1. Event-triggered second-order sliding mode controller design and implementationAndrej Sarjaš, Dušan Gleich, 2023, original scientific article Abstract: 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. Keywords: event triggering, sliding mode control, super-twisted controller, chattering alleviation Published in DKUM: 07.12.2023; Views: 370; Downloads: 19 Full text (2,52 MB) This document has many files! More... |
2. PALETIRANJE IN PREIZKUŠANJE ZLEPNEGA SPOJA NA UMS2 : diplomsko deloIvan Verboten Mastnak, 2020, undergraduate thesis Abstract: V diplomskem delu je predstavljena dodelava obstoječega montažnega stroja UMS2, ki je produkt podjetja Vivapen d. o. o. Gre za napravo, ki preizkuša zlepni spoj med notranjo in zunanjo pušo ustnikov ter njihovo nadaljnjo manipulacijo v namenske zalogovnike. Opisana sta mehanski in električno-pnevmatski postopek načrtovanja stroja od ideje do končnega izdelka z vsemi pripadajočimi zahtevami in omejitvami. Diplomsko delo zajema modeliranje v SolidWorks-u, projektiranje električnih in pnevmatskih načrtov ter pisanje programa krmilnika v programskem okolju CyPro v povezavi z linijskim servo pogonom SMC. Na podlagi uspešno opravljene analize dobrih kosov, ki so produkt tega diplomskega dela, se je stroj aktivno vključil v proizvodnjo. Keywords: strojegradnja, EPLAN, CyPro, ACT Controller Published in DKUM: 03.11.2020; Views: 874; Downloads: 71 Full text (9,68 MB) |
3. Intelligent adaptive cutting force control in end-millingUroš Župerl, Franc Čuš, Edvard Kiker, 2006, original scientific article Abstract: In this article, an adaptive neural controller for the ball end-milling process is described. Architecture with two different kinds of neural networks is proposed, and is used for the on-line optimal control of the milling process. A BP neural network is used to identify the milling state and to determin the optimal cutting inputs. The feedrate is selected as the optimised variable, and the milling state is estimated by the measured cutting force. The adaptive controller is operated by a PC and the adjusted feedrates are sent to the CNC. The purpose of this article is to present a reliable, robust neural controller aimed at adaptively adjusting feed-rate to prevent excessive tool wear, tool breakage and maintain a high chip removal rate. The goal is also to obtain an improvement of the milling process productivity by the use of an automatic regulation of the cutting force. Numerous simulations are conducted to confirm the efficiency of this architecture. The proposed architecture for on-line determining of optimal cutting conditions is applied to ball end-milling in this paper, but it is obvious that the system can be extended to other machines to improve cutting efficiency. Keywords: end milling, adaptive force control, neuron controller, cutting conditions, adaptive control systems Published in DKUM: 12.07.2017; Views: 1289; Downloads: 136 Full text (3,43 MB) This document has many files! More... |
4. An ℋ∞ optimal robust pole placement with fixed transparent controller structure on the basis of nonnegativity of even spectral polynomialsAndrej Sarjaš, Rajko Svečko, Amor Chowdhury, original scientific article Abstract: This paper presents the synthesis of an optimal robust controller with the use of pole placement technique. The presented method includes solving a polynomial equation on the basis of the chosen fixed characteristic polynomial and introduced parametric solutions with a known parametric structure of the controller. Robustness criteria in an unstructured uncertainty description with metrics of norm ℋ∞ are for a more reliable and effective formulation of objective functions for optimization presented in the form of a spectral polynomial with positivity conditions. The method enables robust low-order controller design by using plant simplification with partial-fraction decomposition, where the simplification remainder is added to the performance weight. The controller structure is assembled of well-known parts such as disturbance rejection, and reference tracking. The approach also allows the possibility of multiobjective optimization of robust criteria, application of mixed sensitivity problem, and other closed-loop limitation criteria, where the common criteria function can be composed from different unrelated criteria. Optimization and controller design are performed with iterative evolution algorithm. Keywords: optimal robust controller, optimization, algorithm Published in DKUM: 15.06.2017; Views: 1101; Downloads: 374 Full text (3,03 MB) This document has many files! More... |
5. Controllership influences on the restructuring of Slovenian companiesDanijel Lebar, Iztok Kolar, 2015, original scientific article Abstract: Controllership, as an informational activity, is becoming a multidimensional function, about which numerous doubts exist as to whether to increase its independency and integrate it tightly with the decision-making process. Financial knowledge and business-analytical capabilities of carriers of controllership activity can offer support for operational, financial, and strategic restructuring. This is important when facing frequent business dynamics in order to enhance competitiveness and especially achieve short-term as well as strategic goals. Keywords: controllership, controller, restructuring, financial knowledge, business-analytical capabilities Published in DKUM: 03.04.2017; Views: 1309; Downloads: 376 Full text (431,15 KB) This document has many files! More... |
6. Position control with parameter adaptation for a nano-robotic cellGregor Škorc, Jure Čas, Simon Brezovnik, Riko Šafarič, 2011, original scientific article Abstract: This paper describes the development of a nano-assembly system, built up using linear piezo motors. The so-called nano-robotic cell is based on an X/Y manipulator, supported by three serving tables, movable within a Z axis, and aposition controlled using two different types of a bang-bang control methods. The presented application has been developed as a stand-alone application with the LabVIEW Real Time software package, a PCI-7356 servo controller card and a TMCM-090 stepper driver. Our experiments focused on two major problems present during the construction of nano-robotic assembly cells. The first one is a nonlinear characteristic of a linear piezo motor, which makes the use of classical control methods very limited. The second problem appears when a nano-robotic cell needs a bigger working space and at the same time, production demands that the manipulator moves more often over longer distances. In order to position in nano-resolution, the motors have to run at higher resolutions with smaller speeds. Therefore, long distance moves slow down the entire production process. Experiments on this system have shown that positioning within the nano-scale is possible, using a simple control method such as the bang-bang control method. Although positioning using this method is possible, certain limitations and weaknesses exists, making this simple method useless in nano-scale if higher speeds and longer move distances are needed. Certain changes in the basic control algorithm are proposed, which will ensure that the bangbang control method becomes useful within higher speeds and over longer distances. All recommendations are supported and backed- up by practical experimental results. Keywords: nanorobotske celice, nanopozicioniranje, histerezni krmilnik, proizvodnja MEMS, realno-časovni LabView, nano-robot cells, nano-positioning, bang-bang controller, MEMS assembly, LAbVIEW, real time Published in DKUM: 10.07.2015; Views: 1815; Downloads: 141 Link to full text |
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8. MIDI TECHNOLOGY AND COMPARISON BETWEEN KORG M50 AND MULAB MIDI SEQUENCINGVladimir Popovski, 2015, master's thesis Abstract: In the following research, a theoretical and practical analysis of MIDI technology will be presented, along with an in-depth comparasion between two types of sequencers: the integrated sequencer of the Korg M50 and the software sequencer of MuLab Free. The purpose of this thesis is, first, to introduce MIDI technology and its construction ,its individual parts, and its practical uses; and, second, to offer a comparation between the Korg M50 and MuLab Free, with the end goal being to aid future users of MIDI sequencers in choosing the appropriate sequencer for the appropriate situation. Keywords: MIDI, sequencer, korg, mulab, synthesizer, MIDI controller Published in DKUM: 05.06.2015; Views: 1483; Downloads: 144 Full text (4,79 MB) |
9. Rapid control prototyping using MATLAB/Simulink and a DSP-based motor controllerDarko Hercog, Karel Jezernik, 2005, original scientific article Abstract: A rapid control prototyping (RCP) system, based on commercially available software and custom in-house developed hardware is presented. An RCP system successfully combines the well-known simulation program MATLAB/Simulink and the custom DSP-based floating point motor controller. An RCP system provides smooth and fast transition from off-line simulation in Simulink to real-time operation on the embedded motor controller. On-the-fly parameter tuning and data visualization are provided in addition to rapid code generation. The presented solution represents a powerful, versatile and portable RCP system especially suitable for educational processes as well as motor control research. This article is supplemented by an example of cascade DC motor control. Keywords: control education, control experiments, rapid control prototyping, DSP controller Published in DKUM: 01.06.2012; Views: 2429; Downloads: 70 Link to full text |
10. Electrohydraulic pressure control by a self-adjusting proportional derivative controllerDarko Lovrec, Friedrich Faber, 2006, original scientific article Abstract: The main characteristic of an electrohydraulic pump control system is the presence of an electrical signal path. It requires at least one sensor for the controlled value (in this case pressure), delivering feedback to be compared with the electrical or numerical reference in the controller. The additonal expense penalty for the sensor and the valve is offset by the advantage of flexibility in the structure and parameters of the controller in comparison to hydraulic - mechanical concepts. Thus, the transfer response can be adapted to demands, even in the operational state. Sophisticated control structures can be implemented easily in the form of computer or microcontroller programs. The layout of electrohydraulic pressure control discussed in this study includes the presented loading unit. The variable pump is designed to act together with a proportional valve having two metering edges. It is less expensive compared to the design with a synchronizing cylinder and four metering edges. However, only inferior static and dynamic performance can be expected. Hydraulic energy is supplied to the control valve directly from the output port of the pump - with the advantage of simple assembly, as there are no additional components required - but with the drawback that there is influence on the control loop`s properties at every change in the disturbance value or reference. The aim of the study presented in this paper is a more efficient and simple concept compared to other known methods for pressure control of the above mentioned pump including the dynamics of the distribution network, and also the characteristics of the hydraulic load with special focus on improvements in steady state and dynamic behaviour. Keywords: automatic control engineering, electrohydraulic systems, pressure control, self-adjusting proportional controller Published in DKUM: 31.05.2012; Views: 2291; Downloads: 142 Link to full text |