La télévision n’a cessé de se populariser et d’évoluer en proposant de nouveaux services. Ces services de plus en plus interactifs rendent les téléspectateurs plus engagés dans l’activité télévisuelle. Contrairement à l’usage d’un ordinateur, ils interagissent sur un écran distant avec une télécommande et des applications depuis leur canapé peu propice à l’usage d’un clavier et d’une souris. Ce dispositif et les techniques d’interaction actuelles qui lui sont associées peinent à répondre correctement à leurs attentes. Afin de répondre à cette problématique, les travaux de cette thèse explorent les possibilités offertes par la modalité gestuelle pour concevoir de nouvelles techniques d’interaction pour la télévision interactive en tenant compte de son contexte d’usage.
Dans un premier temps, nous présentons le contexte singulier de l’activité télévisuelle. Puis, nous proposons un espace de caractérisation des travaux de la littérature cherchant à améliorer la télécommande pour, finalement, nous focaliser sur l’interaction gestuelle. Nous introduisons un espace de caractérisation qui tente d’unifier l’interaction gestuelle contrainte par une surface, mains libres, et instrumentée ou non afin de guider la conception de nouvelles techniques. Nous avons conçu et évalué diverses techniques d’interaction gestuelle selon deux axes de recherche : les techniques d’interaction gestuelle instrumentées permettant d’améliorer l’expressivité interactionnelle de la télécommande traditionnelle, et les techniques d’interaction gestuelles mains libres en explorant la possibilité de réaliser des gestes sur la surface du ventre pour contrôler sa télévision. / Television has never stopped being popularized and offering new services to the viewers. These interactive services make viewers more engaged in television activities. Unlike the use of a computer, they interact on a remote screen with a remote control from their sofa which is not convenient for using a keyboard and a mouse. The remote control and the current interaction techniques associated with it are struggling to meet viewers’ expectations. To address this problem, the work of this thesis explores the possibilities offered by the gestural modality to design new interaction techniques for interactive television, taking into account its context of use.
More specifically, in a first step, we present the specific context of the television usage. Then, we propose a litterature review of research trying to improve the remote control. Finally we focus on gestural interaction. To guide the design of interaction techniques based on gestural modality, we introduce a taxonomy that attempts to unify gesture interaction constrained by a surface and hand-free gesture interaction.
Therefore, we propose various techniques for gestural interaction in two scopes of research : gestural instrumented interaction techniques, which improves the traditional remote control expressiveness, and hand-free gestural interaction by exploring the possibility o performing gestures on the surface of the belly to control the television set.

Robot motion can be described in several alternative representations, including joint configuration or end-effector spaces. These representations are often used for manipulation or navigation tasks but they are not suitable for tasks that involve close interaction with the environment. In these scenarios, collisions and relative poses of the robot and its surroundings create a complex planning space. To deal with this complexity, we exploit several representations that capture the state of the interaction, rather than the state of the robot. Borrowing notions of topology invariances and homotopy classes, we design task spaces based on winding numbers and writhe for synthesizing winding motion, and electro-static fields for planning reaching and grasping motion. Our experiments show that these representations capture the motion, preserving its qualitative properties, while generalising over finer geometrical detail. Based on the same motivation, we utilise a scale and rotation invariant representation for locally preserving distances, called interaction mesh. The interaction mesh allows for transferring motion between robots of different scales (motion re-targeting), between humans and robots (teleoperation) and between different environments (motion adaptation). To estimate the state of the environment we employ real-time sensing techniques utilizing dense stereo tracking, magnetic tracking sensors and inertia measurements units. We combine and exploit these representations for synthesis and generalization of motion in dynamic environments. The benefit of this method is on problems where direct planning in joint space is extremely hard whereas local optimal control exploiting topology and metric of these novel representations can efficiently compute optimal trajectories. We formulate this approach in the framework of optimal control as an approximate inference problem. This allows for consistent combination of multiple task spaces (e.g. end-effector, joint space and the abstract task spaces we investigate in this thesis). Motion generalization to novel situations and kinematics is similarly performed by projecting motion from abstract representations to joint configuration space. This technique, based on operational space control, allows us to adapt the motion in real time. This process of real-time re-mapping generates robust motion, thus reducing the amount of re-planning. We have implemented our approach as a part of an open source project called the Extensible Optimisation library (EXOTica). This software allows for defining motion synthesis problems by combining task representations and presenting this problem to various motion planners using a common interface. Using EXOTica, we perform comparisons between different representations and different planners to validate that these representations truly improve the motion planning.