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Erwan Normand
2024-09-16 12:57:05 +02:00
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1-introduction/related-work/1-haptic-hand.tex
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@@ -94,7 +94,7 @@ As illustrated in the \figref{sensorimotor_continuum}, \Citeauthor{jones2006huma
]
This classification has been further refined by \textcite{bullock2013handcentric} into 15 categories of possible hand interactions with an object.
In this thesis, we are interested in exploring \vh augmentations (see \partref{perception}) and grasping of \VOs (see \partref{manipulation}) in the context of \AR and \WHs.
In this thesis, we are interested in exploring \vh augmentations (\partref{perception}) and grasping of \VOs (\partref{manipulation}) in the context of \AR and \WHs.
\subsubsection{Hand Anatomy and Motion}
\label{hand_anatomy}
@@ -143,8 +143,8 @@ It takes only \qtyrange{2}{3}{\s} to perform these procedures, except for contou
\subsubsection{Grasp Types}
\label{grasp_types}
Thanks to the degrees of freedom of its skeleton, the hand can take many postures to grasp an object (see \secref{hand_anatomy}).
By placing the thumb or palm against the other fingers (pad or palm grasps respectively), or by placing the fingers against each other as if holding a cigarette (side grasp), the hand can hold the object securely.
Thanks to the degrees of freedom of its skeleton, the hand can take many postures to grasp an object (\secref{hand_anatomy}).
By placing the thumb or palm against the other fingers (pad or palm opposition respectively), or by placing the fingers against each other as if holding a cigarette (side opposition), the hand can hold the object securely.
Grasping adapts to the shape of the object and the task to be performed, \eg grasping a pen with the fingertips then holding it to write, or taking a mug by the body to fill it and by the handle to drink it~\cite{cutkosky1986modeling}.
Three types of grasp are differentiated according to their degree of strength and precision.
In \emph{power grasps}, the object is held firmly and follows the movements of the hand rigidly.
@@ -154,7 +154,7 @@ In \emph{precision grasps}, the fingers can move the object within the hand but
For all possible objects and tasks, the number of grasp types can be reduced to 34 and classified as the taxonomy on \figref{gonzalez2014analysis}~\cite{gonzalez2014analysis}.\footnote{An updated taxonomy was then proposed by \textcite{feix2016grasp}: it is more complete but harder to present.}
For everyday objects, this number is even smaller, with between 5 and 10 grasp types depending on the activity~\cite{bullock2013grasp}.
Furthermore, the fingertips are the most involved areas of the hand, both in terms of frequency of use and time spent in contact: In particular, the thumb is almost always used, as well as the index and middle fingers, but the other fingers are used less frequently~\cite{gonzalez2014analysis}.
This can be explained by the sensitivity of the fingertips (see \secref{haptic_sense}) and the ease with which the thumb can be opposed to the index and middle fingers compared to the other fingers.
This can be explained by the sensitivity of the fingertips (\secref{haptic_sense}) and the ease with which the thumb can be opposed to the index and middle fingers compared to the other fingers.
\fig{gonzalez2014analysis}{Taxonomy of grasp types of~\textcite{gonzalez2014analysis}}[, classified according to their type (power, precision or intermediate) and the shape of the grasped object. Each grasp shows the area of the palm and fingers in contact with the object and the grasp with an example of object.]
@@ -162,7 +162,7 @@ This can be explained by the sensitivity of the fingertips (see \secref{haptic_s
\subsection{Haptic Perception of Object Properties}
\label{object_properties}
The active exploration of an object with the hand is performed as a sensorimotor loop: The exploratory movements (see \secref{exploratory_procedures}) guide the search for and adapt to sensory information (see \secref{haptic_sense}), allowing to construct a haptic perception of the object's properties.
The active exploration of an object with the hand is performed as a sensorimotor loop: The exploratory movements (\secref{exploratory_procedures}) guide the search for and adapt to sensory information (\secref{haptic_sense}), allowing to construct a haptic perception of the object's properties.
There are two main types of \emph{perceptual properties}.
The \emph{material properties} are the perception of the roughness, hardness, temperature and friction of the surface of the object~\cite{bergmanntiest2010tactual}.
The \emph{spatial properties} are the perception of the weight, shape and size of the object~\cite{lederman2009haptic}.
@@ -181,7 +181,7 @@ It is, for example, the perception of the fibers of fabric or wood and the textu
Roughness is what essentially characterises the perception of the \emph{texture} of the surface~\cite{hollins1993perceptual,baumgartner2013visual}.
When touching a surface in static touch, the asperities deform the skin and cause pressure sensations that allow a good perception of coarse roughness.
But when running the finger over the surface with a lateral movement (see \secref{exploratory_procedures}), vibrations are alos caused which give a better discrimination range and precision of roughness~\cite{bensmaia2005pacinian}.
But when running the finger over the surface with a lateral movement (\secref{exploratory_procedures}), vibrations are alos caused which give a better discrimination range and precision of roughness~\cite{bensmaia2005pacinian}.
In particular, when the asperities are smaller than \qty{0.1}{mm}, such as paper fibers, the pressure cues are no longer captured and only the movement, \ie the vibrations, can be used to detect the roughness~\cite{hollins2000evidence}.
This limit distinguishes \emph{macro-roughness} from \emph{micro-roughness}.
@@ -211,7 +211,7 @@ A larger spacing between elements increases the perceived roughness, but reaches
It is also possible to perceive the roughness of a surface by \emph{indirect touch}, with a tool held in the hand, for example by writing with a pen on paper~\cite{klatzky2003feeling}.
The skin is no longer deformed and only the vibrations of the tool are transmitted.
But this information is sufficient to feel the roughness, which perceived intensity follows the same quadratic law.
The intensity peak varies with the size of the contact surface of the tool, \eg a small tool allows to perceive finer spaces between the elements than with the finger (see \figref{klatzky2003feeling_2}).
The intensity peak varies with the size of the contact surface of the tool, \eg a small tool allows to perceive finer spaces between the elements than with the finger (\figref{klatzky2003feeling_2}).
However, as the speed of exploration changes the transmitted vibrations, a faster speed shifts the perceived intensity peak slightly to the right, \ie decreasing perceived roughness for fine spacings and increasing it for large spacings~\cite{klatzky2003feeling}.
\begin{subfigs}{klatzky2003feeling}{Estimation of haptic roughness of a surface of conical micro-elements by active exploration~\cite{klatzky2003feeling}. }[
@@ -248,7 +248,7 @@ The perceived softness of a fruit allows us to judge its ripeness, while ceramic
By tapping on a surface, metal will be perceived as harder than wood.
If the surface returns to its original shape after being deformed, the object is elastic (like a spring), otherwise it is plastic (like clay).
When the finger presses on an object (see \figref{exploratory_procedures}), its surface will move and deform with some resistance, and the contact area of the skin will also expand, changing the pressure distribution.
When the finger presses on an object (\figref{exploratory_procedures}), its surface will move and deform with some resistance, and the contact area of the skin will also expand, changing the pressure distribution.
When the surface is touched or tapped, vibrations are also transmitted to the skin.
Passive touch (without voluntary hand movements) and tapping allow a perception of hardness as good as active touch~\cite{friedman2008magnitude}.
@@ -290,7 +290,7 @@ Friction (or slipperiness) is the perception of \emph{resistance to movement} on
Sandpaper is typically perceived as sticky because it has a strong resistance to sliding on its surface, while glass is perceived as more slippery.
This perceptual property is closely related to the perception of roughness~\cite{hollins1993perceptual,baumgartner2013visual}.
When running the finger on a surface with a lateral movement (see \secref{exploratory_procedures}), the skin-surface contacts generate frictional forces in the opposite direction to the finger movement, giving kinesthetic cues, and also stretch the skin, giving cutaneous cues.
When running the finger on a surface with a lateral movement (\secref{exploratory_procedures}), the skin-surface contacts generate frictional forces in the opposite direction to the finger movement, giving kinesthetic cues, and also stretch the skin, giving cutaneous cues.
As illustrated in \figref{smith1996subjective_1}, a stick-slip phenomenon can also occur, where the finger is intermittently slowed by friction before continuing to move, on both rough and smooth surfaces~\cite{derler2013stick}.
The amplitude of the frictional force $F_s$ is proportional to the normal force of the finger $F_n$, \ie the force perpendicular to the surface, according to a coefficient of friction $\mu$:
\begin{equation}
@@ -340,7 +340,7 @@ For example, a larger object or a smoother surface, which increases the contact
Weight, size and shape are haptic spatial properties that are independent of the material properties described above.
Weight (or heaviness/lightness) is the perceived \emph{mass} of the object~\cite{bergmanntiest2010haptic}.
It is typically estimated by holding the object statically in the palm of the hand to feel the gravitational force (see \secref{exploratory_procedures}).
It is typically estimated by holding the object statically in the palm of the hand to feel the gravitational force (\secref{exploratory_procedures}).
A relative weight difference of \percent{8} is then required to be perceptible~\cite{brodie1985jiggling}.
By lifting the object, it is also possible to feel the object's force of inertia, \ie its resistance to velocity.
This provides an additional perceptual cue to its mass and slightly improves weight discrimination.
@@ -348,15 +348,15 @@ For both gravity and inertia, kinesthetic cues to force are much more important
%Le lien entre le poids physique et l'intensité perçue est variable selon les individus~\cite{kappers2013haptic}.
Size can be perceived as the object's \emph{length} (in one dimension) or its \emph{volume} (in three dimensions)~\cite{kappers2013haptic}.
In both cases, and if the object is small enough, a precision grip (see \figref{gonzalez2014analysis}) between the thumb and index finger can discriminate between sizes with an accuracy of \qty{1}{\mm}, but with an overestimation of length (power law with exponent \qty{1.3}).
Alternatively, it is necessary to follow the contours of the object with the fingers to estimate its length (see \secref{exploratory_procedures}), but with ten times less accuracy and an underestimation of length (power law with an exponent of \qty{0.9})~\cite{bergmanntiest2011cutaneous}.
In both cases, and if the object is small enough, a precision grip (\figref{gonzalez2014analysis}) between the thumb and index finger can discriminate between sizes with an accuracy of \qty{1}{\mm}, but with an overestimation of length (power law with exponent \qty{1.3}).
Alternatively, it is necessary to follow the contours of the object with the fingers to estimate its length (\secref{exploratory_procedures}), but with ten times less accuracy and an underestimation of length (power law with an exponent of \qty{0.9})~\cite{bergmanntiest2011cutaneous}.
The perception of the volume of an object that is not small is typically done by hand enclosure, but the estimate is strongly influenced by the size, shape and mass of the object, for an identical volume~\cite{kahrimanovic2010haptic}.
The shape of an object can be defined as the perception of its \emph{global geometry}, \ie its shape and contours.
This is the case, for example, when looking for a key in a pocket.
The exploration of contours and enclosure are then employed, as for the estimation of length and volume.
If the object is not known in advance, object identification is rather slow, taking several seconds~\cite{norman2004visual}.
Therefore, the exploration of other properties is favoured to recognize the object more quickly, in particular marked edges~\cite{klatzky1987there}, \eg a screw among nails (see \figref{plaisier2009salient_2}), or certain material properties~\cite{lakatos1999haptic,plaisier2009salient}, \eg a metal object among plastic objects.
Therefore, the exploration of other properties is favoured to recognize the object more quickly, in particular marked edges~\cite{klatzky1987there}, \eg a screw among nails (\figref{plaisier2009salient_2}), or certain material properties~\cite{lakatos1999haptic,plaisier2009salient}, \eg a metal object among plastic objects.
\begin{subfigs}{plaisier2009salient}{Identifcation of a sphere among cubes~\cite{plaisier2009salient}. }[
\item The shape has a significant effect on the perception of the volume of an object, \eg a sphere is perceived smaller than a cube of the same volume.