C.M.M. van Lierop

Modeling of Magnetically Levitated Planar Actuators With Moving Magnets

This paper presents three types of magnetostatic models of ironless planar actuators with moving magnets. The models predict the force and torque exerted on the translator of the actuator, which can be positioned in six degrees-of-freedom with respect to the stator coils. The force and torque are calculated with the Lorentz force law. The analytical and numerical models can be used for the design of large planar actuators, for the fast comparison of actuator topologies, and in the decoupling and commutation algorithm. The models have been verified with experiments

Magnetically Levitated Planar Actuator With Moving Magnets

This paper concerns the design, optimization, and commutation of a six-degree-of-freedom planar actuator with an active magnetic bearing. The planar motor has a stationary coil array and a translator with a Halbach magnet array. During movements in the plane, the set of energized coils changes with the position of the translator. In this paper, a method for the electromagnetic design of this type of actuator is discussed, and several topologies are compared. The best performing topology in terms of power dissipation and force and torque ripples has been manufactured and successfully tested.

Magnetically Levitated Planar Actuator with Moving Magnets

This paper concerns the design, optimization and commutation of a six degree-of-freedom planar actuator with active magnetic bearing. The planar motor has a stationary coils array and a translator with a Halbach magnet array. During movements in the xy-plane, the set of energized coils changes with the position of the translator. In this paper a method for the electromagnetic design of this type of actuator is discussed and several topologies are compared.

Model-Based Commutation of a Long-Stroke Magnetically Levitated Linear Actuator

This paper concerns a commutation and switching algorithm for multi-degree-of-freedom moving-magnet actuators with permanent magnets and integrated active magnetic bearing. Because of the integration of long-stroke actuation and an active magnetic bearing, DQ-decomposition cannot be applied. Therefore, these actuators are a special class of synchronous machines. A newly developed model-based commutation algorithm for linear and planar actuators enables long-stroke motion by switching between different sets of coils. Moreover, the ohmic losses in the coils are minimized. Three different versions of the algorithm are compared and successfully implemented on a 3-DOF magnetically levitated linear actuator

Ironless magnetically levitated planar actuator

This paper describes a magnetically levitated planar actuator with moving magnets. This ironless actuator has a stationary coil array above which a translator with a permanent-magnet array is levitated and propelled in the xy plane. During the movements in the xy plane, the set of active coils is switched, as a result of which the stroke in the xy plane can be made, in principle, infinitely long. Measurements on the realized planar actuator show the feasibility of this concept.

Control of multi-degree-of-freedom planar actuators

This paper concerns a control-oriented analysis of a new commutation strategy which overcomes the limitations of dq0-decomposition for ironless multi-DOF planar actuators with integrated magnetic bearings. The new strategy minimizes the losses and allows for smooth switching of active coils while maintaining the decoupling of all degrees of freedom. Moreover, the method can also include the edge effects of the magnet-array which is not possible with dq0-transformation. The proposed controller has been implemented on a 3-DOF actuator which elucidates the good performance. When adding constraints to the new algorithm, multi-phase behavior can be achieved, which is suitable for multi-phase amplifiers

Analytical model of a magnetically levitated linear actuator

This paper concerns an analytical model of an iron less, magnetically levitated, three degree-of-freedom linear actuator, as a pre-prototype of a six degree-of-freedom planar actuator. The actuator has moving magnets and stationary coils. The translator with the magnets is repelled by the coils. The forces and torques exerted by a stator coil on the array of permanent magnets have been calculated analytically and compared with measurements and numerical predictions. The same approach can be applied to model an ironless planar actuator.

Design and test of an ironless, three degree-of-freedom, magnetically levitated linear actuator with moving magnets

This paper concerns the design and test of a ironless three degree-of-freedom linear actuator. The motor consists of stationary coils and a translator with permanent magnets. The translator is magnetically levitated (z-direction) and provides long-stroke motion along the x-axis and limited rotation about the y-axis. The three degree-of-freedom motor is a preliminary study for a six degree-of-freedom planar motor. The actuator is designed using a tool, which is based on the analytical magnetic field solution of a permanent magnet and numerical integration over the coil volumes. Both force and EMF measurements and finite element analysis show the accuracy of the design tool