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Analysis, Implementation and Utilization of the Vold-Kalman Filter for Non-Stationary Signals
Čala, Martin ; Tůma, Jiří (referee) ; Žiaran,, Stanislav (referee) ; Beneš, Petr (advisor)
The doctoral thesis focuses on a Vold-Kalman filter (VKF). Theoretical part describes properties of VKF and other order tracking methods, namely computed order tracking (COT) and Gabor order tracking (GOT). It also characterizes requirements for rotational speed measurements as one of the key elements for correct functionality of VKF. Practical part depicts own filter implementation and its properties. Main stress is put on computational efficiency, that is in result better than in available codes. Thesis also points out possible issues with numerical instabilities within calculation caused by limited dynamic range of double data type. This is solved by restricting the inputs to prevent the instabilities. Restriction is applied also to cases where the result is numerically correct but unusable. Following part extends the comparison with methods STFT, COT and GOT, where benefits of VKF for nonstationary conditions are shown. The last section shows given information used on simulated signals. This is then applied to show mentioned techniques on experimental data, for instance from turbo engine or electric motor, where the ability of VKF in checking the accordance between speed profile and vibration data is illustrated.
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Complex Analysis of Modal Properties of Rotating Electrical Machines
Donát, Martin ; Vlach, Radek (referee) ; Žiaran,, Stanislav (referee) ; Dušek, Daniel (advisor)
This dissertation thesis deals with the computational modelling of the dynamic response of the rotating electrical machine structure on the application of the magnetic forces. Apart from the dynamic response of the ideal symmetrical machine, the influence of the air gap eccentricity on the dynamics response is studied in this work. A basic type of the air gap eccentricity, which is caused by eccentric mounting of the rotor pack on the shaft of the rotor, is considered. The calculations the dependence of the magnetic forces on the time and a misalignment of the rotor pack are performed as first. The computational model of the magnetic field of the rotating electrical machine, which is based on solution of the electromagnetic coupled field analysis by finite element method, is used for this purpose. An analysis of the influence of the unbalanced magnetic pull and the stiffness of some parts of the machine on the modal properties of the machine is performed in the second part of this thesis. A third part of this thesis is focused on the calculation of the dynamic response of the machine during the steady state operation of the machine and the influence of the rotor pack misalignment on the dynamic response is studied. The obtained results showed that the tangential components of the magnetic forces, which act on the stator pack, excite significant torsional vibration of the stator. Besides the vibration of the stator of the machine, the influence of the rotor pack misalignment on the sound power of the machine, vibration of the rotor, loads of rotor bearings and air gap eccentricity is studied in this thesis.
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Analysis, Implementation and Utilization of the Vold-Kalman Filter for Non-Stationary Signals
Čala, Martin ; Tůma, Jiří (referee) ; Žiaran,, Stanislav (referee) ; Beneš, Petr (advisor)
The doctoral thesis focuses on a Vold-Kalman filter (VKF). Theoretical part describes properties of VKF and other order tracking methods, namely computed order tracking (COT) and Gabor order tracking (GOT). It also characterizes requirements for rotational speed measurements as one of the key elements for correct functionality of VKF. Practical part depicts own filter implementation and its properties. Main stress is put on computational efficiency, that is in result better than in available codes. Thesis also points out possible issues with numerical instabilities within calculation caused by limited dynamic range of double data type. This is solved by restricting the inputs to prevent the instabilities. Restriction is applied also to cases where the result is numerically correct but unusable. Following part extends the comparison with methods STFT, COT and GOT, where benefits of VKF for nonstationary conditions are shown. The last section shows given information used on simulated signals. This is then applied to show mentioned techniques on experimental data, for instance from turbo engine or electric motor, where the ability of VKF in checking the accordance between speed profile and vibration data is illustrated.
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Prediktory správania v eticky senzitívnych situáciách v kontexte manažérskeho rozhodovania =: predictors of behavior in the ethically sensitive situations in the context of managerial decision-making /
Žiaran, Pavel
The work has for objective to search for predictors of decision-making in ethically sensitive situations. As possible predictors the following aspects were analyzed: personality traits (measured by the Hexaco test, prosocial values (measured by simple economic experiments ultimatum and dictator). The behavior was analyzed in the frame of a behavioral experiment in the form of simulation game in two rounds (ethically sensitive situation and situation without an ethical proble). 189 undergraduate students of business took part in the experiment, out of which 154 were included in the analysis. As a result is a proposition of a simple algorithm to predict begavior in the ethically sensitive situations in the managerial context. Prediction is based on: (1) combination of results in economic experiments ultimatum and dictator and (2) combination of results in the personality traits of h-factor (Honsety-Humility) of the Hexaco-60 personality test. The results represent a contribution for the human resource management, in the frame of personnel selection, as regards working positions with high demands on ethical standards of the applicant.
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Complex Analysis of Modal Properties of Rotating Electrical Machines
Donát, Martin ; Vlach, Radek (referee) ; Žiaran,, Stanislav (referee) ; Dušek, Daniel (advisor)
This dissertation thesis deals with the computational modelling of the dynamic response of the rotating electrical machine structure on the application of the magnetic forces. Apart from the dynamic response of the ideal symmetrical machine, the influence of the air gap eccentricity on the dynamics response is studied in this work. A basic type of the air gap eccentricity, which is caused by eccentric mounting of the rotor pack on the shaft of the rotor, is considered. The calculations the dependence of the magnetic forces on the time and a misalignment of the rotor pack are performed as first. The computational model of the magnetic field of the rotating electrical machine, which is based on solution of the electromagnetic coupled field analysis by finite element method, is used for this purpose. An analysis of the influence of the unbalanced magnetic pull and the stiffness of some parts of the machine on the modal properties of the machine is performed in the second part of this thesis. A third part of this thesis is focused on the calculation of the dynamic response of the machine during the steady state operation of the machine and the influence of the rotor pack misalignment on the dynamic response is studied. The obtained results showed that the tangential components of the magnetic forces, which act on the stator pack, excite significant torsional vibration of the stator. Besides the vibration of the stator of the machine, the influence of the rotor pack misalignment on the sound power of the machine, vibration of the rotor, loads of rotor bearings and air gap eccentricity is studied in this thesis.
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