Universiẗat, Diss., 2006--Braunschweig.

Stuttgart, Univ., Diss., 2003. / Druckausg. im VDI-Verl., Düsseldorf erschienen.

Thesis (doctoral)--Universität Bremen, 2006. / Includes bibliographical references.

The original idea of the thesis was realized to control the electric drive of the rotor with a special feature. Without using a complex mechanism, the angle of each blade of the rotor can be controlled individually. The blades are fixed independently to a permanent magnet and the housing encompassing the rotor contains coils. By powering the coils, the whole rotor turns into a permanent magnet motor and by using a control algorithm, each blade can be separately driven. In the first chapter, the introduction to the main idea of the research project is described along with working principle of rotor blade. The basic concept of blade angle is introduced. The second chapter is the state of Technique. In this chapter, the working principle and basics of permanent magnet synchronous machine and brushless motor with mathematical model is described. Also, space vector pulse width modulation and double acting piezoelectric actuator model for helicopter rotor are explained. The third chapter is the overall description of the initial status of the research project. This part includes the basic principle of the control system, sensorless field-oriented control of Permanent Magnet Synchronous Machine (PMSM). Also, the motor parameters calculated from the python script of motor design are listed in tabular form. The fourth chapter focuses on control strategy implementation. First of all, the criteria for selecting the microcontroller are described. After that, the structure of the program with a flow chart was explained. Also, a short description is mentioned of how space vector pulse width modulation is applied. The main function of the position and speed controller with block diagram is explained. Moreover, back-EMF based observer and EKF-based observer are described. In the fourth chapter, the initial problem of the research project is discussed. To overcome this problem, a set of experiments is carried out. In the last chapter, the result of the experiment with proper explanation is summarized. Further on the future work to solve the problem is listed.

Ziel dieser Arbeit war es zu erforschen, ob mittels einer strukturierten Anamnese und einer intensiven manueller Untersuchung ein Weg zur Prävention von Rückenschmerzen und einer möglicherweise daraus resultierenden Berufskrankheit zu finden ist. Je 20 männliche Hubschrauberpiloten und Bordmechaniker des Transporthubschrauberregimentes 30 im Alter von 25-50 Jahren bildeten die Untersuchungsgruppen. Sie alle sind Teil der Besatzungen auf der Bell UH-1D, einem seit 1965 in der Bundeswehr ein-geführtem Hubschrauber mit einem Triebwerk und 2 Rotorblättern, wodurch sehr starke und niederfrequente Vibrationen erzeugt werden. Grundlagen der Untersuchungen waren ein validierter und standardisierter Erhebungsbogen, eine umfassende manuelle Untersuchungstechnik sowie eine genaue Kenntnis der Arbeitsplätze von und Anforderungen an Hubschrauberbesatzungen des Heeres auf Bell UH-1D. Die Untersuchungen erfolgten jeweils ohne Kenntnis der Anamnese nach den vorgegebenen Schritten des Untersuchungsbogens / Diagnostics and prevention of back pain in German Bundeswehr helicopter aircrews on Bell UH1D; differentiation and prevention of back pain and potential occupational diseases; An attempt to verify and evaluate back pain with manual diagnostic (chirodiagnostics and chirotherapy)and structured medical history in order to prevent pain and occupational diseases.

This paper presents the development of a helicopter axial piston pump model with condition monitoring in mind. Industrial constraints and needs ask for modelling with a lumped-parameter approach and require model architecture to be addressed with care. The aim of the proposed model is to assess the merits of pump leakage monitoring through measurement of case pressure. Once reviewed the state of the art in pump modelling, the slipper/swashplate interface is taken as an example to propose and implement in Simcenter AMESim a variable gap height model. The simulation results show that commonly used lumped-parameter models overestimate leakage. It also points out that average leakage at slipper may reverse at high pump displacement.