A continuing task in engineering is to increase the reliability, availability and safety of technical processes and to achieve these fault diagnosis becomes an advanced supervision tool in the present industries. Vibration in rotating machinery is mostly caused by unbalance, misalignment, shaft crack, mechanical looseness and other malfunctions. The objective of this paper is to propose a model...

The magnetically suspended Control Moment Gyroscope (CMG) has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this pape...

This paper describes the numerical analysis of a stall suppression system for helicopter rotors. The analysis employs a finite element method and includes advanced dynamic stall and vortex wake models. The stall suppression system is based on a transfer function matrix approach and uses blade root actuation to suppress stall directly. The rotor model used in this investigation is the UH-60A rot...

Friction between contacting surfaces of metal materials restricts the application of mechanical support in the high-precision inertial device of a rotational gyroscope. Instead, a diskor ring-shaped rotor is electrostatically or magnetically suspended. However, stability of the rotor suspension restricts further improvement of the measurement precision. In the developed rotational gyroscope, a ...

Abstract This paper presents a nonlinear compensation technique to solve the trajectory tracking problem for a quadrotor. The kinematics and dynamic equations are obtained using Lagrange –Euler principle. The proposed control algorithm is robust to pay load variations even at high speed or low speeds. The controller can compensate the complex dynamics and also other external disturbances. The t...

Current trends in micro-turbomachinery stress the need for adequate rotordynamic models. These models should allow accurate prediction of critical speeds, imbalance response and stable operation range of microturbomachinery rotor-bearing systems. This paper gives an overview of the total rotordynamic modelling process of a micro-turbine rotor supported on aerostatic bearings. A both accurate an...

Antti Kärkkäinen Dynamic Simulations of Rotors during Drop on Retainer Bearings Lappeenranta, 2007 91 p. Acta Universitatis Lappeenrantaensis 279 Diss. Lappeenranta University of Technology ISBN 978-952-214-444-7; ISBN 978-952-214-445-4 (PDF) ISSN 1456-4491 The active magnetic bearings have recently been intensively developed because of noncontact support having several advantages compared to c...