Positioning system and lithographic projection apparatus

A lithographic apparatus has a positioning system for positioning an object table, said positioning system comprising a planar motor having a stator (10) and a translator (20), one of said stator and said translator comprising a periodic magnet structure (13-15) and the other of said stator and said translator comprising a plurality of energizable coils (21-24). The phase relationship between stator and translator of the planar motor is determined by: energizing a plurality of said energizable coils in turn with an oscillating signal sufficient to cause vibrations of said translator having an amplitude less than the period of said periodic magnet structure; measuring said vibrations of said translator; and determining the phase relationship between said translator and said stator on the basis of said measured vibrations. Alternatively, the relationship between stator and translator is be determined by detecting means detecting distinct optical marks on the periodic magnet array. Control means determine the relationship between said translator and said stator on the basis of detected distinct optical marks

Positioning system and lithographic projection apparatus

A lithographic apparatus has a positioning system for positioning an object table, said positioning system comprising a planar motor having a stator (10) and a translator (20), one of said stator and said translator comprising a periodic magnet structure (13-15) and the other of said stator and said translator comprising a plurality of energizable coils (21-24). The phase relationship between stator and translator of the planar motor is determined by: energizing a plurality of said energizable coils in turn with an oscillating signal sufficient to cause vibrations of said translator having an amplitude less than the period of said periodic magnet structure; measuring said vibrations of said translator; and determining the phase relationship between said translator and said stator on the basis of said measured vibrations. Alternatively, the relationship between stator and translator is be determined by detecting means detecting distinct optical marks on the periodic magnet array. Control means determine the relationship between said translator and said stator on the basis of detected distinct optical marks

Robotic Control for Vibration Reduction of Swinging Products

Input shaping can effectively reduce residual vibrations of flexible systems induced by the reference signal. For the control of cranes, the usefulness of input shaping is well known and implemented. A big knowledge gap is noted to apply input shaping to robotic pick and place. For these applications, the shaped reference trajectory could result in a reduced overall settling time. A frequency domain and time domain view is presented for this purpose. The main contribution of this paper is the introduction of a formal proposition to relate the relative overshoot to the ratio of vibration and acceleration time. This enables the selection of the highest possible acceleration value to meet the overshoot specification. An experimental validation, confirms the performance improvement obtained for a cheese product packed in a liquid bag suspended by a vacuum suction cup gripper for a delta robot system

State of the Climate in 2012

International audienceEditors note: For easy download the posted pdf of the State of the Climate for 2012 is a very low-resolution file. A high-resolution copy of the report is available by clicking here. Please be patient as it may take a few minutes for the high-resolution file to download