BUT, what about the Config?
There are two basic categories most applicable to our task:
- SCARA - Selectively Compliant Articulated Robot Arm
- PUMA - Programmable Universal Machine for Assembly
- PROs
- compliant (not rigid) in X-Y plane BUT not Z direction.
- accurate and precise due to rigidity
- adept at pick-and-insert operations
- CONs
- less flexibility in potential operations
- smaller workspace
PUMA (similar to 2 Wrist + Prismatic config proposed earlier)
- PROs
- more flexibility in potential operations
- larger workspace
- CONs
- compliant in X, Y and Z directions.
- less accurate and precise due to less rigidity
- adept at operations that do NOT require high precision, ie welding and stacking, etc.
Great points, believe you have brought up all the major points for both robots. I would have considered that the PUMA compliant in XYZ directions as a Pro, but given our assignment we can forgo a direction and that the extra directional flexibility would be a con (in regards to motor sizing, power input, extensive programming, etc.).
ReplyDeleteWe would probably like the best precision performance that is cost-effective and reliable. Since there is not a lot of complexity defined as to where the liver is in the human body and how we should approach the body, the SCARA sounds like a great option right now. Your thoughts Belaye?
Yeah, basically it comes down to this:
ReplyDeleteThe SCARA is more rigid but limited in the directions it can reach the liver(ie only form above +/- a few degrees about X or Y axes)
The PUMA is less rigid but potentially can reach the liver from above or the sides.
For me, the tie breaker is the rigidity of SCARA, since I think we are more concerned with the precision of the needle placement and less with what direction we reach the liver from (if it makes sense we may want to think about accessibility of the liver, but not sure if this is part of the project task since we are to assume its a sphere anyway)
As you point out, cost-effective precision performance should probably be the deciding factor in selecting SCARA over PUMA.