4-219
Detailed explanation of command words
4MELFA-BASIC IV
[Explanation]
(1) In circular interpolation motion, a circle is formed with three given points, and robot moves along the cir-
cumference.
(2) The posture is interpolation from the start point to the end point; the transit point posture has no effect.
(3) If the current position and start point do not match, the robot will automatically move with linear interpola-
tion (3-axis XYZ interpolation) to the start point.
(4) If paused during execution of a Mvr instruction and restarted after jog feed, the robot returns to the
interrupted position by JOINT interpolation and restarts the remaining circle interpolation.
The interpolation method (JOINT interpolation / XYZ interpolation) which returns to the interrupted
position can be changed by the "RETPATH" parameter. (Refer to
Page 369, "5.10 Automatic return set-
)
(5) If the start point and end point structure flags differ when equivalent rotation (constant 2 = 0) is specified,
an error will occur at the execution.
(6) Of the three designated points, if any points coincide with the other, or if three points are on a straight
line, linear interpolation will take place from the start point to the end point. An error will not occur.
(7) If 3-axis XYZ is designated for the constant 2, the constant 1 will be invalidated, and the robot will move
with the taught posture.
(8) Constant 2 designates the posture interpolation type. 3-axis XYZ is used when carrying out interpolation
on the (X, Y, Z, J4, J5, J6) coordinate system, and the robot is to move near a particular point.
(9) This instruction cannot be used in a constantly executed program.
Fig.4-12:Example of circular interpolation motion path 1
P2
P1
P3
M VR P1, P2, P3
M oves by XYZ
interpolation (3-axis
XYZ interpolation)
P_CURR
