JP2010188432A - Position correction method of robot hand, robot hand, and robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position correction method of a robot hand capable of suitably executing teaching, and also to provide a robot hand, and further to provide a robot. <P>SOLUTION: The method corrects the position of the robot hand 300 when teaching a target position set on a workpiece 200 to the robot including a plurality of the joints and the robot hand 300 having a CCD camera 313. The method includes a recognition step of recognizing relative positional displacement of the robot hand 300 and the target position from a picked-up target mark and the reference position of the pick-up range of the CCD camera 313 by picking-up the target mark arranged at a bush 210 inserted into the target position with the CCD camera 313; and a first position correction step of correcting the position of the robot hand 300 by controlling the drive of the joints of the robot to reduce the recognized positional displacement. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a position correction method for a robot hand, a robot hand, and a robot.

  Conventionally, in teaching for teaching the target position of a robot hand to a robot, a human being teaches the target position one by one while checking the position and orientation of the robot at the site where the robot performs work.

  Further, when teaching the target position of the robot, a rough target position is also taught in advance by using a three-dimensional model that models the work site of the robot.

  Patent Documents 1 to 6 disclose techniques for correcting a deviation amount from a target position in teaching the target position to a robot. For example, in Patent Document 1, a correction tool having three sensors is provided at the tip of a robot hand with respect to the movement direction of the robot, and X is determined from the positional relationship with each surface of a rectangular parallelepiped arranged at right angles to the movement direction. There is disclosed a robot axis deviation correction method that can automatically correct axis deviations by calculating respective deviation amounts of the Y, Z axes.

JP-A-4-041188 JP-A-6-126671 Japanese Patent Laid-Open No. 7-075986 JP-A-8-029359 JP 2005-334998 A Japanese Patent No. 3904605

  However, since the target position of the robot hand varies depending on the assembly state of the gripping object, teaching may not be performed satisfactorily with the conventional method. For example, when the assembly accuracy of the gripping object installed at the work site is poor, extra time is required to align the robot position with the target position. Since such positioning is required for each gripping object, there is a problem that it takes a lot of time to teach the robot.

  Further, for example, the technique disclosed in Patent Document 1 has various problems described below. First, the technique disclosed in Patent Document 1 requires three sensors to detect the relative position between the robot and the target position, and further includes a system for correcting the position after detecting the relative position. Since the interface, the control device, the memory function, and the like are included, the configuration of the calculation unit is complicated and expensive. In addition, in such a configuration, the control logic becomes complicated, so that it is difficult to identify the problem when a malfunction of the arithmetic unit occurs. Furthermore, even if a relative positional deviation can be detected, if there are multiple target positions to be taught, it will be difficult to use in teaching because there will be a trouble of correcting each target position depending on the installation accuracy of the equipment. It is. Furthermore, when detecting corrections in teaching, it is necessary to check visually from a short distance, which is not suitable for teaching from a wide range, which is performed by a person outside the fence surrounding the work site based on safety, etc. There is a problem.

  Therefore, the present invention provides a robot hand position that can perform teaching from a wide range to a narrow range inexpensively and easily, and can perform teaching accurately and inexpensively and easily. An object is to provide a correction method, a robot hand, and a robot.

  In the robot hand position correcting method according to the first aspect of the present invention, when a target position set for a workpiece is taught to a robot including a plurality of joints and a robot hand having an imaging unit, A method of correcting the position of a robot hand, wherein a target mark provided with reference to the target position is imaged by the imaging unit, and the captured target mark and a reference position of an imaging range of the imaging unit are A recognition step of recognizing a relative positional deviation between the robot hand and the target position; and a correction of the position of the robot hand by controlling the driving of the joints of the robot so that the recognized positional deviation is reduced. 1 position correction step.

  As a result, the relative position deviation from the target position is recognized by the target mark imaged by the imaging unit of the robot hand, and the robot joint drive is controlled so that the position deviation is reduced, thereby preventing the robot from moving. Even when teaching a target position from a wide range to a narrow range, it is possible to carry out the teaching by correcting the position of the robot hand easily and inexpensively.

  In the robot hand position correcting method according to the second aspect of the present invention, a bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with reference to the target position. The center of the target mark and the reference position of the imaging unit in a state where the robot hand is moved to the target position and is opposed to the workpiece in the central portion on the side facing the target mark. Are arranged on the same axis, and the first position correction step is performed so that the center of the target mark and the reference position of the imaging unit overlap each other. The position of the robot hand is corrected by controlling the driving of the joint. Thereby, it is possible to more easily recognize the relative positional deviation between the robot hand and the target position.

  In the robot hand position correcting method according to the third aspect of the present invention, the robot hand is provided with a bush gripping portion for gripping the bush by fitting on the side facing the bush. An inner peripheral surface of the bush gripping portion that comes into contact is formed in a taper shape, and further includes a bush gripping step that controls the drive of the joint of the robot to cause the bush gripping portion to grip the bush. Thereby, the bush can be easily grasped.

  In a robot hand position correcting method according to a fourth aspect of the present invention, a bush is inserted into the workpiece, and the target mark is provided on the side facing the robot hand on the side facing the robot hand. The robot hand includes a bush gripping portion that fits and grips the bush on a side facing the bush, and a float portion that holds the bush gripping portion and is movable in a horizontal plane. And a bush holding step for fixing the position of the bush holding portion with respect to the bush when the bush is inserted into the bush holding portion. This makes it possible to clarify the positional relationship between the center of the robot hand and the center of the target mark of the bush by fixing the position of the bush holding part of the robot hand and the bush when the bush is inserted. it can.

  In the robot hand position correcting method according to the fifth aspect of the present invention, the robot hand is provided with a displacement amount detection unit for detecting a displacement amount of the bush holding portion with respect to a reference position of the robot hand in the horizontal plane. When the bush is gripped by the bush gripping portion and the position of the bush gripping portion with respect to the bush is fixed by the chuck portion, the shift amount detection unit detects the shift amount in the horizontal plane. A displacement amount detection step, and a second position correction step of correcting the position of the robot hand by controlling the drive of the joint of the robot so as to reduce the detected displacement amount. As a result, even when the target position up to a more detailed range is taught to the robot, the position correction of the robot hand can be performed with high accuracy and ease.

  In a robot hand position correcting method according to a sixth aspect of the present invention, the displacement amount detection unit includes a displacement sensor that is provided in the robot hand and detects a displacement amount in a direction perpendicular to the horizontal plane, and the float unit includes A contact portion that is in contact with the displacement sensor, and the contact portion changes a position of a contact point that contacts the displacement sensor according to a movement amount of the float portion from a reference position in the horizontal plane. The displacement amount detecting step is performed by the displacement sensor when the bush is gripped by the bush gripping portion and the position of the bush gripping portion with respect to the bush is fixed by the chuck portion. A displacement amount is detected, and the detected displacement amount is converted into a displacement amount in the direction of the horizontal plane. Thus, by detecting the amount of displacement in the horizontal plane direction using one system of displacement sensor, the robot hand position can be corrected more inexpensively even when the target position up to a more detailed range is taught to the robot. It can be easily implemented with the configuration and taught.

  A robot hand according to a seventh aspect of the present invention includes an imaging unit that images a target mark provided with reference to a reference position set on a workpiece, and the imaging unit is configured to face the workpiece. The center of the target mark and the reference position of the imaging unit are arranged on the same axis.

  As a result, it is possible to recognize the relative positional deviation from the target position based on the target mark imaged by the imaging unit of the robot hand and to control the robot so that the positional deviation becomes small. Even when the target position is taught over a narrow range, the robot hand position correction can be performed easily and inexpensively.

  In the robot hand according to an eighth aspect of the present invention, a bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with the target position as a reference. The robot hand further includes a bush gripping portion that fits and grips the bush on a side facing the bush, and an inner peripheral surface of the bush gripping portion that contacts an outer periphery of the bush is formed in a tapered shape. It is a thing. Thereby, it is possible to more easily recognize the relative positional deviation between the robot hand and the target position, and to easily grip the bush.

  In a robot hand according to a ninth aspect of the present invention, a bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with the target position as a reference. The robot hand includes a bush holding portion that fits and holds the bush on a side facing the bush, a float portion that holds the bush holding portion and is movable in a horizontal plane, and the bush holding portion has the bush And a chuck portion that fixes the position of the bush gripping portion with respect to the bush when inserted. This makes it possible to clarify the positional relationship between the center of the robot hand and the center of the target mark of the bush by fixing the position of the bush holding part of the robot hand and the bush when the bush is inserted. it can.

  The robot hand according to a tenth aspect of the present invention is a robot hand further comprising a displacement amount detection unit that detects a displacement amount of the bush holding portion with respect to a reference position of the robot hand in the horizontal plane. As a result, even when the target position up to a more detailed range is taught to the robot, the position correction of the robot hand can be performed with high accuracy and ease.

  In the robot hand according to an eleventh aspect of the present invention, the deviation amount detection unit includes a displacement sensor that detects a displacement amount in a direction orthogonal to the horizontal plane, and a contact unit that is provided in the float unit and contacts the displacement sensor. The contact portion is formed such that the position of the contact point that contacts the displacement sensor changes according to the amount of movement of the float portion from a reference position in the horizontal plane, and the bush When the bush is gripped by the grip portion and the position of the bush grip portion relative to the bush is fixed by the chuck portion, the displacement amount by the displacement sensor is detected, and the detected displacement amount is determined in the direction of the horizontal plane. This is converted to the amount of deviation. Thus, by detecting the amount of displacement in the horizontal plane direction using one system of displacement sensor, even when teaching the target position to a more detailed range for the robot, the position correction of the robot hand is less expensive. It can be easily implemented with the configuration and taught.

  A robot according to a twelfth aspect of the present invention includes any one of the robot hands described above, a plurality of joints, and a control panel that controls driving of the joints. As a result, the relative positional deviation from the target position is recognized by the target mark imaged by the imaging unit of the robot hand, and the driving of the robot joint is controlled so that the positional deviation becomes small. When teaching the target position, the position correction of the robot hand can be easily and inexpensively performed.

  According to the present invention, the position of a robot hand capable of performing teaching from a wide range to a narrow range inexpensively and easily, and performing accurate teaching inexpensively and easily to perform good teaching. A correction method, a robot hand, and a robot can be provided.

1 is an overall configuration diagram schematically showing a robot according to a first embodiment. 1 is a diagram illustrating a configuration of a robot hand according to a first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of a bush holding portion according to Embodiment 1. 2 is a schematic diagram illustrating a configuration of a bush according to Embodiment 1. FIG. FIG. 3 is a front view showing the configuration of the robot hand according to the first embodiment. 2 is a cross-sectional view showing a configuration of a robot hand according to Embodiment 1. FIG. 2 is a cross-sectional view showing a configuration of a robot hand according to Embodiment 1. FIG. 6 is a schematic diagram for explaining an operation of a deviation amount detection unit according to Embodiment 1. FIG. 6 is a flowchart of position correction operation processing of the robot according to Embodiment 1. FIG.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. First, the overall configuration of the robot according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view schematically showing the overall configuration of the robot 100 according to the first embodiment.

  As shown in FIG. 1, the robot 100 includes a plurality of joints, links connected through the joints, a robot hand 300 provided at the tip, and a control panel (not shown). When the operator of the robot 100 operates the control panel, the actuator provided in each joint of the robot 100 is driven, and each joint is rotated. That is, the operator controls the position and posture of the robot hand 300 by operating the control panel.

  A global coordinate system is defined for the robot 100. For example, as shown in FIG. 1, a global coordinate system is defined in the X, Y, and Z axis directions with the base of the robot 100 as the origin, and the basic posture of the robot 100 is determined. A local coordinate system (not shown) is also defined for the robot hand 300. Based on these basic postures and coordinate system, control of each joint of the robot 100 and teaching of the target position of the robot hand 300 are performed.

  The operator teaches the robot 100 the target position when the robot hand 300 is working. The target position is set with respect to the workpiece 200 that is a target on which the robot 100 performs work. The workpiece 200 is installed at the work site of the robot 100. As will be described later, the robot 100 according to the first embodiment corrects the position of the robot hand 300 by controlling the joint driving of the robot 100 by the operator when teaching the robot 100 the target position. Do.

  Next, a detailed configuration of the robot hand 300 will be described with reference to FIGS. FIG. 2 is a configuration diagram when the robot hand 300 is viewed from below. The robot hand 300 includes a bush gripping part 310 and a float part 320. The robot hand 300 is attached to the distal end portion of the robot 100 via the attachment tool 101. The bush gripping part 310 grips the bush 210 provided in the workpiece 200. The float part 320 is configured to hold the bush gripping part 310 and be movable in a horizontal plane.

  FIG. 3 is a cross-sectional view showing the configuration of the bush gripping portion 310. The bush gripping part 310 includes a chuck part 312 and a CCD camera 313 as an imaging part. The CCD camera 313 is arranged so that the lens 314 is positioned at the center of the robot hand 300. The direction of the lens 314 is adjusted to the front direction of the robot hand 300. That is, the CCD camera 313 is arranged so as to capture an image of the bush 210 with the robot hand 300 facing the bush 210. An image picked up by the CCD camera 313 is displayed on a monitor (not shown). By disposing the CCD camera 313 in this way, the relative positional relationship between the bush 210 provided on the workpiece 200 and the robot hand 300 can be easily grasped by checking the monitor.

  Moreover, as shown in FIG. 3, the shape of the internal peripheral surface 311 of the bush holding | grip part 310 is formed in the taper shape. When the bush 210 is inserted into the bush gripping portion 310, the inner peripheral surface 311 of the bush gripping portion 310 abuts on the outer periphery of the bush 210. Therefore, the bush 210 can be easily inserted by configuring the shape of the inner peripheral surface 311 of the bush gripping portion 310 in this way.

  A target mark is provided on the side of the bush 210 on the side facing the robot hand 300. The target mark is provided based on the target position set on the workpiece 200. For example, as shown in FIG. 4, a stopper with a cross mark as a target mark is attached to the side surface of the bush 210. Here, the stopper is arranged so that the target position set for the workpiece 200 and the center position of the cross mark are located on the same axis. As a result, the operator confirms the positional relationship between the cross mark of the bush 210 imaged by the CCD camera 313 and the reference position of the monitor (for example, the cross mark set on the monitor). The relative positional deviation amount from the center of the bush 210 can be easily grasped.

  FIG. 5 is a front view showing the configuration of the robot hand 300. As shown in FIG. 5, a CCD camera 313 is arranged at the center of the robot hand 300. The CCD camera 313 can image the front of the robot hand 300. The chuck portion 312 includes chuck claws 312a, 312b, and 312c. The chuck portion 312 grips the bush 210 inserted into the bush grip portion 310 by opening and closing the chuck claws 312a, 312b, and 312c. Specifically, the chuck unit 312 controls the opening and closing of the chuck claws 312a, 312b, and 312c by controlling the air pressure of the air supplied to the chuck unit 312. 5 shows a state where the chuck claws 312a, 312b, 312c are opened, and the bush 210 has not yet been inserted into the bush gripping portion 310.

  The operator corrects the position of the robot hand 300 while confirming the image captured by the CCD camera 313 on the monitor outside the fence surrounding the work site of the robot 100. In other words, the operator moves the robot hand 300 closer to the workpiece 200 by correcting the position of the robot hand 300 from a wide range to a narrow range while checking the workpiece 200 displayed on the monitor. Further, the operator corrects the position of the robot hand 300 so that the projected cross mark of the bush 210 overlaps the reference position of the monitor while checking the cross mark of the bush 210 on the monitor.

  Then, the operator controls the drive of the joint of the robot 100 to cause the bush gripping portion 310 to grip the bush 210. Specifically, the bush 210 is inserted into the bush grip 310 by pressing the bush grip 310 of the robot hand 300 against the bush 210. Then, the position of the bush holding portion 310 is fixed with respect to the bush 210 by holding the bush 210 by the chuck portion 312. Thereby, the robot hand 300 fits and holds the bush 210 in the bush holding portion 310.

  FIG. 6 is a cross-sectional view showing a configuration of the robot hand 300 in a state where the bush 210 is gripped. In FIG. 6, a bush 210 is inserted into the workpiece 200 in advance, and the bush 210 is fixed at a predetermined position of the workpiece 200. For example, the bush 210 is inserted into the recess of the workpiece 200. The bush 210 is gripped by the bush gripping portion 310 when the chuck portion 312 is closed.

  Here, the configuration of the robot hand 300 will be described in more detail with reference to FIG. In FIG. 7, the float unit 320 is indicated by hatching with dots, and the shift amount detection unit 330 is indicated by hatching with diagonal lines.

  The float part 320 holds the bush gripping part 310. In addition, the float unit 320 is configured to be movable in a horizontal plane while holding the bush gripping unit 310. The float unit 320 is attached to the robot hand 300 so that the moving direction is horizontal. The float part 320 holds the bush gripping part 310 and moves only in the horizontal direction (vertical direction in the figure) with respect to the external force applied to the bush gripping part 310, and moves in the vertical direction (left and right direction in the figure). do not do. The float unit 320 is smoothly moved at the base by the ball, and the movement of the float unit 320 is restricted by controlling the air pressure of the supplied air. Accordingly, when the bush 210 is inserted into the bush gripping portion 310, the float portion 320 can be moved in the horizontal plane, and can be inserted while absorbing the amount of deviation. Further, by allowing the bush 210 to move in the horizontal plane with the bush 210 held by the bush gripping portion 310, the positional relationship between the central portion of the robot hand 300 and the target position of the workpiece 200 can be further clarified.

  The displacement amount detection unit 330 detects the displacement amount of the bush gripping unit 310 with respect to the reference position of the robot hand 300 in the horizontal plane in which the float unit 320 moves. The deviation amount detection unit 330 includes a displacement sensor 340 and a contact unit 321.

  The displacement sensor 340 detects the amount of displacement in the direction perpendicular to the horizontal plane direction with respect to the horizontal plane direction in which the float unit 320 can move. The displacement sensor 340 is disposed on the same axis as the center of the robot hand 300 in a direction orthogonal to the horizontal plane of the float unit 320.

  The contact part 321 is formed on the side surface of the float part 320 and contacts the displacement sensor 340. The contact portion 321 changes the position of the contact point that contacts the displacement sensor 340 in accordance with the amount of movement of the float unit 320 from a predetermined reference position (here, the center portion of the robot hand 300) in the horizontal plane. It is formed as follows. Here, the contact portion 321 is formed to have a predetermined inclination angle. In the example shown in FIG. 7, the contact portion 321 protrudes toward the displacement sensor 340 and is formed in a mountain shape. According to such a configuration of the contact portion 321 and the displacement sensor 340, the amount of deviation in the horizontal plane can be detected by the amount of displacement in the direction orthogonal to the horizontal plane.

  With reference to FIG. 8, the displacement amount detection method by the displacement amount detection unit 330 will be described in detail. FIG. 8 is a schematic diagram for explaining a deviation amount detection method by the deviation amount detection unit 330. When the bush 210 is inserted into the bush gripping portion 310 and the position of the bush gripping portion 310 relative to the bush 210 is fixed by the chuck portion 312, the displacement amount detection unit 330 detects the displacement amount by the displacement sensor 340, and The detected displacement amount is converted into a displacement amount in the direction of the horizontal plane.

  Specifically, as shown in FIG. 8A, when the center of the robot hand 300 is located on the same axis with respect to the target position set for the workpiece 200, the contact portion 321 and the displacement sensor 340 are disposed. Are in contact with each other on the same axis. That is, when the float unit 320 is located at the reference position of the float unit 320 (here, the center of the robot hand 300), the detection amount of the displacement sensor 340 is the smallest value within a predetermined detection range. (E.g., 0 is detected as a value).

  On the other hand, as shown in FIG. 8B, when the center of the robot hand 300 is not located on the same axis with respect to the target position set for the workpiece 200, the contact portion 321 and the displacement sensor 340 are Do not touch each other on the same axis. That is, when the float unit 320 is positioned away from the reference position of the float unit 320 (here, the center of the robot hand 300), the displacement sensor 340 is displaced toward the float unit 320, and a predetermined detection range is detected. Among them, a value corresponding to the amount of displacement is detected.

  The deviation amount detection unit 330 detects the deviation amount in the horizontal plane direction by converting the displacement amount detected by the displacement sensor 340 based on the inclination angle of the contact portion 321 with respect to the horizontal plane. As a result, the position of the robot hand 300 can be further corrected even when the target position up to a more detailed range is taught to the robot 100 by detecting the amount of deviation in the horizontal plane direction using one system of displacement sensor. It can be easily implemented and taught with an inexpensive configuration. The displacement amount detection unit 330 detects the displacement amount by displaying the detection amount by the displacement sensor 340 on a display counter (not shown), and the amount of displacement in the horizontal plane direction based on the displacement amount detected by the operator. May be calculated.

  Subsequently, the position correction operation of the robot hand 300 according to the first embodiment will be described. FIG. 9 is a flowchart for explaining the operation of correcting the position of the robot hand 300.

  First, the operator images the bush 210 with the CCD camera 313, and recognizes the relative positional deviation between the robot hand 300 and the bush 210 from the relationship between the captured target mark of the bush 210 and the reference position of the monitor ( Step S101). Then, the driving of the joint of the robot 100 is controlled so that the recognized positional deviation is small, and the position of the robot hand 300 is corrected from a wide range to a narrow range (step S102).

  Next, after the robot hand 300 is positioned in the vicinity of the workpiece 200, the bush holding portion 310 is pressed against the bush 210 and inserted, and the position of the bush holding portion 310 with respect to the bush 210 is fixed by the chuck portion 312 (step). S103).

  Next, the displacement amount detection unit 330 detects the displacement amount of the float unit 320 in the horizontal plane with respect to the reference position of the robot hand 300 (step S104). Then, the driving of the joints of the robot 100 is controlled so that the detected deviation amount is small, and the position of the robot hand 300 is corrected in a detailed range (step S105).

  As described above, according to the present invention, the target mark of the bush 210 is imaged by the CCD camera 313 mounted at the center of the robot hand 300, and the position relative to the target position of the workpiece 200 is captured by the captured target mark. Recognize the deviation. Then, by controlling the driving of the robot joints so that the positional deviation is small, even when the target position is taught from a wide range to a narrow range with respect to the robot 100, the position correction of the robot hand 300 is inexpensive and easy. Can be used to teach.

  Further, according to the present invention, when the bush 210 is inserted into the bush holding part 310, the float part 320 is moved in the horizontal plane, and when the bush 210 is used, the bush 210 with respect to the bush holding part 310 by the chuck part 312. The position of is fixed. Then, in a state where the bush gripping part 310 is fixed to the bushing 210, the target position up to a more detailed range with respect to the robot 100 is detected by detecting the amount of displacement in the horizontal plane direction using one system of displacement sensor. Even in the case of teaching, it is possible to easily perform the position correction of the robot hand 300 with a less expensive configuration.

Other Embodiments In the above-described first embodiment, the CCD camera 313 is described as being provided at the center of the robot hand 300, but the present invention is not limited to this. For example, the CCD camera 313 may be provided on the side surface of the robot hand 300. In this case, the target mark of the bush 210 cannot be captured in front of the CCD camera 313 by setting a predetermined offset at the reference position in the image captured by the CCD camera 313. Even so, the positional relationship between the bush 210 and the robot hand 300 can be accurately grasped. The predetermined offset can be set in consideration of the direction of the lens 314 of the CCD camera 313 with the robot hand 300 facing the bush 210.

  In the above-described first embodiment, the target mark of the bush 210 has been described using the single cross mark arranged at the center of the stopper provided in the bush 210 as shown in FIG. 4 as the target mark. It is not limited to. For example, cross marks may be arranged at the four corners of the stopper of the bush 210, respectively. In other words, the target mark may be any mark that can be imaged by the CCD camera 313 and the amount of deviation can be identified.

  Furthermore, in the first embodiment described above, the displacement sensor 340 is assumed to be disposed on the same axis as the center of the robot hand 300 in a direction orthogonal to the horizontal plane to which the float unit 320 is movable. Although described, the present invention is not limited to this. For example, it is good also as what arrange | positions in another position by considering the offset with respect to the contact part 313, and a phase.

  In addition, this invention is not limited to each embodiment mentioned above, In the range which does not deviate from the meaning, it can change suitably. For example, in the above-described embodiment, a CCD camera is described as an example of the imaging unit, but the present invention is not limited to this. That is, a CMOS sensor or a line sensor camera may be used.

100 robots,
101 fittings,
200 works,
210 bush,
300 robot hand,
310 Bush gripping part,
311 inner surface,
312 chuck part,
312a, 312b, 313c chuck claw,
313 CCD camera,
314 lenses,
320 float part,
321 contact portion,
340 Displacement sensor

Claims (12)

A method for correcting the position of the robot hand when teaching a target position set for a workpiece to a robot having a plurality of joints and a robot hand having an imaging unit,
The target mark provided with the target position as a reference is imaged by the imaging unit, and the relative position between the robot hand and the target position is determined from the captured target mark and the reference position of the imaging range of the imaging unit. A recognition step for recognizing misalignment;
A first position correction step of correcting the position of the robot hand by controlling the driving of the joints of the robot so that the recognized positional deviation is reduced. A bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with reference to the target position,
The center of the target mark and the reference position of the imaging unit in the state where the robot hand is moved to the target position and is opposed to the workpiece in the central part on the side facing the target mark. Are provided on the same axis, the imaging unit is provided,
The first position correction step includes:
The position correction method according to claim 1, wherein the position of the robot hand is corrected by controlling driving of the joint of the robot so that a center of the target mark and a reference position of the imaging unit overlap. . The robot hand is provided with a bush holding portion for fitting and holding the bush on the side facing the bush,
The inner peripheral surface of the bush grip portion with which the outer periphery of the bush abuts is formed in a tapered shape,
The position correction method according to claim 2, further comprising a bush gripping step for controlling the driving of the joint of the robot to cause the bush gripping portion to grip the bush. A bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with reference to the target position,
The robot hand is provided with a bush holding portion that fits and holds the bush on the side facing the bush, and a float portion that holds the bush holding portion and is movable in a horizontal plane. ,
The position correction method according to claim 1, further comprising: a bush gripping step that fixes a position of the bush gripper with respect to the bush when the bush is inserted into the bush gripper. The robot hand includes a displacement amount detection unit that detects a displacement amount of the bush holding portion with respect to a reference position of the robot hand in the horizontal plane,
A deviation amount detecting step of detecting the deviation amount in the horizontal plane by the deviation amount detection unit when the bush is held by the bush holding portion and the position of the bush holding portion relative to the bush is fixed by the chuck portion. When,
The position according to claim 4, further comprising: a second position correction step of correcting the position of the robot hand by controlling driving of the joint of the robot so that the detected amount of deviation is small. Correction method. The deviation amount detection unit
A displacement sensor that is provided in the robot hand and detects a displacement amount in a direction perpendicular to the horizontal plane;
A contact portion provided in the float portion and in contact with the displacement sensor,
The contact portion is formed such that a position of a contact point that contacts the displacement sensor changes according to a movement amount of the float portion from a reference position in the horizontal plane.
The deviation detection step includes
When the bush is gripped by the bush gripping portion and the position of the bush gripping portion with respect to the bush is fixed by the chuck portion, a displacement amount by the displacement sensor is detected, and the detected displacement amount is converted into the horizontal plane. The position correction method according to claim 5, wherein the positional correction amount is converted into a shift amount in a direction. An imaging unit that images a target mark provided with reference to a reference position set on a workpiece,
The imaging unit
A robot hand, wherein the center of the target mark and the reference position of the imaging unit are positioned on the same axis when facing the workpiece. A bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with the target position as a reference,
The robot hand is
A bush holding portion for fitting and holding the bush on the side facing the bush;
The inner peripheral surface of the bush grip portion with which the outer periphery of the bush abuts is formed in a tapered shape,
The robot hand according to claim 7. A bush is inserted into the workpiece, and the bush is provided with the target mark on the side facing the robot hand with the target position as a reference,
The robot hand is
A bush gripping part for fitting and gripping the bush on the side facing the bush;
A float part that holds the bush gripping part and is movable in a horizontal plane;
The robot hand according to claim 7, further comprising: a chuck portion that fixes a position of the bush gripping portion with respect to the bush when the bush is inserted into the bush gripping portion. The robot hand is
The robot hand according to claim 9, further comprising a displacement amount detection unit that detects a displacement amount of the bush holding portion with respect to a reference position of the robot hand in the horizontal plane. The deviation amount detection unit
A displacement sensor for detecting a displacement amount in a direction perpendicular to the horizontal plane;
A contact portion provided in the float portion and in contact with the displacement sensor,
The contact portion is formed such that a position of a contact point that contacts the displacement sensor changes according to a movement amount of the float portion from a reference position in the horizontal plane.
When the bush is gripped by the bush gripping portion and the position of the bush gripping portion with respect to the bush is fixed by the chuck portion, a displacement amount by the displacement sensor is detected, and the detected displacement amount is converted into the horizontal plane. The robot hand according to claim 10, wherein the robot hand is converted into an amount of deviation in the direction. The robot hand according to any one of claims 7 to 11,
Multiple joints,
And a control panel for controlling the driving of the joint.

Images