How homing pigeons (Columba livia) return to their loft from distant, unfamiliar sites has long been a mystery. At many release sites, untreated birds consistently vanish from view in a direction different from the home direction, a phenomenon called the release-site bias. These deviations in flight direction have been implicated in the position determination (or map) step of navigation because...

Magnetic bearings are increasingly being used for a large variety of applications. Their unique features make them attractive for solving classical rotor-bearing problems in a new way and allow novel design approaches for rotating machinery. Classical limitations can be overcome and feature ranges can be extended. Of course, limitations still hold, imposed by principally valid physical constrai...

A design process comprising aspects of modelling and analysis is developed, implemented and verified for a flexible rotor active magnetic bearing system. The system is specified to experience the first three critical frequencies up to an operating speed of 10,000 rpm. Rotor stability at critical frequencies places specific constraints on the equivalent stiffness and damping parameters of the ac...

Active magnetic bearings require some form of control, based on feedback of the position of the suspended object, to overcome open–loop instability and to achieve targeted system performance by modifying the bearing dynamics. In many applications of magnetic bearings, a need to eliminate discrete position sensors may arise either from economic or reliability considerations. Magnetic bearings wh...

Active magnetic bearings enable contactless operation and can therefore be used for supporting rotors spinning at high speeds. However, the rotational speed in conventional reluctance-force-based magnetic bearing topologies is limited, which is mainly due to high rotor losses and limited force control bandwidths. In this paper, a prototype of a self-bearing motor is presented, which overcomes s...

Usually magnetic bearing consists of an actuator and a levitated object which can be either the rotor of a motor or any other ferromagnetic body. For proper function and to provide stable support, the actuator needs an accurate information about the position of the levitated body which must be given by a sensor. In many applications the displacement sensor with associated wires and cost to be a...

One of the chief obstacles to constructing a reliable, low-cost, practical magnetic bearing is designing a suitable position sensor. A homopolar magnetic bearing that uses the same coils to stabilize the rotor and sense its position is introduced. A prototype bearing has been built and successfully used to stabilize a rotor. The electromagnetic analysis of the self-sensing function, the impleme...