ULTRAZVOČNI MERILNIK RAZDALJE Z UPORABO DVOJIŠKE FREKVENČNE SKOČNE MODULACIJE

HOČEVAR, JOŽE (author), Možek, Matej (mentor)

V magisterskem delu je predstavljena izdelava ultrazvočnega merilnika razdalje z visoko natančnostjo meritve z uporabo binarnih frekvenčnih skokov (binary frequency shift-keyed , BFSK ). V delu je predstavljen učinkovit algoritem, ki kombinira tako funkcijo časa leta ( time of flight, TOF ), kot tudi fazni premik. Omenjena metoda merjenja omogoča večji razpon meritev, kot jih omogoča samo meritve z primerjavo faze, pri temu pa je natančnejša kot je meritev z merjenjem časa leta ( TOF ). Z FPGA (Field-programmable gate array ) vezjem smo generirali BFSK generator in detektor faze, ki nam je omogočil posnetje signalov in izračun časa leta, dveh frekvenčnih razlik in predstavitev rezultata meritve na LCD zaslonu. Poizkusi so bili opravljeni v zraku z uporabo BFSK z frekvencama 39kHz in 41kHz. Željena je bila bila natančnost meritve ± 0,05mm pri razdalji več kot 6000mm, vendar zaradi visoke cene kvalitetnih ultrazvočnih oddajnikov le te nismo uspeli doseči. Glavna prednost ultrazvočnega merilnika razdalje je visoka natančnost, nizka cena in enostavna implementacija v obstoječe sisteme.

• Language: Slovenian
• Keywords: ultrazvočni merilnik razdalj, primerjava faze prejetega in oddanega signala, merjenje razdalje z FPGA, detekcija faze
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2016
• PID: 20.500.12556/RUL-84062
• Publication date in RUL: 07.07.2016

Secondary language

• Language: English

Abstract

This masters degree thesis presents development of ultrasonic distance measurement equipment with high accuracy using binary frequency shift-keyed ( BFSK In this thesis is demonstrated efficient algorithm, that combines time of flight with phase detection. With this method we could manage to measure larger distance as measurement with only phase detection and it also enables us more accurate measurement of distance as time of flight method. With FPGA circuit we generated BFSK generator and phase detector, that enables us recording signal and calculation of time of flight, two phase differences and displaying measured result on LCD display. Test's were performed in air, with usage of BFSK modulation with frequency's 39 kHz and 41 kHz. Desired accuracy range of measurement was 0,05mm at distance over 6000mm, but because of high price range of high quality transducers, we did not manage to achieve this goal. Anyway main advantage of ultrasonic distance measurement is high accuracy, low price and easy implementation in existing system.

• Keywords: Ultrasonic distance measurement, phase comparation of transmitted and received signal, distance measurement using FPGA, phase detection