US 6,584,367 B1Granted

Stage position control method and stage position control apparatus capable of improving positioning precision

AssigneeSumitomo Heavy Industries, Ltd.

InventorsKenichi Makino, Yoshiyuki Tomita, Hidehiko Mori

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Abstract

A Y stage is capable of translational driving in the Y-axial direction, by independently controllable Y1 linear motor and Y2 linear motor. The amount of movement of the Y stage is detected by a Y1 linear encoder and Y2 linear encoder, and fed back to a Y control system and θ control system. The Y control system outputs a translational thrust command value, by receiving the average value of each positional detecting value measured by the Y1 linear encoder and Y2 linear encoder as the stage translational direction position feedback value. The θ control system receives the difference between each position detecting value as a stage yawing direction position feedback value, and outputs a yawing direction thrust command value. A non-interference block outputs Y1 linear motor thrust command value and Y2 linear motor thrust command value, by the use of the translational thrust command value and the thrust command value. Thus, the movement of the Y stage can be divided into translational direction movement and yawing direction movement, and independently controlled and compensated.

Claims7

Dependent claims

A stage position control method, applied to a stage device comprising a stage, a driving axis which mounts said stage and which is driven in one axial direction, and first and second driving units for performing translational driving of said driving axis independently at two positions, said method comprising the steps of detecting the amount of movement of said first and said second driving units by first and second position detecting units, respectively, and controlling said first and said second driving units with first and second feedback control systems, respectively;

wherein said first feedback control system outputs a translational thrust command value to said first and said second driving units, by receiving an average value of each position detecting value measured by said first and said second position detecting units as a position feedback value of the stage translational direction;
and wherein said second feedback control system divides the motion of said stage into translational direction motion and yawing direction motion, and independently performs controlling and compensating thereof, by receiving the difference between said each position detecting value as a position feedback value of the stage yawing direction, and by outputting a yawing direction thrust command value to said first and said second driving units.

A stage position control apparatus, applied to a stage device comprising a stage, a driving axis which mounts said stage and which is driven in one axial direction, and first and second driving units for performing translational driving of said driving axis independently at two positions, said stage position control apparatus detecting the amount of movement of said first and said second driving units by first and second position detecting units, respectively, and controlling said first and said second driving units with first and second feedback control systems, respectively, said stage position control apparatus comprising:

coordinate converting means for calculating an average value from each position detection value measured by said first and said second position detecting units and outputting the results to said first feedback control system as a position feedback value of the stage translational direction, and also calculating a difference between said each position detection value and outputting the result to said second feedback control system as a position feedback value of the stage yawing direction;
wherein said first feedback control system comprises:
a first subtracter for calculating a difference between said stage translational direction position command value and said stage translational direction position feedback value;
a first PID compensator which receives the difference calculated at said first subtracter as an input thereof and outputs a thrust target value;
a disturbance observer which computes estimated disturbance for the stage, based on said translational thrust command value calculated from said thrust target value and on said stage translational direction position feedback value;
and
a second subtracter for calculating a new translational thrust command value by subtracting said thrust target value from said estimated disturbance for the stage, and outputting the new translational thrust command value to said first and said second driving units;
and wherein said second feedback control system comprises:
a third subtracter for calculating a difference between said stage yawing direction command value and said stage yawing direction position feedback value;
and
a second PID compensator which receives the difference calculated at said third subtracter as an input thereof and outputs a yawing direction thrust command value to said first and said second driving units.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/608,068Filed 30 Jun 2000
Priority: JP 11-1893362 Jul 1999
Granted: 24 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G05B 19/195
Characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement…:…
G05B 2219/41195
Servomotor, servo controller till figures: cross coupled feedback, position change one axis effects control of other
G05B 2219/41368
Servomotor, servo controller till figures: disturbance observer, inject disturbance, adapt controller to resulting effect
G05B 2219/42033
Servomotor, servo controller kind till VSS: kind of servo controller