Iskanje po katalogu digitalne knjižnice

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: 7
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: 40
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: 26
Celotno besedilo (3,22 MB)
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Opis: The paper presents an event-triggered higher-order sliding mode controller design. The event-triggering technique is the alternative approach to real-time controller execution, unlike the classic time-triggering technique, which is not time-dependable and is governed by the triggering policy. The technique is suitable for system resource relaxation in case of computation burden or network usage mitigation. The paper describes the stability analysis of the super-twisted sliding mode controller based on input-to-state stability notation. The stability analysis introduces a triggering policy related directly to the ultimate boundness of the system states and preselected sliding variables. The controller time execution with the selected triggering condition prevents the exhibition of the Zeno phenomena, where the minimal inter-event time of the controller has a positive non-zero lower bound. The minimal value of the inter-event time is related directly to the controller parameters and triggering bound, the selection of which is given with the derived stability conditions regarding the designer’s objective. Preventing the fast nonlinear controller execution, especially close to the sliding manifold, also alleviates the chattering phenomena effectively, which is a primal drawback, and limits the usage of the controller on various systems. The method’s efficiency is verified with the hardware-in-the-loop system, where the dynamic and robustness of the triggering approach are compared to the standard time-triggered execution technique.
Ključne besede: event triggering, sliding mode control, super-twisted controller, chattering alleviation
Objavljeno v DKUM: 07.12.2023; Ogledov: 370; Prenosov: 21
Celotno besedilo (2,52 MB)
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Opis: V diplomskem delu sta opisana načrtovanje in implementacija adaptivnega regulatorja na realnem sistemu prve stopnje ter primerjava s klasičnimi regulatorji. Regulacija se izvaja v programu MATLAB, parametri adaptivnega regulatorja se določijo z MIT-pravilom. Realni sistem predstavljata mikroračunalnik STM32 Nucleo, na katerem poteka regulacija, in grelnik, na katerega je priključen senzor temperature.
Ključne besede: adaptivni regulator, MRAS, adaptivno vodenje
Objavljeno v DKUM: 05.10.2023; Ogledov: 321; Prenosov: 40
Celotno besedilo (2,61 MB)