Continuing our discussion of robots, let us now take a look at their control centres, namely the computers. There are three parameters to consider for the computational underpinnings of robotic action: the processing power (or speed) of the computer; its memory size; and the price for a given combination of processing power and memory size.
The processing power or computing power can be quantified in terms of ‘million
instructions per second’ or MIPS. And the size of the memory is specified
in megabytes. By and large, the MIPS and the megabytes for a computer cannot be
chosen independently: Barring some special applications, they should have a
certain degree of compatibility (per unit cost), for reasons of optimal
performance in a variety of applications.
An analysis by Hans Moravec (1999) revealed that, for
general-purpose or 'universal computers', the ratio of memory (the
megabytes) to speed (the MIPS) has remained remarkably constant during the
entire history of computers. A ‘time constant’ can be defined here as roughly the
time it takes for a computer to scan its own memory once. One megabyte per MIPS
gives one second as the value of this time constant. This value has remained
amazingly constant as progressively better universal computing machines have
been developed over the decades, as depicted in Moravec's (1999) 'evolution slide':
Machines having too much memory for their speed are too slow (for their
price), even though they can handle large programs. Similarly, lower-memory
higher-speed computers are not able to handle large programs, in spite of being
fast. Therefore, special jobs require special computers (rather than
universal computers), entailing higher costs, as also a departure from the
above universal time constant. For example, IBM’s Deep Blue computer,
developed for competing with the chess legend Garry Kasparov (in 1996-97) had more
speed than memory (~3 million MIPS and ~1000 megabytes, instead of the universally
optimal combination of, say, 1000 MIPS and 1000 megabytes). Similarly, the
MIPS-to-megabytes ratio for running certain aircraft is also skewed in favour
of MIPS.
Examples of the other kind, namely slow machines (less MIPS than
megabytes), include time-lapse security cameras and automatic data libraries.
Moravec estimated in 1999 that the most advanced supercomputersavailable at that time were within a factor of 100 of having the power to mimic the human brain. But then such supercomputers
come at a prohibitive cost. Costs must fall if machine intelligenceis to make much headway. Although this has indeed been happening for a whole
century, what about the future? How long can this go on?The answer is: For quite a while, provided technological breakthroughsor new ideas for exploiting technologies keep coming.
An example of the latter is the use of multicore processors. Multicore chips,
even for PCs, are already in the market. Nvidia introduced a chip, GeForce
8800, capable of a million MIPS speed, and low-cost enough for use in
commonplace applications like displaying high-resolution videos. It has 128
processors (on a single chip) for specific functions including high-resolution
video display. In a multicore processor, two or more processors on a chip
process data in tandem. For example, one core may handle a calculation, a
second one may input data, while a third one sends instructions to an operating
system. Such load-sharing and parallel functioning improves speed and
performance, and reduces energy consumption and heat generation.
Nanotechnology holds further promise for the next-generation solutions to
faster and cheaper computation. DNA computing is an alternative approach being investigated; this technique has the potential for
massive parallelism.
Quantum computing is another exciting possibility.
A factor hindering rapid progress in robotics has been the high costs
incurred on sensors and actuators. Progress in nanotechnology (e.g. the
development of MEMS) is resulting in continuously falling costs of sensors and actuators. It
is now far less expensive to incorporate GPS (Global Positioning System) chips,
video cameras and array microphones, etc., into robots.
Bill Gates announced the development of universally applicable
software packages by his company Microsoft that would further facilitate the
use of ordinary PCs for controlling and developing robots of ever-increasing
sophistication. Many robots already have PC-based controllers. It is
anticipated that a large-scale move of robotics towards universally applicable
PC-based architecture will cut costs and reduce the time needed for developing
new configurations of autonomous robots. In the 1970s the development of Microsoft
BASIC provided a common foundation that made it possible to use software
written for one set of hardware to run on another set. Something similar has
been happening in robotics.
One of the challenging problems
faced in robotics was that of concurrency, namely how to
process simultaneously the large amount of data coming
in from a variety of sensors, and send suitable commands to the actuators of
the robot. The approach adopted till recently was to write a ‘single-threaded’
program that first processes all the input data and then decides on the course
of action, before starting the long loop all over again. This was not a happy
situation because the action taken on the basis of one set of input data may be
too late for safety etc., even though subsequent input data indicates a
drastically different course of action.
To solve this problem, one must write ‘multi-threaded’ programs that can allow data to travel along many paths. This tough problem has been
tackled by Microsoft by developing what is called CCR (‘concurrence and
coordination run-time’). Although CCR was originally meant to exploit the advantages of multicore and multiprocessor systems, it may well be just the right thing needed for robots also. The CCR is basically a sequence of libraryfunctions that can perform specific tasks. It helps in developing multithread applications quickly, for coordinating a number of simultaneous activities of a
robot. Of course, competing approaches already exist, not only to CCR,but also to the so-called ‘decentralized software services’ (DSS) I
mentioned in Part 87.
Although low-cost universal robots will be run by universal computers,
their proliferation will have more profound consequences than those engendered
by low-cost universal computers alone. Computers only manipulate symbols; i.e.
they basically do ‘paperwork’ only, although the end results of such paperwork
can indeed be used for, say, automation. A sophisticated universal robot goes
far beyond mere paperwork. It goes into perception and action in real-life
situations. There is a far greater diversity of situations in the real world
than just paperwork, and in far greater numbers. There would thus be a much
larger number of universal robots in action than universal computers.
This, of course, will happen only when the cost per unit capability falls to
low levels.
It has been questioned why Moravec has never updated his
1999 'evolution slide' I showed in the beginning of this post: 'If the graph's projections were correct and if we
had the software available today, we would be able to purchase a computer to
simulate the human brain in 2010 for $1000'. But this has not happened.
Perhaps Moravec's estimate for the number of MIPS needed to simulate the
human brain was off by a factor between 1000 and 10,000,000. Taking the factor
of 1000 as a better estimate, the modified 'evolution slide' looks as follows:
When will robotic intelligence go past human
intelligence? Perhaps by 2050. Perhaps a little later than that.
Fantastic article! I recently visit and read your content, it is very informative and useful for professional workers. Appreciating for doing the great work.
ReplyDeleteCorporate Training in Chennai
Corporate Training institute in Chennai
Excel Training in Chennai
Social Media Marketing Courses in Chennai
Pega Training in Chennai
Embedded System Course Chennai
Linux Training in Chennai
Primavera Training in Chennai
Corporate Training in Chennai
Corporate Training institute in Chennai
Thank you.
ReplyDelete