JP2012061558A - Robot monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a failure of an image recording unit even in a robot monitoring system including only one image recording unit.SOLUTION: The robot monitoring system includes: a robot 10 including an arm 11; a robot controller 20 for calculating first coordinates being the coordinates of the arm 11 and controlling the operation of the arm 11; and a camera device 30 for imaging the robot 10 and its peripheral region to record images thereof. The camera device 30 calculates second coordinates being the coordinates of the arm 11 based on the recorded images, and determines that either of the robot controller 20 and the camera device 30 fails based on the comparison between the first coordinates and the second coordinates.

Description

  The present invention relates to a system for monitoring a robot and its surrounding area.

  2. Description of the Related Art Conventionally, a monitoring system for protecting a robot includes a first image recording unit and a second image recording unit having a common viewing area, and issues a warning signal when a foreign object enters a virtual protected area in the viewing area. Yes (see, for example, Patent Document 1).

Japanese translation of PCT publication 2010-510595

  By the way, generally, when the image recorded by the image recording unit is disturbed, it is difficult to determine whether the image recording unit has failed or whether the object to be recorded in the image has actually changed. .

  Patent Document 1 discloses that two image recording units are simply operated redundantly with respect to each other. With such a configuration, when the images recorded by the two image recording units are different from each other, it is possible to determine that one of the image recording units has failed.

  However, in such a configuration, since two image recording units are required, it is inevitable that the cost of the robot monitoring system increases.

  The present invention has been made in view of such circumstances, and its main purpose is to enable detection of a failure of an image recording unit even in a robot monitoring system including only one image recording unit. It is.

  The present invention employs the following means in order to solve the above problems.

  1st invention calculates the 1st coordinate which is the robot which has an arm, the coordinate of the said arm, and controls the operation | movement of the said arm, and images the said robot and its peripheral region, and records an image Based on the comparison between the first coordinate and the second coordinate, and an image recording unit that calculates the second coordinate that is the coordinate of the arm based on the image recorded by the image recording unit. Determining means for determining that either one of the robot controller or the image recording unit is out of order.

  According to the above configuration, the robot has the arm, and the robot controller calculates the first coordinate which is the coordinate of the arm and controls the operation of the arm. Further, the image recording unit images the robot and its surrounding area and records the image. Then, based on the image recorded by the image recording unit, the second coordinate which is the coordinate of the arm is calculated by the calculating means. That is, the common arm coordinates are calculated by different methods. Note that the robot controller grasps the coordinates of the arm in controlling the operation of the arm, and therefore can use this coordinate as a substitute for the second image recording unit.

  Furthermore, based on the comparison between the first coordinate and the second coordinate, it is determined that one of the robot controller and the image recording unit is out of order. For example, when the first coordinate and the second coordinate are significantly different, it can be determined that either the robot controller or the image recording unit is out of order. Then, whether or not the robot controller is out of order can be determined relatively easily by another method. Therefore, even in a robot monitoring system including only one image recording unit, a failure of the image recording unit can be detected.

  In a second invention, in the first invention, the robot controller repeatedly calculates the first coordinates in a first period, stores the first coordinates in the past, and the image recording unit performs a second period. The robot repeatedly captures the robot and its surrounding area, records the image, and the determination means includes the first coordinate corresponding to the time captured by the image recording unit among the first coordinates in the past, and the imaging It is determined that one of the robot controller and the image recording unit is out of order based on the comparison with the second coordinates calculated by the calculating means based on the image recorded by the above.

  According to the above configuration, the robot controller repeatedly calculates the first coordinates in the first period, and stores the past first coordinates. Further, the image recording unit repeatedly captures the robot and its surrounding area in the second period, and records the image. Then, the second coordinate is calculated by the calculation means based on the recorded image.

  Here, it takes time to perform image processing and the like from imaging by the image recording unit to calculation of the second coordinates by the calculation means. For this reason, when the second coordinate is calculated and compared with the first coordinate calculated at that time, there is a risk of comparing the calculated coordinates with respect to the arms at different times.

  In this regard, according to the above configuration, in the determination by the determination means, the calculation means based on the first coordinates corresponding to the time taken by the image recording unit among the past first coordinates and the image recorded by the image pickup. The calculated second coordinate is compared. Therefore, the first coordinate and the second coordinate corresponding to the time with respect to the arm can be compared, and the accuracy of failure determination can be improved.

  In a third aspect based on the second aspect, the determination means is calculated by the robot controller from the time when the image is recorded by the image recording unit to the time when the second coordinates are calculated by the calculation means. On the basis of a comparison between the first coordinates and the second coordinates calculated by the calculation means based on the image recorded by the imaging, either the robot controller or the image recording unit fails. It is determined that

  The first coordinates calculated by the robot controller before the time when the image is recorded by the image recording unit do not correspond to the second coordinates calculated by the calculating means based on the image recorded by the imaging. On the other hand, the time required from the imaging by the image recording unit to the calculation of the second coordinates by the calculating means is not always constant, and it is not easy to predict the time.

  In this regard, according to the above configuration, the first coordinate calculated by the robot controller is selected from the time when the image is recorded by the image recording unit to the time when the second coordinate is calculated by the calculating means. In addition, the second coordinates calculated by the calculation means are selected based on the image recorded by the image recording unit. Then, the first coordinate and the second coordinate selected in this way are compared. For this reason, the target of the first coordinate to be compared with the second coordinate can be made necessary and sufficient, and the calculation load can be reduced while improving the accuracy of failure determination.

  According to a fourth aspect, in the second or third aspect, the determination unit includes the robot controller from the time when the image is recorded by the image recording unit to the time when the second coordinate is calculated by the calculation unit. When the difference between any one of the first coordinates calculated by the calculation and the second coordinates calculated by the calculation unit based on the image recorded by the imaging is smaller than a determination value, the robot It is determined that the controller and the image recording unit are normal.

  According to the above configuration, when the difference between any one of the first coordinates necessary and sufficient for comparison with the second coordinates and the second coordinates is smaller than the determination value, the robot controller and the It is determined that the image recording unit is normal. As a result, it is possible to appropriately determine that the robot controller and the image recording unit are normal while reducing the calculation load as in the third invention.

  In a fifth invention according to any one of the first to fourth inventions, in the image recorded by the image recording unit, the determination means obtains the first coordinate from the range of the arm including the second coordinate. If it is disconnected, it is determined that either one of the robot controller or the image recording unit is out of order.

  According to the above configuration, in the image recorded by the image recording unit, the range of the arm including the second coordinate is set as the determination range of the first coordinate. When the first coordinate is out of the range, it is determined that either the robot controller or the image recording unit is out of order. For this reason, the determination range of the first coordinate can be easily and appropriately set based on the image recorded by the image recording unit, and the determination process can be performed simply.

  According to a sixth invention, in any one of the first to fifth inventions, the determination means sets an area in the image recorded by the image recording unit that is set larger as the speed of the arm is higher. When the first coordinate is out of the range added around, it is determined that one of the robot controller and the image recording unit is out of order.

  When the robot arm speed is high, it is predicted that the accuracy of calculating the coordinates of the arm will be lower than when the arm speed is low. Therefore, when the determination range of the first coordinate is set uniformly, the accuracy of failure determination may be reduced depending on the speed of the arm.

  In this regard, according to the above configuration, in the image recorded by the image recording unit, a range obtained by adding a region that is set larger as the arm speed is increased around the arm is set as the determination range of the first coordinate. . When the first coordinate is out of the range, it is determined that either the robot controller or the image recording unit is out of order. For this reason, the determination range of the first coordinate can be appropriately set according to the speed of the arm, and it is possible to suppress a decrease in the accuracy of the failure determination.

The schematic diagram which shows the outline | summary of a robot monitoring system. The top view which shows the aspect which monitors a robot and its peripheral region. The flowchart which shows the process sequence of 1st coordinate calculation control. The flowchart which shows the process sequence of 2nd coordinate calculation and failure determination control. The time chart which shows the aspect which compares a 1st coordinate and a 2nd coordinate.

  Hereinafter, an embodiment will be described with reference to the drawings. This embodiment is embodied as a system for monitoring industrial robots that assemble machines and the like in machine assembly factories and the like.

  FIG. 1 is a schematic diagram showing an outline of a robot monitoring system. As shown in the figure, the robot monitoring system includes a robot 10, a robot controller 20, and a camera device 30.

  The robot 10 is a vertical articulated robot and includes an arm 11 having a plurality of joints. At the tip of the arm 11, a hand portion 11a (hand tip) for gripping and releasing the workpiece is provided. Each joint of the robot is provided with a motor, and the arm is driven by the rotation of these motors. Each motor is provided with an electromagnetic brake that brakes its output shaft and an encoder that outputs a pulse signal corresponding to the rotation angle of the output shaft. The robot 10 operates the arm 11 to assemble parts to the workpiece, transport the workpiece, and the like.

  The robot controller 20 includes a CPU, a ROM, a RAM, a data buffer, a drive circuit, a position detection circuit, and the like. These are electrically connected to each other. The ROM stores system programs and operation programs for the robot 10. The RAM stores parameter values and the like when executing these programs. The data buffer temporarily stores information in time series. Detection signals from the encoders are input to the position detection circuit. The position detection circuit detects the rotation angle of the motor provided at each joint based on the detection signal of each encoder.

  Then, the CPU executes an operation program to feedback control the rotation angle of each joint of the robot 10 to the target rotation angle based on the position information input from the position detection circuit. In this embodiment, the CPU calculates the coordinates (first coordinates) of the hand unit 11a and each joint based on the rotation angle of each motor, and sequentially stores the coordinates and the time at that time in a data buffer. . The data buffer stores a plurality of such sets of data.

  The camera device 30 (image recording unit) includes a CCD camera, a signal amplification unit, an A / D conversion unit, a difference image acquisition unit, a moving object detection unit, a determination unit, and the like. The CCD camera is arranged on the ceiling of the building, and images the robot 10 and its peripheral area from above. The signal amplifying unit amplifies the output signal of the CCD camera. The A / D converter converts the amplified video signal into a digital signal. The difference image acquisition unit records the digital signal image at a predetermined time interval, and obtains a difference between the two recorded images. The moving object detection unit detects a moving object by binarizing the difference image with a threshold value. The determination unit calculates the coordinates of a moving object other than the robot 10, and transmits a stop instruction for the robot 10 to the robot controller 20 when the moving object enters a dangerous area near the robot 10.

  FIG. 2 is a plan view showing a mode of monitoring the robot and its surrounding area. As shown in the figure, images of the robot 10 and its surrounding area are acquired in imaging by the CCD camera of the camera device 30. Then, the difference between the images recorded at a predetermined time interval is obtained by the difference image acquisition unit, and the moving object is detected by the moving object detection unit based on the difference image. Here, a dangerous region R is set around the robot 10 based on the length of the arm 11. When the worker M enters the dangerous area R as a moving body other than the robot 10, a stop command for the robot 10 is transmitted from the determination unit to the robot controller 20.

  In the present embodiment, the determination unit (calculation unit) of the camera device 30 also calculates coordinates (second coordinates) for the arm 11 of the robot 10. Then, based on the comparison between the coordinates (first coordinates) of the arm 11 calculated by the robot controller 20 and the second coordinates, the determination unit (determination means) determines whether either the robot controller 20 or the camera device 30 is Determine that there is a failure. Specifically, when the first coordinate and the second coordinate match, or when the difference between the first coordinate and the second coordinate is smaller than the determination value, the robot controller 20 and the camera device 30 are normal. Is determined. On the other hand, if the first coordinate and the second coordinate do not match, or if the difference between the first coordinate and the second coordinate is larger than the determination value, one of the robot controller 20 and the camera device 30 has failed. It is determined that

  FIG. 3 is a flowchart showing a processing procedure of the first coordinate calculation control. This series of processing is repeatedly executed by the robot controller 20 at a predetermined cycle (first cycle).

  First, the rotation angle of the motor provided at each joint of the arm 11 is acquired (S11). Specifically, the position detection circuit detects the rotation angle of the motor provided at each joint based on the detection signal of each encoder.

  Subsequently, the rotation angle of each motor is converted into the same coordinate system as that of the camera device 30, and the coordinates of the hand unit 11a and each joint are calculated (S12). Specifically, the CPU converts the rotation angle of each motor input from the position detection circuit into an orthogonal coordinate system (xy coordinate system) on the horizontal plane, and coordinates of the hand unit 11a and each joint on the xy plane. (First coordinate) is calculated. Specifically, the first coordinates of the hand unit 11a are calculated as (x1, y1), the first coordinates of the first joint as (x2, y2), and the first coordinates of the second joint as (x3, y3). At this time, the origin of the xy coordinate system in the image shown in FIG. 2 is matched with the origin of the xy coordinate system after the conversion.

  Subsequently, the first coordinate of the hand unit 11a and each joint in the xy coordinate system and the time t1 when the first coordinate is calculated are paired and stored in the data buffer (S13). Specifically, data in a format such as (x1, y1, t1), (x2, y2, t1)... Is stored in the data buffer. The first coordinates of the hand unit 11a and each joint calculated at time t2 are (x1, y1, t2) and (x2, y2, t2), respectively. Then, this series of processing is temporarily ended (END).

  FIG. 4 is a flowchart showing a processing procedure of second coordinate calculation and failure determination control. This series of processing is repeatedly executed by the camera device 30 at a predetermined cycle (second cycle). In addition, this 2nd period is longer than the said 1st period, and is specifically about 3 times the 1st period in detail.

  First, the silhouette of the arm 11 of the robot 10 is extracted based on the image recorded by imaging (S21). Specifically, the CCD camera images the robot 10 and its surrounding area, and the difference image acquisition unit obtains a difference between two images recorded at a predetermined time interval. The moving object detection unit binarizes the difference image using a threshold value to detect the silhouette of the arm 11.

  Subsequently, with respect to the detected silhouette of the arm 11, the coordinates of each point constituting the silhouette are calculated (S22). Specifically, the determination unit of the camera device 30 calculates the coordinates (second coordinates) of each point with reference to the same xy coordinate system as that of the robot controller 20. Specifically, the second coordinates of the first point are calculated as (x1, y1), the second coordinates of the second point as (x2, y2), and the second coordinates of the third point as (x3, y3). Then, data in the form of (x1, y1, t1), (x2, y2, t1)... Is created by combining the second coordinates and the time t1 imaged by the CCD camera. These data also include data of each point corresponding to the hand portion 11a of the arm 11 and each joint.

  Subsequently, the first coordinate corresponding to the imaging time t1 is acquired from the data buffer of the robot controller 20 (S23). As described above, the data buffer of the robot controller 20 includes data (x1, y1, t1), (x2, y2, t1), which is a set of the first coordinates of the hand unit 11a and each joint and the calculation time. .., (X1, y1, t2), (x2, y2, t2)..., (X1, y1, t3), (x2, y2, t3). Therefore, the determination unit obtains, from the data buffer, the first coordinates included in the period from the imaging time t1 to the time tn when the second coordinates are calculated as the first coordinates corresponding to the imaging time t1, that is, the first coordinate group. get. Specifically, (x1, y1, t1), (x2, y2, t1) ..., (x1, y1, t2), (x2, y2, t2) ..., (x1, The first coordinates of data such as y1, tn-1), (x2, y2, tn-1)..., (x1, y1, tn), (x2, y2, tn).

  Thereafter, it is determined whether or not the first coordinate at any time in the first coordinate group is included in the silhouette of the arm 11 (S24). Specifically, the determination unit creates the second coordinates of the data corresponding to the imaging time t1, such as (x1, y1, t1), (x2, y2, t1), etc., created as described above, that is, imaging. The second coordinates of each point constituting the silhouette corresponding to time t1 are acquired. Then, in the first coordinates at any time of the first coordinate group, it is determined whether or not the first coordinates of the hand unit 11a and each joint are all included in the second coordinates of each point. That is, it is determined whether the first coordinates of the hand unit 11a and each joint coincide with any of the second coordinates of each point in the first coordinates at any time of the first coordinate group.

  In the above determination, when it is determined that the first coordinate at any time in the first coordinate group is included in the silhouette of the arm 11 (S24: YES), the robot controller 20 and the camera device 30 are normal. This series of processing is once terminated (END). On the other hand, in this determination, when it is determined that the first coordinate at any time of the first coordinate group is not included in the silhouette of the arm 11 (S24: NO), any one of the first coordinate group It is determined whether or not the first coordinate of the time is included in the silhouette of the arm 11 and the vicinity thereof (S25).

  Specifically, the determination unit sets a neighborhood region around the silhouette of the arm 11 according to the speed of the arm 11. This near region is set larger as the speed of the arm 11 is higher. The speed of the arm 11 is input from the robot controller 20 to the camera device 30. In the first coordinates at any time of the first coordinate group, the first coordinates of the hand unit 11a and each joint are all included in the silhouette of the arm 11 and the coordinates of each point in the vicinity area. Determine whether or not. That is, in the first coordinates at any time of the first coordinate group, whether or not the first coordinates of the hand unit 11a and each joint coincide with any of the silhouette of the arm 11 and the coordinates of each point in the vicinity region. To determine.

  In the above determination, when it is determined that the first coordinate at any time in the first coordinate group is included in the silhouette of the arm 11 and the vicinity thereof (S25: YES), the robot controller 20 and the camera The apparatus 30 determines that it is normal, and once ends this series of processes (END). On the other hand, in this determination, if it is determined that the first coordinate at any time of the first coordinate group is not included in the silhouette of the arm 11 and the vicinity region thereof (S25: NO), the robot controller 20 and It is determined that any one of the camera devices 30 has failed, and the robot 10 is stopped (S26). Specifically, the determination unit transmits a stop command for the robot 10 to the robot controller 20. Then, this series of processing is temporarily ended (END).

  FIG. 5 is a time chart showing an aspect in which the first coordinate and the second coordinate are compared.

  As shown in FIG. 5A, the robot controller 20 repeatedly calculates the first coordinates of the hand unit 11a and each joint in the first cycle. Each point C1, C2,... Cn indicates the timing at which the first coordinates are calculated.

  As shown in FIG. 5 (b), in the camera device 30, imaging is performed by the CCD camera repeatedly in the second period. Each point S1, S2,... Sn represents the timing at which the robot 10 and its surrounding area are imaged by the CCD camera. The second period is approximately three times as long as the first period.

  In the camera device 30, after the imaging at the time t <b> 1 by the CCD camera, a period T <b> 11 is required for signal capture and conversion, and a period T <b> 12 is required for acquiring a difference image, detecting a moving object, and calculating a second coordinate. ing. Then, by the time t2 when the second coordinate is calculated in the camera device 30, the first coordinate is calculated at the points C2 and C3 in the robot controller 20.

  Here, comparing the first coordinate at the time closest to time t2 with the second coordinate calculated based on the imaging at time t1, the first coordinate representing the coordinates of the robot 10 at point C3 and the point S1 The second coordinate representing the coordinates of the robot 10 at is compared. Therefore, there is a possibility that the accuracy of determining the failure of the robot controller 20 and the camera device 30 is lowered.

  Therefore, the first coordinates calculated during the period from the imaging time t1 to the time t2 when the second coordinates are calculated, that is, the first coordinates calculated at the points C1, C2, and C3, respectively, are acquired. Then, it is determined whether any of the first coordinates calculated at these points C1, C2, and C3 is included in the silhouette of the arm 11 of the robot 10. That is, the lengths of the periods T11 and T12 change each time, and are different from the lengths of the periods T21 and T22 in the next cycle. However, the first coordinate corresponding to the second coordinate of the robot 10 at the point S1 is included in the first coordinate group calculated in the period from the time t1 to the time t2.

  Then, in the first coordinates at the point C1, when the hand 11a of the arm 11 and the first coordinates of each joint are all included in the silhouette of the arm 11, the robot controller 20 and the camera device 30 are determined to be normal. Is done. On the other hand, in the first coordinates at the point C1, when any one of the hand 11a of the arm 11 and the first coordinates of each joint deviates from the silhouette of the arm 11, the first coordinate at the point C1 is the second coordinate. Is determined not to match. Similarly, the first coordinates at points C2 and C3 are also compared with the second coordinates.

  If it is determined that the first coordinates at the points C2 and C3 also do not match the second coordinates, one of the first coordinates calculated at these points C1, C2, and C3 is the silhouette of the arm 11. And whether it is included in the vicinity region. In this determination, if any of the first coordinates calculated at the points C1, C2, and C3 is included in the silhouette of the arm 11 and the vicinity thereof, the robot controller 20 and the camera device 30 are determined to be normal. Is done. On the other hand, if none of the first coordinates at the points C1, C2, and C3 is included in the silhouette of the arm 11 and the vicinity thereof, either the robot controller 20 or the camera device 30 has failed. Determined. Thereafter, similarly, the first coordinate and the second coordinate are compared for each second period.

  Whether or not the robot controller 20 is out of order can be determined relatively easily using, for example, a teaching pendant (teaching operation device) connected to the robot controller 20 and operating the robot by manual operation. The teaching pendant includes a control unit configured by a microcomputer including a CPU, a RAM, and a ROM, various manual operation keys, a display, and the like. The operator M can manually operate the teaching pendant to create, modify, and register a robot operation program, set various parameters, execute the teaching operation program, and perform jog feed.

  Then, the operator M can determine whether or not the robot controller 20 has failed by diagnosis of the robot controller 20 using the teaching pendant. In this determination, when it is determined that the robot controller has not failed, it is determined that the camera device 30 has failed. When it is determined that the robot controller has failed, the camera device 30 is normal. It can be determined that there is.

  The embodiment described above has the following advantages.

  The robot controller 20 calculates the first coordinates which are the coordinates of the hand portion 11a of the arm 11 and each joint. The camera device 30 captures an image of the robot 10 and its surrounding area and records the image. Then, based on the image recorded by the camera device 30, the determination unit calculates second coordinates that are coordinates of the hand unit 11 a of the arm 11 and each joint. That is, the coordinates of the hand portion 11a of the common arm 11 and the joints are calculated by the control of the robot 10 by the robot controller 20 and the image processing by the camera device 30, respectively. Furthermore, based on the comparison between the first coordinate and the second coordinate, it is determined that one of the robot controller 20 and the camera device 30 is out of order. Then, whether or not the robot controller 20 is out of order can be determined relatively easily by another method. Therefore, even in a robot monitoring system including only one camera device 30, a failure of the camera device 30 can be detected.

  The robot controller 20 repeatedly calculates the first coordinates in the first period, and stores the past first coordinates in the data buffer. In addition, the camera device 30 repeatedly captures the robot 10 and its surrounding area in the second period, and records the image. Then, the determination unit calculates the second coordinates based on the recorded image. Here, in the determination by the determination unit, the first coordinate corresponding to the time when the image was captured by the CCD camera among the first coordinates in the past, and the second coordinate calculated by the determination unit based on the image recorded by the imaging Are compared. Therefore, the first coordinate and the second coordinate corresponding to the time with respect to the arm 11 can be compared, and the accuracy of failure determination can be improved.

  The first coordinate group calculated by the robot controller 20 is selected from the time when the image is captured by the CCD camera to the time when the second coordinate is calculated by the determination unit. In addition, the second coordinates calculated by the determination unit are selected based on the image recorded by the imaging of the camera device 30. Then, the first coordinate group thus selected and the second coordinate are compared. For this reason, the target of the first coordinate to be compared with the second coordinate can be made necessary and sufficient, and the calculation load can be reduced while improving the accuracy of failure determination.

  -Furthermore, when any of the first coordinates (first coordinate group) necessary and sufficient as a target to be compared with the second coordinates is included in the silhouette of the arm 11 or in the vicinity of the silhouette, It is determined that the robot controller 20 and the camera device 30 are normal. As a result, it is possible to appropriately determine that the robot controller 20 and the camera device 30 are normal while reducing the calculation load.

  In the image recorded by the camera device 30, the silhouette of the arm 11 including points corresponding to the hand unit 11a and each joint is set as the determination range of the first coordinate. Then, when the first coordinate is out of the range, it is determined that one of the robot controller 20 and the camera device 30 may be broken, and the following determination is further performed. For this reason, the determination range of the first coordinate can be set easily and appropriately based on the image recorded by the camera device 30, and the determination process can be performed simply.

  In the image recorded by the camera device 30, a range obtained by adding a neighborhood region that is set larger as the speed of the arm 11 is increased around the silhouette is set as the determination range of the first coordinate. Then, when the first coordinate is out of the range, it is determined that one of the robot controller 20 and the camera device 30 is out of order. For this reason, the determination range of the first coordinate can be appropriately set according to the speed of the arm 11, and the deterioration of the accuracy of the failure determination can be suppressed.

  In the configuration in which it is determined that one of the camera devices is broken when the images recorded by the two camera devices are different from each other, when any foreign object such as an insect is imaged by one camera device, It is determined that the camera device is out of order. On the other hand, even if a foreign object such as an insect is imaged by the camera device 30, if the first coordinates are included in the silhouette of the arm 11 or the region near the silhouette, the robot controller 20 and the camera device 30 Determined to be normal. Therefore, it can suppress that a failure is misdetected by foreign materials, such as an insect.

  The above-described embodiment can be modified as follows.

  In the above embodiment, the robot controller 20 detects the rotation angle of the motor provided in each joint based on the detection signal of each encoder. However, the target rotation angle of each motor is determined as the rotation angle of each motor. Can be substituted.

  In the above embodiment, the silhouette of the entire arm 11 of the robot 10 is extracted. However, only the silhouette near the portion corresponding to the hand portion 11a and each joint in the arm 11 may be extracted. In this case, since the number of second coordinates to be compared with the first coordinates can be reduced, the calculation load of the determination unit can be reduced and the processing speed can be improved.

  Also, a motion vector (optical flow) representing the motion of each point in the recorded image is calculated, and the silhouette of the arm 11 is detected only for the moving direction of the arm 11 based on this optical flow. Also good. In this case, the calculation load of the process of extracting the silhouette of the arm 11 can be reduced.

  In the above embodiment, the robot controller 20 and the camera device 30 are determined to be normal when the hand 11a of the arm 11 and the first coordinates of each joint are all included in the silhouette of the arm 11. However, when the hand 11a of the arm 11 and a part of the first coordinates of each joint are included in the silhouette of the arm 11, the robot controller 20 and the camera device 30 can be determined to be normal.

  In the above embodiment, the orthogonal coordinate system is adopted, but other coordinate systems such as an oblique coordinate system and a circular coordinate system can also be adopted.

  In the process shown in FIG. 4, only one of the process of S24 and the process of S25 may be executed.

  In the above embodiment, the first coordinate included in the period from the imaging time t1 to the time tn when the second coordinate is calculated is acquired as the first coordinate corresponding to the imaging time t1, but the time closest to the time t1 Only the first coordinates calculated in the above may be acquired. In this case, since the number of the first coordinates to be compared with the second coordinates can be reduced, the calculation load of the determination unit can be reduced and the processing speed can be improved.

  In the above embodiment, the camera device 30 executes the process of determining the failure of the robot controller 20 and the camera device 30 based on the comparison between the first coordinate and the second coordinate. You can also Also, the robot controller 20 can execute the process of calculating the second coordinates based on the image recorded by the camera device 30.

  In the above embodiment, the CCD camera images the robot 10 and its peripheral area from above, but adopts a configuration in which the robot 10 and its peripheral area are imaged from other directions, such as a configuration that images the robot 10 and its peripheral area from the side. May be.

  The camera device 30 is not limited to the one provided with the CCD image sensor, but may be provided with another type of digital camera such as one provided with a CMOS image sensor.

  The robot 10 is not limited to a vertical articulated robot, and may be any type of robot having an arm.

  DESCRIPTION OF SYMBOLS 10 ... Robot, 11 ... Arm, 20 ... Robot controller, 30 ... Camera apparatus (image recording unit).

Claims (6)

A robot having an arm;
Calculating a first coordinate which is a coordinate of the arm, and a robot controller for controlling the operation of the arm;
An image recording unit that images the robot and its surrounding area and records an image;
Calculating means for calculating a second coordinate which is a coordinate of the arm based on an image recorded by the image recording unit;
Determination means for determining that one of the robot controller and the image recording unit is out of order based on a comparison between the first coordinate and the second coordinate;
A robot monitoring system comprising: The robot controller repeatedly calculates the first coordinates in a first period, stores the first coordinates in the past,
The image recording unit records the image by repeatedly capturing the robot and its surrounding area in a second period,
The determination unit is configured to calculate the first coordinate calculated by the calculation unit based on the first coordinate corresponding to the time when the image was recorded by the image recording unit and the image recorded by the imaging. The robot monitoring system according to claim 1, wherein it is determined that one of the robot controller or the image recording unit is out of order based on a comparison with two coordinates.   The determination unit records the first coordinates calculated by the robot controller from the time when the image is recorded by the image recording unit to the time when the second coordinates are calculated by the calculation unit, and is recorded by the imaging. 3. The robot according to claim 2, wherein one of the robot controller and the image recording unit is determined to be out of order based on a comparison with the second coordinate calculated by the calculation unit based on the image. Monitoring system.   The determination means includes any one of the first coordinates calculated by the robot controller from the time when the image was recorded by the image recording unit to the time when the second coordinates were calculated by the calculation means, The robot controller and the image recording unit are determined to be normal when a difference from the second coordinate calculated by the calculation unit based on the image recorded by imaging is smaller than a determination value. The robot monitoring system according to 2 or 3.   In the image recorded by the image recording unit, the determination means is one of the robot controller and the image recording unit when the first coordinate is out of the range of the arm including the second coordinate. The robot monitoring system according to any one of claims 1 to 4, wherein the robot is determined to be out of order.   In the image recorded by the image recording unit, when the first coordinate deviates from a range in which an area set larger as the speed of the arm is larger is added around the arm in the image recorded by the image recording unit, The robot monitoring system according to claim 1, wherein one of the robot controller and the image recording unit is determined to have failed.

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