Selection Example For Position Control - YASKAWA E-II Series User Manual

11 Appendix

11.1.2 Selection Example for Position Control

(9) Result
The provisionally selected servomotor and SERVOPACK are confirmed to be applicable.
The torque diagram is shown below.
(N m)
11
1.73
0
-7.5
0.1

11.1.2 Selection Example for Position Control

Mechanical Specifications
Linear motion
all screw
• Load speed: V = 15 m/min
• Linear motion section mass: M = 80 kg
• Ball screw length: L
• Ball screw diameter: D
• Ball screw lead: P
• Coupling mass: M
• Coupling outer diameter: D
(1) Speed Diagram
15
Speed
(m/min)
ta
(2) Rotation Speed
• Load axis rotation speed
N =
• Motor shaft rotation speed with direct coupling: Gear ratio 1/R = 1/1
Therefore,
N = N
M
(3) Load Torque
T =
L
11-4
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Torque
Speed
1.0 0.1
1.5
Servomotor
1
Coupling
= 0.8 m
B
= 0.016 m
B
= 0.005 m
B
= 0.3 kg
C
=0 .03 m
C
Reference
V
pulse
Load
speed
c t d t s t
Time (s)
tm
t
15
V
= = 3000 (min ) -1
P
0.005
B
×
R = 3000 1 = 3000 (min )
-1
9.8 × 0.2 × 80 × 0.005
9.8μ M P
B
=
2πR η 2π × 1 × 0.9
• Positioning times: n = 40 times/min
• Positioning distance: = 0.25 m
• Positioning time: tm = Less than 1.2 s
• Electrical stop accuracy: δ = ± 0.01 mm
• Friction coefficient: μ = 0.2
• Mechanical efficiency: η = 0.9 (90%)
60 60
1.5 s ( )
t = ----- - = ----- - =
n 40
Where ta = td, ts = 0.1 (s)
60
60
ta = tm − ts − = 1.2 − 0.1 −
V
× 0.9 s ( )
tc = 1.2 0.1 – – 0.1 2 =
= 0.139 (N m)
× 0.25
= 0.1 (s)
15