18-01-2013, 10:34 AM
HAPTICS TECHNOLOGY
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INTRODUCTION
Creating robots that can see, feel, smell and taste
It has taken millions of years of evolution to create the myriad of animal designs that roam the Earth today. But despite the incredible range of shapes and sizes that have resulted, many of these creatures share some very basic and vital senses vision, touch, smell and taste.
So fundamental to survival are these senses, that roboticits overlooked the sheer complexity of their physiology, until now and finally after years of painstaking
Research, we are beginning to create robots that can interact with the world around them and the result is almost life-like.
Sight
Feel
Smell
Taste
The standard list of five senses does not really give our bodies credit for all of the amazing things they can do. There are at least a dozen different things we can sense.
In order for us to have a sense, there needs to be a sensor. Each sensor is turned to one specific sensation. For example, there are sensors in your eyes that can detect light. That is all that they can detect. To track down all of the different senses a person has, the easiest things to do is to catalog all of the different sensors. Here is a reasonable list.
The fight for sight
Artificial vision involves far more than simply attaching a camera to the head of a robot. If robots are to actually react in a suitable way, they must be able to interpret what they are seeing.
How do you get a robot to recognize an apple? You have to program it with enough information in its internal memory system, so that the apple could not possibly be anything else. But look around you; think how much information you would have to provide to account for all the objects in the room, let alone the world!
In the broad picture, artificial vision is still in its infancy. There are no HAL 90000s just around the corner, but when that day arrives, the robotics industry will take off like never before.
To feel for real
AS you touch your keyboard now, millions of tiny nerves relay information to the brain about the position, texture and movement of the keys. Robots have no impulses, so how do they manipulate screwdrivers and spanners to perform delicate tasks?
The story of artificial touch begins in an area of virtual reality called HAPTICS which describes the physical handling of virtual objects. With your fingers placed in special thimbles, you can pluck non-existent objects of a virtual environment and even watch your virtual hands doing it!
Manayan Srinivasan, director of the popular Touch Lab, explains. “We could create a doughnut shape ….. make it feel sticky on the outside, with a gooey virtual jelly centre”
One of the most exciting applications of Haptics is telerobotic surgery. Surgeons can perform an operation without actually being present. Using virtual technology, they not only control the robot from afar, but also can actually feel their way through the operation.
In Austalia, Professor Andy Russell of Monash University is creating robots that can sense temperatures changes through touch. By placing a heater in the robot finger to mimic the heating of blood in our fingers and a thermistor to sense the temperature change, he has created robots that can follow heat trails.
Robots that smell!
Like ants following there own pheromone trails back home, robots can be fitted with special quartz crystal microbalance (QCM) sensors to detect and follow specific chemicals along the ground. Again Professor Russell explains, “The QCM sensors actually weigh the odor molecules and the extra weigh reduces the crystal frequency”
With the ability to sense particular odors in this way, the applications of robots will stretch yet further. For example, swarms of robots could move together without colliding by avoiding the smell of their neighbors.
Just a taster!
In January this year, a hand-held robotic tongue was unveiled to the world. Now threatening to replace professional tasters, this tongue is able to distinguish not only between two different wines from the same winery but also between different years! Sophisticated wine connoisseur it may be, but the science behind it is simple The tongue’s electric circuit contains four chemical sensors relating to the four basic tastes sweet, sour, salty and bitter. These sensors absorb dissolved substances differently. Specific foods have a unique “fingerprint” of these substances, therefore affecting the conductivity of the circuit in their own unique way.
ABOUT HAPTICS LABORATORY
The Haptics Laboratory works on the engineering and design of design of haptic interfaces, that is, of systems, which comprise software and hardware components that concern the sense of touch.
They work on on-line computational models of interaction between objects (deformation, friction, cutting, etc) which can provide high-fidelity simulations as needed, for example, in the construction of surgical simulators. They are also interested in construction of surgical simulators. They are also interested in the study of perpetual effects involving touch, and to take advantage of them to create devices, visualization methods and tactile displays.
The laboratory is involved in exciting applications including rehabilitation, operator assistance in space, medicine, and computer music performance. In the past ten years, a Varity of haptics devices were created, including the Pantograph and the Freedom-7.Other devices based on different principles are presently being developed Actuators and their methods of control, being at the source of movement, are also of great interest.
HUMAN FACTORS IN HAPTICS INTERFACES.
Haptics is the study of how to couple the human sense of touch with a computer-generated world. One problem with current virtual reality systems is the lack of stimulus for the sense of touch. For example, if a user tries to grab a virtual cup there is not a non-visual way to let the user know that cup is in contact with the user’s virtual hand. Also there is not a mechanism to keep the virtual hand from passing through the cup. Haptics research attempts to solve these problems and can be subdivided into two sub fields, namely:
• Force feedback
• Tactile feedback
Force feedback is the area of haptics that deals with devices that interact with the muscles and tendons that give the humans a sensation of a force being applied. These devices mainly consist of robotic manipulators that push against a user with the forces that correspond to the environment that the virtual effector is in.
Tactile feedback deals with the devices that interact with the nerve endings in the skin, which indicate heat, pressure, and texture .These devices typically have been used to indicate whether or not the user is in contact with a virtual object. Other tactile feedback devices have been used to stimulate the texture of a virtual object.