Author, Institution: Gražvydas Kazokaitis, Kaunas University of Technology
Science area, field of science: Technological Sciences, Mechanical Engineering, T009
Scientific Supervisor: Prof. Dr. Vytautas Jūrėnas (Kaunas University of Technology, Technological Sciences, Mechanical Engineering, T009)
Dissertation Defence Board of Mechanical Engineering Science Field:
Dr. Rolanas Daukševičius (Kaunas University of Technology, Technological Sciences, Mechanical Engineering, T009) – chairman
Habil. Dr. Algimantas Bubulis (Kaunas University of Technology, Technological Sciences, Mechanical Engineering, T009)
Prof. Dr. Sergėjus Borodinas (Vilnius Gediminas Technical University, Technological Sciences, Mechanical Engineering, T009)
Habil. Dr. Evgeniya Korobko (Luikov A.V. Heat and Mass Transfer Institute, Academy of Sciences of Belarus, Technological Sciences, Material Engineering, T008)
The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).
An overview and problematic of existing attitude control systems and mechanisms for small satellites (nanosatellites) is presented in this dissertation. A design of 3-DOF piezoelectric actuator with spherical magnetic rotor is proposed for small CubeSat-type satellites as a possible solution for attitude control systems. Such system combines the advantages of passive and active attitude control systems.
Numerical and experimental models of the drive, and the results of experiments and simulations of resonant operating frequencies is presented in this paper. Possible unimorph design of the drive, when the piezoelectric actuator is combined with the metal flange, and its impact to the dynamic characteristics of the drive are considered.
Also, this dissertation presents the results of experiments and measurements, of electrical impedance and the displacements and motion trajectories of active contact point of the piezoelectric actuator, the resolution of rotational motion of the rotor is investigated.
In a last chapter of the dissertation a numerical study of integration of a magnetospheric piezoelectric drive into an existing ESTCube-1 satellite is presented. The aim of these studies is to replace the existing attitude control system with a magnetospheric piezoelectric drive, reducing the occupied volume and mass of the used mechanism. This section also presents the possible layout of the sensors for measurement of magnetic field strength, and the feedback algorithm to control the drive.