Robots
When I was young, Robots were one of the things which used to mesmerize and compel
me to think about them. I used to dream about them, talking and playing with
them, giving orders to do my home work. I always wanted to make my own Robot so
that I can make him do whatever I used to saw in dreams. That time I was not
aware that to make a single robot, hundreds of hardware components are
programmed by thousands of codes in which millions of instructions are hidden.
To make a robot we require hardware components, robotic software and programming
knowledge about them.
- Batteries
- Actuators
- Motors & servos
- Sensors
- Microcontrollers
- Structure material
Batteries:
For making our robot work, we need a power supply. As a source of power we
use batteries. A battery is one or more electrochemical cells which convert
stored chemical energy into electrical energy. There are two types of batteries:
Primary batteries, these are disposable batteries designed to be used once.
Another type is secondary batteries which are rechargeable batteries; they can
be used number of times. We can find batteries in different sizes as well. We
can get as much power as we want for our robot. This is done by placing
batteries in parallel. Placing batteries in parallel will give us certain amount
of current we need. But we must be very careful while we do this because wiring
batteries in parallel can cause inefficiency and sometimes damage. We can use
Lithium-ion batteries, most advanced form to get portable power plus we can
recharge Li-ion batteries whenever we want to. However Nickel-cadmium batteries
are perfect for small sized robots, we can get highest power from these types of
batteries, another advice while connecting batteries in parallel is never
connect an old battery with a new one as their rate of charging and discharging
is always different.
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Battery
Actuators: An Actuator is a kind of motor for moving and controlling a system. It
needs a source of energy to operate. It can be in the form of electric current,
pneumatic and hydraulic fluid pressure. It is based on the principle of
converting any form of energy into motion, what they do; they transform an input
signal into motion given to them. Actuators create motion insider robots. In
language of robotics, actuators are the muscles of robots. Most popular
actuators are electrical motors. Linear actuators are used in industrial robots
to provide them forward and backward motion.
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Actuator
Motors and Servos:
We generally use brushed and brush less DC motors in Robot. However, AC motors are
also in use but they are popular for industrial robots. Electrical motors
convert electrical energy into mechanical energy. DC motors are very commonly
used in small sized robots. It is nothing but an electric motor which runs on
direct current electricity.
DC-motors are very easy to use. Servos are also used with motors. A servo is
actually an automatic device that is used to correct the performance of the
system
Servos are used in robotics for different uses: e.g. to move a sensor around, or
to move the legs of a robot. A servo can be modified to use as a DC motor. The
Good thing with DC motor is that it is non-polarized so we can reverse
the direction of voltage. Voltage is an important parameter to consider
as torque depends on voltage, the more voltage we provide, the more torque it
will produce. But we have to do it wisely as less voltage will lead to very less
torque whereas large amount of voltage can cause overheating which may lead to
damages. If you apply too much, it will overheat and the coils will melt.
Sensors: A Sensor is a kind of a device which is used to transfer physical phenomena into
electrical signals. We used sensors to take internal feedback and external
interaction with the environment as well. A sensor must have accuracy,
Preciseness and must satisfy operating range. There are a wide variety of
sensors we use: Metal detectors, UV detectors,
Gyro, resistive bend sensors, IR sensors are used when we design a simple
moving Robot or a robot which is made to detect obstacles, Sensors are mainly
used for detecting purposes like motion detection, obstacle detection even we
have sensors for color detection as well.
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color sensor
Micro-controllers:
Micro-controllers are nothing but small computers on a single IC which have programmable I/O peripherals, memory and Processor cores. In our day to day
life the things we use microcontrollers are found in almost every small machine
or device we use. From washing machine to microwave oven these small smart
computers can be found in each and every automatic machine nowadays. They are
very commonly used as they are economical, small in size and require almost zero
power plus can be found in large varieties. Thus, very commonly used in making
different types of robots.
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Micro-controller
In short, a micro-controller is nothing but a black chip
with pins. This black chip when contains some additional components like
capacitors timers etc. we called it as an augmented micro-controller or simply micro controller. In augmented micro-controller we don't have to do assembling as
they already have inbuilt features. The most important part of any micro-controller is its I/O ports. The input port is used to take input data from
the sensor and then according to this data output signals are sent by output
ports to external parts like motor or servo. The I/O port is of two types:
Analog Input Ports and digital I/O ports.
Analog input ports are used to connect sensors to our robot. It is also known as
analog to digital convert. They convert analog signal into digital signal
sensors.
Sensors take data in which is in analog form. Actually we record voltage which
is in number.
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Digital I/O
Ports: Digital ports are just like analog ports;
they are rarely used in sensors. They are used in on/off switches. They are used to control motor speed plus they
are used in LED. This is done by sending 5v for on and 0v to show off. There is
an interesting fact which I have faced when I have designed one of robots. I
wanted my Led to glow as half of its brightness as it normally does, now let me
tell you how it can be done... Use a SQUARE WAVE, except this you can also make
your motor speed half of its original speed by using the same wave. Actually
square waves are like turning something on and off so fast that it is like as if
you are sending an analog signal to do the same function.
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PWM wave
Electronics:
Electronics contribute a lot (no doubt) in the designing of robots. Materials like
Capacitors, Resistors, LEDs, Voltage-regulators, rectifiers, crystal
oscillators, transformer and transistors Potentiometers, diodes relays
etc. are used in its designing.
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Structure
materials:
As in constructing any building where cement and concrete materials are required, we
also require some materials to give our robot a structural form. Base is the
first thing in its structure. we can use wood. We can try Balsa wood. It is very
light in weight. Carbon fiber can also be another good option as it is also very
light in weight and proves strong. But its strength to weight ratio is high.
HDPE. A light weight plastic can also be used as it is economical compared to
aluminum. We also need tape, glue and epoxies in its designing. Now all you need
is to use appropriate algorithm suitable according to your type of robot and
design a new robot by using these hardware components.
Conclusion
Designing a robot is not a big deal. but we should have a very clear idea about
what we want to design and complete knowledge about the materials we have to use
to design our dream robot. Any type of confusion regarding any hardware material
should not be avoided as little knowledge about anything can be dangerous. It's
better to collect all the information about the component (involving all its
benefits and harm it can cause) you want to use in building your robot. One more
thing which is really very important the activities should be safe and should
not create any harm to you as well as surroundings. Hope it would be helpful.
SO
GOOD LUCK!!!!