Mitsubishi Electric MELDAS C6 Programming Manual page 266

13. Program Support Functions
Pre-interpolation acceleration/deceleration
Acceleration/deceleration control is carried out for the movement commands to suppress the
impact when the machine starts or stops moving. However, with conventional post-interpolation
acceleration/deceleration, the corners at the block seams are rounded, and path errors occur
regarding the commanded shape.
In the high-accuracy control function mode, acceleration/deceleration is carried out before
interpolation to solve the above problems. This pre-interpolation acceleration/deceleration enables
machining on a machining path that more closely follows the command.
The acceleration/deceleration time can be reduced because constant inclination acceleration/
deceleration is carried out.
(1) Basic patterns of acceleration/deceleration control in linear interpolation commands
Acceleration/deceleration pattern
Normal mode
High-accuracy
control mode
G1btL/2
G1btL
G1tL
G1t1
Time
G1bF
G1bF/2
13.12 High-accuracy control
(a) Because of the constant time constant
acceleration/deceleration, the rising
clamp
edge/falling edge becomes more gentle as
the command speed becomes slower.
(b) The acceleration/deceleration time constant
can be independently set for each axis.
Linear type, exponential function type, or both
can be selected.
Note that if the time constant of each axis is
not set to the same value, an error will occur
in the path course.
G1tL
Time
#2002 clamp : G01 clamp speed
#2007 G1tL : Linear type acceleration/
clamp
#2008 G1t1 : Exponential function type
G1t1
(a) Because of the constant inclination type linear
acceleration/deceleration, the acceleration/
clamp
deceleration time is reduced as the command
speed becomes slower.
(b) The acceleration/deceleration time constant
becomes one value (common for each axis)
in the system.
#2002 clamp : G01 clamp speed
#1206 G1bF : Target speed
#1207 G1btL : Acceleration/deceleration time to
G1btL/2
G1bF and G1btL are values for specifying the
inclination of the acceleration/deceleration time;
G1btL
the actual cutting feed maximum speed is
clamped by the "#2002 clamp" value.
Time
258
deceleration time constant
acceleration/deceleration time
constant
target speed