Iskanje po katalogu digitalne knjižnice

Opis: V magistrskem delu je predstavljeno načrtovanje trajektorije 3D mehanizma, namenjenega testiranju malih UWB radarskih sistemov. Opisana sta zasnova sistema in načrtovanje ravninske in krožne trajektorije v 2D ravnini. Sledi opis vključitve tretje prostostne stopnje, ki poskrbi za želeno orientacijo v posamezni točki 2D ravnine. Tako smo dosegli, da je bilo mogoče testno napravo na mehanizmu ves čas orientirati v želeno smer skozi celotno trajektorijo. Izdelan in predstavljen je tudi uporabniški vmesnik, namenjen vodenju sistema. Na koncu je predstavljeno še testiranje delovanja celotnega sistema.
Ključne besede: pozicionirni sistem, koračni motor, načrtovanje trajektorije, uporabniški vmesnik
Objavljeno v DKUM: 15.10.2025; Ogledov: 0; Prenosov: 13
Celotno besedilo (2,87 MB)

Opis: V magistrskem delu je bila predstavljena metoda za zaznavanje brezpilotnih letalnikov, ki združuje optično kamero in radar. V optičnem podsistemu so bili objekti zaznavani z uporabo algoritma YOLOv8, implementiranega na energijsko učinkoviti platformi NVIDIA Jetson Orin Nano, ki omogoča obdelavo v realnem času. Radarski podsistem temelji na FMCW radarju, ki izkorišča Dopplerjev pojav pri frekvenci 10 GHz in pasovni širini 500 MHz, kar omogoča natančno merjenje razdalje in hitrosti. Eksperimentalni rezultati so pokazali, da združevanje optičnih in radarskih podatkov poveča robustnost in zanesljivost zaznavanja brezpilotnih letalnikov v različnih okolijskih pogojih.
Ključne besede: dron, detekcija dronov, radar, Dopplerjev radar, YOLOv8
Objavljeno v DKUM: 04.09.2025; Ogledov: 0; Prenosov: 43
Celotno besedilo (4,09 MB)

Opis: The paper describes an event-triggered nonlinear feedback controller design. Event triggering is a real-time controller implementation technique which reduces embedded system utilization and relaxes task scheduling of the real-time system. In contrast to classic time implementation techniques, the event-triggered execution is validated regarding the introduced triggering policy. The triggering rule is a boundary, where the last task value is preserved until the rule is violated. In the given paper, two different event-triggered strategies are designed for the class of dynamic systems with integral behavior. Both methods are based on sliding mode controller design, where the triggering rule of the first design involves only a partial state vector, which is a direct consequence of the triggering rule derivation throughout the Lyapunov stability analysis. In the second approach, the sliding mode controller is designed upon prior stabilized systems with the additional term, which enables derivation of the triggering rule based on the whole state vector. The second approach offers better closed-loop performance and higher relaxation of the system utilization. The selection of triggering boundary is related closely to the derived minimal inter-event time, which impacts the computational burden of the real-time system and closed-loop performance directly. The derived controllers are compared with the classic sample and hold implementation techniques. The real-time results are presented, and system performances are confirmed regarding embedded system task relaxation, lowering the computational intensity and preserving closed-loop dynamics.
Ključne besede: sliding mode control, event-triggered control, lowering computational intensity, task relaxation
Objavljeno v DKUM: 28.03.2025; Ogledov: 0; Prenosov: 14
Celotno besedilo (18,67 MB)
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Opis: V diplomskem delu je predstavljena predelava komercialne kosilnice v avtonomno vozilo. Predelavo je bila izvedena s pomočjo mikroračunalnika ter RTK GPS modula, ki omogoča natančno določanje lokacije vozila v realnem času. Avtonomna vožnja se izvaja s pomočjo ROS okolja, ki skrbi za korektno delovanje vseh komponent. V delu željeni cilji glede natančnosti niso bili doseženi, vendar je rezultat kljub temu zadovoljiv.
Ključne besede: GPS, RTK, ROS okolje, OpenMower, Raspberry Pi4
Objavljeno v DKUM: 19.09.2024; Ogledov: 0; Prenosov: 60
Celotno besedilo (4,41 MB)

Opis: This paper presents the design of a high-voltage pulse-based radar and a supervised data processing method for soil moisture estimation. The goal of this research was to design a pulse-based radar to detect changes in soil moisture using a cross-hole approach. The pulse-based radar with three transmitting antennas was placed into a 12 m deep hole, and a receiver with three receive antennas was placed into a different hole separated by 100 m from the transmitter. The pulse generator was based on a Marx generator with an LC filter, and for the receiver, the high-frequency data acquisition card was used, which can acquire signals using 3 Gigabytes per second. Used borehole antennas were designed to operate in the wide frequency band to ensure signal propagation through the soil. A deep regression convolutional network is proposed in this paper to estimate volumetric soil moisture using time-sampled signals. A regression convolutional network is extended to three dimensions to model changes in wave propagation between the transmitted and received signals. The training dataset was acquired during the period of 73 days of acquisition between two boreholes separated by 100 m. The soil moisture measurements were acquired at three points 25 m apart to provide ground truth data. Additionally, water was poured into several specially prepared boreholes between transmitter and receiver antennas to acquire additional dataset for training, validation, and testing of convolutional neural networks. Experimental results showed that the proposed system is able to detect changes in the volumetric soil moisture using Tx and Rx antennas.
Ključne besede: ground penetrating radar, cross-hole, L-band, deep learning, convolutional neural network, soil moisture estimation
Objavljeno v DKUM: 03.04.2024; Ogledov: 448; Prenosov: 36
Celotno besedilo (3,22 MB)
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