Hobbit: Providing Fall Detection and Prevention for the Elderly in the Real World

Table 1

Set of hand/arm postures/gestures considered for the gestural interface of Hobbit.

User command	Upper body gesture/posture	Robot command	Related scenarios/tasks
Yes	Thumb up-palm closed	Positive response to confirmation dialogues. YES gesture	All (1 m to 2 m distance to robot)
No	Close palm, waving with index finger up	Negative response to confirmation dialogues	All (1 m to 2 m distance to robot)
Come closer	Bend the elbow of one arm repeatedly towards the platform and the body	Reposition the platform closer to the sitting user	All (1 m to 2 m distance to robot)
Cancel task	Both open palms towards the robot	Terminate an on-going robot behavior/task	All
Pointing	Extend one arm and point in 3D space towards an object (lying on the floor)	Detect and grasp the object of interest towards the pointing 3D direction	Pick up an (unknown) object from the floor
Reward	Open palm facing towards the robot and circular movement (at least one complete circle is needed)	Rewards the robot for an accomplished action/task	Approach the user
Emergency	Cross hands pose (normal-range interaction)	Emergency detection, initiated by the user	Emergency detection