection

estimated torque

Stall % 131 Stall 100%/V 3.55ms

Collision detection

disturbance torque

Stall % 131 Stall 100%/V 3.55ms

Current command

(high-speed)

Internal unit 8 (adjustments required) - 888µs

Current feedback

(high-speed)

Internal unit 8 (adjustments required) - 888µs

Estimated disturbance

torque

Internal unit 8 (adjustments required) - 888µs

125

Test output saw tooth

wave

0V to 5V 0 (256) Cycle: 227.5ms 888µs

126 Test output oblong wave 0V to 5V 0 (256) Cycle 1.7ms 888µs

127 Test output 2.5V (data 0) 2.5V 0 (256) - 888µs

4-1-3 Setting the output magnification

Normally, set the standard setting value for the output scale (SV063, SV064). When "0" is set, the

magnification will be the same as "256".

DATA ×

SV063

256

5 [V]

256

(

8 bit

)

+ 2.5 [V] (Offset) = Output voltage [V]

(Example) To output current FB with stall 100%/V unit (SV061=3, SV063=131)

100 ×

131

256

+ 2.5 = 3.499 [V]

No. Abbrev. Parameter name Explanation Setting range

SV063 DA1MPY D/A output channel 1

output scale

SV064 DA2MPY D/A output channel 2

output scale

Set the output magnification with a 1/256 unit.

When "0" is set, the magnification will be the same as "256".

-32768 to 32767

(1/256-fold)

4. Servo Adjustment

4 - 4

4-2 Gain adjustment

4-2-1 Current loop gain

No. Abbrev. Parameter name Explanation Setting range

SV009 IQA Current loop q axis lead

compensation

SV010 IDA Current loop d axis lead

compensation

1 to 20480

SV011 IQG Current loop q axis gain

SV012 IDG Current loop d axis gain

Set the gain of current loop.

As this setting is determined by the motor’s electrical

characteristics, the setting is fixed for each type of motor.

Set the standard values for all the parameters depending on

each motor type.

1 to 8192

4-2-2 Speed loop gain

(1) Setting the speed loop gain

The speed loop gain 1 (SV005: VGN1) is an important parameter for determining the

responsiveness of the servo control. During servo adjustment, the highest extent that this value

can be set to becomes important. The setting value has a large influence on the machine cutting

precision and cycle time.

[1] Refer to the following table and set the standard VGN1 according to the size of the entire load

inertia (motor and machine load inertia).

[2] If the standard speed gain setting value is exceeded, the current command fluctuation will

increase even if the speed feedback fluctuates by one pulse. This can cause the machine to

vibrate easily, so set a lower value to increase the machine stability.

Set the standard VGN1. Use the standard value if no problem (such as machine resonance)

occurs. If sufficient cutting precision cannot be obtained at the standard VGN1, VGN1 can be

raised above the standard value as long as a 70 percent margin in respect to the machine

resonance occurrence limit is maintained. The cutting accuracy can also be improved by adjusting

with the disturbance observer.

Machine resonance is occurring if the shaft makes abnormal sounds when operating or stopping,

and a fine vibration can be felt when the machine is touched while stopped. Machine resonance

occurs because the servo control responsiveness includes the machine resonance points. (Speed

control resonance points occur, for example, at parts close to the motor such as ball screws.)

Machine resonance can be suppressed by lowering VGN1 and the servo control responsiveness,

but the cutting precision and cycle time are sacrificed. Thus, set a vibration suppression filter and

suppress the machine resonance (Refer to section "4-3-2 Vibration suppression measures"), and

set a value as close as possible to the standard VGN1. If the machine resonance cannot be

sufficiently eliminated even by using a vibration suppression filter, then lower the VGN1.

Load inertia scale (%)

Isolated motor

100

200

500

400

300

100 200 400 600300 500

Load inertia scale (%)

Standard

VGN1

Isolated motor

100

200

500

400

300

100

200 400 600300 500

HC52~HC152

HC202~HC902

HC53~HC203

<HC>

HC353~HC703

HA40N

HA80N/100N/900N

HA43N~HA103N

<HAN>

HA053~HA33N

HA200N~HA700N

HA203N~HA703N

High-gain specifications High-gain specifications

4. Servo Adjustment

4 - 5

No. Abbrev. Parameter name Explanation Setting range

SV005 VGN1 Speed loop gain 1

Set the speed loop gain.

Set this according to the load inertia size.

The higher the setting value is, the more accurate the control will be,

however, vibration tends to occur.

If vibration occurs, adjust by lowering by 20 to 30%.

1 to 999

POINT

The final VGN1 setting value is 70 to 80% of the maximum value at which the

machine does not resonate.

Suppressing the resonance with the vibration suppression function and increasing

the VGN1 setting is effective for adjusting the servo later.

(2) Setting the speed loop lead compensation

The speed loop lead compensation (SV008: VIA) determines the characteristics of the speed loop

mainly at low frequency regions. 1364 is set as a standard, and 1900 is set as a standard during

SHG control. The standard value may drop in respect to loads with a large inertia.

When the VGN1 is set lower than the standard value because the load inertia is large or because

machine resonance occurred, the speed loop control band is lowered. If the standard value is set

in the leading compensation in this status, the leading compensation control itself will induce

vibration. In concrete terms, a vibration of 10 to 20Hz could be caused during acceleration/

deceleration or stopping, and the position droop waveform could be disturbed when accelerating to

a constant speed and when stopped. (Refer to lower left drawing)

This vibration cannot be suppressed by the vibration suppression functions. Lower the VIA in

increments of 100 from the standard setting value. Set a value where vibration does not occur and

the position droop waveform converges smoothly. Because lowering the VIA causes a drop in the

position control's trackability, the vibration suppression is improved even when a disturbance

observer is used without lowering the VIA. (Be careful of machine resonance occurrence at this

time.)

If VIA is lowered, the position droop waveform becomes smooth and overshooting does not occur.

However, because the trackability in respect to the position commands becomes worse, the

positioning time and accuracy are sacrificed. VIA must be kept high (set the standard value) to

guarantee precision, especially in high-speed contour cutting (generally F = 1000 or higher). In other

words, in a machine aiming for high speed and high accuracy, a large enough value must be set in

VGN1 so that VIA does not need to be lowered. When adjusting, the cutting precision will be better if

adjustment is carried out to a degree where overshooting does not occur and a high VIA is

maintained, without pursuing position droop smoothness.

Vibration waveform with lead compensation control Adjusted position droop waveform

Speed FB

Position

droop

Time

D/A output range

Time