JP3484583B2 - Precision positioning control method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision positioning control method used for connecting a relative moving member such as a light emitting device or a light receiving device to an optical fiber.

[0002]

2. Description of the Related Art In recent years, with the progress of optical communication technology, 1.55
Single-mode communication using light with a wavelength of μm is becoming mainstream. Single-mode fibers have a core diameter of 10 μm or less.
A positioning accuracy of about μm is required, and when considered as an automatic positioning system, it is necessary to secure a stroke of several mm at the same time.

In order to satisfy such a moving function, for example, a stage having a coarse movement axis and a fine movement axis separately is often used. As such a positioning control method, for example, there is a method in which a coarse movement positioning position detection device and a fine movement positioning position detection device are provided independently. Japanese Patent Laid-Open No. 63-299785 proposes a mechanism that can perform a coarse movement and a fine movement by one mechanism as a minute positioning device that uses the impact force of a piezoelectric actuator element. With this method, theoretically one mechanism can realize a wide stroke and a positioning accuracy of about 0.1 μm.

[0004]

However, in the conventional stage apparatus having a coarse movement axis and a fine movement axis separately, the coarse movement and fine movement mechanisms are complicated and problems such as interference between controls occur. Further, the method disclosed in Japanese Patent Laid-Open No. 63-299785 has the following problems. The control is to perform positioning control by sequentially creating a drive waveform in an analog manner using a method such as PID control with respect to a positioning command value, and controls a fine waveform parameter (voltage change acceleration, voltage rapid change time). In order to perform precise positioning, it took time to create a waveform, and it took time to create a waveform, and the conventional dedicated controller only controls the voltage difference of the drive waveform as a waveform parameter. Had the problem of being difficult to control.

The present invention has been made in order to solve the various problems of the prior art as described above, and its purpose is to perform coarse positioning without the need for the complicated two control systems of the prior art. Another object of the present invention is to provide a precise positioning control method capable of performing fine movement positioning with one mechanism and one control system and greatly simplifying the precise positioning mechanism. Another object of the present invention is to provide a precise positioning control method which does not require an extremely troublesome operation and is much easier to perform precise positioning, unlike the method described in Japanese Patent Laid-Open No. 63-299785 mentioned above. Is to provide.

[0006]

The present invention which achieves the above object is described as follows. It is a method for driving a moving stage comprising a moving stage and a piezoelectric actuator element having an inertial body, which is connected to the moving stage. A control device for operating the moving stage has a read-only memory and a central processing unit for reading the read-out memory to perform the processing described later, and the read-only memory has a pulse-shaped waveform.
Voltage height, voltage change acceleration and voltage rapid change time
A pulsed waveform with a gentle falling edge and a sudden rising edge formed by a meter , or a pulsed waveform with a gentle rising edge and a sudden falling edge, with different valley depths. A plurality of types of waveforms created in advance with optimum parameters for each movement amount are stored, the waveforms are read out by the central processing unit, the number of each of the plurality of types of waveforms is determined, and the command target of the moving stage is determined. Is a precision positioning control method in which the moving stage is driven by combining the pulse-shaped waveforms so that the depth of the valleys thereof gradually decreases near the end point and outputting the combined pulse-shaped waveforms.

[0007] The connecting movable stage and to a method of driving the movable stage consisting of a piezoelectric actuator element having inertial body, the control device for actuating the moving stage and read only memory, read this Te has a central processing unit for the later processing, and the read-only memory, the voltage level and the voltage variations of the pulse-shaped waveform
Formed by the parameters of the acceleration and the rapid voltage change time.
The, a pulse waveform having a gentle fall and sudden竣rise portion, or gentle rise and steep竣of a pulse-shaped waveform having a falling portion, and the depth is more than one kind of the valley Of the optimum parameters for each movement
The created waveform is stored, the waveform is read by the central processing unit, the number of each of the plurality of types of waveforms is determined, and the depth of the trough of the pulse waveform near the end point of the command target of the moving stage is determined. Is a precision positioning control method in which a plurality of the moving stages are driven by switching through a relay circuit according to the output of the combined pulse-shaped waveform so as to decrease gradually. Further, the moving stage detects the position after moving by means for detecting the position of the moving stage corresponding to this,
Based on the information, the number of the same waveforms as the appropriate waveforms among a plurality of types of pulse-shaped waveforms recorded from the read-only memory is determined, and the determined output drives the remaining movement amount of the moving stage. This is a positioning control method. Further, the plurality of types of pulse-like waveforms correspond to at least the following movement amounts of the moving stage, respectively, in the precision positioning control method. 10 μm 1 μm 0.1 μm

[0008]

The present invention is configured as described above, and when driving the moving stage, the waveform having a gentle falling edge and a sudden rising edge from the read-only memory,
Or, the type and number of waveforms having a gentle rise and a sharp fall, and those with different valley depths,
Since it is determined by the central processing unit and taken out and the moving stage is driven by the output, it is possible to eliminate the trouble of handling the two control systems of the coarse movement and the fine movement as in the conventional case, and it is extremely easy. Precise positioning control can be performed. Further, the above-mentioned conventional example, JP-A-63-29978.
As in the method described in No. 5, it is possible to eliminate the troublesome work and time for creating a pulse-like waveform by determining the voltage change acceleration at each moment, the voltage rapid change time, etc. when driving the moving stage. When using the conventional dedicated controller,
Although only the voltage difference of the drive waveform can be controlled, and precise positioning was difficult to control, the method of the present invention makes it extremely easy. Moreover, in the combination of pulse-like waveforms,
By gradually decreasing the depth of the valleys, it is possible to automatically stop the moving stage with deceleration when stopping the moving stage, and eliminate the risk of vibration or overshoot at the time of stopping.

The output of the central processing unit of the present invention is
A device that outputs to a plurality of moving stages by switching through a relay circuit can very easily drive a precision positioning device composed of an X-axis Y-axis or a precision positioning device composed of an X-axis Y-axis Z-axis. . In addition, a plurality of types of pulse-shaped waveforms corresponding to at least the moving amounts of 10 μm, 1 μm, and 0.1 μm shown below on the moving stage can perform coarse movement and fine movement almost continuously. Therefore, at the end of the driving, the stop accompanied by deceleration can be automatically performed, there is no stage vibration, and the risk of overshoot can be eliminated.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention, and is a schematic front view of an apparatus used for a precision positioning method, and FIG. 2 is a schematic sectional view of the same precision positioning apparatus. In FIG. 1, 1 is a piezoelectric actuator element, 2 is an inertial body, 3 is a moving stage, 4 is a precision guide groove, and 5 is an adjustment for applying a predetermined frictional force to the moving stage 3 using the precision guide groove 4. It is a screw.

Next, the principle of movement of this precision positioning device will be briefly described. As shown in FIG. 3, the piezoelectric actuator element 1 is provided between the moving stage 3 and the inertial body 2.
5 and 6 are arranged on the piezoelectric actuator element 1.
The moving stage 3 is moved by rapidly deforming by adding a pulsed waveform as shown in FIG. As the movement concept, parameters by the waveform shape of the pulse-like waveform voltage level 7 and the voltage change acceleration 8 and the voltage rapidly changes time 10 can optionally form, the moving amount per waveform is defined. By inputting this into the piezoelectric actuator element 1 as a continuous waveform, it is possible to realize stepwise movement in pulse units. Table 1 shows an example of the contents of the read-only memory, which is used.

[0012]

[Table 1]

FIG. 5 shows a forward waveform and FIG. 6 shows a backward waveform. The slope 8 indicates the acceleration of the voltage change, and the height 7 indicates the voltage difference. Further, 10 is a rapid voltage change time. Next, FIG. 4 is a block diagram showing a positioning control configuration of the present invention, and FIG. 7 is a diagram showing an example of contents of a read-only memory for storing waveform data. Positioning control will be described with reference to this figure.

First, the target position command is sent to the bus 13 of the central processing unit in the controller 12 by using a means such as the hand operation panel 11, and the command value is applied to the waveform data and the number of times of application in a preprogrammed processing method. And the desired waveform is taken out from the read-only memory 14 for storing waveform data, the positioning direction and the number of times of application are preset in the output waveform counter 15, and the output waveform counter 15 is set to 0.
Drive waveform data is output to the piezoelectric actuator element drive power supply 16 through the D / A converter 16 to drive the moving stage 3 and converge the positioning based on the signal from the position sensor 17. There is.

Next, the operation of the above embodiment will be described.
As an example, in the positioning system in which the waveform table as shown in FIG. 7 is prepared for the waveforms having the shapes shown in FIGS.
A movement command to 4 μm was input. The controller 12 recognizes that the moving direction is the forward direction, and 1053.4 μm (10
Waveform read-only memory 14
To NO. The waveform data is taken out in the forward direction of the waveform data of 1, and the output waveform counter 15 is set to 105 times,
Output to the piezoelectric actuator element drive power supply 15. The moving waveform amplified by the piezoelectric actuator element driving power supply 15 causes the moving stage 3 to start moving toward the commanded position. After the first positioning is completed, the current position is measured by the position sensor 17, this control is performed again with respect to the positioning error portion, the waveform data is selected from the read-only memory 14 and the driving frequency is calculated. To move. This operation was repeated until the error was within the preset error range, and the preset position of 0.1 μm in accuracy was completed in 3 seconds. FIG. 9 is a graph showing the concept of a positioning process using a conventional pulse motor, and FIG. 10 is a concept of the above-described operation process.

Further, this control is not limited to the above-mentioned example. First, the combination of waveforms and the number of times of driving thereof are obtained and moved at once, the current position is measured by the position sensor 17, and the optimum combination is recalculated. Such control may be used. The position sensor 17 is not limited to those normally used such as the A / B phase, the up / down waveform, and the analog voltage, and is not particularly limited by the sensor used.

Further, the forward waveform and the backward waveform may be combined, and the present invention can be applied to open loop control which does not use a position sensor having a positioning accuracy of about 1 μm. The point is that positioning is performed by using the waveform data prepared in advance so that the optimum combination is calculated.

Next, another embodiment of the present invention will be described with reference to FIG. The movement command input from the hand operation panel 11 is divided into a driving waveform and a driving number for each axis in the positioning controller 12. Thereafter, the positioning controller 12 opens the output gate to the X stage 19 in the relay circuit 18 installed at the output end of the piezoelectric actuator element driving power supply 15 and applies a driving waveform to perform positioning. Then, Y, Z The same control is performed in the stages 20 and 21 to complete the movement command. It should be noted that the control axes are not limited to three axes, and when the moving speed is important, power sources may be prepared for the number of axes, and this structure does not limit the above embodiment.

[0019]

As described above, according to the present invention, a waveform having a gradual fall and a sudden rise from a read-only memory, or a waveform having a gradual rise and a sudden fall, and The type and number of those waveforms having different valley depths are determined by the central processing unit and taken out, and the moving stage may be driven by the output thereof. It is possible to eliminate the trouble of handling the two control systems, and it is possible to perform precision positioning control extremely easily. Further, as in the method described in JP-A-63-299785 of the conventional example,
When driving the moving stage, it is possible to eliminate the troublesome time and time required to determine the voltage change acceleration, the voltage change time, and the like at each moment to create the pulse waveform. Also, when using the conventional dedicated controller, only the voltage difference of the drive waveform can be controlled, which is difficult to control for precise positioning.
According to the method of the present invention, it can be done very easily. Also, in the combination of pulse-like waveforms, by gradually decreasing the depth of the valleys, it is possible to automatically stop with deceleration when stopping the moving stage, and there is a fear of vibration or overshoot at the time of stopping. Can be eliminated.

The output of the central processing unit of the present invention is
What is output to a plurality of moving stages via a relay circuit is, for example, a precision positioning device composed of an X axis and a Y axis, or X
The precision positioning device consisting of the axes Y-axis and Z-axis can be driven very easily. In addition, a plurality of types of pulses are applied to the moving stage at least with the following movement amounts of 10 μm and 1 μm.
m and 0.1 μm, respectively, can perform coarse and fine movements almost continuously, so that at the end of driving, stop accompanied by deceleration can be automatically performed, and stage vibration And there is no fear of overshoot.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a precision positioning device for explaining an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a precision positioning device for explaining an embodiment of the present invention.

FIG. 3 is a diagram for explaining the movement principle of the present invention.

FIG. 4 is a block diagram showing a precision positioning control method for explaining an embodiment of the present invention.

FIG. 5 is a drive waveform for forward movement for explaining the embodiment of the present invention.

FIG. 6 is a drive waveform for backward movement for explaining the embodiment of the present invention.

FIG. 7 is a diagram showing the internal structure of a read-only memory for storing waveform data according to the embodiment of the present invention.

FIG. 8 is a diagram of a precision positioning method according to another embodiment of the present invention.

FIG. 9 is a graph showing a process of a conventional method.

FIG. 10 is a graph showing the process of the method of the present invention in relation to a pulsed waveform.

[Explanation of symbols]

1 Piezoelectric actuator element 2 inertial body 3 moving stages 4 Precision guide groove 5 Adjustment screw 7 Voltage height 8 Voltage change acceleration gradient 9 Voltage rapid deformation waveform 10 Rapid voltage change time 11 Hand control panel 12 Precision positioning controller 13 Central processing unit 14 Waveform data read-only memory 15 Piezoelectric actuator element drive power supply 16 D / A converter 17 Position sensor 22 pulse counter 23 Output waveform counter

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G05D 3/00-3/20 G12B 1/00-17/08 H02N 1/00-15/04 H01L 41/00-41 / 22 B23Q 5/00-5/58 G05B 19/18

Claims (4)

(57) [Claims] 1. A method of driving a moving stage comprising a moving stage and a piezoelectric actuator element having an inertia body connected to the moving stage, wherein a control device for operating the moving stage has a read-only memory and a read-only memory. a central processing unit for the later processing by reading, in the read only memory includes a voltage level of the pulse-shaped waveform
Depending on the parameters of voltage change acceleration and voltage rapid change time
A pulsed waveform that has a gentle falling edge and an abruptly rising edge, or a pulsed waveform that has a gentle rising edge and an abruptly falling edge, and has different valley depths. A type of waveform is stored in advance with optimum parameters for each movement amount, the waveform is read by the central processing unit, and the number of each of the plurality of types of waveforms is determined. A precise positioning control method in which the depths of the valleys of the pulse waveform are gradually reduced near the end point, and the moving stage is driven by the output of the pulse waveform of the combined waveform. 2. A connecting movable stage and to a method of driving the movable stage consisting of a piezoelectric actuator element having inertial body, the control device for actuating the moving stage and read-only memory, this reading a central processing unit for the later processing, the said read-only memory, the voltage level of the pulse-like waveform and electrostatic
Shaped by parameters of pressure change acceleration and voltage rapid change time
It made a, and a pulse-shaped waveform having a gentle fall and sudden竣rise portion, or gentle rising and pulsed waveform having a steep竣a falling portion, and are multiple depths of valleys Parameters of each type of movement
The waveform created in advance is stored by the central processing unit, the waveform is read by the central processing unit, and the number of each of the plurality of types of waveforms is determined. A precision positioning control method in which a plurality of the moving stages are driven by switching the outputs of pulse-shaped waveforms of the combined waveforms that are combined so that the depth gradually decreases. 3. The moving stage detects the position after the movement by means for detecting the position of the moving stage corresponding to the moving stage, and further, based on the information, the plurality of types of pulse patterns recorded from the read-only memory. 3. The precision positioning control method according to claim 1 or 2, wherein the number of the same waveforms as the appropriate waveforms among the waveforms of 1. is determined, and the remaining movement amount of the moving stage is driven by the determined output. 4. The precision positioning control method according to claim 1, wherein each of the plural kinds of pulse-like waveforms corresponds to at least the following movement amount of the moving stage. 10 μm 1 μm 0.1 μm