Determine default controller for the gripper (ros ticket #2885)

[ahendrix]

[berger] Options:

• Trajectory controller (problem is no force controllability)
• Effort controller (problem)
• Something based on Matt's controller - awesome controller, including input from fingertip sensors.
• Controller which wraps trajectory controller and effort controller, and mode-switches between them
• Controller which is a trajectory controller with a configurable maximum force

Conclusions (partial)

• Build awesome gripping controller, including sensor data, but not for basic shipping (partially because robots will ship with dummy finger-tips)
• Use some variation / wrapper of trajectory controller that allows control of force.
• Exact controller TBD.

[ahendrix]

[sglaser] Discussion with Matei and Kaijen:

• Definitely need some form of position control.
• Must be able to limit the maximum effort applied by the gripper.
• Velocity limiting would be a nice feature too.

Command possibilities:

• Topic for a position and a max force
• Two topics, one for position and one for max force
• Topic for a trajectory and a max force
• Two topics, one for a trajectory and one for max force

Decided:

• One topic for trajectories
• One topic to limit the max effort
• Node that sits on top and provides an Open/Close action

[ahendrix]

[sglaser] Finalized and ready for user testing.