APPENDIXD. NOMOGRAPHS
B–63834EN/02
740
Fig. D.3(c) Initial value
Y
0
X
0
V
0
The initial value when cornering begins, that is, the X and Y coordinates
at the end of command distribution by the controller, is determined by the
feedrate and the positioning system time constant of the servo motor.
X
0
+ V
X1
(T
1
) T
2
)
Y
0
+ V
Y1
(T
1
) T
2
)
T
1
:Exponential acceleration / deceleration time constant. (T=0)
T
2
:Time constant of positioning system (Inverse of position loop gain)
The equations below represent the feedrate for the corner section in
X–axis direction and Y–axis direction.
V
X
(t) + (V
X2
–V
X1
)[1–
V
X1
T
1
–T
2
{T
1
exp(–
t
T
1
)–T
2
exp(–
t
T
2
)} ) V
X1
]
+ V
X2
[1–
V
X1
T
1
–T
2
{T
1
exp(–
t
T
1
)–T
2
exp(–
t
T
2
)}]
V
Y
(t) +
V
Y1
–V
Y2
T
1
–T
2
{T
1
exp(–
t
T
1
)–T
2
exp(–
t
T
2
)} ) V
Y2
Therefore, the coordinates of the tool path at time t are calculated from the
following equations:
X(t) +
ŕ
t
0
V
X
(t)dt–X
0
+
V
X2
–V
X1
T
1
–T
2
{T
1
2
exp(–
t
T
1
)–T
2
2
exp(–
t
T
2
)}–V
X2
(T
1
) T
2
–t)
Y(t) +
ŕ
t
0
V
Y
(t)dt–Y
0
+
V
Y2
–V
Y1
T
1
–T
2
{T
1
2
exp(–
t
T
1
)–T
2
2
exp(–
t
T
2
)}–V
Y2
(T
1
) T
2
–t)
D Initial value calculation
D Analysis of corner tool
path