Haptic Feedback (Haptic Technology)

Historical Story

When Arthur Lessac showed up for the first day of his indus­trial design course, he was surprised to see so much computer hardware in the lab. He had used CAD pro­grams and modeling tools in other design courses, but this lab was full of Haptic Devices that the students would use in designing anything from electric tooth­brushes and gardening tools to office furniture and exercise equipment. Arthur decided to design a chair suitable for cafés or coffee shops. He wanted his chair to be comfortable but also easy to move and store on occasions when, for example, a coffee shop hosted a poetry reading or live music.

Arthur Lessac (Died at his 101 age)

Arthur used a Haptic Device that simulated textures to test different choices for the seat and backrest materi­als. He could "build" a virtual version of his chair with a deep cushion and suede fabric, or a thin layer of foam covered with slightly stretchy nylon, or simply a molded piece of plastic. Sliding his hand into a small Haptic Sleeve connected to a computer interface, Arthur could run his fingers along the surface of his Virtual Chair and press against it as he watched an animation of the chair on a monitor. The Haptic Device simulated the textures and firmness of the different material choices, transmitting those sensations to Arthur's hand.

Haptic Virtual Chair

Arthur wanted his chairs to stack easily and be light enough to comfortably slide across a floor. With the Haptic Design Tools, Arthur could choose from various materials to construct his chair, and, using a two-hand­ed controller, he could "pick up" his Virtual Chair and feel for himself how heavy it was. The choice of materi­als and the design of the mating surfaces affected how easily the chairs could be stacked and unstacked, and Arthur could feel these differences through the Haptic Controller. He could choose different flooring materi­als and simulate pushing a stack of chairs, feeling the varying resistance through the controller.

About Haptic Feedback Definition :

Haptic Feedback, or haptics, is a tactile feedback technology which takes advantage of the human Sense of Touch by applying forces, vibrations, or motions to the user to give a Feeling of Realism on Touch Screens or Video Games through a Haptic Device or Interface and there are two Types of Haptic Feedback which are Tactile Feedback and Force Feedback.

Haptic Feedback Virtual Button

Haptic Feedback on Touch Screens is a process which involves for example sending a small electrical impulse in the user's finger on the screen to give the impression that the screen is not always flat, but in volume! This allows to give a feeling of relief to the Virtual Buttons.

Haptics is a recent enhancement to virtual environments allowing users to "touch" and feel the simulated objects with which they interact. Haptics is the Science of Touch. The word derives from the Greek haptikos meaning "being able to come into contact with". The Study of Haptics emerged from advances in Virtual Reality. Virtual Reality is a form of human-computer interaction (as opposed to keyboard, mouse and monitor) providing a virtual environment that one can explore through direct interaction with our senses. To be able to interact with an environment, there must be feedback. For example, the user should be able to touch a virtual object and feel a response from it. This type of feedback is called Haptic Feedback. 

Haptic Touch Technology has made it possible to investigate how the human Sense of Touch works by allowing the creation of carefully controlled haptic virtual objects. These objects are used to systematically probe human haptic capabilities, which would otherwise be difficult to achieve. These research tools contribute to the understanding of how touch and its underlying brain functions work.

• Future of Haptic Feedback Technology

  The interface between humans and computers has been de­scribed as an information bottleneck. Computers can store and process vast amounts of data, and humans experience and learn through five senses. But computers typically only take advantage of one or two sensory channels (sight and sound) to transmit information to people. Haptics promises to open this bottleneck by adding a new channel of communication using the Sense of Touch. Haptic Feedback expands the notion of bidirectional communication between humans and computers to include sensory feedback.
  
  

  

  Future of Haptic Technology

  
  Active learning strategies result in stronger comprehension of sub­jects, and haptics provides a mechanism through which students can actively engage in learning a range of ideas and skills, putting control of learning literally into their hands. Haptic Feedback also has a growing role in Assistive Technologies. The haptic mouse, for instance, provides sensory feedback that allows users with visual impairments to "read" a computer screen by feeling buttons and other elements. Such devices can also benefit users without disabilities but who are tactile or kinesthetic learners.
  
  

  

  What the world is waiting for?

  
  Development and refining of various kinds of Haptic Interfaces will continue, providing more and increasingly lifelike interactions with virtual objects and environments. Researchers will continue to in­vestigate possible avenues for haptics to complement real experi­ences. Advances in hardware will provide opportunities to produce Haptic Devices in smaller packages, and Haptic Technology will find its way into increasingly commonplace tools. Additionally, con­sumer-grade haptic devices are starting to appear on the market. As access to haptics increases, usage patterns and preferences will inform best practices and applications ultimately, users will decide which activities are appropriately represented through Hap­tics and which are perhaps better left in the real world.

• What is the Haptic Device or Interface?

  Haptic Devices (or Haptic Interfaces) are mechanical devices that mediate communication between the user and the computer. Haptic Devices allow users to touch, feel and manipulate three-dimensional objects in virtual environments and tele-operated systems. General-purpose commercial haptic interfaces used today can be classified as either Ground-Based Devices (force reflecting joysticks and linkage-based devices) or Body-Based Devices (gloves, suits, exoskeletal devices).
  
  

  

  Example of a Haptic Device

  
  Most common computer interface devices, such as basic mice and joysticks, are input-only devices, meaning that they track a user's physical manipulations but provide no Manual Feedback. As a result, information flows in only one direction, from the peripheral to the computer. Haptic Devices are input-output devices, meaning that they track a user's physical manipulations (input) and provide realistic Touch Sensations coordinated with on-screen events (output). Examples of Haptic Devices include consumer peripheral devices equipped with special motors and sensors (e.g., Force Feedback joysticks and steering wheels) and more sophisticated devices designed for industrial, medical or scientific applications (e.g. Phantom Arm Device).
  
  

  

  Phantom Arm

  
  Haptic Interfaces are relatively sophisticated devices. As a user manipulates the end effector, grip or handle on a Haptic Device, encoder output is transmitted to an interface controller at very high rates. Here the information is processed to determine the position of the end effector. The position is then sent to the host computer running a supporting software application. If the supporting software determines that a reaction force is required, the host computer sends feedback forces to the device. Actuators (motors within the device) apply these forces based on mathematical models that simulate the desired sensations. For example, when simulating the feel of a rigid wall with a Force Feedback joystick, motors within the joystick apply forces that simulate the feel of encountering the wall. As the user moves the joystick to penetrate the wall, the motors apply a force that resists the penetration. The farther the user penetrates the wall, the harder the motors push back to force the joystick back to the wall surface. The end result is a sensation that feels like a physical encounter with an obstacle.
  
  

  

  Two Haptic Interfaces used at the same time

  
  The Human Sensorial Characteristics impose much faster refresh rates for Haptic Feedback than for Visual Feedback. Computer Graphics has for many years contended itself with low scene refresh rates of 20 to 30 frames/sec. In contrast, tactile sensors in the skin respond best to vibrations higher that 300 Hz. This order-of-magnitude difference between haptics and vision bandwidths requires that the Haptic Interface incorporate a dedicated controller. Because it is computationally expensive to convert encoder data to end effector position and translate motor torques into directional forces, a Haptic Device will usually have its own dedicated processor. This removes computation costs associated with haptics and the host computer can dedicate its processing power to application requirements, such as rendering high-level graphics.

  

• How is Haptic Technology in Video Games

  Game designers are constantly seeking new ways to increase the realism of the player's experience, a way of doing this is allowing players to use their Sense of Touch through a peripheral device such as a control, to play the game. This technology allows players to use their Sense of Touch and is called Haptic Technology.
  
  

  

  Haptic Feedback in Video Games

  
  The haptic is the study of how to couple the human Sense of Touch with a computer-generated world. And there are two Types of Haptic Feedback.
  
  User Experience Enhancement in Video Games
  
  

  

  Haptic Devices in Video Games

   
  Haptic Feedback can enhance the user experience in Video Games by using Haptic Devices for example, through these three points :
  

  1. Improved Usability : By restoring the sense of touch to otherwise flat, cold surfaces, haptics creates fulfilling multi-modal experiences that improve usability by engaging touch, sight and sound.  From the confidence a user receives through touch confirmation when selecting a virtual button to the contextual awareness they receive through haptics in a first person shooter game, haptics improves usability by more fully engaging the user’s senses.
  2. Enhanced Realism : Haptics injects a sense of realism into user experiences by exciting the senses and allowing the user to feel the action and nuance of the application. This is particularly relevant in applications like games or simulation that rely on only visual and audio inputs. The inclusion of tactile feedback provides additional context that translates into a sense of realism for the user.
  3. Restoration of Mechanical Feel :  Today’s touchscreen-driven devices lack the physical feedback that humans frequently need to fully understand the context of their interactions.  By providing users with intuitive and unmistakable tactile confirmation, haptics can create a more confident user experience and can also improve safety by overcoming distractions. This is especially important when audio or visual confirmation is insufficient, such as industrial applications, or applications that involve distractions, such as automotive navigation.

  
  Examples of using Haptic Feedback in Video Games
  
  

  

  Microsoft Flight Simulator

  
  In video games Haptic Feedback usually originates in the control of the game or in a wheel. All Haptic Devices are derived from a convergence of mechanical and electrical engineering and software.
  
  For example, Microsoft Flight Simulator, players can feel the butt of the gun, the damage from weapons fire and explosions. Another example is the game "Need for Speed", where players can feel the centripetal forces in the steering wheel, dynamically changing the speed in the turns. In the game "Metal Gear Solid" effects added tactile designers to help create certain moods or environments, for example, when a helicopter flying low-passes overhead, the player can feel a rumbling in the land that gradually intensifies and finally disappears.
  
  The use of Haptic Feedback has been growing and improving, allowing games to be increasingly realistic. To have all these technologies in a game, you need to develop all the code that will create the ultimate video game.

  

• What are the Types of Haptic Feedback?

  There are two types of Haptic Feedback, In human-computer interaction, Haptic Feedback means both Tactile Feedback and Force Feedback. Tactile, or Touch Feedback is the term applied to sensations felt by the skin. Tactile feedback allows users to feel things such as the texture of surfaces, temperature and vibration. Force feedback reproduces directional forces that can result from solid boundaries, the weight of grasped virtual objects, mechanical compliance of an object and inertia.
  
  
  

  

  Haptics

  
  

  Force Feedback (Kinesthetic) 

  It is the area that deals with Haptic Devices that interact with the muscles and tendons which produces the sensation of force application on the player. These devices consist mainly of robotic manipulators applying forces pushing against the user corresponding to the environment in which there is the "effector" device used to produce a desired change in an object in response to a given command.
  
  Scientists have been conducting research on haptics for decades. Goertz at Argonne National Laboratories first used Force Feedback in a robotic tele-operation system for nuclear environments in 1954. Subsequently the group led by Brooks at the University of North Carolina at Chapel Hill adapted the same electromechanical arm to provide force feedback during virtual molecular docking (1990). Burdea and colleagues at Rutgers University developed a light and portable force feedback glove called the "Rutgers Master" in 1992. Commercial force feedback devices have subsequently appeared, such as the Phantom Arm in 1993, the Impulse Engine in 1995 and the CyberGrasp Glove in 1998.
  

  Tactile Feedback (Touch)  

  It deals with devices (control of the game or wheel) that interact with the nerve endings in the skin that feel heat, pressure and texture. These devices typically are used to indicate whether the user is or is not in contact with a virtual object. Other tactile feedback devices have been used to simulate textures in Virtual Objects.

  Tactile Feedback, as a component of virtual reality simulations, was pioneered at MIT. In 1990 Patrick used voice coils to provide vibrations at the fingertips of a user wearing a Dextrous Hand Master Exoskeleton. Minsky and her colleagues developed the Sandpaper Tactile Joystick that mapped image texels to vibrations (1990). Commercial tactile feedback interfaces followed, namely the "Touch Master" in 1993, the CyberTouch Glove in 1995, and more recently, the "FEELit Mouse" in 1997.

  

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  Haptic Feedback illusions

  Just as there are optical illusions, there are Haptic illusions. It is possible initially to play on the fact that the haptic is rarely used alone (like the other senses). Thus when the information is conflicting, most people unconsciously give reason for their view, then to the touch. An experiment conducted by Srinivasan, Beauregard, and Brock in 1996 in MIT has demonstrated the preeminence of sight compared to the Sense of Touch and there were two springs displayed on screen and felt by the user via a Haptic Device.
  
  

  

  Haptic Feedback illusions

  
  The latter would then indicate, based on two types of information available, which was the most resistant springs. In the absence of visual aid users just met most of the time. But with a visual aid adversarial users were wrong in almost 100% of cases. This Visual Capture must be tempered, however, because of properties such as texture where the Haptic Feedback is "Owning" that is to say extremely successful compared to the vision, and under certain conditions it can highlight a Haptic Capture. Ernst and Banks (2002) modeled the situations of conflict between vision and haptics with a Bayesian formalization and showed a Haptic Capture of Perceptual System when it was probabilistically the most efficient for detecting the width of an object.
  
  Geometric Illusions are not all present in the haptic. Indeed, the Muller-Lyer illusion is observed in the haptic modality, with a similar intensity in adults working without seeing and late blind (having visual experience) and even in congenitally blind (without any visual experience). Three factors are responsible for the presence of the Muller-Lyer illusion and its intensity changes in vision and haptics:
  

  1. Repetition with an illusion which decreases as the number of presentations of the figure increase.
  2. Angle with an illusion that is even stronger than the acute angle formed by pennures and the segment to be evaluated is small.
  3. Instructions with an illusion that disappears when participants are asked to ignore pennures and use their body as a spatial reference.

  However, the illusions of the Titchner type exist only in the vision. These results show that the Haptic Sense is sometimes sensitive and sometimes less sensitive than the vision of Perceptual illusions. It seems to be that a sense is a little less "misleading" the vision.
  
  It is thus possible to create a shape illusion of a (3D) object by exerting forces on a flat surface. "This illusion is the demonstration of the mental representation that is a stimulus. A force applied in one dimension, can be much more elaborate and perceived in three dimensions." says researcher Vincent Hayward at McGill University (Canada). And to create the impression of a bump there will be applied increasing pressure, reverse the movement of the user, during the rise, then a force in the direction of motion during the descent.

  Sense of Touch and Haptic Sensations

• Haptic Feedback is studying the Sense of Touch, in the broadest sense. We can decompose our interaction with objects through our hand, for example, as below:
  
  

  

  Sense of Touch

  
  Actually, in Haptic Feedback we have three types of Haptic Sensations to feel with our Sense of Touch and that is why we call that technology as the Science of Touch.
  
  Kinesthetic (Force) Sense :
  
  

  

  Motor System

  
  It is the feeling of power and force. Our motor system constantly informs us about the position of our arms, and the efforts we make to move them. When we make an effort but that does not move our arms, we have a feeling of strength. This is not the case if we support our arm with a table.
  
  Tactile (Touch) Sense :
  
  

  

  Touch Sense

  
  This is the sensation of textures. At our fingertips (and more broadly on our skin), we have pressure sensors which gives us information on the relief of the object. This is what allows us to easily differentiate a smooth object of a rugeux object, for example. 
  
  

  Temperature (Thermal) Sense :

  
  

  

  Temperature Sense

  
  It is the senstation of cold or heat. This sensation tells us about two points: First, the temperature of the relative object to our finger (when our finger is cold, warmer objects appear to us).  Second, the nature of the object. Even if a piece of wood and a piece of metal are at the same temperature, we perceive them differently. For us, the metal is more "cold" than wood.
  
  The multiple meanings are still poorly understood, for example, what is our ability to distinguish objects only by their thermal characteristics? Is the vision more or less important than what we feel with our fingers to know something? These aspects also involve the Study of Human, in order to indentify our strengths and weaknesses in the Sense of Touch, which allows to exploit them (e.g. using Haptic Feedback illusions).