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Who Is Magdalene?
Magdalene is a code name for a
robotic hand, which is being developed in our offices at the
moment. The name - it just happened that some of us spelled it
out...and here comes Magdalene
Robots preoccupied men from a
pretty long time ago. Men always dreamt of being replaced at
their working places (mostly because of the hard and exhausting
work). Unfortunately some people used to solve this
problem in different ways trough history like slavery...
Thankfully, there always were bright minds present that wanted
to solve this problem using the fruits of technology. Windmills,
watermills, the mysterious building of the Pyramids,..etc . A
gigantic step forward was made in this century by discovering
the binary machine, popularly called computer. Computers managed
to breathe in life to mechanical constructions. Today the plane
flight is much more comfortable and safer thanks to
the usage of modern computers. Navigation satellites, NU
machines, robots, and all the others moved upwards on the scale
of intelligence. In the first days of their appearance, robots
influenced a great deal of human imagination. Nowadays, robots
have the position they really deserve.
.
Our team decided to assemble a
peaceful robot for chess playing purposes. To be more precise,
it was intended to move the figures on the table. We will try to
write about our adventure in a more popular and simplified way.
Also we will try not to over simplify, so that those who are
familiar with the field of electronics and mechanics, would also
enjoy the texts. (finally, the robot is an electrical and
mechanical unit). I guess it would be acceptable to start with
an introductory terminology about robots, some elementary
theories, divisions, mechanisms, powered systems, sensors,
electronics and in the end something little about software. It
is hard to divide robots into classes. The simple reason is the
criterion. There are lots of criteria. We can divide them into
groups by color, to blue, green, yellow, ...by weight to
pencil-light...but I guess all this looks like fun. One of the
basic categorizations will be by chronological appearance. We
can categorize robots by generations.. Robots of the 0
generation, robots of the 1 generation, Robots of the 2
generation, Robots of the 3 generation...Robots of the 0
generation were those with so called fixed program, they were
not programmable. They did not have the program control unit.
The robot was performing the function it was designed for, until
the end of his working life, simply as a part of a technological
process.
The Robots of the 1 generation,
or programmed robots, they have the option of being controlled
by each degree of freedom (they have an independent power supply
system for each ankle). After being programmed, robots perform
one same program (path, task...)
The Robots of the 2 generation,
called adoptive robots, have a possibility of flexible change of
their program of moving, in accordance with the real situation.
All this thankful to the microprocessor systems implanted.
They receive information from input devices, process the
information, and generate a signal of adaptive controlling.
Robots of the 3 generation,
intelligent robotic systems. They are on the limits of
artificial intelligence. Some further categorizing should be
commanded robots, copying robots, half-automatic robots,
supervisable robots, dialogable robots (a class of remote
controlled robots) then egsoscheletical and others... (each of
these items will be explained later). In comparison with
computer technology, where each new generation replaces the
previous, in robotic industry, all the generations are present
at the same time and each of them has a specific application.
Robots of the 0 generation are
present in a large number nowadays. They are used in some more
simple jobs. We come to a logical question:
Why these Robots of 0 generation
are still present, when robots of newer generation are capable
of performing much delicate tasks? They answer is the price.
Imagine the next situation - we
have a doctor of science, but we use him for digging channels.
The robot mechanisms can be of different structure and also of
different level of quality. We have to take care of a compromise
between price and performances when building a robot. We decided
to build a manipulating robot with 4 degrees of freedom. (q1 q2
q3 q4)
q1-rotation of the complete robot
round the vertical axis
q2-rotation of part 2 round the
base
q3-rotation of part 3 round part
2
q4-opening and closing the hand
The Robotic mechanism on the
picture is already assembled and tested-actually-IT WORKS-. The
Robot belongs to the group of RRR mechanisms. It has a pretty
large manipulating path, thanks to the rotating connections. Its
skeleton is pretty simple. All the 3 powering motors are in the
base of the construction, and they don't produce an additional
effort (weight), that is most of the time quite important. Step
motors are not as strong in comparison to servo motors used for
robotic mechanism. In case you ask why we were not using servo
motors, the answer is once again...THE PRICE!
author: Spasoje Savić, dipl.eng
translated by: Simeon
Todoran
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