JP6457208B2 - Operation instruction system and operation instruction method for robot - Google Patents

Description

  The present invention relates to an operation instruction system and an operation instruction method for instructing a robot to perform an operation.

  In operations such as teaching a robot, it is necessary to instruct the robot to perform an operation such as movement. For example, in the online teaching work which is a kind of teaching work of the robot, the teaching work is performed while instructing the robot to move using a switch or joystick arranged in a lunch box-like device called a teaching pendant.

  However, in the operation instruction to the robot using the conventional teaching pendant, only the movement button along the axis of the preset coordinate system is provided on the teaching pendant, so the direction is different from the axis of the preset coordinate system. Cannot move directly. For this reason, it is necessary for the operator to switch the button many times, and it is necessary to always instruct the operation while paying attention to the direction of the coordinate system that cannot be seen by the eyes, which is complicated.

  As described above, the conventional operation instruction system for the robot has a problem that the work becomes complicated.

  Therefore, the present invention has been made to solve such a problem, and an object thereof is to facilitate an operation instruction to a robot.

  In order to solve the above-described problem, an operation instruction system for a robot according to an aspect of the present invention is an operation instruction system for a robot having a robot coordinate system, and an indicator that indicates a measurement point in space, A digitizer having a digitizer coordinate system, generating coordinate data in the digitizer coordinate system of the measurement point designated by the pointing tool, coordinate conversion between the digitizer coordinate system and the robot coordinate system, and by the digitizer A robot control unit that instructs the robot to perform an operation based on the coordinate data of the generated measurement points in the digitizer coordinate system.

  The robot control unit operates the robot so that the control target point moves toward the measurement point when the control target point of the robot is designated and the measurement point of the robot is instructed by the pointing tool. May be indicated.

  The robot control unit generates a rotation axis that passes through the third measurement point and the fourth measurement point when different third measurement points and fourth measurement points are instructed by the pointing tool, The robot may be instructed to operate so that a part of the robot set in advance rotates around the rotation axis.

  When the fifth measuring point is instructed by the pointing tool, the robot control unit sets the fifth measuring point in the same direction as a straight line connecting the third measuring point and the fourth measuring point. A rotation axis that passes through may be generated, and an operation may be instructed to the robot such that a part of a preset robot rotates around the rotation axis.

  The operation instruction system for the robot includes an input device for inputting information related to the operation of the robot, and the robot control unit instructs the robot to perform an operation according to the information input by the input device. May be.

  The robot control unit may instruct the robot to operate so that the robot moves or rotates at the input movement speed or rotation speed when a movement speed or rotation speed is input by the input device.

  The robot control unit moves the robot and moves at least one specific part of the robot to at least three parts. The coordinate data in the digitizer coordinate system of the specific part at each moving position; When coordinate data in the robot coordinate system is given, a value obtained by converting one of coordinate data in the digitizer coordinate system and coordinate data in the robot coordinate system by the coordinate conversion matches the other value. Furthermore, the coordinate transformation between the digitizer coordinate system and the robot coordinate system may be calculated.

  The robot has a flange portion having a flange coordinate system, and the robot control device performs coordinate conversion between the flange coordinate system and the robot coordinate system, and at least three of the flange portion and the front end side of the flange portion. Calculating and storing a tool vector of the at least three feature points in the flange coordinate system based on coordinate data of the digitizer coordinate system of the feature points and coordinate conversion between the digitizer coordinate system and the robot coordinate system; Thereafter, when the digitizer is moved and the coordinate data of the at least three feature points in the digitizer coordinate system is given, the coordinate data in the digitizer coordinate system of the given three feature points is converted into the digitizer coordinate system. And a value transformed by coordinate transformation between the robot coordinate system and The digitizer coordinate system after the digitizer has been moved so that the values obtained by transforming the tool vectors of the at least three feature points in the flange coordinate system by coordinate transformation between the flange coordinate system and the robot coordinate system match. And the coordinate transformation between the robot coordinate system and the robot coordinate system may be calculated.

  The robot control device assigns a predetermined motion to a predetermined region in the space in advance, and when a measurement point in the predetermined region is instructed by the pointing tool, the assigned motion is transmitted to the robot. You may instruct.

  An operation instruction method for a robot according to an aspect of the present invention is an operation instruction method for a robot having a robot coordinate system, the step of instructing a measurement point in space by an indicator, and a digitizer having a digitizer coordinate system Generating coordinate data in the digitizer coordinate system of the measurement point instructed by the pointing tool, coordinate conversion between the digitizer coordinate system and the robot coordinate system, and the measurement point generated by the digitizer Instructing the robot to operate based on the coordinate data in the digitizer coordinate system.

  According to the present invention, the operation of the operation instruction system can be facilitated.

It is a figure which shows the structure of the operation instruction | indication system to the robot which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the input terminal of the operation | movement instruction system of FIG. It is a flowchart which shows an example of the procedure of the preparation work in the operation | movement instruction system of FIG. It is the schematic of the system at the time of performing the preparatory work of FIG. It is a flowchart which shows an example of the operation | work in the operation | movement instruction system of FIG. It is the schematic of the system for demonstrating the operation | work of FIG. It is a figure for demonstrating the operation | work of Embodiment 2 of this invention. It is the schematic which expanded the tool front end attached to the robot of FIG. It is the schematic of the system for demonstrating the update registration of a tool. It is the schematic for demonstrating the instruction | indication of rotation in the operation instruction | indication system to a robot. It is a flowchart which shows an example of the calculation procedure of the new coordinate transformation accompanying the digitizer transfer of an operation instruction system. It is a system schematic for demonstrating the procedure before digitizer transfer of FIG. It is a system schematic for demonstrating the procedure after digitizer transfer of FIG. It is the system schematic for demonstrating the instruction | indication of the other operation | movement to a robot.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(Configuration of the embodiment)
FIG. 1 shows a configuration of an operation instruction system 1 for a robot according to Embodiment 1 of the present invention. As shown in FIG. 1, an operation instruction system 1 for a robot includes a robot 2, an indicating tool 3, a digitizer 4, a robot control unit 6, and an input terminal 7. These devices communicate with each other by wire or wirelessly. Connected as possible. In the operation instruction system 1 for the robot, the worker 100 performs work using the pointing tool 3. The robot control unit 6 includes a device (not shown) for driving the robot 2, a memory (not shown) for storing information, and a calculation unit (not shown) for performing calculations. Yes. The robot controller 6 is not limited to a single device. For example, the robot controller 6 is divided into a device that realizes a part of the functions of the robot controller 6 and another device that realizes other functions of the robot controller 6. May be. A general-purpose computer may be included as part of the robot controller 6. In short, what is necessary is just to perform the function of the robot controller 6 as a whole.

  The robot 2 is a robot that performs work on the workpiece W. In the present embodiment, an industrial robot is assumed. However, the robot 2 is not limited thereto, and may be a home robot, for example. In the present embodiment, the robot 2 includes a base (base) 10 installed on a mounting surface such as a floor surface, and an arm 11 protruding from the base 10. A coordinate system based on the upper surface of the base 10 is referred to as a robot coordinate system 20b. The arm 11 is provided with a plurality of joints 11a to 11d driven by a command from the robot controller 6, and a flange-like tool attachment portion 11e (hereinafter also referred to as “flange”) is provided at the tip thereof. Yes. A coordinate system based on the flange 11e is referred to as a flange coordinate system 20f. The joint may be rotationally driven or linearly driven. Adjacent joints are connected by links.

  Encoders (not shown) capable of detecting the angles of the respective joints are incorporated in the joints 11a to 11d, and the flanges 11e have different angles depending on the angles of the joints 11a to 11d and the dimensions of the links constituting the arms 11. The position and posture in the robot coordinate system 20b can be specified. A tool 12 is attached to the flange 11e. In the example of FIG. 1, an end mill having a tip at the tip is used as the tool 12. In addition, the workpiece | work W which is the work object of the robot 2 is not specifically limited.

  In the following, “moving the control target point of the robot 2 (for example, the tip of the tool 12)” may be simplified and expressed as “moving the robot 2”. Further, “rotating the control target portion of the robot 2 (for example, the entire tool 12)” may be simplified and expressed as “rotating the robot 2”. In addition, the “action” includes opening and closing of the hand in addition to movement and rotation of the robot 2.

  The indicator 3 indicates a measurement point in the real space. “Measurement point” means a position on the space to be measured by the digitizer 4, and “indicate the measurement point” means that the digitizer 4 recognizes the position on the space to be measured. means. In the present embodiment, the pointing tool 3 has a pen-shaped portion, and the worker 100 instructs an arbitrary measurement point in the real space with the pen tip. The pointing tool 3 can be used to specify a measurement point on the robot 2, the tool 12, or the workpiece W, and other measurement points can be specified.

  In addition, the indicator 3 emits energy waves such as beam-like light, radio waves, and ultrasonic waves from the tip, and the digitizer 4 can recognize the tip or the part of the object irradiated with the energy wave. (For example, a laser pointer) may be used. The measurement point in this case may be a laser pointer or a pen tip itself, or a part (irradiation spot) on another object indicated by light or radio waves emitted from the laser pointer or the pen tip. As will be described later, the pointing tool 3 may be an operator's finger, and the measurement point may be the position of the fingertip.

  The digitizer 4 is a general term for devices that generate coordinate data of a measurement point designated by the pointing tool 3 in a predetermined coordinate system (hereinafter referred to as “digitizer coordinate system 20d”). As the digitizer 4, a known one can be used. In the present embodiment, the digitizer 4 is a so-called stereo vision type digitizer, and includes two left and right imaging devices (not shown) and arithmetic means (not shown). The digitizer 4 generates coordinate data (x, y, z) of measurement points by performing arithmetic processing on the image data generated by each imaging device based on triangulation, and the generated coordinate data of the measurement points is transmitted to the robot. Output to the control unit 6. The digitizer may be a magnetic detection method, a method using a laser interferometer, or other known devices. When the operator's finger is used as the pointing tool 3, for example, Leap Motion Controller (registered trademark), which is a well-known product, performs three-dimensional imaging with two infrared cameras installed upward, and the image is obtained. The coordinate data may be generated using the position of the fingertip in space as a measurement point.

  In the manual mode, the robot control unit 6 controls the operation of the robot 2 based on the information on the measurement point designated by the pointing tool 3. The robot controller 6 may have an automatic mode for controlling the operation of the robot 2 according to the operation program. Also, the robot control unit 6 converts the coordinate data of the measurement points generated by the digitizer 4 in the digitizer coordinate system 20d into coordinate data in the robot coordinate system 20b, and calculates a movement locus based on the converted coordinate data. To instruct the robot 2 to operate.

  Note that the positions and orientations of the digitizer coordinate system 20d and the robot coordinate system 20b can be arbitrarily set, and the two coordinate systems may coincide. In this case, the coordinate conversion between these coordinate systems means that the coordinate data in one coordinate system is directly used as the coordinate data in the other coordinate system. This is equivalent to performing coordinate transformation using a coordinate transformation matrix that is a unit matrix.

  The input terminal 7 is an input device used by the worker 100 to input information related to the operation to the robot control unit 6. The robot control unit 6 instructs the robot 2 to operate according to information output from the input terminal 7. The input terminal 7 will be described in detail later.

  FIG. 2 is a perspective view showing the configuration of the input terminal 7. As illustrated in FIG. 2, the input terminal 7 includes a main body 71 provided with various keys 71 a to 71 d and a holding unit 72 for the operator 100 to hold the input terminal 7. The key 71a is a key for switching or updating a tool (hereinafter also referred to as “tool switching / update key”). The key 71b is a key for switching the operation of the robot 2 between movement and rotation (hereinafter also referred to as “movement / rotation switching key”). The key 71c is a key for instructing the robot 2 to perform a predetermined operation assigned in advance to a predetermined area in the real space (hereinafter also referred to as an “assignment operation key”). The key 71d is for changing the moving speed of the robot 2 (hereinafter also referred to as “speed volume”). The movement speed or rotation speed of the robot changes according to the rotation amount of the volume, and the robot can be operated at various speeds. Here, when the moving speed or the rotational speed is zero, it means “stop”. Further, the key 71d may be configured such that when operated on one side, the robot 2 moves in the positive direction according to the operation amount, and when operated on the other side, the robot 2 moves in the negative direction according to the operation amount (hereinafter referred to as the key 71d). , "Jog feed"). The robot 2 may be configured to stop when the hand is released from the key 71d, or the key 71d is returned to a predetermined position (for example, a position where the moving speed is zero) when the hand is released from the key 71d. It may be configured. In the present embodiment, the input terminal 7 is configured to output information to the robot control unit 6 based on information input by the various keys 71a to 71d.

  With the above configuration, the worker 100 can perform work using the input terminal 7 while visually confirming the operation of the robot 2. In particular, the operator 100 can decrease the speed of the robot 2 or stop the robot 2 before the tool and the workpiece come into contact with each other by operating the speed volume.

(preparation work)
Next, operations in the robot operation instruction system 1 will be described. Prior to the work, the worker 100 performs a preparatory work for calculating a coordinate transformation between the robot coordinate system 20b and the digitizer coordinate system 20d. FIG. 3 is a flowchart illustrating an example of a procedure of preparation work in the operation instruction system 1 for the robot. FIG. 4 is a schematic diagram of the system when the preparation work of FIG. 3 is performed.

  First, the robot control unit 6 uses the coordinate data bX1 of the point on the robot 2 (for example, the tip of the tool 12) in the robot coordinate system 20b, the angles of the joints 11a to 11d, the dimensions of the links constituting the arm 11, and the tool 12. (Step 31). Next, the operator 100 points the point on the robot 2 with the pointing tool 3, and the digitizer 4 generates coordinate data dX1 in the digitizer coordinate system 20d of the measurement point pointed by the pointing tool 3 (step 32). . The worker 100 moves the robot 2 (step 33). By repeating the steps so far at least three times, coordinate data bX1 to bX3 and coordinate data dX1 to dX3 are obtained. Next, the robot control unit 6 minimizes the error between the coordinate data dX1 to dX3 transformed by the coordinate transformation matrix bRd so that they coincide with the coordinate data bX1 to bX3, respectively, or not. Thus, the coordinate transformation matrix bRd is calculated (step 34). In the coordinate transformation matrix bRd, “b” means the robot coordinate system 20b, “d” means the digitizer coordinate system 20d, and “bRd” is a coordinate transformation matrix between the robot coordinate system 20b and the digitizer coordinate system 20d. I mean. Unless otherwise noted, the same applies below. In the following description, it is assumed that the coordinate transformation matrix between the robot coordinate system 20b and the digitizer coordinate system 20d is calculated in advance by a preparatory work.

When the tool 12 is attached to the flange 11e, the coordinate data bX1 to bX3 includes the tool vector fXt from the flange position in the flange coordinate system 20f to a predetermined point (for example, the tip) of the tool 12, and the flange coordinate system 20f. And the coordinate transformation matrix bRf between the robot coordinate system 20b and the equations (1) to (3). In the following, the product of a matrix and a vector is represented by *. In the coordinate transformation matrix bRf, “b” means the robot coordinate system 20b, and “f” means the flange coordinate system 20f, respectively.
bX1 = bRf1 * fXt (1)
bX2 = bRf2 * fXt (2)
bX3 = bRf3 * fXt (3)

  Here, the tool vector fXt is obtained in advance by calculation or measurement based on the design information and stored in the robot controller 6. The coordinate transformation matrix bRf is calculated by the robot controller 6 from the encoder value of the robot 2 and the link dimensions. In the equations (1) to (3), the coordinate conversion matrix bRf is distinguished by adding subscripts 1 to 3 because the encoder value of the robot 2 changes due to the movement of the robot 2 in step 33. On the other hand, the values of the tool vector fXt are the same in the expressions (1) to (3).

  The preparatory work described above is an example, and conversion between coordinate systems may be calculated by measuring the relative positions and postures of the robot 2 and the digitizer 4.

(Direction of movement)
Next, a case where the robot 2 is instructed to move will be described with reference to FIGS. The operation in the robot operation instruction system 1 is performed using the coordinate transformation matrix bRd. FIG. 5 is a flowchart showing an example of work in the operation instruction system 1 for the robot. FIG. 6 is a schematic diagram of a system for explaining the operation of FIG.

First, as shown in FIG. 6A, coordinate data bX1 of a control target point P1 (hereinafter referred to as “point P1”) of the robot 2 is designated (step 51). The operator 100 instructs the point P1 on the robot 2 (for example, the tip of the tool 12) with the pointing tool 3. The digitizer 4 generates coordinate data dX1 in the digitizer coordinate system 20d of the measurement point designated by the pointing tool 3. Then, coordinate data bX1 is calculated by the following equation (4) based on the generated coordinate data dX1 and the coordinate transformation matrix bRd. The method for designating the coordinate data bX1 of the point P1 may be other methods described later.
bX1 = bRd * dX1 (4)

Next, as shown in FIG. 6B, the operator 100 designates the target point P <b> 2 on the workpiece W with the pointing tool 3, and the digitizer coordinate system of the measurement point designated by the digitizer 4 with the pointing tool 3. The coordinate data dX2 at 20d is generated (step 52). Next, as shown in FIG. 6C, the robot controller 6 calculates the coordinate data bX2 by the following equation (5) based on the coordinate data dX2 and the coordinate transformation matrix bRd, the target point P2, the robot The robot 2 is moved so that the point P1 moves along a movement locus (a two-dot chain line arrow in the figure) connecting the point P1 (hereinafter referred to as “starting point P1 ′”) before instructing the movement to 2. (Step 53).
bX2 = bRd * dX2 (5)

  As other methods for designating the point P1, for example, (a) a method in which information on the point P1 is stored in the robot control unit 6 in advance, and (b) a method in which a point other than on the robot 2 is designated by the pointing tool 3. Exists. In short, it suffices if the control target point of the robot 2 can be designated. Hereinafter, (a) and (b) will be described.

(A) Method for storing information on point P1 in advance in robot controller 6 For example, the tool vector from the position of the point P1 to the point on the robot 2 (for example, the tip of the tool 12) from the flange position in the flange coordinate system 20f. It may be stored in the robot controller 6 in the form of fXt in advance, and the coordinate data bX1 may be calculated by the following equation (4-1) based on the tool vector fXt and the coordinate transformation matrix bRf.
bX1 = bRf * fXt (4-1)

(B) Method of Instructing Point Except on Robot 2 with Pointer 3 The operator 100 points to a point P1 other than the point on the robot 2 (for example, near the tool 12) with the pointer 3. The digitizer 4 generates coordinate data dX1 ′ in the digitizer coordinate system 20d at the measurement point designated by the pointing tool 3. In addition, the coordinate data bX1 may be calculated by the following equation (4-2) based on the generated coordinate data dX1 ′ and the coordinate conversion matrix bRd.
bX1 = bRd * dX1 '(4-2)

  As described above, points other than the robot 2 can be regarded as points on the robot 2 and can be used as the control target points of the robot 2, but the coordinate data dX1 ′ is associated with the points on the robot 2 and associated. It is also possible to calculate the coordinate data bX1 in the same manner as (b) above, assuming that the coordinate data of the point on the robot 2 is dX1. For example, the coordinate data of the point on the robot 2 closest to the point represented by the coordinate data dX1 'can be dX1.

  When moving, the robot 2 can be moved at a speed corresponding to the operation amount of the “speed volume” of the input terminal 7. Alternatively, the input terminal 7 may be provided with a jog feed key or volume (not shown), and the point P1 may be moved by a movement amount corresponding to the operation amount. In this case, for example, the point P1 moves on a straight line connecting the starting point P1 'and the target point P2. The point P1 moves not only between the starting point P1 ′ and the target point P2, but also on the opposite side of the target point P2 when viewed from the starting point P1 ′ and the opposite side of the starting point P1 ′ when viewed from the target point P2. Also good.

  With the configuration as described in steps 51 to 53 above, it is possible to determine the moving direction of the robot 2 simply by instructing the actual tool 12 or workpiece W of the robot 2 with the pointing tool 3, and to instruct the robot 2 to operate. it can. Therefore, the operator can work intuitively and efficiently without being aware of the coordinate system and tool setting.

  Note that a contact detecting means (for example, a contact sensor) for detecting that the pointing tool 3 is in contact (touched) with an object (for example, the tool 12 or the workpiece W) is provided in the pointing tool 3, and Measurement may be performed based on the output of the contact detection means. Also, a key (not shown) for inputting the measurement timing by the digitizer 4 may be provided on the pointing tool 3 or the input terminal 7 so that the measurement point is measured by the digitizer 4 at the timing when the key is operated. Good.

  When the point P1 and the target point P2 are instructed by the pointing tool 3, the point P1 and the target point P2 can be configured to be distinguished according to the measurement order of the respective measurement points. Further, a key (not shown) for inputting the measurement timing of the point P1 by the digitizer 4 and a key (not shown) for inputting the measurement timing of the target point P2 by the digitizer 4 are indicated on the indicator 3 and the input terminal 7. It may be configured to distinguish between the measurement timing of the point P1 and the measurement timing of the target point P2 based on the operation of the key. The point P1 and the target point P2 may be distinguished depending on whether the measurement point is in the vicinity of the existence range of the robot 2 or the tool 12 or in the vicinity of the existence range of the workpiece W.

  In the above description, the movement trajectory of the robot 2 is a straight line connecting the starting point P1 'and the target point P2, but various other movement trajectories can be employed. For example, it may be a movement trajectory in which the travel time from the starting point P1 'to the target point P2 is the shortest, or a moving trajectory that avoids an obstacle existing between the starting point P1' and the target point P2. By providing a key (not shown) for inputting the type of movement locus connecting the starting point P1 'and the target point P2 on the pointing tool 3 or the input terminal 7, the type of movement locus may be selectable. Further, when the point P1 moves, the tool 12 may move in parallel without changing the posture, or the tool 12 may change the posture.

Next, a specific example of work will be described with reference to FIG. As shown in FIG. 7A, in this example, the information of the point P1 is stored in advance in the robot controller 6 in the form of a tool vector fXt from the flange position in the flange coordinate system 20f to the tip of the tool 12. . The operator 100 designates the target point P2 with the pointing tool 3, and the digitizer 4 generates coordinate data dX2 in the digitizer coordinate system 20d of the target point P2 designated with the pointing tool 3. Next, the robot control unit 6 uses the generated coordinate data dX2, the tool vector fXt stored in the robot control unit 6, the coordinate conversion matrix bRd, and the coordinate conversion matrix bRf1 calculated by the robot control unit 6. The coordinate data bX1 and bX2 are calculated from (6) and (7).
bX1 = bRf1 * fXt (6)
bX2 = bRd * dX2 (7)

  Then, the robot control unit 6 instructs the robot 2 to operate so that the point P1 moves from the starting point P1 'toward the target point P2. Next, as shown in FIG. 7B, the operator 100 designates a new target point P2a by the pointing tool 3, and the digitizer coordinate system 20d of the new target point P2a designated by the pointing tool 3 is designated by the digitizer 4. The coordinate data dX2a at is generated. Next, the robot control unit 6 uses the generated coordinate data dX2a, the tool vector fXt stored in the robot control unit 6, the coordinate conversion matrix bRd, and the coordinate conversion matrix bRf2 calculated by the robot control unit 6. Similar to (6) and (7), new coordinate data bX1, bX2 are calculated. Then, the robot control unit 6 instructs the robot 2 to operate so that the point P1 moves toward the new target point P2a. Thereafter, similarly, the robot 2 is instructed to operate by instructing new target points P2a one after another.

  In the above description, the tool vector fXt is stored in the robot controller 6 because the tool vector is constant regardless of the angles of the joints 11a to 11d of the robot 2. That is, if the tool vector information is stored, the coordinate data bX1 of the point P1 in the robot coordinate system 20b can be calculated by using the coordinate transformation matrix bRf calculated from the angles of the joints 11a to 11d. . Thus, the flange 11e has a meaning of a boundary between the base end side that is affected by the angle change of the joints 11a to 11d and the front end side that is not affected by the angle change of the joints 11a to 11d. In other words, in the above description, the items described with reference to the flange 11e (for example, items related to the flange coordinate system 20f) are the boundaries that separate the “flange 11e” in the description from the presence or absence of the influence of the angle change of the joints 11a to 11d. Even if it is replaced with an arbitrary point in the region (hereinafter referred to as “flange portion”), it is also established. The “tool 12” may be present on the distal end side of the flange portion and may include the flange portion.

Next, as shown in FIG. 8, the case where the tool 12 is moved to a position where the edge of the tool tip 12a contacts the plane of the workpiece W of the tool 12 having a cylindrical tip (for example, a welding torch) will be described. To do. It is assumed that the point P1 exists at the center of the tip of the cylindrical portion. In this case, when a point on the plane of the workpiece W, which is the target point, is designated as a new target point P2a and the robot 2 is instructed to operate, the tip of the tool 12 is placed on the workpiece W as shown in FIG. 12a interferes. Therefore, as shown in FIG. 8B, it is necessary to store the edge of the cylinder (part to be contacted) in the robot control unit 6 as a new point P1. For this purpose, as shown in FIG. 9, first, the operator 100 designates a new point P1 with the pointing tool 3, and the digitizer 4 coordinates the point P1 designated with the pointing tool 3 in the digitizer coordinate system 20d. Data dX1 is generated. Next, the robot control unit 6 calculates a tool vector (vector from the flange 11e to the point P1) fXt_new by the equations (8) and (9) using the coordinate transformation matrices bRd and bRf, and uses this to calculate the robot control unit 6 is stored. This is called “tool update”. Here, inv (bRf1) is an inverse matrix of bRf1.
bX1 = bRd * dX1 (8)
fXt_new = inv (bRf) * bX1 (9)

  In the above description, the case where the point P1 moves from the starting point P1 ′ toward the target point P2 has been described. However, the robot 2 is stopped while the point P1 moves toward the target point P2, and a new target is obtained. Point P2a can also be indicated. Specifically, it is as follows. That is, the robot control unit 6 calculates the coordinate transformation matrix bRf when the robot 2 is stopped. The operator 100 designates a new target point P2a by the pointing tool 3, and the digitizer 4 generates coordinate data dX2a in the digitizer coordinate system 20d of the new target point P2a designated by the pointing tool 3. Next, the robot control unit 6 uses the generated coordinate data dX2a, the stored tool vector fXt, the calculated coordinate transformation matrix bRf, and the coordinate transformation matrix bRd, as in Expressions (6) and (7). Calculate the coordinate data bX1, bX2. Then, the robot controller 6 instructs the robot to operate so that the point P1 moves from the starting point P1 'toward the target point P2.

  By doing in this way, even when the worker 100 stops the robot 2 while the point P1 moves from the starting point P1 ′ toward the target point P2, the worker 100 instructs the new target point P2a. The point P1 can be easily moved to the correct position.

  Here, information on a plurality of candidates for the point P1 may be stored in the robot control unit 6 so that the point P1 to be used can be switched. This is called “tool switching”. By doing in this way, the information of the point P1 in a some tool and the information of the some candidate of the point P1 with respect to a single tool can be memorize | stored in the robot control part 6. FIG. Tool update and tool switching as described above may be executed when the tool switch / update key 71a of the input terminal 7 is pressed. For example, each time the tool switching key 71a is pressed, the selected one of the plurality of candidates for the point P1 may be switched. When the tool switching key 71a is pressed, the touch panel (see FIG. (Not shown), a plurality of candidates for the point P1 may be displayed, and the touch panel may be operated to select from among the plurality of candidates for the point P1.

(Rotation instruction)
Hereinafter, a case where the robot 2 is instructed to rotate will be described. FIG. 10A is a schematic diagram for explaining a rotation instruction. First, in order to switch from movement to rotation, the “movement / rotation switching key” 71b provided on the input terminal 7 is switched to the rotation side. Next, the direction of the rotation axis is specified. Here, as shown in FIG. 10A, a point P3 (third measurement point) and a point P4 (fourth measurement point) are designated by the pointing tool 3 (pen tip). For example, when it is desired to specify a rotation axis parallel to the edge on the tool 12, the digitizer 4 generates coordinate data dX3 with the pen point aligned with the point P3 on the edge of the tool 12, and then the edge of the tool 12 The coordinate data dX4 is generated by the digitizer 4 in a state where the upper point P4 is aligned with the pen tip. Next, the position of the rotation axis is specified. Here, the coordinate data dX5 is generated by the digitizer 4 with the pen tip aligned with the point G (fifth measurement point) on the workpiece W. Based on the coordinate transformation matrix bRd and the generated coordinate data dX3 to dX5, the robot controller 6 calculates a rotation axis that passes through the point G in the same direction as the straight line connecting the points P3 and P4. FIG. 10B is a schematic diagram when the tool 12 is rotated around the calculated rotation axis as shown in FIG. This schematic diagram shows the tool 12 and the workpiece W as seen from the direction of arrow A in FIG. When actually rotating, the robot 2 can be rotated at a speed corresponding to the operation amount of the “speed volume” of the input terminal 7.

  With the configuration as described above, it is possible to easily set a desired rotation axis and instruct the robot 2 to rotate.

  In the above description, the object to be rotated is the entire tool 12, but the object to be rotated is not limited to the entire tool 12 as long as it is a part of a preset robot.

  Alternatively, the fifth measurement point may not be specified, and a straight line passing through the third measurement point and the fourth measurement point may be used as the rotation axis. As the fifth measurement point, the tip of the tool 12 or the like may be designated in advance. As the rotation direction, the rotation direction of the so-called right screw may be a positive rotation direction and the opposite is the negative rotation direction with respect to the direction from the third measurement point to the fourth measurement point.

(Teaching)
When the robot is instructed to move or rotate, and when the robot reaches a desired position / posture, the robot control unit 6 stores the position / posture or joint angle of the robot at that time (refer to “ The teaching tool 3 or the input terminal 7 may be provided with a teaching key (not shown).

(Relocation of digitizer)
Below, the case where the digitizer 4 is moved in the operation | movement instruction | indication system 1 to a robot is demonstrated. FIG. 11 is a flowchart showing an example of a procedure for calculating a new coordinate transformation matrix accompanying the relocation of the digitizer 4. Here, it is assumed that the worker 100 calculates the coordinate transformation matrix bRd for the digitizer 4 before relocation in the same procedure as in the first embodiment. FIG. 12 is a system schematic diagram for explaining a procedure before the digitizer is moved. As shown in FIG. 12, the operator 100 indicates at least three feature points on the tip side (for example, the tool 12) from the flange 11e by the pointing tool 3, and generates coordinate data dXp1 to dXp3 by the digitizer 4 (step). 101). Here, the “feature point” is a point designated by the pointing tool 3 before and after the digitizer 4 is moved, and may be an arbitrary point, but may be a corner of a member (see FIG. 12), marking, It is preferable that the point has a characteristic that an operator can easily instruct.

  Then, the robot controller 6 calculates a coordinate transformation matrix bRf3 between the flange coordinate system 20f and the robot coordinate system 20b (step 102). Next, the robot controller 6 calculates and stores tool vectors fXp1 to fXp3 from the flange 11e to each feature point based on the generated dXp1 to dXp3 and the calculated coordinate transformation matrix bRf3 (step 103).

Next, the worker 100 performs the work after the digitizer is moved. FIG. 13 is a system schematic diagram for explaining a procedure after the digitizer is moved. As shown in FIG. 13, the worker 100 instructs again the feature point instructed by the indicator 3 in the above-described procedure, and measures it with the digitizer 4 after the transfer to generate coordinate data aXp1 to aXp3. (Step 104). Then, the robot control unit 6 calculates a coordinate transformation matrix bRf4, and coordinates in the robot coordinate system using the following equations (10) to (12) based on the stored tool vectors fXp1 to fXp3 and the calculated coordinate transformation matrix bRf4. Calculate the data.
bXp1 = bRf4 * fXp1 (10)
bXp2 = bRf4 * fXp2 (11)
bXp3 = bRf4 * fXp3 (12)

  Next, the robot control unit 6 converts the coordinate data aXp1 to aXp3 generated by the digitizer 4 after relocation using the coordinate conversion matrix bRd_new to match the new coordinate data bXp1 to bXp3. A transformation matrix bRd_new is calculated (step 105).

  According to this procedure, after the digitizer 4 is moved, the operator 100 can update the coordinate transformation matrix only by touching three feature points with the pointing tool (pen nib) 3, so that the work is easy. This is particularly effective when a small and portable digitizer 4 is used in the operation instruction system 1 for the robot, or when it is desired to indicate a measurement point that cannot be measured from the current position of the digitizer 4.

  This procedure is performed when the posture of the robot 2 changes before and after the digitizer 4 is moved (when the coordinate transformation matrix bRf3 and the coordinate transformation matrix bRf4 are different) and when the robot 2 does not change (the coordinate transformation matrix bRf3 and the coordinate transformation matrix bRf4 are the same). In both cases). When the posture of the robot 2 does not change before and after the digitizer 4 is moved, the coordinate data of the feature point indicated by the pointing tool 3 in the digitizer coordinate system 20d is compared before and after the digitizer 4 is moved. It is also possible to calculate the movement amount and the rotation amount or information equivalent thereto, and to calculate a new coordinate transformation matrix bRd_new based on the calculated information and the coordinate transformation matrix bRd before the digitizer is moved.

(Action assignment function)
In the operation instruction system 1 for the robot, not only movement or rotation but also other movements can be instructed to the robot. When a predetermined motion is assigned to a predetermined area of the real space in advance and the “assignment operation key” of the input terminal 7 is pressed in a state where the area is designated by the pen tip of the digitizer, the assigned motion is 2 is instructed.

  FIG. 14 is a system schematic diagram for explaining another operation instruction method in the operation instruction system for the robot. Here, an example is shown in which an operation for independently driving the joint 11b is assigned to a predetermined region near the joint 11b. For example, as shown in FIG. 14, when the “assignment operation key” of the input terminal 7 is pressed with the pointing tool 3 pointing to the area 21 near the joint 11 b, the joint 11 b is driven alone. For example, the joint 11b may be driven independently at a rotational speed corresponding to the operation amount of the “speed volume” of the input terminal 7. Similarly, for a joint other than the joint 11b, an operation for driving the joint independently can be assigned to a predetermined region near the joint.

  As an operation assigned to the predetermined area, an operation based on a robot coordinate system reference, an operation such as opening and closing of a hand, etc. can be adopted in addition to single driving of a joint. Thus, the operator can easily instruct the robot to perform a desired operation using the input device.

  Further, the motion may be assigned with a region outside the robot motion range as a predetermined region. As a result, it is possible to easily distinguish the robot movement instruction and the movement instruction assigned to the predetermined area.

(Other embodiments)
In the embodiment, the input terminal 7 includes the main body 71 provided with various keys and the holding unit 72 held by the operator. However, the holding unit 72 can be used by being wrapped around the operator's arm. A simple wristband may be used, and the main body 71 may be attached to the wristband. Further, although the input terminal 7 is configured independently of the pointing tool 3 (pen) of the digitizer 4, it may be configured integrally with the pointing tool 3 (pen). The pointing tool 3 or the input terminal 7 may have a display unit (not shown), and an object to be pointed by the pointing tool 3 may be displayed on the display unit. The pointing tool 3, the input terminal 7, or the robot control unit 6 may have a voice system (not shown), and a target to be pointed by the pointing tool 3 may be guided by voice. In this case, a key for starting voice guidance may be provided on the pointing device 3 or the input terminal 7.

  Further, the pointing tool 3 and the input terminal 7 may be used together with the teaching pendant, or may also serve as the teaching pendant.

  Further, a deadman switch may be provided on the pointing tool 3 or the input terminal 7.

  In the above description, the pointing tool 3 indicates a measurement point in the real space. However, the present invention is not limited to this, and the measurement point may be specified in a space other than the real space, such as a virtual reality space. In any case, the operator can directly and intuitively instruct operation by directly instructing the robot 2 in the three-dimensional space.

  The indicator 3 may have two or more points for instruction. By doing so, it becomes possible to easily and directly specify the direction of operation and the rotation axis. For example, one point for pointing is positioned at the tip of the tool 12, and the direction from the one point for pointing to the other point for pointing is the direction in which the tip of the tool 12 is to be moved. In addition, the robot 2 may be instructed to move the tip of the tool 12 in a desired direction by positioning the other point for instruction. Alternatively, the robot 2 may be instructed to rotate with the direction of a straight line connecting one point for instruction and the other point for instruction as the direction of the rotation axis of the robot 2.

  The instruction of the target point P2 and the new target point P2a by the indicator 3 may be performed continuously or every arbitrary control cycle. In this way, the robot 2 can be instructed to move so that the point P1 follows the point for the pointing tool 3 to point.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of at least one of its structure and function can be substantially changed without departing from the spirit of the present invention.

  The present invention can be used for an operation instruction to a robot.

DESCRIPTION OF SYMBOLS 1 Operation instruction system to robot 2 Robot 3 Indicator 4 Digitizer 6 Robot control part 7 Input terminal 10 Base (base)
11 Arm 12 Tool 15 Work table 20b Robot coordinate system 20f Flange coordinate system 20d Digitizer coordinate system 21 Allocation area

Claims (9)

An operation instruction system for a robot having a robot coordinate system,
An indicator that indicates a measurement point in space;
A digitizer having a digitizer coordinate system and generating coordinate data in the digitizer coordinate system of the measurement point indicated by the indicator;
A robot control unit that instructs the robot to perform an operation based on coordinate conversion between the digitizer coordinate system and the robot coordinate system, and coordinate data in the digitizer coordinate system of measurement points generated by the digitizer;
With
The robot control unit is a point on the robot that is a control target point that is a control target when controlling the operation of the robot, and when the measurement point is instructed by the pointing tool, the control target An operation instruction system for a robot instructing the robot to perform an operation so that a point moves toward the measurement point . The robot control unit generates a rotation axis that passes through the third measurement point and the fourth measurement point when different third measurement points and fourth measurement points are instructed by the pointing tool, The operation instruction system for the robot according to claim 1 , wherein an operation is instructed to the robot such that a part of the preset robot rotates around the rotation axis. When the fifth measuring point is instructed by the pointing tool, the robot control unit sets the fifth measuring point in the same direction as a straight line connecting the third measuring point and the fourth measuring point. The robot operation instruction system according to claim 2 , wherein a rotation axis passing through the robot is generated, and the robot is instructed to move so that a part of the preset robot rotates around the rotation axis. The operation instruction system for the robot includes an input device for inputting information related to the operation of the robot, and the robot control unit instructs the robot to perform an operation according to the information input by the input device. The operation instruction system to the robot according to any one of claims 1 to 3 . 5. The robot controller according to claim 4 , wherein when a movement speed or a rotation speed is input by the input device, the robot control unit instructs the robot to move or rotate at the input movement speed or rotation speed. An operation instruction system for the described robot.   The robot control unit moves the robot and moves at least one specific part of the robot to at least three parts. The coordinate data in the digitizer coordinate system of the specific part at each moving position; When coordinate data in the robot coordinate system is given, a value obtained by converting one of coordinate data in the digitizer coordinate system and coordinate data in the robot coordinate system by the coordinate conversion matches the other value. The operation instruction system for the robot according to claim 1, further configured to calculate the coordinate transformation between the digitizer coordinate system and the robot coordinate system. The robot has a flange portion having a flange coordinate system;
The robot control device includes coordinate conversion between the flange coordinate system and the robot coordinate system, coordinate data in the digitizer coordinate system of the flange portion and at least three feature points on the tip side of the flange portion, and the digitizer coordinates. Calculating and storing a tool vector of the at least three feature points in the flange coordinate system based on a coordinate transformation between a system and the robot coordinate system; then, the digitizer is relocated, and the at least three features A value obtained by converting coordinate data of the given three feature points in the digitizer coordinate system by coordinate conversion between the digitizer coordinate system and the robot coordinate system when coordinate data of the point in the digitizer coordinate system is given And at least three features in the stored flange coordinate system The coordinates between the digitizer coordinate system and the robot coordinate system after the digitizer is moved so that the value obtained by converting the tool vector of the point by the coordinate conversion between the flange coordinate system and the robot coordinate system matches. The motion instruction system for the robot according to claim 1, wherein the motion instruction system is configured to calculate a transformation.   The robot control device assigns a predetermined motion to a predetermined region in the space in advance, and when a measurement point in the predetermined region is instructed by the pointing tool, the assigned motion is transmitted to the robot. The operation instruction system for the robot according to claim 1, wherein the instruction is performed. An operation instruction method for a robot having a robot coordinate system,
A step of indicating a measurement point in space by an indicator;
Generating coordinate data in the digitizer coordinate system of the measurement point indicated by the indicator by a digitizer having a digitizer coordinate system;
Instructing the robot to perform an operation based on coordinate conversion between the digitizer coordinate system and the robot coordinate system, and coordinate data in the digitizer coordinate system of measurement points generated by the digitizer;
including,
In the step of instructing the robot to operate, a point on the robot that is a target to be controlled when controlling the operation of the robot is specified, and the measurement point is instructed by the pointing tool A method for instructing the robot to instruct the robot to move so that the control target point moves toward the measurement point .
that's all

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