Browsing by Author "Ilbis, Erik, juhendaja"

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Nanosatellite Anatomy Analysis: The Second Generation of ESTCube
(Tartu Ülikool, 2017) Iakubivskyi, Iaroslav; Slavinskis, Andris, juhendaja; Ilbis, Erik, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond; Tartu Ülikool. Tehnoloogiainstituut
Any object that has been launched into orbit has experienced statical and dynamical loads during its travel through the atmosphere. The loads are of random nature and cannot be fully predicted as per real conditions. The structural requirements for ESTCube-2 have been determined as for the worst-case scenario, since the launch vehicle was not known at that stage of the project. A three-unit CubeSat will be subject to high-level sine and random vibration as well as shock response spectrum loading. Before physical testing, structural simulations were made and stresses were analysed in order to confirm the structural reliability and margins. Margins are essential in the design process due to uncertainties in the predicted vibration environment. In addition, the thesis presents the design of primary and secondary structures. As a result of this thesis, a final materials selection, topography optimisation, and manufacturing of the structure will be made. Moreover, the simulation results obtained here will be the subject of comparison with the physical testing results in the later stage of the ESTCube project. ESTCube-2 will be launched in the first half of 2019, and will serve as a testbed for the ESTCube-3 mission in the solar wind environment.
Prototype Design of Estcube-2 Electrical Power System Control Electronics
(Tartu Ülikool, 2015) Põder, Martin; Pajusalu, Mihkel, juhendaja; Ilbis, Erik, juhendaja; Tartu Ülikool. Loodus- ja tehnoloogiateaduskond; Tartu Ülikool. Tehnoloogiainstituut
The aim of this thesis was to build a prototype of ESTCube-2 EPS subsystem control electronics. For that purpose, ESTCube-1 EPS was analyzed from the hardware perspective and all the areas where improvements could be made were listed. The requirements for ESTCube-2 EPS control electronics were set and a new design was implemented that improves the functionality and the reliability of the system while making it more robust. The testing results showed that the prototype meets or exceeds all the requirements that were set. The main results are following: • the supply voltage of the system is 3.3 V; • power consumption of 14 mW was achieved which is less than the requested maximum of 30 mW; • the prototype has 30 external ADC input channels which are measured within a time window of 70 μsec. The number of the ADCs can be incremented with no increase in the acquisition time; • the system includes voltage fault detection system that notifies the MCU about the voltage fault and holds the system operational for about 200 milliseconds. The hardware module that was built during the practical work has two separate microcontroller units - one for general tasks and other for diagnostics purpose. The prototype features 3.3 V voltage regulator for obtaining supply from the USB port, pin headers between the main supply and individual sections supply lines as well as in the inputs and outputs of all peripheral devices, debugging LEDs and test points for convenient debugging. The module can be easily connected to other EPS subsystem´s prototypes. The low level software that was written utilizes direct memory access that allows high speed data connection between two microcontrollers. The software is written in C language and enables to reuse the high level software of the ESTCube-1 thanks to similar function arguments and return types.
Testing of Voltage Converters for the Electrical Power System of Estcube-2
(Tartu Ülikool, 2015) Raudheiding, Karl-Indrek; Pajusalu, Mihkel, juhendaja; Ilbis, Erik, juhendaja; Tartu Ülikool. Loodus- ja tehnoloogiateaduskond; Tartu Ülikool. Tehnoloogiainstituut
The goal for this work was to aid the process of designing EPS for ESTCube-2. The larger satellite needs more power and therefor the EPS of ESTCube-2 in not sufficient. During the process of this work following goals were achieved: *Easy to use testing platform to speed the testing of voltage converters was designed and manufactured; *Software to control and record data from this platform was designed; *The measurement range of the testing platform was validated and calibrated; *Four voltage converter testing modules were designed and manufactured; *Efficiency of these converters was measured; *Efficiency of these converters in load balancing mode was measured providing data of the efficiency of balancing circuit; The data collected from both tests provides valuable information for future tests. Based on current data, the best overall performance was seen with the LTC3603 voltage converter. The same chip also showed the smoothest performance with the load balancing circuit. The testing will continue after defending this thesis. Further testing must be concluded to determine parameters like converter output ripple, emission of EMI and behavior in temperature chamber.