JP5892168B2 - Robot system - Google Patents

Description

  The present invention relates to a robot system.

  The control technology of industrial robots has progressed with the progress of computer technology, and in recent years, high-precision work by industrial robots has been required. For example, in an arc welding robot, a robot system is known in which a welding line is sensed to change the attitude of a welding torch before welding (see, for example, Patent Document 1). In the robot system of Patent Document 1, a sensor for sensing a welding line is provided integrally with the welding torch, and the attitude of the welding torch is controlled based on information sensed by the sensor.

JP-A-5-123866

  However, in the robot system described in Patent Document 1, sensing and work may not be performed continuously. For example, sensing and welding cannot be performed continuously at locations where the weld line is bent in the orthogonal direction. In this case, after performing welding to the end of one straight line, it is necessary to temporarily stop the welding and move the welding torch and sensor along the other straight line, which may reduce work efficiency. .

  The present invention has been made in view of the above problems, and an object thereof is to provide a robot system with improved work efficiency.

  A robot system according to the present invention includes a sensor unit, a sensor robot to which the sensor unit is attached, a working unit, and a working robot to which the working unit is attached.

  In one embodiment, the work robot changes at least one of a position and an orientation of the work unit based on information sensed by the sensor unit.

  In one embodiment, the position of the working unit is movable independently of the position of the sensor unit.

  In one embodiment, the robot system further includes a control unit that controls the sensor robot and the work robot.

  In one embodiment, the control unit temporarily stores information sensed by the sensor unit.

  In one embodiment, the control unit controls the work robot by performing coordinate conversion of information sensed by the sensor unit.

  In one embodiment, the working unit performs welding or sealing.

  In one embodiment, the sensor robot and the work robot move the sensor unit and the work unit in a predetermined direction at a constant speed.

  According to the present invention, it is possible to improve work efficiency in the robot system.

It is a mimetic diagram showing an embodiment of a robot system by the present invention. (A) And (b) is a typical top view for demonstrating the positional change of the sensor part and working part in the robot system of this embodiment. It is a typical side view of the robot system of this embodiment. It is a typical top view of the robot system of this embodiment. It is a schematic diagram of the robot system of this embodiment. It is a schematic diagram of the robot system of this embodiment. (A) And (b) is a typical side view for demonstrating the positional change of the sensor part and working part in the robot system of this embodiment. (A)-(d) is a typical side view for demonstrating the positional change of the sensor part in the robot system of this embodiment, and a working part. It is a typical conceptual diagram of the buffer used for the robot system of this embodiment. It is a typical perspective view of the robot system of this embodiment. It is a typical perspective view of the robot system of this embodiment. It is a typical perspective view of the robot system of this embodiment. It is a typical perspective view of the robot system of this embodiment.

  Hereinafter, an embodiment of a robot system according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

  In FIG. 1, the schematic diagram of the robot system 10 of this embodiment is shown. The robot system 10 includes a sensor unit 20, a sensor robot Rs to which the sensor unit 20 is attached, a work unit 30, and a work robot Rw to which the work unit 30 is attached. The robot system 10 performs work on the workpiece W.

  The sensor unit 20 senses the workpiece W. For example, the sensor unit 20 senses the surface state of the workpiece W. For example, a 2D laser sensor is used as the sensor unit 20. Or the sensor part 20 has an imaging part, and the imaging information of the surface of the workpiece | work W may be image-processed. Further, the sensor unit 20 may perform a follow-up search so as to follow a straight line formed at the boundary between two adjacent planes.

  The working unit 30 performs work on an area sensed by the sensor unit 20 in the workpiece W. For example, the working unit 30 performs welding. The working unit 30 that performs welding is also called a torch or a welding torch. Alternatively, the working unit 30 may apply a sealing agent to the workpiece W. Alternatively, the working unit 30 may be assembled (for example, screwed into a screw hole) or fitted.

  The work robot Rw can change at least one of the position and orientation of the work unit 30, thereby changing the posture of the work unit 30 with respect to the work W so as to improve the work accuracy. For example, after the sensor unit 20 senses a specific area of the workpiece W, the work robot Rw changes the position and / or orientation of the work unit 30 based on the information sensed by the sensor unit 20, and the work unit 30 Work on this area of W. As described above, the work robot Rw changes at least one of the position and orientation of the work unit 30, thereby suppressing the work position shift. In addition, the sensor robot Rs changes at least one of the position and orientation of the sensor unit 20, and thereby the sensor unit 20 can arbitrarily change the posture with respect to the workpiece W so as to increase the accuracy of sensing by the sensor unit 20. it can.

  The sensor robot Rs and the work robot Rw can operate independently so as not to collide with each other, and the position of the working unit 30 can be changed independently of the position of the sensor unit 20. For example, the sensor robot Rs may move the sensor unit 20 and the work robot Rw may move the work unit 30 so that the distance between the sensor unit 20 and the work unit 30 changes. Alternatively, the sensor robot Rs moves the sensor unit 20 and the work robot Rw moves the work unit 30 so that the distance between the sensor unit 20 and the work unit 30 does not change (that is, the distance becomes substantially constant). May be moved.

  As described above, since the sensor unit 20 and the working unit 30 are attached to different robots Rs and Rw, sensing and work can be performed at positions independent from each other, and work efficiency can be improved. In addition, since the sensor unit 20 and the working unit 30 can move independently, the working unit 30 can efficiently perform the work in a short time without interrupting the work.

  Note that sensing and work may be performed with the workpiece W fixed. For example, the sensor robot Rs and the work robot Rw may operate on the fixed workpiece W. Alternatively, the sensing and work may be performed while the work W is moved.

  Further, the robot system 10 may perform work on the work W on which work lines are formed. For example, the sensor unit 20 detects a work line, and the work unit 30 performs work along the work line based on information from the sensor unit 20.

  Hereinafter, the operation of the robot system 10 will be described with reference to FIG. Here, the work line Ws is formed by two straight lines extending in the x direction and the y direction, and the two straight lines intersect at an intersection Wo. Before the work unit 30 performs work along the work line Ws, the sensor unit 20 detects the work line Ws and senses position information of the work line Ws. Here, the sensor robot Rs and the work robot Rw move the positions of the sensor unit 20 and the work unit 30.

  As shown in FIG. 2A, after the sensor robot Rs moves the sensor unit 20 in the x direction along the work line Ws, the work robot Rw moves the work unit 30 along the work line so as to follow the sensor unit 20. Move in the x direction along Ws. In addition, it is preferable that the sensor unit 20 and the working unit 30 move at the same speed relative to the workpiece W. However, the moving speed of the working unit 30 may be different from the moving speed of the sensor unit 20. Thereafter, when the sensor unit 20 reaches the intersection Wo, the sensor robot Rs moves the sensor unit 20 in the y direction along the work line Ws.

  Thereafter, as shown in FIG. 2B, while the work robot Rw moves the work unit 30 in the x direction along the work line Ws, the sensor robot Rs moves the sensor unit 20 along the y direction. Let When the working unit 30 reaches the intersection Wo, the working robot Rw moves the working unit 30 in the y direction so as to follow the sensor unit 20.

  In the robot system 10, sensing and work can be continuously executed in the orthogonal direction without interruption. In addition, the work unit 30 can perform work continuously, so that work uniformity can be maintained. For example, when the working unit 30 performs welding, the welding state when the working unit 30 starts and / or interrupts welding may change compared to the welding state when welding is continuously performed. Alternatively, when the working unit 30 performs sealing, the amount of ejection of the sealing agent may change when the working unit 30 starts and / or interrupts the ejection of the sealing agent. On the other hand, in the robot system 10 of the present embodiment, the work unit 30 can keep the work uniformity by continuously performing the work without interruption. Note that when welding is performed on the workpiece W, the workpiece W may be distorted. However, by performing welding using the robot system 10, the distortion of the workpiece W can be reduced.

  In FIG. 2, work by the work unit 30 is started before the sensor unit 20 completes sensing of the work line Ws, and cooperative control of the sensor robot Rs and the work robot Rw is performed. The embodiment is not limited to this. After sensing by the sensor unit 20 is completed and the sensor robot Rs is stopped, the work by the working unit 30 may be started.

  In FIG. 2, the sensor robot Rs and the work robot Rw move the positions of the sensor unit 20 and the work unit 30, but the sensor robot Rs and the work robot Rw change the directions of the sensor unit 20 and the work unit 30, respectively. May be. However, it is preferable that the work robot Rw moves the work unit 30 so that the distance (shortest distance) between the work unit 30 and the work W is kept constant in order to achieve work uniformity.

  Typically, the sensor robot Rs and the work robot Rw are taught in advance so as to perform a predetermined operation, and the sensor robot Rs and the work robot Rw are based on the taught information. The position and orientation of the working unit 30 may be changed. Such work by the robot system 10 is also called copying work.

  In this case, the information sensed by the sensor unit 20 is used for fine adjustment of work. As a result of sensing, when correction is necessary, the work robot Rw changes the position or orientation of the work unit 30 with respect to the teaching operation. If it is not necessary to perform correction as a result of sensing, the work robot Rw does not have to change the position and orientation of the work unit 30 with respect to the teaching operation.

  Note that any robot may be used as the sensor robot Rs and the work robot Rw. However, at least one of the sensor robot Rs and the work robot Rw (particularly the work robot Rw) is preferably an articulated robot.

  FIG. 3 shows a schematic side view of the robot system 10 of the present embodiment, and FIG. 4 shows a schematic top view of the robot system 10. Here, the sensor robot Rs and the work robot Rw are both articulated robots. The sensor robot Rs is supported by the support member Ss, and the work robot Rw is supported by the support member Sw.

  For example, the work robot Rw is preferably a 6-axis or 7-axis articulated robot. Similarly, the sensor robot Rs is preferably a 6-axis or 7-axis joint robot. However, the sensor robot Rs may be a 3-axis or 4-axis joint robot. In addition, since the distance between the sensor unit 30 and the workpiece W may not be maintained constant, when the sensor robot Rs has joints of six axes or more, the sensor robot Rs has a redundancy degree of freedom. . For this reason, the sensor robot Rs may move so as to avoid surrounding obstacles when sensing by the sensor unit 20.

  The sensor robot Rs and the work robot Rw may move together with the support members Ss and Sw with respect to the fixed workpiece W. Alternatively, the workpiece W may move in a state where the support members Ss and Sw are fixed. Alternatively, both the support members Ss and Sw and the workpiece W may move.

  The operations of the sensor robot Rs and the work robot Rw are preferably controlled comprehensively.

  FIG. 5 shows a schematic diagram of the robot system 10 of the present embodiment. The robot system 10 illustrated in FIG. 5 includes a control unit 40 that controls the sensor robot Rs and the work robot Rw in addition to the sensor unit 20, the work unit 30, the sensor robot Rs, and the work robot Rw. Note that the control unit 40 may control the work robot Rw based on information sensed by the sensor unit 20. For example, the control unit 40 controls the work robot Rw by performing coordinate conversion of information sensed by the sensor unit 20. The control unit 40 may control work by the working unit 30 via a power source (not shown). The control unit 40 may be provided integrally with the sensor robot Rs or the work robot Rw.

  As shown in FIG. 6, the control unit 40 may include a robot substrate 42 and an external substrate 44. The robot substrate 42 is connected to the sensor robot Rs and the work robot Rw. The external substrate 44 is connected to the robot substrate 42 and the sensor unit 20. The external substrate 44 transmits the information sensed by the sensor unit 20 to the robot substrate 42, and the robot substrate 42 controls the work robot Rw so as to change at least one of the position and / or direction of the work unit 30. Although not shown here, the robot substrate 42 may have a communication substrate.

  As described above, when the sensor robot Rs and the work robot Rw move the sensor unit 20 and the work unit 30 independently, a region of the workpiece W sensed by the sensor unit 20 at a certain time is the work unit. 30 may be different from the area being worked on.

  Here, an example of positional changes of the sensor unit 20 and the working unit 30 in the robot system 10 will be described with reference to FIG. Here, for the purpose of preventing the drawing from becoming excessively complicated, the sensor robot Rs and the work robot Rw are omitted. However, as described above, the sensor unit 20 and the work unit 30 are provided with the sensor robot Rs and the work robot. Each is attached to the robot Rw. Here, attention is focused on the operation of the work W on the region R1.

  As shown in FIG. 7A, the sensor unit 20 and the working unit 30 each move in the x direction, and the sensor unit 20 senses the region R1 of the workpiece W at a certain time. Thereafter, the sensor unit 20 and the working unit 30 further move in the x direction.

  As shown in FIG. 7B, when the working unit 30 reaches the region R1 of the work W, the working unit 30 performs the work on the region R1 of the work W. In this case, the work robot Rw changes the position and / or orientation of the work unit 30 based on the information on the region R1 sensed by the sensor unit 20.

  Here, the region R1 of the workpiece W has been described. Similarly, in the other regions of the workpiece W, the time when the work unit 30 performs the work is different from the time sensed by the sensor unit 20, and thus the sensor unit 20 It is preferable to store at least temporarily information obtained by sensing each area of the workpiece W. For example, the control unit 40 (see FIGS. 5 and 6) may be used to store information obtained by sensing each area of the workpiece W by the sensor unit 20. In this case, the control unit 40 (for example, the external substrate 44 shown in FIG. 6) preferably has a delay buffer.

  When the work is performed along a straight line extending in one direction, it is preferable that the sensor robot Rs maintains the orientation of the sensor unit 20 and the work robot Rw maintains the orientation of the work unit 30. For example, both the sensor robot Rs and the work robot Rw point the sensor unit 20 and the work unit 30 directly below. In this state, when the sensor unit 20 and the working unit 30 move at a constant speed, the time from when the sensor unit 20 senses the region R1 to when the working unit 30 starts work in the region R1 is It is obtained by dividing the distance to the working unit 30 by the moving speed of the sensor unit 20 and the working unit 30. Thus, it is preferable that the control unit 40 reflects the work in consideration of the time lag.

  Hereinafter, an example in which sensing and work are performed from the start point to the end point of the work line will be described with reference to FIG. In FIG. 8, the start point of the work line is indicated as Wi, and the end point of the work line is indicated as Wo.

  As shown in FIG. 8A, first, the sensor robot Rs moves the sensor unit 20 to a position where the sensor unit 20 can sense the start point Wi.

  Next, as shown in FIG. 8B, while the sensor unit 20 senses the work line, the sensor unit 20 and the work unit 30 move at a constant speed, and the work robot Rw moves the work unit 30 to the start point Wi. Move to make initial adjustment. After that, sensing starts with work.

  As shown in FIG. 8C, the sensor unit 20 performs sensing, and the work performed by the working unit 30 is performed by reflecting the sensed information. Thereafter, as shown in FIG. 8D, even after the sensor unit 20 passes the end point Wo, the work is appropriately performed until the working unit 30 reaches the end point Wo.

  Here, an example of a method of processing the sensed position information will be described with reference to FIG. As described above, the position information sensed by the sensor unit 20 is stored in the buffer. For example, the position information (y0) in the y direction and the position information (z0) in the z direction sensed by the sensor unit 20 in the region R0 at the time t0 are stored in the buffer. Similarly, the position information (y1) in the y direction and the position information (z1) in the z direction sensed by the sensor unit 20 in the region R1 at the time t1 are stored in the buffer. Hereinafter, similarly, position information whose time and area are appropriately changed is stored.

  For example, the initial adjustment before starting the work is performed based on the sensed position information (y0) in the y direction and the position information (z0) in the z direction. On the other hand, the adjustment after starting the work is performed as follows.

  The control unit 40 acquires difference information from the position information. The difference information is obtained from the difference between the position information at a certain time and the position information at the immediately preceding time. For example, the control unit 40 acquires difference information (Δy1 = y1−y0) in the y direction from the position information y0 and y1 in the y direction at different times, and from the position information z0 and z1 in the z direction at different times, z Direction difference information (Δz1 = z1−z0) is acquired. Thereafter, when the work unit 30 performs work on the region R1, the control unit 40 controls the work robot Rw to change the position and / or orientation of the work unit 30 based on the difference information Δy1 and Δz1.

  For example, when the distance between the sensor unit 20 and the working unit 30 is 150 mm and the welding speed is 10 mm / second, the time from when a certain region is sensed by the sensor unit 20 until the work unit 30 performs the work. Is 15 seconds. For example, when the sensing period of the sensor unit 20 is 30 msec, the work robot Rw changes the position and / or orientation of the work unit 30 based on the position information of two places sensed about 500 places before.

  As described above, with reference to FIG. 7 to FIG. 9, the position change of the sensor unit 20 and the working unit 30 when the time when the working unit 30 performs the work for a certain area of the workpiece W is different from the time sensed by the sensor unit 20. Although the position information processing method has been described, the time at which work is performed by the work unit 30 in a certain area of the work W may be approximately equal to the time at which the sensor unit 20 senses. For example, the sensor robot Rs may adjust the position and orientation of the sensor unit 20 so that the sensor unit 20 faces a place where work is performed by the work unit 30 or a position immediately before work is performed by the work unit 30.

  In the above description, the sensor robot Rs and the work robot Rw are supported by different members, but the present embodiment is not limited to this. The sensor robot Rs and the work robot Rw may be supported by the same member. In the above description, the normal direction of the main surface of the workpiece W is arranged parallel to the vertical direction, but the present embodiment is not limited to this. The main surface of the workpiece W may be arranged parallel to the vertical direction.

  FIG. 10 is a schematic perspective view of the robot system 10 of the present embodiment. In the robot system 10 shown in FIG. 10, the sensor robot Rs and the work robot Rw are supported by the same support member S. For example, the support member S may be attached above (for example, the ceiling), and the sensor robot Rs and the work robot Rw may be arranged to be suspended.

  Note that both the sensor robot Rs and the work robot Rw may be movable along a predetermined direction.

  FIG. 11 shows a schematic perspective view of the robot system 10 of the present embodiment. In the robot system 10 shown in FIG. 11, the support unit Ss that supports the sensor robot Rs and the support unit Sw that supports the work robot Rw are moved in the direction D by an arbitrary method (for example, using a motor or the like). It can move along. As the support portions Ss and Sw move, the sensor robot Rs and the work robot Rw move along the direction D.

  In the above description, one sensor robot Rs to which the sensor unit 20 is attached and one work robot Rw to which the work unit 30 is attached are arranged for one workpiece W. It is not limited to.

  FIG. 12 is a schematic perspective view of the robot system 10 of the present embodiment. The robot system 10 shown in FIG. 12 has the same configuration as the robot system described above with reference to FIG. 11 except that a plurality of pairs of sensor robots Rs and work robots Rw are arranged. In order to avoid redundancy, redundant description is omitted. The robot system 10 illustrated in FIG. 12 includes a sensor robot Rsa to which the sensor unit 20a is attached, a work robot Rwa to which the work unit 30a is attached, a sensor robot Rsb to which the sensor unit 20b is attached, and a work unit 30b. The working robot Rwb is provided. The sensor robot Rsa and the work robot Rwa are supported by the support member Sa, and the sensor robot Rsb and the work robot Rwb are supported by the support member Sb. As described above, a plurality of pairs of sensor robots Rs and work robots Rw may be arranged.

  In the robot system 10 described above, the sensor robot Rs and the work robot Rw are configured as a pair, but the present embodiment is not limited to this. The number of sensor robots Rs may be different from the number of work robots Rw. For example, a plurality of sensor robots Rs may be arranged for one work robot Rw. Further, the workpiece W may be moved so as to facilitate sensing and / or work.

  FIG. 13 is a schematic perspective view of the robot system 10 of the present embodiment. The robot system 10 shown in FIG. 13 includes workpiece holding robots Hwa and Hwb that can hold a workpiece W (not shown in FIG. 13), a loading conveyor Ca that loads the workpiece W, and a loading conveyor that loads the workpiece W. The robot system has the same configuration as that of the robot system described above with reference to FIG. 12 except that Cb is further provided, and redundant description is omitted to avoid redundancy.

  When the carry-in conveyor Ca carries the workpiece W, the workpiece holding robots Hwa and Hwb hold the workpiece W in an arbitrary manner. The work holding robots Hwa and Hwb may move the work W during sensing and / or work as necessary. Further, if necessary, the workpiece holding robots Hwa and Hwb may perform sensing and / or work in a state where the workpiece W is curved. After the work is completed, the workpiece W is carried out by the carry-out conveyor Cb.

  According to the robot system of the present embodiment, work efficiency can be improved. For example, work time such as welding or sealing can be shortened and work quality can be improved.

DESCRIPTION OF SYMBOLS 10 Robot system 20 Sensor part 30 Working part 40 Control part Rs Sensor robot Rw Working robot

Claims (9)

A sensor unit;
A sensor robot to which the sensor unit is attached;
A working section;
A working robot with the working unit attached thereto,
When the work robot performs work on a work line of a workpiece,
The sensor robot moves the sensor unit along the work line,
The robot system, wherein the work robot moves the work part along the work line so as to follow the sensor part based on information obtained by sensing the work line by the sensor part of the sensor robot.   The robot system according to claim 1, wherein the position of the working unit is movable independently of the position of the sensor unit. Further comprising a robot system according to claim 1 or 2 a control unit for controlling the sensor robot and the work robot. The robot system according to claim 3 , wherein the control unit temporarily stores information sensed by the sensor unit. The robot system according to claim 3 or 4, wherein the control unit controls the work robot by performing coordinate conversion of information sensed by the sensor unit. The working unit carries out welding or sealing, the robot system according to any one of claims 1 to 5. Said sensor robot and the work robot, the causes the sensor unit and the working unit is moved at a constant speed in a predetermined direction, the robot system according to any one of claims 1 to 6.   A support member for supporting the sensor robot and the work robot;
  The robot system according to any one of claims 1 to 7, wherein each of the sensor robot and the work robot is an articulated robot arranged to be suspended from the support member.   A workpiece holding robot capable of holding the workpiece in an arbitrary manner;
  A carry-in conveyor for carrying the workpiece;
  An unloading conveyor for unloading the workpiece;
  The robot system according to claim 8, further comprising:

Images