Drive system

Abstract

Provided is a drive system capable of simply and smoothly suppressing vibration generated in a detection object. A drive system (1) is provided with: an image processing unit (321) that processes images from cameras (21, 22) that capture at least a drive range of a driven unit and extracts a detection target; a vibration calculation unit (322) that calculates a vibration component of the detection object on the basis of the difference between the extracted position of the detection object and the target position of the detection object; and a control signal correction unit (323) that suppresses vibration of the detection target by correcting a control signal for driving the driven unit using the vibration component.

Description

Technical Field

[0001] The present disclosure relates to a drive system for driving a driven part. Background Art

[0002] In the past, drive systems that drive driven parts have been used in various fields. For example, as an example of a drive system, a robot hand that holds and transfers objects can be cited. In this case, the arm, hand, or object held in the hand of the robot hand becomes the driven part of the drive system. In addition, as another example of a drive system, a processing device that moves the light-emitting part of a laser in one direction to cut a substrate, etc. can be cited. In this case, the light-emitting part becomes the driven part of the drive system. In addition, an XYZθ worktable that adjusts the position of an object placed on the worktable can also be cited as an example of a drive system.

[0003] In these drive systems, control is performed so as to drive the driven part to move to a predetermined target position. In this case, vibration generated in the driven part may become an obstacle to control.

[0004] For example, a robot hand can be controlled to move the hand at high speed to transfer objects more quickly. However, this control applies steep and large accelerations to the hand at the beginning and end of the movement. This acceleration can cause vibrations in the hand. Furthermore, vibrations from other drive systems can propagate to the robot hand, sometimes causing vibrations in the hand or arm. Such vibrations can also occur in drive systems other than the robot hand.

[0005] These vibrations may hinder the target control of the driven parts. Therefore, the drive system stops driving the driven parts while the vibrations are generated, or performs control to suppress the vibrations in parallel with the drive control of the driven parts.

[0006] For example, Patent Document 1 below describes a robot control device that uses an acceleration sensor installed in a robot arm to suppress vibration. This device obtains the difference between the motor speed of each axis, obtained from the acceleration sensor's signal, and the motor speed obtained from simulation as a vibration component. This vibration component is fed back to the motor drive control to suppress vibration generated in the robot arm.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-161562 Summary of the Invention

[0010] The method disclosed in Patent Document 1 requires installing an acceleration sensor separately for each vibrating object. However, if the object is extremely small, placing the acceleration sensor on the object is difficult. Furthermore, if the object is an object being transported by a robotic arm, an acceleration sensor must be installed for each object. Furthermore, the acceleration sensor must be reinstalled each time the object is changed. This is an extremely complex task.

[0011] In view of the above-mentioned problems, an object of the present disclosure is to provide a drive system that can simply and smoothly suppress vibrations generated in a probe target.

[0012] The driving system involved in the main embodiment of the present disclosure includes: an image processing unit, which processes an image from a camera that captures at least the driving range of the driven part to extract a detection object; a vibration calculation unit, which calculates the vibration component of the detection object based on the difference between the extracted position of the detection object and the target position of the detection object; and a control signal correction unit, which corrects the control signal used to drive the driven part by using the vibration component, thereby suppressing the vibration of the detection object.

[0013] This drive system can suppress vibrations of the driven object by correcting the control signal based on the camera image, even without attaching an accelerometer or other sensor to the driven object. Furthermore, since the camera image is used, the driven object can be positioned anywhere within the driven object without restriction. This allows for simple and smooth suppression of vibrations generated by the driven object.

[0014] In the above description, the "detection target" refers to a portion of the driven part driven by the drive system that is designated as the target for vibration detection and suppression. For example, if the drive system is a robot arm, a portion of the robot arm's hand, a portion of the arm, or a portion of an object held by the hand can be designated as the "detection target."

[0015] If the target area for vibration detection and suppression has a characteristic shape and can be appropriately extracted through image processing, the "detection target" may be the area itself. On the other hand, if the target area for vibration detection and suppression does not have a characteristic shape and is difficult to accurately extract through image processing, for example, a separate label may be added to the area as the "detection target."

[0016] As described above, according to the drive system according to the present disclosure, it is possible to provide a drive system that can simply and smoothly suppress vibrations generated in a detection target. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side view showing the structure of the drive system according to the embodiment.

[0018] Figure 2 This is a block diagram showing the configuration of a circuit unit of a drive system according to the embodiment.

[0019] Figure 3 This is a block diagram showing the configuration of a controller according to the embodiment.

[0020] Figure 4A It is a diagram showing a calculation process of a vibration component in a vibration calculation unit according to the embodiment.

[0021] Figure 4B It is a diagram showing a calculation process of a vibration component in a vibration calculation unit according to the embodiment.

[0022] Figure 5 It is a timing chart showing a control signal correction method according to the embodiment.

[0023] Figure 6 This is a flowchart showing a process for suppressing vibration generated in a detection target according to an embodiment.

[0024] Figure 7 This is a flowchart showing a correction process of a control signal according to the embodiment.

[0025] Figure 8 This is a flowchart showing a process for suppressing vibration generated in the detection target according to Modification Example 1.

[0026] Figure 9 This is a timing chart showing an example of the vibration suppression operation according to Modification Example 1.

[0027] Figure 10 It is a diagram showing the configuration of a drive system according to Modification Example 2.

[0028] Figure 11 This is a block diagram showing the configuration of a circuit unit of a drive system according to Modification Example 2. DETAILED DESCRIPTION

[0029] The effects and significance of the invention disclosed herein will become more apparent through the following description of the embodiments. However, the embodiments described below are merely examples of implementing the present invention, and the present disclosure is not limited in any way by the contents described in the following embodiments.

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0031] In the following embodiments, the present disclosure is applied to a drive system for a robotic arm. In addition to the arm and hand, the object held in the hand also corresponds to the driven part. In the following embodiments, a portion of the object is set as the detection target. However, the application of the present disclosure is not limited to this drive system. The present disclosure can be applied to various drive systems for driving driven parts.

[0032] Figure 1 1 is a side view showing the structure of the drive system 1. Figure 1 The positive direction of the Z axis is the vertical upward direction, which is the height direction of the robot arm 10.

[0033] The drive system 1 includes a robot arm 10, cameras 21 and 22, a control unit 30, and an operation terminal 40. The robot arm 10 is a driven unit that grasps an object 50 (included in the driven unit) at the start position of transfer and transfers it to the end position of transfer. The robot arm 10 includes an arm 11 and a hand 12, each of which is included in the driven unit. The camera 21 is a two-dimensional camera equipped with an imaging lens and an imaging element such as a CCD (Charge Coupled Device). The imaging range of cameras 21 and 22 includes at least the entire drive range of the robot arm 10 (arm 11 and hand 12). One camera 21 is positioned downward so that the optical axis of the imaging lens is approximately parallel to the vertical direction (Z-axis direction). The other camera 22 is positioned horizontally so that the optical axis of the imaging lens is approximately parallel to the horizontal direction (X-axis direction).

[0034] The control unit 30 controls the robot arm 10 to transfer the object 50 between the aforementioned transfer start and end positions. The transfer start and end positions are set by the user via the operation terminal 40. The user also sets the transfer path (transfer trajectory) for the object 50 between the transfer start and end positions via the operation terminal 40. Alternatively, the operation terminal 40 may calculate and set an optimal transfer path (transfer trajectory) based on the user-set transfer start and end positions. The set transfer start and end positions, as well as the transfer trajectory, are provided from the operation terminal 40 to the control unit 30. Based on this information, the control unit 30 controls the robot arm 10.

[0035] The robot arm 10 is a so-called multi-joint robot and includes an arm 11 and a hand 12. The arm 11 is rotated about a rotation axis parallel to the Z axis by a first drive unit 11a provided on an installation surface (eg, the floor). Figure 1 The arm 11 is parallel to the XZ plane. The arm 11 can be rotated by the second drive unit 11b and the third drive unit 11c. Figure 1In this state, the rotation axes of the second driving part 11b and the third driving part 11c are parallel to the Y axis.

[0036] A hand 12 is provided at the front end of the arm 11. Here, the hand 12 is shown as a structure that uses multiple claws to grasp the article 50. The hand 12 may also be a structure that uses negative pressure to suck the article 50 instead of the claws to hold the article 50.

[0037] Two cameras 21 and 22 are used to detect vibrations in the detection target TP. Here, the detection target TP is set to a portion of the object 50. One camera 21 is used to detect vibrations in the detection target TP in the X-axis direction. The other camera 22 is used to detect vibrations in the detection target TP in the Y-axis direction and the Z-axis direction, respectively.

[0038] The control unit 30 processes the images from the cameras 21 and 22, extracts the probe object TP, and calculates the vibration generated in the extracted probe object TP. The control unit 30 then corrects the control signal used to drive the robot arm 10 and drives the robot arm 10 using the corrected control signal to suppress the calculated vibration.

[0039] The detection target TP is set by the user via the operation terminal 40. The detection target TP is set, for example, through the following steps.

[0040] The robot arm 10, holding the object 50, remains stationary in a predetermined posture. In this state, the images captured by the cameras 21 and 22 are transmitted to the operation terminal 40 via the control unit 30. The operation terminal 40 displays these images. The user operates to define the range of the detection target TP using these displayed images. The operation terminal 40 transmits each image containing the range of the detection target TP determined by the user to the control unit 30.

[0041] The control unit 30 stores these images and extracts an image of the vicinity of the detection target TP from these images, and stores the extracted image as the set image of the detection target TP. At this time, the control unit 30 stores the information defining the static posture, that is, the rotation amount ( Figure 2 The detection value of the encoder 112 is associated with each set image. This information can also be acquired and stored for multiple static postures. In this way, the setting of the detection target TP for the control unit 30 is completed.

[0042] During actual operation, the control unit 30 compares the images captured by each of the cameras 21 and 22 with the preset images for each camera 21 and 22, which were stored in the aforementioned process. The control unit 30 extracts the range in each image that matches the corresponding preset image as the detection target TP. The control unit 30 then calculates the vibration of the extracted detection target TP and corrects the control signal of the robot arm 10 to suppress this vibration.

[0043] Figure 2 It is a block diagram showing the configuration of the circuit portion of the drive system 1 .

[0044] The arm portion 11 of the robot arm 10 includes a motor 111 and an encoder 112. Figure 2 Only one set of motor 111 and encoder 112 is described in the text, but in fact, Figure 1 The first drive unit 11a, second drive unit 11b, and third drive unit 11c each have multiple sets of motors 111 and encoders 112. Motors 111 drive the corresponding drive unit about a rotation axis, while encoders 112 output detection signals corresponding to the rotation angle. Motors 111 are, for example, stepping motors or AC servo motors, and encoders 112 are rotary encoders.

[0045] The hand 12 of the robot arm 10 includes a motor 121 and a sensor 122. The motor 121 is a driving source for driving the claws of the hand 12. The motor 121 is, for example, a stepping motor. The sensor 122 detects the opening and closing of the claws of the hand 12.

[0046] The control unit 30 includes a controller 31 , a controller 32 , an arm driving circuit 33 , and a finger driving circuit 34 as a circuit unit.

[0047] The controller 31 is composed of a microcomputer and the like, and controls each part of the robot arm 10. The controller 31 controls the arm 11 and the hand 12 to transfer the article 50 from the transfer start position to the transfer end position.

[0048] As described above, the controller 31 sets the hand 12's transfer start and end positions, as well as the transfer trajectory for moving the hand 12 from the transfer start position to the transfer end position, via the operation terminal 40. During the hand 12 transfer process, the controller 31 detects the hand 12's current position at each fixed control timing based on the detection signals output from the encoders 112 of each drive unit. The controller 31 then generates a control signal to adjust the hand 12's position to follow the transfer trajectory and outputs the generated control signal to the controller 32 at the next control timing.

[0049] The controller 32 is composed of a microcomputer, FPGA (Field Programmable Gate Array), etc., and corrects the control signal input from the controller 31 based on the images from the cameras 21 and 22. In this correction, the controller 32 detects the vibration of the detection object TP from the images of the cameras 21 and 22 and corrects the control signal to suppress the detected vibration. The structure and operation of the controller 32 will be described later. Figures 3 to 7 Provide explanation.

[0050] The arm drive circuit 33 drives the motor 111 based on a control signal input from the controller 32, thereby driving the arm 11. The finger drive circuit 34 drives the motor 121 based on a control signal input from the controller 31, thereby opening and closing the claws of the hand 12. At the start of transfer, the controller 31 outputs a control signal for gripping the object 50 to the finger drive circuit 34 while referencing the detection signal from the sensor 122. Furthermore, at the end of transfer, the controller 31 outputs a control signal for releasing the object 50 to the finger drive circuit 34 while referencing the detection signal from the sensor 122.

[0051] Figure 3 3 is a block diagram showing the configuration of the controller 32 .

[0052] The controller 32 includes an image processing unit 321 , a vibration calculation unit 322 , and a control signal correction unit 323 .

[0053] The image processing unit 321 acquires images from the cameras 21 and 22 at each control timing, analyzes each acquired image, and extracts the detection target TP from each image. The image processing unit 321 outputs the position of the extracted detection target TP on each image to the vibration calculation unit 322.

[0054] Before acquiring the position of the probe target TP from the image processing unit 321 , the vibration calculation unit 322 acquires the target position of the probe target TP on each image at each control timing from the controller 31 in advance.

[0055] Specifically, the controller 31 calculates the transfer trajectory of the probe target TP based on the transfer trajectory of the hand 12 and the positional relationship between the hand 12 and the probe target TP. The controller 31 then determines the position of the probe target TP at each control timing on the transfer trajectory of the probe target TP and converts the determined position into a position on the images of the cameras 21 and 22. The controller 31 outputs the converted position as the target position of the probe target TP at each control timing on each image to the vibration calculation unit 322.

[0056] The vibration calculation unit 322 calculates the difference between the position of the probe target TP input from the image processing unit 321 and the target position of the probe target TP at the control timing as the vibration component of the probe target TP.

[0057] Figure 4A as well as Figure 4B 3 is a diagram showing the calculation process of the vibration component in the vibration calculation unit 322. Figure 4A 、 Figure 4B Calculation processing of the vibration component in the X-axis direction using the image from the camera 21 is shown in FIG.

[0058] about Figure 4A The dotted line in FIG. 1 calculates the displacement component in the X-axis direction (displacement from the initial position) based on the target's transfer trajectory (the target's transfer trajectory on the camera 21 image) of the detection target TP, and displays the temporal variation of the calculated displacement component as a waveform. The target's transfer trajectory is equivalent to the trajectory obtained by extracting the displacement component in the X-axis direction from the transfer trajectory formed by connecting the target positions of the detection target TP on the camera 21 image at each control timing, which is supplied from the controller 31 to the vibration calculation unit 322.

[0059] about Figure 4A The solid line is obtained by calculating the displacement component in the X-axis direction (displacement from the initial position) of the position of the detection object TP extracted from the image of the camera 21 by the image processing unit 321 at each control timing, and the calculated displacement components are connected to represent the time change in the X-axis direction of the position of the detection object TP as a waveform. Figure 4A The solid line shows a waveform when the probe object TP generates vibrations including a vibration component in the X-axis direction.

[0060] like Figure 4A As shown, if a vibration component in the X-axis direction is generated in the detection target TP, the waveform (solid line) of the displacement of the detection target TP in the X-axis direction, extracted from the image of the camera 21, will vibrate relative to the waveform (dashed line) of the target transfer trajectory of the detection target TP due to this vibration component. Therefore, by subtracting the waveform of the dashed line from the waveform of the solid line, the vibration component of the detection target TP in the X-axis direction can be calculated.

[0061] Figure 4B It is from Figure 4A A waveform obtained by subtracting the displacement component of the dotted line waveform from the displacement component of the solid line waveform.

[0062] like Figure 4B As shown, by Figure 4A By subtracting the waveform of the dotted line from the waveform of the solid line, the waveform of the vibration component in the X-axis direction of the probe object TP can be obtained. Figure 3The vibration calculation unit 322 calculates the vibration component in the X-axis direction at each control timing as follows. That is, the position in the X-axis direction is calculated for the position of the detection object TP in the image of the camera 21 input from the image processing unit 321. In addition, the position in the X-axis direction is calculated for the target position of the detection object TP on the image input from the controller 31. Then, by subtracting the target position in the X-axis direction of the detection object TP from the calculated position in the X-axis direction of the detection object TP, the vibration component in the X-axis direction of each control timing is calculated. In this way, the vibration component in the X-axis direction can be calculated. Figure 4B Same vibration component.

[0063] In addition, here, the method of calculating the vibration component of the detection object TP in the X-axis direction is described, but by performing the same processing on the image from another camera 22, the vibration components in the Y-axis direction and the Z-axis direction can be calculated in the same manner.

[0064] Specifically, the vibration calculation unit 322 calculates the Y-axis vibration component at each control timing as follows. Specifically, the Y-axis position of the detection target TP in the image from the camera 22, input from the image processing unit 321, is calculated. Furthermore, the Y-axis position of the detection target TP in the image input from the controller 31 is calculated. The Y-axis vibration component at each control timing is then calculated by subtracting the target Y-axis position of the detection target TP from the calculated Y-axis position of the detection target TP. This allows the Y-axis vibration component of the detection target TP to be calculated.

[0065] Furthermore, the vibration calculation unit 322 calculates the vibration component in the Z-axis direction at each control timing as follows. Specifically, the Z-axis position of the detection target TP in the image from the camera 22, input from the image processing unit 321, is calculated. Furthermore, the Z-axis position of the detection target TP in the image input from the controller 31 is calculated. The Z-axis position of the detection target TP is then subtracted from the calculated Z-axis position of the detection target TP to calculate the vibration component in the Z-axis direction at each control timing. This allows the Z-axis vibration component of the detection target TP to be calculated.

[0066] return Figure 3The vibration calculation unit 322 outputs the calculated vibration components of the probe target TP in the X-axis direction, the Y-axis direction, and the Z-axis direction to the control signal correction unit 323. Based on the vibration components in each direction input from the vibration calculation unit 322, the control signal correction unit 323 corrects the control signal input from the controller 31 to suppress each vibration component, and outputs the corrected control signal to the arm drive circuit 33. The arm drive circuit 33 drives the arm 11 using the corrected control signal. In this way, by driving the arm 11 using the corrected control signal, the vibration of the probe target TP is suppressed.

[0067] Figure 5 This is a timing diagram showing a method for correcting a control signal.

[0068] The following correction method is suitable for the case where the vibration period of the probe object TP is several times or more than 10 times the period of the control timing. For example, when the vibration period of the probe object TP is 100ms, the period of the control timing is preferably less than 10ms.

[0069] exist Figure 5 In the correction method, the control timing near the peak of the change in the vibration component is determined. Then, a correction signal corresponding to the magnitude of the vibration component calculated by the vibration calculation unit 322 at the determined control timing is superimposed on the control signal in an opposite phase. This correction is performed when the magnitude of the vibration component exceeds a given threshold range Th1 to Th2. When the magnitude of the vibration component does not exceed the given threshold range Th1 to Th2, the above-mentioned correction is not performed, and the control signal from the controller 31 is directly supplied to the arm drive circuit 33. The threshold range Th1 to Th2 is set to have the same width in positive and negative directions with zero as the reference.

[0070] Figure 5 A method for correcting the vibration component in the X-axis direction is shown. Figure 5 Waveforms W1, W2, and W3 in FIG. 1 represent the temporal variations in the vibration component of the probe object TP in the X-axis direction, extracted from the image of camera 21. Waveform W2 represents the vibration component that was not completely suppressed by the correction based on the preceding waveform W1, and waveform W3 represents the vibration component that was not completely suppressed by the correction based on the preceding waveform W2. The solid lines of waveforms W1 and W2 represent the waveforms of vibration that occurred before correction, while the dashed lines of waveforms W1 and W2 represent the waveforms of vibration that continued without correction. Waveform W3 is represented entirely by a solid line because no correction was performed.

[0071] exist Figure 5 In the control timing D1, it is determined that a peak has occurred in the waveform W1. For example, the peak is determined by switching the increasing and decreasing directions of the displacement component in the X-axis direction.

[0072] That is, within the range of positive displacement components, the control timing at which the displacement component of the current control timing changes from being larger than the displacement component of the immediately preceding control timing to being smaller than the displacement component of the immediately preceding control timing is determined as the control timing at which the peak occurs. Furthermore, within the range of negative displacement components, the control timing at which the displacement component of the current control timing changes from being smaller than the displacement component of the immediately preceding control timing to being larger than the displacement component of the immediately preceding control timing is determined as the control timing at which the peak occurs.

[0073] In this way, once control timing D1, at which a peak occurs, is determined, a correction signal for displacing the arm 11 in the X-axis direction is superimposed on the control signal (the X-axis signal component of the control signal) from the controller 31 at the next control timing C1, which is the correction timing, at a drive amount of the opposite phase to that required to cancel the X-axis vibration component A at control timing D1. As a result, X-axis vibration is suppressed at the next control timing C1.

[0074] However, at the next control timing C1, the actual X-axis direction vibration component B is smaller than the vibration component A. Therefore, at the next control timing C1, the difference BA between the vibration component A and the vibration component B is excessively corrected. As a result, a vibration corresponding to the new waveform W2 is generated in the probe target TP from this control timing C1 onward.

[0075] In this case, the vibration is also suppressed by the same process as above. Here, a peak is determined at control timing D2, and a correction signal is superimposed on the control signal at the next control timing C2. This correction signal is used to displace the arm 11 in the X-axis direction by a drive amount that is opposite in phase to that used to cancel the X-axis vibration component at control timing D2.

[0076] This correction allows the vibration of the probed object TP to converge substantially as shown by waveform W3, and the X-axis vibration of the probed object TP falls within the threshold range Th1-Th2. Therefore, until the probed object TP generates new vibrations exceeding the threshold range Th1-Th2, the X-axis vibration suppression process, i.e., the control signal correction process, is not performed. This completes the control signal correction process for X-axis vibration.

[0077] Furthermore, regarding vibrations in the Y-axis direction and the Z-axis direction, the control signal is corrected by the same processing as described above, thereby suppressing vibrations in these directions.

[0078] That is, regarding the vibration in the Y-axis direction, Figure 5The vertical axis is changed to the vibration component (displacement) in the Y-axis direction, and the control timing at which the peak of this vibration component occurs is determined. Then, at the next control timing, a correction signal for displacing arm 11 in the Y-axis direction with a drive amount that is opposite in phase to that required to cancel the vibration component at that control timing is superimposed on the control signal (the Y-axis signal component) from controller 31. This process is repeated until the vibration in the Y-axis direction falls within the threshold range Th1-Th2.

[0079] In addition, regarding the vibration in the Z-axis direction, Figure 5 The vertical axis is changed to the vibration component (displacement) in the Z-axis direction, and the control timing at which the peak of this vibration component occurs is determined. Then, at the next control timing, a correction signal for displacing arm 11 in the Z-axis direction with a drive amount that is opposite in phase to that required to cancel the vibration component at that control timing is superimposed on the control signal (the Z-axis signal component) from controller 31. This process is repeated until the vibration in the Z-axis direction falls within the threshold range Th1-Th2.

[0080] In this way, vibrations in various directions in the probe target TP are suppressed.

[0081] Figure 6 3 is a flowchart showing a process for suppressing vibration generated in the probe object TP.

[0082] Figure 6 In the processing, steps S101 and S102 are performed by the image processing unit 321 , step S103 is performed by the vibration calculation unit 322 , and steps S104 and S105 are performed by the control signal correction unit 323 .

[0083] When the transfer operation starts, the image processing unit 321 acquires images from the cameras 21 and 22 at the current control timing ( S101 ), extracts the position of the probe target TP from each acquired image ( S102 ), and outputs the acquired position to the vibration calculation unit 322 .

[0084] The vibration calculation unit 322 calculates the position of the probe object TP on each input image by Figure 4A and Figure 4B The processing shown calculates the vibration components of the probe target TP in the X-axis direction, the Y-axis direction, and the Z-axis direction ( S103 ). The vibration calculation unit 322 outputs the calculated vibration components in each direction to the control signal correction unit 323 .

[0085] The control signal correction unit 323 determines whether the input vibration components in each direction exceed the threshold range Th1-Th2 (S104). For directions where the vibration components exceed the threshold range Th1-Th2 (S104: Yes), the control signal correction unit 323 performs a correction process to suppress the vibration and corrects the control signal from the controller 31 (S105). For directions where the vibration components do not exceed the threshold range Th1-Th2 (S104: No), the control signal correction unit 323 outputs the control signal from the controller 31 without performing any correction process.

[0086] Figure 7 It is shown in Figure 6 Flowchart of the correction processing performed in step S105.

[0087] In addition, Figure 7 In the process, at each control timing until step S114 becomes “Yes”, the control signal from the controller 31 is not corrected but is directly output from the control signal correction unit 323 to the arm drive circuit 33 .

[0088] At the next control timing, the image processing unit 321 acquires an image from the camera used for calibration, one of the two cameras 21 and 22 (S111). The image processing unit 321 extracts the position of the detection target TP from the acquired image and outputs the extracted position of the detection target TP to the vibration calculation unit 322 (S112). The vibration calculation unit 322 calculates the vibration component in the calibration direction based on the input position of the detection target TP and outputs the calculated vibration component to the control signal correction unit 323 (S113).

[0089] The control signal correction unit 323 is Figure 5 The process shown in FIG. 1 determines whether the current control timing is the control timing at which the vibration reaches its peak value (S114). If the determination in step S114 is “No”, the process after step S111 is repeated. If the determination in step S114 is “Yes”, the process is repeated as follows. Figure 5 As shown, the control signal correction unit 323 superimposes the correction signal of the driving amount of the opposite phase for eliminating the vibration component in the direction of the current control timing on the control signal from the controller 31 (S115). The control signal correction unit 323 performs this process for each direction to be corrected. Figure 7 The correction process is completed.

[0090] return Figure 6 If the processing of step S105 is completed, the various parts of the controller 32 repeatedly execute the processing of steps S101 to S105 until the transfer operation is completed (S106: No). Afterwards, if the transfer operation is completed (S106: Yes), the various parts of the controller 32 end Figure 6 processing.

[0091] <Effects of Implementation>

[0092] According to the above-described embodiment, the following effects are achieved.

[0093] like Figure 3 As shown, the drive system 1 includes an image processing unit 321, a vibration calculation unit 322, and a control signal correction unit 323. The image processing unit 321 processes images from the cameras 21 and 22, which capture at least the driving range of the driven components (arm 11, hand 12, and object 50), to extract the detection target TP. The vibration calculation unit 322 calculates the vibration component of the detection target TP based on the difference between the extracted position of the detection target TP and the target position of the detection target TP. The control signal correction unit 323 uses the vibration component to correct the control signal used to drive the driven components, thereby suppressing the vibration of the detection target TP.

[0094] This allows the control signal to be corrected based on the images from cameras 21 and 22, thereby suppressing vibrations of the detected object TP, even without attaching an acceleration sensor or the like to the detected object TP of the driven part. Furthermore, since the images from cameras 21 and 22 are used, the detected object TP can be set to any position on the driven part without restriction. This allows for simple and smooth suppression of vibrations generated by the detected object TP.

[0095] like Figure 5 as well as Figure 6 As shown, when the vibration component exceeds the predetermined threshold range Th1-Th2, the control signal correction unit 323 corrects the control signal from the controller 31. If the vibration component does not exceed the threshold range Th1-Th2, the control signal correction unit 323 does not perform this correction and directly outputs the control signal from the controller 31. This correction utilizes noise rather than vibration components, thereby suppressing unintended motion in the probe target TP. Consequently, vibrations in the probe target TP can be stably suppressed.

[0096] like Figure 5 As shown, the vibration calculation unit 322 calculates the vibration component at the control timing of each given cycle, and the control signal correction unit 323 determines the control timing (D1, D2) near the peak of the change in the vibration component, and superimposes a correction signal corresponding to the magnitude of the vibration component A calculated at the determined control timing (D1, D2) on the control signal with an opposite phase to correct the control signal.

[0097] In this way, by superimposing a correction signal corresponding to the magnitude of the vibration component A near the peak with an opposite phase, the vibration energy of the driven part can be effectively canceled, allowing the vibration generated in the detection target TP to be quickly and effectively attenuated. Furthermore, because the control timings (D1, D2) are near the peak, the polarity of the vibration component at the next control timing (C1, C2) is generally the same as that at the control timings (D1, D2). Therefore, even if a correction signal with the opposite polarity of the vibration component obtained at the control timings (D1, D2) is superimposed on the control signal at the next control timings (C1, C2), the correction signal will not further increase the vibration. As a result, the vibration of the detection target TP can be stably suppressed.

[0098] like Figure 1 As shown, the driving system 1 includes an operation terminal 40 that receives input from a user. Figure 3 The image processing unit 321 sets the location of the driven part (arm 11, hand 12, object 50) input via the operation terminal 40 as the detection target TP. This allows the user to arbitrarily set the location (detection target TP) for vibration suppression based on the transport operation, the contents of the object, and other factors. Consequently, the drive system 1 can perform vibration suppression control tailored to the transport operation, the contents of the object, and other factors.

[0099] <Change Example 1>

[0100] The embodiments of the present disclosure are not limited to those described above, and various modifications are possible.

[0101] For example, in the above embodiment, as a process for suppressing vibration, Figure 6 as well as Figure 7 However, the processing for suppressing vibration is not limited to this processing.

[0102] Figure 8 1 is a flowchart showing a process for suppressing vibration generated in the probe target TP according to Modification Example 1.

[0103] Figure 8 In the processing, steps S101 and S102 are performed by the image processing unit 321 , step S103 is performed by the vibration calculation unit 322 , and steps S104 and S121 are performed by the control signal correction unit 323 .

[0104] Figure 8 The flowchart will Figure 6 Step S105 of the flowchart is changed to step S121. Figure 8 The other steps of the flowchart are processed with Figure 6 The processing of corresponding steps in the flowchart is the same.

[0105] exist Figure 8In this process, the peak value of the vibration component is not determined. If the vibration component exceeds the threshold range Th1-Th2 (S104: Yes), a correction signal for driving the arm 11 with a drive amount that cancels the vibration component at that control timing is superimposed on the control signal from the controller 31 at the next control timing (S121). In other words, the control signal correction unit 323 corrects the control signal from the controller 31 at each control timing when the vibration component exceeds the threshold range Th1-Th2.

[0106] Figure 9 Is based on Figure 8 A timing diagram of an example of the vibration suppression operation of the processing.

[0107] and Figure 5 The same is true in Figure 9 The figure shows the temporal variation of the vibration component in the X-axis direction calculated from the image of the camera 21. The seven waveforms W11 to W17 are shown here. Waveform Wn is the waveform of the vibration that cannot be completely suppressed by the correction of waveform W(n-1). In addition, n = 11 to 17. Figure 5 Similarly, in waveforms W11 to W17, the solid line portion represents the waveform of the vibration generated before correction, and the dotted line portion represents the waveform of the vibration that continues without correction. As for waveform W17, since no correction is performed, the entire waveform is represented by a solid line.

[0108] exist Figure 9 In the figure, the white circle indicates the control timing at which the vibration component is determined to have exceeded the threshold, and the black circle indicates the next control timing. However, in reality, the vibration component also exceeds the threshold at the control timing in the black circle. However, for convenience, the control timing in the black circle is described here as the control timing used for correction. In practice, the same process is performed as follows, with the control timing in the black circle being the control timing that exceeds the threshold and the control timing in the white circle being the control timing used for correction.

[0109] Regarding the vibration of waveform W11, a correction signal of a magnitude and opposite phase to the vibration component at the control timing of the white circle (indicated by the double-headed arrow) is superimposed on the control signal from controller 31 at the control timing of the black circle. This suppresses the vibration component in the X-axis direction, as shown in waveform W12. However, the correction signal in this case is slightly larger than the threshold range Th1-Th2, so it cannot significantly attenuate the vibration energy of the driven part. As a result, the amplitude of waveform W12 remains slightly smaller than that of waveform W11.

[0110] Similarly, each time a vibration component is determined to have exceeded the threshold range, a correction signal with an opposite phase corresponding to the magnitude of the vibration component at that time is superimposed on the control signal from controller 31 at the next black circle control timing. This gradually attenuates the vibration in the X-axis direction, and the vibration waveform shifts as shown by waveforms W12 to W16. Correcting waveform W16 in this way brings the vibration component in the X-axis direction within the threshold range Th1 to Th2, as shown by waveform W17. This completes the control to suppress the vibration of probe target TP in the X-axis direction.

[0111] The vibration of the probe object TP in the Y-axis and Z-axis directions is also gradually attenuated by the same control operation and converges into the threshold value range Th1 to Th2.

[0112] According to the control of Modification Example 1, although it is not possible to Figure 5 The control shown in the figure effectively suppresses the vibration of the detection object TP at once, but each time the vibration component exceeds the threshold, the vibration can be gradually brought within the threshold range Th1-Th2. Therefore, the vibration of the detection object TP can be quickly and smoothly suppressed without generating large vibrations in the drive system.

[0113] <Change Example 2>

[0114] In the above embodiment, the drive system 1 is configured to include the robot arm 10 , but the drive system 1 is not limited to this configuration.

[0115] Figure 10 : is a diagram showing the structure of the drive system 1 according to Modification Example 2. Figure 10 For convenience, mutually orthogonal X, Y, and Z axes are indicated. The positive direction of the Z axis is the height direction of the processing device 60.

[0116] In the second modification, the drive system 1 includes a processing device 60 that cuts a substrate using laser light.

[0117] The processing device 60 includes a laser unit 61, a drive mechanism 62, a motor 63, an encoder 64, and a setting portion 71. A substrate 72 to be processed is set on the upper surface of the setting portion 71. The processing device 60 moves the laser unit 61 in the X-axis direction to process the substrate 72.

[0118] The drive mechanism 62 includes a ball screw 62a, a pair of fixed members 62b, a movable member 62c, and a guide rail 62d. The ball screw 62a is supported by the pair of fixed members 62b parallel to the X-axis. A bearing provided on the movable member 62c engages with the ball screw 62a. The movable member 62c is slidably supported by the guide rail 62d. The guide rail 62d is supported by the pair of fixed members 62b parallel to the X-axis.

[0119] A motor 63 is provided on one of the pair of fixing members 62b. The rotation shaft of the motor 63 is connected to one end of the ball screw 62a. The motor 63 is provided with an encoder 64. The encoder 64 detects the rotation position of the motor 63.

[0120] The laser unit 61 is mounted on the lower surface of the movable member 62c. The laser unit 61 and the movable member 62c are driven components. The laser unit 61 emits laser light of a predetermined wavelength downward (in the negative Z-axis direction). When the ball screw 62a is rotated by the motor 63, the movable member 62c and the laser unit 61 are moved in the X-axis direction. At this time, the laser light emitted by the laser unit 61 is controlled, and the substrate 72 on the mounting portion 71 is processed using the laser light emitted by the laser unit 61.

[0121] The drive system 1 further includes a camera 20, a control unit 80, and an operation terminal 90. The imaging range of the camera 20 encompasses at least the entire driving range of the driven components (moving member 62c and laser unit 61) of the processing device 60. The camera 20 is positioned forward so that the optical axis of the camera lens is approximately parallel to the Y-axis. The control unit 80 is used to control the processing device 60, and the operation terminal 90 is used to perform configuration operations on the control unit 80.

[0122] In the second modification, a mark M1 is provided on the front surface of the laser unit 61 , and the mark M1 serves as a detection target TP.

[0123] Figure 11 1 is a block diagram showing the configuration of the circuit portion of the drive system 1 according to Modification 2.

[0124] The control unit 80 includes a controller 81 , a controller 82 , a transfer drive circuit 83 , and a laser drive circuit 84 .

[0125] The controller 81, comprised of a microcomputer and other components, controls various components of the processing apparatus 60. The controller 81 controls the drive mechanism 62 to move the laser unit 61 from the processing start position to the processing end position. Furthermore, the controller 81 controls the laser unit 61 to irradiate the substrate 72 with laser light of an intensity appropriate for the processing.

[0126] The controller 81 detects the current position of the laser unit 61 at each control timing of a given cycle based on the detection signal output from the encoder 64. The controller 81 then generates a control signal for controlling the motor 63 so that the speed of the laser unit 61 at each control timing becomes a preset speed, and outputs the generated control signal to the controller 82.

[0127] The controller 82 is composed of a microcomputer or an FPGA, and corrects the control signal input from the controller 81 based on the image from the camera 20. During this correction, the controller 82 detects the vibration of the detection object TP based on the image from the camera 20 and corrects the control signal to suppress the detected vibration.

[0128] As in the above embodiment, the controller 82 includes an image processing unit 821, a vibration calculation unit 822, and a control signal correction unit 823. The functions of the image processing unit 821, the vibration calculation unit 822, and the control signal correction unit 823 are the same as those of the image processing unit 321, the vibration calculation unit 322, and the control signal correction unit 323 in the above embodiment, with the exception that only one camera 20 is used, the vibration to be detected is only in the X-axis direction, and the control signal is corrected only for the vibration in the X-axis direction.

[0129] That is, the detection target TP is set in the image processing unit 821 by input to the operation terminal 90. The image processing unit 821 extracts the detection target TP from the image of the camera 20 at each control timing and outputs the position of the extracted detection target TP on the image to the vibration calculation unit 822.

[0130] The vibration calculation unit 822 calculates the difference between the input position of the probe object TP and the target position of the probe object TP on the image at the detection time input from the controller 81 as the vibration component of the probe object TP in the X-axis direction.

[0131] When the vibration component input from the vibration calculation unit 822 exceeds the threshold value range Th1 to Th2, the control signal correction unit 823 executes Figure 5 The control signal correction unit 823 corrects the control signal input from the controller 81 and outputs the corrected control signal to the transfer drive circuit 83. If the vibration component input from the vibration calculation unit 822 does not exceed the threshold range Th1 to Th2, the control signal correction unit 823 directly outputs the control signal input from the controller 81 to the transfer drive circuit 83.

[0132] That is, the controller 82 processes the vibration in the X-axis direction in the same way as Figure 6 and Figure 7 Alternatively, the controller 82 may perform the above-mentioned modification example 1 on the vibration in the X-axis direction. Figure 8 Here, a correction signal for accelerating or decelerating the movement of the probe object TP in order to suppress the vibration component is superimposed on the control signal.

[0133] The transfer drive circuit 83 drives the motor 63 based on a control signal input from the controller 82. This allows the laser unit 61 to be moved from the processing start position to the processing end position at a preset speed while suppressing vibration in the X-axis direction. When the vibration is below a predetermined threshold, the laser drive circuit 84 drives the laser unit 61 at a light emission intensity corresponding to the control from the controller 81. In this way, the laser unit 61 is moved at a predetermined speed while emitting laser light of a predetermined intensity, thereby processing the substrate 72.

[0134] In Modification 2, similar to the above-described embodiment, even without attaching an acceleration sensor or the like to the detection target TP of the driven portion, the control signal can be corrected based on the image from the camera 20, thereby suppressing vibrations of the detection target TP. Furthermore, since the image from the camera 20 is used, the detection target can be set to any position on the driven portion without restriction. Consequently, vibrations generated in the detection target TP can be suppressed simply and smoothly.

[0135] <Other Changes>

[0136] In the above embodiment, Figure 5 In the processing, a correction signal having a magnitude and a phase opposite to that of the vibration component A at the control timing D1 is superimposed on the control signal from the controller 31 at the next control timing C1. Alternatively, a correction signal having a magnitude and a phase opposite to that of the vibration component A' obtained by reducing the amplitude of the vibration component A at the control timing D1 by a predetermined ratio (e.g., several percent) may be superimposed on the control signal from the controller 31 at the next control timing C1.

[0137] In addition, Figure 9 In the processing, a correction signal of opposite phase corresponding to the amplitude of the vibration component of the control timing of the white circle, which is increased by a given proportion (for example, a few percent), can also be superimposed on the control signal from the controller 31 at the control timing of the black circle.

[0138] In addition, Figure 5 as well as Figure 9 In the process, the threshold range Th1 to Th2 may be preset in the device or may be set by the user via the operation terminal 40. As described above, the threshold range Th1 to Th2 may be set so that the correction process can be performed using noise instead of vibration components.

[0139] In addition, Figure 5 In the processing, the correction processing is not performed when the vibration component does not exceed the threshold range Th1 to Th2, but it can also be performed based on the fact that the peak value of the vibration component is determined regardless of whether the vibration component exceeds the threshold range Th1 to Th2. Figure 5 However, in this case, as described above, it is also conceivable to perform correction processing using noise instead of vibration. Therefore, in order to stably suppress vibration, it is preferable to perform correction processing when the vibration component exceeds the threshold range Th1 to Th2 as in the above embodiment. Figure 5 Correction processing.

[0140] In addition, in the above embodiment, Figure 4A as well as Figure 4B The target position of the probe object TP used in the vibration calculation process is calculated by the controller 31 based on the transfer trajectory of the hand 12, but the method of obtaining the target position for each control timing is not limited to this. In other words, as long as the normal position of the probe object TP at each control timing (the normal position when there is no vibration component) can be obtained as the target position, the target position can also be obtained from parameter values ​​other than the transfer trajectory of the hand 12. For example, when no vibration component is superimposed on the output from the encoder used to detect the rotation amount of each joint of the robot arm 10, the target position of the probe object TP at each control timing can also be calculated based on the value output from these encoders at each control timing. In addition, the calculation of the target position can be performed by a circuit unit other than the controller 31, such as the controller 32, or by a dedicated circuit unit.

[0141] In addition, in the above embodiment, after the target position on the robot coordinate axis is converted into a position on the image of the camera, the difference between the converted target position and the position on the image of the detection object TP input from the image processing unit 321 is calculated as the vibration component, but conversely, the position on the image of the detection object TP input from the image processing unit 321 can also be converted into a position on the robot coordinate axis, and the difference between the converted position and the target position input from the controller 31 is obtained as the vibration component.

[0142] Furthermore, the method for generating the control signal is not limited to the method described in the above embodiment or Modification 2. For example, the position of a predetermined reference portion of the driven part may be extracted from the images of the cameras 21 and 22, and a control signal may be generated so that the extracted position moves toward the target position along a predetermined movement trajectory.

[0143] Furthermore, while the above embodiments describe the image processing unit, vibration calculation unit, and control signal correction unit separately, it is also possible to combine two or all of these functions into a single unit. For example, the control signal correction unit could also function as the vibration calculation unit. In this case, the vibration calculation unit is omitted from the above configuration, and the position information from the image processing unit is input to the control signal correction unit.

[0144] The number of cameras is not limited to that described in the above embodiment and modifications 1 and 2, and three or more cameras may be used. The cameras are not limited to two-dimensional cameras, and may be three-dimensional cameras that can also detect the distance in the shooting direction.

[0145] In addition, the setting of the detection object TP is not limited to the setting shown in the above embodiment and Modification Example 2, and other parts of the driven part can also be set as the detection object TP. In addition, the application of the technical ideas of the present disclosure is not limited to the drive system of the structure shown in the above embodiment and Modification Example 2, and the technical ideas of the present disclosure can also be appropriately applied to drive systems of other structures.

[0146] The embodiments of the present disclosure can be variously modified as appropriate within the scope of the technical concept shown in the claims.

[0147] (Note)

[0148] The following techniques are disclosed through the description of the above embodiments.

[0149] (Technique 1)

[0150] A driving system comprises: an image processing unit that processes an image from a camera that captures at least the driving range of a driven part to extract a detection object; a vibration calculation unit that calculates a vibration component of the detection object based on the difference between the extracted position of the detection object and the target position of the detection object; and a control signal correction unit that corrects a control signal for driving the driven part using the vibration component, thereby suppressing the vibration of the detection object.

[0151] This technology allows for vibration suppression of the driven object by correcting the control signal based on the camera image, even without attaching a separate accelerometer or other sensor to the driven object. Furthermore, since the camera image is used, the driven object can be positioned anywhere within the driven object without restriction. This allows for simple and smooth suppression of vibrations generated by the driven object.

[0152] (Technique 2)

[0153] In the drive system according to technique 1, the control signal correction unit performs the correction when the vibration component exceeds a predetermined threshold value range, and outputs the control signal without performing the correction when the vibration component does not exceed the threshold value range.

[0154] This technology uses noise rather than vibration components for correction processing, thereby suppressing unintended motion of the probe target. Therefore, vibrations generated in the probe target can be stably suppressed.

[0155] (Technique 3)

[0156] In the drive system described in technology 1 or 2, the vibration calculation unit calculates the vibration component at each control timing of a given period, and the control signal correction unit determines the control timing that is near the peak of the change of the vibration component, and superimposes a correction signal corresponding to the magnitude of the vibration component calculated at the determined control timing on the control signal in an opposite phase to perform the correction.

[0157] According to this technology, by superimposing a correction signal corresponding to the magnitude of the vibration component near the peak with an opposite phase, the vibration energy of the driven part can be effectively eliminated, and the vibration generated by the detection object can be quickly and effectively attenuated. In addition, because the determined control timing is near the peak, the polarity of the vibration component at the next control timing is generally the same as the polarity of the vibration component at the determined control timing. Therefore, even if a correction signal with the opposite polarity of the vibration component obtained at the determined control timing is superimposed on the control signal at the next control timing, the correction signal will not have the effect of further increasing the vibration. Therefore, the vibration of the detection object can be stably suppressed.

[0158] (Technique 4)

[0159] In the drive system described in technology 1 or 2, the vibration calculation unit calculates the vibration component at each control timing of a given cycle, and the control signal correction unit performs the correction at each control timing when the vibration component exceeds a given threshold range.

[0160] This technology, while not able to effectively suppress the vibration of the detected object all at once, can gradually bring the vibration back within the threshold range each time the vibration component exceeds the threshold. Therefore, the vibration of the detected object can be quickly and smoothly suppressed without causing significant vibrations in the drive system.

[0161] (Technique 5)

[0162] In the drive system described in Technology 4, the control signal correction unit performs the correction by superimposing a correction signal corresponding to the magnitude of the vibration component at the control timing when the vibration component exceeds the given threshold range on the control signal in an opposite phase.

[0163] (Technique 6)

[0164] In the driving system according to any one of techniques 1 to 5, an operation terminal for receiving an input from a user is provided, and the image processing unit sets a portion of the driven unit input via the operation terminal as the detection target.

[0165] This technology allows users to arbitrarily set the part (detection target) where they want to suppress vibrations, thereby enabling the drive system to perform vibration suppression control appropriate for the operation of the drive system.

[0166] Industrial applicability

[0167] The drive system disclosed herein can simply and smoothly suppress vibrations generated in a probed object. Consequently, the controllability of the drive system is improved. Thus, the drive system disclosed herein is industrially useful.

[0168] Description of Reference Signs

[0169] 1. Drive system

[0170] 11 Arm (driven part)

[0171] 12 Hand (driven part)

[0172] Cameras 20, 21, and 22

[0173] 40, 90 operation terminals

[0174] 50 items (driven parts)

[0175] 61 Laser unit (driven part)

[0176] 62c Moving member (driven part)

[0177] 321, 821 Image Processing Department

[0178] 322, 822 Vibration calculation unit

[0179] 323, 823 control signal correction unit

[0180] TP detection object

[0181] M1 marker.

Claims

1. A drive system comprising: an image processing unit that processes an image from a camera that captures at least a driving range of the driven part to extract a detection target; a vibration calculation unit that calculates a vibration component of the detection object based on a difference between the extracted position of the detection object and the target position of the detection object; and The control signal correction unit corrects a control signal for driving the driven part using the vibration component, thereby suppressing vibration of the detection object.

2. The drive system according to claim 1, wherein: The control signal correction unit performs the correction when the vibration component exceeds a predetermined threshold value range, and outputs the control signal without performing the correction when the vibration component does not exceed the threshold value range.

3. The drive system according to claim 1, wherein: The vibration calculation unit calculates the vibration component at each control timing of a predetermined cycle. The control signal correction unit determines the control timing near the peak of the change in the vibration component, and performs the correction by superimposing a correction signal corresponding to the magnitude of the vibration component calculated at the determined control timing on the control signal in an opposite phase.

4. The drive system according to claim 1, wherein: The vibration calculation unit calculates the vibration component at each control timing of a predetermined cycle. The control signal correction unit performs the correction at each control timing at which the vibration component exceeds a predetermined threshold value range.

5. The drive system according to claim 4, wherein: The control signal correction unit performs the correction by superimposing a correction signal corresponding to the magnitude of the vibration component at the control timing when the vibration component exceeds the predetermined threshold range on the control signal in an opposite phase.

6. The drive system according to claim 1, wherein: The driving system includes an operation terminal that receives input from a user. The image processing unit sets the portion of the driven part input via the operation terminal as the detection target.

Images