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Kategorie: Diplomové, bakalářské práce |
Tento dokument chci!
Práce popisuje principy a problémy při realizaci ultrazvukového anemometru. Je popsán princip výpočtu rychlosti větru a následné korekce výpočtu. Pro realizaci jsou využity ultrazvukové sensory a microcontrolér ARM Cortex-M3. Práce se zabývá generováním PWM signálu, jeho analogovou filtrací, zesílením a odvysíláním. Na přijímací straně jeto nízkonapěťový zesilovač a komparátor. Vyvíjený kód je popsán pomocí vývojového diagramu.
1. can expect time delay non windy conditions based this
equation:
(2. this case can suppose that the wind
speed the equation (2. The wind affects the sound wave making going slower faster. [1]
1.2)
There another weak dependence air humidity.THEORETICAL BACKGROUND
How was said, the calculation wind speed proceed knowledge time delay
between sensors.2 Time delay windy conditions and wind speed
A sound wave affected the movement the transmission medium, air the
wind.2).4) negative. case less time
delay obvious that airspeed increased speed wind.1 Correction speed
Airspeed dependent mainly temperature.3)
where a[g/m3
] amount water the air. The correction based on
knowledge amount H2O grams per cubic meter.1)
where d[m] distance and c[m/s] airspeed. When vector wind
speed same oriented like direction sound propagation, obtain the equation [1]:
(2. With air temperature 20°C the
measured temperature with 100% relative dampness about higher. The increase water molecule in
the air cause increase airspeed.1) have add variable which represent speed wind v[m/s]. Then have correct our measured temperature
and use the corrected temperature calculation above (2. Distance between sensors a
constant, but airspeed should corrected concrete atmospheric conditions [1]. can adjust this equation just calculate
2
. [1]
(2. equation
(2.4)
When the vector wind speed has opposite direction than propagation the
sound, there will increase time delay. know the air temperature T[°C]
between sensors, can correct airspeed according following equation [1]:
(2
