Extraneous Robot motion path

[LuisC18]

Extraneous motion when preforming pick and place action has been an issue for the tictactoe game. The grasp message has fields for pre_grasp_approach (direction and distance), post_grasp_retreat and defines a pre_grasp pose for the location/orientation. The moveit documentation defines collsion objects for the move_group.pick function as well as the pick/place grasp messages to execute. Currently the O's for the tictactoe game are not imported as objects into the environment.

There is a moveit_tutorial for pick and place in cpp. There is also a grasp tutorial page that goes more in depth about the grasp pipeline.

This solution may be more complex than is needed for tictactoe; however, it seems like it could fix the extraneous movements issue at the key moments for picking and placing objects.

[LuisC18]

Extraneous motion is still an issue for game movement (Example). Final positions are correct but motion to pickup/placement is unreliable. Further investigation of Pilz motion planner could result in solution.