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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.
Program returns adc_pp value and exit continue main loop.4. that case program exit. increase adc_pp_aver
variable actual adc_pp value.
Illustration 4. 32th calculation, value shifted down and
adc_pp_aver value printed screen with correspondent axis comment. was created for development version of
anemometer let know little about amplitude affection for computation wind
speed. One them adc_ppx_aver or
adc_ppy_aver variable loaded with its counting index.
Program continue inside one two flag conditions. flag not wind calculation state,
sequence too weak measured time too low.
At first local variables are loaded.lower than min update them. When shadowed little bit space between sensors, could see amplitude
value goes down and airspeed goes negative values because delayed response of
comparator. adc_pp is
lower than 800, received signal too weak include measured time calculation. Then we
29
. Most of
measurements have adc_pp higher than 900, therefore permit choose measured
time from better signal quality. Then program test from which axis has
measured sequence know where store results.12: Flowchart ADC peak peak function
4.
When loop done, program calculate ADC peak peak value. Its results
aren’t use for wind wind calculation.10 ADC average function
This function serve only inform about amplitude receiving signal. So
program set flag for another measurement and wind calculation will skipped
