JP2006302019A - Robot controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot controller realizing automatic teaching with one camera. <P>SOLUTION: The robot controller which controls a cartesian coordinate robot movable along three orthogonal axes (X, Y, and Z axes) includes an imaging means for imaging an operation face pressed by the robot, a radiation means which is moved on an XY plane parallel with the operation face together with the robot and radiates a pointer to an intersection between an extension in the Z direction of the robot and the operation face, and a pressure detection means for detecting a pressure of the robot to the operation face. A vector which converts a vector of xy-direction movement of the robot to a pointer movement vector on an imaged image is calculated, and a pointer movement vector to a desired point designated by an operator, on the imaged image is converted to a vector of xy-direction movement to move the robot, and it is determined whether the pointer is placed within a prescribed range from the desired point on the imaged image or not. In the case that it is determined that the pointer is not placed there, correction is performed, and the XY plane position and the robot are moved in the Z direction, and a position in the Z direction at the time when the detected pressure exceeds a prescribed point is stored in association with the desired point. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention generally relates to a robot control apparatus that controls a Cartesian coordinate robot, and more particularly to a robot control apparatus that realizes automatic teaching with a single camera.

  2. Description of the Related Art Conventionally, a robot controller that controls an orthogonal coordinate robot that can move along three orthogonal axes (X, Y, and Z axes) is known.

  In addition, the three-dimensional coordinates of the robot are usually obtained from two two-dimensional images captured using two cameras (see, for example, Patent Document 1).

  FIG. 1 shows an example of a Cartesian coordinate robot that automatically operates a push button type switch for inspection purposes and its control device. Here, it is assumed that the horizontal direction in FIG. 1 is the X axis, the vertical direction is the Y axis, and the vertical direction is the Z axis, and the switch on the switch surface P arranged along the X axis is pushed by the robot.

  In the example of FIG. 1, the Cartesian coordinate robot 101 controlled by the robot control device 100 is carried by a frame 102 provided along the X axis, and is movable on an X-direction trajectory provided on the frame 102. One carriage 103, a second carriage 104 carried by the first carriage 103 and movable on a Y-direction trajectory provided on the first carriage 103, and a Z-axis on the second carriage 104 The operation arm 105 is provided in parallel and can be expanded and contracted along the Z-axis.

  With such a configuration, the tip of the operation arm 105 can take arbitrary three-dimensional coordinates within a predetermined operating range.

  In the example of FIG. 1, the three-dimensional position of the tip of the operation arm 105 is detected using two cameras 106 and 107. The camera 106 is a camera that images the XY plane, and images the position of the tip of the operation arm 105 on the XY plane. The camera 107 is a camera that images the YZ plane, and images the position of the tip of the operation arm 105 on the YZ plane, particularly the depth in the Z-axis direction.

  Images captured by the two cameras 106 and 107 are displayed on the display by the image processing PC 108. When teaching (teaching) the three-dimensional coordinates for the switch operation, the operator looks at two two-dimensional images displayed on the display and is suitable for operating the switch having the tip of the operation arm 105. The coordinates are stored in the robot controller 109 when in the three-dimensional position.

  When requested by the operator to operate a certain switch, the robot controller 109 moves the robot 101 to a three-dimensional position taught in advance for the switch.

As described above, according to the conventional Cartesian coordinate robot and its control device, the three-dimensional position of the robot is usually detected by two cameras, and the desired operation position is usually set manually by the operator. Conceivable.
Japanese Utility Model Publication No. 6-47670

  However, the conventional method as described above is difficult to use in a narrow space, for example, when a switch provided on an instrument panel is inspected in a passenger compartment of a completed vehicle.

  When the vehicle instrument panel switch is operated with the structure and method illustrated in FIG. 1, the camera 106 that images the XY plane is not obstructed by an obstacle such as a steering handle or a seat headrest and the robot itself. Difficult to install.

  Further, it is difficult to install the camera 107 that captures the YZ plane (depth) because the A pillar or the door is an obstacle.

  In order to avoid such obstacles and the robot itself, if two different cameras are installed so that the instrument panel P is imaged from an oblique direction, the two captured images are combined to obtain a three-dimensional coordinate. Becomes complicated.

  Further, in the conventional method as described above, in order to teach each of the operation target buttons, the operator moves the robot, and the operation arm is positioned at an appropriate three-dimensional coordinate for pressing each button. It is necessary to perform a series of manual procedures for confirming on the display and setting the coordinates, which requires a lot of man-hours and a lot of time.

  The present invention is intended to solve such problems, and a main object of the present invention is to provide a robot control device that realizes automatic teaching with a single camera.

One aspect of the present invention for achieving the above object is a robot control apparatus for controlling a Cartesian coordinate robot movable along three orthogonal axes (X, Y, Z axes),
Imaging means for imaging an operation surface pressed by the robot;
An irradiating means for moving together with the robot on an XY plane parallel to the operation surface and irradiating a pointer to the intersection of the Z-direction extension line of the robot and the operation surface;
Pressure detecting means provided on a surface facing the operation surface of the robot and detecting a pressure with which the robot presses the operation surface;
Calculating a conversion vector for converting a movement vector on the XY plane of the robot into a movement vector of the pointer on the image captured by the imaging unit;
Movement of the robot on the XY plane by using the conversion vector as a movement vector from the current position of the pointer on the image picked up by the image pickup means to a desired point on the operation surface designated by the operator Converted into a vector, and moves the robot on the XY plane according to the obtained movement vector,
After the movement, it is determined whether or not the pointer is located within a predetermined range from the desired point on the image picked up by the image pickup means, and if not, the position of the robot on the XY plane is corrected. The robot position on the XY plane is stored in association with the desired point,
After determining the XY direction position, the robot is moved in the Z direction, and the Z direction position when the pressure detected by the pressure detecting means exceeds a predetermined threshold value is stored in association with the desired point. It is a robot control device.

  In this aspect, the robot is a robot for autonomously inspecting the function of the push button switch, for example, and the operation surface is, for example, a panel surface on which the push button switch to be inspected is arranged. (For example, an instrument panel of a car).

  Moreover, in this one aspect | mode, it is preferable that an imaging means is installed diagonally with respect to an operation surface so that it may not be interrupted | blocked by the robot.

  According to this aspect, the three-dimensional position for pressing an appropriate pressure on the point specified on the two-dimensional image captured by the imaging unit, the pressure detection unit, and the calculation of the conversion vector as described above ( Since the robot can automatically detect and store (coordinates), the teaching work for storing the desired three-dimensional coordinates in the robot can be automated using only one imaging means.

  ADVANTAGE OF THE INVENTION According to this invention, the robot control apparatus which implement | achieved automatic teaching with one camera can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The basic concept of the Cartesian coordinate robot and its control device, the main hardware configuration, the operating principle, the basic control method, and the like are known to those skilled in the art and will not be described in detail.

  Further, in the following description of one embodiment, as in the case of FIG. 1 described above, an example of a Cartesian coordinate robot that automatically operates a push button switch for inspection purposes and its control device will be given. In particular, the case of an inspection robot that autonomously presses a button arranged on the instrument panel of a completed vehicle that requires operation in a narrow vehicle interior is given as an example.

  FIG. 2 is a schematic configuration diagram of the Cartesian coordinate robot 201 and its control device 200 according to an embodiment of the present invention. Here, it is assumed that the switch on the instrument panel P is pushed by the robot 201, and the horizontal direction in FIG. 2 is the X axis, the vertical direction is the Y axis, and the vertical direction is the Z axis. That is, the instrument panel P is parallel to the XY plane.

  A Cartesian coordinate robot 201 controlled by the robot controller 200 is supported by a frame 202 provided along the X axis, and is movable on an X-direction trajectory (not shown) provided on the frame 202. Carriage 203, a second carriage 204 carried by the first carriage 203 and movable on a Y-direction track (not shown) provided on the first carriage 103, and the second carriage 204 And an operation arm 205 that is provided in parallel to the Z-axis and can be expanded and contracted along the Z-axis.

  With such a configuration, the tip of the operation arm 205 can take arbitrary three-dimensional coordinates within a predetermined operating range. The frame 202 is fixed to the vehicle to be inspected by, for example, providing attachment members for hooking and fixing the handle 202 provided on the roof portion of the upper part of the doors of the driver seat and the passenger seat at both ends.

  A pressure sensor 206 is provided at the tip of the operation arm 205 so as to face the switch surface P. The pressure sensor 206 detects the pressure when the operation arm 205 is further extended toward the switch surface P and pressed after the operation arm 205 contacts the switch surface P.

  On the second carriage 204, a laser pointer device 207 for irradiating a laser pointer in a predetermined direction is provided. Since this laser pointer device 207 is provided on the second carriage 204, it moves on the XY plane together with the first carriage 203 and the second carriage 204, but does not move in the Z-axis direction. Further, the irradiation direction of the laser pointer device 207 is set and fixed so that the laser pointer is irradiated to the point where the Z-axis direction extension line of the operation arm 205 intersects the instrument panel P.

  The robot control device 200 further includes a camera 208 that is fixedly installed at a predetermined angle on the frame 202 and that can image at least an area of the instrument panel P that can be pressed by the operation arm 205. The camera 208 is installed so as to image the instrument panel P from an oblique direction as shown in the figure so as not to be blocked by the steering handle or the robot 201 itself. In order to avoid obstacles, an angle in the elevation direction may be provided.

  Therefore, the camera 208 can take an image of the switches on the instrument panel P and the laser pointer on the instrument panel P irradiated by the laser pointer device 207.

  An image captured by the camera 208 is displayed on a display (not shown) by the image processing PC 209. In addition, the operator can move the robot 201 to desired XYZ coordinates through the robot controller 210.

  Next, the flow of automatic teaching processing using the robot control device 200 having such a configuration will be described with reference to FIGS.

  FIG. 3 is a flowchart showing a schematic flow of automatic teaching and automatic inspection using the robot controller 200.

  First, the operator fixes the frame 202 to the vehicle to be inspected and performs installation work so that the robot 201 can move in the vehicle interior (S301).

  When the robot is set up so as to be operable, first, a process for obtaining a conversion vector for converting the movement vector of the robot 201 on the XY plane into a movement vector on the imaging screen imaged by the camera 208 is performed (S302). ).

  First, the image processing PC 209 records the current position of the pointer (for example, the initial position) on the imaging screen captured by the camera 208.

  Next, the robot controller 210 moves the robot 201 by a predetermined movement vector on the XY plane by moving the first carriage 203 and the second carriage 204 by a predetermined amount.

  After the movement, the image processing PC 209 records the pointer position on the captured image after the movement of the robot 201.

  An example is shown in FIG. FIG. 4 shows an example of an image captured by the camera 208. Point A is the pointer position before movement, and point B is the pointer position after the robot 201 is moved by a predetermined XY plane vector.

The image processing PC 209 calculates a pointer movement vector V _D on the captured image. Since the camera 208 is taking an image with respect to the instrument panel P and the illustration is omitted in FIG. 2, the actual vehicle instrument panel has irregularities and inclinations provided in the design. The movement vector 201 on the XY plane does not necessarily match the pointer movement vector on the captured image.

Next, the image processing PC 209 obtains a correspondence relationship between the known XY direction movement vector of the robot and the pointer movement vector V _D on the captured image accompanying this movement. That is, a conversion vector for obtaining a pointer movement vector on the captured image is obtained from the movement vector on the XY plane of the robot.

This can be expressed as an expression:
Pointer movement vector on the captured image = conversion vector × robot movement vector.

  When the conversion vector is calculated as part of the initial setting in this way, the process then proceeds to teaching the robot three-dimensional position for pressing each switch to be inspected (S303).

  An example of the captured image is shown in FIG. Now, it is assumed that the pointer is irradiated to the initial position S, and the operator first teaches the robot three-dimensional coordinates for pressing the switch α among the switches α, β, and γ.

  For this purpose, the operator designates the position of the switch α on the captured image as a teaching position by using a user input device (not shown) such as a mouse or a touch panel connected to the image processing PC 209 (see FIG. 5 x).

Next, the image processing PC 209 obtains a movement vector V _D from the position S on the captured image to the designated position (×). Then, the movement vector on the captured image is converted into a movement vector on the XY plane of the robot using the previously obtained conversion vector, and sent to the robot controller 210.

  When the robot controller 201 receives the movement vector of the robot on the XY plane, the robot controller 201 moves the first carriage 203 and the second carriage 204 so that the movement according to the movement vector is realized.

  When the movement is completed, the image processing PC 209 determines whether or not the pointer matches the point (×) designated by the user on the captured image. Considering the size of the tip of the operation arm 205 and the area of the switch, some deviation is allowed.

  If it is determined that the user-specified switch cannot be pressed even if the operation therm 205 is extended in the instrument panel P direction as it is, the image processing PC 209 determines that the robot 201 of the robot controller 210 Request correction of XY position. The robot controller 210 preferably learns the requested correction amount and correction direction.

  When the match between the pointer and the user designated point is confirmed on the captured image, the XY position is determined as the XY direction position of the robot 201 when the switch is pressed, and is stored in association with the switch position.

  Next, the robot controller 210 extends the operation arm 205 in the instrument panel P direction while monitoring the output of the pressure sensor 207. When the detected pressure exceeds a predetermined threshold, the robot controller 210 determines that the same pressure as when a human lightly pressed the switch is realized, and determines the Z-axis direction position at that time using the switch. It is determined as the Z-direction position at the time of pressing, and is stored in association with the switch position.

  In this way, the operator simply designates the switch position (two-dimensional position at this time) to be taught on the display of the image processing PC 209, and the three-dimensional coordinates for automatically pressing the switch are specified by the robot controller 210. Can be remembered.

  Therefore, thereafter, in order to push the switch for inspection, only the switch position is designated, and the robot 201 automatically moves to the three-dimensional coordinates for pushing the switch (S304).

  Thus, according to the present embodiment, automatic teaching can be realized with one camera. With automatic teaching, the operator can acquire the three-dimensional coordinates for the robot to autonomously press the switch just by specifying the two-dimensional coordinates of the switch to be pressed on the captured image. The labor is greatly reduced and the processing time required for teaching is greatly reduced. In addition, automation improves reproducibility.

  The present invention can be used in a control device for a Cartesian coordinate robot that autonomously presses an object for inspection purposes or the like. The object may be any object such as a push button switch, and its function and size are not limited.

It is a schematic block diagram which shows an example of the control apparatus using the conventional rectangular coordinate robot and two cameras. 1 is a schematic configuration diagram of an orthogonal coordinate robot control device according to an embodiment of the present invention. It is a flowchart which shows the general | schematic flow of the automatic teaching and the automatic test | inspection using the rectangular coordinate robot control apparatus based on one Example of this invention. It is a figure which shows the pointer movement vector on a captured image. It is a figure which shows the movement vector on the captured image to a desired point.

Explanation of symbols

DESCRIPTION OF SYMBOLS 200 Robot control apparatus 201 Robot 202 X-axis frame 203 X direction carriage 204 Y direction carriage 205 Operation arm 206 Pressure sensor 207 Laser pointer 208 Camera 209 Image processing PC
210 Robot controller

Claims (1)

A robot control device that controls a Cartesian coordinate robot movable along three orthogonal axes (X, Y, and Z axes),
Imaging means for imaging an operation surface pressed by the robot;
An irradiation unit that moves together with the robot on an XY plane parallel to the operation surface, and irradiates a pointer to an intersection between the Z-direction extension line of the robot and the operation surface;
Pressure detecting means provided on a surface facing the operation surface of the robot and detecting a pressure with which the robot presses the operation surface;
Calculating a conversion vector for converting a movement vector on the XY plane of the robot into a movement vector of the pointer on the image captured by the imaging unit;
Movement of the robot on the XY plane by using the transformation vector as a movement vector from the current position of the pointer on the image picked up by the image pickup means to a desired point on the operation surface designated by the operator Converted into a vector, and moves the robot on the XY plane according to the obtained movement vector,
After the movement, it is determined whether or not the pointer is located within a predetermined range from the desired point on the image picked up by the image pickup means, and if not, the position of the robot on the XY plane is corrected. And storing the robot position on the XY plane in association with the desired point,
After determining the XY direction position, the robot is moved in the Z direction, and the Z direction position when the pressure detected by the pressure detection means exceeds a predetermined threshold is stored in association with the desired point. Robot control device.

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