Multi-physics modelling and experimental validation of electrovibration based haptic devices

Electrovibration tactile displays exploit the polarisation of the finger pad, caused by an insulated high voltage supplied plate. This results in electrostatic attraction, which can be used to modulate the users' perception of an essentially flat surface and induce texture sensation. Two analytical models of electrovibration, based on parallel plate capacitor assumption, are demonstrably taken and assessed by comparisons with experimental results published in literature. In addition, an experimental setup was developed to measure the electrostatic force between the finger pad and a high voltage supplied plate in a static and out-of-contact state in order to support the use of parallel plate capacitor model. Development, validation, and application of a computational framework for modelling tactile scenarios on real and virtual surfaces rendered by electrovibration technique is presented. The framework incorporates fully parametric model in terms of materials and geometry of the finger pad, virtual and real surfaces, and can serve as a tool for virtual prototyping and haptic rendering in electrovibration tactile displays. This is achieved by controlling the applied voltage signal in order to guarantee similar lateral force cues in real and simulated surfaces

Electrovibration Signal Design : A Simulative Approach

International audienceElectrovibration technique can modify user's perception of a surface through the modulation of the sliding friction accordingly to the voltage applied. This paper is introducing a novel approach to virtual haptic rendering in electrovibration based haptic displays in order to provide realistic feeling of a simulated surface, where the required voltage signal is obtained using a simplified equation. The approach was validated by the use of a finite element computational framework able to simulate tactile scenarios on real and virtual surfaces. A database of pre-compiled tactile scenarios was generated to predict outputs for custom parametric surfaces through a conditional average estimator method. In addition, an experimental database obtained by active exploration of different surfaces, is utilised for texture rendering. A web application, comprising the algorithms described in the paper, has also been developed , and is freely available to use at http://www.haptictexture.com. Keywords: electrovibration · haptic rendering · finite element model · finger pad · virtual prototyping · haptic display · frictio