JP2002113679A - Tracking method, system, and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tracking method, tracking system, and tracking device capable of supplying works quickly and certainly better than in a conventional arrangement. SOLUTION: An output means of this tracking device emits photographing signals continuously so that the photographing region by a photographing means and the photographing region directly following it overlap in the advancing direction with a certain width in which the whole figure of a work processed can be accommodated, and a visually acknowledging means of an image processing device photographs the specified photographing region on the basis of the photographing signal emitted from the output means, and acknowledgement is made for the position coordinates of only the work whose whole figure is accommodated within the applicable photographing region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking method for imaging a plurality of works conveyed by a carrier and controlling the handling of the plurality of works based on the position coordinates of each work recognized from the imaging result. , A tracking system, and a tracking device.

[0002]

2. Description of the Related Art A conventional tracking system 10 will be described below.
0 will be described with reference to FIG. FIG. 1A is a plan view showing the entire configuration of the tracking system 100, and FIG. 1B is a front view of the same system. As shown in FIG. 1, a tracking system 100 includes a conveyor 25 for transporting a work placed irregularly, and a CCD camera 11 for photographing a plurality of workpieces carried by the conveyor 25 from above in a predetermined imaging area. A visual recognition unit 112 (not shown) for recognizing the position, shape, and the like of the work from the imaging information; and a visual recognition unit 112 arranged downstream of the first conveyor 25a, based on the position and shape of the work recognized by the visual recognition unit 112. The robot controller 20 and the like hold the work in a predetermined holding area, and transfer and align the work on the pallet P.

[0003] As such a conventional tracking system, for example, as disclosed in Japanese Patent Application Laid-Open No. 8-323669, a work located on a boundary line on the downstream side of the imaging region is included in the next imaging region. A component supply method and an apparatus for continuously recognizing the position, posture, and the like of all the works on a conveyor by determining each imaging region as described above are known.

[0004]

However, every time the CCD camera 11 captures an image of a workpiece, the visual recognition unit 112 obtains the position coordinates of each workpiece from the image information of all the workpieces in the imaging area including the workpiece on the boundary line. And shape, etc.
It has been determined whether or not the work is located on the boundary line based on the recognition result. Further, when a work exists on the boundary line, the imaging area is moved by a predetermined distance to a position where the entire shape of the work is included in the subsequent imaging area.

[0005] For this reason, especially when a large number of works exist on the boundary line, the time for determining the presence or absence of the work located on the boundary line and the distance between the preceding and succeeding imaging regions (hereinafter, referred to as “imaging pitch”). Not only does the time required for image acquisition, such as the calculation time, increase, but work recognition omission sometimes occurs.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide a tracking method, a tracking system, and a tracking device for supplying a work at a higher speed and more reliably than before.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to an imaging step (for example, steps S3 and S8) for imaging a plurality of works carried by a carrier in a predetermined imaging area. ), A coordinate acquisition step of acquiring position coordinates of each work from the imaging result, and a tracking step of controlling handling of the plurality of works based on the position coordinates (for example, steps S10 to S1).
1) in the tracking method, wherein the imaging area in the imaging step (for example, steps S3 and S8) and the imaging area immediately following the imaging area overlap in the traveling direction with a constant width that accommodates the entire shape of the work. An output step of continuously outputting an image signal (for example, step S6), and a visual recognition step of recognizing only the position coordinates of the work including the entire shape in the image area (for example, steps S4 and S9). It is characterized by.

Here, for example, a configuration may be added in which a process of automatically recognizing the shape of the work in the visual recognition process and calculating the major axis is added. Further, the transport speed may be varied according to the number of workpieces transporting the transport body per unit time.

According to the first aspect of the present invention, since the front and rear imaging regions overlap with a width that can accommodate the entire shape of the work,
There is no missing work recognition, and there is no need to recognize the work on the boundary of the imaging area at the time of imaging. In addition, since the imaging pitch before and after is always kept constant, it is not necessary to calculate the imaging pitch and perform variable control of the imaging area at the time of imaging. Therefore, the image processing time can be reduced, and the omission of recognition of the work can be reduced. Further, it is possible to increase the transport speed of the transport body, and it is possible to improve the tracking processing ability.

According to a second aspect of the present invention, a plurality of works (for example, works 3) conveyed by a carrier (for example, a conveyor 25) are imaged by an imaging means (for example, a CCD camera 11), and the imaging is performed. In a tracking system (for example, the tracking system 1) including: an image processing device that acquires position coordinates of each work from a result; and a tracking device that controls handling of the plurality of works based on the position coordinates. The tracking device (for example, the tracking device 20)
An output unit (for example, an output unit that continuously outputs an imaging signal such that an imaging region of the imaging unit and an imaging region immediately after the imaging unit overlap in a traveling direction with a constant width that accommodates the entire shape of the work (for example,
A CPU 21), and the image processing apparatus (for example,
The image processing apparatus 10) captures an image of a predetermined imaging region based on the imaging signal output from the output unit, and recognizes only the work including the entire shape in the imaging region. Recognition unit 12).

Therefore, the invention described in claim 1 can be realized as a tracking system.

Further, according to a third aspect of the present invention, there is provided image information of a plurality of works (for example, works 3) acquired by an image pickup means (for example, CCD camera 11) of an image processing apparatus (for example, image processing apparatus 10). In the tracking device (for example, the tracking device 20) that controls the handling of the plurality of works based on the position coordinates of each work recognized from the camera, the imaging region of the imaging unit and the imaging region immediately after the imaging device are the entire region of the work. An output means (for example, CPU 21) for continuously outputting an image signal so as to overlap in the traveling direction with a constant width in which the shape can be accommodated is provided.

Therefore, the invention described in claim 1 can be realized as a tracking device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tracking system 1 according to a preferred embodiment of the present invention will be described below with reference to the drawings.

First, the configuration will be described with reference to FIGS. FIG. 1 is a schematic view of a tracking system 1 according to the present embodiment, in which (a) is a plan view and (b) is a front view. The overall structure of the tracking system 1 according to the present embodiment is the same as that of the tracking system 1 shown in FIG. 1 in the above-described conventional technology. And illustration thereof will be omitted.

FIG. 2 is a block diagram showing a main configuration of the tracking system 1 according to the present embodiment.
As shown in FIG. 2, the image processing apparatus 10 includes a CCD camera 11, a visual recognition unit 12, an image acquisition control unit 13, and a work arrival detection sensor 14.

The CCD (Charge Coupled Device) camera 11 is, for example, an industrial television camera (ITV).
Image information is acquired using the visible region on the conveyor 25 shown in FIG. 4 as an imaging region. In FIG. 4, “L” is the width of the visible region in the x-axis direction, and “a” is the x of the overlapping portion of each imaging region.
It is a constant value representing the width in the axial direction.

The visual recognition unit 12 determines only the shadow of the work 3 that matches the value obtained by including an error in the work data 23a stored in the storage device 23 in advance from the work 3 in the imaging area. It is extracted as information, and image information of a work located on the boundary of the imaging region (that is, a work that does not include the entire shape in the imaging region) is not acquired. Also,
The visual recognition unit 12 performs, for example, a process such as pattern matching based on the acquired image information, calculates the barycentric position coordinates (x, y) of each work, and uses the calculation result as position coordinate data to perform image acquisition control. Output to the unit 13.

The image acquisition control unit 13 determines the timing of taking image information into the visual recognition unit 12 according to the input signal transmitted from the CPU 21 according to the transport distance of the conveyor 25. The workpiece arrival detection sensor 14 is a conveyor 2
When one end of the work 3 conveyed by 5 reaches the boundary line of the imaging region, it outputs a reaching signal to the image acquisition control unit 13. The display unit 15 (not shown) is, for example, an LCD.
(Liquid Crystal Display) and the image acquisition control unit 1
According to the instruction of 3, the image information obtained from the CCD camera 11 is displayed.

The robot controller 20 has a CPU 21, an SRAM 22, a storage device 23,
Conveyor control unit 24, conveyor 25, robot control unit 2
6, a bus 27. The CPU 21 reads a predetermined program from the storage device 23 and
The image processing apparatus 10 is developed in a work area 22a (not shown) in the storage 22, temporarily stores the developed program and processing results such as position coordinate data of the work 3, and executes various processes based on the program. , Robot control device 20
Centralized control of each part.

CPU (Central Processing Unit) 21
Creates the handling order data instructing the handling order of the work 3 from the position coordinate data of the work 3 input from the image acquisition control unit 13, and uses the handling order data as the handling data together with the position coordinate data of the work 3 to control the robot. At the same time as transmitting to the unit 25, the image data is temporarily stored in the SRAM 22, and is updated in real time each time an image is acquired by the visual recognition unit 12. The image acquisition control unit 13 and each unit of the robot control device 20 are connected to the bus 2
Various signals are transmitted / received to each other via 7, 28.

SRAM (Static Random Access Memor)
y) 22 forms a program code storage area for expanding various program codes when the CPU 21 executes various control programs, and also handles data of the work 3 and a processing result which are processed when the CPU 21 executes various processes. Etc. are stored in the work area 22a. The storage device 23 stores in advance the program and work data 23a such as the major axis and shape of the work 3 necessary for executing the program.

The conveyor controller 24 controls the conveyor motor 24 based on the position coordinate data of the work 3 input from the CPU 21 so as to set and maintain an optimum transfer speed at which the robot 26a can take out the work 3 without any loss time.
b is controlled. In addition, the conveyor 25 includes a first conveyor 25a and a second conveyor 25 that are different from each other in the transport direction.
c, and the reversing mechanism 25b, and the work 3 circulates at a constant speed on the conveyor 25 formed in a loop shape. The encoder 24a is attached to the conveyor 25, measures the moving distance of the first conveyor 25a in the x direction from the rotation amount of the conveyor motor 24b, and outputs the measurement result to the conveyor control unit 24.

The robot controller 26 controls the driving of the robot 26a based on the handling data of the work 3 stored in the SRAM 22. The hand 26b actually grips the work 3 in accordance with the drive control, and
Transfer to. At this time, the hand 26b determines whether or not the handling is performed reliably by the grip sensor, and the CPU 21 deletes the corresponding handling data from the work area 22a at the same time when the transfer of the work 3 is completed.

Next, the operation of the tracking system 1 having the above configuration will be described. First, the position coordinate detection process executed by the CPU 21 will be described with reference to FIG. 4 and based on the flowchart shown in FIG.

As shown in FIG. 3, the conveyor control unit 24
Drives the conveyor motor 24b to move the plurality of workpieces 3
Is transported in the x-axis direction on the conveyor 25 placed irregularly (step S1). Next, the CPU 21 sets “n = 1” in the work area 22a as the initial value of the counter “n”.
Is set (step S2). Next, the CCD camera 11
Acquires the image information of the imaging region 1 (see FIG. 4) as the first image information (step S3).

The visual recognition unit 12 analyzes the acquired image information and converts the position coordinate data of the work 3 in the image pickup area 1 into C.
The data is output to the PU 21 and temporarily stored in the SRAM 22 (step S4). At this time, the position coordinate data of the work (for example, the work 3a) located on the boundary of the imaging region 1 is not detected.

Next, based on the moving distance of the conveyor 25 calculated by the encoder 24a, the CPU 21
Assuming that the predetermined imaging pitch is “p”, the conveyor 25 sets “p =
It is determined whether or not “La” has been moved (step S5), and a standby state for signal input is entered. Here, “L” represents the width of the visible region in the x-axis direction as shown in FIG. “a” represents the width in the x-axis direction of the overlapping portion of each imaging region. In addition,
“A” is defined as “l ≦ a <L, where the major axis of the work 3 is“ l ”.
/ 2 ".

In step S5, when the conveyor 25 moves "p" (step S5; Yes), the CP
U21 outputs an imaging timing signal to the image acquisition control unit 13 (Step S6). At this time, the image acquisition control unit 13 is in a reception standby state for the signal, and determines whether or not the imaging timing signal has been received (step S
7).

When the image acquisition controller 13 receives the imaging timing signal (step S7; Yes), the CCD camera 11 acquires the image information of the imaging area 2 as the second image information (step S8). The visual recognition unit 12 analyzes the acquired image information, outputs the position coordinate data of the work 3 in the imaging area 2 to the CPU 21 and temporarily stores the data in the SRAM 22 (Step S9).

Next, the CPU 21 adds "1" to the counter "n" of the work area 22a of the SRAM 22,
“N = n + 1” is set (step S10). Then, the process returns to step S5 again, and the imaging region n + 1 and the imaging region n +
The processing of steps S5 to S9 is repeatedly performed on No. 2. And all the works 3 on the conveyor 25
When the coordinate conversion is completed, the above-described position coordinate detection processing ends.

Next, as a specific processing example based on the above processing, a position coordinate detecting method according to the present embodiment will be described with reference to FIG. FIG. 4 is a diagram showing an example of a position coordinate detecting step in one embodiment to which the present invention is applied.

In FIG. 4, by setting the width a of the overlapping portion between the imaging region 1 and the imaging region 2 to be equal to or longer than the major axis “l” of the work 3, the work 3 a positioned on the boundary line of the imaging region 1 becomes the imaging region 2. Includes the whole form. Therefore, the work 3a
Is not recognized as a work in the imaging region 1, but is recognized as a work in the imaging region 2.

By performing the above-described operations on the imaging region n and the imaging region n + 1, the imaging pitch p is always kept constant. There is no need to perform variable control of the imaging area. For this reason, the image processing time can be reduced, and the recognition omission of the work can be prevented. Along with this,
The transport speed of the conveyor 25 can be increased, and the processing capability of the entire tracking system 1 can be improved.

It should be noted that the present invention is not limited to the description in the above embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, in the present embodiment, the operator sets the major axis of the work 3 in advance and stores the setting information in the storage device 23 as the work data 23a.
May have a function of automatically recognizing the shape of the work 3 and calculating the major axis.

Although the conveyor 25 is transported at a constant speed, the conveyor 25 may be configured to have a function of changing or stopping according to the number of the workpieces 3 detected by the workpiece arrival detection sensor 14 and transported in a unit time. Good. further,
In the present embodiment, the image processing apparatus 10 is configured to recognize the image information of the work 3 two-dimensionally.
May be configured to three-dimensionally recognize the image information. Also,
The shape of the work 3 may not be the same.

[0037]

As described above, according to the present invention, since the front and rear imaging areas overlap each other with a width that can accommodate the entire shape of the work, the work is not missed, and the work on the boundary of the imaging area is recognized at the time of imaging. do not have to. In addition, since the imaging pitch before and after is always kept constant, it is not necessary to calculate the imaging pitch and perform variable control of the imaging area at the time of imaging. Therefore, the image processing time can be reduced, and the omission of recognition of the work can be reduced. Further, it is possible to increase the transport speed of the transport body, and it is possible to improve the tracking processing ability.

[Brief description of the drawings]

FIG. 1 is a schematic view of a tracking system according to the present embodiment, in which (a) is a plan view and (b) is a front view.

FIG. 2 is a block diagram illustrating a main configuration and a connection configuration of the tracking system.

FIG. 3 is a flowchart showing a position coordinate detection process executed by the CPU of FIG. 2;

FIG. 4 is a diagram illustrating an example of a position coordinate detecting step according to the present embodiment.

[Explanation of symbols]

 Reference Signs List 1 tracking system 10 image processing device 11 CCD camera 12 visual recognition unit 13 image acquisition control unit 14 component arrival detection sensor 15 display unit 20 robot control device 21 CPU 22 SRAM 23 storage device 24 conveyor control unit 25 conveyor 26 robot control unit 3 work

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masayuki Okuyama 3-3-5 Yamato, Suwa-shi, Nagano F-term in Seiko Epson Corporation (reference) 3F059 AA01 BB02 DB06 DB09 FB12 5B057 AA02 BA02 BA19 CE09 CH18 DA08 DA11 DC06 DC33

Claims (3)

[Claims] An imaging step of imaging a plurality of workpieces conveyed by a carrier in a predetermined imaging area; a coordinate acquisition step of acquiring position coordinates of each work from the imaging result; A tracking step of controlling the handling of a plurality of workpieces; and a tracking method of executing the tracking step, wherein the imaging area in the imaging step and the imaging area immediately after the imaging area overlap in the traveling direction with a constant width that accommodates the entire shape of the work. A tracking method, comprising: an output step of continuously outputting an imaging signal; and a visual recognition step of recognizing position coordinates of only a work including an entire shape in the imaging area. 2. An image processing apparatus which images a plurality of works conveyed by a conveyance body by an imaging unit and acquires position coordinates of each work from the imaging result, and handles the plurality of works based on the position coordinates. A tracking device comprising: a tracking device configured to control the imaging device, wherein the tracking device is configured such that an imaging region of the imaging unit and an imaging region immediately after the imaging device overlap in a traveling direction with a constant width that accommodates the entire shape of the work. Output means for continuously outputting an imaging signal to the image processing apparatus, wherein the image processing apparatus captures an image of a predetermined imaging area based on the imaging signal output from the output means, and forms an entire image in the imaging area. A visual recognition means for recognizing the position coordinates of only the work including the tracking system. 3. A tracking device for controlling handling of a plurality of works based on position coordinates of each work recognized from image information of the plurality of works obtained by an imaging means of an image processing device, wherein Output means for continuously outputting an imaging signal so that the imaging region and the imaging region immediately after the imaging region overlap in the traveling direction with a constant width in which the entire shape of the work is accommodated.