Virtual Reality, Interaction and Haptics
Any interaction between a human and a machine is feedback – even putting the cursor on the screen in the right place by moving a mouse is a feedback process. Perhaps the human-computer interaction is Virtual Reality.
Here the computer generates an artificial world which it communicates with the human. What it looks like is common, and can be done using 3D goggles or a CAVE – which is a room where the world is projected on its walls. Adding sounds is also easy. Being able to smell the world can be done. But it is also interesting to be able to feel the world.
If the human moves his head, for instance, then he is looking somewhere else in the world, and so the computer needs to know about the movement, and send a revised version of the world to the human – a different view – the sounds may be from a different place, etc. So this is very much a feedback process.
Related to this is augmented reality, when the computer conveys images of a ‘real world’, on to which extra information is added. Head up displays for pilots in cockpits are an example. We will see next week images of a robot moving around onto which test is projected showing its ‘emotions’.
This can be used for remote control or tele-operation. Robots are sometimes sent into an environment unsafe for humans to do a task. But rather than preprogramming the robot for the task, a human can be provided with an image of what the robot ‘sees’ and use that image to command the robot to operate in a particular way.
It can also be used in robot-assisted surgery.
In some of these later applications, it is not only important for the human to see what is happening but also to feel it. One of the specialties at Reading is Haptics - which is about touch.
Here you might want to be able to feel different surfaces – are they smooth, or rough?
If you are trying to get a robot to move something, you may need to know how much force to apply, so you need to get so called force feedback.
When we pick up an egg for instance, we need to grip it sufficiently strongly that it does not fall from our fingers, but if we press too strongly it breaks. In fact our finger tips have sensitive sensors and without knowing it we press sufficiently hard that the egg does not quite slip. This is a feedback process.
Haptic devices are ones which generate information to you about what a (potentially imaginary) object feels like, or how the object reacts when you push at it. Often these devices look a bit like a robot arm – and you hold the device and it moves subtly giving your finger tips the sensation of feeling a surface say. Or the device pushes back at you, so you can feel force.
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