Mechanically coupled high dynamic linear motors - a new design approach and its control strategy

Improved drive dynamics decisively boost productivity and accuracy of machine tools. Linearmotors have advantages to overcome drawbacks of electromechanical drives, but are limited by their power density. Reaction forces of linear motors cause undesired excitation of the machine structure. Current research approaches focus on impulse decoupling and compensation as well as on force reduction. The paper presents a new design approach, characterised by two mechanically coupled and opposite driving linear motors. This arrangement improves the static and dynamic properties by force distribution which leads to an impulse-free feedback system. In order to have an effective use of the gained dynamics various control structures for coupled drives are investigated. Tuning methods as well as simulation and experimental results are discussed.