Galil Motion Control DMC-42 0 Series, Руководство пользователя

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Command Summary - Contour Mode
COMMAND DESCRIPTION
CM XYZW Specifies which axes for contouring mode. Any non-contouring axes may be operated in
other modes.
CM ABCDEFGH Contour axes for DMC-4280
CD x,y,z,w
Specifies position increment over time interval. Range is
±
32,000. CD 0,0,0.. .=0 ends the
contour buffer. This is much like the LE or VE commands.
CD a,b,c,d,e,f,g,h Position increment data for DMC-4280
DT n Specifies time interval 2 n sample periods (1 ms for TM1000) for position increment, where n
is an integer between 1 and 8. Zero ends contour mode. If n does not change, it does not
need to be specified with each CD.
_CM
Amount of space left in contour buffer (511 maximum)
General Velocity Profiles
The Contour Mode is ideal for generating any arbitrary velocity profiles. The velocity profile can be specified as a
mathematical function or as a collection of points.
The design includes two parts: Generating an array with data points and running the program.
Generating an Array - An Example
Consider the velocity and position profiles shown in Figure 6.20. The objective is to rotate a motor a distance of
6000 counts in 120 ms. The velocity profile is sinusoidal to reduce the jerk and the system vibration. If we describe
the position displacement in terms of A counts in B milliseconds, we can describe the motion in the following
manner:
 
 
 



1 2 cos( )
  
AT
B
A
B
2
2


sin( )
Note: ω is the angular velocity; X is the position; and T is the variable, time, in milliseconds.
In the given example, A=6000 and B=120, the position and velocity profiles are:
X = 50T - (6000/2π) sin (2πT/120)
Note that the velocity, ω, in count/ms, is
ω = 50 [1 - cos 2πT/120]
Figure 6.20: Velocity Profile with Sinusoidal Acceleration
The DMC-42x0 can compute trigonometric functions. However, the argument must be expressed in degrees. Using
our example, the equation for X is written as:
Chapter 6 Programming Motion ▫ 87 DMC-42x0 User Manual