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HapticMED – Key Concepts
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1. Haptic Feedback
 

The root of the word „haptic” comes from the greek language „haptesthai” and it means to touch. Haptics research studies the simulation of the tactile sensation in computer applications for simulation and training in various branches of industry. This mode of interaction with the computer allows simulation of tactile sensations through a haptic device attached as a terminal to the computer. Combining the visual (the image on the monitor) with the tactile (the touch sensation given by the haptic system) has the potential of creating very efficient simulators which can enhance the simulation and the training efficiency.

 

 2. Haptic Devices
 
The haptic devices apply relative small forces upon the user (generally on the user’s hands) through a complex system of servoengines and mechanical links. There are four natural methods of tactile exploration each of which is based on different characteristics of the explored object:

·         Stroking gives us information about the texture of the objects.

·         Pressure gives us information about the rigidity of the material from which the object is made.

·         Touching the edge of the object gives us information about the shape of the object.

·         Enclosure of the object gives us information about dimension or volume.

 

There are numerous haptic devices on the market and their price has dropped significantly over the past years due to their applicability and production on an industrial scale. We mentioned in an earlier paragraph PHANTOM® Omni™ (Figure 1a), a device which can apply forces through a mechanical joint (in the shape of a pencil which can be used naturally). The haptic gloves (Figure 1b), allow the user to feel the shape of virtual objects. In autumn 2007, Novint, a company founded by the researchers of Sandia National Laboratory, marketed the very first commercial haptic device  with 3D manipulation. Falcon Novint (Figure 1c) has been on the market on a big scale and at a very low price in conjunction with computer games, in USA, Asia and Australia [Falcon, 2008].
 

These devices represent decades of R&D in hardware and software, however their working principles are relatively simple. They are based on point interaction as presented in Figure 2.
 
 
When the user acts on the sphere in the real world (Figure 2 - left), the corresponding virtual point can collide with other virtual objects (Figure 2 - right). The collision information (the vectors which represent the forces) is computed and sent back to the servoengines of the device blocking the hand of the user and giving the feel of touch or haptic feedback (tactile)
 
 
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