Sylvain Cardin
Surrounding environment is mainly perceived through sight and hearing. Our sense of touch is mostly dedicated to explore the surface of objects using hands and fingers. Tactile sensitivity of the body skin is rather limited in common life, however this represents a viable channel to pass information. The goal of this thesis is to study the added value of tactile stimulation to increase perception in specific application contexts. First, we define our motivation and approach regarding existing tactile systems and scientific knowledge available. In order to study tactile influence in different applications, we decided to build our own hardware and software blocks based on vibrotactile actuators driven by embedded electronics communicating with an external computer. Our objective was to explore different research directions by assessing added value in term of perception for tactile stimulation. The first topic we study tends to replace one of our senses, sight, by a metaphorical vibrotactile feedback representing the distance to close range object. We developed an electronic travel aid for visually impaired people, based on vibration motors and sonar. We assessed its ability to evolve and avoid obstacles in our surrounding environment. The next step consists in determining if such a principle can be applied to pass information about the environment within the field of teleoperation. Indeed, controlling a distant unmanned aerial vehicle is a difficult task due to limited visual feedback and absence of proprioceptive cue to feel the motion of the aircraft. Applying vibrotactile feedback that represents the effect of the wind seems to be an interesting approach for mental perception of the behavior of a remote controlled blimp. Wind is a natural phenomenon that we feel through our somatosensory system. At this point we wondered about the need of a metaphorical representation using vibrotactile stimulation. Even if it is rather easy to recreate wind using a fan, there is a lack of proper hardware to recreate directional wind. We built the first "wearable" haptic wind device for virtual reality enhancement and proved its usability to pass relevant directional information. Giving a direction in 3D space requires that the actuators are not located on the same plane as in our previous systems. We developed a wireless vibrotactile jacket containing 32 vibration motors and present its added value for a 3D searching space exercise in virtual environment, in correlation with visual and auditory cues. The second half of this document treats about development and application of a vibrotactile system in the challenging "Solar Impulse" project, aiming at performing a flight around the world relying only on renewable energy. A prototype aircraft has been built pushing forward the limits of the feasible in solar energy, composite materials, power management and human factor. As scientific consultant, our mission was to build an intelligent jacket in order to achieve symbodic relation between man and machine. A Symbodic system (SYMbiotic BODies) is a wearable device that supports symbiotic communication between the bodies of the pilot and of the machine. We proposed then a promising concept on how to improve awareness of the aircraft behavior. Passing from research concept to a concrete flying prototype is not an easy task, especially in terms of end-user acceptance: habits are strong for experienced pilot. But such an extraordinary airplane leads to some extraordinary aerodynamical behavior and the need of new visualization instruments. We developed an alert system for long flight duration based on the principle of the rumble strip installed on side of worldwide motor ways. Extensive tests have been performed by putting a subject in command of a highly realistic flight simulator for 48 hours straight. We showed that such system produces significant improvements of piloting performance under heavy sleep deprivation constraints.
EPFL2010
