Device and method for obtaining tool operation position offset

Abstract

The present invention provides a device and method for obtaining the offset of a tool working position, which can obtain the offset of the working position of the tool relative to the target position of a workpiece with high precision according to the actual operation. The device obtains the offset of the working position of the tool relative to the target position when the tool is moved by a mobile machine and the tool is used to operate the target position of the workpiece, and the device comprises: a camera, which is configured in a predetermined positional relationship relative to the tool and photographs the target position at the first moment when the tool performs an action for operation; and an offset acquisition unit, which obtains the offset between the working position and the target position at the first moment based on the position of the target position in the image data captured by the camera and information indicating the position of the working position in the image data.

Description

Technical Field

[0001] The invention relates to a device and a method for obtaining an offset of a working position of a tool relative to a target position of a workpiece. Background Art

[0002] There is a known prior art that uses a camera to capture the target position of the workpiece and corrects the teaching point of the robot based on the captured image data in order to eliminate the deviation of the working position of the tool relative to the target position of the workpiece (for example, Japanese Patent Application Laid-Open No. 2009-125839).

[0003] There is a need for a technology for acquiring the deviation of the working position of a tool with respect to the target position of a workpiece with high accuracy based on actual work. Summary of the invention

[0004] In one embodiment of the present disclosure, there is provided a device for obtaining an offset of a working position of a tool relative to a target position when a tool is moved by a mobile machinery and the tool is used to perform an operation on a target position of a workpiece. The device comprises: a camera, which is configured in a predetermined positional relationship relative to the tool and photographs the target position at the first moment when the tool performs an action for the operation; and an offset acquisition unit, which obtains the offset between the working position and the target position at the first moment based on the position of the target position in image data captured by the camera and information indicating the position of the working position in the image data.

[0005] In another embodiment of the present disclosure, a method is provided for obtaining an offset of a working position of a tool relative to a target position when a tool is moved by a mobile machinery and the tool is used to perform an operation on a target position of a workpiece. The method uses a camera that is configured in a predetermined positional relationship relative to the tool to photograph the target position at the first moment when the tool performs an action for the operation, and based on the position of the target position in the image data captured by the camera and information indicating the position of the working position in the image data, the offset between the working position and the target position at the first moment is obtained.

[0006] According to the present disclosure, the operator does not need to measure the deviation between the target position on the workpiece and the working position estimated as the actual working position of the tool on the workpiece based on image data, but can automatically and accurately obtain the deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a block diagram of a mechanical system of one embodiment.

[0008] Figure 2 yes Figure 1 A schematic diagram of the mechanical system shown.

[0009] Figure 3 yes Figure 2 A magnified view of the tool is shown.

[0010] Figure 4 is a schematic diagram of the artifacts of one embodiment.

[0011] Figure 5 Shows Figure 3 An example of image data captured by the camera shown.

[0012] Figure 6 Another example of the positional relationship between the tool and the camera is shown.

[0013] Figure 7 Shows Figure 6 An example of image data captured by the camera shown.

[0014] Figure 8 Another example of the positional relationship between the tool and the camera is shown.

[0015] Fig. 9 Shows Figure 8 An example of image data captured by the camera shown.

[0016] Fig.10 is a block diagram of a mechanical system according to another embodiment.

[0017] Fig.11 yes Fig.10 A magnified view of the tool, camera and light irradiation device shown.

[0018] Fig.12 Shows Fig.11 An example of image data captured by the camera shown.

[0019] Fig.13 Shows Figure 3 Another example of image data captured by the camera shown.

[0020] Fig.14 Shows Figure 3 Another example of image data captured by the camera shown.

[0021] Fig.15 is an enlarged view of a tool according to another embodiment.

[0022] Fig.16 This is an enlarged view of a tool according to yet another embodiment.

[0023] Fig.17 Shows Fig.16 The tool shown is in a state where a part is fitted into a hole.

[0024] Fig.18The camera is set to Fig.16 The status of the tool is shown.

[0025] Fig.19 Shows Fig.18 An example of image data captured by the camera shown.

[0026] Fig. 20 is a block diagram of a mechanical system according to yet another embodiment.

[0027] Fig.21 is a block diagram of a mechanical system according to yet another embodiment. DETAILED DESCRIPTION

[0028] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. In addition, in the various embodiments described below, the same elements are marked with the same symbols and repeated descriptions are omitted. Figure 1 to Figure 3 A mechanical system 10 according to one embodiment will be described. The mechanical system 10 includes a control device 12 , a mobile machine 14 , a tool 16 , and a camera 17 .

[0029] The control device 12 is a computer having a processor (CPU, GPU, etc.) 18 and a storage unit (ROM, RAM, etc.) 20, and controls the mobile machine 14, the tool 16, and the camera 17. The processor 18 and the storage unit 20 are connected to each other via a bus 19 so as to be able to communicate with each other, and communicate with the storage unit 20 to perform various operations.

[0030] like Figure 2 As shown, the mobile machine 14 is a vertical multi-joint robot, which has a base 22, a rotating body 24, a lower arm 26, an upper arm 28 and a wrist 30. The base 22 is fixed to the ground of the working unit. The rotating body 24 is arranged on the base 22 in a manner that can rotate around a vertical axis. The lower arm 26 is arranged on the rotating body 24 in a manner that can rotate around a horizontal axis.

[0031] The upper arm 28 is rotatably provided at the front end of the lower arm 26. The wrist 30 is rotatably provided at the front end of the upper arm 28. A plurality of servo motors 31 ( Figure 1 The processor 18 sends instructions to the servo motors 31 , and the servo motors 31 drive the movable elements of the mobile machine 14 (ie, the swing body 24 , the lower arm 26 , the upper arm 28 , and the wrist 30 ).

[0032] The tool 16 is mounted on the wrist 30. In this embodiment, the tool 16 is a spot welding gun. Figure 3As shown, the tool 16 includes a base portion 32 , a fixed arm 34 , a movable arm 36 , a servo motor 38 , a fixed electrode 44 , and a movable electrode 46 .

[0033] The base 32 is connected to the wrist 30. The base end 40 of the fixed arm 34 is fixed to the base 32, and a fixed electrode 44 is fixed to the front end 42 of the fixed arm 34. In this embodiment, the fixed arm 34 extends from the base end 40 to the front end 42 in a substantially L-shape.

[0034] The movable arm 36 is provided on the base portion 32 so as to be movable along the axis A (so-called gun axis). In the present embodiment, the movable arm 36 is a rod-shaped member extending linearly, and its upper end portion (not shown) is mechanically connected to an output spindle (not shown) of the servo motor 38 via a motion conversion mechanism 48, and a movable electrode 46 is fixed to the lower end of the movable arm 36.

[0035] The motion conversion mechanism 48 includes, for example, a ball screw mechanism or a mechanism composed of a timing belt and a pulley, and converts the rotational motion of the output spindle of the servo motor 38 into reciprocating motion along the axis A. The movable arm 36 reciprocates along the axis A by the servo motor 38 via the motion conversion mechanism 48 .

[0036] The fixed electrode 44 and the movable electrode 46 are arranged to be aligned on the axis A. As the servo motor 38 moves the movable arm 36, the movable electrode 46 moves along the axis A in a manner of approaching and moving away from the fixed electrode 44. The fixed electrode 44 and the movable electrode 46 are energized according to the command from the processor 18. Thus, the workpiece clamped between the fixed electrode 44 and the movable electrode 46 can be spot welded.

[0037] like Figure 2 As shown, a mobile machine coordinate system C is set for the mobile machine 14. M . Mobile mechanical coordinate system C M It is a control coordinate system (so-called robot coordinate system) for automatically controlling each movable element of the mobile machine 14. M With respect to the mobile machine 14, the mobile machine coordinate system C M The origin of the moving machine coordinate system C is configured at the center of the base portion 22. M The z-axis is parallel to the vertical direction of the real space, and the rotating body 24 can move around the mechanical coordinate system C M The z-axis rotation.

[0038] On the other hand, Figure 3 As shown, the tool coordinate system C is set for the tool 16. T The tool coordinate system C TIt is a control coordinate system for automatically controlling the position of the tool 16 in three-dimensional space. In addition, in this case, the "position" sometimes refers to the position and posture. In this embodiment, the tool coordinate system C T Relative to the tool 16, the tool coordinate system C T The origin of the tool coordinate system C is located on the fixed electrode 44 (e.g., the center of the upper surface). T The z-axis is consistent with (or parallel to) axis A.

[0039] The processor 18 causes each movable element of the mobile machine 14 to move in the mobile machine coordinate system C M The tool 16 is moved in such a way that the position of the tool 16 is consistent with the tool coordinate system C T In this way, the tool 16 can be moved by the mobile machine 14 and configured in the mobile machine coordinate system C M Any position in .

[0040] The camera 17 has an imaging sensor such as a CCD or CMOS, an optical system such as a focusing lens, and is arranged in a predetermined positional relationship relative to the tool 16. Figure 3 As shown in FIG. 1 , the movable electrode 46 is arranged at a position such that the sight line direction D of the camera 17 is aligned with the axis A (i.e., the tool coordinate system C T The z-axis of Figure 3 In the illustrated state, the movable arm 36 is stationarily arranged at a predetermined position in the direction of the axis A (eg, a retracted position farthest from the fixed electrode 44 ).

[0041] The camera 17 captures an image of an object along the line of sight D, and supplies the captured image data to the control device 12. A camera coordinate system C is set for the camera 17. C . Camera coordinate system C C The coordinate system C is a coordinate system that specifies the coordinates of each pixel of the image data captured by the camera 17. Each pixel of the image data captured by the camera 17 is in the camera coordinate system C C Central coordinates.

[0042] Next, refer to Figure 1 to Figure 4 The work performed by the tool 16 is described. Figure 4 The multiple target positions B set on the workpiece W shown in FIG. n (n=1, 2, 3, ...) spot welding is performed. The workpiece W is, for example, a sheet metal for a car body. The processor 18 operates the moving machine 14 so that the tool 16 is disposed at the nth teaching point C n , the nth teaching point C n For the nth target position B n Perform spot welding work.

[0043] Specifically, the processor 18 converts the tool coordinate system C T The origin is configured at the nth teaching point C n , and set it as the tool coordinate system C T The z-axis passes through the nth target position B n Furthermore, the processor 18 causes the mobile machine 14 to move so that the position of the tool 16 is aligned with the tool coordinate system C T The specified position is consistent.

[0044] In this way, the processor 18 places the tool 16 at the nth teaching point C n When the tool 16 is placed at the nth teaching point C n When the nth target position B n It is arranged between the movable electrode 46 and the fixed electrode 44. n Can be compared with the nth target position B n Consistent, it is also possible to start from the nth target position B n Start in a predetermined direction (for example, tool coordinate system C T Separated in the negative direction of the z-axis).

[0045] The processor 18 causes the tool 16 to be placed at the nth teaching point C n The servo motor 38 of the tool 16 is driven to move the movable electrode 46 so as to approach the fixed electrode 44, so as to move the workpiece W to the nth target position B. n The processor 18 may place the tool 16 at the nth teaching point C. n At this time, the operation of bringing the movable electrode 46 closer to the fixed electrode 44 begins.

[0046] As an alternative, the processor 18 may also cause the tool 16 to move to the nth teaching point C n During the movement, the movable electrode 46 starts to approach the fixed electrode 44. When the workpiece W is sandwiched between the movable electrode 46 and the fixed electrode 44, the nth target position B n When the processor 18 energizes the movable electrode 46 and the fixed electrode 44, the nth target position B n The processor 18 performs spot welding on all target positions B n Repeat this spot welding operation.

[0047] The processor 18 executes a series of actions for such spot welding according to the operation program. The operation program can be used to teach the mobile machine 14 to position the tool 16 at the nth teaching point C. n The operation program includes: the nth teaching point Cn Position information (moving machine coordinate system C M coordinates in ), used to position the tool 16 at the nth teaching point C n A positioning instruction for causing the movable electrode 46 and the fixed electrode 44 to perform spot welding, and the like.

[0048] Here, when the processor 18 performs the operation according to the operating program, the nth target position B is sandwiched between the movable electrode 46 and the fixed electrode 44. n During the operation of the movable electrode 46 and the fixed electrode 44, the actual working position of the contact with the workpiece W may be changed from the nth target position B n Deviation. Such deviation is caused, for example, by the following reasons: when the tool 16 is moved by the mobile machine 14, the tool 16 is slightly vibrated due to acceleration and deceleration, and the deviation is caused by the slight vibration.

[0049] Therefore, in this embodiment, the processor 18 obtains the working position of the tool 16 relative to the nth target position B n The following is an explanation of the operation of obtaining the offset in the mechanical system 10. As a preparatory stage for the operation of obtaining the offset, the operator moves the workpiece W to the nth target position B n Additional markings.

[0050] The mark is, for example, an engraving, a seal, or a coating provided on the workpiece W, and is used to make the nth target position B n It is visually displayed in the image captured by the camera 17. In addition, when the nth target position B n The marking may be omitted when there are identifiable features (corners, recesses, etc.).

[0051] After the workpiece W is set at a predetermined position relative to the mobile machine 14, the processor 18 operates the mobile machine 14 according to the operation program so that the tool 16 moves to the nth teaching point C. n Furthermore, the processor 18 causes the tool 16 to execute the operation for moving the nth target position B n The time τ of spot welding operation n , so that the camera 17 is positioned at the nth target position B n Take photos.

[0052] As an example, the time τ at which the camera 17 takes the image is n The timing is set so that the movable electrode 46 and the fixed electrode 44 of the tool 16 abut against the workpiece W. The timing at which the movable electrode 46 and the fixed electrode 44 abut against the workpiece W is predictable. Specifically, the processor 18 receives a welding start instruction according to the operation program, and sends an instruction to the servo motor 38 to move the movable electrode 46 toward the fixed electrode 44.

[0053] The time τ from when the processor 18 sends a command to the servo motor 38 to when the servo motor 38 moves the movable electrode 46 and sandwiches the workpiece W between the movable electrode 46 and the fixed electrode 44 x The time τ at which the movable electrode 46 and the fixed electrode 44 come into contact with the workpiece W can be predicted based on the acceleration and deceleration characteristics of the servo motor 38. n It can be set as the time τ that has passed since the processor 18 sent a command to the servo motor 38. x moment.

[0054] As another example, the time τ at which the camera 17 takes the image is n It can be set as the time when the processor 18 receives the welding start instruction according to the operation program and sends the instruction for moving the movable electrode 46 to the servo motor 38. As another example, the time τ when the camera 17 takes the image n The timing at which the movable electrode 46 and the fixed electrode 44 holding the workpiece W are energized can be set. The energization timing is, for example, the timing at which the processor 18 sends a voltage supply instruction to a voltage source (not shown) (or the timing after a predetermined time has passed from this timing), and the voltage source supplies voltage to the movable electrode 46 and the fixed electrode 44. The timing τ at which the camera 17 is used to capture the image n Determined by the operator.

[0055] In addition, in the present embodiment, the processor 18 at this time τ n The movable electrode 46 is not actually moved toward the fixed electrode 44. For example, the processor 18 may be configured to not actually send a command to the servo motor 38 to move the movable electrode 46, but only recognize the timing of sending the command. Alternatively, the processor 18 may send a dummy command to the servo motor 38 that does not actually move the servo motor 38.

[0056] Figure 5 It shows that the camera 17 is at time τ n This is an example of converting captured image data into images. Figure 5 The image data 60 shown shows the nth target position B on the workpiece W. n In addition, for reference Figure 5 In FIG. 1 , the fixed electrode 44 located on the back side of the workpiece W is indicated by a dotted line, and the tool coordinate system C is shown. T .

[0057] As described above, in this embodiment, the camera 17 is arranged so that the line of sight D coincides with the axis A. At this time, the fixed electrode 44 (or the tool coordinate system C) is arranged at the center of the image data 60. TTherefore, the center point (the pixel at the center) of the image data 60 can be n It is considered that in actual spot welding work, when the movable electrode 46 is moved toward the fixed electrode 44 , the movable electrode 46 and the fixed electrode 44 come into contact with the workpiece W and sandwich the workpiece W.

[0058] The storage unit 20 stores the camera coordinate system C C The center point F n The coordinates of are stored as information indicating the position of the work position in the image data 60. In the image data 60, the nth target position B n From the center point (i.e. the working position of the tool 16) F n From the camera coordinate system C C The positive x-axis direction is offset by the difference x C , and is offset in the positive direction of the y axis by the difference y C In other words, in the image data 60, the nth target position B n From the working position F n The difference E c (|E c |=(x C 2 +y C 2 ) 1 / 2 ). In addition, these differences x C , difference y C Sum and Difference E c is a vector.

[0059] The processor 18 analyzes the image data 60 obtained from the camera 17 and obtains the image data indicating the nth target position B n A pixel (for example, the nth target position B n The pixel at the center of the image area) in the camera coordinate system C C Then, the processor 18 uses the camera coordinate system C C The nth target position B in n The coordinates of the pre-stored operation position (center point) F n The coordinates of the camera coordinate system C C The difference x C Sum and difference y C (or difference E c ), and use the difference x C Sum and difference y C (or difference E c ), and tool coordinate system C T With the camera coordinate system C C The known position relationship is used to obtain the tool coordinate system C T The work position Fn and the nth target position B n The offset between .

[0060] Here, the camera 17 and the tool 16 are arranged in a known positional relationship with each other, and thus the tool coordinate system C is represented by T With the camera coordinate system C C The parameters of the first transformation matrix (eg, homogeneous transformation matrix) of the positional relationship can be obtained by transforming the tool coordinate system C T and the camera coordinate system C C Through this calibration, the tool coordinate system C T The coordinates of the camera coordinate system C C The coordinates of are transformed into each other via a first transformation matrix.

[0061] The processor 18 uses the first transformation matrix to transform the camera coordinate system C C The difference x C Sum and difference y C , or difference E c Transform to tool coordinate system C T The offset x in T and the offset y T , or offset E T These offsets x T , offset y T , offset E T is a vector. In this way, the processor 18 can obtain the n The tool coordinate system C T The work position F n and the nth target position B n The offset x between T and the offset y T (or offset E T ).

[0062] As described above, the processor 18 determines the nth target position B based on the nth target position B. n The position in the image data 60 and the work position F n The position set in the image data 60 is obtained at the time τ n Working position F n and the nth target position B n The offset x between T and the offset y T (or offset E T ). Therefore, in the present embodiment, the processor 18 functions as the offset acquisition unit 52.

[0063] The offset x obtained in this way T and the offset yT (or offset E T ) is not to place the tool 16 at the nth teaching point C n The target position B at the moment n With the working position F n The offset is not the offset, but accurately represents the time τ when the tool 16 performs the action for the spot welding operation (for example, the command to the servo motor 38, the contact between the movable electrode 46 and the workpiece W, and the energization of the movable electrode 46 and the fixed electrode 44). n The target position B n With the working position F n The offset data.

[0064] Next, the processor 18 calculates the offset x based on the obtained offset x. T and the offset y T (or offset E T ) to correct the position of the mobile machine 14 so that at time τ n Set the working position F n Configured at the nth target position B n For example, Figure 5 In the example shown, the processor 18 automatically sets the nth teaching point C specified in the operation program to n Corrected to tool coordinate system C T The x-axis negative direction moves by an offset x T , to the tool coordinate system C T The positive y-axis direction moves by an offset y T Alternatively, the processor 18 sets the nth teaching point C n Corrected to the tool coordinate system C T Only the offset E is moved T location.

[0065] In this way, the processor 18 processes the nth teaching point C included in the operation program. n The position information of the mobile machine 14 is corrected, thereby updating the operation program. Therefore, the processor 18 is used as the position of the mobile machine 14 (the nth teaching point C n ) is corrected by a position correction unit 54 ( Figure 1 ) to perform its function.

[0066] As described above, in this embodiment, by n For the nth target position B n The camera 17 for shooting and the offset x T , offset y T , offset E T The offset acquisition unit 52 acquires the working position F of the tool 16. nRelative to the nth target position B n The offset x T , offset y T , offset E T Therefore, the camera 17 and the offset acquisition unit 52 constitute the device 50 ( Figure 1 ), the device 50 obtains the working position F of the tool 16 n Relative to the nth target position B n The offset x T , offset y T , offset E T .

[0067] According to the device 50, it is not necessary for the operator to determine the nth target position B on the workpiece W based on the image data 60. n , and the working position F where the tool 16 is estimated to actually work on the workpiece W n The offset x between T , offset y T , offset E T By measuring, the offset x can be automatically and accurately calculated. T , offset y T , offset E T .

[0068] In addition, in the present embodiment, the storage unit 20 constitutes the device 50 and stores the camera coordinate system C in advance. C The center point F n The coordinates of the work position F are stored as n The information of the position in the image data 60. According to this structure, it is not necessary to check the working position F every time. n The position is set and detected, so the offset x can be quickly obtained with a relatively simple algorithm. T , offset y T , offset E T .

[0069] In the present embodiment, the position correction unit 54 constitutes the device 50 and is based on the acquired offset x T and the offset y T (or offset E T ) for the position of the mobile machine 14 (the nth teaching point C n According to this structure, the processor 18 can more accurately adjust the working position F of the tool 16 when executing a series of actions of the spot welding operation according to the updated operation program. n (The sandwiching position of the movable electrode 46 and the fixed electrode 44) is arranged at the target position B n In addition, it can save the operator from manually adjusting the teaching point C.n The correction work is performed, thereby reducing the teaching work on the mobile machine 14.

[0070] In this embodiment, the processor 18 functions as the offset acquisition unit 52 to obtain the camera coordinate system C C The difference x C Sum and difference y C (or difference E c ), and use the difference x C Sum and difference y C (or difference E c ), and tool coordinate system C T With the camera coordinate system C C The known positional relationship (specifically, the first transformation matrix) of the tool coordinate system C is obtained. T The offset x in T and the offset y T (or offset E T According to this structure, the offset x in the control coordinate system can be obtained more accurately based on the image data 60. T and the offset y T (or offset E T ).

[0071] In addition, in this embodiment, the camera 17 is arranged at a position on the movable electrode 46 so that the line of sight D of the camera 17 coincides with the axis A (i.e., the z-axis of the tool coordinate system). n The working position F of the configuration tool 16 n .

[0072] According to this configuration, the operator can intuitively grasp the working position F when viewing the image data 60. n From the nth target position B n The offset distance and direction. In addition, in the tool coordinate system C T and the camera coordinate system C C When performing calibration, only the parameters of the line of sight direction D (z-axis of the tool coordinate system) need to be considered, thereby simplifying the calibration work.

[0073] In addition, the installation position of the camera 17 is not limited to Figure 3 The manner shown (i.e. the position of the movable electrode 46). Figure 6 Another example of the installation position of the camera 17 relative to the tool 16 is described below. Figure 6 In the illustrated embodiment, the camera 17 is mounted on the base portion 32 via a mounting fixture 62 , and is disposed in a predetermined positional relationship with respect to the tool 16 .

[0074] Specifically, the camera 17 is fixed relative to the tool 16 so that the sight direction D of the camera 17 is parallel to the axis A and deviates from the axis A by a predetermined distance, and the fixed electrode 44 is included in the field of view of the camera 17 . Figure 7 Shows that Figure 6 The camera 17 is shown at the time τ at which the tool 16 performs the action for the spot welding operation. n For the nth target position B n This is an example of converting captured image data into images.

[0075] exist Figure 7 In the image data 64 shown, when the movable electrode 46 is moved toward the fixed electrode 44 during the actual spot welding operation, the movable electrode 46 and the fixed electrode 44 abut against the workpiece W and clamp the workpiece W at the operation position F. n (or tool coordinate system C T The origin of the image data 64 is offset from the center of the image data 64 (ie, the line of sight direction D).

[0076] The work position F in the image data 64 at this time n The position of can be determined based on the camera 17 (specifically, the line of sight D) and the tool 16 (specifically, the fixed electrode 44, or the tool coordinate system C T The storage unit 20 stores the camera coordinate system C in advance. C The work position F n The coordinates of the work position F are stored as n Information about the position in the image data 64 .

[0077] The processor 18 analyzes the image data 64 captured by the camera 17 and obtains the image data representing the nth target position B. n A pixel in the camera coordinate system C C and use the coordinates and the pre-stored work position F n The coordinates of the camera coordinate system C C The difference x C Sum and difference y C (or difference E c ).

[0078] here, Figure 6 The camera 17 and tool 16 are shown arranged in a known positional relationship with each other, so that Figure 6 The tool coordinate system C in T With the camera coordinate system C C The parameters of the second transformation matrix (eg, homogeneous transformation matrix) of the positional relationship can be obtained by transforming the tool coordinate system C TThe tool coordinate system C can be corrected by calibrating the camera coordinate system. T The coordinates of the camera coordinate system C C The coordinates of are transformed into each other via a second transformation matrix.

[0079] The processor 18 uses the second transformation matrix to transform the camera coordinate system C C The difference x C Sum and difference y C , or difference E c Transform to tool coordinate system C T The offset x in T and the offset y T , or offset E T In this way, the processor 18 can obtain n Working position F n and the nth target position B n The offset x between T and the offset y T (or offset E T ).

[0080] Figure 8 Another example of the installation position of the camera 17 relative to the tool 16 is shown. Figure 8 In the illustrated embodiment, the camera 17 is fixed relative to the tool 16 in such a position that the sight line D of the camera 17 is inclined at a predetermined angle θ relative to the axis A and the fixed electrode 44 is included in the field of view of the camera 17 . Fig. 9 Shows that Figure 8 The camera 17 is shown at the time τ at which the tool 16 performs the action for the spot welding operation. n For the nth target position B n This is an example of converting captured image data into images.

[0081] Fig. 9 Working position F shown n (or tool coordinate system C T The position of the origin of the image data 66 can be determined based on the positional relationship between the camera 17 and the tool 16. For example, when the camera 17 is configured relative to the tool 16 so that the line of sight D of the camera 17 passes through the tool coordinate system C T In the case of the positional relationship of the origin, the center point F of the image data 66 can be n Considered as working position F n The storage unit 20 stores the camera coordinate system C C The work position F n The coordinates of the work position F are stored as n Information about the position in the image data 66 .

[0082] The processor 18 analyzes the image data 66 captured by the camera 17 and obtains the image data representing the nth target position B. n A pixel in the camera coordinate system C C and use the coordinates and the pre-stored work position F n The coordinates of the camera coordinate system C C The difference x C Sum and difference y C (or difference E c ).

[0083] Figure 8 The camera 17 and tool 16 are shown arranged in a known positional relationship with each other, so that Figure 8 The tool coordinate system C in T With the camera coordinate system C C The parameters of the third transformation matrix (eg, homogeneous transformation matrix) of the positional relationship can be obtained by T The tool coordinate system C can be corrected by calibrating the camera coordinate system. T The coordinates of the camera coordinate system C C The coordinates of are transformed into each other via a third transformation matrix.

[0084] The processor 18 uses the third transformation matrix to transform the camera coordinate system C C The difference x C Sum and difference y C , or the difference Ec is transformed into the tool coordinate system C T The offset x in T and the offset y T , or offset E T In this way, the processor 18 can obtain n Working position F n and the nth target position B n The offset x between T and the offset y T (or offset E T ).

[0085] Next, refer to Fig.10 and Fig.11 A mechanical system 70 according to another embodiment will be described. The mechanical system 70 is different from the mechanical system 10 described above in that it further includes a light irradiation device 72. In addition, the positional relationship between the camera 17 and the tool 16 in this embodiment is the same as that in the embodiment shown in FIG. Figure 6 The same method is shown.

[0086] The light irradiation device 72 is, for example, a laser pointer, which outputs light (such as laser) that travels in a straight line along the optical axis O. The light irradiation device 72 is disposed on the movable electrode 46 so that the optical axis O of the light irradiation device 72 is aligned with the axis A (or the tool coordinate system C). T The z-axis of Fig.11 In the illustrated state, the movable arm 36 is stationarily arranged at a predetermined position in the direction of the axis A (eg, a retracted position farthest from the fixed electrode 44 ).

[0087] Next, the offset x is obtained in the mechanical system 70 T , offset y T , offset E T The processor 18 operates the movable machine 14 according to the operation program in the same manner as in the above-mentioned embodiment, so that the tool 16 moves to the nth teaching point C n Move, and at the time τ that the tool 16 performs the action for the spot welding operation n , using the camera 17 to detect the nth target position B which can be identified by a mark or the like n Take photos.

[0088] Here, in this embodiment, the processor 18 uses the camera 17 to detect the nth target position B. n Before photographing, the light irradiation device 72 is operated so that the light irradiation device 72 outputs light. Fig.12 It shows that at time τ n This is an example of converting image data captured by the camera 17 into images. Fig.12 The image data 84 shown also shows the nth target position B on the workpiece W. n And light 86 irradiated toward the surface of the workpiece W from the light irradiation device 72 .

[0089] The light irradiation device 72 is arranged such that its optical axis O is aligned with the axis A (tool coordinate system C T Therefore, the position of the light 86 in the image data 84 represents the working position F where the movable electrode 46 and the fixed electrode 44 abut against and clamp the workpiece W during the actual spot welding operation. n .

[0090] The processor 18 obtains a pixel representing the light 86 in the image data 84 (eg, a pixel at the center of the image area of ​​the light 86) in the camera coordinate system C. C The coordinates in the work position F are used as n The information of the position in the image data 84 is stored in the storage unit 20. In addition, the processor 18 analyzes the image data 84 captured by the camera 17 and obtains the information indicating the nth target position B. nA pixel in the camera coordinate system C C In addition, the processor 18 uses the work position F obtained from the light 86 shown in the image data 84 n The coordinates of the nth target position B n The coordinates of the camera coordinate system C C The difference x C Sum and difference y C (or difference E c ).

[0091] And, the processor 18 uses the representation Fig.11 The tool coordinate system C in T With the camera coordinate system C C The second transformation matrix of the position relationship transforms the camera coordinate system C C The difference x C Sum and difference y C , or difference E c Transform to tool coordinate system C T The offset x in T and the offset y T , or offset E T In this way, the processor 18 can obtain n Working position F n and the nth target position B n The offset x between T and the offset y T (or offset E T ).

[0092] In this embodiment, the camera 17, the storage unit 20, the offset acquisition unit 52, the position correction unit 54, and the light irradiation device 72 constitute a device 80 ( Fig.10 ), the device 80 obtains the working position F of the tool 16 n Relative to the nth target position B n The offset x T , offset y T , offset E T Furthermore, when the camera 17 captures the image data 84, the light irradiation device 72 irradiates the workpiece W with light indicating the working position F. n of light.

[0093] According to this embodiment, it is not necessary to prepare in advance a display of the working position F n By using the information of the position in the image data 84, it is possible to automatically obtain the information indicating the working position F from the light 86 shown in the image data 84. n The information of the position in the image data 84 (i.e., the pixel representing the light 86 in the image data 84 in the camera coordinate system C) Ccoordinates in ).

[0094] In addition, in the above embodiment, the camera 17 may further be configured to capture the image at the time τ n The time τ of the advance time t n -t, or compared to time τ n Delay time t at the moment τ n +t for the nth target position B n In other words, the camera 17 can also capture the moment τ n Multiple moments in time τ n -t, τ n , τ n +t for the nth target position B n The image capture (ie, video capture) is performed continuously at a period t. The period t of the continuous image capture can be determined according to the optical specifications of the camera 17 and the like.

[0095] The following is for Figure 3 In the embodiment shown, the camera 17 is at time τ n -t, τ n and τ n +t for the nth target position B n A case where shooting is performed continuously will be described. Fig.13 It shows that at time τ n -t for the nth target position B n This is an example of converting captured image data into images. Fig.14 It shows that at time τ n +t for the nth target position B n This is an example of converting captured image data into images. Fig.13 and Fig.14 The nth target position B is shown as a white dot G for reference. n exist Figure 5 The position in the image data 60 is shown.

[0096] like Fig.13 As shown, when the camera 17 is at time τ n -t In the image data 90 captured, the nth target position B n From the center point (i.e., the working position) of the image data 90, n From the camera coordinate system C C The positive x-axis direction is offset by the difference x C ' and shifted to the positive direction of the y axis by the difference y C '. In other words, the nth target position B n From the working position F n The difference E c '(|Ec '|=(x C ' 2 +y C ' 2 ) 1 / 2 ).

[0097] The processor 18 can obtain the camera coordinate system C by the above method. C The difference x C 'Sum difference y C ', or difference E c ', and use the first transformation matrix to transform the camera coordinate system C C The difference x C 'Sum difference y C ', or difference E c 'Transform to tool coordinate system C T The offset x in T ' and offset y T ', or offset E T ', get the n -t's working position F n and the nth target position B n The offset x between T ' and offset y T '(or offset E T ').

[0098] On the other hand, Fig.14 As shown, when the camera 17 is at time τ n In the image data 92 captured by +t, the nth target position B n From the center point of the image data 92 (i.e., the working position) F n From the camera coordinate system C C The positive x-axis direction is offset by the difference x C " and shifted in the positive direction of the y-axis by a difference y C In other words, the nth target position B n From the working position F n The difference E c ”(|E c ”|=(x C ” 2 +y C ” 2 ) 1 / 2 ).

[0099] The processor 18 can obtain the camera coordinate system C by the above method. C The difference x C " and the difference y C ", or difference E c ", and use the first transformation matrix to transform the camera coordinate system CC The difference x C " and the difference y C ", or difference E c "Transformed into tool coordinate system C T The offset x in T " and offset y T ", or offset E T ”, obtain the n +t working position F n and the nth target position B n The offset x between T " and offset y T ” (or offset E T ”). This allows the offset to be n -t, τ n , τ n In this embodiment, the processor 18 performs the following operations at different times τ: n -t, τ n , τ n +t gets the offset.

[0100] Here, the actual size (e.g., thickness) of the workpiece W as the work object may vary. If the size of the workpiece W varies, the timing when the movable electrode 46 and the fixed electrode 44 contact and clamp the workpiece W during the actual spot welding operation will also vary according to the size.

[0101] For example, suppose that the nominal dimension of the thickness of the workpiece W is a0, the dimensional tolerance is ±0.1, and the time τ n is the moment when the movable electrode 46 and the fixed electrode 44 contact the workpiece W with a nominal dimension a0. At this time, when the workpiece W with an actual dimension a0+0.1 (i.e., thicker than the nominal thickness dimension a0) is clamped by the movable electrode 46 and the fixed electrode 44, the moment when the movable electrode 46 and the fixed electrode 44 contact the workpiece W is greater than the moment τ n Ahead of time.

[0102] On the contrary, when the workpiece W having an actual thickness dimension of a0-0.1 (i.e., thinner than the nominal thickness dimension a0) is clamped by the movable electrode 46 and the fixed electrode 44, the moment when the movable electrode 46 and the fixed electrode 44 contact the workpiece W is shorter than the moment τ n Therefore, when the actual thickness dimension of the workpiece W is thinner or thicker than the nominal thickness dimension a0, even at the time τ n For the nth target position B n Shooting is performed, and the nth target position B in the image data at this time nThe positions of the movable electrode 46 and the fixed electrode 44 at the time when they come into contact with the workpiece W may not be shown.

[0103] Therefore, in this embodiment, the camera 17 is used to capture the image at multiple different times τ n -t, τ n , τ n +t for the nth target position B n Continuous shooting (animation shooting) is performed, and the processor 18 obtains the offset x for each of the acquired plurality of image data 60, 90, 92: T and the offset y T (or offset E T ), offset x T ' and offset y T '(or offset E T '), offset x T " and offset y T ” (or offset E T ”).

[0104] For example, if we set the time τ n -t corresponds to the time when the movable electrode 46 and the fixed electrode 44 come into contact with the workpiece W having a size of a0+0.1, and the time τ n +t corresponds to the moment when the movable electrode 46 and the fixed electrode 44 contact the workpiece W with a size of a0-0.1, and the processor 18 can respectively obtain: the offset x related to the workpiece W with a nominal size of a0 T and the offset y T (or offset E T ), the offset x related to the workpiece W with the nominal size a0 ± dimensional tolerance T ' and offset y T '(or offset E T ') and the offset x T " and offset y T ” (or offset E T ”).

[0105] By doing this at multiple moments τ n -t, τ n , τ n +t acquires the offset amount by acquiring the image data 60 , 90 , 92 captured, thereby acquiring the offset amount corresponding to the deviation in the size of the workpiece W. As an example, the processor 18 may generate the image of Table 1 below and display it on a display (not shown) provided on the control device 12 .

[0106]

[0107] Table 1

[0108] The operator can analyze the working position F of the tool 16 based on statistics by referring to Table 1 and taking into account the dimensional tolerance. n Relative to the nth target position B n In addition, although in this embodiment, as an example, the camera 17 is n -t, τ n , τ n +t for the nth target position B n The case of performing imaging is described above, but it is also possible to include the time τ corresponding to the workpiece W with the nominal size a0. n The nth target position B is n Continuous shooting is performed to analyze the offset more specifically.

[0109] In addition, although the tool 16 is described as a spot welding gun in the above embodiment, the tool is not limited to a spot welding gun. Fig.15 A tool 96 according to another embodiment will be described. The tool 96 emits laser light along the optical axis P and is disposed at a working position F. n A laser processing head for laser processing the workpiece W. The tool 96 is mounted on the wrist 30 of the mobile machine 14 instead of the tool 16 described above.

[0110] The processor 18 sends a laser oscillation command to a laser oscillator (not shown) provided outside the tool 96, and the laser oscillator supplies laser light to the tool 96 through a light guide path such as an optical fiber. The tool 96 emits laser light from an emission port 96a along an optical axis P, and uses the laser light to perform laser processing (laser cutting, laser welding, etc.) on the workpiece W. A tool coordinate system C is set for the tool 96. T In this embodiment, the tool coordinate system C T With respect to the tool 96, the tool coordinate system C T The origin of the tool coordinate system C is located at the center of the exit port 96a. T The z-axis is consistent with (or parallel to) the optical axis P.

[0111] The processor 18 is for example directed to Figure 4 The nth target position B on the workpiece W is shown n Specifically, the processor 18 operates the movable machine 14 so that the tool 96 is disposed at the nth teaching point C n , the nth teaching point C n For the nth target position B n Execute laser processing. At this time, the processor 18 converts the tool coordinate system C T The origin is configured at the nth teaching point Cn , and set it as the tool coordinate system C T The z-axis (i.e., optical axis P) passes through the nth target position B n .

[0112] Then, the processor 18 sends a laser oscillation instruction to the laser oscillator, and the laser is emitted from the tool 96 and the laser is used to perform a laser operation at the working position F. n Laser processing is performed on the workpiece W. That is, the working position F in this embodiment n This is the position where the tool 96 irradiates the workpiece W with laser light (or the intersection of the optical axis P and the surface of the workpiece W).

[0113] The processor 18 processes all target positions B n Such laser processing is repeatedly performed. The processor 18 executes a series of actions for such laser processing according to the operation program. The operation program is pre-stored in the storage unit 20. The operation program includes: n-th teaching point C n The position information is used to position the tool 96 at the nth teaching point C n Positioning instructions for the laser oscillator, laser oscillation instructions for the laser oscillator, etc.

[0114] The processor 18 places the tool 96 at the nth teaching point C according to the operation program. n , so that when the laser is output from the tool 96, the working position F at which the laser is actually irradiated on the workpiece W is n It is possible to go from the nth target position B n Therefore, the device 50 obtains the working position F of the tool 96 in the same manner as in the above embodiment. n Relative to the nth target position B n The offset of

[0115] like Fig.15 As shown, the camera 17 of the device 50 is arranged in a predetermined positional relationship relative to the tool 96. Specifically, the camera 17 is arranged at the exit 96a of the tool 96 so that the sight direction D of the camera 17 is aligned with the optical axis P (i.e., the tool coordinate system C T The z-axis of the

[0116] When obtaining the offset, the processor 18 operates the mobile machine 14 according to the operation program so that the tool 96 moves to the nth teaching point C n Furthermore, the processor 18 sends an instruction to the camera 17, which uses the camera 17 to cause the tool 96 to execute the operation for moving the nth target position B. n The time τ of the laser processing operation n For the nth target position B n Take photos.

[0117] As an example, the time τ in this embodiment n It can be set as the time when the processor 18 sends the laser oscillation instruction to the laser oscillator. As another example, the time τ n It can be set to the time when the laser light is actually emitted from the tool 96. The time τ from the time when the processor 18 sends a laser oscillation instruction to the laser oscillator to the time when the tool 96 actually emits the laser light. y It can be predicted based on the specifications of the laser oscillator, etc. Therefore, the time τ at which the laser is actually emitted from the tool 96 is n It can be set as the time τ that has passed since the laser oscillation instruction was sent to the laser oscillator. y moment.

[0118] Thus, the camera 17 is at time τ n Shooting as Figure 5 The nth target position B is shown as shown n In the present embodiment, the camera 17 is arranged relative to the tool 96 so that the sight line direction D of the camera 17 coincides with the optical axis P. Therefore, the center point (center pixel) F of the captured image data 60 can be n The working position F where the laser is irradiated onto the workpiece W during the actual laser processing operation is considered to be n Furthermore, the processor 18 can function as the offset acquisition unit 52, Figure 3 Similarly, the offset x is obtained according to the image data 60. T and the offset y T (or offset E T ). And, the processor 18 and Figure 3 In the same manner as in the embodiment of FIG. 1 , the position correction unit 54 functions based on the offset x T and the offset y T (or offset E T ) For the nth teaching point C n Make corrections.

[0119] In addition, Fig.15 In the embodiment shown, the camera 17 can be arranged relative to the tool 96 in the following positional relationship, that is, the sight direction D of the camera 17 is parallel to the optical axis P, and the sight direction D deviates from the optical axis P by a predetermined distance. Figure 6 The same method is shown in the implementation to obtain the offset x T and the offset y T (or offset E T ).

[0120] As an alternative, in Fig.15In the embodiment shown, the camera 17 can be arranged relative to the tool 96 in the following positional relationship, that is, the line of sight D of the camera 17 is inclined at a predetermined angle θ relative to the optical axis P. At this time, the processor 18 can use Figure 8 The same method is shown in the implementation to obtain the offset x T and the offset y T (or offset E T ).

[0121] Next, refer to Figure 16 to Figure 18 A tool 98 according to another embodiment will be described. The tool 98 is a tool for the nth part I n (n=1, 2, 3, ...) and hold the workpiece W so that it is aligned with the nth hole H formed on the workpiece W. n The embedded robot. The nth part I n It is a rod-shaped (e.g., cylindrical) component having a central axis Q. In addition, the nth hole H n The nth target position B formed on the workpiece W n and has a central axis R n For example, the nth target position B n It can be defined as the nth hole H on the surface of the workpiece W n The opening center. At this time, the axis R n Passing the nth target position B n .

[0122] The tool 98 is installed on the wrist 30 of the mobile machine 14 instead of the tool 16 described above. Specifically, the tool 98 includes a hand base 100 connected to the wrist 30, a plurality of fingers 102 provided on the hand base 100 so as to be openable and closable, and a driving unit 104 for opening and closing the plurality of fingers 102. The driving unit 104 is, for example, an air cylinder or an electric motor, and can grip and release an object by opening and closing the fingers 102.

[0123] Tool coordinate system C is set for tool 98 T In this embodiment, the tool coordinate system C T With respect to the tool 98, the tool coordinate system C T The origin of the tool coordinate system C is located at the holding position of the finger 102 (or between multiple fingers 102). T The z-axis is orthogonal to the opening and closing direction of the finger 102 .

[0124] Next, refer to Fig.16 and Fig.17The fitting operation performed by the tool 98 is described below. The workpiece W may be fixed at a predetermined position by a fixture or the like, or may be moved by a conveyor or the like. The processor 18 operates the moving machine 14 and uses the tool 98 to fit the nth part I stored in a predetermined storage location. n At this time, the tool 98 is in the tool coordinate system C T The nth part I is held in a manner that the z-axis is aligned with the axis Q n .

[0125] Next, the processor 18 operates the movable machine 14 to place the tool 98 at the nth teaching point C n , the nth teaching point C n Used to execute the nth part I n With the nth hole H n Specifically, the processor 18 converts the tool coordinate system C T Set its origin to be at the nth teaching point C n , and the tool coordinate system C T The z-axis (i.e., axis Q) and the nth hole H n Axis R n Roughly the same.

[0126] Then, the processor 18 operates the mobile machine 14 so that the position of the tool 98 is aligned with the tool coordinate system C T As a result, the tool 98 and the nth part I held by the tool 98 are aligned. n Relative to the workpiece W Fig.16 Next, the processor 18 sends a mating start command to the mobile machine 14. Then, the mobile machine 14 moves the tool 98 to the tool coordinate system C T The z-axis moves in the negative direction so that the nth part I held by the tool 98 n With the nth hole H n As a result, Fig.17 As shown, the tool 98 is used to make the nth part I n With the nth hole H n Chimera.

[0127] The processor 18 repeatedly performs such an embedding operation, so that the plurality of parts 1 n Respectively with a plurality of holes B n The processor 18 executes a series of actions for such a fitting operation according to the operation program. The operation program includes: the nth teaching point C n The position information is used to position the tool 98 at the nth teaching point C n Positioning instructions, fitting start instructions, etc.

[0128] Here, the processor 18 performs the operation according to the operating program to make the nth part I n With the nth hole H n During the mating operation, the nth part I n The working position for engaging with the workpiece W may be from the nth hole H n (i.e. the nth target position B n ) offset. Therefore, in this embodiment, the device 50 is similar to the above-mentioned embodiment, and obtains the working position of the tool 98 relative to the nth target position B n The offset of

[0129] like Fig.18 As shown, the camera 17 of the device 50 is held by the tool 98 (or fixed to the tool 98) in a manner that is arranged in a predetermined positional relationship relative to the tool 98. Specifically, the camera 17 is arranged so that its line of sight D is aligned with the nth part I held by the tool 98. n Axis Q (or tool coordinate system C T The z-axis of the

[0130] When obtaining the offset, the processor 18 operates the mobile machine 14 according to the operation program so that the tool 98 moves to the nth teaching point C n Furthermore, the processor 18 sends an instruction to the camera 17, which uses the camera 17 to cause the tool 98 to execute a motion relative to the nth target position B. n (The nth hole H n ) of the embedded operation action time τ n For the nth target position B n Take photos.

[0131] As an example, the time τ in this embodiment n It can be set as the time when the processor 18 sends the fitting start instruction to the mobile machine 14. As another example, the time τ n It can be set as the nth part I held by the tool 98 n Engaged with workpiece W (or nth part I n The moment when the front end reaches the surface of the workpiece W.

[0132] From the time when the processor 18 sends the mating start command to the time when the nth part I is held by the tool 98 n Time τ until engagement with workpiece W z The prediction can be made based on the acceleration and deceleration characteristics of the servo motor 31 of the mobile machine 14. n The moment of engagement with the workpiece W nIt can be set so that the time τ has passed since the mating start command was sent. z moment.

[0133] Thus, the camera 17 is at time τ n For the nth target position B n (The nth hole H n ) to shoot. Fig.19 An example of converting the image data captured by the camera 17 at this time into an image is shown. Fig.19 The image data 106 shown shows the nth hole H formed on the workpiece W. n As an example, the processor 18 analyzes the image data 106 and detects the nth hole H n The center point of the detected center point is obtained in the camera coordinate system C C The coordinates in are used as the nth target position B n In the camera coordinate system C C The coordinates in .

[0134] In addition, in the present embodiment, the camera 17 is arranged relative to the tool 98 in a positional relationship in which the sight line direction D of the camera 17 coincides with the axis Q (z axis of the tool coordinate system), so that the center point (center pixel) F of the captured image data 106 can be n Considered as the nth part I in the actual fitting operation n Working position F for engaging with workpiece W n .

[0135] Furthermore, the processor 18 can function as the offset acquisition unit 52 and use the camera coordinate system C C The nth target position B in n and the working position F n Find the difference x of the coordinates C Sum and difference y C (or difference E c ),and Figure 3 In the embodiment shown, the offset x is obtained according to the image data 106. T and the offset y T (or offset E T ). And, the processor 18 and Figure 3 The embodiment of the present invention also functions as the position correction unit 54, based on the offset x T and the offset y T (or offset E T ) For the nth teaching point C n Make corrections.

[0136] In addition, Fig.18In the embodiment shown, the camera 17 can be arranged relative to the tool 98 in the following positional relationship, that is, the line of sight D of the camera 17 and the axis Q (tool coordinate system C C The z-axis of the axis Q is parallel to the axis Q, and the line of sight D deviates from the axis Q by a predetermined distance. Figure 6 The same method is shown in the implementation to obtain the offset x T and the offset y T (or offset E T ).

[0137] As an alternative, in Fig.18 In the embodiment shown, the camera 17 can be arranged relative to the tool 98 in the following positional relationship, that is, the line of sight D of the camera 17 is inclined at a predetermined angle θ relative to the axis Q. At this time, the processor 18 can use Figure 8 The same method is shown in the implementation to obtain the offset x T and the offset y T (or offset E T ).

[0138] In the above embodiment, the control device 12 controls the mobile machine 14 and the tool 16, 96 or 98. However, the present invention is not limited thereto, and the control device 12 may control the mobile machine 14, and another control device other than the control device 12 may control the tool 16, 96 or 98.

[0139] Fig. 20 This approach is shown.

[0140] Fig. 20 The mechanical system 110 shown includes: a control device 12, a mobile machine 14, a tool 16, 96 or 98, a camera 17, and a second control device 112. The second control device 112 is connected to the control device 12 in a communicable manner. The second control device 112 includes: a processor 114 and a storage unit 20 connected to the processor 114 in a communicable manner via a bus 116. The processor 114 controls the tool 16, 96 or 98. The processor 114 functions as the offset acquisition unit 52 and the position correction unit 54 of the device 50. In addition, the processor 114 sends a command to the camera 17 to control the shooting action of the camera 17.

[0141] In addition, the offset acquisition unit 52 may be provided separately from the control device 12 or 112 . Fig.21 This approach is shown. Fig.21The mechanical system 120 shown includes: the control device 12, the mobile machine 14, the tool 16, 96 or 98, and the device 122. The device 122 is similar to the above-mentioned device 50, and obtains the working position of the tool 16, 96 or 98 relative to the nth target position B. n The camera 17 is connected to the control device 12 and is provided with an offset acquisition unit 52 and a camera 17. n For the nth target position B n The offset acquisition unit 52 may be composed of a computer having a processor and a storage unit.

[0142] In addition, in the above-mentioned embodiment, the processor 18 converts the camera coordinate system C C The difference x C Sum and difference y C Or difference E c Transform to tool coordinate system C T The offset x in T and the offset y T Or the offset E T However, the processor 18 may also convert the camera coordinate system C C The difference x C Sum and difference y C , or difference E c Transform to mobile machine coordinate system C M (or world coordinate system).

[0143] For example, the processor 18 may also calculate the tool coordinate system C T After the offset in, the tool coordinate system C T The offset in is transformed into the mobile mechanical coordinate system C M (or world coordinate system). Alternatively, the operator can also pre-set the camera coordinate system C C and mobile mechanical coordinate system C M (or world coordinate system) is corrected, and the processor 18 converts the camera coordinate system C C The difference x C , difference y C , Difference E c Transform to mobile machine coordinate system C M (or world coordinate system), thereby obtaining the mobile mechanical coordinate system C M (or world coordinate system).

[0144] In addition, the tool coordinate system C T The position relative to the tool 16, 96 or 98 is not limited to the above-mentioned embodiment and can be any position. Figure 3 , Figure 6or Figure 8 In the embodiment shown, the processor 18 may also use the camera 17 to detect the nth target position B n The movable arm 36 is moved when photographing. As mentioned above, the present disclosure has been described by using the embodiment, but the above-mentioned embodiment does not limit the invention of the claims.

Claims

1. A device for obtaining a displacement of a working position of a tool relative to a target position when a tool is moved by a mobile machine and the tool is used to work on a target position of a workpiece, The device is characterized in that it has: Processor; and a camera arranged in a predetermined positional relationship relative to the tool, The processor identifies, based on the work program, a time to send a command for causing the tool to perform an action for the work, At a first moment which is the time of the transmission or a time after a predetermined time has passed from the time of the transmission, the camera is caused to capture the target position, while the tool is not caused to perform the actual action. The offset between the working position and the target position at the first moment is acquired based on the position of the target position in the image data captured by the camera and information indicating the position of the working position in the image data.

2. The device according to claim 1, characterized in that The device further includes a storage unit for pre-storing the information.

3. The device according to claim 1, characterized in that A light irradiation device is further provided, the light irradiation device being provided on the tool and irradiating light for indicating the working position to the workpiece when the camera captures the image data. The processor acquires the offset using the position of the light in the image data as the information.

4. The device according to any one of claims 1 to 3, characterized in that The tool is a welding gun having a fixed electrode and a movable electrode, the movable electrode moving along an axis in a manner of approaching and moving away from the fixed electrode, When performing the operation, the tool abuts against the workpiece at the operation position. The command is a command for moving the movable electrode, or a command for supplying a voltage in order to energize the fixed electrode and the movable electrode.

5. The device according to any one of claims 1 to 3, characterized in that: The tool is a laser processing head that emits laser light along an optical axis. The instructions are instructions for generating the laser.

6. The device according to any one of claims 1 to 3, characterized in that: The tool is a robot that holds the part and fits the part into a hole set at the target position. The instruction is an instruction for moving the tool toward the hole by the moving machine.

7. The device according to claim 4, characterized in that The camera is configured so that the sight direction of the camera is consistent with the axis.

8. The device according to claim 5, characterized in that The camera is configured so that the sight direction of the camera is consistent with the optical axis.

9. The device according to claim 1, characterized in that The processor causes the tool not to perform the actual action by not sending the instruction or sending a virtual instruction.

10. The device according to any one of claims 1 to 3, characterized in that: The processor corrects the position of the mobile machine based on the acquired offset so that the working position is arranged at the target position at the first time.

11. The device according to any one of claims 1 to 3, characterized in that: The processor calculates a difference between the target position and the work position in the camera coordinate system using the coordinates of the target position in the camera coordinate system that defines the coordinates of the image data and the coordinates of the work position in the camera coordinate system. The offset in the control coordinate system is acquired using a known positional relationship between a control coordinate system set for the tool or the mobile machine and the camera coordinate system and the difference.

12. A device for obtaining a displacement of a working position of a tool relative to a target position when a tool is moved by a mobile machine and the tool is used to work on a target position of a workpiece, The device is characterized in that it has: a camera arranged in a predetermined positional relationship with respect to the tool and photographing the target position at a first moment of causing the tool to perform an action for the operation, the first moment being a moment of sending an instruction for causing the tool to perform the action, or a moment after a predetermined time has passed since the sending moment; and an offset acquisition unit that acquires an offset between the working position and the target position at the first moment based on the position of the target position in the image data captured by the camera and information indicating the position of the working position in the image data, The camera also photographs the target position at a second time before or after the first time. The offset acquisition unit also acquires a second offset between the tool and the target position at the second moment based on the position of the target position in the second image data captured by the camera at the second moment and information indicating the position of the working position in the second image data.

13. A method for obtaining an offset of a working position of a tool relative to a target position when a tool is moved by a mobile machine and the tool is used to work on a target position of a workpiece, The method is characterized in that The processor identifies, based on the work program, a time to send an instruction for causing the tool to perform an action for the work, At a first moment which is the moment of the sending or a moment after a predetermined time has passed from the moment of the sending, a camera which is arranged in a predetermined positional relationship with respect to the tool is caused to photograph the target position, while the tool is not caused to actually perform the action. The offset between the working position and the target position at the first moment is acquired based on the position of the target position in the image data captured by the camera and information indicating the position of the working position in the image data.

Images