5-15
5.5.2
Velocity Profile
In a trapezoidal motion, the acceleration of the moving part follows the acceleration type set by the
#4 Selecting
acceleration type
parameter until it reaches the feed velocity. Hereafter, the move is continued with the feed
velocity, then decelerates and stops according to the deceleration type set by the
#5 Selecting deceleration
type
parameter. The feed velocity varies depending on the operation.
The acceleration and deceleration types can be selected separately. There are two options for acceleration and
deceleration: a
constant acceleration type
and an
S-shaped type
(where the acceleration/deceleration follows
a second order spline). Generally, the S-shaped type can limit vibrations in the machine better, but the peak
torque or peak thrust at acceleration/deceleration become greater and a correspondingly larger motor torque or
motor thrust will be required.
The acceleration/deceleration time can also be selected separately. The values of the
#7 Acceleration time
during a trapezoidal move
and
#8 Deceleration time during a trapezoidal move
parameters are set to
values equivalent to the maximum velocity shown in the
#357 Maximum velocity
monitor. The actual
acceleration/deceleration time becomes the value obtained by multiplying the maximum velocity by the velocity
ratio during a trapezoidal move. By doing so, the same acceleration can be maintained without changing #7 and
#8 even when the feed velocity setting is changed.
[Constant
acceleration]
[Acceleration]
[Deceleration]
Feeding Velocity
Maximum velocity
#7 Acceleration time during a
trapezoidal move
Actual acceleration time
200ms/div
NORM:5kS/s
Waiting for trigger
Waiting for trigger
200ms/div
NORM:5kS/s
Actual deceleration time
Feeding Velocity
Maximum velocity
#8 Deceleration time during a
trapezoidal move
[Acceleration]
[
Deceleration
]
[S-shaped]
Waiting for trigger
Feeding Velocity
Maximum velocity
#7 Acceleration time during a
trapezoidal move
Actual acceleration time
200ms/div
NORM:5kS/s
Waiting for trigger
Feeding Velocity
Maximum velocity
#8 Deceleration time during a
trapezoidal move
Actual deceleration time
200ms/div
NORM:5kS/s
5
