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Complete visuo-haptic-hand chapter

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Erwan Normand
2024-09-26 20:49:03 +02:00
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3-manipulation/visuo-haptic-hand/2-method.tex
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@@ -7,7 +7,7 @@ We evaluated both the delocalized positioning and the contact vibration techniqu
\subsection{Vibrotactile Positionings}
\label{positioning}
We considered five different positionings for providing the vibrotactile rendering as feedback of the contacts between the virtual hand and the \VO, as shown in \figref{method/locations}.
We considered five different positionings for providing the vibrotactile rendering as feedback of the contacts between the virtual hand and the \VOs, as shown in \figref{method/locations}.
They are representative of the most common locations used by wearable haptic devices in \AR to place their end-effector, as found in the literature (\secref[related_work]{vhar_haptics}), as well as other positionings that have been employed for manipulation tasks.
For each positioning, we used two vibrating actuators, for the thumb and index finger, respectively.
@@ -45,7 +45,7 @@ Similarly, we designed the distance vibration technique (Dist) so that interpene
\label{method}
This user study aims to evaluate whether a visuo-haptic rendering of the hand affects the user performance and experience of manipulation of \VOs with bare hands in \OST-\AR.
The chosen visuo-haptic hand renderings are the combination of the two most representative visual hand renderings established in the \chapref{visual_hand}, \ie \level{Skeleton} and \level{None}, described in \secref[visual_hand]{hands}, with the two contact vibration techniques provided at the four delocalized positions on the hand described in \secref{vibration}.
The chosen visuo-haptic hand renderings are the combination of the two most representative visual hand renderings established in the \chapref{visual_hand}, \ie \level{Skeleton} and \level{No Hand}, described in \secref[visual_hand]{hands}, with the two contact vibration techniques provided at the four delocalized positions on the hand described in \secref{vibration}.
\subsection{Experimental Design}
\label{design}
@@ -55,7 +55,7 @@ We considered the same two \level{Push} and \level{Grasp} tasks as described in
\begin{itemize}
\item \factor{Positioning}: the five positionings for providing vibrotactile hand rendering of the virtual contacts, as described in \secref{positioning}.
\item \factor{Vibration Technique}: the two contact vibration techniques, as described in \secref{technique}.
\item \factor{Hand}: two visual hand renderings from the first experiment, \level{Skeleton} (Skel) and \level{None}, as described in \secref[visual_hand]{hands}; we considered \level{Skeleton} as it performed the best in terms of performance and perceived effectiveness and \level{None} as reference.
\item \factor{Hand}: two visual hand renderings from the \chapref{visual_hand}, \level{Skeleton} (Skel) and \level{No Hand}, as described in \secref[visual_hand]{hands}; we considered \level{Skeleton} as it performed the best in terms of performance and perceived effectiveness and \level{No Hand} as reference.
\item \factor{Target}: we considered the target volumes (\figref{tasks}), from the participant's point of view, located at:
\begin{itemize}
\item left-bottom (\level{LB}) and left-right (\level{LF}) during the \level{Push} task; and
@@ -76,18 +76,18 @@ We considered the same two \level{Push} and \level{Grasp} tasks as described in
To account for learning and fatigue effects, the order of the \factor{Positioning} conditions were counter-balanced using a balanced \numproduct{10 x 10} Latin square.
In these ten blocks, all possible \factor{Technique} \x \factor{Hand} \x \factor{Target} combination conditions were repeated three times in a random order.
As we did not find any relevant effect of the order in which the tasks were performed in the first experiment, we fixed the order of the tasks: first, the \level{Push} task and then the \level{Grasp} task.
As we did not find any relevant effect of the order in which the tasks were performed in the \chapref{visual_hand}, we fixed the order of the tasks: first, the \level{Push} task and then the \level{Grasp} task.
This design led to a total of 5 vibrotactile positionings \x 2 vibration contact techniques \x 2 visual hand rendering \x (2 targets on the Push task + 4 targets on the Grasp task) \x 3 repetitions $=$ 420 trials per participant.
\subsection{Apparatus and Protocol}
\label{apparatus}
Apparatus and protocol were very similar to the first experiment, as described in \secref[visual_hand]{apparatus} and \secref[visual_hand]{protocol}, respectively.
Apparatus and protocol were very similar to the \chapref{visual_hand}, as described in \secref[visual_hand]{apparatus} and \secref[visual_hand]{protocol}, respectively.
We report here only the differences.
We employed the same vibrotactile device used by \cite{devigne2020power}.
It is composed of two encapsulated Eccentric Rotating Mass (ERM) vibration motors (Pico-Vibe 304-116, Precision Microdrive, UK).
It is composed of two encapsulated \ERM (\secref[related_work]{vibrotactile_actuators}) vibration motors (Pico-Vibe 304-116, Precision Microdrive, UK).
They are small and very light (\qty{5}{\mm} \x \qty{20}{\mm}, \qty{1.2}{\g}) actuators capable of vibration frequencies from \qtyrange{120}{285}{\Hz} and
amplitudes from \qtyrange{0.2}{1.15}{\g}.
They have a latency of \qty{20}{\ms} that we partially compensated for at the software level with slightly larger colliders to trigger the vibrations very close the moment the finger touched the cube.
@@ -127,7 +127,7 @@ Other expertise correlations were low ($r<0.35$).
\subsection{Collected Data}
\label{metrics}
During the experiment, we collected the same data as in the first experiment, see \secref[visual_hand]{metrics}.
During the experiment, we collected the same data as in the \chapref{visual_hand}, see \secref[visual_hand]{metrics}.
At the end of the experiment, participants were asked if they recognized the different contact vibration techniques.
They then rated the ten combinations of \factor{Positioning} \x \factor{Vibration Technique} using a 7-item Likert scale (1=Not at all, 7=Extremely):
\begin{itemize}