User`s guide

Adept Cobra PLC600/PLC800 Robot User’s Guide, Rev C 175
Part Handling Considerations
For part handling, settling time while trying to achieve a position can be minimized by
centering the payload mass in the gripper. A mass that is offset from the tool rotation
point will result in excess inertia that will take longer to settle. In addition, minimizing
gripper mass and tooling weight will improve settling time. This could include using
aluminum versus steel, and removing material that is not needed on tooling.
Programming Considerations
The use of joint-interpolated versus straight-line motion has to be evaluated on a
case-by-case basis. In general, joint-interpolated motion is more efficient.
Nulling tolerances should be as loose as the application will permit. This has a direct
impact on cycle time.
Lastly, on jointed arms, changing the arm configuration (for example, lefty versus righty
for a SCARA robot) generally requires more time than maintaining the current
configuration during a motion.
10.2 The Coordinate System and Reference Frames
What is the World Coordinate System?
A robot location specifies the position and orientation of the robot tool tip in 3-dimensional space.
By default, the tool tip is the center of the mounting flange of the robot. Locations are, by default,
relative to the base of the robot. See Figure 10-2 for an example using an Adept SCARA robot. For
a default (world) location, the coordinate offsets are from the origin of the world coordinate system
(which is located at the base of the robot).