bnp-b2365(eng)b.pdf - 第236页
4. Servo Adjustment 4 - 37 4-5 Settings for emergency stop Emergency stop in this section refe rs to the following states. [1] Emergency stop was input (including other axis ala rms) [2] NC power down was detected [3] A …
4. Servo Adjustment
4 - 36
<Adjustment method>
[1] Set the servo specifications (SV017: SPEC)/bit1 to 1, and turn the NC power ON again.
[2] Measure the position droop overshooting while increasing the dual feedback control time
constant (SV051: DFBT) in increments of 5ms. Adjust to the time constant where overshooting
does not occur.
[3] For the final setting value, set a value 1.5 to 2-fold the value adjusted in 3.
No. Abbrev. Parameter name Explanation Setting range
SV017 SPEC* Servo specification
selection F E D C B A 9 8 7 6 5 4 3 2 1 0
spm mpt mp abs vdir fdir vfb seqh dfbx fdir2
bit Meaning when "0" is set Meaning when "1" is set
1 dfbx Dual feedback control stop Dual feedback control start
SV051 DFBT
Dual feedback
control time constant
Set the control time constant in dual feed back.
When "0" is set, the actual value that is set is 1ms.
The higher the time constant is, the closer it gets to the semi-closed
control, so the limit of the position loop gain is raised.
0 to 9999
(ms)
SV052 DFBN
Dual feedback
control non-sensitive
band
Set the non-sensitive band in the dual feedback control.
Set to "0" as a standard.
0 to 9999
(
µm)
4. Servo Adjustment
4 - 37
4-5 Settings for emergency stop
Emergency stop in this section refers to the following states.
[1] Emergency stop was input (including other axis alarms)
[2] NC power down was detected
[3] A servo alarm was detected
4-5-1 Deceleration control
With the MDS-C1-V1/V2 servo drive unit, if the deceleration stop function is validated, the motor will
decelerate following the set time constant while maintaining the READY ON state. READY will turn
OFF and the dynamic brakes will function after stopping.
If an alarm, for which dynamic brakes are designated as the stopping method, occurs, the motor will
stop with the dynamic brakes.
<Features>
When the load inertia is large, deceleration stop can be executed at a shorter time than the
dynamic brakes.
(The stop time for the normal acceleration/deceleration time constants will be achieved.)
(1) Setting the deceleration control time constant
Set the time for stopping from the rapid traverse rate (rapid: axis specification parameter) in the
deceleration time constant for emergency stop (SV056: EMGt). The operation stops with the
position loop step when 0 is set.
If linear acceleration/deceleration is selected for rapid traverse, the same value as the
acceleration/deceleration time constant (G0tL) will be the standard value. If another
acceleration/deceleration pattern is selected, set rapid traverse to linear acceleration/deceleration
and adjust to a suitable acceleration/deceleration time constant. Use that value as the standard
value.
<Operation>
When an emergency stop occurs, the motor will decelerate at the same inclination from each
speed.
Deceleration control sequence
Forced READY OFF range
RAPID
SV056
Constant inclination
decele
r
ation
Motor speed
Time
Motor brake control output (CN20)
OFF
ON
Servo READY (READY)
ON
OFF
In-position (INP)
ON
OFF
READY OFF after in-position
SV055
Emergency stop (EMG)
ON
OFF
4. Servo Adjustment
4 - 38
No. Abbrev. Parameter name Explanation Setting range
SV055 EMGx
Max. gate off delay
time after
emergency stop
Set a length of time from the point when the emergency stop is input to
the point when READY OFF is compulsorily executed.
Normally, set the same value as the absolute value of SV056.
In preventing the vertical axis from dropping, the gate off is delayed for the
length of time set in SV048 if SV055’s value is smaller than that of SV048.
0 to 20000
(ms)
SV056 EMGt
Deceleration time
constant at
emergency stop
In the vertical axis drop prevention time control, set the time constant
used for the deceleration control at emergency stop. Set a length of time
that takes from rapid traverse rate (rapid) to stopping.
Normally, set the same value as the rapid traverse
acceleration/deceleration time constant.
When executing the synchronous operation, put the minus sign to the
settings of both of the master axis and slave axis.
-20000 to
20000 (ms)
(2) Deceleration control stop distanc e
The stopping distance LEMG when the motor is stopped with deceleration control during an
emergency stop can be approximated with the following expression. Note that the value will be
higher than this if the current is limited during deceleration.
L
EMG =
F
PGN1 × 60
+
1
2
×
F
60
×
F × EMGt
ra
p
id × 1000
(mm)
F : Feedrate during emergency stop (mm/min)
rapid : Rapid traverse rate (mm/min)
PGN1 : Position loop gain 1 (SV003) (rad/s)
EMGt : Deceleration time constant for emergency stop (SV056) (ms)
POINT
1. Deceleration control will not take place when a servo alarm, for which the
stopping method is dynamic, occurs. The motor will stop with dynamic
braking regardless of the parameter setting.
2. If the power fails and the deceleration time constant is set to a relatively long
time, the braking method may change from deceleration control to dynamic
braking due to a drop in the bus voltage in the drive unit.
CAUTION
If the deceleration control time constant (EMGt) is set to a value longer than the
acceleration/deceleration time constant, the overtravel point (stroke end point)
may be exceeded.
Take care as the axis could collide with the tool end.