Galil DMC-1700 Manual De Usuario
DMC-1700/1800
Chapter 6 Programming Motion • 127
PR 40000
Main move
BGX Start
motion
#Correct Correction
loop
AMX
Wait for motion completion
V1=10000-_DEX
Find linear encoder error
V2=-_TEX/4+V1
Compensate for motor error
JP#END,@ABS[V2]<2
Exit if error is small
PR V2*4
Correction move
BGX Start
correction
JP#CORRECT Repeat
#END
EN
#END
EN
Motion Smoothing
The DMC-1700/1800 controller allows the smoothing of the velocity profile to reduce the mechanical vibration of
the system.
the system.
Trapezoidal velocity profiles have acceleration rates which change abruptly from zero to maximum value. The
discontinuous acceleration results in jerk which causes vibration. The smoothing of the acceleration profile leads to
a continuous acceleration profile and reduces the mechanical shock and vibration.
discontinuous acceleration results in jerk which causes vibration. The smoothing of the acceleration profile leads to
a continuous acceleration profile and reduces the mechanical shock and vibration.
Using the IT and VT Commands:
When operating with servo motors, motion smoothing can be accomplished with the IT and VT
command. These commands filter the acceleration and deceleration functions to produce a smooth
velocity profile. The resulting velocity profile, has continuous acceleration and results in reduced
mechanical vibrations.
command. These commands filter the acceleration and deceleration functions to produce a smooth
velocity profile. The resulting velocity profile, has continuous acceleration and results in reduced
mechanical vibrations.
The smoothing function is specified by the following commands
:
IT x,y,z,w
Independent time constant
VT n
Vector time constant
The command, IT, is used for smoothing independent moves of the type JG, PR, PA and the command, VT, is used
to smooth vector moves of the type VM and LM.
to smooth vector moves of the type VM and LM.
The smoothing parameters, x,y,z,w and n are numbers between 0 and 1 and determine the degree of filtering. The
maximum value of 1 implies no filtering, resulting in trapezoidal velocity profiles. Smaller values of the smoothing
parameters imply heavier filtering and smoother moves.
maximum value of 1 implies no filtering, resulting in trapezoidal velocity profiles. Smaller values of the smoothing
parameters imply heavier filtering and smoother moves.
The following example illustrates the effect of smoothing. Fig. 6.7 shows the trapezoidal velocity profile and the
modified acceleration and velocity.
modified acceleration and velocity.
Note that the smoothing process results in longer motion time.
Example - Smoothing
PR 20000
Position
AC 100000
Acceleration
DC 100000
Deceleration
SP 5000
Speed
IT .5
Filter for smoothing
BG X
Begin