Fig. 8
a Enon robot and b the graphical idea used to describe possible cases during navigation. If the robot collides with a human, we consider it as a ‘Fail’ case. A ‘Safe’ case is when the robot can avoid a human but there are high overlapping regions of personal space. The robot achieves ‘Smooth’ collision avoidance when it can avoid a collision with the human and also has a small overlapping region of personal space. Lastly, a ‘Success’ case refers to the situation when the robot successfully maintains an appropriate distance when it is approached by a human