Measurement device

Abstract

The present invention improves positioning accuracy in a positioning device. Provided is a measurement device for a system having a drive mechanism for moving an object in one direction by means of a plurality of drive units, the measurement device comprising: control units (4a, 4b) that output a plurality of drive signals (D1) for respectively controlling the plurality of drive units (2a, 2b); detection units (3a, 3b) that output detection signals (D2) indicating detection results of the drive states of the drive units (2a, 2b); and measurement units (5a, 5b). The plurality of drive signals (D1) are in-phase or reverse-phase drive signals. When the plurality of drive signals (D1) are simultaneously inputted from the control units (4a, 4b) to the each of the plurality of drive units (2a, 2b), the measurement units (5a, 5b) measure the frequency characteristics of the system in accordance with the drive signals (D1) and the detection signals (D2).

Description

Measuring apparatus

[0001] The present disclosure relates to a measuring apparatus that measures frequency characteristics of a system having a drive unit for moving an object.

[0002] Conventionally, control devices that control a drive unit for moving an object have been used in industrial machines such as manufacturing apparatuses for electronic devices and various processing apparatuses. For example, Patent Document 1 discloses a motor control device capable of measuring mechanical characteristics including between multiple axes including a motor used with a large stroke under a condition where a vertical axis or an external force is applied, grasping the stability of a controller, and grasping the adjustment degree of the controller including between axes according to the mechanical characteristics.

[0003] Japanese Patent No. 5190803

[0004] Incidentally, a plurality of drive mechanisms are sometimes used to position an object. For example, the object is positioned by rotationally and translationally moving the object via the plurality of drive mechanisms. In this case, when the object is rotationally moved and translationally moved, respective frequency characteristics may differ. For this reason, if the frequency characteristics with respect to the movement direction cannot be grasped, the movement speed or positioning accuracy will decrease.

[0005] The present disclosure aims to provide a measuring apparatus for improving the movement speed or positioning accuracy of an object.

[0006] To achieve the above object, a measuring apparatus according to the present disclosure is a measuring apparatus for a system having a drive mechanism that moves an object in one direction by a plurality of drive units. The measuring apparatus includes a control unit, a detection unit, and a measurement unit. The control unit outputs a plurality of drive signals that respectively control the plurality of drive units. The detection unit outputs a detection signal indicating a detection result of the drive state of the drive units to the control unit. The plurality of drive signals are in-phase or anti-phase drive signals. When the plurality of drive signals are simultaneously input from the control unit to the respective plurality of drive units, the measurement unit measures the frequency characteristics of the system according to the drive signals and the detection signal.

[0007] According to the present disclosure, the movement speed or positioning accuracy in a positioning apparatus can be improved.

[0008] A schematic diagram showing the configuration of the measuring device according to the first embodiment. An enlarged view of the area around the object in the measuring device according to the first embodiment. An enlarged view of the area around the object in the measuring device according to the first embodiment. A diagram showing an example of the screen displayed on the display according to the first embodiment. A diagram showing an example of the screen displayed on the display according to the first embodiment. A block diagram of the feedback control. An enlarged view of the area around the object in the measuring device according to a modified example of the first embodiment. A schematic diagram showing the configuration of the measuring device according to the second embodiment. An enlarged view of the area around the object in the measuring device according to the second embodiment. An enlarged view of the area around the object in the measuring device according to the second embodiment. An enlarged view of the area around the object in the measuring device according to a modified example of the second embodiment. An enlarged view of the area around the object in the measuring device according to a modified example of the second embodiment.

[0009] Embodiments of the present disclosure will be described below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0010] (First Embodiment) Figure 1 is a schematic diagram showing the configuration of a measuring device according to the first embodiment. As shown in Figure 1, the measuring device according to this embodiment comprises an object 1 (system), a drive unit 2a and a drive unit 2b, a detection unit 3a and a detection unit 3b, a control unit 4a and a control unit 4b, a measuring unit 5a and a measuring unit 5b, a command unit 6a, a display 7 (display unit), and a storage unit 8a and a storage unit 8b. The drive unit 2a and the drive unit 2b are each forms of a drive mechanism. The display 7 is a form of a display unit. The measuring device according to this embodiment is configured as part of a positioning device that positions the object 1.

[0011] Object 1 is, for example, a workpiece (object to be processed or inspected) such as an electronic component. If the drive mechanism is a gantry mechanism, then Object 1 is a beam.

[0012] The drive unit 2a and the drive unit 2b are drive mechanisms each having a motor. The drive unit 2a has a main shaft 21a extending in one direction. The drive unit 2b has a main shaft 21b extending in a direction parallel to the main shaft 21a. The main shafts 21a and 21b are, for example, ball screws. The drive unit 2a operates based on a drive signal D1 from the control unit 4a. The drive unit 2b operates based on a drive signal D1 from the control unit 4b.

[0013] More specifically, the drive unit 2a drives a motor based on the drive signal D1 from the control unit 4a, moving the object 1 mounted on the spindle 21a along the spindle 21a. The drive unit 2b drives a motor based on the drive signal D1 from the control unit 4b, moving the object 1 mounted on the spindle 21b along the spindle 21b. The operation of the drive units 2a and 2b causes the object 1 to move in parallel or rotationally. The motors for the drive unit 2a and spindle 21a together may be linear motors, or the motors for the drive unit 2b and spindle 21b together may be linear motors. The operation of the drive unit 2a and the drive unit 2b will be described later.

[0014] The detection unit 3a is, for example, a rotary encoder that detects the amount of rotation and speed of the drive unit 2a. The detection unit 3b is, for example, a rotary encoder that detects the amount of rotation and speed of the drive unit 2b. The detection unit 3a outputs a detection signal D2 indicating the detection result to the measurement unit 5a. The detection unit 3b outputs a detection signal D2 indicating the detection result to the measurement unit 5b.

[0015] Each of the control units 4a and 4b generates a drive signal D1 based on the drive command D3 (described in detail later) output from the command unit 6a. For example, control unit 4a converts the received drive command D3 into data indicating the drive direction of the drive unit 2a and outputs the converted data as a drive signal D1 to the drive unit 2a. Control unit 4b converts the received drive command D3 into data indicating the drive direction of the drive unit 2b and outputs the converted data as a drive signal D1 to the drive unit 2b. Each of the control units 4a and 4b may be, for example, a servo amplifier.

[0016] Each of the measurement units 5a and 5b is composed of, for example, a personal computer (PC). Each of the measurement units 5a and 5b generates a characteristic signal D4 that shows the frequency response characteristics of the object 1 based on the detection signal D2 and the drive command D3. The measurement unit 5a outputs the generated characteristic signal D4 to the storage unit 8a, and the storage unit 8a stores the data contained in the characteristic signal D4. The measurement unit 5a outputs the characteristic signal D4 to the display 7. The measurement unit 5b outputs the generated characteristic signal D4 to the storage unit 8b, and the storage unit 8b stores the data contained in the characteristic signal D4. The measurement unit 5b outputs the characteristic signal D4 to the display 7. Each of the measurement units 5a and 5b may be provided within the servo amplifier together with each of the control units 4a and 4b. Also, each of the measurement units 5a and 5b may be configured using an external device such as an FFT analyzer, separate from each of the control units 4a and 4b. Each of the measurement units 5a and 5b may be a PC, which may have a program or software for processing signals.

[0017] The command unit 6a outputs a drive command D3 indicating the drive pattern of the object 1. The drive command D3 is a sine wave or an M-sequence signal. The drive command D3 includes, for example, the drive direction of the drive unit 2a or drive unit 2b, its amplitude, the start time of the drive, and the end time of the drive as part of the drive pattern.

[0018] When the display 7 receives a characteristic signal D4 from the measurement unit 5a or the measurement unit 5b, it displays data indicating the frequency response characteristics included in the received characteristic signal D4. Note that the display 7 can be any display device (display unit) that can display the received data.

[0019] (Regarding the measurement method for frequency response characteristics) Figures 2A and 2B are enlarged views of the area around the object 1 in the measuring device according to the first embodiment. In each of Figures 2A and 2B, an XY Cartesian coordinate system is defined with the X axis parallel to the direction in which the two drive units 2a and 2b are arranged, and the Y axis perpendicular to the X axis. The drive unit 2b is positioned in the positive direction of the X axis as seen from the drive unit 2a. The object 1 is positioned across the main shafts 21a and 21b. More specifically, the object 1 is in contact with the main shaft 21a at a contact area 22a and with the main shaft 21b at a contact area 22b. As shown in Figures 2A and 2B, in the measuring device according to this embodiment, the drive unit 2a drives a motor. The drive unit 2b drives a motor. As a result, the main shafts 21a and 21b operate, respectively, and the contact areas 22a and 22b move along the Y axis. As a result, object 1 is translated along the Y-axis (see Figure 2A) and rotated (see Figure 2B).

[0020] More specifically, as shown in Figure 2A, if both contact area 22a and contact area 22b move by the same amount in the positive direction of the Y-axis, the object 1 moves in the positive direction of the Y-axis. Also, as shown in Figure 2B, if contact area 22a moves by the same amount in the positive direction of the Y-axis and contact area 22b moves by the same amount in the negative direction of the Y-axis, the object 1 rotates clockwise in the drawing. Note that the connection areas 22a and 22b may be, for example, components that connect the main spindles 21a and 21b to the object 1. These components may be provided on either the main spindles 21a and 21b or the object 1, or on both. Furthermore, these components may be tables mounted on a ball screw.

[0021] In this embodiment, the driving directions of the two drive units 2a and 2b along the Y-axis are either the same direction or opposite directions.

[0022] In this embodiment, the command unit 6a generates a drive command D3 (drive pattern) such that the amount of movement (amplitude) of the drive unit 2a in the drive direction and the amount of movement (amplitude) of the drive unit 2b in the drive direction are the same. Then, the control unit 4a generates a drive signal D1 in response to the drive command D3 and outputs it to the drive unit 2a. The control unit 4b generates a drive signal D1 in response to the drive command D3 and outputs it to the drive unit 2b. For example, as shown in Figure 2A, if the drive unit 2a moves the contact area 22a and the drive unit 2b moves the contact area 22b by the same amount in the positive direction of the Y axis, the object 1 moves in parallel in the positive direction of the Y axis (hereinafter referred to as "first operation"). Also, as shown in Figure 2B, if the drive unit 2a moves the contact area 22a in the positive direction of the Y axis and the drive unit 2b moves the contact area 22b in the negative direction of the Y axis, the object 1 rotates in the clockwise direction in the drawing (hereinafter referred to as "second operation"). In other words, in Figure 2A, drive signals D1 that are in phase with each other are input to drive unit 2a and drive unit 2b. In Figure 2B, drive signals D1 that are out of phase with each other are input to drive unit 2a and drive unit 2b. Note that "in phase" is defined as the case where the drive directions of drive unit 2a and drive unit 2b are in the same direction, and "out of phase" is defined as the case where they are in opposite directions.

[0023] At this time, the control units 4a and 4b output the drive signal D1 to the corresponding drive units 2a and 2b, respectively, in a timed manner so that the drive signal D1 (either in phase or out of phase) is simultaneously input to the drive units 2a and 2b. For this reason, the command unit 6a outputs a drive command D3 so that the drive signal D1 output from the control units 4a and 4b is simultaneously input to the drive units 2a and 2b.

[0024] In this embodiment, the measurement unit 5a and the measurement unit 5b measure the frequency response characteristics of the object 1 when a first operation (translational movement) and a second operation (rotational movement) are performed. Specifically, each of the measurement unit 5a and the measurement unit 5b generates a characteristic signal D4 indicating the frequency response characteristics of the object 1 based on the drive signal D1 (drive command D3) and the detection signal D2 when the first operation and the second operation are performed. The measurement unit 5a outputs the characteristic signal D4 to the storage unit 8a, and the storage unit 8a stores the data contained in the characteristic signal D4. The measurement unit 5b outputs the characteristic signal D4 to the storage unit 8b, and the storage unit 8b stores the data contained in the characteristic signal D4. Subsequently, the measurement unit 5a and the measurement unit 5b each output the characteristic signal D4 to the display 7.

[0025] Figures 3A and 3B are diagrams showing examples of screens displayed on the display according to the first embodiment. Figure 3A shows the frequency response characteristics during the first operation (translational movement). Figure 3B shows the frequency response characteristics during the second operation (rotational movement). Note that the graphs shown in Figures 3A and 3B are merely examples of frequency characteristics displayed on the display 7.

[0026] As shown in Figures 3A and 3B, when the display 7 receives the characteristic signal D4, it displays the frequency characteristics for the first operation (translational movement) and the frequency characteristics for the second operation (rotational movement). As shown in Figure 3B, resonance of approximately 30 Hz occurs only during the second operation. The reason why resonance occurs only during the second operation is that the vibrations excited differ depending on the direction of movement of the two axes. During translation, a mode in which the structure vibrates as a whole is excited, while during rotational movement, a mode in which the structure vibrates in a twisting manner is generated, and the frequencies of these modes are different.

[0027] As described above, the measuring units 5a and 5b measure the frequency response characteristics of the object 1 when it is moved in parallel and when it is moved in rotation. This makes it possible to recognize the difference in the frequency response characteristics of the object when it is moved in rotation and when it is moved in parallel. Therefore, by setting various control parameters according to that difference, the movement speed or positioning accuracy can be improved.

[0028] Figure 4 is a block diagram of a typical feedback control system for controlling speed. In typical feedback control, the difference signal between the measured speed and the target speed is amplified by the control unit C and input to the drive unit G, thereby improving responsiveness and accuracy. However, if the control unit C amplifies the signal too much, the controlled object will diverge and be destroyed. Therefore, there is a method to determine control parameters that allow the control system to be stably controlled using a loop transfer function F(s). The loop transfer function F(s) is expressed by the following equation.

[0029] F(s) = FG(s) * FC(s) * FH(s) The loop transfer function is expressed in the frequency domain, i.e., with frequency as the input variable. Here, FG(s) refers to the transfer characteristics of the drive unit G, FC(s) refers to the transfer characteristics of the control unit C, and FH(s) refers to the transfer characteristics of the detection unit H. s is the Laplace operator. The loop transfer function F(s) is the product of these.

[0030] In conventional feedback control, a sinusoidal speed command is input to the control unit C, and the speed measurement value of the drive unit G is measured by the detection unit H. From the speed command value (input) and the speed measurement value (output), the amplitude ratio and phase difference are calculated, and the control parameters are determined based on the calculation results. In this case, since there are countless drive patterns for the drive unit G, it is necessary to determine the frequency characteristics corresponding to each drive pattern, and measuring the frequency characteristics takes time.

[0031] In contrast, in this embodiment, a characteristic signal D4, which shows the frequency characteristics of the detection signal D2 (corresponding to the output) of the detection unit 3a and detection unit 3b (corresponding to detection unit H) in relation to the drive signal D1 (corresponding to the input) of the control unit 4a and control unit 4b (corresponding to control unit C), is measured in advance. Furthermore, the drive patterns (drive commands D3) of the drive unit 2a and drive unit 2b are limited to in-phase or out-of-phase. As a result, the measurement time for the frequency characteristics can be shortened.

[0032] (Modified Version) Figure 5 is an enlarged view of the area around the object in a measuring device according to a modified version of the first embodiment. The configuration of the measuring device according to this modified version is the same as that of the measuring device according to the first embodiment. In this modified version, unlike the first embodiment, the amplitude of the drive signal D1 (drive command D3) is different. In Figure 5, an XY Cartesian coordinate system is defined with the X axis parallel to the direction in which the two drive units 2a and 2b are arranged, and the Y axis perpendicular to the X axis. The drive unit 2b is positioned in the positive direction of the X axis as seen from the drive unit 2a. The object 1 is positioned across the main shafts 21a and 21b. More specifically, the object 1 is in contact with the main shaft 21a at a contact area 22a and with the main shaft 21b at a contact area 22b.

[0033] As shown in Figure 5, the drive unit 2a drives a motor built into the main spindle 21b to move the contact area 22a in the positive direction of the Y-axis. The drive unit 2b also drives a motor built into the main spindle 21b to move the contact area 22b in the negative direction of the Y-axis. For example, in the example in Figure 5, the amount of movement of the contact area 22b is half the amount of movement of the contact area 22a. The object 1 then rotates clockwise around a point P where the distance L1 from the drive unit 2a is twice the distance L2 from the drive unit 2b (hereinafter referred to as the "third operation"). The measuring units 5a and 5b measure the frequency response characteristics of the object 1 when the third operation is performed and store the measurement results in the storage unit.

[0034] As shown in this modified example, by making the amount of movement of the drive unit 2b and the drive unit 2a different, it is possible to change the center position during rotational movement. The amplitude of the drive signal D1 (drive command D3) can be set in any way.

[0035] In the example shown in Figure 5, it is also possible to set the movement of the contact area 22b to zero. In this case, only the drive unit 2a is driven, resulting in a so-called single-axis drive, and only the contact area 22a moves. At this time, the object 1 will rotate around the contact area 22b.

[0036] (Second Embodiment) Figure 6 is a schematic diagram showing the configuration of a measuring device according to the second embodiment. As shown in Figure 6, the measuring device according to this embodiment comprises an object 1 (system), drive units 2c to 2e, imaging units 3c and 3d, conversion unit 3e, control units 4c to 4e, measuring units 5c to 5e, command unit 6b, and storage units 8c to 8e. Each of the drive units 2c to 2e has a motor. Each of the drive units 2c to 2e is a form of drive mechanism. The drive unit 2c has a main shaft 21c. The drive unit 2d has a main shaft 21d. The drive unit 2e has a main shaft 21e. Each of the main shafts 21c to 21e is, for example, a ball screw. The imaging units 3c and 3d are each a form of detection unit. The measuring device according to this embodiment is configured as part of a positioning device that positions the object 1. The motor may also be a linear motor, including the drive units 2c to 2c and the main shafts 21c to 21e.

[0037] Object 1 is, for example, a stage on which workpieces such as electronic components are placed. Object 1 is marked with, for example, alignment marks P1. In Figure 6, mark P1 is shown as a circle, but it can be of any shape.

[0038] Object 1 is positioned in contact with the main spindles 21c to 21e. More specifically, object 1 is in contact with the main spindle 21c in contact region 22c, with the main spindle 21d in contact region 22d, and with the main spindle 21e in contact region 22e. The drive units 2c to 2e are the drive mechanism. Based on the drive signals D5 from the control units 4c to 4e, the drive units 2c to 2e move object 1 in a parallel or rotational manner. The operation of the drive units 2c to 2e will be described later.

[0039] Each of the imaging units 3c and 3d captures the mark P1 on the object 1 at a predetermined interval. Specifically, the imaging units 3c and 3d are positioned on the upper part of the object 1 and are set up so that the imaging direction faces the object 1. For example, as shown in Figure 6, if the object 1 has two marks P1, the imaging unit 3c captures one of the two marks P1 and the imaging unit 3d captures the other of the two marks P1. The imaging units 3c and 3d output the imaging results as image data D6 to the conversion unit 3e.

[0040] The conversion unit 3e generates the displacement (position) of the object 1 in the driving direction of the drive units 2c to 2e based on the image data D6. Specifically, the conversion unit 3e generates position information of the object 1 based on the image data D6, with respect to the mark P1 attached to the object 1. Then, the conversion unit 3e converts the position (coordinates) of the object 1 in the generated position information to the position (coordinates) of the object 1 in the driving direction of the drive units 2c to 2e. For example, in this embodiment, a first reference position (coordinate) in the position information corresponds to a second reference position (coordinate) in the driving direction of the drive units 2c to 2e. The conversion unit 3e converts the position of the object 1 in the position information, with respect to the first reference position, to the position of the object 1 in the driving direction of the drive units 2c to 2e, with respect to the second reference position. The conversion unit 3e outputs a detection signal D7, which is data indicating the conversion result, to the measurement units 5c to 5e.

[0041] The control units 4c to 4e generate a drive signal D5 based on the drive command D8 (described in detail later) output from the command unit 6b. For example, the control units 4c to 4e convert the received drive command D8 into data indicating the drive direction of the drive units 2c to 2e, and output the converted data as a drive signal D5 to the drive units 2c to 2e, respectively. The drive unit 2c drives the motor built into the spindle 21c based on the drive signal D5, moving the contact area 22c in a direction parallel to the X-axis. The drive unit 2d drives the motor built into the spindle 21d based on the drive signal D5, moving the contact area 22d in a direction parallel to the X-axis. The drive unit 2e drives the motor built into the spindle 21e based on the drive signal D5, moving the contact area 22e in a direction parallel to the Y-axis. Note that each of the control units 4c to 4e may be, for example, a servo amplifier.

[0042] Each of the measurement units 5c to 5e is, for example, a PC. Based on the detection signal D7 and the drive command D8, the measurement units 5c to 5e generate a characteristic signal D9 that shows the frequency response characteristics of the object 1, and output the generated characteristic signal D9 to the storage units 8c to 8e, respectively. The storage units 8c to 8e store the data for each characteristic signal D9. In this embodiment, as in the first embodiment, a display for displaying the characteristic signal D9 may be provided. Each of the measurement units 5c to 5e may be provided within the servo amplifier together with each of the control units 4c to 4e. In addition, each of the measurement units 5c to 5e may be configured using an external device such as an FFT analyzer, separate from each of the control units 4c to 4e. Furthermore, each of the measurement units 5c to 5e may be a PC, which may be a PC having a program or software for processing signals.

[0043] The command unit 6b outputs a drive command D8 indicating the drive pattern of the object 1. The drive command D8 is a sine wave or an M-sequence signal. The drive command D8 includes, for example, the drive direction of the drive units 2c to 2e and their amplitude as the drive pattern.

[0044] (Regarding the method for measuring frequency response characteristics) Each of FIGS. 7A to 7D is an enlarged view of the periphery of the object 1 in the measurement apparatus according to the second embodiment. As shown in FIGS. 7A to 7D, in the measurement apparatus according to the present embodiment, driving units 2c to 2e drive motors built into main shafts 21c to 21e, whereby the motors and the like built into the main shafts 21c to 21e operate respectively, causing the object 1 to translate in the X direction and the Y direction, and also perform rotational movement. Here, the object 1 is, for example, a rectangular stage having a horizontal length L and a vertical length H. At a reference position (broken line), a direction parallel to the horizontal length L of the object 1 is defined as an X-axis, and a direction parallel to the vertical length H is defined as a Y-axis. An XY coordinate system is defined with the lower left end of the object 1 (stage) at the reference position in FIG. 7A as an origin O (0, 0). The stage is not limited to a rectangular shape, and may be a square shape where L=H. In FIG. 7A, the driving unit 2c is provided at position Qc (L / 2, H), the driving unit 2d is provided at position Qd (0, H / 4), and the driving unit 2e is provided at position Qe (L, 3H / 4), respectively. The arrangement of the driving unit 2c, the driving unit 2d, and the driving unit 2e is the same also for FIGS. 7B to 7D. In the driving unit 2c, the main shaft 21c is parallel to the Y-axis and extends in the negative direction of the Y-axis. In the driving unit 2d, the main shaft 21d is parallel to the X-axis and extends in the positive direction of the X-axis. The main shaft 21e is parallel to the X-axis and extends in the negative direction of the X-axis.

[0045] More specifically, as shown in FIGS. 7A to 7D, the driving unit 2c moves the contact area 22c in a direction parallel to the Y-axis, thereby moving the object 1 in the direction parallel to the Y-axis. The driving unit 2d moves the contact area 22d in a direction parallel to the X-axis, thereby moving the object 1 in the direction parallel to the X-axis. The driving unit 2e moves the contact area 22e in a direction parallel to the X-axis, thereby moving the object 1 in the direction parallel to the X-axis.

[0046] In this embodiment, the command unit 6b generates a drive command D8 (drive pattern) such that the amount of movement (amplitude) of the drive units 2c to 2e in the drive direction is the same. Then, the control units 4c to 4e generate a drive signal D5 in accordance with the drive command D8 and output it to the drive units 2c to 2e, respectively. For example, as shown in Figure 7A, if the drive unit 2c moves the contact area 22c in the negative direction of the Y axis, the drive unit 2d moves the contact area 22d in the positive direction of the X axis, and the drive unit 2e moves the contact area 22e in the negative direction of the X axis, the object 1 rotates approximately clockwise (hereinafter referred to as the "fourth operation"). Furthermore, as shown in Figure 7B, if the drive unit 2c moves the contact area 22c in the negative direction of the Y-axis, the drive unit 2d moves the contact area 22d in the positive direction of the X-axis, and the drive unit 2e moves the contact area 22e in the positive direction of the X-axis, the object 1 will be translated in a downward direction to the right (hereinafter referred to as "the fifth operation"). Also, as shown in Figure 7C, if the drive unit 2c moves the contact area 22c in the negative direction of the Y-axis, the drive unit 2d moves the contact area 22d in the negative direction of the X-axis, and the drive unit 2e moves the contact area 22e in the negative direction of the X-axis, the object 1 will be translated in a downward direction to the left (hereinafter referred to as "the sixth operation"). Furthermore, as shown in Figure 7D, if the drive unit 2c moves the contact area 22c in the negative direction of the Y-axis, the drive unit 2d moves the contact area 22d in the negative direction of the X-axis, and the drive unit 2e moves the contact area 22e in the positive direction of the X-axis, the object 1 will rotate approximately counterclockwise (hereinafter referred to as "the seventh operation"). That is, in Figure 7A, both the drive unit 2d and the drive unit 2e are input with a drive signal D5 that is in phase with the drive signal D5 of the drive unit 2c. In Figure 7B, the drive unit 2d is input with a drive signal D5 that is in phase with the drive signal D5 of the drive unit 2c, and the drive unit 2e is input with a drive signal D5 that is in opposite phase with the drive signal D5 of the drive unit 2c. In Figure 7C, the drive unit 2d is input with a drive signal D5 that is in opposite phase with the drive signal D5 of the drive unit 2c, and the drive unit 2e is input with a drive signal D5 that is in phase with the drive signal D5 of the drive unit 2c. In Figure 7D, both drive unit 2d and drive unit 2e receive a drive signal D5 that is in the opposite phase to the drive signal D5 of drive unit 2c.

[0047] At this time, the control units 4c to 4e adjust the timing and output the drive signal D5 (in-phase or anti-phase) to the drive units 2c to 2e so that the drive signal D5 is simultaneously input to the drive units 2c to 2e. For this reason, the command unit 6b outputs a drive command D8 such that the drive signal D5 output from the control units 4c to 4e is simultaneously input to the drive units 2c to 2e.

[0048] Here, in the present embodiment, the measurement units 5c to 5e measure the frequency response characteristics of the object 1 when performing the fifth operation, the sixth operation (translational movement), the fourth operation, and the seventh operation (rotational movement). Specifically, the measurement units 5c to 5e generate a characteristic signal D9 indicating the frequency response characteristic of the object 1 based on the drive signal D5 (drive command D8) and the detection signal D7 when the fourth to seventh operations are performed, and store the characteristic signal D9 in the storage units 8c to 8e.

[0049] As described above, even when the object 1 is translationally and rotationally moved by the three drive directions (drive units 2c to 2e), the same effects as those of the first embodiment can be obtained.

[0050] (Modified Example) FIGS. 8A and 8B are enlarged views of the periphery of an object in a measurement apparatus according to a modified example of the second embodiment. The configuration of the measurement apparatus according to this modified example is the same as that of the measurement apparatus according to the first embodiment. In this modified example, unlike the second embodiment, the amplitude of the drive signal D5 (drive command D8) is different. Note that in FIGS. 8A and 8B, the definition of the XY orthogonal coordinate system and the arrangement of the drive units 2c to 2e are the same as those in the case of FIG. 7A.

[0051] As shown in FIG. 8A, the drive unit 2c moves the contact area 22c in the negative direction of the Y-axis, the drive unit 2d moves the contact area 22d in the positive direction of the X-axis, and the drive unit 2e moves the contact area 22e in the positive direction of the X-axis. For example, in the example of FIG. 8A, the movement amount of the drive unit 2c is approximately 10% of the movement amounts of the drive unit 2d and the drive unit 2e. Then, the object 1 moves in a slightly obliquely downward direction toward the right of the drawing (hereinafter referred to as "eighth operation").

[0052] As shown in Figure 8B, the drive unit 2c moves the contact area 22c in the negative direction of the Y-axis, the drive unit 2d moves the contact area 22d in the negative direction of the X-axis, and the drive unit 2e moves the contact area 22e in the negative direction of the X-axis. For example, in the example in Figure 8B, the amount of movement of the drive units 2d and 2e is about 10% of the amount of movement of the drive unit 2c. Then, the object 1 moves slightly to the left in the downward direction of the drawing (hereinafter referred to as "the ninth operation").

[0053] Each of the measurement units 5c to 5e measures the frequency response characteristics of the object 1 when the eighth and ninth operations are performed, and stores the measurement results in the storage unit.

[0054] As shown in this modified example, the amount of movement of the drive units 2c to 2e may be varied. For example, if it is known that in the object 1 there is a direction in which it is structurally prone to vibration due to parallel movement (a weaker structure), by adjusting the amount of movement (amplitude) of the drive units 2c to 2e and measuring the frequency response characteristics in the direction in which it is prone to vibration and the direction in which it is not, it becomes possible to measure the frequency response characteristics more appropriately.

[0055] (Other Embodiments) As described above, embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that are modified, replaced, added, or omitted as appropriate. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments.

[0056] In each of the above embodiments, the positioning device may be provided with a setting unit for setting the configuration of the drive unit. For example, the setting unit may include an input device for user operation. Specifically, the user may input the configuration of the drive unit (a configuration including two drive units for one drive direction, as in the first embodiment, or a configuration including three drive units for two drive directions, as in the second embodiment) via the input device.

[0057] The measuring device disclosed herein is useful because it can improve the positioning accuracy in a positioning device.

[0058] 1. Object (System) 2a-2e, G. Drive Unit 3a, 3b, H. Detection Unit 3c, 3d. Imaging Unit 4a-4e. Control Unit 5a-5e. Measurement Unit 6a, 6b. Command Unit 7. Display 8a-8e. Storage Unit 21a-21e. Main Axis 22a-22e. Contact Area P1. Mark D1, D5. Drive Signal D2, D7. Detection Signal D3, D8. Drive Command D4, D9. Characteristic Signal D6. Image Data

Claims

1. A measuring device for a system having a drive mechanism that moves an object in one direction using multiple drive units, comprising: a control unit that outputs multiple drive signals to control the multiple drive units, a detection unit that outputs a detection signal indicating the detection result of the drive state of the multiple drive units, and a measuring unit, wherein the multiple drive signals are in-phase or out-of-phase drive signals, and the measuring unit measures the frequency characteristics of the system in accordance with the multiple drive signals and the detection signal when the multiple drive signals are simultaneously input from the control unit to the multiple drive units.

2. The measuring device according to claim 1, wherein the plurality of drive signals are drive signals based on a plurality of drive patterns including in-phase, out-of-phase, and single-axis drive, and the measuring unit measures the frequency characteristics of the system for each of the plurality of drive signals based on the plurality of drive patterns.

3. The measuring device according to claim 1, further comprising a display unit for displaying the measurement results of the measuring unit.

4. The measuring device according to claim 2, wherein the plurality of drive signals output to each of the plurality of drive units are signals of the drive patterns, each having a different amplitude.

5. A measuring device further comprising a setting unit for setting the configuration of the drive mechanism.

Images