Page 59 - Human Inspired Dexterity in Robotic Manipulation

Intuitive Control in Robotic Manipulation 55

hand stroked by the brush, his/her real hand is simultaneously brushed out of
sight. The position and timing of the brushing are synchronized as much as
possible. After seconds or minutes, the subject may perceive touches on the
dummy hand, or even feel the dummy hand is his/her own hand. Body
transfer illusion [11] is a further extended version of the RHI, extending
the illusion from a hand to the whole body.
Although the detailed mechanisms of RHI and body transfer illusion
remain to be completely elucidated, such perception of feeling in a part
or the entire body is intriguing in terms of the current interests of robotic
manipulation described in the previous section.

4.3 ROBOTICALLY ENHANCED ILLUSION

Usability and operability of a robotic manipulation system such as with MSS
may be improved if the robotic device is perceived as part of the user’s own
body. This is yet to be investigated; however, the hypothesis of the present
study is inspired by previous studies in multisensory integration and illusion.
Tele-manipulation in MSS involves the user’s self-motion. For the present
study, a novel simple robotic system was built that allows exploration of
multisensory illusions occurring in a MSS.
Fig. 4.2 shows the three main components of the MSS [12]: a master, a
slave, and a controller. The master is worn on the subject’s hand and was
implemented as a wearable device, attached using Velcro straps. This device
measures the joint angle at the metacarpophalangeal (MCP) joint of the
index finger using an optical encoder. It is designed to be fairly small and
lightweight (110 mm in height, 90 mm in width, 50 mm in depth, and
approximately 80 g in mass).

Motor

Encoder

Slave

Master
Fig. 4.2 A simple robotic system.