|
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.
We’ve implemented all circuits one layer printed circuit board suitable connect
as module evaluation board. All created code anemometer file
and separated into few functions.
We were receiving signal from distance. Sensors has been put wooden holders, which
keep them rectangular angle between axis. Comparator gives rising edge with higher value than top reference lower
value than bottom reference.1 Hardware
We’ve built analog bandpass filter adjust PWM signal. Hardware part with its circuits,
components, simulations and module board creation and digital part with its code and
its documentation.
34
. enable PWM and Timer and wait for digital input
interruption, let react received signal soon possible.2 Software
Software was the main part the development. Both was moved functional version laboratory conditions.
There hasn’t been done any measurements outer conditions with various weather
conditions. But can estimate preciseness about +/- m/s for both and value of
wind speed. From ultrasonic receiver we’ve
obtained 200 peak peak signal.
5. Amplification has been set used all
range converter. this amplifier we’ve connected ultrasonic transmitter.
Written code well documented suitable for further development and
improvements. Then construct amplifier reach V
peak peak its output. We’ve added component and used rail rail
operational amplifier amplify input signal. Program use peripherals from microcontroller to
control created hardware. It
use signal strength correction well temperature correction adjust airspeed
constant. favor that we’ve
obtained kHz harmonic sinus signal.RESULTS
There are two parts, which were developing. In
practice refers about For calculation last 256 measured time delays used.
Program calculate new value axis with every 32th measurement.
Furthermore we’ve used external comparator with amplified received signal its
inputs.
5
