Mitsubishi Electric MELSEC-Q Series - Page 193

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6 POSITIONING CONTROL
(c) Reference-axis speed specification
The Motion CPU calculates the positioning speed of other axes (V
1 to V3)
based on the positioning speed (reference-axis speed : V) of the setting
reference-axis using each axis travel value (D
1 to D4).
Set the reference-axis No., reference-axis speed and each axis travel value
using the servo program.
4 axes linear interpolation control is shown below.
Axis 1 travel value : D
1 = 10000 [pulse]
Axis 2 travel value : D
2 = 15000 [pulse]
Axis 3 travel value : D
3 = 5000 [pulse]
Axis 4 travel value : D
4 = 20000 [pulse]
Reference axis speed : V = 7000 [pulse/s]
Reference axis : Axis 4
In this example, since the reference-axis is
axis 4, it is controlled with the positioning
speed specified with axis 4.
The Motion CPU calculates the positioning
speed of other axes using the following
calculation formulas:
[Program example]
<K 52>
ABS-4
Axis
Axis
Axis
Axis
Reference-axis speed
Reference-axis
1,
2,
3,
4,
10000
15000
5000
20000
7000
4
[pulse]
[pulse]
[pulse]
[pulse]
[pulse/s]
V = D / D V1 41Axis 1 positioning speed :
V = D / D V
2
Axis 2 positioning speed :
42
V = D / D V
3
Axis 3 positioning speed :
43
POINTS
(1) Reference-axis speed and positioning speed of other axes
• Be careful that the positioning speed of an axis for a larger travel value than
the reference-axis may exceed the setting reference-axis speed.
(2) Indirect specification of the reference-axis
• The reference-axis can be set indirectly using the word devices.
(Refer to Section 5.4.2.)
(3) Relationship between speed limit value, acceleration time, deceleration time
and rapid stop deceleration time.
• The real acceleration time, deceleration time and rapid stop deceleration
time are set by the reference-axis speed setting.
Speed
Speed limit value
Positioning speed (reference-axis speed)
Rapid stop cause occurrence
Time
1)
2) 4)
6)
5)
3)
1) Real acceleration time
2) Setting acceleration time
3) Real deceleration time
4) Setting deceleration time
5) Real rapid stop deceleration time
6) Setting rapid stop deceleration tim
e
Example