Thames & Kosmos SUPERSPHERE, Руководство по эксперименту

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6
Submarine
BACKGROUND TECHNICAL INFO
ABOUT SOUND
Sound is a form of energy that moves as a pressure wave
through substances (gases, liquids, and solids). Typically,
humans can hear and feel many sounds. Sounds are
caused by
vibrations, which are back-and-forth
movements of particles. Humans can sense sound when
these vibrating particles make contact with their
eardrums, which send signals to their brains.
Many sounds vibrate at a frequency that the normal
human ear can detect. Frequency is simply the number of
waves in a given period of time. Typically, humans can
hear sound waves in the frequency range of 20 hertz
(which means cycles per second) to 20,000 hertz (20
kilohertz).
ABOUT THE SOUND SENSOR
Sound sensors work somewhat like a human ear. A sound
sensor has a thin flexible membrane inside it called a
diaphragm. The diaphragm vibrates when sound waves
hit it. This vibrating motion of the diaphragm is converted
into electrical signals, which are sent to a microprocessor
for processing. A sound sensor is like a simple
microphone.
The sound sensor in this kit is designed to sense the
intensity of sound. The intensity of sound relates directly
to loudness, and is a measure of the amount of energy in
the sound wave. The programming app used with the
robots in this kit receives the signals from the sound
sensor and recognizes and counts brief sounds that are
much louder than the ambient sound. The sound of your
hands clapping once is a perfect example of a loud sound
detected by this app. In other words, the app listens for
the number of loud sounds — like claps — that the sound
sensor senses. The app allows you to program different
sequences of commands to run, depending on the number
of claps the sound sensor detects. With this, you can
program your robots to perform different actions
depending on how many claps (one to four) it detects.
ABOUT THE SUPER SPHERE’S MOVEMENT
The primary robot model in this kit, the Super Sphere,
moves in a very unique and interesting way. The Super
Sphere has
two motors (called motor A and motor B)
mounted inside of it on a mechanical structure. The
motors are connected to the
Bluetooth battery box, which
turns them on and off based on instructions coming from
the app. Motor A is mounted horizontally and connects to
a gear that is directly connected to the inside of the
spherical shell. When motor A turns, it causes the sphere
to roll forward or backward because there is a heavy
weight keeping the inner mechanical structure upright
while the lighter sphere spins around it. This is much like
how a hamster running on the inside of a hamster wheel
always stays at the bottom of the wheel because of its
weight.
Motor B is mounted vertically inside the sphere. When it
turns, it spins the weights which are hanging down from
the inner mechanical structure. Due to a complex physics
concept called angular momentum, when the heavy
weights spin clockwise, the outer sphere actually rotates
counterclockwise. Likewise, when the weights spin
counterclockwise, the outer sphere rotates clockwise.
Again, this is related to why the hamster spinning on the
wheel always stays at the bottom, except the spinning
motion is happening in a different plane. It is also related
to how a toy top spins. Combining these two motions at
the same time allows the robot to move forward or
backward and turn to the left or right at the same time.
But don’t just take our word for it — build it and see for
yourself how it works!
Illustration of a sound wave
Particles
Wave
Compression
Refraction
The sound sensor
detects the
number of claps.
The app runs
different parts of the
program depending
on how many claps
it detects.
motor A motor B motor A motor B motor A motor B