Haptic - A Tactile Feedback Technology An Overview

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1 Haptic - A Tactile Feedback Technology An Overview Payal Mathur 1, Mragank Singhal 2, Shambhu Bhardwaj 3 1 College of Computing Sciences and Information Technology Teerthanker Mahaveer University, Moradabad 1 payalmathur2010@gmail.com 2 mraganksinghal@gmail.com 3 shambhu.bhardwaj@gmail.com Abstract As the technology advances in the past few years, computer technology is making its way to the general public at an affordable price such as a faster CPU, a larger hard drive, better graphic card, better multimedia system, and better computer tools. One of these computer technologies that is finding its way to the home and business PC market is the Haptic Technology, a fairly recent enhancement to virtual reality technology. Until recently, most computer-based simulations of objects were visual. The user might look at a computer screen to see an object. There might also be some sound to improve the display. One key element that is missing is the ability to feel the object, to get a sense of how heavy it is, what it is made of, or its surface texture. Haptic technologies try to solve this problem. Haptic Technology can be described as for the sense of touch as what the computer graphics does for vision [1]. Haptic permits users to sense or feel and manipulate three-dimensional virtual objects with respect to features such as shape, weight, surface textures and temperature. By using Haptic devices, the user can not only feed information to the computer but can receive information from the computer in the form of a felt sensation on some part of the body. This is referred to as a Haptic Interface. This paper describes the basic concepts of Haptic Technology, background to haptic, some of the haptic devices, various applications of haptic technology and some of the future possibilities of the haptic devices along with the advantages and disadvantages of Haptic technology. "mind" of the computer. These interactions might be as simple as touching a virtual wall or button, or as complex as performing a critical procedure in a surgical operation [2]. The term "haptic" has been used for years by researchers in human psychophysics who study how people use their hands to sense and manipulate objects. To sense the shape of a cup we do not take a simple tactile snapshot and go away to think about what we felt. Rather, we grasp and manipulate the object, running our fingers across its shape and surfaces in order to build a mental image of a cup. This co-dependence between sensing and manipulation is at the heart of understanding how humans can so deftly interact with the physical world. Keywords Haptic, Tactile-feedback, Force-feedback, Haptic Interface I. INTRODUCTION Haptic is the newest technology to arrive in the world of computer interface devices. It promises to bring profound changes to the way humans interact with information and communicate ideas. Recent advances in computer interface technology now permit us to touch and manipulate imaginary computer-generated objects in a way that evokes a compelling sense of tactile "realness". With this technology we can now sit down at a computer terminal and touch objects that exist only in the Figure 1.1 : Virtually touching and feeling the object II. WHAT IS HAPTIC TECHNOLOGY Haptic Technology is defined as the technology of virtually touching and feeling the objects and forces. It is a new emerging technology from the area of Virtual Reality that allows computer users to use their sense of touch to feel three-dimensional virtual objects using haptic devices. Touch is a very powerful sense but it has so far been neglected in 388

2 computing. The sensation of touch is the brain s most effective learning mechanism more effective than seeing or hearing which is why the new technology holds so much promise as a teaching tool. With this technology, a person using a haptic device can feel a simulation of a solid object as if it is really in front of him. It is a tactile feedback technology. It means that it gives users the sensation of pressure, temperature, surface texture, weight, shape etc while touching the object with the skin and provides feedback about other physical properties and movements of virtual objects represented by a computer. The word Haptic is originated from the Greek word haptikos, meaning pertaining to the sense of touch and comes from the Greek verb haptesthai, meaning to contact or touch.[3] Therefore, Haptic Technology is defined as the science of applying tactile sensation to human interaction with computers. With this technology we can now sit down at a computer terminal and touch objects that exist only in the "mind" of the computer. By using special input/output devices (joysticks, data gloves, or other devices), users can receive feedback from computer applications. This haptic technology is like exploring the virtual world with a stick. If you push the stick into a virtual balloon, it pushes back. The computer communicates sensations through a haptic interface a stick, scalpel, racket or pen that is connected to force-exerting motors. III. WORKING OF HEPTIC TECHNOLOGY Basically, a haptic system consists of two parts, namely, the human part and the machine part. Both the systems include Sensor(s), processors, and Actuator(s) control circuitry. A sensor is responsible for sensing the haptic information exerted by the user on a certain object and sending it to haptic rendering module. The actuator will read the haptics data sent by the rendering module and transform this information into a form perceivable by human beings. In human system, the human part senses and controls the position of the hand. The nerve receptors perform the sensing, brain performs processing and muscles perform actuation of the motion performed by the hand. While in case of machine system, the machine part exerts forces from the hand to simulate contact with a virtual object. The encoders perform the sensing, computer performs processing and motors perform actuation. Figure 3.1 : Basic Haptic System In case of computer haptic technology, the application programming interface is used to program calls to the actuator into product s operating system. The calls specify which effect in the haptic effect library to play. When the user interacts with the product s touch screen, button or other control, the control position information is send to the operating system, which sends the play command through control circuitry to the actuator and provides sensory feedback that simulates physical properties and forces. The actual process used by the software to perform the calculations of the sense of touch, especially touch, is called Haptic Rendering.[4] It involves sensing the position sensors at the haptic device to obtain the position within the virtual environment. It, thus, consists of detection, response and control algorithms. Capture, Storage and Retrieval of Haptic Data The optimal methods for the description, storage and retrieval of moving sensor data of the type generated by the haptic devices is still the area of search. The techniques captures the hand or finger movement of the user performing the skilled movement and play it back, so that a novice can retrace the user s path, with realistic touch sensation. Captured data include movement in the three- dimensions, orientation and force contact in 389

3 the virtual environment. The techniques for recording and playing back the raw haptic data have been developed for the PHANTOM and CyberGrasp. all sides- front, back, top, bottom- just as if holding it in his/her own hand.[5] IV. HAPTIC INTERFACES AND DEVICES A. Haptic Interface Haptic Interface consists of a haptic device and software-based computer control mechanism. It enables human-machine communication though the sense of touch. By using a haptic interface, a user can not only feed the information to the computer but can also receive information or feedback from the computer in the form of a felt sensation on some parts of the body. B. Haptic Devices Haptic Device is the one that provides a physical interface between the user and the virtual environment by means of a computer. This can be done through an input/output devices that senses the body s movement, such as joystick or data glove. Haptic device is a manipulator with sensors, actuators or both. A variety of haptic devices have been developed for their own purposes. The most popular are tactile based, pen-based, gloves and wearable devices, etc. Some of the major devices are PHANTOM It is a small robot arm with three revolute joints each connected to a computer-controlled electric DC motor. This haptic interfacing device is developed by Sensible Technologies and is the main haptic device used in research. It is primarily used for providing a 3D touch to the virtual objects. This is a very high resolution, six degrees of freedom (DOF) device in which the user holds the end of a motor-controlled, jointed arm. It provides a programmable sense of touch that allows the user to feel the texture and shape of the virtual objects with a very high degree of realism. One of its key features is that it can model free-floaing threedimensional objects. For example, a user of the Phantom could feel an object such as a helmet fom Figure 4.1 : PHANTOM Cyber Grasp CyberGrasp is an innovative force feedback system for the fingers and the hand. It lets us reach into the computer and grasp computer-generated or tele-manipulated objects. It is light weight, forcereflecting exoskeleton that adds resistive force feedback to each finger. The term exoskeleton refers to the hard outer shell that exists on many creatures. In a technical sense, the word refers to a system that covers the user or the user has to wear. Originally developed for the use in telerobotic applications, the CyberGrasp System allows an operator to control a remotely-located robotic hand and literally feel the object being manipulated. Figure 4.2 : CyberGrap Force-feedback Joysticks The first commercial products with some elementary application of Haptic are the Force- Feedback Joysticks that provide the user with the sense of force effects (basically shaking ) while playing, known as force feedback. Logitech and Microsoft have already produced such devices that come in prices proper for home usage and are games-oriented. They enhance the experience of playing video games by applying forces and vibrations on the user s hand, providing feedback from the game-application depending on its kind. For example, by pressing a gun s trigger in a First Person Shooter game, the user feels the vibrations 390

4 coming from the gun s firing. Working with the certain APIs, one can build other than game applications that take advantage of these devices capabilities. V. APPLICATIONS OF HAPTIC TECHNOLOGY Education & Training Haptic tools are used in a variety of educational settings, both to teach concepts and to train students in specific techniques.[6] Haptic educational applications are an under development research field. Haptic devices are employed to teach disciplines such as physics, biology, chemistry, etc. It is helping NASA to explore planets in solar system by controlling the robots.while teaching physics, students are given a virtual environment in which they can manipulate and experience the physical properties of objects and the forces that act on them. Such devices allow students to interact with experiments that demonstrate gravity, friction, momentum and other forces. The users can investigate and explore various 3D objects and feel their material, surface, size, shape, etc. or select, pick-up, hold, move, orient and release/place objects and feel forces on their fingers (weight, torque, collisions, etc). For example, the user can navigate through the solar system, collects information about it and interacts with the various elements that it is consisted of, such as the planets, the satellites, the comets and the asteroids. The user experiences the effect of the gravitational forces when accelerating objects at different distances. For the purpose of interaction the user is endowed with superpowers. The Multi User Virtual Interactive Interface (MUVII) - a H3DI prototype- introduced by HPCLAB, is a chance for the students to experience, feel and steadily learn the effect of simple mechanics in the scale of our solar system. Following figures depicts exploring the planets in order to feel the gravity and the solar system cognition exercise in order to learn the relative positions of the planets with respect to the sun. Figure 5.1 : Exploring the planet Figure 5.2 : Cognitional Exercising Thus, in the educational field, the sense of touch and force-feedback can offer great improvements to the existing teaching methods, and hence enhancing the quality of education procedures. Surgical Simulation and Medical Training Surgery was one of the earliest research topics in computer haptic based training. A computer based teaching tool has been developed using haptic technology to train students. Medical students can use haptic devices to develop a sense of what it feels like to give an epidural injection, perform laparoscopic surgical procedures, use dental or orthopedic drills, or any number of other highly tactile techniques. Such simulators give users the opportunity to develop a tactile sense of the structures, organs, and tissues of the body. The student receives touch feedback from a haptic device while palpating virtual objects. The teacher can visualize the student's actions on a screen and give training and guidance. Such training systems use the Phantom s force display capabilities to let medical trainees experience and learn the subtle and complex physical interactions needed to become skillful in their art. For example, haptic technology helps veterinary students to examine the bovine reproductive tract, simulating rectal palpation. But this virtual surgery is a very complex and challenging undertaking. In machine haptic, surgical tele-robots already helped humans perform cardiac and abdominal surgery. Furthermore, Rutgers Master II is haptic device used in a training simulation for palpation of subsurface liver tumors. Thus, it is easy to imagine the convergence of biosimulation and tele-surgery in the near future. 391

5 Figure 5.3 : Simulation Of Blood Vessels Painting, Sculpting and CAD There have been a few projects in which haptic displays are used as alternative input devices for painting, sculpting, and computer-assisted design (CAD). At CERTEC, the Centre of Rehabilitation Engineering in Lund, Sweden, Sjostrom and his colleagues have created a painting application in which the PHANTOM can be used by the visually impaired; line thickness varies with the user s force on the fingertip thimble and colors are discriminated by their tactual profile. Similarly, in 1999, Donald developed an application in which animations are treated as palpable vector fields that can be edited by manipulation with the PHANTOM. Another role of Haptic technology in CAD can be explained more precisely through the following scenario- When Arthur, a CAD designer, 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 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.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. Cultural Applications Haptic technology is already being used in museums, but on a small scale in very specialized situations. Few museums have yet explored the potential of haptic technology to allow visitors access to three-dimensional museum objects such as sculpture, bronzes, or examples from the decorative arts.[7] One such is the University of Southern California s Interactive Art Museum (digimuse.usc.edu). This museum has begun to look at the use of the PHANTOM device within the museum to allow visitors to feel artefacts. Although it is not yet common place, a few museums are exploring methods for 3D digitization of priceless artifacts and objects from their sculpture and decorative arts collections, making the images available via CD-ROM or in-house kiosks. Haptic technology, thus, raises the prospect of offering museum visitors not only the opportunity to examine and manipulate digitized threedimensional art objects visually, but also to interact remotely, in real time, with museum staff members to engage in joint tactile exploration of the works of art such that someone from the museum's staff can interact with a student in a remote classroom and together they can jointly examine an ancient pot or bronze figure, note its interesting contours and textures, and consider such questions as what is the mark at the base of the pot? Military Training and Simulations Haptic has also been used in aerospace, military training and simulations. Specialized military training can be very expensive involving an element of danger when using real situations, especially for vehicle pilots. There are a number of circumstances in a military context in which haptic can provide a useful substitute information source because there are circumstances in which the modality of touch could convey information that is not available due to certain reasons, not reliably communicated, nor even best apprehended through the modalities of sound and vision. So, haptic technology provides the virtual environments that work well in military applications and military vehicle simulations have probably been the most successful. Possibly the 392

6 most well-known of all the simulators in the military are the flight simulators. The Air Force, Army and Navy all use flight simulators to train pilots. Training missions may include how to fly in battle, how to recover in an emergency, or how to coordinate air support with ground operations. Flight simulators combine visual and auditory elements with haptic technology, including resistance and vibrations in the controls, allowing student pilots to experience the kinds of sensations they will feel when flying real planes. Although flight simulators may vary from one model to another, most of them have a similar basic setup. The simulator sits on top of either an electronic motion base or a hydraulic lift system that reacts to user input and events within the simulation. As the pilot steers the aircraft, the module he sits in twists and tilts, giving the user haptic feedback. Other Applications Mobile Phones Nokia phone designers have perfected a tactile touch screen that makes on-screen buttons behave as if they were real buttons. When a user presses the button, he or she feels movement in and movement out. He also hears an audible click. Nokia engineers accomplished this by placing two small piezoelectric sensor pads under the screen and designing the screen so it could move slightly when pressed. Everything, movement and sound is synchronized perfectly to simulate real button manipulation. Also, Samsung has made a phone, which vibrates, differently for different callers. Motorola too has made haptic phones. Cars For the past two model years, the BMW 7 series has contained the idrive (based on Immersion Corp's technology), which uses a small wheel on the console to give haptic feedback so the driver can control the peripherals like stereo, heating, navigation system etc. through menus on a video screen. The firm introduced haptic technology for the X-by-Wire system and was showcased at the Alps Show 2005 in Tokyo. The system consisted of a "cockpit" with steering, a gearshift lever and pedals that embed haptic technology, and a remote control car. Visitors could control a remote control car by operating the steering, gearshift lever and pedals in the cockpit seeing the screen in front of the cockpit, which is projected via a camera equipped on the remote control car. VI. ADVANTAGES AND DOWNSIDES Advantages 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 take advantage of only one or two sensory channels (sight and sound) to transmit information to people. Haptic promises to open this bottleneck by adding a new channel of communication using the sense of touch. Haptic technology includes sensory feedback. Haptic technology provides a mechanism through which students can actively engage in learning a range of ideas and skills, putting control of learning literally with their hands. Some of the advantages of Haptic Technology are Easy medical training Allow rare, fragile or dangerous objects to be handled Improve access for visually disabled people Allow long distance visitors Increase the number of artefacts on display Time Saving Disadvantages Some of the disadvantages of the haptic technology are Higher Cost Complex in nature Large weight and size Crude experience Requires advance design VII. FUTURE SCOPE The scope for Haptic Technology is increasing manifoldly. The future advancements in haptic technologies is at the forefront of researches. 393

7 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 haptic to complement real experiences. Some of the future advancements of the applications of haptic technology that are at the forefront of the on-going researches are Emotionally Intelligent Computers Affective (emotionally- focused) Haptic is an emerging field. Imagine machines that could read your emotion by the way you touch them. At The University of British Columbia s SPIN Lab (Sensory Perception and Interaction Research Group Lab), researchers are experimenting with new haptic systems designed to both decode and respond to emotionally expressive touch. By making computers smarter about tactile information, SPIN researchers are hoping to also make the computers human.[8] One project getting attention is the Haptic Creature or Cuddlebot, named in New York Times Innovations That Will Change Your Tomorrow, discussed in MIT Technology Review. This haptic creature is a small furry, featureless robot that uses conductive Smart Fur and other sensors to detect touch and react accordingly. It reads nine different touch gestures from the slightest of strokes to scratches. In other research they have learned to mimic the breathing and subtle movements of a live animal. Text for Blind This is another future application of haptic technology. The Design Research Lab in Berlin, Germany has developed a haptic feedback glove designed specifically for blind users to improve texting capabilities. The Lorm glove allows blind users to text by tapping various sensors and to receive text via vibrators. VIII. CONCLUSIONS We conclude that touch plays a huge role in the way we perceive our surroundings and also how we interact with them. Haptic technologies have come a long way in bringing this technology into reality. Haptic Technology is the only solution which provides high range of interaction that cannot be provided by virtual reality. The touch access technology is important till now. But, haptic technology has totally changed this trend. Touch plays a key role when examining objects in the real world but until recently it was not possible to use this realistically in virtual environments and computer based displays. Now haptic technologies are available that lets museums add this missing aspect of lacking realism back into their computer based exhibits. Haptic devices have a lot more to offer museums and are likely to have a big impact. Haptic Technology, thus, make the future world as a sensible one. It enables users to simulate touch and utilize a new input as well as output technology. Large potential for applications in critical fields as well as for leisurely pleasures. Haptic devices must be miniaturized so that they are lighter, simpler and easier to use. And due to the increasing applications of haptic, the cost of the haptic devices will drop down in future. REFERENCES [1] aspx?utm_source=twitterfeed&utm_medium=twitter. [2] [3] [4] [5] [6] [7] [8] 394