This paper concerns the comparison of three linear reluctance actuators and four voice coil actuators for high-precision applications. The short-stroke actuators with reasonably low variation of the force are optimized on actuator mass and power dissipation. For actuators with a significantly high force variation, the configuration is modified with the objective to improve the actuator properties for high-precision applications. Finally, the comparison is made on performance regarding, force, mass, losses and stiffness.

This paper concerns the force density optimization for medium-stroke reluctance actuators applied in anti-vibration applications. The force density in a conventional E-core reluctance actuator is limited for medium strokes by the nonlinear force-displacement characteristic. In this paper, different tooth topologies are analyzed to maximize the force density along the stroke using the finite element analysis. Teeth parameters are tuned in each topology to analyze the influences on the force density. An analytic thermal model is used and verified with finite element simulations.

Magnetic hysteresis in the force of a prebiased E-core reluctance actuator is researched using three analysis methods. Simulations are performed with a 2-D/3-D finite-element method (FEM); and two semianalytic methods are evaluated, namely, a generalization of the classical Preisach model, which is combined with a dynamic magnetic equivalent circuit (MEC) method, and a complex impedance model, which is combined with a static MEC model. Ultimately, the FEM simulations and analytic models are examined by a comparison with force measurements performed with a piezoelectric load cell. Index Terms-Finite-element method (FEM), magnetic hysteresis, Preisach model, reluctance actuator.

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Magnetic hysteresis effects, present in the force of an E-core reluctance actuator, are examined by simulations and measurements. Simulations have been performed with a 3d finite element method (3d-FEM) and a Preisach model, which is extended with a dynamic magnetic equivalent circuit (MEC) model. Both simulation methods are first examined on the prediction of the magnetic flux density in a closed-and open toroid for dc-and ac excitations. Finally, both methods are used to predict the force of the E-core reluctance actuator, which is compared to ac force measurementsperformed with a piezoelectric load cell.

A measurement method is presented which identifies the magnetic hysteresis effects present in the force of linear reluctance actuators. The measurement method is applied to determine the magnetic hysteresis in the force of an E-core reluctance actuator, with and without pre-biasing permanent magnet. The force measurements are conducted with a piezoelectric load cell (Kistler type 9272). This high-bandwidth force measurement instrument is identified in the frequency domain using a voice-coil actuator that has negligible magnetic hysteresis and eddy currents. Specifically, the phase delay between the current and force of the voice-coil actuator is used for the calibration of the measurement instrument. This phase delay is also obtained by evaluation of the measured force and flux variation in the E-core actuator, both with and without permanent magnet on the middle tooth. The measured magnetic flux variation is used to distinguish the phase delay due to magnetic hysteresis from the measured phase delay between the current and the force of the E-core actuator. Finally, an open loop steady-state ac model is presented that predicts the magnetic hysteresis effects in the force of the E-core actuator.

Abstract-This paper concerns the requirement analysis and implementation of a measurement instrument which can identify the 3D magnetostriction strain. To measure magnetostriction, a high-accuracy magnetic flux density and strain measurement are required, while the mechanical stress in the sample is minimized. The Full Block Tester (FBT) is proposed as a measurement instrument. In this instrument, homogeneity of flux density within the measured sample and the strain measurement resolution are sufficient, but stress caused by magnetic forces is higher than required.

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