Simulating Haptic Feedback Using Vision: A Survey of Research and Applications of Pseudo-Haptic Feedback

Anatole Lécuyer
2009 Presence - Teleoperators and Virtual Environments  
This paper presents a survey of the main results obtained in the field of "pseudo-haptic feedback": a technique meant to simulate haptic sensations in virtual environments using visual feedback and properties of human visuo-haptic perception. Pseudo-haptic feedback uses vision to distort haptic perception and verges on haptic illusions. Pseudo-haptic feedback has been used to simulate various haptic properties such as the stiffness of a virtual spring, the texture of an image, or the mass of a
more » ... irtual object. This paper describes the several experiments in which these haptic properties were simulated. It assesses the definition and the properties of pseudo-haptic feedback. It also describes several virtual reality applications in which pseudo-haptic feedback has been successfully implemented, such as a virtual environment for vocational training of milling machine operations, or a medical simulator for training in regional anesthesia procedures. make the object move through the passage gives the user an impression of resistance and friction, despite the fact he/she is not using a haptic interface. This type of perceived effect, which in this example creates the impression of friction, has been named "Pseudo-haptic feedback" (Lécuyer, Coquillart, Kheddar, Richard, & Coiffet, 2000). In a way, the user generates and controls the force feedback himself/herself by increasing or decreasing the pressure on the static device. Pseudo-haptic feedback has been the focus of many experiments that have simulated various haptic properties such as friction, stiffness, or texture of virtual objects. In this paper, we will begin by 1 A Spaceball is an isometric input interface. Zhai (Zhai, 1995) classified the input devices into two categories: isometric devices which are static, offer resistance and stay put while you exert force on them; and isotonic devices which offer no significant resistance and are used to track users as they move around. A Spaceball features force sensors that measure compression or torsion efforts applied to it. These forces can then be used to move 3D objects in virtual reality simulations. Today, these interfaces are widely used in the world of CAD: Computer Aided Design. 4 introducing related work in the field of visuo-haptic integration and haptic illusions. Then we will give the founding ideas of the concept of pseudo-haptic feedback. We will then review the several haptic properties that have been simulated to date using pseudo-haptic feedback. Next, we will assess the potential applications of pseudo-haptic feedback in virtual reality. Finally, we will draw lessons from past experiences in implementing and evaluating pseudo-haptic systems. VISUO-HAPTIC INTEGRATION AND HAPTIC ILLUSIONS The endeavor to understand the mechanisms behind visuo-haptic integration has formed the subject of on-going debates for over a century and are still very much unresolved. To date, several models for multimodal perception and visuo-haptic integration have been put forward (Cornilleau-). As an example, Ernst and Banks proposed a statistical model for visuo-haptic integration, which was backed up by psychophysical experiments (Ernst & Banks, 2002) . This model stipulates that the weight attributed to visual and haptic information is related to the independent performance of each of the two sensory channels (unimodal performance). The experiment conducted by Ernst and Banks to validate their model involved estimating a spatial parameter: the length of a side of a cube. By reducing the sharpness of the cube's visual contour (i.e. by adding noise to the cube's visual feedback), they observed that the weight attributed to vision by the perceptive system was reduced in proportion to the degradation in visual performance. In this way, the researchers demonstrated that the greater the efficiency of a sense in measuring a property, the more the perceptive system will make use of that sense when perceiving that property. To study the weight attributed to visual and haptic information by human perception, researchers tend to use tasks that create sensory conflicts. A sensory conflict implies that the haptic information simulated in
doi:10.1162/pres.18.1.39 fatcat:wnp346d4w5djvnx7yhloazn7c4