Adept s650HS Quattro - Manual (Page 101)

Chapter 5: System Operation
NOTE: When MULTIPLE is asserted, the tool flange will always rotate the smallest
angle when the robot moves from one location to the next.
roll = -90 roll = +90
(A)
(B)
-180 +180
(B) Roll = 2 degrees
(A) Roll = -90 degrees
0
Figure 5-8. Motion with MULTIPLE Asserted
Side Effects
There are some interesting side effects when using the SINGLE and MULTIPLE instructions.
One of them is shown in the following figure, which shows the robot motions for the following
code:
MOVE A
MULTIPLE
MOVE B
BREAK
SINGLE
MOVE C
In this scenario, MUTLIPLE is asserted and the robot is commanded to move into the positive
half of the overlap zone (moving from location A [roll=-90] to location B [roll=2]). Next,
SINGLE is asserted and the robot is asked to move to location C (roll = 4). Even though the
zero-roll position has already been crossed, the robot will move in a counter-clockwise
direction to location C, instead of taking the shortest path. That happens because SINGLE
forces the tool-flange rotation angle to remain within ±180° - that is, the rotation is not
permitted to use the full 185-degree range of motion.
The lesson here is to be aware of the mode that the robot was in when it was commanded to
move into the overlap zone. In other words this weird rotation could have been avoided if the
robot moved into the overlap zone with SINGLE asserted. (But then, of course, a large rotation
would have been done during the motion to location B.)
Adept Quattro User's Guide, Rev F
Page 101 of 196