JP5648674B2 - Work position detection system - Google Patents

Description

  The present invention relates to a workpiece position detection system.

  Detecting the position of the workpiece is important in order to cause a device such as a robot and a crane to operate the workpiece accurately. In general, when a workpiece that is not positioned by a device such as a robot is supported, an imaging device for detecting the position of the workpiece is used. Also, there are many cases where a mechanism is added to illuminate the work so that the work can be easily recognized as an image and the position of the work can be detected stably. However, a workpiece that is a transparent body, such as an automobile window glass, has a problem in that it is difficult to pick up an image because the object to be detected is transparent, and light is transmitted even when illuminated, and detection is difficult.

Japanese Utility Model Publication No. 6-35905

  The present invention solves the above-described problems, and irradiates light so that the end face of a workpiece that is a transparent body emits light, thereby accurately detecting the position of the workpiece that is a transparent body. The purpose is to provide.

  The above object of the present invention is achieved by the following means.

The workpiece position detection system according to the present invention includes at least one light projecting unit that irradiates light so that the end surface of the workpiece that is a transparent body emits light, and a plurality of different light emission locations that are generated on the end surface of the workpiece by the light. It has an imaging unit for imaging, and a detector for detecting a position of the workpiece based on the imaging result by the imaging unit, the light projecting unit, morphism irradiation so as to cross the slit light to an end face of the workpiece and the imaging section, a plurality of bright points caused by multiple 箇 plants of the end face of the workpiece by the slit light simultaneously captured in the same field of view, the workpiece is one which is irradiated from one light projecting unit A curved end face capable of forming a plurality of intersections with respect to the slit light, and the detection unit is configured to detect the workpiece based on imaging results of a plurality of bright spots including at least the bright spots generated at the plurality of intersections. Check the position of Characterized in that it.

  According to the workpiece position detection system according to the present invention configured as described above, the light is emitted so that the end surface of the workpiece, which is a transparent body, emits light, and the light emitting portion generated on the end surface of the workpiece by the light is imaged. Since the position of the workpiece is detected based on the imaging result, the position of the workpiece that is a transparent body can be accurately detected.

It is a lineblock diagram of the window glass transfer system for vehicles in which the work position detection system of a 1st embodiment is used concretely. It is a block diagram of the mounting base shown in FIG. It is a system block diagram of the workpiece | work position detection system of FIG. FIG. 4a is a diagram showing a state in which a part of the illumination light emitted from the illumination light projecting unit is reflected inside the glass plate 2 and guided inside the glass plate 2, and FIG. It is a figure which shows the relationship between incident angle | corner (theta) 1 and a refraction angle, and reflection angle (theta) 2, ie, Snell's law (n1sin (theta) 1 = n2sin (theta) 2), when the refractive index of glass is n1 and n2, respectively. It is a schematic diagram which shows the state which the slit light irradiated from the light projection part for slit light and the end surface of a glass plate cross | intersect. The slit light projecting unit is also a schematic view showing that the slit light is irradiated obliquely with respect to the end surface of the glass plate. FIG. 7a is a diagram showing the relationship between the wavelength of illumination light having a specific wavelength band and the illuminance, and FIG. 7b is a diagram showing the relationship between the wavelength using a bandpass filter and the light shielding rate. FIG. 8A is a diagram illustrating an imaging result when no bandpass filter is provided by the illumination light imaging unit, and FIG. 8B is a diagram illustrating an imaging result when a bandpass filter is provided by the illumination light imaging unit. is there. FIG. 9A is a diagram illustrating an imaging result of the illumination light imaging unit, and FIG. 9B is a diagram illustrating an imaging result of the slit light imaging unit 22b. It is a flowchart which shows the processing content of the workpiece | work position detection system shown in FIG. It is a flowchart which shows the processing content of the workpiece | work position detection system shown in FIG. It is a system configuration figure showing a 2nd embodiment. It is a figure which shows the imaging result of the imaging part for illumination light shown in FIG. It is a block diagram of the window glass transfer system for vehicles in which the workpiece | work position detection system of 2nd Embodiment is used concretely. It is a system configuration figure showing a 3rd embodiment. It is a schematic diagram which shows the state which the slit light irradiated from the light projection part for slit light and the end surface of a glass plate cross | intersect. FIG. 17A is a diagram illustrating a state in which radiation is applied to the glass plate 2 from the ultrasonic measurement unit 24, and FIG. 17B is a diagram illustrating a state in which radiation is applied to the glass plate 2 from the ultrasonic measurement unit 24. FIG. 18a is a conceptual diagram showing the positional relationship between the pallet and the glass for detecting the glass position in the pallet, and FIG. 18b shows the positional relationship between the pallet and the glass for detecting the glass position in the pallet. It is a conceptual diagram represented. It is a flowchart which shows the specific procedure shown in FIG. It is a system configuration figure showing a 4th embodiment. It is a system configuration figure showing a 5th embodiment. It is a flowchart which shows the processing content of the workpiece | work position detection system shown in FIG. It is a flowchart which shows the processing content of the workpiece | work position detection system following FIG. 22a. It is a flowchart which shows the processing content of the modification of the workpiece | work position detection system shown in FIG.

  Hereinafter, a workpiece position detection system according to a preferred embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
In the first embodiment of the present invention, a case where a workpiece position detection system is applied to a vehicle window glass plate transfer system will be described as an example. That is, in this embodiment, the window glass plate for vehicles is employ | adopted as a workpiece | work (henceforth a "transparent body workpiece | work") which is a transparent body.

  FIG. 1 shows an example of a vehicle window glass transfer system (hereinafter referred to as a “transfer system”) to which the workpiece position detection system of the present embodiment is applied.

  As shown in FIG. 1, a transfer system (work transfer system) 1 is a robot (conveying unit) 10a for supporting a vehicle window glass plate (hereinafter referred to as a “glass plate”) which is a transparent workpiece. , 10b and a workpiece position detection system 20 for detecting the position of the glass plate in a state where the robot 10a supports the glass plate.

  Here, the glass plates 2a to 2h (hereinafter collectively referred to as “glass plate 2”) are supplied in a state of being accommodated in first pallets 3a to 3h (hereinafter collectively referred to as “first pallet 3”). . Preferably, the first pallet (first storage unit) 3 is a transport pallet used for transporting the glass plate 2. The plurality of glass plates 2 are housed in the first pallet 3 in a stacked state with a predetermined interval therebetween. In each of the first pallets 3a to 3h, a glass plate 2 corresponding to a different vehicle type / specification is stored for each pallet, and the same type of glass plate is stored in one pallet. The glass plates 2a to 2d accommodated in the first pallets 3a to 3d are transferred to the second pallets 4a to 4c (hereinafter collectively referred to as “second pallet 4”) by the robot 10a according to the production order of the vehicle. To the next vehicle assembly process. Moreover, the glass plates 2e-2h accommodated in the first pallets 3e-3h are transferred to the temporary storage place 5 by the robot 10b. Next, the glass plates 2e to 2h transferred to the temporary storage place 5 are supported by the robot 10a, transferred to the second pallet (second storage unit) 4 in the vehicle production order, and transferred to the next step. . In addition, although the position and attitude | position are fixed to some extent by the support by the 1st pallet 3, the several glass plate 2 varies in position and attitude | position within the tolerance | permissible_range. In addition, there are variations in dimensions of the first pallet 3 itself, variations in position when the first pallet 3 is installed, and the like. Therefore, every time the robot 10a supports the glass plate 2, the position and posture of the glass plate 2 may be different. Therefore, when the robot 10a transfers the glass plate 2 to the second pallet 4, the robot 10a removes the glass plate 2. In the supported state, it is necessary to detect the position and posture of the glass plate 2 using the workpiece position detection system 20 to correct the movement of the robot 10a.

  For example, as shown in FIG. 1, the robots 10a and 10b for transferring the glass plate 2 have a temporary storage place 5 placed on the work floor so that the robot 10a can support the glass plates 2a to 2d. Are arranged so as to support the glass plates 2e to 2h. The robots 10a and 10b are configured to operate in response to a control signal from a controller 11 (not shown). Specifically, the controller 11 transmits a control signal to the robot 10a and / or the robot 10b depending on which one of the first pallets 3 contains the glass plate to be transferred, and the robot 10a and / or the robot 10b. 10b supports a glass plate from the approach position defined for each of the first pallets 3a to 3h based on this control signal. Here, when supporting the glass plate, the robots 10a and 10b may hold or adsorb the glass plate.

  Next, the workpiece position detection system 20 that detects the position of the glass plate 2 will be described. As shown in FIG. 1, the workpiece position detection system 20 is configured to be able to detect the position of the glass plate 2 supported by the robot 10a.

  The workpiece position detection system 20 includes a plurality of light projecting units 21a, 21b, and 21c, imaging units 22a and 22b, and a controller 11 that performs various calculations and controls related to position detection. Here, in the present embodiment, the controller 11 is a robot controller for controlling the robots 10 a and 10 b as described above, and plays a part of the work position detection system 20. Note that the plurality of light projecting units 21b and 21c and the image capturing units 22a and 22b are provided, for example, using a mount 6 provided in the vicinity of the second pallet 4 as shown in FIG. Moreover, although the light projection part 21a is provided, for example in the robot hand which supports the glass of the robot 10a, if the conditions mentioned later are satisfy | filled, you may provide in other locations, such as the mounting base 6. FIG.

  FIG. 3 is a block diagram showing the workpiece position detection system 20 shown in FIG. Hereinafter, based on FIG. 3, the light projecting units 21 a, 21 b, 21 c, the imaging units 22 a, 22 b, and the controller 11 constituting the work position detection system 20 will be described in order.

<Light projecting part>
The light projecting unit 21a is a light emitter that irradiates illumination light obliquely onto the surface of the glass plate 2 that is a transparent workpiece. Here, the illumination light is usually light for illuminating the part to be measured in order to capture an image, and any light can be used as long as the image can be captured. Here, with reference to FIG. 4, a relationship between a light projecting unit (hereinafter referred to as “illuminating light projecting unit”) 21 a that irradiates illumination light and the surface of the glass plate 2 will be described. FIG. 4A is a diagram illustrating a state in which a part of the illumination light 100 a irradiated from the illumination light projecting unit 21 a is reflected inside the glass plate 2 and guided inside the glass plate 2. FIG. 4B is a diagram showing the relationship between the incident angle θ1, the refraction angle, and the reflection angle θ2, that is, Snell's law (n1sin θ1 = n2sin θ2) when the refractive indexes of air and glass are n1 and n2, respectively. . Here, for example, the refractive indexes of air and glass are n1 = 1 and n2 = 1.5, respectively.

As shown in FIG. 4A, the illumination light projecting unit 21 a irradiates the surface of the glass plate 2 with the illumination light 100 a obliquely, and at least a part of the illumination light 100 a guided inside the glass plate 2. Is radiated from the end surface of the glass plate 2 to concentrate light on the end surface of the glass plate 2 to emit light. Preferably, irradiating the illumination light at an incident angle θ1 as the reflection angle θ2 on the surface of the glass plate 2 is larger than the total reflection critical angle theta _0. Here, the total reflection critical angle θ ₀ means that when light is irradiated from a material having a high refractive index to a material having a low refractive index, that is, when light is irradiated from the inside of the glass to the outside (air), the inside of the glass plate 2 This is the minimum angle when total reflection occurs. θ ₀ can be obtained by sinθ ₀ = n1 / n2. In addition, when the glass plate 2 has a curved shape as in the present embodiment, the critical angle may change every time it is reflected, but at least a part of the illumination light is totally reflected inside the glass plate 2, If the end surface of the glass plate 2 emits light strongly, the object of the present invention can be achieved.

  The light projecting portions 21b and 21c are light emitters that irradiate slit light so as to intersect the end surface 201 of the glass plate 2 that is a transparent workpiece. Therefore, unlike the light projection part in a general position detection system, slit light is irradiated from the end surface 201 side of the glass plate 2 which is a transparent workpiece. Here, the slit light is light having an irradiation region extending linearly. For example, the light projecting units 21 b and 21 c are light projecting units that irradiate slit-shaped laser light (hereinafter referred to as “slit light projecting unit”). The slit light projecting portions 21b and 21c can be configured by, for example, a semiconductor laser element and other optical systems, and the configuration itself is the same as that of a general slit light emitter, and thus detailed description thereof is omitted. To do.

  Next, with reference to FIG. 5, the relationship between the slit light irradiated from the slit light projecting portions 21b and 21c and the end surface 201 of the glass plate 2 will be described. FIG. 5 is a schematic diagram illustrating a state in which the slit light irradiated from the slit light projecting portions 21 b and 21 c intersects the end surface of the glass plate 2.

  As shown in FIG. 5, the slit light projecting portions 21b and 21c irradiate the slit light 100b and 100c. As a result, bright spots P1 and P2 are generated on the end face of the glass plate 2. Here, when the slit light projecting portions 21b and 21c irradiate the slit light 100b and 100c perpendicularly to the glass plate 2 from above the glass plate 2, bright spots may be generated on portions other than the end surface 201 of the glass plate 2. There is a possibility that it becomes an obstacle when position detection described later is performed. That is, when the slit light projecting portions 21b and 21c are vertically irradiated on the glass plate 2, bright spots may be generated not only on the upper end surface of the glass plate 2, but also on the lower end surface. The resulting bright spots overlap. Therefore, as a result of imaging with the imaging unit 22b disposed above the glass plate 2, there is a possibility that the bright spot generated on the upper end face cannot be determined. Therefore, as shown in FIG. 6, it is desirable that the slit light projecting portions 21 b and 21 c irradiate the slit light 100 b and 100 c obliquely with respect to the end surface 201 of the glass plate 2. As a result, in the imaging result of the imaging unit, the innermost bright spot can be regarded as the bright spots P1 and P2 generated on the end face of the glass plate 2, and erroneous recognition can be prevented when performing position detection.

  The illumination light projecting unit 21a irradiates illumination light 100a having a specific wavelength band as shown in FIG. 7A, so that a band pass filter 220 is provided in the imaging unit 22a described below. As shown in FIG. 7B, disturbance light other than the light emitted from the end surface 201 of the glass plate 2 can be cut to facilitate the recognition of the glass plate 2. For example, when the imaging unit 22a images a portion where the slit light 100b and the illumination light 100a overlap, the imaging result when the bandpass filter 220 is not provided is as shown in FIG. 8A, and the bandpass filter 220 is provided. The imaging result is as shown in FIG.

<Imaging unit>
Next, returning to FIG. 3, the imaging units 22a and 22b will be described. The imaging unit 22a is an imaging unit (hereinafter referred to as an “illumination light imaging unit”) that captures a concentrated point (radiation point) Q1 of light generated on the end surface 201 of the glass plate 2 by the illumination light 100a, that is, a location that emits intense light. ). The imaging unit 22b is an imaging unit that captures a plurality of bright spots P1 and P2 generated at a plurality of locations on the end surface 201 of the glass plate 2 by the slit lights 100b and 100c (hereinafter referred to as “slit light imaging unit”). . Specifically, the imaging unit for illumination light 22a and the imaging unit for slit light 22b can be configured by an imaging element such as a CCD element and other optical systems, and the configuration itself is the same as a general imaging unit. Because there is, detailed explanation is omitted. The illumination light imaging unit 22a is preferably provided with a band-pass filter 220 as described in the above light projecting unit. Further, as shown in FIG. 4A, it is desirable to arrange the light projecting unit 21a and the imaging unit 22a so that the illumination light 100a does not directly hit the illumination light imaging unit 22a.

<Controller>
As described above, the controller 11 is a robot controller for controlling the robots 10a and 10b, and plays a part of the work position detection system 20.

  The controller 11 includes components such as a central processing unit (CPU) composed of a microprocessor, a ROM memory, a RAM memory, a nonvolatile memory, a teaching operation panel, and a communication interface coupled to the CPU. The ROM memory stores a program such as a system program for controlling the robot. The RAM memory is used for temporary storage of data for processing executed by the CPU. The nonvolatile memory stores, for example, operation program data, robot teaching data, and various setting values necessary for the operation of the robot and the like. The teaching operation panel is used, for example, when inputting teaching data of the robots 10a and 10b. The communication interface communicates between the robots 10a and 10b, the illumination light projector 21a, the slit light projectors 21b and 21c, the illumination light imaging unit 22a, and the slit light projector 22b and the controller 11. Connect as possible.

  The controller 11 transmits a signal for instructing irradiation of illumination light (hereinafter, referred to as “illumination light irradiation signal”) to the illumination light projecting unit 21a, and a signal for instructing irradiation of slit light (hereinafter, referred to as “illumination light irradiation signal”). , “Slit light irradiation signal”) is transmitted to the slit light projecting sections 21b, 21c, and a signal for instructing imaging of illumination light (hereinafter referred to as “illumination light imaging signal”) is used for illumination light. A signal for instructing imaging of slit light (hereinafter referred to as “imaging signal for slit light”) is transmitted to the imaging unit 22a, and transmitted to the imaging units 22b and 22c for slit light.

  The controller 11 functions as a detection unit as described below.

  The detection unit receives a data signal of the imaging result from the imaging unit for illumination light 22a and the imaging unit for slit light 22b, and detects the position of the glass plate 2 that is a transparent workpiece based on the data signal of the imaging result. To do. Below, the method to detect the position of the glass plate 2 which is a transparent body workpiece | work processed by the detection part of the controller 11 is demonstrated in detail, referring FIG. FIG. 9A is a diagram illustrating an imaging result of the illumination light imaging unit 22a, and FIG. 9B is a diagram illustrating an imaging result of the slit light imaging unit 22b.

  First, the reference shape is set in the controller 11. The reference shape is, for example, a position where the robot 10a serves as a reference for supporting the glass plate 2 (hereinafter referred to as a “reference position”), and when the robot 10a is moved to the imaging space 300 while being supported at the reference position, It is the shape which the imaging part 22a for light and the imaging part 22b for slit light image. That is, the reference shape is set as shown in FIGS. 9A and 9B, for example. The reference location is teaching data set in advance in the controller 11 and is a location where the robot 10a supports the glass plate 2 when the robot 10a can accurately store the glass plate 2 in the second pallet 4. Therefore, when the robot 10a supports the glass plate 2 other than the reference location, the shape captured by the illumination light imaging unit 22a and the slit light imaging unit 22b is different from the reference shape. It is possible to calculate which position of the glass plate 2 is supported. After the calculation, the teaching data of the robot 10 a can be corrected and the glass plate 2 can be accurately stored in the second pallet 4. The imaging space 300 is a predetermined space in which the illumination light imaging unit 22a and the slit light imaging unit 22b can capture the glass plate 2 as shown in FIG. Below, the method to detect the position of the glass plate 2 which is a transparent body workpiece | work processed by the detection part of the controller 11 is demonstrated in detail.

  First, the robot 10a supporting the glass plate 2 moves the robot hand of the robot 10a to the imaging space 300 in front of the mount 6 so that the workpiece position can be detected. The imaging space 300 is expressed in a coordinate system with x, y, and z axes. In the present embodiment, the illumination light imaging unit 22a is disposed so as to capture an xz plane, and the slit light imaging unit 22b is disposed so as to capture an xy plane. Therefore, the reference shape of the controller 11 is that the imaging unit for illumination light 22a images the xz plane, and the imaging unit for slit light 22b images the yz plane. Here, in this embodiment, the glass plate 2 rotates θz around the z axis, α translates in the x axis direction, β translates in the y axis direction, and γ translates in the z axis direction. As a result, the various parameters (θz, α, β, γ) can be obtained from the detection result of the detection unit. Therefore, as shown in FIG. 9, it is possible to obtain the parameters (α, γ) in the illumination light imaging unit 22a and the parameters (θz, β) in the slit light imaging unit 22b. That is, by comparing the shape captured by the illumination light imaging unit 22a and the slit light imaging unit 22b with the reference shape, various parameters that are movement amounts from the reference location where the robot 10a supports the glass plate 2 are obtained. The controller 11 can calculate (θz, α, β, γ).

  The workpiece position detection system 20 of the present embodiment configured as described above is executed as follows.

  FIG. 10 is a flowchart showing the processing contents of the workpiece position detection system 20 of the present embodiment.

  First, the controller 11 instructs to take out the glass plate from any one of the first pallets 3a to 3h (step S1). Next, the controller 11 determines whether the accommodation pallet of the glass plate instructed to be taken out is the first pallets 3a to 3d processed by the robot 10a or the first pallets 3e to 3h processed by the robot 10b. (Step S2).

  The controller 11 determines whether or not the remaining number of glasses in the first pallets 3a to 3h corresponding to the pallet for taking out the glass plate is zero (steps S3a and 3b). Whether or not the remaining glass number in the pallet is zero can be determined by using, for example, a counter provided on the pallet and the controller 11 receiving the output of the counter.

  If the remaining number of glass plates in the pallet for taking out the glass plates is zero, the controller 11 displays that the first pallet is empty (pallet empty output) (steps S4a, 4b).

  When the controller 11 instructs to take out the glass plate 2 from the first pallets 3e to 3h, the controller 11 first instructs the robot 10b to support and take out the glass (step S5). And the controller 11 instruct | indicates to put the glass plate 2 supported by the robot 10b on the temporary placement stand 5 (step S6).

  After the robot 10b places the glass plate 2 on the temporary table 5, the controller 11 transmits a signal indicating completion of removal to the robot 10b, and the robot 10b returns to the original position (step S7). The controller 11 determines whether or not there is a space for storing the glass plate 2 of the second pallet 4 (step S8). Whether or not there is an empty space for storing the glass plate 2 of the second pallet 4 can be determined by, for example, using a counter provided on the pallet and the controller 11 receiving the output of the counter. If there is no space for storing the glass plate 2 of the second pallet 4, the second pallet 4 that should store the glass plate 2 is replaced with an empty pallet, that is, the empty second pallet is in the storage location. It will be in a standby state until it moves.

  Next, the controller 11 instructs the robot 10a to take out the glass plates 2 from the respective pallets if they are the first pallets 3a to 3d and from the temporary placing table 5 if they are the first pallets 3e to 3h. (Step S9).

  The controller 11 moves the robot hand to the imaging location for detecting the workpiece position while the robot 10a supports the glass plate 2 (step S10). Then, the controller 11 detects the work position (step S11). The workpiece position detection process will be described with reference to the flowchart of FIG.

  Then, after detecting the workpiece position, the controller 11 aligns the robot 10a with the second pallet 4 based on the detection result (step S12).

  Hereinafter, the workpiece position detection will be described in detail with reference to the flowchart of FIG.

  First, the controller 11 instructs the slit light projecting sections 21b and 21c to irradiate slit light (step S21).

  Next, the controller 11 instructs the imaging unit 22b for slit light to image the bright spots P1 and P2 on the end surface 201 of the glass plate 2 irradiated by the slit light from the light projecting units 21b and 21c for slit light (step) S22).

  The controller 11 executes capturing of the imaging results of the bright spots P1 and P2 imaged by the slit light imaging unit 22b (step S23).

  The controller 11 calculates the parameters (β, θz) by comparing the preset teaching data (teaching shape) with the shapes of the bright spots P1 and P2 of the imaging result as described above (step S24).

  After calculating the parameters (β, θz), the controller 11 instructs the slit light projectors 21b and 21c to turn off the irradiation of the slit light (step S25).

  The controller 11 instructs the illumination light projecting unit 21a to irradiate illumination light (step S26).

  Next, the controller 11 instructs the illuminating light imaging unit 22a to image a light emitting spot (radiating spot) Q1 generated on the end surface of the glass plate 2 irradiated by the illuminating light from the illuminating light projector 21a ( Step S27).

  The controller 11 captures the imaging result of the light emitting spot Q1 captured by the illumination light imaging unit 22a (step S28).

  The controller 11 calculates the parameters (α, γ) by comparing the preset teaching data (teaching shape) with the shape of the light emission location (radiation location) Q1 of the imaging result as described above (step S29).

  After calculating the parameters (α, γ), the controller 11 instructs the slit light projectors 21b and 21c to turn off the irradiation of the slit light (step S30).

  Note that steps S21 to S25, which are parameter (β, θz) position detection processing, and steps S26 to S30, which are parameter (α, γ) position detection processing, may be reversed in order. It is also possible to execute processing simultaneously.

  As described above, the glass position can be calculated from the results of various parameters (θz, α, β, γ) (step S31).

  In the above processing, the processing after step S21 corresponds to the processing of the slit light projecting unit. The processing after step S26 corresponds to the processing of the illumination light projecting unit.

  Moreover, the process of step S22-step S23 respond | corresponds to the process of the imaging part for slit light. The processing of step S27 to step S28 corresponds to the processing of the illumination light imaging unit.

  Further, the processing in step S24 and step S29 corresponds to the processing of the detection unit.

  As described above, according to the workpiece position detection system 20 of the present embodiment, the following effects (A) to (K) are achieved.

  (A) At least one light projecting unit that irradiates light so that the end surface of the glass plate that is a transparent body emits light, an imaging unit that captures a light emission location generated on the end surface of the glass plate by light, and imaging by the imaging unit Since it has a detection part which detects the position of a glass plate based on a result, even if the object to image is a transparent body by irradiating light so that the end face of a glass plate may emit light, it is glass which is a transparent body The position of the plate can be accurately detected.

  (B) Since a plurality of light projecting portions are provided, a plurality of light emitting portions are generated on the end face of the workpiece for use in workpiece position detection, and the position of the glass plate that is a transparent body based on the plurality of light emitting portions. By detecting this, the position of the glass plate can be detected in detail.

  (C) Since the end face of the glass plate can be made to emit light strongly by irradiating the illumination light and concentrating at least part of the illumination light guided inside the glass plate on the end face of the glass plate, Imaging becomes easy.

  (D) By irradiating the surface of the glass plate with irradiation light from an oblique direction and totally reflecting at least part of the irradiation light inside the glass plate, the illumination light does not completely pass through the glass plate, and the end surface of the glass plate is Strong light can be emitted.

  (E) The light projecting unit irradiates the surface of the glass plate with illumination light at an incident angle greater than the total reflection critical angle, so that the illumination light is totally reflected inside the glass plate and strongly emits light at the end. it can.

  (F) The light projecting unit irradiates illumination light of a specific wavelength band, and the imaging unit includes a filter that selectively transmits illumination light of the specific wavelength band, so that the illumination light is irradiated on the end surface of the glass plate. Light other than light emission is cut, and stable imaging by the imaging unit can be performed.

  (G) The glass plate is supported by the robot, and the detection unit detects the position of the glass plate based on the imaging result captured by the imaging unit while being supported by the robot, so that the robot detects the glass plate 2. Can be accurately stored in the second pallet according to the detection result of the detection unit, even if it is not instructed completely and accurately.

  (H) The light projecting unit irradiates slit light so as to intersect the end surface of the glass plate, and the imaging unit images a plurality of bright spots generated at a plurality of locations on the end surface of the glass plate by the slit light, Even if the object to be imaged is a transparent body, the position of the glass plate that is the transparent body can be accurately detected.

  (I) A light projection part irradiates slit light with respect to the end surface of a glass plate diagonally, and when an imaging part images the glass plate 2, only the bright spot used for a position detection is detected stably. be able to.

  (J) A plurality of light projecting sections are provided, and the detection section is made of glass based on imaging results of a plurality of bright spots generated at a plurality of locations on the end face of the glass plate by the respective slit lights irradiated from the plurality of light projecting sections. By detecting the position of the plate, the position of the glass plate can be detected in detail.

  (K) The light projecting unit illuminates the surface of the glass plate with illumination light, and emits at least part of the illumination light guided inside the glass plate from the end surface of the glass plate, and the glass plate A slit light projecting unit that irradiates slit light so as to intersect the end surface of the light source, and the imaging unit includes an illumination light imaging unit that images a radiation location generated on the end surface of the glass plate by the illumination light, and the slit light. A slit light imaging unit that images a bright spot generated on the end surface of the glass plate, and the detection unit detects the position of the glass plate based on the imaging results of the illumination light imaging unit and the slit light imaging unit. Thus, the position of the glass plate can be detected in detail.

<Second Embodiment>
Next, a second embodiment of the present invention will be described in detail.

  As shown in FIG. 12, the workpiece position detection system 20 of the second embodiment replaces the slit light projectors 21b and 21c and the slit light imaging unit 22b, which are constituent devices of the first embodiment. The position of the glass plate, which is a transparent body, can be detected based on the imaging results of only the illumination light imaging unit from a plurality of directions using the illumination light projecting unit 21d and the illumination light imaging unit 22c. System. Further, in the workpiece position detection system of the second embodiment, the glass plate 2 is rotated by θz around the z axis, is α translated in the x axis direction, and is moved in the y axis direction, as in the first embodiment. The various parameters (θz, α, β, γ) can be obtained from the detection result of the detection unit, assuming that β is translated and γ is translated in the z-axis direction.

  The workpiece position detection system 20 according to the second embodiment includes a plurality of illumination light projection units 21a and 21d and illumination light imaging units 22a and 22d, and a controller 11 that performs various calculations and controls related to position detection. Including. Moreover, the imaging parts 22a and 22d for illumination light are provided, for example using the attachment stand 6 as shown in FIG. In addition, the illumination light projector 21d is provided, for example, in a robot hand that supports the glass plate of the robot 10a, similarly to the illumination light projector 21a. Hereinafter, the description of the same components as those of the second embodiment and the first embodiment will be omitted.

  The illumination light projecting unit 21d is a light emitter that irradiates illumination light obliquely onto the surface of the glass plate 2 that is a transparent workpiece, similarly to the illumination light projecting unit 21a. The illumination light projector 21 a is for imaging the xz plane of the imaging space 300, and the illumination light projector 21 d is for imaging the xy plane of the imaging space 300.

  The controller 11 transmits the illumination light irradiation signal to the illumination light projection units 21a and 21d, and transmits the illumination light imaging signal to the illumination light imaging units 22a and 22c. Below, the method to detect the position of the glass plate 2 which is the transparent body workpiece | work processed by the detection part of the controller 11 is demonstrated in detail, referring FIG. FIG. 13 is a diagram illustrating the imaging result of the illumination light imaging unit 22c. The illumination light imaging unit 22a is the same as in the first embodiment, and a description thereof will be omitted.

  First, the reference shape is set in the controller 11 as in the first embodiment. The reference shape is set, for example, as shown in FIG. The workpiece position can be detected and the parameters (β, θz) can be calculated by comparing the preset reference shape and the shape imaged by the illumination light imaging unit 22c. Further, similarly to the first embodiment, since the parameters (α, γ) can be calculated by the illumination light imaging unit 22a, various types of movement amounts from the reference position where the robot 10a supports the glass plate 2 are used. The parameters (θz, α, β, γ) can be obtained by the controller 11.

  Here, the illumination light projection unit 21a is a projection unit that emits illumination light in a specific wavelength band (hereinafter referred to as “first wavelength band”) (hereinafter, “first wavelength band projection unit”). The illumination light projecting unit 21d emits illumination light in a specific wavelength band (hereinafter referred to as “second wavelength band”) different from the first wavelength band (hereinafter referred to as “first”). It is desirable to use a “two-wavelength band projecting unit”. Disturbance light other than light emitted from the end surface 201 of the glass plate 2 by providing bandpass filters 220 and 221 that selectively transmit the first wavelength band and the second wavelength band respectively in the imaging units 22a and 22c for illumination light. The glass plate 2 can be easily recognized without being interfered with each other's illumination light.

  The illumination light projectors 21a and 21d and the illumination light imaging so that the illumination light 100a does not directly strike the illumination light imaging unit 22a and the illumination light 100d does not directly strike the illumination light imaging unit 22c. It is desirable to arrange the portions 22a and 22c.

  As described above, according to the work position detection system 20 of the second embodiment, in addition to the effects (A) to (G) of the first embodiment, the following effects (L) and (M) are achieved. .

  (L) When the slit light projecting unit is used, bright spots can be generated on portions other than the end face of the glass plate, and the process of detecting the position of the glass plate based on the imaging result becomes complicated. However, if the workpiece position detection process is performed only with the illumination light projecting unit, only the end face of the glass plate emits light, and disturbance light can be cut by a bandpass filter, enabling stable glass plate position detection. It is.

  (M) The light projecting unit includes a first wavelength band projecting unit that irradiates illumination light in the first wavelength band and a second wavelength band projecting unit that irradiates illumination light in the second wavelength band, The imaging unit includes a first wavelength band imaging unit that includes a filter that selectively transmits illumination light in the first wavelength band, and a second wavelength band that includes a filter that selectively transmits illumination light in the second wavelength band. By including the imaging unit, disturbance light other than light emitted from the end surface 201 of the glass plate 2 can be cut, and the glass plate 2 can be easily recognized without being interfered with each other's illumination light. .

<Third Embodiment>
Next, a third embodiment of the present invention will be described in detail.

  As illustrated in FIG. 14, the workpiece position detection system 20 according to the third embodiment is configured to be able to detect the position of the glass plate 2 even when the glass plate 2 remains in the first pallet 3. Yes. That is, unlike the first embodiment and the second embodiment, the robot does not detect the workpiece position after supporting the glass plate 2, but detects the workpiece position before supporting the glass plate so that the robot can detect the glass plate. 2 is supported at the reference point.

  As shown in FIG. 15, the workpiece position detection system 20 moves a plurality of light projecting units 21 e and 21 f and an image capturing unit 22 d provided above the first pallet 3 and at least a part of the light projecting units 21 e. The moving part 23 to perform, the ultrasonic measuring device 24, and the controller 11 which performs various calculations and control regarding position detection are included. Here, in the third embodiment, the controller 11 is a robot controller for controlling the robots 10a and 10b, as in the first embodiment, and plays a part of the work position detection system 20. ing. In FIG. 14, only the light projecting units 21e and 21f and the imaging unit 22e above the first pallet 3A are shown, but the same light projecting unit is also disposed above the other first pallets (3b to 3h). And an imaging part may be provided.

<Light projecting part>
The light projecting portions 21e and 21f are light emitters that irradiate slit light so as to intersect the end surface 201 of the glass plate 2 that is a transparent workpiece. The light projecting unit itself is the same as the light projecting units 21b and 21c used in the first embodiment.

  The light projecting units 21e and 21f include a first light projecting unit 21e moved by the moving unit 23 and a fixed second light projecting unit 21f. Here, with reference to FIG. 16, the relationship between the slit light irradiated from the 1st light projection part 21e and the 2nd light projection part 21f and the end surface 201 of the glass plate 2 is demonstrated. FIG. 16 is a schematic diagram illustrating a state in which the slit light irradiated from the first light projecting unit 21 e and the second light projecting unit 21 f intersects the end surface of the glass plate 2.

  As shown in FIG. 16, the transparent workpiece in the present embodiment, that is, the glass plate 2 is irradiated from the first light projecting unit 21 e that is one of the plurality of light projecting units 21 e and 21 f. A curved end face 201 capable of forming a plurality of intersections with respect to the single slit light 100e is provided. Specifically, the 1st light projection part 21e irradiates one slit light 100e which cross | intersects the end surface 201 of the glass plate 2 at two intersections. As a result, bright points P3 and P4 are generated at the two intersections. In the present embodiment, the first light projecting unit 21e moves the moving unit 23 so that one slit light 100e intersects the end surface 201 of the glass plate 2 at a plurality of locations.

  On the other hand, the second light projecting portion 21f is another slit that intersects the end surface 201 of the glass plate 2 at a location other than the two intersections (bright spots P3 and P4) by the slit light 100e from the first light projecting portion 21e. Irradiates light 100f. As a result, a bright spot P5 is generated at one intersection. Desirably, the 2nd light projection part 21f irradiates the slit light 100f which cross | intersects the end surface 201 of the glass plate 2 in one place pinched | interposed by said two intersection.

<Imaging unit>
Next, returning to FIG. 15, the imaging unit 22d will be described. The imaging unit 22d images a plurality of bright spots P3, P4, and P5 generated at a plurality of locations on the end surface 201 of the glass plate 2 by the slit light 100e and the slit light 100f. The imaging unit itself is the same as the imaging unit used in the first embodiment.

<Moving part>
As described above, the moving unit 23 moves at least one light projecting unit, and specifically moves the first light projecting unit 21e. That is, the moving unit 23 changes at least one of the position or orientation of the first light projecting unit 21e. Therefore, the irradiated location of the glass plate 2 which is a transparent workpiece can be changed by the slit light 100e from the first light projecting unit 21e. For example, the moving unit 23 is a linear actuator, and the configuration itself is the same as that of a general moving unit, and thus detailed description thereof is omitted.

  Unlike the present embodiment, the irradiation angle of the slit light 100e may be changed by the structure of the first light projecting unit 21e itself without using the moving unit 23.

<Ultrasonic measurement unit>
An ultrasonic measurement part measures the distance from an ultrasonic measurement part to a glass plate using an ultrasonic wave. Specifically, the distance can be calculated based on the time until the ultrasonic wave is transmitted to the surface 202 of the glass plate 2 and the reflected wave is received. For example, as shown in FIG. 17A, the ultrasonic measurement unit is attached to the robot hand that is a portion that supports the glass plate 2 of the robots 10 a and 10 b, thereby allowing the distance between the robot hand and the ultrasonic measurement unit 24. Can be measured.

  In addition, as shown in FIG. 17B, three ultrasonic measurement units 24 can be provided in the robot hand. In this case, the distance to the glass, the distance in the pallet is calculated from the distance calculation result of each measurement unit. It is also possible to detect the angle of the glass plate with respect to the pallet and the position of the glass plate in the longitudinal direction.

<Controller>
Similarly to the first embodiment, the controller 11 is a robot controller for controlling the robot 20 and plays a part of the work position detection system 10.

  The controller 11 transmits a signal for instructing irradiation of slit light (hereinafter referred to as “irradiation signal”) to the first light projecting unit 21e and the second light projecting unit 21f, and a signal for instructing imaging ( Hereinafter, it is referred to as an “imaging signal”) to the imaging unit 22d. The communication interface of the controller 11 connects the robots 10a and 10b, the first light projecting unit 21e, the second light projecting unit 21f, the image capturing unit 22d, and the controller 11 so that they can communicate with each other.

  The controller 11 functions as a determination unit, a correction unit, a comparison unit, and a detection unit as described below.

  The determination unit determines whether or not the slit light 100e intersects the end face of the glass plate 2 at two intersections. That is, the determination unit determines whether the slit light 100e intersects the end surface 201 of the glass plate 2 at two intersections based on the data signal of the imaging result from the imaging unit 22d obtained by the detection unit as shown below. The first light projecting unit 21e is moved by the moving unit 23 so that the slit light 100e intersects the end surface 201 of the glass plate 2 at two intersections according to the determination result.

  The correction unit corrects teaching data of the robots 10a and 10b for supporting the glass plate 2 which is a transparent workpiece. That is, the correction unit corrects the teaching data of the robots 10a and 10b based on the positional relationship between the first pallet 3 and the glass plate 2 obtained by the detection unit as shown below, and sends control signals to the robots 10a and 10b. Send.

  The comparison unit compares the distance measurement result of the ultrasonic measurement unit 24 with the result of position detection of the glass plate 2 in the detection unit described below. Specifically, in the present embodiment, the robots 10a and 10b support the glass plate 2 based on the workpiece position detection result, but the comparison unit confirms whether there is an error in the detection result.

  The detection unit receives the data signal of the imaging result from the imaging unit 22d, and detects the position of the glass plate 2 that is the transparent workpiece based on the data signal of the imaging result. Below, the method to detect the position of the glass plate 2 which is a transparent body workpiece | work processed by the detection part of the controller 11 is demonstrated in detail, referring a figure.

  The detection unit uses the coordinate system in the first pallet 3 as a reference coordinate system, and obtains a relative positional relationship between the reference coordinate system and the coordinate system of the glass plate 2 that is a transparent workpiece by a plurality of bright spots. is there. The reference coordinate system is, for example, a coordinate system in which the x, y, and z axes are determined in the first pallet 3 as shown in FIG. The y-axis of the reference coordinate system is the stacking direction when the glass plates 2 are arranged in a stacked state in the first pallet 3, and the z-axis of the reference coordinate system is relative to the bottom surface of the first pallet 3. The x direction of the reference coordinate system is perpendicular to the y axis and the z axis. In addition, the origin of the coordinate of each axis | shaft can be set | placed on the center point of the 1st pallet 3, for example.

  The relative positional relationship between the reference coordinate system and the coordinate system of each glass plate 2 in the present embodiment can be obtained by coordinate conversion processing. That is, as shown in FIG. 18B, the coordinate system of each glass plate 2 moves θx around the x axis, θz rotates around the z axis, and α in the x axis direction, as shown in FIG. It is assumed that the various parameters (θx, θz, α, β) are obtained by the coordinate transformation process, assuming that they are translated and β-translated in the y-axis direction, and the first pallet 3 and each glass plate 2 Can be obtained.

  In this embodiment, the rotational movement θz about the z-axis is taken into account, but the rotational movement θx about the x-axis is restricted by the pallet 3 and the influence can be ignored (θx is always constant). θz, α, β) is obtained by a coordinate conversion process, and the relative positional relationship between the reference coordinate system of the first pallet 3 and the coordinate system of the glass plate 2 is obtained. Further, the influence of the γ parallel movement in the z-axis direction is negligible since the glass plate 2 is supported by the pallet.

The coordinate conversion process used in the present embodiment is performed using a vector expression called homogeneous conversion as a method of expressing a certain coordinate system by a 4 × 4 matrix. Here, in the present embodiment, the shape of the end surface 201 of the glass plate 2 in the longitudinal direction can be simply approximated by a quadratic expression (y = f (x) = Ax ² + Bx), and expressed by Expression (1). can do.

Here, x _m3 , y _m3 , and z _m3 are the x coordinate, y coordinate, and z coordinate in the coordinate system of the glass plate 2.

  Also, the relationship of the new coordinate system created by rotating θz around the z-axis relative to the reference coordinate system, α-translation in the x-axis direction, and β-translation in the y-axis direction is expressed by Equation (2). It is known that

  Therefore, in this embodiment, based on the three bright spots P3, P4, and P5 that are the imaging results of the imaging unit 22d, the parameters (θz, α, β) can be determined from Equation (1) and Equation (2), and the relative positional relationship between the reference coordinate system and the glass plate 2 coordinate system, which is a transparent workpiece, can be obtained.

That is, by obtaining the coordinates P3 (x _w3 , y _w3 , z _w3 ) in the reference coordinate system of the bright spot P3 from the imaging result of the imaging unit 22d, a mathematical formula is obtained from the coordinates P3 (x _w3 , y _w3 , z _w3 ). When (1) and Equation (2) are applied, the following Equation (3) is obtained.

The coordinates P4 (x _w4 , y _w4 , z _w4 ) and the luminescent spot P5 (x _w4 , y _w5 , z _w5 ) in the reference coordinate system of the luminescent spots P4 and P5 are expressed in the same manner as the luminescent spot P3. It is obtained from the relationship 3). Next, when the mathematical expression (3) is expanded, the simultaneous equations of the following mathematical expression (4) are obtained.

By solving these simultaneous equations, the parameters (θz, α, β) of the homogeneous transformation matrix and the respective x coordinates (x _m3 , x _m4 , x _m5 ). Accordingly, by obtaining the relative positional relationship between the reference coordinate system and the coordinate system of the glass plate 2 that is the transparent workpiece, the deviation of the glass plate 2 that is the transparent workpiece from the reference position in the first pallet 3 is obtained. (Movement amount) can be obtained. Here, the reference position is, for example, the position of the glass plate 2 in the first pallet 3 (reference coordinate system) assumed when the teaching data of the robot 22 is set in advance. Note that the teaching data set in advance assuming that a glass plate exists at the reference position is based on the actual position of the glass plate 2 (hereinafter referred to as the actual glass plate 2) based on the calculation result of the deviation (movement amount) from the reference position. , Referred to as “actual position”). Therefore, the reference position does not have to be a position where the glass plate 2 is actually arranged in the first pallet 3, and is a temporary position that can be appropriately determined in the first pallet 3. For example, a fixed point in the first pallet 3 such as the origin of the reference coordinate system placed at the center point of the first pallet 3 can be set as the reference position. In this case, the amount of movement of the glass plate 2 from the reference position is not only the offset amount associated with the plurality of glass plates 2 being arranged in a laminated state at a predetermined interval, but also the position of each glass plate and Includes variations due to posture. Unlike the present embodiment, when teaching data is set for each of a plurality of glass plates 2 arranged in a laminated state, each glass is replaced with a fixed point in the first pallet 3 as a reference position. A reference position may be set for each of the plates 2.

If the glass plate 2 does not move in the z-axis direction and the θx rotational movement around the x-axis can be ignored as in the present embodiment, the basic coordinates are obtained as shown in the equation (4). The z coordinate (z _w3 , z _w4 , z _w5 ) of the system is equal to the z coordinate (z _m3 , z _m4 , z _m5 ) of the coordinate system of the glass plate 2. For this reason, the z coordinates (x _w3 , x _w4 , x _w5 ) are not necessary for obtaining the parameters (θz, α, β), and therefore the coordinates of the bright spots P3, P4, P5 are obtained from the imaging result. In particular, it is not necessary to obtain the z coordinate (z _m3 , z _m4 , z _m5 ).

  As described above, after detecting the position of the glass plate 2 that is the transparent workpiece with respect to the first pallet 3, the teaching data of the robots 10a and 10b is corrected. That is, since the teaching data of the robots 10a and 10b is set on the premise that the glass plate 2 is at the reference position in the first pallet 3, the teaching data in the first pallet 3 of the glass plate 2 which is a transparent workpiece is used. Based on the deviation from the reference position, the teaching data of the robots 10a and 10b can be corrected.

  In addition, although the shape of the longitudinal direction of the end surface 201 of the glass plate 2 was approximated like Formula (1) simply, it is not limited to Formula (1), and it corresponds to the shape of the end surface 201 of the glass plate 2. Or a table showing the correspondence between coordinates expressed on the end surface 201 of the glass plate 2 can be used.

  Further, the homogeneous transformation matrix T is not limited to the mathematical formula (2), and it is well known that it can be deformed depending on the relative positional relationship between the reference coordinate system and the coordinate system of the glass plate as the transparent workpiece.

  The workpiece position detection system 20 of the present embodiment configured as described above performs processing as follows.

  FIG. 19 is a flowchart showing the processing contents of the work position detection system 20 of the present embodiment.

  As shown in FIG. 15, the controller 11 includes a first light projecting unit 21e set to irradiate the slit light 100e in parallel with the x axis and a second light projecting set to irradiate in parallel to the y axis. By transmitting the irradiation signal to the light unit 21f, the first light projecting unit 21e and the second light projecting unit 21f are instructed to irradiate the slit light 100e and the slit light 100f (step S31).

  Next, while the controller 11 irradiates the slit light 100e and the slit light 100f to the first light projecting unit 21e and the second light projecting unit 21f, the controller 11 is positioned above the first pallet 3 so as to capture the xy plane. By transmitting an imaging signal to the set imaging unit 22d, the imaging unit 22d is instructed to capture an image of the glass plate 2 that is a transparent workpiece, that is, a plurality of bright spots (step S32). And the controller 11 takes in the data signal of the imaging result from the imaging part 22d (step S33).

  Next, the controller 11 determines whether or not the three bright spots P3, P4, and P5 generated at the location of the end surface 201 of the glass plate 2 that is the position detection target are confirmed from the captured imaging results (step S1). S34). Specifically, as shown in FIG. 2, the second light projecting unit 21 f irradiates the slit light 100 f so as to intersect the end surface 201 of the glass plate 2 at one intersection in parallel with the y-axis direction. Therefore, the bright spot P5 is always generated on the end surface 201 of the glass plate 2. Therefore, the controller 11 determines whether or not the slit light 100e from the first light projecting portion 21e intersects the end surface 201 of the glass plate 2 at two intersections and the bright spots P3 and P4 are generated.

  Here, the bright spots P3, P4, and P5 are extracted, for example, by selecting a pixel having a pixel value (luminance) greater than or equal to a predetermined value from the data signal (captured image) of the imaging result. In addition, due to the end face of the glass plate 2 being a workpiece having a width, each of the bright spots P3, P4, and P5 may have a certain extent as shown in FIG. In this case, predetermined representative points can be extracted in each area occupied by the respective bright spots P3, P4, and P5, and the coordinates of these representative points can be used as the coordinates of the respective bright spots P3, P4, and P5. . For example, the pixel located at the center in the area occupied by the bright spot P3 may be used as the representative point of the bright spot P3, and the pixel located at the outermost edge in the area occupied by the bright spot P3 may be used as the representative point of the bright spot P3. Good.

  As shown in FIG. 2, a plurality of glass plates 2 are accommodated in the first pallet 3. Therefore, when the second light projecting unit 21f irradiates the slit light 100f in the stacking direction of the glass plates 2 (y-axis direction shown in FIG. 4), the slit light 100f intersects the plurality of glass plates 2 and each glass Bright spots can occur at the end face of the plate 2. As a result, there are cases where there are bright spots generated on the glass plate 2 that is currently subject to position detection for support and bright spots generated on the other glass plates 2. Therefore, even if only the bright spot generated in the glass plate 2 that is the position detection target is determined by the coordinate (y coordinate) along the stacking direction, and this bright spot is extracted as the bright spot P5 by the slit light 100f. Good. In addition, the range of the imaging region and the detection region is limited to the vicinity of the glass plate 2 that is the position detection target by image processing or the like so as not to detect the bright spot generated on the glass plate 2 that is not the position detection target. May be.

  When the three bright spots P3, P4, and P5 are not confirmed on the end surface 201 of the glass plate 2 that is the position detection target (step S34: No), using the moving unit 23, the fixed size of the first light projecting unit 21e is determined. The movement is instructed (step S35). Therefore, the irradiation position of the slit light 100e from the first light projecting unit is changed, and the data signal of the imaging result of the imaging unit 22d is newly captured, and three bright spots are generated on the end surface 201 of the glass plate 2 that is the position detection target. The processing of step S33 to step S35 is repeated until it is confirmed.

  In addition, when the 1st light projection part 21e is moved by the moving part 23 and three luminescent spots P3, P4, and P5 are confirmed by the end surface 201 of the glass 2 which is a position detection object, it is additionally the same It can also be designed to move the first light projecting part 21e in the direction. In this case, the distance between the bright spots P3, P4, and P5 can be increased, and the position detection accuracy of the workpiece can be improved.

  On the other hand, when the three bright spots P3, P4, and P5 can be confirmed on the end surface 201 of the glass plate 2 that is the position detection target (step S34: Yes), the controller 11 performs a coordinate conversion process (homogeneous conversion). The routine is read (step S36). That is, in this embodiment, the coordinate system of the glass plate 2 is premised on the coordinate system of the glass plate 2 rotating θz around the z axis, α translating in the x axis direction, and β translating in the y axis direction. Therefore, the homogeneous transformation matrix T (see formula (2)) suitable for the conditions of the present embodiment is read out.

  The controller 11 takes in values of reference coordinates (hereinafter referred to as “reference coordinate system values”) in the reference coordinate system of the first pallet 3 of the bright spots P3, P4, P5 (steps S37 to S39).

  As described above, the controller 11 solves each parameter (θz, α, β) by solving the simultaneous equations using the reference coordinate system value, the homogeneous transformation matrix T, and the expression representing the shape of the end face of the glass plate. ) Can be calculated (steps S40 to S42).

  After the controller 11 calculates the values of the parameters (θz, α, β), the parameters (θz, α, β) are set so that the robots 10a, 10b can support the glass plate 2 at the actual position. Is converted into coordinates in the coordinate system of the robots 10a and 10b (hereinafter referred to as "robot coordinates") (step S43). That is, each parameter (θz, α, β) represents a relative positional relationship from the reference coordinate system to the coordinate system of the glass plate 2, so that each parameter (θz, α, β) The amount of movement between the expressed reference position and the actual position expressed in the coordinate system of the glass plate 2 can be obtained. Next, the movement amount from the reference position to the actual position based on each parameter (θz, α, β) is converted into the coordinates of the robot coordinate system. As an example, when the glass plate 2 is at the reference position of the origin of the reference coordinate system and a predetermined posture, for example, when the coordinate axis of the reference coordinate system coincides with the coordinate axis of the glass plate 2, each parameter (θz , Α, β) is the amount of movement from the reference position to the actual position itself, and the value of this parameter can be converted into coordinates in the robot coordinate system.

  The controller 11 calculates a correction amount of teaching data (hereinafter referred to as “robot support correction amount”) in order for the robots 10a and 10b to support the glass plate 2 at the actual position based on the robot coordinates (step “hereinafter referred to as“ robot support correction amount ”). S44). For example, the teaching data is set based on the reference position described above. Accordingly, when the glass plate 2 is in the actual position in the first pallet 3, the location where the robots 10a and 10b support the glass plate 2 also changes. Therefore, the controller 11 calculates the correction amount of the teaching data based on the robot coordinates so that the robots 10a and 10b can accurately support the glass plate 2 at the actual position.

  The controller 11 corrects the teaching data of the robots 10a and 10b based on the robot support correction amount, and causes the robots 10a and 10b to support the glass plate 2 (step S45).

  In the above process, the process of step S34 corresponds to the process of the determination unit that determines whether or not the slit light 100e intersects the end surface 201 of the glass plate 2 that is a transparent workpiece at two intersections. Moreover, the process of step S35-step S42 respond | corresponds to the process of the detection part which detects the position of the glass plate 2 which is a transparent body work based on the imaging result by the imaging part 22d. Further, in the processing of step S43 to step S44, the teaching data of the robots 10a and 10b for supporting the glass plate 2 which is a transparent workpiece is obtained by comparing the reference coordinate system of the first pallet 3 with the coordinate system of the workpiece. This corresponds to the processing of the correction unit that performs correction based on the correct positional relationship.

  As described above, according to the workpiece position detection system 20 of the third embodiment, in addition to the effects (A), (B), (H) to (J) of the first embodiment, the following (N ) To (Y) effects.

  (N) At least one light projecting unit that irradiates slit light so as to intersect the end surface of the glass plate that is a transparent body, and an imaging unit that images a plurality of bright spots generated at a plurality of locations on the end surface of the glass plate by the slit light And a detection unit that detects the position of the glass plate based on the imaging result of the imaging unit, the position of the glass plate that is a transparent body can be accurately detected.

  (O) Since a plurality of light projecting portions are provided, a plurality of bright spots are generated on the end surface of the workpiece for use in workpiece position detection, and the position of the glass plate that is a transparent body is determined based on the plurality of bright spots. It can be detected in detail.

  (P) Since the position of the glass plate is detected based on the imaging results of a plurality of bright spots generated at a plurality of locations on the end surface of the glass plate by the respective slit lights irradiated from the plurality of light projecting units, Can be detected in more detail.

  (Q) The glass plate has a curved end surface capable of forming a plurality of intersections with respect to one slit light irradiated from one light projecting unit, and the detection unit has a brightness generated at the plurality of intersections. Since the position of the glass plate is detected based on the imaging results of a plurality of bright spots including at least a point, the position of the glass plate can be detected even when the glass plate has a curvature.

  (R) The glass plate is stored in a pallet in a stacked state at a predetermined interval, and the detection unit is positioned on the basis of the imaging result captured by the imaging unit while being stored in the pallet. Therefore, a plurality of glass plates on the pallet can be sequentially detected.

  (S) Even if the pallet is a pallet for transportation used for transporting glass plates, conventionally, when a robot supports a workpiece such as glass, an operator such as taking out the glass plate from the pallet during transportation. Although a process was required, the robot can accurately support the glass plate even with the pallet during transportation, so that the glass plate can be prevented from falling.

  (T) The detection unit uses the coordinate system in the pallet as the reference coordinate system, and obtains the relative positional relationship between the reference coordinate system and the coordinate system of the glass plate using a plurality of bright spots. Such a positional relationship can be easily obtained by performing the homogenous transformation of the prior art.

  (U) Since there is a correction unit that corrects the teaching data of the robot for supporting the glass plate based on the positional relationship, the teaching data of the robot can be corrected so that the position of the glass plate can be accurately supported. Become.

  (V) A first light projecting unit that irradiates one slit light that intersects the end surface of the glass plate at two intersections, and another slit light that intersects the end surface of the workpiece at another portion of the end surface of the workpiece. Including a second light projecting unit, and the detection unit includes a bright spot generated at two intersections where one slit light and the end face of the glass plate intersect, a bright spot generated at the two intersections, and other locations. Since the position of the glass plate is detected based on the imaging result of a plurality of bright spots including the bright spot generated by the slit light, the number of the light projecting parts is reduced with respect to the number of bright spots, and the position of the glass plate is determined. Can be detected.

  (W) Since the 1st light projection part irradiates the slit light which cross | intersects the end surface of a glass plate in the one place pinched | interposed into two intersections, three points of bright spots which arise on the end surface of a glass plate are set to predetermined distance You will be able to have.

  (X) Furthermore, by having a moving part which moves at least one light projection part so that one slit light may cross | intersect the end surface of a glass plate in several places, the glass plate which is a position detection object is in a pallet. Even in a stationary state, the glass plate can be detected.

  (Y) A determination unit that determines whether or not one slit light intersects the end surface of the glass plate at two intersections, and one slit light at the two intersections with the end surface of the workpiece based on the determination result of the determination unit Since it has the moving part which moves a 1st light projection part so that it may cross | intersect, a glass plate does not move and it becomes possible to obtain three bright spots with two light projection parts.

<Fourth Embodiment>
Furthermore, a fourth embodiment of the present invention will be described in detail.

  As shown in FIG. 20, the work position detection system 20 of the fourth embodiment includes a third light projecting unit 21g, a fourth light projecting unit 21h, and an image capturing unit 22e in addition to the components of the third embodiment. By using this system, it is possible to detect a three-dimensional posture of a workpiece that is a transparent body based on imaging results from a plurality of directions.

  The first light projecting unit 21e and the second light projecting unit 21f irradiate so as to cross the xy plane, and the third light projecting unit 21g and the fourth light projecting unit 21h irradiate so as to intersect the yz plane.

  According to the workpiece position detection system 20 of the fourth embodiment, by applying the above-described method based on the bright spot generated at the location where the slit light from each light projecting unit and the workpiece intersect, The three-dimensional posture of the workpiece can be easily obtained.

  As described above, according to the workpiece position detection system 20 of the fourth embodiment, (A), (B), (H) to (J) of the first embodiment, and (N) of the third embodiment. In addition to the effects (Y), the following effects (Z) are achieved.

  (Z) A plurality of sets of light projecting units and imaging units are provided, and the detection unit detects the three-dimensional posture of the workpiece based on the imaging results from a plurality of directions by the plurality of imaging units, thereby setting the position of the workpiece to 3 It becomes possible to detect with a dimensional posture.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described in detail.

  In the first embodiment and the second embodiment of the present invention described above, the end face of the workpiece that emits light by the illumination light emitted by the illumination light projecting unit is imaged by the imaging unit, and the workpiece is recognized from the imaging result. The premise is that it can be done.

  However, when the workpiece position detection system of the present invention is used, for example, in an actual factory, light outside the light, that is, light such as sunlight, and other than light emitted by the light projecting unit is completely controlled. Is impossible, and ambient brightness changes due to external light. When the ambient brightness changes, the contrast value and brightness of the image captured by the imaging unit also change, and as a result, the workpiece may not be easily recognized. For example, if the contrast value of the image is reduced due to the difference between the brightness of the light emitting part and the ambient brightness due to the light emitted by the light projecting unit, it becomes difficult to recognize the workpiece from the image captured by the imaging unit, Alternatively, if the surrounding brightness is too bright and the brightness of the entire image becomes high, halation occurs, making it difficult to recognize the workpiece from the image captured by the imaging unit.

  Moreover, not only the influence of external light but also the light projecting unit itself may deteriorate over time, so that the amount of light emitted by the light projecting unit may decrease, making it difficult to recognize the workpiece from the image captured by the image capturing unit.

  On the other hand, for example, when a contrast value of an image that is excessive for recognizing a workpiece is obtained, it is desirable to extend the life of the light projecting unit by reducing the amount of light irradiated by the light projecting unit.

  A workpiece position detection system according to a fifth embodiment of the present invention solves the above problem. The workpiece position detection system according to the present embodiment includes an irradiation light amount adjustment unit that adjusts the amount of light emitted by the light projecting unit, and a captured light amount adjustment unit that adjusts the amount of light captured by the imaging unit. It is possible to adjust the light projecting unit and the imaging unit used in the second embodiment and the second embodiment. The irradiation light amount adjustment unit changes the amount of light emitted from the light projecting unit to prevent the workpiece from becoming difficult to recognize. The captured light amount adjustment unit changes the amount of light captured by the imaging unit to make the workpiece difficult to recognize. It is to prevent the situation.

  Hereinafter, the workpiece position detection system 20 of the fifth embodiment will be described in detail.

  As illustrated in FIG. 21, the workpiece position detection system 20 according to the fifth embodiment includes a light projecting unit 21, an imaging unit 22, an irradiation light amount adjusting unit 31, a captured light amount adjusting unit 32, and a controller 11. It is out. The present embodiment is the same as the configuration used in the first embodiment and the second embodiment, except for the configuration that executes the adjustment processing of the irradiation light amount and the adjustment processing of the captured light amount of the imaging unit. Accordingly, in FIG. 21, the repeated description of the configuration of the robot 10 a for accommodating the glass plate, the pallet 4, and the like is omitted, and only the configuration related to the adjustment processing of the irradiation light amount and the adjustment processing of the captured light amount of the imaging unit. It is shown.

  Hereinafter, based on FIG. 21, the light projecting unit 21, the irradiation light amount adjusting unit 31, the imaging unit 22, the captured light amount adjusting unit 32, and the controller 11 constituting the work position detection system 20 of the fifth embodiment are sequentially described. explain.

<Light projecting part>
The light projecting unit 21 is an illumination light projecting unit that emits illumination light, and the light projecting unit itself is the same as the illumination light projecting unit 21a used in the first embodiment. The amount of light emitted by the light projecting unit 21 is adjusted by the irradiation light amount adjusting unit 31.

As shown in FIG. 21, the light projecting unit 21 emits illumination light obliquely onto the surface of the glass plate 2 and concentrates the light on the end surface of the glass plate 2, as in the first embodiment. Let
<Irradiation light amount adjustment unit>
The irradiation light amount adjusting unit 31 adjusts the light amount irradiated by the light projecting unit 21 and is also called a light controller. Since the configuration itself for adjusting the amount of irradiation light is the same as the conventional one, a detailed description is omitted. For example, it has a circuit configuration for controlling the power supplied to the illumination load by controlling the phase of the triac. For example, the irradiation light amount adjusting unit 31 can adjust the light amount level in a plurality of stages from the minimum level to the maximum level.

  The irradiation light amount adjusting unit 31 of the present embodiment is configured to adjust the light amount irradiated by the light projecting unit 21 based on the brightness / darkness data of the images captured by the imaging unit 22 until the previous time in cooperation with the controller 11. It is. Here, the brightness data includes the contrast value corresponding to the difference in brightness in the entire captured image, the average brightness of the entire screen (hereinafter referred to as “screen brightness”), which is the brightness of the entire image, The average lightness of the entire recognition unit (hereinafter, referred to as “recognition unit lightness”), which is the brightness of the light emission part, that is, the light concentration part generated on the end face of the glass plate 2 is included.

  Specifically, the irradiation light amount adjustment unit 31 receives from the controller 11 an instruction signal as to whether to increase or decrease the amount of light emitted by the light projecting unit 21, and determines the amount of light emitted by the light projecting unit 21 according to the instruction signal. Adjust. Note that the irradiation light amount adjustment unit 31 desirably adjusts the light amount based on the average value of the brightness data of a plurality of images captured by the imaging unit until the previous time. Such an irradiation light amount adjusting unit 31 may be incorporated in the light projecting unit 21.

<Imaging unit>
The imaging unit 22 is an imaging unit that captures an area where the light generated on the end surface of the glass plate 2 is concentrated, and is, for example, a camera. The imaging unit itself is the same as the imaging unit 22a used in the first embodiment. The imaging unit 22 is equipped with an actuator (not shown), and the shutter speed and the aperture can be appropriately adjusted by controlling the actuator. The amount of light captured by the imaging unit 22 is adjusted by the captured light amount adjustment unit 32.

  As shown in FIG. 21, the imaging unit 22 has a light concentration point Q <b> 1 generated on the end surface of the glass plate 2 when the light projecting unit 21 irradiates the glass plate 2, as in the first embodiment. Image.

<Capture light intensity control unit>
The captured light amount adjusting unit 32 constitutes a vision system (visual system) together with the imaging unit 22 described above.

  The captured light amount adjustment unit 32 roughly includes a light / dark data calculation unit for calculating light / dark data from a captured image and a captured light amount control unit for controlling the captured light amount.

  The captured light amount adjustment unit 32 serving as a brightness / darkness data calculation unit receives an image captured by the imaging unit 22 and calculates brightness / darkness data such as the above-described contrast value, screen brightness, and recognition unit brightness from the image. is there. Note that the calculation of the contrast value, the screen brightness, and the recognition unit brightness itself is the same as that of a general image processing technique, and thus detailed description thereof is omitted. Brightness data itself such as the calculated contrast value, screen brightness, and recognition unit brightness is sent to the controller 11 as a vision measurement result. The transmitted brightness / darkness data is stored in the controller 11 as history data.

  Further, the captured light amount adjustment unit 32 as a light amount control unit cooperates with the controller 11 to adjust the light amount captured by the imaging unit 22 based on the brightness data of the images captured by the imaging unit 22 until the previous time. It is. Specifically, the captured light amount adjustment unit 32 receives an instruction signal indicating whether to increase or decrease the light amount captured by the imaging unit 21 from the controller 11 and adjusts the light amount captured by the imaging unit 22 based on the instruction signal. And controlling the shutter speed and aperture of the imaging unit.

  Specifically, the captured light amount adjusting unit 32 adjusts the light amount by controlling the shutter speed and / or the aperture of the imaging unit 22. If the shutter speed of the imaging unit 22 is slowed down to increase the time during which the shutter is open, the time that the light hits can be increased, so that more light can be taken in, and the shutter speed of the imaging unit 22 can be increased. If the shutter opening time is shortened, the light exposure time is shortened and the amount of light taken in is reduced. Further, regarding the diaphragm, if the lens aperture of the image pickup unit 22 is increased, a large amount of light is captured. On the other hand, if the lens aperture is decreased, the amount of light captured is small. .

  For example, the irradiation light amount adjustment unit 31 can adjust the shutter speed in a plurality of steps from the slowest level to the fastest level, and adjusts the apertures of the lens apertures in a plurality of steps from the minimum opening level to the maximum opening level. be able to.

  Note that it is desirable that the amount-of-capture light amount adjustment unit 32 adjust the amount of light that is captured based on the average value of the brightness data of a plurality of images captured by the imaging unit until the previous time.

  Such an irradiation light amount adjustment unit 31 may be built in the imaging unit 22.

<Controller>
In the work position detection system 20 of the fifth embodiment, the controller 11 further functions as the calculation unit 110, and the CPU of the controller 11 plays the role. The controller 11 also has functions as a parameter storage unit 111 and a past data storage unit 112, and a memory (RAM memory, nonvolatile memory) plays the role of these.

  The parameter storage unit 111 stores the initial value of the light amount of the light projecting unit 21 and the lower limit and upper limit set values of the desired range of the contrast value and brightness of the image. The predetermined range of the contrast value and the brightness of the image is a range in which the controller 11 can recognize the bright spot emitted from the end surface of the workpiece by the image captured by the imaging unit, for example.

  The past data storage unit 112 stores the contrast value and brightness of images captured by the imaging unit 22 up to the previous time as past data. The contrast value and brightness of the image up to the previous time are calculated by, for example, the calculation unit 110 (CPU).

  Based on the various setting values stored in the parameter storage unit 111 and the initial value of the light intensity of the light projecting unit, and the past data stored in the past data storage unit 112, the calculation unit 110 stores the past data. Whether the contrast value in the desired range and the lightness in the desired range are calculated, and the processing content is instructed to the irradiation light amount adjustment unit 31 and the captured light amount adjustment unit 32 based on the calculation result. Here, it is desirable that the calculation unit 110 calculates the average value of the contrast value and the brightness of the past data for a plurality of times until the previous time, and calculates whether the average value is the contrast value and the brightness of a desired range.

  The calculation unit 110 also plays a role of calculating a contrast value and a brightness value from the image data transmitted by the captured light amount adjustment unit 32.

  The workpiece position detection system 20 of the fifth embodiment configured as described above performs processing as follows.

  22a and 22b are flowcharts showing the processing contents of the workpiece position detection system 20 of the present embodiment. The following processing content is processing for adjusting the amount of light emitted by the light projecting unit based on the average value of the brightness data of a plurality of images captured by the imaging unit until the previous time, and detects the work position. Since the processing itself can be performed in the same manner as the above-described embodiment, the description of the processing content is omitted.

  First, in steps S51 to S55, processing is performed until data of an image captured by the imaging unit is acquired.

  The controller 11 sets the initial value of the light amount of the light projecting unit 21, the lower limit setting value (hereinafter referred to as “lower limit setting value”) and the upper limit setting value (hereinafter referred to as “upper limit setting”) of the desired range of contrast value and brightness. (Referred to as “value”) is initialized (step S51). Here, the lower limit set value of the contrast value is P1, the upper limit set value of the contrast value is P2, the lower limit set value of the brightness is P3, and the set value of the brightness upper limit is P4. As long as the desired contrast value range can be set to 0 to 100, for example, the desired range is 30 to 70, the lower limit set value P1 is 30, and the upper limit set value P2 is 70. The desired range of brightness is the same as the setting of the desired range of contrast value.

Next, the irradiation unit 21 is instructed to irradiate the illumination light (step S52), and the imaging unit 22 is instructed to image the bright spot on the end face of the glass plate 2 irradiated by the illumination light from the projection unit 21 (step S52). Step S53)
Next, the image data captured by the image capturing unit 22, for example, the contrast value and brightness of the image are captured and stored as a history (step S54). Then, the average value A and the lightness average value B of the stored contrast values for the previous n times are calculated (step S55).

  As described above, when the processing up to the acquisition of the data of the image captured by the imaging unit is completed, the processing of the capture light amount adjustment unit and the irradiation light amount adjustment unit is then performed as shown in Steps S56 to S69. The That is, a process of adjusting the light amount emitted by the light projecting unit 21 or the light amount captured by the image capturing unit 22 is executed based on the brightness / darkness data of the images captured by the image capturing unit 22 until the previous time.

  In the present embodiment, when the set value of the amount of light irradiated by the current light projecting unit 21 is the maximum set value, the average value A of the contrast values for a plurality of times is the lower limit value P1 or less, or the average value B of the brightness is the lower limit value. If it is less than or equal to P3, the shutter speed is lowered by one step in order to increase the amount of light taken in.

  On the other hand, when the current setting value of the amount of light emitted by the light projecting unit 21 is the minimum setting value P5, the average value A of the contrast values for a plurality of times is the upper limit value P2 or more, or the lightness average value B is the upper limit value P4 or more. If so, processing is performed to increase the shutter speed by one step in order to reduce the amount of captured light.

  In addition, when the current setting value of the light amount irradiated by the light projecting unit 21 is neither the maximum setting value nor the minimum setting value, that is, when the minimum setting value <the setting value of the light amount <the maximum setting value, the irradiation light amount Therefore, if the average value A of the contrast values for a plurality of times is less than or equal to the lower limit value P1, processing for increasing the light amount by a certain amount is performed, and the average value A of the contrast values for a plurality of times is greater than or equal to the upper limit value P2. If so, a process of reducing the amount of light by a certain amount is performed.

  Here, the minimum light intensity setting value P5 is the minimum value of the light intensity emitted by the light projecting unit 21 to the extent that the workpiece can be recognized from the image captured by the imaging unit 22. As a specific example, the captured light amount adjustment unit 32 is variable in brightness level from 1 to 10 levels except when the light projecting unit 21 is turned off, and is bright enough to recognize a workpiece in 3 levels or more. Assuming that there are 10 steps, the maximum set value of the light amount is set, and at the 3 steps, the minimum set value P5 of the minimum amount of light is set.

First, in step S56 of FIG. 22, it is determined whether or not the current setting value of the amount of light irradiated by the light projecting unit 21 is maximum. If the current setting value of the amount of light irradiated by the light projecting unit 21 is the maximum (step S56: Yes), the process proceeds to step S57. If the setting value of the amount of light to be irradiated is not the maximum (step S56: No), it proceeds to step S61.
[Processing when the current setting value of the amount of light emitted by the light projecting unit 21 is maximum]
Processing when the current set value of the amount of light irradiated by the light projecting unit 21 is maximum will be described. When the set value of the light amount irradiated by the current light projecting unit 21 of the current light projecting unit 21 is the maximum (step S56: Yes), the process of the read light amount adjusting unit is executed. Based on the average value A of the contrast values of the captured images for n times and the average value B of the brightness values for n times of imaging, a process of increasing the amount of light captured by the imaging unit 22 by reducing the shutter speed by one step is executed. Is done.

  First, a process of comparing the average value A of the contrast values of n images captured so far with the lower limit set value P1 set as the lower limit of the desired contrast value is executed (step S57). As a result of the comparison, when the average value A of the contrast values of the images for n times of imaging exceeds the lower limit setting value P1 of the desired contrast value (step S57: No), further, for n times of imaging imaged so far. A process of comparing the average value B of the brightness of the image with the lower limit set value P3, which is a set value of the lower limit of the desired brightness, is executed (step S58). Of course, the processing order of step S57 and step S58 can be interchanged.

  As a result of the comparison processing in step S57 and step S58, when the average value A of the contrast values of the images for n times of imaging is less than or equal to the lower limit set value P1 of the desired contrast value (step S57: Yes), or for n times of imaging When the average value B of the lightness of the image is equal to or lower than the desired lightness lower limit setting value P3 (step S58: Yes), the current light amount setting value is already the maximum, and the light amount cannot be increased any more. Regardless, it corresponds to a state where the average value A of contrast values and the average value B of lightness are equal to or lower than an allowable lower limit set value. Therefore, since it is determined that it is necessary to increase the amount of captured light, the captured light amount adjustment unit 32 is instructed to decrease the shutter speed by one step (step S59).

  As the shutter speed changes, the light amount can be changed to a set value that matches the shutter speed (step S60). In this way, the amount of light is changed to the set value according to the shutter speed. Since the amount of captured light increases as the shutter speed is lowered, the lower limit set value P1 of the contrast value and the lower limit set value P3 of the brightness value are increased. This is because it is possible to reduce the amount of light emitted by the light projecting unit 21 or to reduce the amount of light.

  Specifically, depending on the system to be used, for example, the relationship between the shutter speed and the amount of light captured (or the contrast value and lightness according to the amount of light captured), the relationship between the light amount and the contrast value and lightness, In addition, the amount of change in the amount of light can be determined from the difference between the contrast values and the average values A and B of the brightness and the lower limit setting values P1 and P3. As a simple method, the shutter speed is lowered by one step. In that case, a predetermined amount of light may be reduced. Note that the process of step S60 may be omitted.

  As described above, when the processing for adjusting the amount of captured light (step S57 to step S60) is completed based on the average value of contrast values and the average value of brightness of n images, the process proceeds to step S70.

  Note that the average value A of the contrast values of the images for n times of imaging is larger than the lower limit setting value P1 (step S57: No), and the average value B of the lightness values of the images for n times of imaging is larger than the lower limit setting value P2. In such a case (step S58: No), it is determined that sufficient contrast and brightness are obtained, and the process proceeds to step S70 as it is.

  On the other hand, when the current light intensity setting value of the light projecting unit 21 is not the maximum (step S56: No), the current light intensity setting value of the light projecting unit 21 is lowered to the minimum setting value P5. It is determined whether or not (step S61). Here, as described above, the minimum light amount setting value P5 is the minimum value of the light amount irradiated by the light projecting unit 21 to the extent that the workpiece can be recognized from the image captured by the image capturing unit 22.

  And as a result of this determination, when the set value of the light amount irradiated by the current light projecting unit 21 has already been lowered to the minimum set value P5 (step S61: Yes), the process proceeds to step S62, When the set value of the light amount irradiated by the light projecting unit 21 is not the minimum set value P5 (step S61: No), the process proceeds to step S66.

[Processing when the current setting value of the amount of light emitted by the light projecting unit 21 is the minimum setting value P5]
When the current set value of the amount of light emitted by the light projecting unit 21 is already the minimum set value P5 (step S61: Yes), the processing of step S62 to step S65 is executed.

  First, a process of comparing the average value A of the contrast values of n images captured so far with the upper limit set value P2 set as the upper limit of the desired contrast value is executed (step S62). As a result of the comparison, when the average value A of the contrast values of the images for n times of imaging is below the upper limit setting value P2 of the desired contrast value (step S62: No), further, for n times of imaging that have been imaged so far A process of comparing the average value B of the brightness of the image with the upper limit set value P4 that is a set value of the upper limit of the desired brightness is executed (step S63). Of course, the processing order of step S62 and step S63 can be interchanged.

  As a result of the comparison processing in step S62 and step S63, when the average value A of the contrast value of the image for n times of imaging is not less than the upper limit set value P2 of the desired contrast value (step S62: Yes), or for n times of imaging When the average brightness value B of the image is equal to or higher than the desired brightness upper limit setting value P4 (step S63: Yes), the current light intensity setting value is already the minimum, and the light intensity cannot be further reduced. Regardless, it corresponds to a state where the average value A of contrast values and the average value B of brightness are equal to or higher than an allowable upper limit set value. Therefore, since it is determined that it is necessary to reduce the amount of captured light, the captured light amount adjustment unit 32 is instructed to increase the shutter speed by one step (step S64). As the shutter speed changes, the amount of light can be changed to an installation value that matches the shutter speed (step S65). The amount of light is changed to the setting value according to the shutter speed in this way because the amount of captured light decreases as the shutter speed is increased. Therefore, the amount of decrease and the setting value P2 for the upper limit of the contrast value and the setting of the upper limit of the brightness are set. This is because it may be necessary to increase the amount of light emitted by the light projecting unit 21 in consideration of the value P4. Note that the specific details are the same as those described in step S60, and thus detailed descriptions thereof are omitted. Note that the process of step S65 may be omitted.

  The above “processing when the current setting value of the amount of light emitted by the light projecting unit 21 is the maximum” (steps S57 to S60) and “the set value of the amount of light emitted by the current projecting unit 21 are minimum. The processing in a certain case (step S62 to step S65) is the processing of the captured light amount adjustment unit 32, that is, the light amount captured by the imaging unit 22 based on the light / dark data of the images captured by the imaging unit 22 until the previous time. This corresponds to an example of the process to be adjusted (that is,).

[Processing when the current setting value of the amount of light emitted by the light projecting unit 21 is minimum setting value <setting value <maximum setting value]
Next, processing when the current setting value of the amount of light irradiated by the light projecting unit 21 is neither the maximum setting value nor the minimum setting value, that is, the processing when the minimum setting value <the light amount setting value <the maximum setting value is described. To do.

  In the flowcharts of FIGS. 22a and 22b, when the current light amount setting value of the light projecting unit 21 is neither the maximum setting value nor the minimum setting value (step S56: No and step S61: No), the contrast value Is compared with the lower limit set value P1 of the desired contrast value (step S66). As a result of the comparison, if the average value A of the contrast values is equal to or less than the lower limit set value P1 of the desired contrast value (step S66: Yes), the light amount is increased by a certain amount (next step S67). Here, by making the increase in the amount of light constant, it is possible to deal with a gradual change in external light and to enable stable imaging. Further, by making the increase in the amount of light a constant amount, there is an advantage that the processing of the controller 11 is not complicated and the processing speed is increased. However, unlike the present embodiment, it can be configured not to increase the amount of light to a constant amount. For example, the amount of light can be controlled using a parameter table in which the amount of light corresponds to the contrast value, and the amount of light can be adjusted using various methods. After the process of step S67, the process proceeds to step S70.

  When the average value A of the contrast values is not less than or equal to the lower limit set value P1 (step S66: No), the average value A of the contrast values is compared with the upper limit set value P2 of the desired contrast value (step S68). If the average value A of the contrast values is greater than or equal to the upper limit set value P2 as a result of the comparison (step S68: Yes), the light amount is decreased by a certain amount (step S69). The amount of light is not limited to a fixed amount as in the case of increasing the amount of light, and the amount of light can be adjusted using various methods. After the process of step S69, the process proceeds to step S70.

  On the other hand, when the average value A of the contrast values is not lower than the lower limit set value P1 and not higher than the upper limit set value P2 (step S66: No and step S68: No), that is, the lower limit set value P1 <the average of the contrast values. When the value A <the upper limit set value P2, it is determined that the contrast value is good, and the process directly proceeds to step S70.

  Note that the above “processing when the set value of the amount of light irradiated by the light projecting unit 21 is the minimum set value <set value <maximum set value” (steps S66 to S69) is the process of the irradiation light amount adjusting unit. That is, this corresponds to an example of processing for adjusting the amount of light emitted by the light projecting unit based on the brightness data of the images captured by the imaging unit 22 until the previous time.

  Finally, in step S70, it is determined whether or not the measurement is finished. If the measurement is not finished (step S70: No), the process returns to step S52. If the measurement is finished (step S67: Yes), the process is finished. .

  In addition, although the form which combined the irradiation light quantity adjustment part and the taking-in light quantity adjustment part is shown in 5th Embodiment, it is not restricted to a combination, The irradiation light quantity adjustment part or the taking-in light quantity adjustment part is used independently. Is also possible. For example, FIG. 23 shows an example using only the irradiation light amount adjustment unit. Steps S81 to S90 shown in FIG. 23 are the same as steps S51 to S55 and S66 to S70 described above, and thus detailed description thereof is omitted.

  Further, as a modification of the fifth embodiment, instead of the process of changing the shutter speed of the imaging unit 22 (step S59, step S60) in order to increase the captured light quantity in the process of the captured light quantity adjustment unit, imaging is performed. A process of changing the aperture of the unit 22 can be used, or a process of changing both the shutter speed and the aperture can be used.

  Furthermore, in the fifth embodiment, the irradiation light amount adjustment unit adjusts by the contrast value, but is not limited to the contrast value, and adjusts the light amount by comparing the brightness, and uses both the contrast value and the brightness. It is also possible to adjust the amount of light.

  Furthermore, although the fifth embodiment has been described on the assumption that the light emitted from the light projecting unit 21 is irradiation light, the capturing light amount adjusting unit assumes that the capturing light amount is adjusted. Therefore, the present invention is not limited to the irradiation light but can be applied to light such as slit light.

  As described above, according to the workpiece position detection system 20 of the present embodiment, the following effects (a) to (c) are achieved.

  (A) When the ambient brightness changes due to external light and it is difficult to recognize the workpiece, increasing the light intensity of the light projecting unit makes it easier to recognize the workpiece. If the level is higher than possible, it is possible to prevent the work from being difficult to recognize due to halation and to extend the life of the illumination by reducing the light quantity of the light projecting unit. In addition, since this process uses a value obtained by processing the previous value and the previous value, there is an advantage that it does not take extra time such as re-establishing the difference in measurement.

  (B) By adjusting the amount of light emitted by the light projecting unit and / or adjusting the amount of light captured by the imaging unit based on the average value of a plurality of imaging results up to the previous time, a sudden change in light occurs. It is possible to prevent the amount of light from being adjusted according to the imaging result when the

  (C) Even if the light projecting unit itself deteriorates over time, it is possible to prevent the workpiece from being difficult to recognize by adjusting the amount of light captured by the imaging unit.

  As mentioned above, in the 1st-5th embodiment, taking the window glass for vehicles as an example, although the work position detection system was illustrated, it is not limited to a window glass plate for vehicles, and it is made into transparent bodies, such as plastic and glass. Can be applied as well. The first to fifth embodiments can be applied even if the surface of the glass plate does not have a curved surface.

  In the first to fifth embodiments, the workpiece position detection and the robot control are performed by the same controller. However, the present invention is not limited to this. For example, it is also possible to implement the present invention by detecting the workpiece position with another controller and transmitting the result to a controller that controls the robot.

  Furthermore, as in the third embodiment and the fourth embodiment, when a plurality of glasses are stored in a pallet in a laminated state at a predetermined interval, a slit is formed so that bright spots are simultaneously generated in the plurality of glasses. It is also possible to simultaneously detect the positions of a plurality of glasses by irradiating light and imaging results of the plurality of bright spots.

  As described above, by using the present invention, light is emitted so that the end surface of the workpiece, which is a transparent body, emits light, and the light emission location generated on the end surface of the workpiece by the light is imaged, and the position of the workpiece is determined based on the imaging result. Since it detects, the position of the workpiece | work which is a transparent body can be detected now correctly. Further, conventionally, when a workpiece such as glass is handled by a robot, an operator process such as taking out the glass from a pallet during transportation is required. However, by using the present invention, the robot can accurately handle the pallet during transportation. Therefore, since it corresponds to a plurality of vehicle types, it can be constructed with inexpensive equipment, and the personnel cost can be reduced. Knowing the relative position of the robot and glass, it can be applied not only to placing on a pallet, but also to mounting a car body.

2 glass plates,
10a robot,
11 controller,
21a to 21c Floodlight unit,
22a, 22b imaging unit,
100a Illumination light,
100b, 100c slit light,
300 Imaging space.

Claims (13)

At least one light projecting unit that emits light so that the end surface of the work that is a transparent body emits light;
An imaging unit that images a plurality of different light emitting portions generated on the end face of the workpiece by the light;
A detection unit that detects a position of the workpiece based on an imaging result by the imaging unit,
The light projecting unit refers irradiation so as to cross the slit light to an end face of the workpiece,
The imaging unit takes an image at the same time a plurality of bright points caused by multiple 箇 plants of the end face of the workpiece by the slit light in the same field of view,
The workpiece has a curved end surface capable of forming a plurality of intersections with respect to one slit light irradiated from one light projecting unit,
The work position detection system , wherein the detection unit detects a position of the work based on an imaging result of a plurality of bright spots including at least a bright spot generated at the plurality of intersections . A plurality of the light projecting units are provided,
The detection unit detects the position of the workpiece based on imaging results of a plurality of bright spots generated at a plurality of locations on an end surface of the workpiece by the respective slit lights irradiated from the plurality of light projecting units. The workpiece position detection system according to claim 1. The light projecting unit irradiates one slit light that intersects the end surface of the work at two intersections, and another slit that intersects the end surface of the work at another portion of the end surface of the work. A second light projecting unit that emits light,
The detection unit is generated by the other slit light generated at the two intersections where the one slit light and the end face of the workpiece intersect, the bright point generated at the two intersections, and the other spot. work location system according to claim 1 or 2, characterized in that to detect the position of the workpiece based on the imaging results of a plurality of bright points and a bright spot was. The work position detection system according to claim 3 , wherein the second light projecting unit irradiates slit light that intersects an end face of the work at one place between the two intersections. The work position detection system according to claim 1 , further comprising a moving unit that moves at least one light projecting unit so that one slit light intersects the end surface of the work at a plurality of locations. Further, a determination unit that determines whether or not the one slit light intersects the end surface of the workpiece at two intersections;
And a moving unit that moves the first light projecting unit so that the one slit light intersects the end surface of the workpiece at two intersections based on a determination result of the determining unit. The work position detection system according to claim 3 . At least one light projecting unit that irradiates slit light so as to intersect with the end face of the work so that the end face of the work that is a transparent body emits light;
An imaging unit that images a plurality of different light emission points generated on the end surface of the workpiece by the slit light;
A detection unit that detects a position of the workpiece based on a result of imaging by the imaging unit;
A moving unit that moves at least one of the light projecting units so that one slit light intersects the end surface of the workpiece at a plurality of locations ;
The imaging unit images a plurality of bright spots generated at a plurality of locations on the end surface of the workpiece by the slit light ,
The workpiece has a curved end surface capable of forming a plurality of intersections with respect to one slit light irradiated from one light projecting unit,
The work position detection system , wherein the detection unit detects a position of the work based on an imaging result of a plurality of bright spots including at least a bright spot generated at the plurality of intersections . Irradiating a first light projecting portion that irradiates one slit light that intersects the end surface of the workpiece, which is a transparent body, at two intersections, and another slit light that intersects the end surface of the workpiece at other locations on the end surface of the workpiece. includes a second light projecting section which, and a light emitting end face of the workpiece that be irradiated with light to emit light,
An imaging unit that images a plurality of different light emitting portions generated on the end face of the workpiece by the light;
A detection unit that detects a position of the workpiece based on a result of imaging by the imaging unit;
A determination unit for determining whether the one slit light intersects the end face of the workpiece at two intersections;
A moving unit that moves the first light projecting unit so that the one slit light intersects the end surface of the workpiece at two intersections based on the determination result of the determining unit ;
The imaging unit images a plurality of bright spots generated at a plurality of locations on the end surface of the workpiece by the slit light ,
The workpiece has a curved end surface capable of forming a plurality of intersections with respect to one slit light irradiated from one light projecting unit,
The detection unit is generated by the other slit light generated at the two intersections where the one slit light and the end face of the workpiece intersect, the bright point generated at the two intersections, and the other spot. A workpiece position detection system that detects the position of the workpiece based on imaging results of a plurality of bright spots including bright spots . Furthermore, it has an ultrasonic measurement unit that measures the distance to the workpiece using ultrasonic waves,
The workpiece according to any one of claims 1 to 8 , further comprising a comparison unit that compares the workpiece position detected by the detection unit and the distance measured by the ultrasonic measurement unit. Position detection system. At least one light projecting unit that emits light so that the end surface of the work that is a transparent body emits light;
An imaging unit that images a plurality of different light emitting portions generated on the end face of the workpiece by the light;
A detection unit that detects a position of the workpiece based on an imaging result by the imaging unit,
The light projecting unit refers irradiation so as to cross the slit light to an end face of the workpiece,
The imaging unit images a plurality of bright spots generated at a plurality of locations on the end surface of the workpiece by the slit light ,
The workpiece is stored in a pallet in a stacked state at a predetermined interval,
The detection unit detects the position of the workpiece based on an imaging result captured by the imaging unit while being stored in the pallet;
The pallet is a pallet for transportation used for transportation of workpieces,
The detection unit is characterized in that the coordinate system in the pallet is a reference coordinate system, and a relative positional relationship between the reference coordinate system and the coordinate system of the workpiece is obtained from the plurality of bright spots . Furthermore, workpiece position detection system of claim 1 0, characterized in that it comprises a correcting unit for correcting on the basis of teaching data of the robot for supporting the workpiece to the positional relationship. The workpiece is the workpiece position detecting system according to any one of claims 1 to 1 1, wherein it is glass. The workpiece is the workpiece position detection system of claim 1 2, characterized in that a window glass for vehicles.