JP4862765B2 - Surface inspection apparatus and surface inspection method - Google Patents

Description

  The present invention relates to a surface inspection apparatus that inspects minute defects on a surface by irradiating light onto a three-dimensional curved surface to be inspected, imaging the reflected light, and processing an imaging signal. The present invention relates to an apparatus and method for accurately associating the position of a surface to be inspected with the image taken.

  2. Description of the Related Art Conventionally, for example, in a body painting process in an automobile manufacturing process, a coating defect inspection is performed to check whether or not a predetermined painting has been performed after a painting process. In order to improve the inspection accuracy and work efficiency in this coating defect inspection, there is a surface inspection apparatus capable of detecting defects such as fine scratches and foreign matter adhesion on a glossy surface having a uniform three-dimensional curved surface by imaging signal processing. It is used.

  As a first conventional surface inspection apparatus, as shown in FIG. 7 (A), a plurality of lights 101 and a CCD camera 102 are installed in a tunnel shape along the cross section of the body, and the body passes through the conveyor by a conveyor. An apparatus 100 for inspecting a painted surface is known. As an example of such a surface inspection apparatus, there is a surface inspection apparatus disclosed in Patent Document 1. This is because the surface light source device irradiates the surface to be inspected with parallel light, images the reflected light with a plurality of CCD cameras arranged in a tunnel, and determines whether the image signal level reaches a reference value. By detecting it, a minute defect on the surface is detected.

  In such a surface inspection apparatus, the CCD camera can be made movable. Patent Document 2 discloses a second conventional surface inspection apparatus in which a fluorescent lamp that emits a band-shaped detection light and a CCD camera that captures an image of an illuminated area are attached to a robot hand and scanned on the surface of a vehicle body. Is disclosed.

Furthermore, as shown in FIG. 8 (A), a third conventional technique is used in which a plurality of robots (one in the figure) equipped with an illumination and a camera are installed, and each of these is independently moved on the body for imaging. There is also a coating surface inspection device. In Patent Documents 3 to 5, a surface light source that irradiates light on a coating surface to be inspected, a CCD camera that makes regular reflection light incident on the coating surface to be inspected, and an imaging signal that detects a level change of the image signal There has been disclosed a coating surface inspection apparatus in which an imaging signal processing device for inspecting the presence or absence of a coating surface defect by processing is installed in a robot and the coating surface can be inspected finely according to the imaging characteristics of a CCD camera.
JP 2000-193601 A JP 2005-265522 A JP 2006-242814 A JP 2006-038550 A JP 2003-270162 A

  In the first conventional surface inspection apparatus 100, as shown in FIG. 7B, one line 110 corresponding to the viewing angle is inspected for each CCD camera, and the image signal is processed. The position of the body 103 is calculated by reading the pulse of the conveyor 104, and the calculated position data is associated with the imaging signal processing result. Nowadays, the body of an automobile is becoming a complicated shape, and there are those having uneven parts and curved surfaces with complicated and delicate curves. In such a surface inspection apparatus 100, the CCD camera 102 itself is fixed, It is not suitable for accurately inspecting a three-dimensional body. This is because, when a CCD camera of the first conventional surface inspection apparatus is to be scanned with respect to a complicated workpiece, adjacent imaging regions cannot be overlapped to the extent that they can be inspected, or defects to be detected are imaged. This is because even if it is within the field of view, it may not be recognized as a detectable image. Furthermore, since the relative positional relationship between the camera and the illumination changes, there is a problem that it is difficult to keep the accuracy of the surface inspection constant.

  On the other hand, in the case of the second conventional surface inspection apparatus, first, the computer reads the pulse from the conveyor, calculates the position information of the conveyor, reads the position captured by the CCD camera at the same time as the position information, and then It is necessary to collate the position information of the conveyor and the position information of the camera by the information processing means. Thus, in order to associate the imaging signal processing result with the position information, a certain calculation process is required and time is required.

  In the third conventional surface inspection apparatus 300, as shown in FIG. 8A, a robot 303 having a camera 301 and an illumination 302 moves the camera 301 and the illumination 302 along the surface of the body 304, and at an imaging point. The imaging is performed, the imaging signal is output as a pulse signal, and the coordinate data (X, Y) of the imaging point is output. Subsequently, as illustrated in FIG. 8B, the management terminal 305 determines the position on the body where the imaging signal is captured from the output coordinate data. The surface inspection apparatus 300 can accurately inspect a three-dimensional body. However, since the coordinate information has a large amount of data, it takes time to transmit and receive the coordinate information, and it is actually necessary to set the linear velocity of the robot to a low speed of, for example, about 100 millimeters per second. In order to complete the inspection of the horizontal and vertical surfaces of a single body using such a surface inspection apparatus within a fixed tact of, for example, about one minute, many robots are required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a surface inspection apparatus and an inspection method capable of reducing the time required for inspection without increasing the number of robots.

In order to achieve the above object, a surface inspection apparatus for a vehicle body according to the present invention includes an illumination unit that irradiates the vehicle body with illumination light and an imaging unit that captures an imaging point on the vehicle body and obtains an imaging signal. In addition, a robot arm having a plurality of joints, a robot arm inspection route and a plurality of imaging points are set in advance , and the robot arm is moved along the inspection route, and images are sequentially captured by the imaging means at the plurality of imaging points. An image processing unit, an information storage unit storing coordinate data on the vehicle body at a plurality of imaging points set in advance in the operation processing unit, and order data in which imaging is performed, and an imaging unit sequentially transmitting the data. that against the reference value image signals for each imaging point, a detection unit for determining the presence or absence of defects in each imaging point sequence information rated to the imaging signal is transmitted from the detecting unit Against the order data stored in the part, the association processing unit associates the transmitted image signal and the coordinate data from the detector, the position of the defect in the vehicle body from the coordinate data associated with the image signal in association processor And an inspection result output unit that outputs an inspection result specifying the above .

The motion processing unit preferably sets and stores an inspection route while moving the robot arm, and sets and stores a plurality of imaging points while moving the robot arm along the inspection route.
The detection unit classifies each image signal in reference to the reference value and classifies it into a plurality of stages, and the inspection result output unit outputs an inspection result indicating the size of the defect in a plurality of stages by each image signal classified in a plurality of stages. It is good to do .

Preferably, the surface inspection apparatus includes a plurality of robot arms, and each robot arm has a corresponding detection unit.

According to the vehicle body surface inspection method of the present invention, an imaging unit is provided at the tip of a robot arm having a plurality of joints, and a detection unit exists on the surface to be inspected of the vehicle body based on an imaging signal obtained by the imaging unit. It detects the defect, and the teaching step of storing in advance setting a plurality of image pickup point and test route while moving the robot arm to the operation processing unit connected to the robot arm, a plurality of imaging point set in advance The coordinate data on the body in the learning step for transmitting to the data processing unit in the order in which the imaging is performed, storing the coordinate data and the order data in which the imaging is performed in the information storage unit of the data processing unit, and the robot arm inspecting while operating along the route, imaged sequentially imaging means at each imaging point sends to the data processing unit an imaging signal obtained in turn, feed Is an imaging signal of the imaging point was to determine the presence or absence of defects in each imaging point against the reference value, against an order and the order data that the image signal is transmitted from the detecting unit, transmitted from the detection unit An inspection step for associating the imaging signal with the coordinate data, and an output step for outputting an inspection result specifying the position of the defect in the vehicle body from the coordinate data associated with the imaging signal.

  According to the surface inspection apparatus of the present invention, when the motion processing unit moves the robot arm along a preset inspection route and causes the imaging unit to capture images at a plurality of preset imaging points, the association processing unit Since the image data and the coordinate data of the imaging point can be associated with the order data stored in the information storage unit as the key, the coordinate data of the imaging point need not be output from the robot arm during the actual surface inspection. The operating speed of the arm can be improved.

  According to the surface inspection method of the present invention, in the inspection step, the robot arm operates along the set inspection route, and the image pickup means picks up images at a plurality of preset image pickup points and sends the image pickup signal to the data processing unit. Since the data processing unit can associate the imaging signal and the coordinate data of the imaging point using the order in which the data processing is performed as a key, it is not necessary to output the coordinate data from the robot arm, improving the robot arm's operating speed Can be made.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 and 2 show a surface inspection apparatus according to an embodiment of the present invention. FIG. 2 shows one robot arm, and the other robot arms are not shown.

The surface inspection apparatus 1 includes an inspection unit 2, an inspection result output unit 3, and a data processing unit 4. The data processing unit 4 includes an association processing unit 4a and a coordinate information storage unit 4b.
The inspection unit 2 includes two horizontal surface inspection robots 23 and two vertical surface inspection robots 24 each having a robot arm, and an operation processing unit 25 and an imaging signal processing unit 26 connected to the robots 23 and 24, respectively. The imaging signal processing unit 26 is connected to the association processing unit 4, and the operation processing unit 25 is connected to the coordinate information storage unit 4b.

  The imaging signal processing unit 26 includes a determination table 26a and a determination unit 26b. The operation processing unit 25 includes a teaching unit 25a and a drive processing unit 25b. The inspection result output unit 3 includes an inspection result display terminal 31 and a printer 32 connected to the inspection result display terminal 31. The inspection result display terminal 31 includes an output processing unit 31a and a body format storage unit 31b, and the output processing unit 31a is connected to the association processing unit 4a.

  The horizontal surface inspection robot 23 and the vertical surface inspection robot 24 include a plurality of joints and a drive mechanism that drives the joints, and an illumination unit 21 that irradiates the inspection surface of the object to be inspected and an inspection surface at the tip thereof. And a CCD camera 22 which is an imaging means for imaging. The CCD camera 22 is connected to the imaging signal processing unit 26.

Next, a method for performing surface inspection of an automobile using the surface inspection apparatus 1 according to such an embodiment will be described with reference to FIG. 3 for the preparation stage and the flowchart of FIG. 4 for the actual inspection stage.
First, as a preparatory work, a teaching step (step s1) is executed in which the operation processing unit 25 connected to the robots 23 and 24 stores the inspection route and a plurality of imaging points. A known method can be used as the teaching method. For example, there is a method in which the operator operates the robots 23 and 24 using the operation panel of the control operation panel and stores the scanning path. In this method, an operator drives a motor for driving a robot via a robot controller, and a robot arm along imaging points P1 to P4 on a hood and a roof constituting the vehicle body 11 as shown in FIG. This is done by moving the tip. Arrows attached to the scanning paths P1 to P4 indicate the moving direction (scanning direction) of the tips of the robots 23 and 24.

In such a teaching program, a plurality of imaging points are registered, and at each imaging point, the CCD camera 22 provided at the tip of the robots 23 and 24 detects the reflected light from the illumination means 21 at the imaging point, and the detected optics. Information is output as a pulse signal. As a result of teaching, the inspection route and the plurality of imaging points are stored as an operation program in the teaching unit 25b of the operation processing unit 25 connected to the robot.
In teaching, an inspection route and a plurality of imaging points may be created by a so-called offline teaching method in which teaching is performed on a three-dimensional CAD using a solid model or the like without operating the actual robots 23 and 24. .

  Next, a learning step (step s2) is executed. This step is performed by executing the previous operation program for the robots 23 and 24 while the body is stopped, and transmitting the coordinate data on the body at each imaging point to the coordinate information storage unit 4b for storage. Specifically, by sending a command from the teaching unit 25a to the drive processing unit 25b, the robot arms 23 and 24 are operated according to the above-described inspection route (step s21), and the operation processing unit 25 at the registered imaging point. The coordinate data on the body at the imaging point is transmitted to the coordinate information storage unit 4b of the data processing unit 4 (step s22). The coordinate information storage unit 4b stores each coordinate data and the number of times that the coordinate value corresponds to the number of pulse signal transmissions, that is, the data of the order in which imaging is performed as a database 41 as shown in FIG. s23). A part of this database is created for each robot.

Next, the inspection step (step s3) performed at the time of actual surface inspection will be described with reference to the flowchart of FIG.
First, the motion processing unit 25 executes the previous motion program (step s31). Then, as shown in FIG. 5A, the robot arms 23 and 24 operate so that the CCD camera 22 passes through the imaging points P1, P2, P3, and P4 on the body. At that time, the CCD camera 22 detects the reflected light from the illumination means 21 at the imaging points P1, P2, P3, and P4, converts the obtained optical information into a pulse signal, and outputs it (step s32).

  This pulse signal is transmitted to the imaging signal processing unit 26. In the imaging signal processing unit 26, the determination unit 26b determines the presence or absence of a defect on the body at the imaging point by comparing the pulse signal with the determination table 26a. That is, the pulse signal level is classified into, for example, four levels in light of the reference value of the determination table 26a (step s33).

  The information thus obtained is transmitted to the association processing unit 4a of the data processing unit 4 as an imaging signal. The association processing unit 4a associates the imaging signal with the coordinate data by comparing the order of transmission of the imaging signal with the order data stored in the coordinate information storage unit 4b (step s34), and transmits it to the inspection result display terminal 31. (Step s35). Thus, this embodiment differs from the conventional inspection method in that the robot arms 23 and 24 do not output coordinate data at the imaging point. That is, it is possible to perform a quick inspection by omitting the time required to output the coordinate data.

  Next, an output step (step s4) is performed by the inspection result display terminal 31. First, the output processing unit 31a of the inspection result display terminal 31 compares the coordinate data with the body format stored in the body format storage unit 31b, and the imaging point where the imaging signal is obtained corresponds to which position on the body. Mapping that identifies this. That is, the output processing unit 31a extracts data having a defect on the body surface (step s41), and calculates the coordinates where the defect exists from the coordinate data associated with the image data (step s42). Subsequently, as shown in FIG. 1, the size of the defect is shown in three stages at the portion corresponding to the imaging point where the imaging data indicating the existence of the defect is obtained on the inspection book 34 representing each part of the body. A mark of any of Δ, Δ, and X is drawn (step s43). Note that nothing is drawn for an imaging point where there is no defect. The inspection book 34 is displayed on the display of the inspection result display terminal 31 and printed by the printer 32 (step s44).

  If surface inspection is performed using the surface inspection apparatus 2 of the present embodiment, surface inspection can be performed while operating the robot at a high speed of, for example, a linear speed of 350 mm / s, so that the tact time can be increased without increasing the number of robots. Surface inspection can be performed within. Further, it is not necessary to stop the robot for each point, and surface inspection can be performed with a certain accuracy while avoiding unstable movement with acceleration / deceleration.

As described above, the surface inspection apparatus and the surface inspection method of the present invention compare the order in which the imaging signals are transmitted with the order data and associate the imaging signals with the coordinate data, thereby performing the robot arm or operation processing at the imaging point. The unit realizes the surface inspection without outputting coordinate values, and can be implemented in various forms without departing from the gist thereof.
For example, the process for determining the presence or absence of a defect from a pulse signal may be performed by any of the imaging signal processing unit, the data processing unit, and the output processing unit, and the imaging signal processing unit, the data processing unit, and the output processing unit are one. It may be built in the terminal. Further, the horizontal plane inspection robot, the vertical plane inspection robot, and the imaging signal processing units connected to the cameras of these robots are not limited to the number of embodiments.

It is a figure which shows the surface inspection apparatus of embodiment. It is a block diagram which shows the surface inspection apparatus of FIG. It is a flowchart which shows the preparatory step in the surface inspection method of embodiment. It is a flowchart which shows the actual test | inspection step in the surface test | inspection method of embodiment. It is a figure which shows operation | movement of the surface inspection apparatus in the state of FIG. It is a figure which shows the database of coordinate data and the data of the order in which imaging is performed. It is a figure which shows a 1st conventional surface inspection apparatus. It is a figure which shows the 3rd conventional surface inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface inspection apparatus 2 Inspection part 3 Inspection result output part 4 Data processing part 4a Association processing part 4b Coordinate information storage part 22 CCD camera 23 Horizontal surface inspection robot 24 Vertical surface inspection robot 25 Operation processing part 25a Teaching part 25b Drive processing part 26 Imaging Signal processing unit 26a Determination table 26b Determination unit 31 Inspection result display terminal 32 Printer 41 Databases P1 to P4 Imaging points

Claims (5)

A robot arm with a Rutotomoni multiple joints provided on the tip and imaging means for obtaining an image pickup signal by imaging an imaging point on the illumination means and said vehicle body for irradiating illumination light to the vehicle body,
Inspection route of the robot arm and a plurality of the imaging point is set in advance, and the operation processing unit for imaging in said imaging means in turn the plurality of imaging points while moving the robot arm along the test route,
An information storage unit and the order data is stored for each coordinate data and imaging of a preset plurality of imaging points to the operation processing unit is carried out,
A detection unit that determines the presence or absence of a defect at each imaging point by comparing the imaging signal of each imaging point sequentially transmitted from the imaging unit with a reference value;
An association processing unit that compares the order in which the imaging signals are transmitted from the detection unit with the order data stored in the information storage unit , and associates the imaging signals transmitted from the detection unit with the coordinate data ;
A vehicle body surface inspection device comprising: an inspection result output unit that outputs an inspection result specifying a position of a defect in the vehicle body from the coordinate data associated with the imaging signal by the association processing unit . The operation processing unit sets and stores the inspection route while moving the robot arm, and sets and stores the plurality of imaging points while moving the robot arm along the inspection route. Item 1. The vehicle body surface inspection apparatus according to Item 1. The detection unit classifies each imaging signal in a plurality of stages in light of a reference value, and the inspection result output unit determines the size of the defect in a plurality of stages by each imaging signal classified in a plurality of stages. The vehicle body surface inspection apparatus according to claim 1, wherein the inspection result is output. The vehicle body surface inspection apparatus according to any one of claims 1 to 3 , further comprising a plurality of the robot arms and the detection units corresponding to the robot arms. Image pickup means provided at the distal end of a robot arm having a plurality of joints, the detection unit based on imaging signals obtained by the imaging means on the vehicle body surface inspection method for detecting defects present on the imaging point on the vehicle body There,
While moving the robot arm, the teaching steps of storing a plurality of image pickup point and the inspection route set in advance to the operation processing unit connected to the robot arm,
Storing coordinate data of a predetermined plurality of imaging points, and transmitted to the data processing unit in the order in which the imaging is performed, and the order data in the information storage unit of the data processing unit to which the coordinate data and the imaging is performed Learning steps,
While the robot arm is operated along the test route, the imaging means takes an image sequentially in each imaging point the imaging signal obtained is transmitted to the data processing unit in order, of each imaging point sent The imaging signal is compared with a reference value, the presence or absence of a defect at each imaging point is determined by the detection unit, the order in which the imaging signals are transmitted is compared with the order data, and the imaging signal transmitted from the detection unit An inspection step for associating the coordinate data with the coordinate data;
A vehicle body surface inspection method comprising: an output step of outputting an inspection result specifying a position of a defect in the vehicle body from the coordinate data associated with an imaging signal .

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