Practical Application of a Magnetic Bearing and Linear Propulsion Unit for Six Degrees of Freedom Positioning

This paper describes a system for positioning a body in six degrees of freedom by using three electromagnetic units for suspension and linear propulsion. The X-position and the V-position can be controlled over a range of 10 mm. The Zposition can be controlled over a range of 1 mm. Angles around X Y and Z can be controlled over a range of 5,5 and 50 mrad, respectiv.ely. A single Suspension and linear Propulsion unit (SPU) is an active magnetic suspension (bearing) system combined with a lineae magnetic propulsion system. Firstly, this paper describes the principle of operation of an SPU. It will show how a stable magnetic bearing has been constructed and how propulsion in the direction perpendicular to the suspension direction is achieved. Attention will be paid to the interaction between the suspension and t he propulsion forces. This interaction must be minimised for maximum system performance. The second part of this paper will concentrate on the application of three SPU's in a system for positioning in six degrees of freedom.