|
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.
flag not wind calculation state,
sequence too weak measured time too low. So
program set flag for another measurement and wind calculation will skipped.
When loop done, program calculate ADC peak peak value.4.10 ADC average function
This function serve only inform about amplitude receiving signal. When shadowed little bit space between sensors, could see amplitude
value goes down and airspeed goes negative values because delayed response of
comparator. Its results
aren’t use for wind wind calculation. adc_pp is
lower than 800, received signal too weak include measured time calculation.
Program continue inside one two flag conditions.lower than min update them. that case program exit.
Illustration 4. Then we
29
. 32th calculation, value shifted down and
adc_pp_aver value printed screen with correspondent axis comment. Then program test from which axis has
measured sequence know where store results.
Program returns adc_pp value and exit continue main loop.
At first local variables are loaded. was created for development version of
anemometer let know little about amplitude affection for computation wind
speed. Most of
measurements have adc_pp higher than 900, therefore permit choose measured
time from better signal quality. One them adc_ppx_aver or
adc_ppy_aver variable loaded with its counting index.12: Flowchart ADC peak peak function
4. increase adc_pp_aver
variable actual adc_pp value
