Delovanje detektorjev kovin

diplomsko delo

Jaka Škrlep (Author), Tadej Tuma (Mentor)

Abstract

Detektorji kovin so naprave, ki so sposobne zaznati kovinske predmete v okolici iskalne sonde. Nekateri lahko celo na grobo določijo, za katero kovino gre. Diplomska naloga je razdeljena na tri dele; teoretični opis delovanja detektorja, sledita mu opisa strojne opreme in programa, ki kontrolira njegovo delovanje. V prvem delu je predstavljena zgodovina detektorjev kovin, kako delujejo in kakšne vrste tehnologij detektorjev poznamo. Prav tako so opisane osnovne lastnosti, kot so frekvenca, oblika navitij, velikost navitij, ki se navadno uporabljajo v praksi. Prikazana je tudi izdelava navitij. V drugem delu se spustimo v načrtovanje in izdelavo vezja. Predstavljen je Wien – mostičev oscilator, kateri nam generira signal določene frekvence. Generiran signal nato peljemo v oddajno tuljavo. Signal, ki ga zazna sprejemna tuljava, nato peljemo na vezje za detekcijo amplitude in na vezje za detekcijo faznega zamika. Na podlagi teh dveh vrednosti lahko ugotovimo prisotnost kovine v magnetnem polju. Zaradi različnih magnetnih in prevodnih lastnosti kovin lahko te tudi na grobo ločimo med seboj. V programskem delu je predstavljeno delovanje mikrokontrolerja. Uporabljeno je razvojno vezje STM32 Nucleo F446-RE. Na njem izkoristimo analogno-digitalni pretvornik za obdelavo signala, ki ga dobimo iz analognih vezij za detekcijo amplitude in faznega zamika. S pomočjo mikrokontrolerja generiramo tudi nizkofrekvenčni signal, ki je ob prisotnosti kovine povezan na brenčač. Uporabljena je tudi tipka za izbiro načina delovanja in tipka za spreminjanje referenčnih vrednosti.

Keywords

detektorji kovin;oscilatorji;magnetizem;ločevanje kovin;visokošolski strokovni študij;Aplikativna elektrotehnika;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FE - Faculty of Electrical Engineering
Publisher:	[J. Škrlep]
UDC:	621.318.381(043.2)
COBISS:	79816707
Views:	272
Downloads:	52
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	ǂThe ǂprincipal of metal detectors
Secondary abstract:	A metal detector is a device that is capable of detecting metal objects near its search head. Some more advanced are even able to discriminate between metal types. This Diploma is constructed out of three parts. In the first part, the theoretical background of metal detectors is introduced. It is followed by a Hardware and software part. In the first, I described a short history of metal detectors, how they work and what kind of metal detecting technologies are used today. Basic properties like coil types, coil sizes, and operating frequency are also mentioned in the first section. In the second section, we dive into the designing and production of the circuit. For signal generation, the Wien-Bridge oscillator is used. It generates a stable sinusoidal signal of pre-calculated frequency. The generated signal is connected to the transmitter coil. The signal that is picked up by the receiver coil is then connected to amplitude and phase detection circuits, which help us transform signal changes into a more digital-friendly signal. These two values are important for metal discrimination. Transformed signals are then connected to the analog pins of the microcontroller. The operation of the microcontroller is described in the software part. AD converter is used for the conversion of phase shift and amplitude change signals. The microcontroller is also used for PWM signal generation, which is connected to the Buzzer. If there is a metal object near the search head of the metal detector, the buzzer will produce a sound. There are also two buttons. The first one is used for mode selection, and with the second one, we can set the reference values.
Secondary keywords:	metal detector;oscillator;magnetism;coil;metal discrimination;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000315
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za elektrotehniko
Pages:	29 str.
ID:	13668076