JP2002049425A - Method for controlling stage and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of a tool or the like resulted from the stop of a stage or the change of the attitude of the stage due to the generation of the error of position detection. SOLUTION: A movable position is measured by two laser measuring machines with different places on an X stage 1 as observation points, and a straight advance position is measured from the measured mean value of the both measuring machines, and a revolution attitude is measured and controlled from the difference. Also, a normal time gain to be controlled by using the both measuring machines and a straight advance abnormal time gain in the case that one measuring machines is turned into an abnormal state are preliminarily stored in a memory 1 for string a gain, and a revolution thrust command and difference data calculated by subtracting the present target position from the position detected by each measuring machine are stored in a memory 14 for a correction data base so as to be made correspond to a straight advance target position applied to a DSP 12. when one of the measuring machines is turned into an abnormal state, the control is performed by using the abnormal time gain extracted from the memory 13, and the revolution thrust command and the difference data of each measuring machine are read according to the target position, and added to a feedback signal or a thrust command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage control method and a control device for a processing apparatus or the like.

[0002]

2. Description of the Related Art In positioning control of a moving stage mechanism for precise positioning, a mechanism using a laser length measuring device is often used as a control position and attitude measuring mechanism. However, in a laser length measuring device, there is a case where laser measurement is impossible due to a cause such as deterioration of a laser transmitter or a laser abnormality caused by blocking of a laser beam.

[0003] Conventionally, when an abnormality has occurred in a laser length measuring device, the control device cuts off the driving force or switches the driving motor to a regenerative mode to prevent the stage from running out of control using a mechanical brake. Take the way.

FIG. 8 is an example of a flowchart showing a conventional method of controlling a movable stage. In this figure, “preparation processing start” in step 601 indicates the start of processing performed before the stage is moved and processing is performed. In step 602, the position and yawing control gain are determined using both the two lasers 1 and 2.

[0005] "End of preparation processing" in step 603 is the end of preparation processing before machining. “Control routine start” in step 604 indicates the start of processing at each sampling interval when the stage is moved by the processing operation. “Sampling time?” Of step 605 is a process of checking whether the sampling time for performing the control processing in the DSP serving as the control arithmetic unit and waiting for the sampling time.

[0006] In step 606, "Receiving the linear target value of the target position in the straight direction and the rotational target value of the rotational direction target value as the current target value" means that the linear target value which is the target value in the linear direction for each sampling interval is set. This is a process of receiving a rotation target value, which is a target value in the rotation direction, from a higher-order arithmetic device of the control device.

[0007] In step 607, "Is laser 1 and laser 2 normal?" Means that the position of the stage in the linear direction and the attitude in the rotational direction of the stage are detected by two laser measuring instruments. This is a process of determining whether or not an error such as interference of one of the lasers has occurred.

[0008] "Measurement of position data 1 and 2 of lasers 1 and 2" in step 608 is a process selected in step 607 when both lasers 1 and 2 which are position detectors are normal. Since the two lasers 1 and 2 serving as the position detectors are normal, the current position is simultaneously measured from both of the position detectors. The position data measured by the laser 1 and the laser 2 is referred to as position data 1 and position data 2.

In step 609, "position data 1 and 2 are used as feedback signals, control calculations are performed using the normal gain with the current straight-ahead target value and rotation target value, and LM1
In the calculation of the thrust commands 1 and 2 of "1 and 2", the position data 1 and the position data 2 are controlled as feedback signals by using a control operation formula using the laser 1 and the laser 2 which are normal gains as a detection system and their coefficient data. Perform the operation. The target value at this time is read in step 606, and the thrust command 1 and the thrust command 2 for the linear motors LM1 and LM2 are calculated by control calculation.

In step 610, "the calculated thrust command is set to L
In the case of “outputting to M1 and M2 and controlling the position in the straight direction and the attitude in the rotation direction”, a thrust command is given to the linear motor LM current amplifier, and thrust is generated by the linear motors LM1 and LM2. The thrust command is for controlling the stage to target values in the straight-ahead direction and the rotation direction, and thereby controls the positioning of the stage.

"Stop control?" In step 611 is a judgment as to whether or not to end the control. If the process is not to be stopped, the process returns to step 605. If the process is to be ended, the process is terminated by "end of process routine" in step 612. finish.

[0012] "Transition to emergency stop routine" in step 613 is the result of checking and judging in step 607.
This processing is performed when an error has occurred in both the laser 1 and the laser 2. In this case, since it is impossible to continue the control, for example, the control is stopped separately and the stage is held by a mechanical brake. To an emergency stop routine.

As described above, in particular, the position of the stage in the rectilinear direction is measured using the two laser optical axes, and the movement of the two axes in the rectilinear direction and the rotational direction is detected and controlled from the average value and the difference. In such a case, the stage has a detector, and the guide part is constrained so as to be movable in one axis direction by a guide using an air bearing, and is supported with a strong spring constant against movement in the other direction. The stage mechanism controls the rotation direction about the axis orthogonal to the direction in which the laser beam moves straight. The control of the two axes is stopped, and a mechanical brake or the like is used to forcibly stop the control on the spot.

[0014]

However, in the above conventional example, when a laser abnormality occurs, the control is stopped, and
In order to forcibly stop the stage, for example, when the control is stopped during cutting with a precision cutting device, the stage moves in an unintended direction. Due to this control suspension, if the moving direction is the direction in which the machining tool cuts the work surface, there is a danger that the work tool will cut more than the setting in the work piece, and the work piece will be damaged or the worst machining tool will be damaged. there were.

In order to prevent such a situation, there is a method of using a laser length measuring device having an axis larger than the axis to be controlled as a backup when an error occurs. It is not realistic to install it on a shaft.

According to the present invention, even when one of the plurality of position detectors becomes undetectable, the position in the straight direction can be determined by using another position detector without emergency stop. A stage control method and control that can continuously control a stage to a safe place without changing a posture and without damaging a tool or a workpiece due to a stop of the stage or a change in posture when an error of a position detector occurs. It is intended to provide a device.

[0017]

In order to achieve the above object, a first stage control method according to the present invention is a method for controlling a movable stage to detect a moving amount of the stage in a straight traveling direction. A stage control method using a position detector, a drive mechanism for driving the stage, and a control device for controlling the drive mechanism based on an output of the position detector, wherein the plurality of position detectors And a gain storing step of storing a gain for performing control of the stage in the straight traveling direction using an output of another position detector without using at least one of the above.

The plurality of position detectors detect a position in the straight traveling direction with reference to a plurality of locations on the stage which are constrained and supported by guide means and move integrally in the straight traveling direction,
The average value of the plurality of position data detected at the same time may be detected as a moving amount in the straight traveling direction, and the moving amount of the stage in the rotating direction of the stage may be detected based on a difference between the plurality of position data detected at the same time. The drive mechanism may be characterized in that the stage can be driven in a direction of rotation and a rotation that can be detected by the plurality of position detectors, and the control device may be configured to detect the position of the straight ahead and the number of position detectors. The position in the rotation direction may be controlled via the driving mechanism.

In the gain storage step, all of the plurality of position detectors are used as a calculation formula of a control calculation performed by the control device and a gain as a coefficient thereof, and a normal direction and a rotation direction are optimally controlled. Time gain, and a number of anomalies commensurate with the number of all position detectors used to optimally control the position in the straight-ahead direction without using any one of the plurality of position detectors It is desirable to store the time gain.

Further, the control method according to the present invention is characterized in that each position detection is obtained by subtracting a target position from position data, which is a detection value of a position detector at each target position at a predetermined interval in a straight-forward direction provided to the drive mechanism control device. A database storing step of storing difference data of the position of each device and a thrust command value in the rotation direction for the drive mechanism, and when all of the position detectors can perform normal position detection, Using a gain, the straight-line direction and the rotational direction position detected by all of the position detectors are used as feedback signals, and the straight-line thrust command value and the rotational direction thrust command value for the drive mechanism are transmitted to the drive mechanism by the drive mechanism control device. Is calculated to control the position and orientation, and if any of the plurality of position detectors becomes abnormal and the position cannot be detected, Out of the data for each target position at regular intervals stored in the database storage step, the data is stored at the target position closest to the current target position, and is compared with the target value in the linear direction of all the position detectors that have not caused any abnormality. The difference data as the difference and the thrust command value to the drive mechanism in the rotation direction are read from the data stored in the database storage step, and the thrust command value read from the database storage step as the thrust command value in the rotation direction of the drive mechanism. , And the current position in the straight direction is detected by the position
As a feedback signal, a value obtained by subtracting the average value of difference data other than the position detector having an abnormality from the current position is used as a feedback signal, and the abnormality-time gain capable of optimally controlling the straight ahead direction with a position detector having no abnormality is used. The control may be performed by performing a control calculation in the drive mechanism control device and giving a thrust command in the straight traveling direction to the drive mechanism.

A second stage control method according to the present invention comprises:
A two-axis stage having an X stage and a Y stage is controlled, and a plurality of X direction position detectors for detecting the amount of movement of the X stage in the X direction and a plurality of positions for detecting the amount of movement of the Y stage in the Y direction. A Y-direction position detector, an X-direction drive mechanism for driving the X-stage, a Y-direction drive mechanism for driving the Y-stage, and an output from the X-direction position detector and the Y-direction position detector. A stage control method using an X-direction drive mechanism and a control device for controlling a Y-direction drive mechanism, wherein at least one of the plurality of X-direction position detectors is not used and an output of another X-direction position detector is used. And a gain storing step of storing a gain for controlling the X-stage in the straight traveling direction by using

The X stage is restrained and supported by the Y stage by guide means, and the plurality of X-direction position detectors detect a plurality of positions by using a plurality of positions of the X stage as reference points and detect the plurality of positions simultaneously. An average value of the plurality of position data may be set as a movement amount in the straight traveling direction, and a difference between the plurality of position data detected at the same time may be detected as a movement amount of the X stage in the rotation direction.

[0023] The Y-direction position detector may be characterized in that the Y-direction position detector detects a position in the Y-direction by using, as a reference point, a position of the Y-stage that moves along the X-axis in a straight-moving direction as a movable direction. The X-direction drive mechanism includes:
The X stage may be driven in the X-direction straight-ahead and rotation directions detectable by the plurality of X-direction position detectors, and the Y-direction drive mechanism may be detectable by the Y-direction position detector. In the Y direction,
It may be characterized in that the stage can be driven.

In the gain storage step, all of the X-direction position detectors are used as a gain, which is a calculation formula of a control calculation in the X-direction performed by the control device and a coefficient thereof, and the straight-moving direction and the rotation direction in the X-direction are used. Normal gain for optimal control,
And all of the X-direction position detectors used to optimally control the position in the X-direction in the X-direction without using any one of the X-direction position detectors among the plurality of X-direction position detectors It is preferable to store a number of emergency abnormal gains corresponding to the number, and it is preferable to include a gain switching step of switching the gain stored in the gain storage step.

Further, the control method according to the present invention is characterized in that, for each target position at a predetermined interval in the X and Y directions in the rectilinear direction given to the drive mechanism control device, the position data which is a detection value of the X direction position detector is obtained. A database storing step of storing position difference data for each X-direction position detector obtained by subtracting the X-direction straight-ahead target position and a thrust command value in the rotation direction for the X-direction drive mechanism, wherein all position detectors When the position can be normally detected, the normal gain is used, and the positions in the straight-ahead direction and the rotation direction in the X direction detected by all the position detectors are used as feedback signals in the drive mechanism control device. A thrust command value in the straight-moving direction and a thrust command value in the rotation direction to the X-direction drive mechanism are calculated to control the position and orientation, and any one of the plurality of X-direction position detectors is used. If the position detector becomes abnormal and the position cannot be detected, one of the data for each of the target positions in the X and Y directions at regular intervals stored in the database storage step is regarded as the current target position. Difference data, which is stored at the nearest target position and is the difference between the target value in the X direction of all the X direction position detectors in which no abnormality has occurred and the thrust command value to the drive mechanism in the rotation direction, is stored in the database. A thrust command value read from the data stored in the database storage step is read from the data stored in the storage step, and a thrust command value read from the data stored in the database storage step is given as a thrust command value in the rotational direction of the X-direction drive mechanism. Detects the current position in the straight-ahead direction and subtracts the average value of the difference data from the current position in the X direction other than the position detector that caused the abnormality as a feedback signal. Using the abnormal time gain in which the X-direction position detector having no abnormality can optimally control the straight-moving direction, the drive mechanism control device performs control calculation, and the thrust to the X-direction driving mechanism in the straight-moving direction. The control may be performed by giving a command.

The first stage control device according to the present invention comprises:
A movable stage, a plurality of position detectors for detecting the amount of movement of the stage in the straight direction, a drive mechanism for driving the stage, and a drive for controlling the drive mechanism based on the output of the position detector A mechanism controller and a gain storage memory for storing a gain for controlling the stage in the rectilinear direction by using an output of another position detector without using at least one of the plurality of position detectors And characterized in that:

[0027] The plurality of position detectors detect positions in the rectilinear direction with reference to a plurality of points on the stage which are constrained and supported by guide means and move integrally in the rectilinear direction.
The method may further comprise detecting an average value of the plurality of position data detected at the same time as a moving amount in the straight traveling direction, and detecting a moving amount in the rotation direction of the stage based on a difference between the plurality of position data detected at the same time. The mechanism may be capable of driving the stage in a straight-ahead and rotational direction that can be detected by the plurality of position detectors.

The gain storage memory controls the calculation formula of the control operation performed by the drive mechanism control device and the gain, which is a coefficient, by using all of the plurality of position detectors to optimally control the straight traveling direction and the rotation direction. Normal gain, and a number corresponding to the number of all position detectors used to optimally control the position in the straight-ahead direction without using any one of the plurality of position detectors. It is desirable to store the following abnormal gains.

Further, the control device according to the present invention may be configured such that each position detection value obtained by subtracting a target position from position data, which is a detection value of a position detector at each target position at a predetermined interval in a straight-ahead direction, provided to the drive mechanism control device. A database storage memory for storing difference data of the position of each device and a thrust command value in the rotation direction for the drive mechanism, and when all of the position detectors can perform normal position detection, Using a gain, the straight-line direction and the rotational direction position detected by all of the position detectors are used as feedback signals, and the straight-line thrust command value and the rotational direction thrust command value for the drive mechanism are transmitted to the drive mechanism by the drive mechanism control device. Is calculated and the position and orientation are controlled, and if any of the plurality of position detectors becomes abnormal and the position cannot be detected, Of the data for each target position at regular intervals stored in the database storage memory, the data stored at the target position closest to the current target position and the target value in the straight direction of all the position detectors that are not abnormal The difference data as the difference and the thrust command value to the drive mechanism in the rotation direction are read from the database storage memory, and the thrust command value read from the database storage memory as the thrust command value in the rotation direction of the drive mechanism is given. The current position in the straight traveling direction is detected by the position detector that does not cause the abnormality, and a value obtained by subtracting the average value of the difference data from the current position other than the abnormal position detector as a feedback signal is not abnormal. Using the abnormal time gain that can be optimally controlled in the straight-ahead direction by the position detector, performs a control calculation in the drive mechanism control device, It may be characterized by performing control by providing a thrust command in the straight direction to the serial drive mechanism.

[0030] The stage control device according to the second aspect of the present invention comprises:
A two-axis stage having an X stage and a Y stage is controlled, and a plurality of X direction position detectors for detecting the amount of movement of the X stage in the X direction and a plurality of positions for detecting the amount of movement of the Y stage in the Y direction. A Y-direction position detector, an X-direction drive mechanism for driving the X-stage, a Y-direction drive mechanism for driving the Y-stage, and an output from the X-direction position detector and the Y-direction position detector. A drive mechanism control device for controlling the X-direction drive mechanism and the Y-direction drive mechanism, and at least one of the plurality of X-direction position detectors without using at least one of the plurality of X-direction position detectors.
A gain storage memory for storing a gain for controlling the X-stage in the straight traveling direction using the output of the direction position detector.

The X stage is restrained and supported by the Y stage by guide means, and the plurality of X-direction position detectors detect a plurality of positions by using a plurality of positions of the X stage as reference points and detect the plurality of positions simultaneously. The average value of the plurality of position data may be set as the moving amount in the straight traveling direction, and the difference between the plurality of position data detected at the same time may be detected as the moving amount in the rotation direction of the X stage. The apparatus may be characterized in that the position of the Y stage that moves together with the X stage in the direction of movement in the Y-axis direction as a movable direction is detected as a reference point in the Y direction.

The X-direction driving mechanism may be characterized in that the X-stage can be driven in the X-direction linear and rotational directions detectable by the plurality of X-direction position detectors. The Y stage may be driven in a Y-direction straight traveling direction that can be detected by the Y-direction position detector.

The gain storage memory uses all of the X-direction position detectors as a calculation formula of a control calculation in the X-direction performed by the drive mechanism control device and a gain which is a coefficient thereof. In order to optimally control the normal direction gain that optimally controls the rotation direction, and to optimally control the position in the X-direction linear direction without using any one of the X-direction position detectors among the plurality of X-direction position detectors. It is desirable to store as many abnormal gains as the number of all the position detectors to be used, and it is preferable to include a gain switching means for switching the gain stored in the gain storage memory.

Further, the control device according to the present invention is characterized in that, for each target position at predetermined intervals in the X- and Y-directions in the rectilinear direction given to the drive mechanism control device, the position data which is the detection value of the X-direction position detector is obtained. A database storage memory for storing position difference data for each X-direction position detector obtained by subtracting the X-direction straight-ahead target position and a thrust command value in the rotation direction for the X-direction drive mechanism; Can normally detect the position, the normal-time gain is used, and the drive mechanism in the X-direction linear and rotational directions detected by all the X-direction position detectors is used as a feedback signal. The control device calculates the thrust command value in the rectilinear direction and the thrust command value in the rotation direction to the X-direction drive mechanism to control the position and orientation, and among the plurality of X-direction position detectors, If any of the X-direction position detectors becomes abnormal and the position cannot be detected, the current position data of the target position in the X and Y directions at regular intervals stored in the database storage memory is used. Is stored at the target position closest to the target position of all X
The difference data, which is the difference between the directional position detector and the target value in the X-direction linear direction, and the thrust command value to the drive mechanism in the rotation direction are read from the database storage memory, and the thrust command in the rotation direction of the X-direction drive mechanism is read. A thrust command value read from the database storage memory is given as a value, and the X-direction position detector in which no abnormality has occurred detects the current position in the straight traveling direction. The value obtained by subtracting the average value of the difference data is used as a feedback signal, and the abnormal-time gain, which enables optimal control in the straight-ahead direction by the X-direction position detector in which no abnormality has occurred, is used for control calculation in the drive mechanism control device. The control may be performed by giving a thrust command in the straight traveling direction to the X-direction drive mechanism that has not caused an abnormality.

In the above stage control method or control device, when all the position detectors are in a normal state, a target position is given to the drive mechanism control device, and when the stage is moved, the target position is set for each target position. It is desirable to constantly update the data stored in the database storage step or the database storage memory, and the driving mechanism is a plurality of linear motors, and the thrust in the straight traveling direction is given by the sum of the thrusts of the plurality of linear motors. Preferably, the thrust in the rotating direction is given by the difference between the thrusts of some linear motors among the plurality of linear motors, and the guide means is preferably an air bearing.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a guide supporting a stage is freely supported in a direction of linear movement which is a movable direction and a guide supporting a stage in a rotational direction with a strong spring constant. In the stage, the position in the movable direction is measured by using different locations on the stage that move integrally with multiple laser length measuring devices as observation points, and the moving direction is determined by the average value of the position data of the multiple length measuring devices detected at the same time. The stage configuration measures the position in the rectilinear direction, and measures and controls the attitude in the rotational direction based on the difference between the position data of the plurality of length measuring devices detected at the same time. In a stage having such a configuration, a control gain for controlling using all the position detectors, and a case where any one of the plurality of position detectors is in an undetectable abnormal state. The control gain in the straight traveling direction is stored in the storage memory in advance. Further, the difference data obtained by subtracting the current target position from the rotational direction thrust command and the position detected by each position detector in relation to the target position in the straight traveling direction given to the drive mechanism control device is stored as a database, and a plurality of positions are stored. When one of the detectors becomes abnormal, the gain at the time of abnormality is taken out from the storage memory and control is performed with this gain.In addition, the thrust command in the rotational direction and the difference between each position detector and the target position are adjusted. By reading the data and adding it to the feedback signal or the thrust command, it is possible to prevent the stage control from being stopped due to an abnormality of one of the plurality of position detectors. .

By adopting a control method employing such a method, the control is not interrupted by an error of any one of the plurality of position detectors. In the case of rough machining in which deceleration stop is performed while controlling at the same position and attitude as described above, or rough machining which may slightly deteriorate accuracy, machining can be continued as it is. Therefore, it is possible to stop the control even if the laser causes an error in a state where the processing tool is in contact with the processing tool at the time of processing, and prevent the processing tool and the workpiece from being damaged by moving the stage due to the control stop. .

Further, by continuously updating the difference data and the data of the thrust command value in the rotating direction during machining, the influence of the error component of the guide changing over a long period of time, such as thermal deformation of the apparatus, can be minimized. It is possible to hold down.

In the present invention, the X-axis and X-axis
The stage is supported by the Y-axis stage by a guide means for restraining the other rotation and translational movements with a strong spring constant with the one-axis straight-moving direction as a movable direction, and moves integrally in the X-directional straightening direction. Using two or more different locations on the stage surface as observation points, detecting the position in the straight direction with a plurality of position detectors, and using the average value of the position data of the plurality of position detectors detected simultaneously as the amount of movement in the straight direction, A plurality of Xs detected as a movement amount in the rotation direction of the stage based on a difference between position data of a plurality of position detectors detected at the same time.
The present invention is also applicable to a case where a direction position detector is provided.

As described above, the X mounted on the Y stage
In the stage, the influence of the accuracy of the guide of the Y stage is superimposed on the data in the rotation direction. Therefore, in the control of the X stage of the XY stage, the database of the stage is stored not only in the X direction but also in association with the target position in the Y direction. This can deal with the XY stage.

[0041]

FIG. 1 is a block diagram of a stage control device according to a first embodiment of the present invention. In FIG. 1, an X stage 1 which is a movable stage is supported by a guide 2 using an air bearing. The movable direction 5 of the X stage 1 supported by the guide 2 is the X direction 16
The X stage 1 is movable in this direction. The support by the air bearing is to create a high pressure air layer between the movable part and the fixed part, and the movable direction is free to move because the movable part slides on the air layer,
Except for the movable direction, it is equivalent to being supported by a spring having a high spring constant until the movable part and the fixed part come into contact with each other.

The linear motor 1 (LM1) has a movable magnet 3
a linear motor 2 (LM2) includes a movable magnet unit 3b and a fixed coil unit 4b. The movable magnet portions 3a and 3b of the two linear motors LM1 and LM2 are fixed to the X stage 1, and by passing a current through the fixed coil portions 4a and 4b, positive and negative thrusts are generated in the movable direction along the X direction 5, respectively. generate. The force by which the movable magnet portion 3a of the LM1 and the movable magnet 3b of the LM2 push the X stage 1 is moved in the linear direction of the movable direction 5 by the average value of the generated thrusts, and the X guide is moved in the yawing direction 6 by the difference between the thrusts. The second air bearing can rotate within the range of the gap between the movable part and the fixed part.

The reflection mirrors 7a and 7b are connected to the X stage 1
Is attached to the linear motor via movable magnet portions 3a and 3b of the linear motor, and passes through the laser optical axes 9a and 9b between the laser interferometers 8a and 8b, so that the average length of the laser optical axes 9a and 9b is X. The amount of movement of the stage 1 in the linear direction of the movable direction 5 is measured, and the difference is used to measure the amount of rotation of the X stage 1 in the yawing direction 6.

The signals measured by the laser interferometers 8a and 8b are converted into distance data by the laser length measuring device position counters 10a and 10b, and the control calculation means in the control device 11 enclosed by a broken line in FIG. Is detected by the DSP 12 as a feedback signal for control. Further, the laser length measuring device position counters 10a and 10b determine whether the laser light detected by the laser interferometers 8a and 8b gives normal data that interferes normally or is in an error (abnormal) state. The signal is transmitted to the DSP 12. The DSP 12 detects the amount of movement of the X stage 1 in the movable direction 5 and the attitude in the yawing direction 6 from the change in the length of the laser optical axes 9a and 9b.

The control device 11 for controlling the driving mechanism includes DS
It has two storage memories, a gain storage memory 13 connected to P12 and a correction database memory 14 which is a database storage means. DSP12
Switches the control gain stored in the gain storage memory 13 by determining whether the laser is normal or not, and calculates a thrust command to LM1 and LM2 using an arithmetic expression and a coefficient that are the selected control gain, Command.

The correction database memory 14 stores the difference between the thrust command values to the LM1 and LM2 in relation to the target positions in the straight direction at regular intervals (for example, 1 mm) of the X stage 1 and the laser and laser 2 in the straight direction. The value subtracted from the target value is stored. The current amplifiers 15a and 15b of LM1 and LM2 receive the thrust command from the DSP 12, and change the thrust of LM1 and LM2 by increasing or decreasing the current value.

FIGS. 2 and 3 are flowcharts showing a stage control method according to the first embodiment of the present invention.
“Preparation processing start” in step 201 indicates the start of processing performed before moving the stage and performing processing.

Step 202 "determination of position and yawing control gain using both lasers 1 and 2"
The control calculation formula and its coefficient, which are the control gains of the position and orientation using all the laser length measuring devices used in the control of the laser length measuring device as the two position detecting means, are determined, and the gain of this embodiment is determined. This is a process of storing in the storage memory 13.

In step 203, "determination of position control gain using only laser 1" is performed by using only laser 1 without using laser 2 of the two laser length measuring devices in the straight-ahead direction. This is a process of determining a control gain for performing only the control gain and storing the control gain in the gain storage memory 13.

The "determination of position control gain using only laser 2" in step 204 is the reverse of step 202, in which a control gain for performing only control in the straight traveling direction using only laser 2 is determined. This is processing to be stored in the memory 13.

Step 205: “Constant interval of target position △
"X = 1 rotation direction target value determination" is to determine the interval between the target positions in the rectilinear direction stored in the correction database memory 14 to be 1 mm and determine the target position in the rotation direction for each target position. When moving in the movable direction along the guide 2, a target value is set to prevent the X stage 1 from slightly rotating due to bending of the guide 2. The target value in the rotation direction is determined and determined at a position at regular intervals in the linear direction so that the X stage 1 is not inclined in the yawing direction as much as possible within a range in which the thrust of the LM is not inferior to the rigidity of the guide 2.

In step 206, "set the target position at a constant interval.
Move the stage with normal gain by changing to X = 1mm increments. The “stage control to target values in the straight-ahead direction and the rotation direction by the control device” is a state in which the control of the X stage 1 is controlled using a control gain that all the control position detectors control in a normal state. The X stage 1 is moved by changing the target value in the straight traveling direction of No. 1. The target value in the straight traveling direction is set at intervals of △ X = 1 mm, which is a constant interval, and the target position in the rotation direction is also given at this time.
Control is performed to move the stage 1 to a target position in a target posture.

In step 207, "the DC component of the thrust command value of the difference between LM1 and LM2 at regular intervals is stored in the storage memory as the difference thrust command value", the control is performed at the target position in the direction of movement. During the control, the control is always performed while calculating the thrust command values to LM1 and LM2. The difference between the thrust command values to LM1 and LM2 is passed through a low-pass filter or the like to calculate a value close to the DC component of the command value. Then, the thrust command value is stored in the correction database memory 14 in association with the current target position in the straight traveling direction.

In step 208, “Laser 1 at regular intervals”
And 2 are calculated, and after subtracting the target position in the rectilinear direction, and stored in the storage memory as difference data, a control error occurs during control. The position data detected in step (1) is obtained by filtering the fluctuating position data with a low-pass filter or the like and calculating a value close to the DC component. Difference data is calculated by subtracting the current target value in the straight traveling direction from the calculated DC component. The difference data between the laser 1 and the laser 2 is stored in the correction database memory 14 in association with the current target position in the straight traveling direction.

In step 209, "Is all moving within the effective stroke in the straight-ahead direction at regular intervals and storing data?", The X stage 1 is moved at regular intervals within the effective range. Steps 208 to 207 are performed to determine whether all the processes have been completed. The X stage 1 is moved at regular intervals of 一定 X = 1 mm until the effective range is completed, and steps 205 to 207 are completed. Do until.

"End of preparation processing" in step 210 is the end of preparation processing before processing. “Control routine start” in step 211 indicates the start of processing at each sampling interval when the X stage 1 is moved by the processing operation. “Sampling time?” Of step 212 is a process of checking whether or not the sampling time for performing the control processing in the DSP 12 as the control arithmetic unit and waiting for the sampling time.

"Receiving the linear target value of the target position in the rectilinear direction and the rotational target value of the rotational direction target value as the current target value" in step 213 is the linear target value which is the linear target value for each sampling interval and the rotation. This is a process of receiving a rotation target value, which is a target value in the direction, from a higher-order arithmetic device of the control device.

In the step 214, "Is laser 1 and laser 2 normal?", As shown in FIG. 1, which is the first embodiment of the present invention, the two laser length measuring devices are used in the linear direction of the X stage 1. Although the position and orientation in the rotation direction are detected, this laser 2
This is a process of judging whether or not an error such as interference of one of the lasers in the book has occurred.

"Measurement of position data 1 and 2 of lasers 1 and 2" in step 215 is a process selected in step 214 when both lasers 1 and 2 which are position detectors are normal. Since the lasers 1 and 2 as detectors, which are a plurality of position detecting means, are normal, the current position is measured simultaneously from both of the position detectors. Laser 1
The position data measured in steps 2 and 3 are referred to as position data 1 and 2.

In step 216, "the position data 1 and 2 are used as feedback signals, the current straight target value and the rotation target value are used as normal gains, control calculations are performed, and LM1
In the calculation of the thrust commands 1 and 2 of "1 and 2", the position data 1 and the position data 2 are controlled as feedback signals by using a control operation formula using the laser 1 and the laser 2 which are normal gains as a detection system and their coefficient data. Perform the operation. The target value at this time is the value read in step 213, and L
The thrust command 1 and the thrust command 2 for M1 and LM2 are calculated by control calculation.

In step 217, "the calculated thrust command is set to L
M1 and M2 to control the position in the straight direction and the attitude in the rotation direction ”.
A thrust command is given to 15b, and thrust is generated by LM1 and LM2. The thrust command is for controlling the X stage 1 to target values in the straight traveling direction and the rotating direction.
The positioning control of the stage 1 is performed.

In step 218 “calculating difference data obtained by subtracting the straight-ahead target value from position data 1 and 2 and extracting DC components with a low-pass filter”, position data 1 and position data 2 detected in step 214 are given in step 213. Subtract with the current straight ahead target value. The calculated difference data is filtered by a low-pass filter to calculate a value close to the DC component.

In step 219, “the thrust command 1—the thrust command 2 in the rotational direction is calculated, and D
In the “C component extraction”, the difference between the individual command thrust commands 1 and 2 for the linear motors LM1 and LM2 is calculated to calculate the thrust command value in the rotation direction. Further, this rotation direction thrust command is filtered by a low-pass filter to calculate a value close to the DC component.

In step 220, “target position ≧ current straight target value−ΔX / 2, target position <current straight target value−ΔX”
/ 2, the difference data and the DC component of the rotational direction thrust data are stored in the memory as the data of the target position of "/ 2, the target position at the interval of △ X = 1 mm closest to the current straight target value is calculated. In association with this, the difference data of the position calculated in steps 218 and 219 and the DC component of the thrust command value in the rotation direction are stored in the correction database memory 14.
To memorize.

"Stop control?" In step 221 is for judging whether or not to end the control. If the process is not to be stopped, the process returns to step 212. If the process is to be ended, the process is terminated by "end of process routine" in step 222. finish.

In step 223 “measurement of position data 1 of laser 1”, in step 214 “laser 1 and laser 2
Is normal? In the branching process of [1], only the laser 2 is abnormal, and the position data 1 as the position data of the laser 1 is measured in a state where the position data can be detected only by the laser 1.

Step 224: “N to N including the current straight-ahead target value and given by △ X * N [N is a natural number]
In “fetching the difference thrust command at the two target positions given by −1 or N + 1 and the difference data 1 of the position from the storage memory”, the linear target value given at step 213 is stored in the correction database memory 14. △
A search is made between the target position for each X and the next target position for each △ X, and the current straight target value is △ X * N
If the value of [N is a natural number], the data is read from the correction database memory 14 and the data of the two closest target positions with the current straight target value in between.

In step 225, “difference data 1 and difference thrust command taken out of the memory are stored in the target positions N and N
Calculating the difference data 1 and the difference thrust at the current target position by interpolating between −1 or N + 1 ”, if the current straight-ahead target value is a value of △ X * N [N is a natural number], step 22
4, the difference data 1 and the difference thrust command value read from the storage memory are used as they are. Fixed interval △ X
In the case of between the target positions, the differential data 1 and the differential thrust value are interpolated at the target positions at both ends, and the differential data 1 and the differential thrust command value at the current straight target value are calculated.

The “position data 1−difference data = current position, current position calculation” in step 226 is the same as step 2
Data obtained by subtracting the difference data 1 calculated in step 224 from the position data 1 read in 23 is calculated as the current position in the straight traveling direction. Since the position data 1 is not the current position as it is because the X stage 1 is tilted in the rotation direction, this is a process considering the influence of the rotation direction measured in advance.

In step 227, "position data 1-position difference data is used as a feedback signal, and control calculation is performed using the gain using only laser 1 with the current straight target value to calculate the total thrust command of LM1 and LM2. ”, The position is calculated by using the control operation formula, which is the gain of the position control in the straight ahead direction using only the laser 1 previously stored in the gain storage memory 13 at the current position calculated in the process of step 226, and the coefficient thereof. The control operation is performed by the control device 11, and the total thrust command value for LM1 and LM2 is calculated.

In step 228, “Total thrust command = LM1”
Thrust + LM2 thrust, difference thrust command = LM1 thrust-LM
"Calculate LM1 and LM2, which are 2 thrusts", in allocating the total thrust command values for LM1 and LM2 calculated in step 227 to LM1 and LM2,
The thrust commands to LM1 and LM2 are allocated so that a thrust difference is obtained by the difference thrust command calculated in step 5.

In step 229, "the calculated thrust command is set to L
In M1 and M2, the position is controlled and the rotation direction is balanced by the guide portion rigidity and the LM thrust. In the case of "the thrust to the LM1 and LM2 calculated in the process in step 228, respectively, the linear motors LM1 and LM2 travel straight. Control the position and orientation. The rotation direction is balanced by the difference thrust command given to LM1 and LM2 and the rigidity of the guide portion, and the position in the straight traveling direction is controlled without changing the posture in the rotation direction.

Steps 230 to 236 are the same as steps 223 to 228 except that laser 1 and laser 2 are interchanged. “Transition to emergency stop routine” in step 237 is a process in the case where an error has occurred in both laser 1 and laser 2 as a result of the check and determination in step 214. In this case, control is not continued. Because it is possible, for example, separately suspend control,
The routine shifts to an emergency stop routine in which the X stage 1 is held by a mechanical brake.

(Second Embodiment) The present invention is applied to an XY stage in which the guide supporting the X stage is a structural member of the Y stage, and the X stage moves in the Y direction when the Y stage moves in the Y direction. Is applied, the attitude of the X stage in the rotation direction is influenced by the guide of the Y stage. Therefore, when the Y guide that enables the Y stage to move in the Y direction is bent, a target value for correcting the attitude of the X stage in the rotation direction is given as data of each point on the XY plane.

Therefore, in the second embodiment, the difference data and the difference thrust command of the position measured in relation to only the target value in the straight ahead direction in the X direction are used in the first embodiment.
The difference data and the difference thrust command of the position measured in relation to the target values in the X and Y directions are used.

FIGS. 4 and 5 show flowcharts of control in the second embodiment of the present invention. In FIG. 4, FIG.
In the processing different from the above, in step 301, the mesh is cut at regular intervals △ X = 1 mm and △ Y = 1 mm in the XY plane, and the rotational direction target position for each point is determined. In steps 301 to 305, a database is created by moving the stage within the effective stroke of the XY plane every ΔX = 1 mm and ΔY = 1 mm.

In step 306 in FIG. 5, the method of updating the database of the target position is different from the method in step 219 in the first embodiment in that the method is related only to the straight ahead direction of X, and is related to the target values of X and Y in the straight ahead direction. Was.

In steps 307 and 309,
It is determined which current X and Y straight-ahead target values are included in the minimum mesh of △ X and ＸY obtained by dividing the XY plane into meshes, and differential data and differential thrust of four points at four corners of the mesh are determined. The command is read from the correction database memory 14.

In steps 308 and 310,
The difference data and the thrust command of the difference are interpolated from the current distance between the current target positions in the X and Y straight directions and the four corners of the target value mesh including the straight target values, and the current X and Y values are calculated. The differential data and the differential thrust command at the straight target value in the straight traveling direction are calculated. Other steps are the same as those in the first embodiment.

By performing the above processing, in the X stage moving on the XY plane, even if one of the plurality of position detectors becomes abnormal, the stage can be controlled without suddenly changing the posture. It is possible to move while moving.

FIG. 6 is a perspective view showing an example of an XY stage mechanism to which the present invention is applied. In FIG. 6, an X stage 401 is a stage movable portion of a stage moving mechanism,
The stage 401 is moved up and down by an air bearing (not shown) with respect to the XY guide 404 so that friction does not occur when moving on the XY plane represented by the X-axis direction 419 and the Y-axis direction 420. Supported in the direction. Further X
The stage 401 is supported by an air bearing (not shown) with respect to the X stage guide 403 of the Y stage 402, and moves on the Y stage 402 in the X-axis direction 41.
9 can be moved in the driving direction. For movements other than in the X-axis direction, the air bearing is supported by an air layer (several micrometers) between the movable part and the guide surface of the fixed part. If it is within the range of changing the gap of several micrometers that does not touch, it is equivalent to supporting through a very strong spring. Movement within a few micrometers) is possible.

The driving mechanism, which is the driving means of the X stage 401, includes the X linear motor movable magnet portions 406a and 406b.
And an X linear motor fixed coil unit 407a and 407b. The X linear motor movable magnets 406a and 406b are positioned on the line passing through the center of gravity of the X stage 401 and at an equal distance from the center of gravity of the X stage 40.
1 is fixed so as to be pushed, and the X linear motor fixed coil section 4
07a and 407b are fixed to the Y stage 402, and the combination of the X linear motor movable magnet section 406a and the X linear motor fixed coil section 407a and the X linear motor movable magnet section 4 are fixed.
06b and the X linear motor fixed coil portion 407b can each provide a driving force in the X-axis direction of the X stage 401, so that the two linear motors push the center of gravity of the X stage 401. . Further, by changing the distribution of the thrust, a force in the rotation direction about the Z axis 421 around the center of gravity of the X stage 401 can be applied.
The gap between the stage 402 and the air bearing that supports the X stage 401 is changed so that the X stage 401 can be rotated around the Z axis 421 within a small range (about micro radians).

The control position detector is composed of X stage reflection mirrors 410a and 410b and X interferometers 414a and 414
b, X-stage reflecting mirrors 410a, 41
0b and the corresponding X interferometers 414a and 414b pass the X laser optical axes 415a and 415b, which are the laser beams for length measurement, respectively, and shift the distance between the reflection mirrors 410a and 410b and the interferometers 414a and 414b. Is a laser length measuring device that measures the position of the X stage 401 by measuring. The X laser beam axis 415a is parallel to the direction of the X axis 419, and the Y stage 40 on which the X interferometer 414a is mounted.
The change in the distance to the X-stage reflection mirror 410a is measured based on the reference number 2. The X laser beam axis 415b is also parallel to the direction of the X axis 419, and measures the change in distance to the X reflection mirror 410b with reference to the Y stage 402 on which the X interferometer 414b is mounted. X stage reflection mirrors 410a and 410
Assuming that a line segment connects points reflecting the X laser optical axes 415a and 415b, b is a line segment passing through the center of gravity of the X stage movable portion, and is arranged so as to be bisected by the center of gravity. By arranging in this manner, changes in the respective positions between the X-stage reflecting mirror 410a and the X interferometer 414a and between the X-stage reflecting mirror 410b and the X interferometer 414b are detected. The X stage 401 is arranged so that the amount of movement of the center of gravity of the X stage 401 in the direction of the X axis 419 and the rotation of the X stage 401 about the Z axis 421 can be measured.

The driving mechanism which is the driving means of the Y stage 402 includes Y linear motor movable magnet portions 408a and 408b.
And Y linear motor fixed coil portions 409a and 409b
And a linear motor composed of The Y linear motor fixed coil portions 409a and 409b
a and 405b, and the Y linear motor movable magnet section 4
08a and the combination of the Y linear motor fixed coil portion 409a and the combination of the Y linear motor movable magnet portion 408b and the Y linear motor fixed coil portion 409b can respectively provide a driving force in the Y axis direction of the Y stage 402. It is. Further, by changing the distribution of the thrust, a force in the rotation direction around the Z axis 421 around the center of gravity of the Y stage 402 can be applied, and the gap between the air bearings supporting the Y stage 402 from the Y guides 405a and 405b can be changed. Then, a small range (about micro radians), Y
The stage 402 is arranged so as to be able to rotate around the Z axis 421.

The control position detector comprises a Y stage reflection mirror 411, a reflection mirror (not shown) hidden by the Y linear motor movable magnet section 408a, and Y interferometers 416a and 416b.
X laser optical axes 417a and 417b, which are laser beams for length measurement, are passed between the Y-interferometers 416a and 416b.
This is a laser length measuring device that measures the position of the Y stage 402 by measuring the amount of change in the distance between the reflection mirror and the interferometer. Y laser optical axis 417a is parallel to the direction of Y axis 420 and measures the change in distance from Y interferometer 416a to the corresponding Y stage reflecting mirror. The Y laser optical axis 417b is also parallel to the Y axis 420 direction and measures a change in the distance from the Y interferometer 416b to the reflection mirror 411. By arranging in this manner, the space between the Y-stage reflection mirror and the Y interferometer is detected, and the Y-axis
The movement amount in the zero direction and the rotation of the Y stage 402 about the Z axis 421 can be measured.

With the above configuration, the X-stage reflection mirrors 410a and 410, which are position detectors, are provided.
b and Y detected by X interferometers 414a and 414b
X axis 4 of X stage 401 with respect to stage 402
The rotation in the 20 directions and the rotation around the Z axis 421 is a driving mechanism without detecting the rotation of the X stage 401 around the Y axis 421 about the center of gravity because the movement of the center of gravity of the X stage 401 is observed. It is possible to detect a movement only in a direction that can be directly driven by the linear motor with high sensitivity, and to control the position and the posture.

FIG. 7 is a schematic view of a processing apparatus using an XY stage to which the present invention is applied. X stage 401 is X
The structural member of the Y stage 402 is supported as a guide so as to be movable in the movable direction of
It can move in the Y direction together with the stage 401. The Z stage 424 includes the gate frames 423a, 423b, 423
It moves in the Z-axis 421 direction along c. X stage 40
1, a workpiece 427 is mounted on the Z stage 424.
Has a spindle 425 that rotates at high speed around the X axis 419
Is mounted, and a machining tool 426 is attached to the spindle 425, and is rotated by the spindle 425. The processing tool 426 together with the Z stage 424 moves in the Z-axis 421 direction,
The workpiece 427 moves in the directions of the X axis 419 and the Y axis 420 together with the X stage 401 and the Y stage 402, and the workpiece 427 is processed at a processing point where the two come into contact. The positions of the X stage 401, the Y stage 402, and the Z stage 424 are measured based on the surface plate 422, and the positions of the workpiece 4
By controlling the relative position between the workpiece 27 and the processing tool 426, the processing point is changed, and the workpiece 427 is processed.

In the processing apparatus having the above-described configuration, by using the movable stage on which the control according to the present invention is performed, the workpiece and the processing tool are brought into contact with each other at the time of processing, thereby performing the processing operation. Even if a laser error occurs in one of the lasers for length measurement, the stage can be driven by using another laser and maintaining the same attitude as before the laser error occurred Becomes

[0089]

As described above, according to the present invention,
In a stage in which the position of the stage in the rectilinear direction is detected by a plurality of position detectors, and the position and orientation of the stage in the rectilinear direction are detected and controlled based on the average value and difference, any one of the plurality of position detectors Even if the state becomes undetectable, by making it possible to continue control without changing the position and attitude in the straight-ahead direction using another position detector without emergency stop, During processing, the stage can be controlled and moved to a safe place without damaging the tool or the workpiece due to the stop of the stage or a change in posture due to the occurrence of an error in the position detector.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a stage control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a stage control method according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a stage control method according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a stage control method according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating a stage control method according to a second embodiment of the present invention.

FIG. 6 is a perspective view illustrating a configuration of an XY stage controlled in a second embodiment of the present invention.

FIG. 7 is a perspective view showing an example of a processing machine using an XY stage controlled in a second embodiment of the present invention.

FIG. 8 is a flowchart of a conventional control method.

[Explanation of symbols]

1: X stage, 2: guide, 3a, 3b: LM (linear motor) movable magnet part, 4a, 4b: LM (linear motor) fixed coil part, 5: movable direction, 6: yawing direction, 7a, 7b: reflection Mirror, 8a, 8b: laser length measuring instrument interferometer, 9a, 9b: laser optical axis, 10a, 10b:
Laser length measuring device counter, 11: control device, 12: DSP for control calculation, 13: memory for gain storage, 14: memory for correction database, 15a, 15b: current amplifier for linear motor, 16: X direction, 17: Y Direction, 201-2
37: processing in the control device, 301 to 310: processing in the control device, 401: X stage, 402: Y stage, 40
3: Guide for X stage, 404: Guide for XY stage, 405a, 405b: Guide for Y stage, 406
a, 406b: X linear motor movable part (magnet), 407
a, 407b: X linear motor fixed part (coil), 40
8a, 408b: Y linear motor movable part (magnet), 40
9a, 409b: Y linear motor fixed part (coil), 4
10a, 410b: X stage reflection mirror, 411: Y
Stage reflection mirror, 412: X bar mirror, 413:
Y bar mirrors, 414a, 414b: X laser length measuring instrument interferometer, 415a, 415b: X laser length measuring instrument laser optical axis, 416a, 416b: Y laser length measuring instrument interferometer, 41
7a, 417b: laser beam axis of Y laser length measuring device, 418
a, 418b: Y interferometer table, 419: X-axis direction, 42
0: Y-axis direction, 421: Z-axis direction, 422: Surface plate, 42
3a, 423b, 423c: portal frame, 424: Z
Stage, 425: spindle, 426: machining tool, 4
27: Workpiece, 601 to 613: Processing in the control device.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (31)

[Claims] A plurality of position detectors for detecting a movement amount of the movable stage in a linear direction, a driving mechanism for driving the stage, and an output of the position detector. And a control device for controlling the driving mechanism, wherein the stage is moved straight by using an output of another position detector without using at least one of the plurality of position detectors. A stage control method comprising a gain storage step of storing a gain for controlling a direction. 2. The plurality of position detectors detects a position in the straight traveling direction with reference to a plurality of positions of the stage which is constrained and supported by guide means and moves integrally in the straight traveling direction, and a plurality of position data detected simultaneously. 2. The stage control method according to claim 1, wherein an average value of the stage is detected as a moving amount in a straight traveling direction, and a moving amount of the stage in a rotating direction can be detected based on a difference between a plurality of position data detected at the same time. . 3. The stage control method according to claim 1, wherein the driving mechanism is capable of driving the stage in a straight traveling direction and a rotating direction that can be detected by the plurality of position detectors. 4. The stage control according to claim 2, wherein the control device controls the positions in the straight traveling direction and the rotational direction detected by the plurality of position detectors via the driving mechanism. Method. 5. In the gain storing step, all of the plurality of position detectors are used as a calculation formula of a control operation performed by the control device and a gain which is a coefficient thereof, and a straight traveling direction and a rotation direction are optimally controlled. Normal gain, and a number corresponding to the number of all position detectors used to optimally control the position in the straight direction without using any one of the plurality of position detectors 5. The stage control method according to claim 2, wherein the abnormal gain is stored. 6. The position difference data of each position detector obtained by subtracting a target position from position data, which is a detection value of a position detector at each target position at a constant interval in a straight traveling direction, which is given to the control device, and the driving A database storing step of storing a thrust command value in the rotation direction for the mechanism, and when all of the position detectors can perform normal position detection, the normal-time gain is used, and all of the position detections are performed. The position and the attitude in the straight-moving direction and the rotation direction are calculated by the controller as the feedback signal using the position in the straight-moving direction and the rotation direction detected by the device, and the thrust command value in the straight-moving direction and the thrust command value in the rotating direction are calculated by the control device. If any of the plurality of position detectors becomes abnormal and the position cannot be detected, the position detector at the fixed interval stored in the database storage step is used. Among the data for each position, the difference data, which is stored at the target position closest to the current target position and is the difference from the target value in the straight direction of all the position detectors that do not cause abnormality, and the driving in the rotation direction A thrust command value to the mechanism is read from the data stored in the database storage step, and a thrust command value read from the database storage step is given as a thrust command value in the rotational direction of the drive mechanism, and a position detector that does not cause an abnormality. Detects the current position in the straight-ahead direction, and subtracts the average value of the difference data from the current position other than the position detector that caused the abnormality as a feedback signal. Control is performed by performing control calculation in the control device using the abnormal gain that can be controlled, and giving a thrust command in the straight traveling direction to the drive mechanism. Stage control method according to claim 5, characterized in that. 7. A plurality of X-direction position detectors for controlling a two-axis stage having an X stage and a Y stage to detect the amount of movement of the X stage in the X direction, and the amount of movement of the Y stage in the Y direction A plurality of Y-direction position detectors, an X-direction drive mechanism for driving the X stage,
A stage control method using a Y-direction drive mechanism for driving a stage, and a control device for controlling the X-direction drive mechanism and the Y-direction drive mechanism based on outputs of the X-direction position detector and the Y-direction position detector And a gain for storing a gain for performing control of the X-stage in the straight-ahead direction by using an output of another X-direction position detector without using at least one of the plurality of X-direction position detectors. A stage control method comprising a storage step. 8. The X-stage is restrained and supported by the Y-stage by guide means, and the plurality of X-direction position detectors detect a plurality of positions by using a plurality of positions of the X-stage as reference points. 8. The method according to claim 7, wherein an average value of the plurality of detected position data is determined as a moving amount in a straight traveling direction, and a difference between the plurality of detected position data is detected as a moving amount of the X stage in a rotating direction. Stage control method. 9. The Y-direction position detector detects a position in the Y-direction by using, as a reference point, a position on the Y-stage that moves along a straight-moving direction in the Y-axis direction along with the X-stage as a movable direction. The stage control method according to claim 7. 10. The X-direction driving mechanism includes a plurality of X-direction driving mechanisms.
The stage control method according to any one of claims 7 to 9, wherein the X stage can be driven in the X-direction linear and rotational directions that can be detected by a direction position detector. 11. The device according to claim 7, wherein the Y-direction driving mechanism is capable of driving the Y-stage in a Y-direction rectilinear direction that can be detected by the Y-direction position detector. Stage control method. 12. In the gain storage step, all of the X-direction position detectors are used as a calculation formula of a control calculation in the X-direction performed by the control device and a gain which is a coefficient thereof, and the linear motion direction and the rotation in the X-direction are used. In order to optimally control the normal direction gain for optimally controlling the direction and the position in the X-direction linear direction without using any one of the X-direction position detectors among the plurality of X-direction position detectors. The method according to claim 1, further comprising: storing a plurality of emergency abnormality gains corresponding to the number of all the X-direction position detectors to be used, and a gain switching step of switching the gain stored in the gain storage step. 12. The stage control method according to any one of 7 to 11. 13. An X-direction linear target position obtained by subtracting the X-direction linear target position from position data, which is a detection value of the X-direction position detector, for each target position given to the control device at predetermined intervals in the X and Y directions. A database storing step of storing position difference data for each X-direction position detector and a thrust command value in the rotational direction for the X-direction drive mechanism, in a case where all the position detectors can perform normal position detection. The thrust command in the straight-moving direction to the X-direction drive mechanism is sent to the X-direction drive mechanism by the control device as a feedback signal using the normal gain and the positions in the straight-moving direction and the rotating direction in the X direction detected by all the position detectors. Value and the thrust command value in the rotational direction are calculated to control the position and orientation. One of the plurality of X-direction position detectors becomes abnormal and the position cannot be detected. If the situation occurs, the data is stored at the target position closest to the current target position among the data for the target positions in the X and Y directions at regular intervals stored in the database storage step, and an abnormality has occurred. The difference data, which is the difference from the target value in the X direction of the X direction of all the X direction position detectors, and the thrust command value to the drive mechanism in the rotation direction are read from the data stored in the database storage step. A thrust command value read from the data stored in the database storage step is given as a thrust command value in the rotation direction of the drive mechanism, and the current position in the straight traveling direction is detected by the X-direction position detector having no abnormality, and the X-direction is detected. The X-direction position detector in which no abnormality has occurred is determined as a feedback signal by subtracting the average value of the difference data other than the position detector in which abnormality has occurred from the current position of the X-direction position detector. Control is performed by the control device using the abnormal time gain that enables optimal control in the straight-ahead direction, and control is performed by giving a thrust command in the straight-ahead direction to the X-direction drive mechanism. The stage control method according to claim 12. 14. When all the position detectors are in a normal state, a target position is given to the control device, and when the stage is moved, data stored in the database storage step is constantly updated for each target position. 14. The stage control method according to claim 6, wherein the control is continued. 15. Each of the driving mechanisms is a plurality of linear motors, and a thrust in a straight traveling direction is given by a sum of thrusts of the plurality of linear motors, and a thrust in a rotating direction is determined by some of the plurality of linear motors. The stage control method according to claim 1, wherein the difference is given by a difference in thrust of the linear motor. 16. The apparatus according to claim 2, wherein said guide means is an air bearing.
The stage control method according to any one of the above. 17. A movable stage, a plurality of position detectors for detecting the amount of movement of the stage in the straight direction, a driving mechanism for driving the stage, and the driving based on an output of the position detector. A drive mechanism control device for controlling a mechanism, and a gain for performing the control of the stage in the rectilinear direction using outputs of other position detectors without using at least one of the plurality of position detectors. A stage control device comprising a gain storage memory for storing. 18. A plurality of position detectors, wherein the plurality of position detectors are constrained and supported by guide means and detect positions in the straight-moving direction with reference to a plurality of positions of the stage moving integrally in the straight-moving direction. 18. The stage control device according to claim 17, wherein an average value of the stage is detected as a moving amount in a straight traveling direction, and a moving amount of the stage in a rotating direction is detected based on a difference between a plurality of position data detected at the same time. 19. The stage control device according to claim 17, wherein the drive mechanism is capable of driving the stage in a straight-ahead and rotational direction that can be detected by the plurality of position detectors. 20. The gain storage memory according to claim 1, wherein a calculation expression of a control operation performed by the drive mechanism control device and a gain which is a coefficient thereof are optimized in a straight traveling direction and a rotation direction by using all of the plurality of position detectors. Normal gain to be controlled, and the number of all position detectors used to optimally control the position in the straight direction without using any one of the plurality of position detectors. 20. The stage control apparatus according to claim 17, wherein a plurality of commensurate abnormal gains are stored. 21. Position difference data for each position detector obtained by subtracting a target position from position data, which is a detection value of a position detector for each target position at a predetermined interval in a straight-forward direction, which is given to the drive mechanism controller, and A database storage memory that stores a thrust command value in the rotation direction for the drive mechanism is provided.If all the position detectors can perform normal position detection, the normal gain is used, and all the position detectors are used. The drive mechanism controller calculates the thrust command value in the straight direction and the thrust command value in the rotation direction to the drive mechanism by using the position in the straight direction and the rotation direction detected by the position detector as a feedback signal. Performing control, when any of the plurality of position detectors become abnormal and the position cannot be detected, the database storage memory The difference, which is the difference between the target value in the straight-ahead direction of all position detectors that are stored at the target position closest to the current target position and that are not abnormal, of the data for each target position at fixed intervals. The data and the thrust command value to the drive mechanism in the rotation direction are read from the database storage memory, and the thrust command value read from the database storage memory is given as the thrust command value in the rotation direction of the drive mechanism, and no abnormality occurs. The position detector detects the current position in the straight traveling direction with the position detector, and a value obtained by subtracting an average value of difference data other than the position detector having an abnormality from the current position as a feedback signal, the position detector having no abnormality In the drive mechanism control device, a control calculation is performed using the abnormal time gain that can optimally control the straight ahead direction, and the straight forward direction to the drive mechanism is controlled. Stage control device according to claim 20, wherein the performing control by providing a force command. 22. An apparatus having an X stage and a Y stage.
A plurality of X-direction position detectors for detecting the amount of movement of the X stage in the X direction, and a plurality of Y-direction position detectors for detecting the amount of movement of the Y stage in the Y direction; An X-direction drive mechanism for driving the X stage, a Y-direction drive mechanism for driving the Y stage, and the X-direction drive mechanism based on the outputs of the X-direction position detector and the Y-direction position detector.
A driving mechanism control device for controlling the direction driving mechanism and the Y direction driving mechanism, and using the output of another X direction position detector without using at least one of the plurality of X direction position detectors.
A stage control device, comprising: a gain storage memory for storing a gain for performing control of a stage in a straight traveling direction. 23. The X stage, wherein the X stage is restrained and supported by the Y stage by guide means.
The direction position detector detects a plurality of positions by using a plurality of positions of the X stage as reference points, sets an average value of the plurality of position data detected at the same time as a moving amount in the straight traveling direction, and calculates a difference between the plurality of position data detected simultaneously. 23. The stage control device according to claim 22, wherein the detection is performed as a movement amount of the X stage in a rotation direction. 24. The Y-direction position detector detects a position in the Y-direction by using, as a reference point, a position of the Y-stage that moves along a straight-moving direction in the Y-axis direction with the X-stage as a movable direction. The stage control device according to claim 22. 25. The X-direction drive mechanism, wherein the plurality of X-direction drive mechanisms
The stage control device according to any one of claims 22 to 24, wherein the X stage can be driven in a linear direction and a rotational direction of the X direction that can be detected by a direction position detector. 26. The Y-direction drive mechanism is capable of driving the Y-stage in a Y-direction rectilinear direction detectable by the Y-direction position detector.
The stage control device according to any one of the above. 27. The gain storage memory uses all of the X-direction position detectors as a calculation formula of a control calculation in the X-direction performed by the drive mechanism control device and a gain which is a coefficient thereof, and proceeds straight in the X-direction. Normal gain for optimally controlling the direction and rotation direction, and among a plurality of X-direction position detectors,
Without using any one of the X-direction position detectors, storing a number of abnormal gains corresponding to the number of all the position detectors used to optimally control the position in the X-direction linear direction,
The stage control device according to any one of claims 22 to 26, further comprising: a gain switching unit that switches a gain stored in the gain storage memory. 28. A linearly moving target position in the X direction is subtracted from position data, which is a detection value of the X direction position detector, for each target position provided to the driving mechanism control device at fixed intervals in the linearly moving directions in the X and Y directions. A database storage memory for storing position difference data for each X-direction position detector and a thrust command value in the rotation direction for the X-direction drive mechanism, so that all the position detectors can perform normal position detection. If possible, the normal gain is used, and the X-direction drive mechanism is used by the drive mechanism control device as a feedback signal based on the positions in the X-direction straight-ahead direction and the rotation direction detected by all the X-direction position detectors. Calculating the thrust command value in the straight traveling direction and the thrust command value in the rotation direction to control the position and orientation, and among the plurality of X-direction position detectors, any one of the X-direction position detectors In the case where it is abnormal and the position cannot be detected, the target position closest to the current target position among the data for the target positions in the X and Y directions at regular intervals stored in the database storage memory. The difference data, which is the difference between the X-direction position detectors in the X-direction that are not abnormal and the target values in the X-direction, and the thrust command value to the drive mechanism in the rotation direction are read from the database storage memory. A thrust command value read from the database storage memory is given as a thrust command value in the rotation direction of the X-direction drive mechanism, and the X-direction position detector having no abnormality detects a current position in the straight-ahead direction. A value obtained by subtracting the average value of the difference data from the current position of the other than the position detector that caused the abnormality is used as a feedback signal. The control is performed by performing a control calculation in the drive mechanism control device using the abnormal time gain capable of appropriately controlling the straight traveling direction, and giving a thrust command in the straight traveling direction to the X-direction drive mechanism in which no abnormality has occurred. The stage control device according to claim 27, wherein the control is performed. 29. When all the position detectors are in a normal state, a target position is given to the drive mechanism control device, and when the stage is moved, data stored in the database storage memory is always stored for each target position. 29. The stage control device according to claim 21, wherein the stage control device keeps updating. 30. Each of the driving mechanisms is a plurality of linear motors, and a thrust in a straight traveling direction is given by a sum of thrusts of the plurality of linear motors, and a thrust in a rotating direction is determined by some of the plurality of linear motors. 30. The stage control device according to claim 17, wherein the difference is given by a difference in thrust of the linear motor. 31. An air bearing according to claim 18, wherein said guide means is an air bearing.
30. The stage control device according to any one of claims to 29.