|
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.
Its results
aren’t use for wind wind calculation. increase adc_pp_aver
variable actual adc_pp value. So
program set flag for another measurement and wind calculation will skipped.10 ADC average function
This function serve only inform about amplitude receiving signal. One them adc_ppx_aver or
adc_ppy_aver variable loaded with its counting index. adc_pp is
lower than 800, received signal too weak include measured time calculation. When shadowed little bit space between sensors, could see amplitude
value goes down and airspeed goes negative values because delayed response of
comparator. 32th calculation, value shifted down and
adc_pp_aver value printed screen with correspondent axis comment.4.
Illustration 4.12: Flowchart ADC peak peak function
4.
At first local variables are loaded. flag not wind calculation state,
sequence too weak measured time too low.
Program continue inside one two flag conditions. was created for development version of
anemometer let know little about amplitude affection for computation wind
speed. that case program exit.
Program returns adc_pp value and exit continue main loop. Then we
29
.lower than min update them.
When loop done, program calculate ADC peak peak value. Then program test from which axis has
measured sequence know where store results. Most of
measurements have adc_pp higher than 900, therefore permit choose measured
time from better signal quality
