Sensors and Actuators A 148 (2008) 319–328 Contents lists available at ScienceDirect Sensors and Actuators A: Physical journal homepage: www.elsevier.com/locate/sna Contactless power supply for moving sensors and actuators in high-precision mechatronic systems with long-stroke power transfer capability in x–y plane J. de Boeij ∗ , E. Lomonova, J.L. Duarte, A.J.A. Vandenput Eindhoven University of Technology, Department of Electrical Engineering, PO Box 513, 5600 MB Eindhoven, The Netherlands article info Article history: Received 28 January 2008 Received in revised form 31 July 2008 Accepted 1 August 2008 Available online 27 August 2008 Keywords: Contactless energy transfer Mechatronic systems Inductive coupling Moving load abstract In this paper, a new topology for contactless energy transfer is proposed and tested that can transfer energy to a moving load using inductive coupling. This contactless energy transfer topology is designed to supply power to the moving parts in high-precision mechatronic systems without cable slabs. The proposed topology provides long-stroke contactless energy transfer capability in the x–y plane and a short-stroke movement of a few millimeters perpendicular to the plane. In addition, it is tolerant to rotations. The electrical steady-state, electrical transient, combined electrical and mechanical transient and forces of the contactless energy transfer system are modeled. The experimental setup consists of a platform with one secondary coil, which is attached to a linear actuator. Underneath the platform is an array of primary coils, that are each connected to a half-bridge square wave power supply. The load on the secondary side is a rectifier with a 50  resistor. The energy transfer to the load is measured while the secondary coil is moved over the array of primary coils by the linear actuator. The secondary coil moves with a stroke of 18cm at speeds over 1m/s, while up to 265W of power is transferred continuously with 90% efficiency. The proposed system is very suitable for transferring energy without cable slab to planar actuators and to conventional linear (short- and long- stroke) actuators in high-precision motion systems, such as lithography, die-bonding and component placement machines. © 2008 Elsevier B.V. All rights reserved. 1. Introduction In high-tech mechatronic systems, a cable slab to the moving part of the machine is a source of disturbances. It introduces fric- tion, stiffness and damping and limits the stroke of the mover. In addition, the cables break after a certain number of movements due to the strains induced by the motion, resulting in machine failures. The cable slabs are necessary to provide power to the mover and to exchange information between the moving part and the controller, which is located on the fixed world. This disadvantage is especially important in systems with air bearings or with a magnetic suspen- sion, which can move without mechanical contact if the cable slab could be omitted [1,2]. To omit a cable slab, both the energy transfer and information exchange should be made wireless. Contactless energy transfer (CET) is possible by means of an inductive coupling and several wireless techniques are available for sending information, e.g. radio modulation, infrared and laser. To test these techniques, a contact- less planar actuator with manipulator is studied as shown in Fig. 1. ∗ Corresponding author. Tel.: +31 402473412; fax: +31 402434364. E-mail address: j.d.boeij@tue.nl (J. de Boeij). It consists of a contactless planar actuator with moving magnets over an array of suspension coils combining magnetic suspension and propulsion with a manipulator on top of the floating platform. The energy transfer to the moving platform is done by means of an inductive coupling between the fixed primary coils and the moving secondary coil. The aim of this research project is to transfer energy to the moving platform continuously and at every position in order to enhance the functionality of the platform, while maintaining the advantages of operating without contact and cables slabs, which is necessary to reach submicron precision. Previously presented methods for contactless energy transfer suffer from limited stroke, cannot supply energy at every position or cannot deal with moving loads. The systems discussed in Refs. [3,4] require that the primary and secondary coil are aligned and that they can tolerate only slight misalignments of the center axes of the coils, which makes them suitable for rotational movement only. Contactless energy transfer from a stationary part to translating part is also feasible either by using elongated coils with cores as dis- cussed in Ref. [5], a grid of primary coils [6–8] or by using charging bays [9,10]. These systems either have the disadvantage of limited stroke in the case of elongated coils or they cannot supply energy at every possible position. 0924-4247/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2008.08.012