Parameter adjustment device, parameter adjustment method, and program

Abstract

A parameter adjustment device (2) adjusts control parameters in a servo system (1) comprising: a vibration detection unit (132) that detects vibrations generated in a drive unit (111) that changes the position of an object (4) and an imaging unit (12) that captures an image of the object (4); and a control unit (controller (14) and servo control device (15)) that controls the drive unit (111) on the basis of a set control parameter. The parameter adjustment device (2) comprises: a vibration determination unit (21) that acquires information indicating vibration detected by the vibration detection unit (132) and identifies the cause of the vibration on the basis of the acquired information; and a parameter adjustment unit (22) that adjusts, on the basis of the cause of the vibration identified by the vibration determination unit (21), the control parameter so as to suppress the vibration, and outputs the control parameter to the control unit.

Description

Parameter adjustment device, parameter adjustment method, and program

[0001] The present disclosure relates to a parameter adjustment device and the like.

[0002] Currently, technology for aligning the position of an object with a target position is often applied to production equipment driven by servo motors, and such production equipment is widely used in factories, etc. An effective method for realizing this technology is visual feedback (VFB) control, which periodically observes the movement of the object or servo motor in real time from the current position of the object using images captured by a visual sensor or the like, and changes commands to the motor of the production equipment according to the positional relationship with the target position.

[0003] In VFB control, in order to shorten the alignment time, which is the time it takes for an object to reach a target position, it is necessary to optimize the control parameters used in the VFB control and suppress vibrations occurring in the production equipment or the object. However, adjusting the control parameters to the optimum values ​​requires experience, and in particular, users with little experience in adjustment must spend a lot of time adjusting the control parameters. Therefore, in order to shorten the alignment time, a parameter adjustment device is known that automatically adjusts control parameters related to feedback control to reduce the amount of time required to adjust the control parameters (see, for example, Patent Document 1).

[0004] Patent No. 6922829

[0005] However, the parameter adjustment device described in Patent Document 1 may not adjust the control parameters that are the direct cause of vibrations occurring in the production equipment or the target object. Therefore, the parameter adjustment device may cause problems such as a long time required for automatic adjustment of the control parameters or a decrease in the accuracy of the adjusted control parameter values. Such a parameter adjustment device may cause a problem of being unable to adjust the control parameters effectively.

[0006] Therefore, an object of the present disclosure is to provide a parameter adjustment device and the like that can adjust control parameters more effectively.

[0007] In order to achieve the above goal, a parameter adjustment device according to one embodiment of the present disclosure is a parameter adjustment device for adjusting control parameters in a servo system including a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, and includes a vibration determination unit that acquires information indicating the vibration detected by the vibration detection unit and identifies the cause of the vibration based on the acquired information, and a parameter adjustment unit that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified by the vibration determination unit and outputs the control parameters to the control unit.

[0008] In order to achieve the above goal, a parameter adjustment method according to one embodiment of the present disclosure is a parameter adjustment method executed by a computer that adjusts control parameters in a servo system that includes a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, and includes a vibration determination step that acquires information indicating the vibration detected by the vibration detection unit and identifies the cause of the vibration based on the acquired information, and a parameter adjustment step that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified in the vibration determination step and outputs the control parameters to the control unit.

[0009] In order to achieve the above goal, a program according to one embodiment of the present disclosure causes the computer to execute the above parameter adjustment method.

[0010] The present disclosure provides a parameter adjustment device and the like that can adjust control parameters more effectively.

[0011] FIG. 1 is a block diagram showing the configuration of a system including a parameter adjustment device according to the present disclosure. FIG. 2 is a side view of the stage and imaging unit shown in FIG. 1. FIG. 3A is a diagram showing an example of movement of an object when a large velocity magnification is set in the calculation unit. FIG. 3B is a diagram showing an example of movement of an object when a small velocity magnification is set in the calculation unit. FIG. 4 is a flowchart showing a first operation example of the parameter adjustment device according to this embodiment. FIG. 5 is a diagram showing an ideal trajectory when a servo system moves an object to a target position. FIG. 6 is a diagram showing first waveform data and second waveform data generated by the vibration detection unit in step S14 of FIG. 4. FIG. 7 is a flowchart showing a second operation example of the parameter adjustment device according to this embodiment. FIG. 8 is a diagram showing changes in acceleration and jerk of an object over time before and after adjustment of the first control parameter. FIG. 9A is a diagram showing an example of an object when the servo system modulates the velocity magnification in the VFB region. FIG. 9B is an enlarged view of only the VFB phase shown in FIGS. 3A, 3B, and 9A. FIG. 10A is a diagram showing changes in trace speed over time. Fig. 10B is a diagram showing changes in tracing speed with respect to changes in excitation frequency. Fig. 11 is a diagram showing an example of an image displayed on the display unit by the parameter adjustment unit. Fig. 12 is a diagram showing examples of first waveform data and second waveform data acquired by the vibration determination unit of the parameter adjustment device. Fig. 13 is a diagram showing another example of the first waveform data and second waveform data generated by the vibration detection unit in step S14 of Fig. 4. Fig. 14 is a flowchart showing a modified example of operation example 1 of the parameter adjustment device according to this embodiment.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. The numerical values, components, component placement and connection configurations, steps, step order, display examples, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not recited in the independent claims of the present disclosure will be described as optional components. Furthermore, each figure is not necessarily an exact illustration. In each figure, substantially identical components are assigned the same reference numerals, and redundant explanations are omitted or simplified.

[0013] (Embodiment) [Configuration] Fig. 1 is a block diagram showing the configuration of a system including a parameter adjustment device 2 according to the present disclosure. The present disclosure is composed of a servo system 1, a parameter adjustment device 2, and a display unit 3. The servo system 1 and the parameter adjustment device 2, and the parameter adjustment device 2 and the display unit 3 are communicably connected to each other via a communication line. The communication realized by the communication line may be wired communication or wireless communication.

[0014] The servo system 1 is a device that moves an object to a target position, that is, positions (aligns) the object. For example, if the servo system 1 is a mounting device, the servo system 1 is a device that moves and mounts electronic components on a substrate (not shown).

[0015] In addition, the servo system 1 is a device that uses visual feedback (VFB) control to observe the movement of the object or the servo system 1 itself in real time using a visual sensor or the like, and reflects this in the next operation depending on the positional relationship with the target position.

[0016] 1, the servo system 1 includes a stage 11, an imaging unit 12, a terminal device 13, a controller 14, and a servo control device 15. The controller 14 and the servo control device 15 correspond to a control unit that controls the drive unit 111 based on set control parameters.

[0017] The stage 11 is a device that moves an object placed on a table 115 (described later) to a target position. The stage 11 includes a drive unit 111, a conversion mechanism 112, an encoder 113, a differentiator 114, and a table 115.

[0018] The driving unit 111 is, for example, a servo motor or an actuator that converts a voltage given from a control voltage generating unit 153 (described later) into rotation of a rotor.

[0019] The conversion mechanism 112 is a shaft that converts the rotation of the rotor into the movement of the table 115. The conversion mechanism 112 converts the rotation of a motor, for example, to move the table 115 in the X-axis, Y-axis, and Z-axis directions.

[0020] The encoder 113 calculates an encoder value from the displacement amount of the driving unit 111 and outputs the calculated encoder value to the differentiator 114. Furthermore, the encoder 113 generates encoder information indicating the calculated encoder value and outputs the generated encoder information to the vibration determination unit 21, which will be described later.

[0021] The differentiator 114 converts the encoder value output by the encoder 113 into the displacement amount per unit time of the table 115 (that is, the moving speed of the table 115) using Laplace transformation or the like, and outputs the converted value.

[0022] The table 115 is a platform on which an object is placed and a moving unit (head) that moves the object to a target position. The table 115 also has a marker such as a cross mark on the surface on which the object is placed.

[0023] The image capturing unit 12 is, for example, a visual sensor such as a camera, etc. The image capturing unit 12 periodically captures images of the table 115 and an object placed on the table 115 so as to include the above-mentioned markers.

[0024] The terminal device 13 is, for example, a personal computer or the like installed in a factory or the like. The terminal device 13 is a device that performs processing to calculate the position of a marker at the time of image capture from the image captured by the imaging unit 12. The terminal device 13 also includes an image processing unit 131 and a vibration detection unit 132. The image processing unit 131 and the vibration detection unit 132 are realized by a microcomputer, a processor, or the like. In other words, the functions of the image processing unit 131 and the vibration detection unit 132 are realized by the microcomputer, the processor, or the like executing a program stored in a memory.

[0025] The image processing unit 131 performs a process of calculating the position of the marker at the time of capturing an image from the image captured by the imaging unit 12. The image processing unit 131 further includes an image acquisition unit 1311 and a marker position detection unit 1312.

[0026] The image acquisition unit 1311 acquires the image captured by the imaging unit 12 .

[0027] The marker position detection unit 1312 detects the position of the marker at the time of image capture using the image acquired by the image acquisition unit 1311. The marker position detection unit 1312 detects the position of the marker, for example, using contour matching, which extracts a pattern having a contour that closely matches the contour of a pre-stored image. Furthermore, the marker position detection unit 1312 calculates the amount of movement of the marker position from the difference between the position of the marker at the time of the previous image capture and the position of the marker detected as described above. In other words, the marker position detection unit 1312 calculates the number of pixels by which the marker has moved in the image acquired by the image acquisition unit 1311.

[0028] The vibration detection unit 132 detects vibrations generated by the drive unit 111 and the image capture unit 12. Specifically, the vibration detection unit 132 acquires camera coordinate information indicating information on the image acquired by the image acquisition unit 1311 and information on changes in the position of the marker detected by the marker position detection unit 1312, and acquires encoder information output by the encoder 113. The vibration detection unit 132 also generates first waveform data indicating vibrations of the image capture unit 12 based on the acquired camera coordinate information, and generates second waveform data indicating vibrations of the drive unit 111 based on the acquired encoder information. The vibration detection unit 132 then outputs the generated first waveform data and second waveform data to the vibration determination unit 21, which will be described later. The vibration detection unit 132 acquires the camera coordinate information and the encoder information at regular intervals.

[0029] The controller 14 is a device that performs feedback control (first feedback loop) to move the position of the object imaged by the imaging unit 12 closer to a target position based on a first control parameter. Specifically, the controller 14 is a device that outputs a control signal to the servo control device 15 to move the position of the object imaged by the imaging unit 12 closer to the target position based on the first control parameter. The first control parameter is, for example, a position gain, a proportional gain, a differential gain, etc. The first feedback loop is a loop indicated by a dashed arrow.

[0030] The controller 14 includes a coordinate conversion unit 141, a difference calculator 142, a calculation unit 143, and a speed limiting unit 144. The coordinate conversion unit 141, the difference calculator 142, the calculation unit 143, and the speed limiting unit 144 are realized by a microcomputer, a processor, or the like. In other words, the functions of the coordinate conversion unit 141, the difference calculator 142, the calculation unit 143, and the speed limiting unit 144 are realized by the microcomputer, the processor, or the like executing a program stored in a memory.

[0031] The coordinate conversion unit 141 converts the number of pixels calculated by the marker position detection unit 1312 into the position of the object at the time of image capture. The coordinate conversion unit 141 converts the number of pixels into the position of the object using, for example, a transformation matrix.

[0032] The difference calculator 142 measures the difference (that is, the distance) between the position of the object at the time of image capture and the target position.

[0033] The calculation unit 143 calculates the rotational speed that the servo control device 15 should set in the drive unit 111 from the difference measured by the difference calculator 142 based on the set first control parameter. The rotational speed means, for example, the angle at which the rotor rotates per second. The calculation unit 143 calculates the rotational speed using proportional control (P control) and differential control (D control). In proportional control, the rotational speed is adjusted from the difference measured by the difference calculator 142 using a speed multiplier, which is a coefficient that converts the difference measured by the difference calculator 142 into a speed. In differential control, the rotational speed is adjusted so that the rotational speed is decelerated when the movement speed of the object, obtained by differentiating the difference between the position of the object at the time of image capture and the position of the previous object, exceeds a target movement speed, and is adjusted so that the rotational speed is accelerated when the movement speed is lower than the target movement speed. The calculation unit 143 sets the speed multiplier based on the first control parameter.

[0034] If the rotation speed calculated by the calculation unit 143 exceeds a predetermined upper limit, the speed limiting unit 144 outputs the upper limit as the target rotation speed (speed limit). Furthermore, if the acceleration required to reach the rotation speed calculated by the calculation unit 143 exceeds a predetermined upper limit, the speed limiting unit 144 sets the rotation speed reached at the acceleration of the upper limit as the target rotation speed (acceleration limit). The acceleration refers to, for example, the amount of speed change per 0.5 ms required to reach the target rotation speed from the current rotation speed. Furthermore, if neither of the above two cases applies, the speed limiting unit 144 sets the rotation speed calculated by the calculation unit 143 as the target rotation speed. The speed limiting unit 144 then outputs a signal related to the target rotation speed (i.e., a control signal) to the subtractor 152 (described later).

[0035] The servo control device 15 is a device that performs feedback control (second feedback loop) to bring the movement speed of the object closer to a target speed based on a second control parameter. Specifically, the servo control device 15 is a device that applies a voltage to the drive unit 111 to control the driving of the drive unit 111 to bring the movement speed of the object closer to the target speed based on the second control parameter. The second control parameter is, for example, a gain or frequency filter setting related to the control voltage of the drive unit 111. The second feedback loop is the loop indicated by the dotted arrow.

[0036] The servo control device 15 includes a speed measurement unit 151, a difference calculator 152, and a control voltage generation unit 153. The speed measurement unit 151, the difference calculator 152, and the control voltage generation unit 153 are realized by a microcomputer, a processor, or the like. That is, the functions of the speed measurement unit 151, the difference calculator 152, and the control voltage generation unit 153 are realized by the microcomputer, the processor, or the like executing a program stored in a memory.

[0037] The speed measurement unit 151 measures the rotation speed of the drive unit 111 from the displacement per unit time of the table 115 output by the differentiator 114 .

[0038] The difference calculator 152 measures the difference between the target rotation speed calculated by the speed limiting unit 144 and the rotation speed measured by the speed measuring unit 151 .

[0039] The control voltage generating unit 153 determines the voltage to be applied to the driving unit 111 from the difference measured by the differentiator 152 based on the set first control parameter, and outputs the determined voltage to the driving unit 111 .

[0040] The parameter adjustment device 2 is a device that adjusts in advance the control parameters (i.e., the first control parameter and the second control parameter) to be set in the control unit (the controller 14 and the servo control device 15). The parameter adjustment device 2 includes a vibration determination unit 21 and a parameter adjustment unit 22. The vibration determination unit 21 and the parameter adjustment unit 22 are realized by, for example, a microcomputer or a processor. In other words, the functions of the vibration determination unit 21 and the parameter adjustment unit 22 are realized by the microcomputer or the processor executing a program stored in a memory.

[0041] The vibration determination unit 21 acquires the first waveform data and the second waveform data output by the vibration detection unit 132, and determines, based on the acquired first waveform data and second waveform data, whether the cause of the vibration is in the imaging unit 12 or in the drive unit 111. Note that a detailed description of the operation of the vibration determination unit 21 to identify the cause of the vibration will be given later.

[0042] The parameter adjustment unit 22 adjusts the control parameters to suppress vibrations based on the cause of vibrations identified by the vibration determination unit 21, and outputs the adjusted control parameters to the control unit (i.e., the controller 14 and the servo control device 15). Specifically, when the cause of vibrations identified by the vibration determination unit 21 is the imaging unit 12, the parameter adjustment unit 22 adjusts the value of a first control parameter and outputs the adjusted first control parameter to the calculation unit 143 of the controller 14. When the cause of vibrations identified by the vibration determination unit 21 is the drive unit 111, the parameter adjustment unit 22 adjusts the value of a second control parameter and outputs the adjusted second control parameter to the control voltage generation unit 153 of the servo control device 15. The operation of the parameter adjustment unit 22 will be described in detail later.

[0043] Furthermore, the parameter adjustment unit 22 outputs data relating to the cause of the vibration and the adjusted control parameters to the display unit 3. Note that the data output by the parameter adjustment unit 22 may be either data relating to the cause of the vibration or data relating to the adjusted control parameters.

[0044] The display unit 3 displays the data and various information output by the parameter adjustment unit 22. The display unit 3 is realized by, for example, a liquid crystal display.

[0045] [Types of Vibration] Fig. 2 is a side view of the stage 11 and the imaging unit 12 shown in Fig. 1. Fig. 2 is a schematic diagram showing a state in which the object 4 is placed on the table 115 and the driving unit 111 is moving the object 4 to a target position. Note that the wavy lines shown in Fig. 2 are lines that indicate vibrations generated by driving the driving unit 111, and the arrows attached to the wavy lines are marks that indicate the direction in which the vibrations propagate.

[0046] 2, the stage 11 is placed on the work table 5. The stage 11 further includes a base plate 116, a vibration isolation table 117, a mounting table 118, and a fixture 119.

[0047] The base plate 116 is a platform within which the driving unit 111 can be driven.

[0048] The vibration isolation table 117 is a table that reduces vibrations generated by driving the driving unit 111 so that they are not transmitted to the work table 5 and the ground.

[0049] The installation table 118 is a table used to install the stage 11 on the work table 5 .

[0050] The fixture 119 is a jig for fixing the imaging unit 12 so that the imaging unit 12 can photograph the target object 4 from above.

[0051] Vibrations generated by driving the driving unit 111 propagate through the base plate 116, causing vibration A to be generated in the vibration isolation table 117. In the process of vibration A propagating through the fixing device 119 to the imaging unit 12, the fixing device 119 resonates with vibration A and generates vibration B. As a result, vibration A and vibration B are generated in the imaging unit 12. The above-mentioned first waveform data is data that shows vibration A and vibration B generated in the imaging unit 12 as waveforms.

[0052] Furthermore, the vibrations generated by driving the driving unit 111 propagate through the table 115, causing vibrations C to be generated in the object 4. The second waveform data described above is data that shows the vibrations C generated in the object 4 in the form of a waveform.

[0053] [Driving Example of Driver] Next, a driving example of the driver 111 will be described with reference to FIGS. 3A and 3B . FIG. 3A is a diagram showing an example of movement of the object 4 when the speed magnification set in the calculation unit 143 is large. FIG. 3B is a diagram showing an example of movement of the object 4 when the speed magnification set in the calculation unit 143 is small. The driver 111 drives the object 4, for example, to move as shown in FIG. 3A or 3B . The upper diagrams in FIGS. 3A and 3B are diagrams showing the positional change of the object 4 over time when the driver 111 moves the object 4 from the start position xi to the target position xf. The lower diagrams in FIGS. 3A and 3B are diagrams showing the moving speed of the object 4 over time when the driver 111 moves the object 4 from the start position xi to the target position xf. The lower diagrams in FIGS. 3A and 3B are graphs obtained by differentiating the position change with respect to the time change shown in the upper diagrams in FIGS. 3A and 3B.

[0054] As shown in the driving example of FIG. 3A , the driving unit 111 drives the object 4 in four phases: acceleration limit, speed limit, VFB, and stop processing. The acceleration limit phase is a phase in which the movement speed of the object 4 is accelerated within a range that does not exceed the upper limit value v1 set in the speed limiting unit 144 so as not to exceed the upper limit value of acceleration set in the speed limiting unit 144. The speed limit phase is a phase in which the object 4 is moved at the movement speed of the upper limit value v1 until the object 4 reaches the first threshold value. The VFB phase is a phase in which the movement speed of the object 4 is decelerated as the object 4 moves from the first threshold value to the second threshold value so that the object 4 can be stopped gently in the stop processing phase. In the VFB phase, the movement speed of the object 4 is determined using the speed multiplier described above. The stop processing phase is a phase in which the object 4 is stopped so as not to exceed the upper limit value of acceleration set in the speed limiting unit 144.

[0055] The first threshold and the second threshold are positions calculated from the start position xi and the target position xf. For example, the first threshold is a position whose distance from the target position xf is set to 1 / 3 of the distance between the start position xi and the target position xf. The second threshold is a position whose distance from the target position xf is set to 1 / 5 of the distance between the start position xi and the target position xf. The drive unit 111 drives the object 4 so that it stops at least within a range centered on the target position xf and extending above and below the difference between the second threshold and the target position xf.

[0056] During the acceleration restriction phase (time 0 to t1), the driver 111 moves the object 4 so that the acceleration does not exceed the upper limit value set in the speed restriction unit 144. Specifically, as shown in the lower diagram, the driver 111 accelerates the object 4 at a constant acceleration until the moving speed of the object 4 reaches the upper limit value v1. At this time, as shown in the upper diagram, the driver 111 moves the position of the object 4 from the start position xi to the position x1 so as to be expressed by a linear function.

[0057] Next, in the speed limit phase (time t1 to t2), the driving unit 111 moves the object 4 from position x1 to position x2 at a moving speed of upper limit value v1.

[0058] Next, in the VFB phase (time t2 to t3), the driving unit 111 decelerates the moving speed of the object 4 in a manner expressed by an exponential function until the object 4 moves from the first threshold value x2 to the second threshold value x3. At this time, as shown in the upper diagram, the driving unit 111 moves the position of the object 4 from the first threshold value x2 to the second threshold value x3 in a manner expressed by an exponential function.

[0059] Then, during the stop processing phase (time t3 to t4), the driver 111 stops the object 4 so as not to exceed the upper limit of acceleration set in the speed limiter 144. Specifically, as shown in the lower diagram, the driver 111 decelerates the object 4 at a constant acceleration until the object 4 stops. At this time, as shown in the upper diagram, the driver 111 moves the position of the object 4 from the second threshold value x3 to position x4 in a manner expressed by a quadratic function.

[0060] As shown in the driving example of FIG. 3B , the driving unit 111 drives the object 4 in three phases: acceleration limitation, VFB, and stop processing. The driving example of FIG. 3B differs from the driving example of FIG. 3A in that the speed limitation phase is omitted. This is because, in the VFB phase, the speed multiplier set in the case of FIG. 3B is smaller than the speed multiplier set in the case of FIG. 3A , so the movement speed of the object 4 from the first threshold value x2 to the second threshold value x3 is smaller. As a result, in the case of FIG. 3B , it takes longer and a longer distance for the object 4 to move from the first threshold value x2 to the second threshold value x3 than in the case of FIG. 3A . Therefore, in the driving example of FIG. 3B , the driving unit 111 performs driving without the speed limitation phase because it is necessary to transition to the VFB phase before the movement speed of the object 4 reaches the upper limit value v1 in the acceleration limitation phase.

[0061] 3A and 3B, the driving example in Fig. 3B has a smaller change in the moving speed of the object 4 in the VFB phase than the driving example in Fig. 3A, so the vibration generated in the VFB phase is smaller. Also, the driving example in Fig. 3B decelerates more slowly in the VFB phase than the driving example in Fig. 3A, so the time t4 required for the object 4 to completely stop is longer.

[0062] The parameter adjustment device 2 adjusts the first control parameter or the second control parameter so as to suppress vibrations occurring in the servo system 1 and shorten the time it takes for the object 4 to reach the target position xf. In other words, the parameter adjustment device 2 adjusts the first control parameter or the second control parameter so as to reduce vibrations occurring in the servo system 1 as in the driving example of Fig. 3B and shorten the time t4 required to reach the target position xf as in the driving example of Fig. 3A.

[0063] [Operation Example 1 of the Parameter Adjustment Device] Fig. 4 is a flowchart showing a first operation example of the parameter adjustment device 2 according to this embodiment. More specifically, Fig. 4 is a flowchart showing an operation example when the parameter adjustment device 2 adjusts control parameters after the servo system 1 has completed moving the object 4 to the target position (i.e., alignment). The operation example described in Fig. 4 is an operation example used when adjusting one control parameter set (i.e., a combination of a first control parameter and a second control parameter) for multiple operations of the driver 111. Note that the multiple operations of the driver 111 refer to multiple operating conditions with different combinations of the target value of the object 4, the upper limit of the rotational speed of the driver 111, the upper limit of the acceleration of the driver 111, etc.

[0064] First, the servo system 1 starts alignment by moving the object 4 to a target position (step S11), and then the servo system 1 completes the movement of the object 4 to the target position and completes the alignment (step S12).

[0065] Next, the vibration detection unit 132 acquires the camera coordinate information and the encoder information for the measurement time Ts, which includes the time when the alignment is completed (step S13). The measurement time Ts will be described in detail later.

[0066] Next, the vibration detection unit 132 generates first waveform data from the acquired camera coordinate information and second waveform data from the encoder information (step S14).

[0067] Next, the vibration determination unit 21 determines whether the first waveform data and the second waveform data generated by the vibration detection unit 132 in step S14 are both within the allowable range (step S15). The fact that the first waveform data and the second waveform data are both within the allowable range means that the values ​​included in the first waveform data and the values ​​included in the second waveform data are both within a determination threshold Dth, which will be described later.

[0068] If it is determined that both the first waveform data and the second waveform data are within the allowable range (Yes in step S15), the vibration determination unit 21 determines that there was no vibration during the alignment. In this case, the parameter adjustment unit 22 completes the adjustment of the control parameters without changing the values ​​of the first control parameter and the second control parameter (step S19).

[0069] If it is determined that at least one of the first waveform data and the second waveform data is not within the allowable range (No in step S15), the vibration determination unit 21 determines whether the second waveform data is within the allowable range (step S16). The second waveform data being within the allowable range means that the value included in the second waveform data is within a determination threshold Dth, which will be described later.

[0070] If it is determined that the second waveform data is within the acceptable range (Yes in step S16), the vibration determination unit 21 identifies that the cause of the vibration is the imaging unit 12, and the parameter adjustment unit 22 adjusts the value of the first control parameter (step S17).

[0071] After performing the process of step S17, the parameter adjusting unit 22 outputs the adjusted first control parameter to the controller 14, thereby completing the adjustment of the control parameter (step S19).

[0072] If it is determined that the second waveform data is not within the allowable range (No in step S16), the vibration determination unit 21 identifies that the cause of the vibration is the drive unit 111, and the parameter adjustment unit 22 adjusts the value of the second control parameter (step S18).

[0073] After performing the process of step S18, the parameter adjusting section 22 outputs the adjusted second control parameter to the servo control device 15, thereby completing the adjustment of the control parameter (step S19).

[0074] The measurement time Ts in step S13 in Fig. 4 will be described with reference to Fig. 5. Fig. 5 is a diagram showing an ideal trajectory when the servo system 1 moves the object 4 to a target position. The ideal trajectory is an ideal waveform calculated by the parameter adjustment device 2 through simulation.

[0075] FIG. 5A is a diagram showing the difference from the target position over time. In the graph shown in FIG. 5A, the horizontal axis represents time, and the vertical axis represents the difference between the current position of the object and the target position (i.e., the encoder value or camera coordinates). In other words, FIG. 5A is a diagram showing the ideal waveform of the first waveform data or the second waveform data. FIG. 5B is an enlarged view of the area surrounded by the dashed line in FIG. 5A. FIG. 5B is a diagram showing the time before and after the completion time of alignment performed by the servo system 1. Note that the alignment completion time shown in FIG. 5B is the time when the servo system 1 completes moving the object 4 to the target position on the ideal trajectory.

[0076] The ideal locus shown in FIG. 5(a) is a waveform obtained when the servo system 1 moves the object 4 to a target position without vibrating.

[0077] As shown in (b) of Figure 5, a grayscale area is added. The horizontal width of the area is represented by a measurement time Ts centered on the alignment completion time. The measurement time Ts is set to, for example, 5 ms. The vertical width of the area is represented by a judgment threshold Dth centered on the value of the ideal trajectory at each time within the measurement time Ts. The value set for the judgment threshold Dth is, for example, 0.1 mm. The vibration judgment unit 21 judges whether the values ​​included in the first waveform data and the second waveform data at each time within the measurement time Ts are each within the judgment threshold Dth.

[0078] Fig. 6 is a diagram showing the first waveform data and the second waveform data generated by the vibration detection unit 132 in step S14 of Fig. 4. In Fig. 6, the first waveform data is represented by a dotted line, and the second waveform data is represented by a dashed line.

[0079] 6A shows a case where the values ​​included in the first waveform data and the values ​​included in the second waveform data are both within the judgment threshold Dth at each time within the measurement time Ts. FIG. 6B shows a case where the values ​​included in the first waveform data exceed the judgment threshold Dth and the values ​​included in the second waveform data are within the judgment threshold Dth at each time within the measurement time Ts. FIG. 6C shows a case where the values ​​included in the first waveform data and the values ​​included in the second waveform data are both above the judgment threshold Dth at each time within the measurement time Ts.

[0080] 6A, the vibration determination unit 21 determines that both the first waveform data and the second waveform data are within the allowable range. In such a case, the vibration determination unit 21 determines that there was no vibration in the alignment, and the parameter adjustment unit 22 completes the adjustment of the control parameters without changing the values ​​of the first control parameter and the second control parameter.

[0081] 6B, the vibration determination unit 21 determines that the first waveform data is not within the allowable range and that the second waveform data is within the allowable range. In such a case, the vibration determination unit 21 identifies that the cause of the vibration is the imaging unit 12, and the parameter adjustment unit 22 adjusts the value of the first control parameter.

[0082] 6(c), the vibration determination unit 21 determines that both the first waveform data and the second waveform data are not within the allowable range. In such a case, the vibration determination unit 21 identifies that the cause of the vibration is the driver 111, and the parameter adjustment unit 22 adjusts the value of the second control parameter.

[0083] From the above explanation, if the parameter adjustment device 2 determines that the cause of the vibration is the imaging unit 12, it adjusts the value of the first control parameter, and if it determines that the cause of the vibration is the drive unit 111, it adjusts the value of the second control parameter, so that the vibration of the imaging unit 12 and the vibration of the drive unit 111 are distinguished from each other and the vibration is appropriately suppressed.

[0084] [Operation Example 2 of the Parameter Adjustment Device] Fig. 7 is a flowchart showing a second operation example of the parameter adjustment device 2 according to this embodiment. More specifically, Fig. 7 is a flowchart showing an operation example in which the parameter adjustment device 2 adjusts control parameters as needed (i.e., in real time) while the servo system 1 is moving the object 4 to a target position (i.e., during alignment). The operation example described in Fig. 7 is an operation example used when adjusting one control parameter set (i.e., a combination of a first control parameter and a second control parameter) when there is a phase transition described in Figs. 3A and 3B.

[0085] First, the servo system 1 starts alignment to move the object 4 to a target position (step S21).

[0086] Next, the vibration detection unit 132 acquires camera coordinate information and encoder information during the alignment operation (step S22).

[0087] Next, the vibration detection unit 132 generates first waveform data from the acquired camera coordinate information and second waveform data from the encoder information (step S23).

[0088] Next, the vibration determination unit 21 determines whether the first waveform data and the second waveform data generated by the vibration detection unit 132 in step S23 are both within an allowable range (step S24).

[0089] If it is determined that both the first waveform data and the second waveform data are within the allowable range (i.e., waveform data such as that shown in FIG. 6A has been acquired) (Yes in step S24), the vibration determination unit 21 determines that there was no vibration during the alignment. In this case, the parameter adjustment unit 22 does not change the values ​​of the first control parameter and the second control parameter.

[0090] If it is determined that at least one of the first waveform data and the second waveform data is not within the allowable range (i.e., waveform data such as (b) of Figure 6 or (c) of Figure 6 has been acquired) (No in step S24), the vibration determination unit 21 determines whether the second waveform data is within the allowable range (step S25).

[0091] If it is determined that the second waveform data is within the allowable range (i.e., waveform data such as that shown in FIG. 6B has been acquired) (Yes in step S25), the vibration determination unit 21 determines that the cause of the vibration is the imaging unit 12, and the parameter adjustment unit 22 adjusts the value of the first control parameter (step S26). Then, the parameter adjustment unit 22 outputs the adjusted first control parameter to the controller 14.

[0092] If it is determined that the second waveform data is not within the allowable range (i.e., waveform data such as that shown in FIG. 6C has been acquired) (No in step S25), the vibration determination unit 21 determines that the cause of the vibration is the driver 111, and the parameter adjustment unit 22 adjusts the value of the second control parameter (step S27). Then, the parameter adjustment unit 22 outputs the adjusted second control parameter to the servo control device 15.

[0093] After the process performed after Yes in step S24, or after the process in step S26 or step S27, the parameter adjusting unit 22 determines whether alignment is complete (step S28).

[0094] If it is determined that the alignment is not complete (No in step S28), the vibration detection unit 132 performs the process of step S22 again.

[0095] If it is determined that the alignment is complete (Yes in step S28), the servo system 1 completes the alignment (step S29).

[0096] It should be noted that the determinations in steps S24 and S25 in Fig. 7 differ in the way the grayscale area is set from that described in Fig. 5B. The way the grayscale area is set will be described below.

[0097] The horizontal width of the region is represented by a measurement time Ts centered on the time when the camera coordinate information or encoder information was acquired, and the vertical width of the region is a determination threshold Dth centered on the value of the ideal trajectory at each time within the measurement time Ts.

[0098] 7, the parameter adjusting unit 22 may adjust the first control parameter so as to reduce the amount of change in acceleration and the amount of change in jerk that occur due to the phase transitions shown in FIGS. 3A and 3B. The changes in acceleration and jerk of the object 4 with respect to time before and after the adjustment of the first control parameter will be described with reference to FIG. 8. Note that the jerk is the rate of change in acceleration per unit time.

[0099] 8A and 8B are diagrams showing changes in acceleration and jerk of the object 4 over time before and after adjustment of the first control parameter. (a) of FIG. 8A is a diagram showing changes in acceleration and jerk of the object 4 over time before adjustment of the first control parameter. (a) of FIG. 8A is a diagram showing changes in acceleration and jerk of the object 4 over time in the area surrounded by a dashed line in the lower diagram of FIG. 3A. (b) of FIG. 8A is a diagram showing changes in acceleration and jerk of the object 4 over time after adjustment of the first control parameter. The upper diagrams of FIGS. 8A and 8B are diagrams showing changes in acceleration of the object 4 over time, and the lower diagrams of FIGS. 8A and 8B are diagrams showing changes in jerk of the object 4 over time.

[0100] As shown in the upper diagram of Fig. 8(a), before the adjustment of the first control parameter, the acceleration changes suddenly at the transition from the acceleration limit phase to the speed limit phase (time t1). As a result, as shown in the lower diagram of Fig. 8(a), the jerk changes significantly near the transition from the acceleration limit phase to the speed limit phase. This large change in jerk causes vibrations in the table 115 and the object 4, and the value of the first waveform data obtained based on the camera coordinate information exceeds the determination threshold Dth.

[0101] Therefore, as shown in the upper diagram of Fig. 8(b), the parameter adjusting unit 22 adjusts the first control parameter so that the acceleration changes gradually. As a result, as shown in the lower diagram of Fig. 8(b), the change in jerk becomes smaller near the transition from the acceleration limit phase to the speed limit phase. This makes it less likely that vibration will occur in the table 115 and the object 4, and the value of the first waveform data obtained based on the camera coordinate information will be within the determination threshold Dth.

[0102] As explained above, the parameter adjustment device 2 targets a servo system that performs two types of feedback control and adjusts the value of either the first control parameter or the second control parameter based on the cause of vibration, thereby accurately suppressing vibration in the servo system 1 that performs two types of feedback control.

[0103] [Modification of Parameter Adjustment Device] In the driving example of the driver 111 shown in FIGS. 3A and 3B , the calculation unit 143 uses a single speed multiplier in the VFB phase. This may make it difficult for the parameter adjustment device 2 to adjust the first or second control parameter so that the vibration generated in the servo system 1 is reduced and the time t4 to reach the target position xf is shortened. Specifically, as shown in FIG. 3A , when the moving speed of the object 4 changes suddenly, the time t4 to reach the target position xf can be shortened, but the value of jerk increases, which tends to increase the vibration generated in the servo system 1. On the other hand, as shown in FIG. 3B , when the moving speed of the object 4 changes slowly, the vibration generated in the servo system 1 can be reduced, but the time t4 to reach the target position xf tends to be longer. In other words, when the calculation unit 143 uses a single speed multiplier in the VFB phase, it may be difficult for the parameter adjustment device 2 to adjust the control parameter that can optimize two conflicting performances.

[0104] Therefore, the parameter adjustment device 2 may adjust the value of the first control parameter during the VFB phase and output the adjusted first control parameter to the controller 14, thereby allowing the calculation unit 143 to have a function of modulating the speed magnification. Specifically, when the jerk during the VFB phase is no longer within a preset range, the parameter adjustment unit 22 adjusts the value of the first control parameter so that the calculation unit 143 modulates the value to a speed magnification that results in a jerk that falls within the range.

[0105] 4, the parameter adjusting unit 22 may adjust two or more first control parameters so that the first control parameters are switched in the VFB phase, and output the adjusted first control parameters to the controller 14. This adjustment enables the driving unit 111 to move the object 4 at movement speeds represented by two or more different exponential functions in the VFB phase of all operations.

[0106] 7, the parameter adjusting unit 22 may adjust the first control parameter so that the first control parameter is switched in the VFB phase, and output the adjusted first control parameter to the controller 14. In other words, the parameter adjusting unit 22 can adjust the first control parameter even in the VFB phase.

[0107] An example of driving the driver 111 showing modulation of the velocity magnification in the VFB phase will be described with reference to FIG. 9A . FIG. 9A is a diagram showing an example of the object 4 when the servo system 1 modulates the velocity magnification in the VFB region. FIG. 9A is a diagram showing that when the position of the object 4 is x5 and the moving velocity of the object 4 is v5, the jerk of the object 4 becomes a value outside the preset range. That is, FIG. 9A is a diagram showing that the parameter adjustment device 2 adjusts the first control parameter when the position of the object 4 is x5 and the moving velocity of the object 4 is v5. The upper diagram in FIG. 9A is a diagram showing the position change of the object 4 over time when the driver 111 moves the object 4 from the start position xi to the target position xf. The lower diagram in FIG. 9A is a diagram showing the moving velocity of the object 4 over time when the driver 111 moves the object 4 from the start position xi to the target position xf. The lower diagram in FIG. 9A is a graph obtained by differentiating the position change with respect to the time change shown in the upper diagram in FIG. 9A.

[0108] 9A , in the VFB phase, the movement speed of the object 4 is high when the object 4 is located between positions x2 and x5, and the movement speed of the object 4 is low when the object 4 is located between positions x5 and x3. In other words, in the VFB phase, when the object 4 is located between positions x2 and x5, the calculation unit 143 sets the speed multiplier to be high, and when the object 4 is located between positions x5 and x3, the calculation unit 143 sets the speed multiplier to be low.

[0109] Next, a comparison of driving examples of the driver 111 in the VFB phase will be described. Fig. 9B is an enlarged view of only the VFB phase shown in Figs. 3A, 3B, and 9A. Note that Fig. 9B aligns the start time t2 of the VFB phase in each of the figures. The upper diagram in Fig. 9B shows the positional change of the object 4 over time when the driver 111 moves the object 4 from the first threshold value x2 to the second threshold value x3. The lower diagram in Fig. 9B shows the moving speed of the object 4 over time when the driver 111 moves the object 4 from the first threshold value x2 to the second threshold value x3.

[0110] In Fig. 9B, the solid lines indicate the phases of VFB shown in Fig. 3A, the dashed lines indicate the phases of VFB shown in Fig. 3B, and the dashed lines indicate the phases of VFB shown in Fig. 9A. In addition, the wavy lines superimposed on each line indicate the magnitude of vibration generated in the servo system 1.

[0111] 9B , in the servo system 1, by modulating the speed multiplier by the calculator 143, the time t3 until the VFB phase is completed can be shortened compared to when the calculator 143 sets a constant, small speed multiplier (i.e., the dashed line), and therefore the arrival time t4 to the target position xf can also be shortened. Also, by modulating the speed multiplier by the calculator 143, the servo system 1 can reduce vibrations generated in the servo system 1 during the VFB phase compared to when the calculator 143 sets a constant, large speed multiplier (i.e., the solid line).

[0112] In the description of FIGS. 9A and 9B , the parameter adjustment unit 22 may output multiple first control parameters to the controller 14 when the jerk becomes a value outside the preset range multiple times, or may output the first control parameter to the controller 14 every time the jerk becomes a value outside the preset range.

[0113] As explained above, the parameter adjustment device 2 adjusts the first control parameter, and the calculation unit 143 modulates the value of the speed multiplication factor, thereby making it possible to reduce the vibration generated in the servo system 1 and shorten the time t4 required to reach the target position xf.

[0114] [Control Verification] The camera coordinate information described above includes trace data indicating changes in marker position over time. The encoder information also includes trace data indicating changes in the position of the table 115 over time. The information obtained from the two trace data will be described below with reference to FIG. 10A.

[0115] Fig. 10A is a diagram showing changes in tracing speed over time. (a) of Fig. 10A is a diagram showing tracing data included in camera coordinate information. (b) of Fig. 10A is a diagram showing tracing data included in encoder information. Note that the solid lines shown in (a) of Fig. 10A and (b) of Fig. 10A are lines showing changes in tracing speed over time when intentional vibration is applied to the imaging unit 12, and the dashed lines shown in (a) of Fig. 10A and (b) of Fig. 10A are lines showing changes in tracing speed over time when no vibration is applied to the imaging unit 12.

[0116] 10A(a), it can be seen that the rate of increase in the tracing speed of the imaging unit 12 when vibration is intentionally applied to the imaging unit 12 is smaller than the rate of increase in the tracing speed of the imaging unit 12 when vibration is not applied to the imaging unit 12. From this, it can be seen that the servo system 1 controls the driving of the drive unit 111 so as to reduce the rate of increase in the tracing speed of the imaging unit 12 and suppress the vibration generated in the imaging unit 12 when vibration is intentionally applied to the imaging unit 12.

[0117] 10A(b), it can be seen that the rate of increase in the tracing speed of the encoder 113 when vibration is intentionally applied to the imaging unit 12 is almost the same as the rate of increase in the tracing speed of the encoder 113 when no vibration is applied to the imaging unit 12. From this, it can be seen that when vibration is intentionally applied to the imaging unit 12, the servo system 1 controls the driving of the drive unit 111 without changing the rate of increase in the tracing speed of the encoder 113.

[0118] 10A(a) and 10A(b), it can be confirmed that the parameter adjustment device 2 is adjusting only the first control parameter output to the controller 14. This makes it possible to confirm that control is being performed using the control parameter adjustment method according to the present disclosure.

[0119] Furthermore, the camera coordinate information includes trace data indicating changes in marker position relative to frequency changes, and the encoder information includes trace data indicating changes in the position of table 115 relative to frequency changes. Information obtained from the two trace data will be described below with reference to FIG. 10B.

[0120] Fig. 10B is a diagram showing changes in the tracing speed with respect to changes in the excitation frequency. Fig. 10B (a) is a diagram showing trace data included in the camera coordinate information. Fig. 10B (b) is a diagram showing trace data included in the encoder information. The excitation frequency is the frequency of vibration generated by a force applied to the imaging unit 12 from outside (for example, a vibration exciter attached to the fixture 119).

[0121] 10B(a), it can be seen that the tracing speed decreases as the vibration frequency increases. From this, it can be seen that when vibration is intentionally applied to the imaging unit 12, the servo system 1 controls the driving of the driving unit 111 so as to reduce the tracing speed of the imaging unit 12 and suppress the vibration generated in the imaging unit 12.

[0122] 10B(b), it can be seen that the tracing speed is constant regardless of the vibration frequency. From this, it can be seen that when vibration is intentionally applied to the imaging unit 12, the servo system 1 controls the driving of the driving unit 111 without changing the tracing speed of the encoder 113.

[0123] 10B(a) and 10B(b), it can be confirmed that the parameter adjustment device 2 is adjusting only the first control parameter output to the controller 14. This makes it possible to confirm that control is being performed using the control parameter adjustment method according to the present disclosure.

[0124] [Display Image] Next, an example of an image that the parameter adjustment unit 22 displays on the display unit 3 will be described with reference to Fig. 11. Fig. 11 is a diagram showing an example of an image that the parameter adjustment unit 22 displays on the display unit 3.

[0125] 11 , the image includes a trace data display area 31, a vibration cause display area 32, and a control parameter display area 33. Note that the image may be an image in which at least one of the vibration cause display area 32 and the control parameter display area 33 is displayed.

[0126] The trace data display area 31 is an area where a diagram showing the trace data described in Figures 10A and 10B is displayed. Note that in Figure 11, a diagram showing the two pieces of trace data described in Figure 10A is displayed in the trace data display area 31, but this is not limiting. Specifically, a diagram showing the two pieces of trace data described in Figure 10B may be displayed in the trace data display area 31, or a diagram showing the four pieces of trace data described in Figures 10A and 10B may be displayed in the trace data display area 31.

[0127] The vibration cause display area 32 is an area where the cause of vibration identified by the vibration determination unit 21 is displayed.

[0128] The control parameter display area 33 is an area where the values ​​of the control parameters before and after adjustment by the parameter adjustment unit 22 are displayed. For example, as shown in Fig. 11 , a table showing the values ​​of control parameter a set in the controller 14 before and after adjustment, and a table showing the values ​​of control parameter b set in the servo control device 15 before and after adjustment are displayed in the control parameter display area 33. Note that each of the two tables displayed in the control parameter display area 33 may display a plurality of control parameters.

[0129] As explained above, the parameter adjustment device 2 displays the data on the display unit 3, allowing the user to confirm at least one of the cause of the vibration and the result of the adjustment of the control parameters.

[0130] [Other Modifications of the Parameter Adjustment Node] Other modifications of the parameter adjustment node 2 will be described below.

[0131] [Regarding the Time Delay of the First Waveform Data and the Second Waveform Data] In the above description, the vibration determination unit 21 of the parameter adjustment device 2 identifies the cause of vibration without considering the time delay of the acquired first waveform data and the time delay of the second waveform data. However, the vibration determination unit 21 of the parameter adjustment device 2 may identify the cause of vibration after aligning the time axes of the first waveform data and the second waveform data. FIG. 12 is a diagram showing an example of the first waveform data and the second waveform data acquired by the vibration determination unit 21 of the parameter adjustment device 2. (a) of FIG. 12 is a diagram showing an example of waveform data when the vibration determination unit 21 of the parameter adjustment device 2 identifies the cause of vibration without considering the time delay of the first waveform data and the time delay of the second waveform data. (b) of FIG. 12 is a diagram showing an example of waveform data when the vibration determination unit 21 of the parameter adjustment device 2 identifies the cause of vibration while considering the time delay of the first waveform data and the time delay of the second waveform data.

[0132] As shown in (a) of Figure 12, the vibration determination unit 21 may identify the cause of vibration without taking into account the time delay when acquiring the first waveform data (hereinafter also referred to as camera delay) and the time delay when acquiring the second waveform data (hereinafter also referred to as encoder delay).

[0133] 12(b), the vibration determination unit 21 may offset the first waveform data and the second waveform data by a predetermined value to align the time axes in consideration of camera delay and encoder delay, and then identify the cause of vibration. In other words, the vibration determination unit 21 may identify the cause of vibration after adjusting the phase shift between the first waveform data and the second waveform data. This allows the parameter adjustment device 2 to identify the cause of vibration based on the first waveform data and the second waveform data in the same time period.

[0134] In addition, the vibration determination unit 21 of the parameter adjustment device 2 may acquire the first waveform data and the second waveform data for at least one cycle, and identify the cause of the vibration by comparing the amplitude of the acquired first waveform data and the amplitude of the acquired second waveform data with the determination threshold Dth.

[0135] [Regarding Identifying the Cause of Vibration] In the description of Fig. 6, the vibration determination unit 21 of the parameter adjustment device 2 made three determinations based on the acquired first waveform data and second waveform data, but more detailed determinations may also be made. Fig. 13 is a diagram showing another example of the first waveform data and second waveform data generated by the vibration detection unit 132 in step S14 of Fig. 4. Note that in Fig. 13, the first waveform data is represented by a dotted line, and the second waveform data is represented by a dashed line.

[0136] 13A shows a case where the values ​​included in the first waveform data and the values ​​included in the second waveform data are both within the judgment threshold Dth at each time within the measurement time Ts. FIG. 13B shows a case where the values ​​included in the first waveform data exceed the judgment threshold Dth and the values ​​included in the second waveform data are within the judgment threshold Dth at each time within the measurement time Ts. FIG. 13C shows a case where the values ​​included in the first waveform data are within the judgment threshold Dth and the values ​​included in the second waveform data exceed the judgment threshold Dth at each time within the measurement time Ts. FIG. 13D shows a case where the values ​​included in the first waveform data and the values ​​included in the second waveform data are both above the judgment threshold Dth at each time within the measurement time Ts.

[0137] 13A, the vibration determination unit 21 determines that both the first waveform data and the second waveform data are within the allowable range. In such a case, the vibration determination unit 21 determines that there was no vibration in the alignment, and the parameter adjustment unit 22 completes the adjustment of the control parameters without changing the values ​​of the first control parameter and the second control parameter.

[0138] 13(b), the vibration determination unit 21 determines that the first waveform data is not within the allowable range and that the second waveform data is within the allowable range. In such a case, the vibration determination unit 21 identifies that the cause of the vibration is the imaging unit 12, and the parameter adjustment unit 22 adjusts the value of the first control parameter.

[0139] 13(c), the vibration determination unit 21 determines that the first waveform data is within the allowable range and the second waveform data is not within the allowable range. In such a case, the vibration determination unit 21 identifies that the cause of the vibration is the driver 111, and the parameter adjustment unit 22 adjusts the value of the second control parameter.

[0140] 13(d), the vibration determination unit 21 determines that both the first waveform data and the second waveform data are not within the allowable range. In such a case, the vibration determination unit 21 identifies that the cause of the vibration is the imaging unit 12 and the drive unit 111, and the parameter adjustment unit 22 adjusts the values ​​of the first control parameter and the second control parameter.

[0141] As explained above, the parameter adjustment device 2 adjusts the control parameters based on the cause of the vibration, and therefore the vibration can be suppressed appropriately.

[0142] [Modification of Operational Example 1 of the Parameter Adjustment Node] The following describes a modification of Operational Example 1 of the parameter adjustment node 2. Fig. 14 is a flowchart showing a modification of Operational Example 1 of the parameter adjustment node 2 according to this embodiment.

[0143] First, the servo system 1 starts alignment by moving the object 4 to a target position (step S101), and then the servo system 1 completes the movement of the object 4 to the target position and completes the alignment (step S102).

[0144] The vibration detection unit 132 acquires camera coordinate information and encoder information at a measurement time Ts that includes the alignment completion time (step S103).

[0145] The vibration detection unit 132 generates first waveform data from the acquired camera coordinate information and second waveform data from the encoder information, and the vibration determination unit 21 adjusts the phase difference between the acquired first waveform data and second waveform data (step S104). The vibration determination unit 21 performs FFT analysis on the first waveform data and second waveform data (step S105). Specifically, the vibration determination unit 21 converts the first waveform data and second waveform data, whose horizontal axis is represented as a time axis, into data whose horizontal axis is represented as a frequency axis.

[0146] The vibration determination unit 21 determines whether the first waveform data and the second waveform data subjected to the FFT analysis are both within the allowable range (step S106).

[0147] If the vibration determination unit 21 determines that both the first waveform data and the second waveform data are within the allowable range (Yes in step S106), it determines that there was no vibration in the alignment. In this case, the parameter adjustment unit 22 completes the adjustment of the control parameters without changing the values ​​of the first control parameter and the second control parameter (step S112). Specifically, if the vibration determination unit 21 has acquired the first waveform data and the second waveform data shown in (a) of FIG. 13, the parameter adjustment unit 22 completes the adjustment of the control parameters without changing the values ​​of the first control parameter and the second control parameter.

[0148] If the vibration determination unit 21 determines that at least one of the first waveform data and the second waveform data is not within the allowable range (No in step S106), it determines whether the first waveform data is within the allowable range (step S107).

[0149] If the vibration determination unit 21 determines that the first waveform data is within the allowable range (Yes in step S107), it identifies that the cause of the vibration is the driver 111, and the parameter adjustment unit 22 adjusts the value of the second control parameter (step S108). Specifically, if the vibration determination unit 21 has acquired the first waveform data and the second waveform data as shown in (c) of Fig. 13, the parameter adjustment unit 22 adjusts the value of the second control parameter.

[0150] When it is determined that the first waveform data is not within the allowable range (No in step S107), the vibration determination unit 21 determines whether the second waveform data is within the allowable range (step S109).

[0151] If the vibration determination unit 21 determines that the second waveform data is within the allowable range (Yes in step S109), it identifies that the cause of the vibration is the image capture unit 12, and the parameter adjustment unit 22 adjusts the value of the first control parameter (step S110). Specifically, if the vibration determination unit 21 has acquired the first waveform data and the second waveform data as shown in (b) of Fig. 13, the parameter adjustment unit 22 adjusts the value of the first control parameter.

[0152] If the vibration determination unit 21 determines that the second waveform data is not within the allowable range (No in step S109), it identifies that the cause of the vibration is both the imaging unit 12 and the drive unit 111, and the parameter adjustment unit 22 adjusts the values ​​of the first control parameter and the second control parameter (step S111). Specifically, if the vibration determination unit 21 has acquired the first waveform data and the second waveform data as shown in (d) of Fig. 13, the parameter adjustment unit 22 adjusts the values ​​of the first control parameter and the second control parameter.

[0153] In step S111, when adjusting the value of the first control parameter and the value of the second control parameter, the parameter adjustment unit 22 determines the adjustment ratio of the first control parameter and the second control parameter based on the following equation 1, and specifies the value of the control parameter.

[0154] (Value of control parameter)=(Value of first control parameter)×P1+(Value of second control parameter)×(100−P1) (Equation 1)

[0155] For example, when focusing on the frequency of vibration, the parameter adjustment unit 22 may determine the adjustment ratios of the first control parameter and the second control parameter based on the ratio of vibration due to low-frequency components to vibration due to high-frequency components. Specifically, when the ratio of vibration due to low-frequency components is greater than the ratio of vibration due to high-frequency components, the parameter adjustment unit 22 increases the adjustment ratio of the first control parameter (i.e., increases the value of P1). On the other hand, when the ratio of vibration due to high-frequency components is greater than the ratio of vibration due to low-frequency components, the parameter adjustment unit 22 increases the adjustment ratio of the second control parameter (i.e., decreases the value of P1).

[0156] Furthermore, when focusing on the amplitude of vibration, the parameter adjustment unit 22 may determine the adjustment ratios of the first control parameter and the second control parameter based on a comparison of the amplitude of the first waveform data and the amplitude of the second waveform data. Specifically, when the amplitude of the first waveform data is larger than the amplitude of the second waveform data, the parameter adjustment unit 22 increases the adjustment ratio of the first control parameter (i.e., increases the value of P1). On the other hand, when the amplitude of the second waveform data is larger than the amplitude of the first waveform data, the parameter adjustment unit 22 increases the adjustment ratio of the second control parameter (i.e., decreases the value of P1).

[0157] As explained above, the parameter adjustment device 2 adjusts the control parameters based on the cause of the vibration, and therefore the vibration can be suppressed appropriately.

[0158] [Effects] The parameter adjustment device 2 according to this embodiment is a parameter adjustment device that adjusts control parameters in a servo system 1 that includes a vibration detection unit 132 that detects vibrations generated in the drive unit 111 that changes the position of the object 4 and the imaging unit 12 that images the object 4, and a control unit (controller 14 and servo control device 15) that controls the drive unit 111 based on set control parameters, and includes a vibration determination unit 21 that acquires information indicating the vibration detected by the vibration detection unit 132 and identifies the cause of the vibration based on the acquired information, and a parameter adjustment unit 22 that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified by the vibration determination unit 21 and outputs the adjusted control parameters to the control unit.

[0159] With this configuration, the parameter adjustment device 2 adjusts the control parameters based on the cause of the vibration, thereby enabling the vibration to be suppressed appropriately, thereby enabling the parameter adjustment device 2 to adjust the control parameters more effectively.

[0160] Furthermore, in the parameter adjustment device 2 according to this embodiment, the vibration detection unit 132 generates first waveform data indicating the vibration of the imaging unit 12 and second waveform data indicating the vibration of the drive unit 111 based on the information, and the vibration determination unit 21 aligns the phases of the first waveform data and the second waveform data, taking into account the time delay when acquiring the first waveform data and the second waveform data, to identify the cause of the vibration.

[0161] With this configuration, the parameter adjustment device 2 can identify the cause of vibration based on the first waveform data and the second waveform data for the same time period.

[0162] Furthermore, in the parameter adjustment device 2 according to this embodiment, the vibration detection unit 132 generates first waveform data indicating the vibration of the imaging unit 12 and second waveform data indicating the vibration of the drive unit 111 based on the information, and the vibration determination unit 21 determines whether the values ​​contained in the first waveform data and the second waveform data exceed a threshold value, and based on the determination, identifies whether the cause of the vibration is the imaging unit 12, the drive unit 111, or both the imaging unit 12 and the drive unit 111.

[0163] With this configuration, the parameter adjustment device 2 uses a threshold value to identify whether the cause of the vibration is the vibration of the imaging unit 12, the vibration of the drive unit 111, or the vibration of the imaging unit 12 and the vibration of the drive unit 111, thereby clearly isolating the cause of the vibration.

[0164] Furthermore, in the parameter adjustment device 2 according to this embodiment, the control unit includes a controller 14 that performs feedback control to bring the position of the object 4 imaged by the imaging unit 12 closer to a target position, and a servo control device 15 that performs feedback control to bring the moving speed of the object 4 closer to a target speed, and the parameter adjustment unit 22 adjusts the value of at least one of the control parameters, a first control parameter which is a control parameter for the controller 14 and a second control parameter which is a control parameter for the servo control device 15, based on the cause of vibration identified by the vibration determination unit 21.

[0165] With this configuration, the parameter adjustment device 2 adjusts the value of at least one of the first and second control parameters based on the cause of vibration in a servo system that performs two types of feedback control, thereby accurately suppressing vibration in the servo system 1 that performs two types of feedback control.

[0166] Furthermore, in the parameter adjustment device 2 according to this embodiment, when the vibration determination unit 21 determines that the cause of the vibration is the imaging unit 12, the parameter adjustment unit 22 adjusts the value of the first control parameter; when the vibration determination unit 21 determines that the cause of the vibration is the driving unit 111, the parameter adjustment unit 22 adjusts the value of the second control parameter; and when the vibration determination unit 21 determines that the cause of the vibration is both the imaging unit 12 and the driving unit 111, the parameter adjustment unit 22 adjusts the value of the first control parameter and the value of the second control parameter.

[0167] With this configuration, the parameter adjustment device 2 adjusts at least one of the value of the first control parameter and the value of the second control parameter depending on the cause of the vibration, so that the cause of the vibration is identified and the vibration is appropriately suppressed.

[0168] In the parameter adjustment device 2 according to this embodiment, the parameter adjustment unit 22 further outputs at least one of data relating to the cause of vibration and data relating to the adjusted control parameter to the display unit 3 .

[0169] With this configuration, the parameter adjustment device 2 displays the data on the display unit 3, allowing the user to confirm at least one of the cause of the vibration and the result of the adjustment of the control parameter.

[0170] Furthermore, the parameter adjustment method according to this embodiment is a parameter adjustment method executed by a computer that adjusts control parameters in a servo system 1 that includes a vibration detection unit 132 that detects vibrations generated in a drive unit 111 that changes the position of an object 4 and an imaging unit 12 that images the object 4, and a control unit that controls the drive unit 111 based on set control parameters, and includes a vibration determination step that acquires information indicating the vibration detected by the vibration detection unit 132 and identifies the cause of the vibration based on the acquired information, and a parameter adjustment step that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified in the vibration determination step and outputs the adjusted control parameters to the control unit.

[0171] With this configuration, the parameter adjustment method adjusts the control parameters based on the cause of the vibration, and therefore, the control parameters can be adjusted only to those that require adjustment, which allows the parameter adjustment method to adjust the control parameters more effectively.

[0172] The program according to the present embodiment causes a computer to execute a parameter adjustment method.

[0173] With this configuration, the program enables the computer to adjust the control parameters more effectively.

[0174] (Other Embodiments) The parameter adjustment device, parameter adjustment method, and program according to the present disclosure have been described above based on the above-described embodiments, but the present disclosure is not limited to the above-described embodiments. As long as they do not deviate from the spirit of the present disclosure, various modifications conceivable by those skilled in the art to the above-described embodiments, or forms constructed by combining components of different embodiments, may also be included within the scope of one or more aspects.

[0175] In the above-described embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0176] In the above-described embodiments, some or all of the functions of the components may be realized by a processor such as a CPU executing a program. The program according to the present disclosure may be realized as a computer-readable non-transitory recording medium on which the program is recorded, or as a program product including the program.

[0177] Some or all of the components constituting each of the above devices may be configured as an IC card or a standalone module that can be attached to or detached from each device. The IC card or module is a computer system composed of a microprocessor, ROM, RAM, etc. The IC card or module may include a super multi-function LSI. The IC card or module achieves its functions when the microprocessor operates in accordance with a computer program. The IC card or module may be tamper-resistant.

[0178] [Additional Notes] The above description of the embodiments discloses the following techniques.

[0179] (Technology 1) In a servo system including a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, a parameter adjustment device that adjusts the control parameters includes: a vibration determination unit that acquires information indicating the vibration detected by the vibration detection unit and identifies a cause of the vibration based on the acquired information; and a parameter adjustment unit that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified by the vibration determination unit and outputs the control parameters to the control unit.

[0180] (Technology 2) The parameter adjustment device described in Technology 1, wherein the vibration detection unit generates first waveform data indicating vibration of the imaging unit and second waveform data indicating vibration of the drive unit based on the information, and the vibration determination unit aligns the phases of the first waveform data and the second waveform data taking into account a time delay when acquiring the first waveform data and the second waveform data, thereby identifying the cause of the vibration.

[0181] (Technology 3) The parameter adjustment device described in Technology 1 or 2, wherein the vibration detection unit generates first waveform data indicating vibration of the imaging unit and second waveform data indicating vibration of the drive unit based on the information, and the vibration determination unit determines whether a value included in the first waveform data and a value included in the second waveform data exceed a threshold value, and based on the determination, identifies whether the cause of the vibration is the imaging unit, the drive unit, or both the imaging unit and the drive unit.

[0182] (Technology 4) A parameter adjustment device according to any one of Technologies 1 to 3, wherein the control unit includes a controller that performs feedback control to bring the position of the object imaged by the imaging unit closer to a target position, and a servo control device that performs feedback control to bring the moving speed of the object closer to a target speed, and the parameter adjustment unit adjusts the value of at least one of a first control parameter that is a control parameter for the controller and a second control parameter that is a control parameter for the servo control device, based on the cause of the vibration identified by the vibration determination unit.

[0183] (Technology 5) The parameter adjustment device described in Technology 4, wherein the parameter adjustment unit adjusts the value of the first control parameter when the vibration determination unit determines that the cause of the vibration is the imaging unit, adjusts the value of the second control parameter when the vibration determination unit determines that the cause of the vibration is the drive unit, and adjusts the value of the first control parameter and the value of the second control parameter when the vibration determination unit determines that the cause of the vibration is both the imaging unit and the drive unit.

[0184] (Technology 6) The parameter adjustment device according to any one of Techniques 1 to 5, wherein the parameter adjustment unit further outputs at least one of data relating to the cause of the vibration and data relating to the adjusted control parameter to a display unit.

[0185] (Technology 7) In a servo system including a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, a parameter adjustment method executed by a computer that adjusts the control parameters includes a vibration determination step that acquires information indicating the vibration detected by the vibration detection unit and identifies a cause of the vibration based on the acquired information, and a parameter adjustment step that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified in the vibration determination step and outputs the control parameters to the control unit.

[0186] (Technology 8) A program for causing the computer to execute the parameter adjustment method according to Technology 7.

[0187] A parameter adjustment device or the like according to the present disclosure is useful, for example, as a device for adjusting control parameters in a servo system that performs two types of feedback control.

[0188] REFERENCE SIGNS LIST 1 Servo system 11 Stage 111 Drive unit 112 Conversion mechanism 113 Encoder 114 Differentiator 115 Table 116 Base plate 117 Vibration isolation table 118 Installation table 119 Fixture 12 Imaging unit 13 Terminal device 131 Image processing unit 1311 Image acquisition unit 1312 Marker position detection unit 132 Vibration detection unit 14 Controller 141 Coordinate conversion unit 142, 152 Differentiator 143 Calculation unit 144 Speed ​​limit unit 15 Servo control device 151 Speed ​​measurement unit 153 Control voltage generation unit 2 Parameter adjustment device 21 Vibration determination unit 22 Parameter adjustment unit 3 Display unit 31 Trace data display area 32 Vibration cause display area 33 Control parameter display area 4 Object 5 Work table

Claims

1. A parameter adjustment device for adjusting the control parameters in a servo system comprising a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, the parameter adjustment device comprising: a vibration determination unit that acquires information indicating the vibration detected by the vibration detection unit and identifies the cause of the vibration based on the acquired information; and a parameter adjustment unit that adjusts the control parameters to suppress the vibration based on the cause of the vibration identified by the vibration determination unit and outputs the adjusted control parameters to the control unit.

2. The parameter adjustment device of claim 1, wherein the vibration detection unit generates first waveform data indicating vibration of the imaging unit and second waveform data indicating vibration of the drive unit based on the information, and the vibration determination unit aligns the phases of the first waveform data and the second waveform data, taking into account the time delay when acquiring the first waveform data and the second waveform data, to identify the cause of the vibration.

3. The parameter adjustment device of claim 1, wherein the vibration detection unit generates first waveform data indicating vibration of the imaging unit and second waveform data indicating vibration of the drive unit based on the information, and the vibration determination unit determines whether a value included in the first waveform data and a value included in the second waveform data exceed a threshold value, and based on the determination, identifies whether the cause of the vibration is the imaging unit, the drive unit, or both the imaging unit and the drive unit.

4. The parameter adjustment device according to any one of claims 1 to 3, wherein the control unit includes a controller that performs feedback control to bring the position of the object imaged by the imaging unit closer to a target position, and a servo control device that performs feedback control to bring the moving speed of the object closer to a target speed, and the parameter adjustment unit adjusts the value of at least one of a first control parameter that is a control parameter for the controller and a second control parameter that is a control parameter for the servo control device, based on the cause of the vibration identified by the vibration determination unit.

5. The parameter adjustment device according to claim 4, wherein the parameter adjustment unit adjusts the value of the first control parameter when the vibration determination unit determines that the vibration is caused by the imaging unit, adjusts the value of the second control parameter when the vibration determination unit determines that the vibration is caused by the drive unit, and adjusts the value of the first control parameter and the value of the second control parameter when the vibration determination unit determines that the vibration is caused by both the imaging unit and the drive unit.

6. The parameter adjustment device according to claim 1, wherein the parameter adjustment unit further outputs at least one of data relating to the cause of the vibration and data relating to the adjusted control parameter to a display unit.

7. A parameter adjustment method executed by a computer that adjusts the control parameters in a servo system comprising a vibration detection unit that detects vibrations generated in a drive unit that changes the position of an object and an imaging unit that images the object, and a control unit that controls the drive unit based on set control parameters, the parameter adjustment method comprising: a vibration determination step of acquiring information indicating the vibration detected by the vibration detection unit and identifying the cause of the vibration based on the acquired information; and a parameter adjustment step of adjusting the control parameters to suppress the vibration based on the cause of the vibration identified in the vibration determination step, and outputting the adjusted control parameters to the control unit.

8. A program for causing a computer to execute the parameter adjustment method according to claim 7.

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