4-223
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 center 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 Mvr3 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) 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.
(7) 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.
(8) The central angle from the start point to the end point always satisfies 0 < central angle < 180 degrees.
(9) Designate the positions so that the difference from the center point to the end point and the center point
to the distance is within 0.01mm.
(10) If the three points are on the same line, or if the start point and center point, or end point and center
point are the same, an error will occur.
(11) If the start point and end point are the same or if three points are the same, an error will not occur, and
the next command will be executed. Note that if the posture changes at this time, only the posture will
be interpolated.
(12) This instruction cannot be used in a constantly executed program.
Fig.4-14:Example of circular interpolation motion path 3
P2
P3
P1
P_CURR
MVR3 P1, P2, P3
Moves by XYZ
interpolation (3-axis
XYZ interpolation)
Ce
ntr
al
an
gle