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Item Electronic system for controlled modification of temperature field in sheet metal blanks(University of West Bohemia, 2019) Holota, Radek; Koucký, Václav; Krist, Petr; Valenta, Pavel; Mašek, BohuslavTechnology for modifying the local temperature of a material is tested for hot forming. A system for selective controlled cooling was designed for this purpose and a workplace enabling heating, local cooling and material forming was built. This paper describes the principles and possibilities of the local cooling unit, control methods and measurement of the temperature fields.
Item Rack mounted low-profile indirect frequency converter(University of West Bohemia, 2019) Glasberger, Tomáš; Košan, Tomáš; Molnár, JanA new indirect frequency converter is introduced in this paper. The main goal of the new proposal is to simplify installation and running as supply unit for industrial applications. It fulfills minimum dimensions requirement and also enables parallel connection and full energy recuperation mode. The proper function of the designed converter has been performed on a prototype of linear actuator for a 6DOF motion platform.Item Converter power losses computation by FPGA-based HIL simulator(University of West Bohemia, 2019) Dragoun, Jaroslav; Talla, Jakub; Košan, TomášConverter losses play a crucial role in the process of power converter design. Especially semiconductor components and heat sink selection are strongly dependent on the total power converter losses and thus affect the power converter size and its price. The most popular techniques for determination of the losses are based on the computer simulation of the power converter. These kinds of simulations could be very time consuming, because on one side, the simulation needs very short steptime for differential equations calculation to model power converter switching. On the other side, the temperature dynamics of heat sink are commonly slow and depend on power cycles of converter. With the help of FPGAbased hardware in the loop (HIL), the simulation could run real-time and it is possible to test different scenarios, different modulation techniques and see their influences on converter losses. This approach can lead to reduction of losses to the state, when it is possible to reduce the size of converter. Furthermore, the HIL simulation could be used for testing and developing control algorithm in real time conditions. It also offers flexibility in the easy change of model parameters and monitoring values which are not or hardly obtainable in real machine. This paper presents the FPGA-based HIL simulator of induction motor drive with three phase voltage source inverter based on Semikron IGBT modules.Item Adaptive control system for autonomous vehicle path following(University of West Bohemia, 2019) Štork, Milan; Pinker, Jiří; Weissar, PetrAutonomy in vehicles is a rapidly expanding technology that is of interest in many major car companies. Autonomous driving enables safer journeys by removing human error in driving, as well as reducing driving time and fuel consumption by optimizing the engine and brake actuation. While certain autonomous functions in cars have been in use for over a decade, such as lane keeping and automatic parking these features are subject to specific scenarios. A fully automated vehicle needs to take into account the unpredictable and complex environments that cars drive in. The idea of a self-driving car in a city environment needs specific requirements such as reliable path following, accurate sensor data and safe drive. The scope of this paper is to create a simple path following solution which enables an autonomous car to accurately traverse along any given path.Item Assessment of three multiple cuff blood pressure devices(University of West Bohemia, 2019) Jílek, Jiří; Štork, MilanShortcomings of single cuff blood pressure devices have led to research of devices with more than one cuff for improved accuracy. We assessed two devices that use two cuffs and one device that uses three cuffs. The devices with two cuffs use one occluding arm cuff and one cuff that detects pulses that pass past the occluding cuff. The device with three cuffs uses pulse delay time. The advantages and the shortcomings of the devices are discussed in this paper.Item Modified tellegen principle used for power and energy systems modeling(University of West Bohemia, 2019) Štork, Milan; Mayer, DanielThe paper deals with a problem of modeling of dynamic systems. The proposed approach to the problem solution is based on modified Tellegen’s theorem well known from electrical engineering. The novelty of this approach is that it is based on the instantaneous power calculation for real linear and nonlinear systems e.g. electrical circuits, mechanical systems, heat transfer etc. Consequently, mathematically as well as physically correct results are obtained. Some known and often used system representation structures are discussed from the developed point of view as an addition. The examples are also included. The mathematical derivation and results of simulations are presented in this paper.Item A novel ZCS/ZVS bidirectional DC-DC converter for energy storage applications(University of West Bohemia, 2019) Bhajana, V.V.Subrahman. Kumar; Drábek, PavelIn this paper, a new soft-switched non-isolated bidirectional converter is proposed. This proposed converter is operated with soft-switching (zero current switching / zero voltage switching). It is implemented during the turn-on of main switching devices, with the addition of auxiliary resonant circuit that consists of an auxiliary switch, diode, capacitor and an inductor. The switching losses are significantly reduced due to soft-switching operation of the main switches. Therefore, the efficiency of this topology is improved. The additional benefit of this topology is that the auxiliary switches are also operated with soft-switching. The proposed topology observes ZCS turn-on for boost mode and ZVS turn-on for buck mode operations. The principles of operation, design analysis and simulation verifications are discussed in detail. The soft-switching capabilities are obtained from design simulations on the 150V/250V/500W converter system.Item Multidimensional cross parity check codes as a promising solution to CubeSat low data rate downlinks(University of West Bohemia, 2019) Veřtát, Ivo; Dudáček, LuděkSimple cross parity check codes have been well known for decades in the areas of magnetic recording and radiation-hardened memory in space applications. However, the computational power requirements of higher dimensional cross codes mean that priority has been given to different forward error correction methods, with the result that cross parity check codes have not become sufficiently generalized to include a higher number of dimensions. In the last two decades, the focus has mainly been on Reed-Solomon codes, Hamming codes, BCH codes, convolutional codes and turbo codes. In this paper, the issues behind generalized multidimensional parity check codes are explored again in relation to current main-stream interest by covering parity check codes in the form of low-density parity checks. I will put forward a new solution to the multidimensional parity check code decoding process for low data rate downlinks in CubeSat satellites. I propose that the high computational power of software-defined radio can be utilized for iterative decoding of CubeSat satellite transmissions in ground control segments, ensuring that onboard multidimensional parity encoders are as simple to use as possible.Item Models of physiological parameters for runners and cyclists(Springer Nature Singapore Pte Ltd., 2019) Štork, Milan; Novák, Jaroslav; Zeman, Vaclav
Item Indirect cardiac output and stroke volume assessment during spiroergometric examination(Springer Nature Singapure Pte Ltd., 2019) Novák, Jaroslav; Štork, Milan; Zeman, Václav
