JPH0934552A - Mobile object controller, position detection device, mobile object device and their control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the position of a work piece with high accuracy by detecting the position information on the work out of the images which are photographed by the image pickup devices having the limited resolution. SOLUTION: A part (view field 30 of CCD camera) showing the features of the shape of a work and other parts (view field 31 of CCD camera) of the work are photographed by two CCD cameras which are fixed on the ground. The position relations are previously measured (X0, Y0) among two CCD cameras, a scale 7 and the standard marks 25 and 26 put on the scale 7. A corner C1 is set (X1, Y1) on the basis of the mark 25, and a corner C2 is set (X2, Y2) on the basis of the mark 26 respectively. Then the final target position of the corner C1 is set (X10, Y10). The position (X1, Y1) of the work and the tilt angle θ of a chip set against an axis X are detected based on the position data which are previously measured and also the data on two images which are photographed by both CCD cameras.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body for detecting position information of a work by image processing using a CCD camera, which is a typical image pickup device, and positioning the work on a base member, and a control method thereof. .

[0002]

2. Description of the Related Art Conventionally, when positioning a chip of about 10 mm square on a base member, image processing is performed on one field of view picked up by one CCD camera, and position information X, Y, θ of the chip with respect to the field of view of the CCD camera. Was calculated, and the X-axis, Y-axis, and θ-axis were respectively corrected according to the value to obtain the required accuracy. As such a method, for example, JP-A-3-
Proposals such as No. 228591 have been made.

[0003]

However, according to the above-mentioned conventional method, in order to position the chip with respect to the base member with an accuracy of about ± 1 μm, at least the measurement accuracy of the tilt angle θ of the chip with respect to the X axis is ( A value of the order of 1) is required. (Hereinafter, A∧B means A to the Bth power.) (1 μm / 10 mm) rad = 1 × 10∧-4 rad (1) However, in a general CCD camera, The number of pixels of each is about 500, and the obtained measurement accuracy is
It is only about the formula (2). (1/500) rad≉20 × 10∧-4 rad (2) FIG. 5 is a diagram showing a field of view when a chip is imaged by one CCD camera as the conventional example 1.

As shown in FIG. 5, when the entire chip is placed within the field of view of the CCD camera, the measurement accuracy of the formula (2) is insufficient.

FIG. 6 shows a C having one chip as a conventional example 1.
It is a figure showing the visual field at the time of picturizing with a CD camera.

As shown in FIG. 6, when a part of the chip is placed in the field of view of the CCD camera, the measurement accuracy of θ with respect to the number of pixels of the CCD camera is higher than that in FIG. However, this may occasionally cause problems due to the inability to capture the entire chip.

Further, when a plurality of chips are attached to a base member at a highly accurate pitch of about ± 1 μm, when using a moving body that mounts and moves the base member, the positional information of the moving body is also used. It is necessary to measure with the same accuracy. For that purpose, an expensive measuring device such as a laser length measuring device is required, which causes a cost increase. In addition, the laser length measuring device is also affected by atmospheric pressure and the like, so that there is a drawback that calculation of position information of the moving body becomes complicated.

Further, in a general moving body, when it is moved about 100 mm, it moves about several μm due to yawing in a direction orthogonal to the moving direction, so that a high accuracy of about ± 1 μm is realized and two-dimensional movement is realized. However, it was difficult to position it with the motion system.

Therefore, an object of the present invention is to detect position information of a work from an image picked up by an image pickup device having a limited resolution and to perform highly accurate position detection.

[0010]

As a constitution of the present invention for achieving the above-mentioned object, the first aspect of the present invention is to control a moving body for moving a work to a target position based on image data obtained by picking up the work. In the apparatus, input means for inputting first image data, which is an image of one or more portions representing the shape feature of the work, and one or more other portions, which are image representing the shape feature of the work, are imaged. Input means for inputting the second image data, position data of one or more reference points that are always included in the first and second image data, and position data indicating the relationship between the reference points and the target position. Input means for inputting in advance, and the input position data,
It is a control device for a moving body, comprising a calculating means for calculating a movement amount of the work to the target position based on the first and second image data.

Since there are two image data input means, highly accurate measurement is realized without being limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

2. The control of the moving body according to claim 1, wherein the work in claim 2 is a rectangular object, and the corner portions of the end portions are used as the portions which represent the shape characteristics of the rectangular object. It is a device.

By using the most characteristic part, the structure of image processing can be made relatively simple.

A third aspect of the present invention is an image pickup means for picking up an image of an object,
In a position detecting device equipped with an image processing means for processing the captured image and a detecting means for detecting the position of the object based on the image data obtained by the image processing means, one or more parts representing the characteristics of the shape of the object. A first image pickup means for picking up an image of the object, a second image pickup means for picking up one or more other portions representing the characteristic of the shape of the object, and two images obtained by the first and second image pickup means. Input means for previously inputting the position of one or more reference points that are always included in the data and position data indicating the relationship between the reference point and the target position; the input position data; A position detecting device comprising a detecting means for detecting the position of the object based on one image data.

Since there are two image data input means, highly accurate measurement can be realized without being limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

The object of claim 4 is a rectangular object,
4. The position detecting device according to claim 3, wherein the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object.

By using the most characteristic portion, the structure of image processing can be made relatively simple.

According to a fifth aspect of the present invention, image pickup means for picking up the first and second workpieces, image processing means for processing the picked-up images, and the first data based on the image data obtained by the image processing means.
And a detecting means for detecting the position of the second work, and a moving means for moving the first work to a target position on the second work based on the detected positions of the first and second work. A moving body apparatus including: a first imaging means for imaging one or more portions representing the shape feature of the first work; and one or more others representing the shape feature of the first work. A second image pickup means for picking up an image of a portion of the above, and the positions of one or more reference points that are always included in the two image data obtained by the first and second image pickup means,
Then, the input means for previously inputting position data indicating the relationship between the reference point and the target position, the input position data, and the positions of the first and second works based on the two image data. A mobile device comprising a detection means for detecting.

Since there are two image data input means, highly accurate measurement can be realized without being limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

The movement according to claim 5, wherein the first work of claim 6 is a rectangular object, and the corner portions of the end portions are used as the portions that represent the characteristics of the shape of the rectangular object. It is a body device.

By using the most characteristic part, the structure of image processing can be made relatively simple.

According to a seventh aspect of the present invention, the moving means includes two moving means, a first moving means for moving the first work and a second moving means for moving the second work. The mobile device according to claim 5, wherein:

As a result, it was possible to easily realize the positioning of the plurality of first works arranged side by side on the same second work.

A mobile device according to claim 5, wherein the first and second image pickup means of claim 8 are fixed on the ground or space and do not move.

By securing the reference for positioning, it is possible to easily prevent the image from fluctuating due to the vibration caused by the movement of the second workpiece and the yawing accompanying the movement of the image pickup means.

As another configuration of the present invention for achieving the same object, claim 9 relates to a control method of a control device for a moving body, which moves a work to a target position based on image data obtained by picking up the work. , Inputting first image data obtained by imaging one or more portions representing the shape feature of the work, and obtaining second image data obtained by imaging one or more other portions representing the feature of the work shape. The position data of one or more reference points that are always included in the first and second image data and the position data indicating the relationship between the reference points and the target position are input in advance, and the position data is input. The control method of the control device for a moving body is characterized in that the moving amount of the workpiece to the target position is calculated based on the position data and the first and second image data.

By using two image data input means, highly accurate measurement can be realized without being limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

10. The control of the moving body according to claim 9, wherein the work in claim 10 is a rectangular object, and the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object. It is a method of controlling the device.

The configuration of image processing can be made relatively simple by using the most characteristic part.

According to an eleventh aspect of the present invention, there is provided a method for controlling a position detecting device, wherein an object is imaged, the imaged image is processed, and the position of the object is detected based on image data obtained thereby. , A first imaging step of imaging one or more portions representing the object, a second imaging step of imaging one or more other portions representing the shape feature of the object, and the first and second imaging The positions of one or more reference points that are always included in the two image data obtained by the process,
Then, an input step of previously inputting position data indicating the relationship between the reference point and the target position, and a detection step of detecting the position of the object based on the input position data and the two image data are characterized. Is a control method of the position detecting device.

By using two image data input means, highly accurate measurement can be realized without being limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

The position detecting apparatus according to claim 11, wherein the object of claim 12 is a rectangular object, and the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object. It is a control method.

The configuration of image processing can be made relatively simple by using the most characteristic part.

According to a thirteenth aspect, the first and second workpieces are imaged, the captured images are processed, and the positions of the first and second workpieces are detected based on the image data obtained thereby, In a control method of a moving body device for moving the first work to a target position on the second work based on the detected positions of the first and second works, the shape of the first work A first imaging step of imaging one or more portions representing features, a second imaging step of imaging one or more other portions representing features of the shape of the first workpiece, the first and the second An input step of previously inputting the positions of one or more reference points that are always included in the two image data obtained by the second imaging step, and position data indicating the relationship between the reference points and the target position; , Its input position data and previous Based on the two image data is a control method of the mobile device, characterized in that it comprises a detection step of detecting a position of said first and second workpiece.

By using two image data input means, it is possible to realize high-precision measurement which is not limited by the limited resolution of the image data. Furthermore, since the relationship between the reference point and the target position is input in advance, accurate position detection can be performed even if the entire work cannot fit within the image data area.

The first work according to claim 14 is a rectangular object, and the corner portions of the end portions are used as the portions representing the characteristic features of the shape of the rectangular object.
3 is a method for controlling a mobile device according to item 3.

By using the most characteristic part, the image processing configuration can be made relatively simple.

A fifteenth aspect of the present invention is characterized by comprising two moving steps, a first moving step for moving the first work and a second moving step for moving the second work. A method of controlling a mobile device according to claim 13.

As a result, it was possible to easily realize the positioning of the plurality of first works arranged side by side on the same second work.

The control method for a mobile device according to claim 13 is characterized in that the first and second imaging steps of claim 16 are fixed and not moved in the ground or space.

By ensuring the positioning reference, it is possible to easily prevent the image from fluctuating due to the vibration caused by the movement of the second work and the yawing accompanying the movement of the image pickup means.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment to which the present invention is applied will be described below with reference to the drawings.

First, an apparatus for adhering a work to a base member, which is a moving body to which the present invention is applied, will be described with reference to FIGS.

FIG. 1 is a schematic diagram of the configuration of a chip attaching apparatus as an embodiment of the present invention.

In the figure, the chip attaching apparatus is provided with a finger 3, a θ stage 4, a Y stage 5, and a Z stage 6 on the ceiling, and further an X stage 9, a CCD camera 10 and a CCD camera 11 on the base. The control device 14 controls the chip 1 which is a work to be sequentially attached to the base member 2. The X stage 9, the Y stage 5, and the Z stage 6 are arranged in directions orthogonal to each other.

In the ceiling part, the fingers (vacuum fingers) 3 holding the chip 1 are movable in the Y-axis direction 5 which is the front-back direction of FIG. 1, and in the Z-axis direction which is the vertical direction of FIG. It is mounted so as to be movable and rotatable by a possible Z stage 6 and a θ stage 4 which is rotatable around an axis parallel to the Z axis on the Y stage 5.

At the base, the base member 2 to which the chip 1 is attached is the X stage 9 which is movable in the left-right direction in FIG.
It is movably attached to

Further, the CCD camera 10 and the CCD camera 11 each having the lens 19 and the lens 20 respectively have an illuminating device (not shown) for illuminating the image pickup area, and the base member 2 and the chip 1 as reflected light. Image. Since the chip 1 is attached to the base member 2 with one end protruding from the end face of the base member 2, the CCD camera can be installed below the base member 2. The captured image is binarized by the image processing device 15 and the image processing device 16, and is sent to the control device 14 via the communication means of the communication interface 8. A monitor 17 and a monitor 18 are connected to the image processing device 15 and the image processing device 16, respectively, and a CRT 21 and a keyboard 22 are connected to the control device 14, which are used for programs and maintenance of each device.

Next, the positional relationship among the visual fields 30 and 31, the chip 1, and the base member 2 imaged by the CCD camera will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing the positional relationship around the base member as an embodiment of the present invention.

In the figure, 30 is a visual field imaged by the CCD camera 10, and 31 is a visual field imaged by the CCD camera 11.
The scale 7 is made of a transparent material such as glass, is mounted on the X stage 9 and is movable together with the base member 2, and the reference marks 25 and 26 are plotted on the lower surface of the scale 7. The reference marks are actually plotted on the scale 7 at equal intervals. CCD camera 1
0 and 11 are corners C1 which are the corners of chip 1.
, C2, chip 1, and scale 7 are fixedly arranged so that they are in one visual field. Control device 14
Controls the Y stage 5, the θ stage 4, the X stage 9, and the Z stage 6 based on the position information of the chip 1 calculated based on the reference marks 25 and 26. Further, in reality, the process proceeds in the positional relationship shown in FIG.

FIG. 3 is a diagram showing the positional relationship of the visual fields of two CCD cameras as one embodiment of the present invention.

In the figure, the values of X0 and Y0 are two CCDs.
It is measured in advance because it depends on the position of the camera, the scale 7, and the reference marks 25 and 26 on the scale 7. Corner C
1 is based on the reference mark 25 (X1, Y1), and the corner C2 is based on the reference mark 26 (X2, Y1).
2), and the final target position of the corner C1 is (X1
0, Y10), and the tilt angle of the chip with respect to the X axis is θ.

Next, the flow of processing will be described with reference to FIG.

FIG. 4 is a flowchart of the positioning process as an embodiment of the present invention.

In the figure, in step S1, the finger 3 holding the chip 1 is moved to the position where the CCD camera is in focus.
Move in the direction. Next, in step S2, the control device 14
To send an instruction to the image processing device 15 to calculate (X1, Y1) and send the result to the control device 14. Similarly, in step S3, (X2, Y2) is obtained from the image processing device 16. In step S4, the deviation amount Δθ of the θ stage is calculated. Here, Δθ can be calculated as the expression (3). Δθ = arctan (Y0-Y1 + Y2 / X0-X1 + X2) (3) In step S4, it is determined whether or not the value of Δθ is within a predetermined angular range. If NO, the θ stage 4 is corrected in step S6. Then, the process returns to step S2 and step S3 again. On the other hand, if YES, in step S7,
The movement amounts ΔX and ΔY of the X stage 9 and the Y stage 5 are calculated. Here, when the position of the corner C1 of the chip is positioned at (X10, Y10) with respect to the reference mark 25, Δ
X and ΔY can be calculated by ΔX = X10−X1 ΔY = Y10−Y1. In step S8, the obtained ΔX and ΔY are
It is compared whether it is within a predetermined value range, and if NO, the X stage 9 and the Y stage 5 are corrected in step S9, and the process returns to steps S2 and S3 for confirmation again. YE
If it is S, the finger 3 is lowered to the position of the base member 2 by the Z stage 6 in step S10, and step S
The chip 1 is adhered to the base member 2 by step 11, and step S1
At 2, only the finger 3 is raised to end the series of operations.

By repeating the above-described series of operations each time the X stage 9 is moved at a constant pitch, a plurality of chips can be attached to the base member 2 with high accuracy. <Modification of Embodiment> (1) In the above-described embodiment, two reference marks are used, but since the positional relationship between the two CCD cameras, the scale 7, and the reference marks on the scale 7 is known in advance, one reference is used. You may go by mark. The other configuration is the same as that of the above-described embodiment. (2) In the above embodiment, the θ correction operation and the X and Y correction operations are separately performed in the positioning flowchart, but if the rotation center position of the θ axis is known, Δ
It is also possible to obtain the values of θ, ΔX, and ΔY at the same time and perform the correction operation on two axes simultaneously. The other configuration is the same as that of the above-described embodiment. (3) In the above-described embodiment, the position information is 2 of the chip 1.
Although the corners are used, two pieces of position information that allows image recognition on an object such as a pattern on a chip may be used. The other configuration is the same as that of the above-described embodiment. (4) In the above-described embodiment, two CCD cameras are fixed to the base and the chip 1 and the base member 2 are imaged from the bottom.
If the fingers 3, the θ stage 4, the Y stage 5, and the Z stage 6 on the ceiling are fixed so as not to interfere with the operations, the chip 1 and the base member 2 may be imaged from above. In this case, there is an advantage that the present invention can be applied even when the chip 1 is attached at a position where the chip 1 does not protrude from the base member 2 as in the above embodiment.

The present invention may be applied to either a system composed of a plurality of devices or an apparatus composed of a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device can operate in a predetermined manner.

<Effects of Embodiment> (1) The rotation amount of θ is calculated based on the position information of the two corners C1 and C2 of the rectangular object, which are fetched by the two image processing devices 15 and 16, and at the same time. XY is obtained by the positional information of the reference marks 25 and 26 that enter the visual field.
The amount of movement of the plane was calculated. As a result, it becomes possible to obtain the measurement accuracy required under the environment of the limited resolution of the image processing apparatus, while grasping the overall shape of the chip 1.
High-precision positioning could be easily realized. (2) By making the base member 2 movable together with the X stage 9, a plurality of chip members can be formed on the same base member 2.
It was possible to easily position them side by side. (3) By fixing the CCD cameras 10 and 11 to the base to secure the positioning reference, it is possible to easily prevent the vibration of the X stage 9 from vibrating and the fluctuation of the image due to the yawing accompanying the movement of the CCD camera. It was (4) The measurement accuracy is ensured by the effect (1) of the above-described embodiment, and the reference marks plotted on the scale 7 on the X stage 9 at equal intervals are used as the reference. As a result, it was possible to easily realize highly accurate positioning without newly providing an expensive measuring device such as a laser length measuring device for positioning the X stage 9 for bonding a plurality of chips.

[0060]

As described above, according to the present invention,
It becomes possible to detect the position information of the work from the image picked up by the image pickup device whose resolution is limited and to detect the position with high accuracy.

[0061]

[Brief description of drawings]

FIG. 1 is a schematic diagram of a configuration of a chip attaching apparatus as an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship around a base member as an embodiment of the present invention.

FIG. 3 is a diagram showing a positional relationship of fields of view of two CCD cameras as one embodiment of the present invention.

FIG. 4 is a flowchart of a positioning process as an embodiment of the present invention.

FIG. 5 is a diagram showing a field of view when a chip is imaged by one CCD camera as Conventional Example 1.

FIG. 6 is a diagram showing a field of view when a chip is imaged by one CCD camera as Conventional Example 1.

[Explanation of symbols]

 1 chip 2 base member 3 finger 4 θ stage 5 Y stage 6 Z stage 7 scale 8 communication interface 9 X stage 10 CCD camera 11 CCD camera 14 control device 14 15 image processing device 16 image processing device 17 monitor 18 monitor 19 lens 20 Lens 21 CRT 22 Keyboard 25 Reference mark 26 Reference mark 30 Field of view imaged by the CCD camera 10 31 Field of view imaged by the CCD camera 11

Claims (16)

[Claims] 1. A control device for a moving body, which moves a work to a target position based on image data of the work, wherein a first image of one or more portions representing the shape feature of the work is picked up. Input means for inputting data, input means for inputting second image data of one or more other portions representing the shape feature of the work, and always included in the first and second image data Like 1
Based on the input means for inputting in advance the position of one or more reference points and the position data indicating the relationship between the reference points and the target position, and the input position data and the first and second image data. A control device for a moving body, comprising: a calculating unit that calculates the amount of movement of the workpiece to the target position. 2. The control apparatus for a moving body according to claim 1, wherein the work is a rectangular object, and the corner portions of the end portions are used as the portions that represent the shape characteristics of the rectangular object. 3. A position detecting device comprising an image pickup means for picking up an object, an image processing means for processing the picked up image, and a detecting means for detecting the position of the object based on the image data obtained by the image processing means. First imaging means for imaging one or more portions representing the shape characteristics of the object; second imaging means for imaging one or more other portions representing the shape characteristics of the object; An input for previously inputting the positions of one or more reference points that are always included in the two image data obtained by the first and second imaging means, and position data indicating the relationship between the reference points and the target position. A position detecting device comprising: means and a detecting means for detecting the position of the object based on the input position data and the two image data. 4. The position detecting device according to claim 3, wherein the object is a rectangular object, and corner portions of an end portion are used as a portion representing the shape feature of the rectangular object. 5. Image pickup means for picking up images of the first and second works, image processing means for processing the picked-up images, and positions of the first and second works based on image data obtained thereby. Detecting means for detecting, and the detected first
And a moving body device including a moving means for moving the first work to a target position on the second work based on the position of the second work, the shape feature of the first work is expressed. A first imaging means for imaging one or more portions, a second imaging means for imaging one or more other portions representing the shape feature of the first workpiece, the first and second Input means for inputting in advance the position of one or more reference points that are always included in the two image data obtained by the image pickup means, and position data indicating the relationship between the reference points and the target position; A mobile device, comprising: detecting means for detecting the positions of the first and second workpieces based on the generated position data and the two image data. 6. The first work is a rectangular object,
6. The moving body apparatus according to claim 5, wherein the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object. 7. The moving means comprises two moving means, a first moving means for moving the first work and a second moving means for moving the second work. The mobile device according to claim 5. 8. The first and second imaging means are fixed on the ground or space and do not move.
The mobile device described. 9. A control method of a control device for a moving body, which moves a work to a target position based on image data of the work, in which one or more portions representing the feature of the shape of the work are imaged. The first image data is input, the second image data obtained by capturing one or more other portions representing the shape feature of the workpiece is input, and the second image data is always included in the first and second image data. 1
Positions of one or more reference points and position data indicating the relationship between the reference points and the target position are input in advance, and the work is based on the input position data and the first and second image data. A method of controlling a control device for a moving body, comprising: calculating the amount of movement of the vehicle to the target position. 10. The control device for a moving body according to claim 9, wherein the work is a rectangular object, and the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object. Control method. 11. A control method of a position detecting device, which captures an image of an object, processes the imaged image, and detects the position of the object based on image data obtained thereby. A first imaging step of imaging one or more parts; a second imaging step of imaging one or more other parts representing the shape feature of the object; and a first imaging step and a second imaging step. An input step of previously inputting the positions of one or more reference points that are always included in the two image data that are stored, and position data indicating the relationship between the reference points and the target position; and the input position data. And a detection step of detecting the position of the object based on the two image data, a method for controlling a position detection device. 12. The method for controlling a position detecting device according to claim 11, wherein the object is a rectangular object, and the corner portions at the ends are used as the portions representing the shape characteristics of the rectangular object. . 13. The first and second workpieces are imaged, the captured images are processed, the positions of the first and second workpieces are detected based on image data obtained thereby, and the detected images are detected. A method of controlling a moving body device for moving the first work to a target position on the second work based on the positions of the first and second works, wherein the shape feature of the first work is represented. A first imaging step of imaging one or more parts, a second imaging step of imaging one or more other parts representing the shape feature of the first workpiece, the first and second An input step of previously inputting the positions of one or more reference points that are always included in the two image data obtained by the imaging step, and position data indicating the relationship between the reference points and the target position; Location data and the two The method of the mobile device characterized by comprising a detection step of detecting a position of said first and second workpiece based on image data. 14. The moving body apparatus according to claim 13, wherein the first work is a rectangular object, and the corner portions of the end portions are used as the portions representing the shape characteristics of the rectangular object. Control method. 15. The method according to claim 13, further comprising a first moving step of moving the first work piece and a second moving step of moving the second work piece. A method for controlling a mobile device described. 16. The method of controlling a mobile device according to claim 13, wherein the first and second imaging steps are fixed and do not move on the ground or in space.