JP5061965B2 - Robot production system - Google Patents

Description

  The present invention relates to a robot production system in which an installation operation for automatically teaching a position of a workpiece to a robot production system and installing the robot production system is automated.

  Conventionally, in order to assemble precision parts, a robot production system has been proposed in which a workpiece is gripped and moved, and this workpiece is assembled to another workpiece. In such a robot production system, it is necessary to accurately teach the hand position of the robot. That is, the robot production system needs to accurately teach the hand position on the premise that the robot production system is firmly fixed at a predetermined position and the workpiece is also accurately positioned at the predetermined position. This is because the work placed at a predetermined position cannot be gripped unless the hand position is correctly taught.

  As a technique for accurately performing such teaching, for example, Patent Document 1 discloses a part on a workpiece corresponding to at least one teaching point among teaching points for which position data is given on a teaching program. A mark that can be identified by the camera is applied to the camera, the position of the mark is measured by a camera mounted on the robot, and a three-dimensional correction amount of the position data of at least one teaching point is obtained based on the measurement result of the mark position. A method for obtaining a three-dimensional position correction amount of teaching position data to be obtained is described.

  Further, in Patent Document 2, in a robot, a plurality of workpieces and an assembly tool are used as objects to be loaded, and each of the objects to be loaded is carried from the outside of the movable range of the robot to the inside of the movable range. And the assembly tool after use as an object to be unloaded, and a transport means for unloading each unloaded object from the inside of the movable range to the outside of the movable range, so that the assembly tool can be replaced without relying on human hands. Thus, there is described an apparatus which can efficiently produce a variety of products in small quantities.

  In Patent Document 3, a 6-axis force sensor is provided on the wrist axis of a robot manipulator, and when a calibration point is taught using a robot system that performs impedance control, a jig having a circular hole is used as a fixed point. Prepare a rod that can be inserted into the circular hole of this jig as a tool and attach it to the wrist axis of the robot manipulator.The tip of this tool is the control point of the robot manipulator, and the robot's circular hole is inserted into the circular hole of the jig. It is described that a fixed point is observed by inserting a rod as a tool, and position information and posture information of a robot control point are used as calibration information.

Japanese Patent No. 3665353 Japanese Patent No. 3673117 JP-A-5-111886

  In conventional robot production systems, the work load on the site operator, such as workpiece positioning and teaching operations, is large. Especially, when the workpieces are diversified, the number of times of positioning and teaching increases. The problem is that the productivity of the entire automatic production work by the system is lowered.

  In the techniques described in Patent Documents 1 to 3 described above, dedicated jigs and assembly tools must be prepared or marked, and teaching work cannot be facilitated sufficiently. .

  Therefore, the present invention has been made in view of the above circumstances, and its purpose is to complete a highly accurate teaching work in a short time without the need to prepare a dedicated jig or tool, and to accurately Providing a robot production system that eliminates the need for precise alignment, facilitates installation work on the production line, and allows repositioning between the state installed on the production line and the state removed from the production line There is.

To solve the problems described above, to achieve the above object, the present invention has the following configuration.

[Configuration 1]
A robot production system according to the present invention is a robot production system having a robot arm having a gripping hand for gripping a workpiece and moving the workpiece to a predetermined position. And a misalignment detecting means for detecting the amount of misalignment of the position of the work table with respect to a predetermined position when the work table is installed, and teaching data as a reference for the operation of the robot arm based on the detection result by the misalignment detecting means The position deviation detecting means includes an image pickup means for detecting the position of the work based on an image obtained by imaging an area including the work, and a gripping hand toward the work. When the gripping hand and the workpiece come into contact with each other when moving and gripping the workpiece, the force applied to the gripping hand is detected. The position deviation correction means is a control means for controlling the robot arm according to the detection result by the imaging means, and performs a calculation based on the force detected by the force sensor and makes the gripping hand follow the workpiece. This is a calculation means for detecting the position of the work while being in close contact with the work. Based on the measurement result of the imaging means, the gripping hand is approached to the work, the work is gripped by the gripping hand, and the gripping hand comes into contact with the work. Detecting the force, making the gripping hand follow the workpiece and making it come into close contact with the workpiece, detecting the position of the workpiece, storing the detected workpiece position, and correcting the teaching data based on the stored workpiece position It is characterized by.

  In this robot production system, a position deviation detecting means for detecting a position deviation amount with respect to a predetermined position of the position of the work table, and teaching data serving as a reference for the operation of the robot arm are corrected based on a detection result by the position deviation detecting means. By providing the position deviation correction means, automation of position correction (teaching) by the robot production system was realized.

  Also, in this robot production system, even when a workpiece is transported by the work tray, the positional deviation between the robot production system and the work tray can be corrected, so that the same automation as when the workpiece is transported as it is is possible. It is.

  In this robot production system, it is possible to perform high-accuracy alignment by having an imaging unit as a positional deviation detection unit.

  Since the robot production system according to the present invention has the configuration 1, the position deviation detecting means for detecting the amount of position deviation of the position of the work table with respect to the predetermined position, and the operation of the robot arm based on the detection result by the position deviation detecting means. It is equipped with a position deviation correction means that corrects the teaching data used as a reference for the above, so that the position correction by the robot production system can be automated.

  In the robot production system according to the present invention, it is not necessary to accurately position the work table, so that the installation work on the production line is easy. Furthermore, this robot production system can change the arrangement between the state installed on the production line and the state removed from the production line. For example, in a production line in which a worker performs work during the day, the robot production system according to the present invention is installed on the production line at night so that it can be easily switched to fully automatic production. In addition, the robot production system can be installed in another line with a large production volume to adjust the operation. Furthermore, when the robot production system fails, the downtime can be minimized by removing the robot from the production line and switching to the work performed by the worker. Further, even when the layout of the production line is changed, the installation work of the robot production system on the production line is easy, so it can be easily handled.

  Further, in the present invention, since a dedicated jig for positioning the workpiece is not necessary, on the same assembly line as the worker, for example, on behalf of the worker during a time when the worker does not work. Automatic production can be carried out using the same jigs, tools, work tables and automatic devices that were used by the workers. That is, space can be saved by using the same line as a person, and equipment costs can be reduced.

  Since the robot production system according to the present invention has the configuration 2, the positional deviation detection means is an imaging means for detecting the position of the workpiece based on an image obtained by imaging an area including the workpiece. Since the correcting means is a control means for controlling the robot arm according to the detection result by the imaging means, highly accurate alignment is possible.

  That is, according to the present invention, it is not necessary to prepare a dedicated jig or tool, and high-precision teaching work can be completed in a short time, and accurate positioning is not required, and installation work on a production line is easy. Thus, it is possible to provide a robot production system capable of freely changing the arrangement between the state installed on the production line and the state removed from the production line.

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

[First Embodiment]
1 to 4 show a first embodiment of a robot production system according to the present invention, FIG. 1 is a schematic perspective view of the robot production system, FIG. 2 is a block diagram of the robot production system, and FIG. FIG. 4 is a schematic perspective view of the installation state of the robot production system.

  As shown in FIG. 1, the robot production system 1A includes first, second, and third work tables T1, T2, and T3 that can be repositioned and arranged at close positions, and the first, second, and second work tables. Three work bases 10, 10, 10 installed at predetermined positions on the three work tables T1, T2, T3, a work tray 20 that can be selectively placed on the three bases 10, 10, 10, A transfer robot 30 installed on one work table T1, and first, second, and third work robots installed on the first, second, and third work tables T1, T2, and T3, respectively, for performing predetermined work. R1, R2, and R3. Among these, the first work table T1 and the transfer robot 30 installed on the first work table T1 constitute a robot production system according to the present invention. Note that the robot production system according to the present invention may be configured without the first work robot R1.

  The transfer robot 30 includes a multi-joint arm unit 31 which is a hand moving unit whose lower end is fixed to the first work table T1, a gripping hand 32 attached to the tip of the multi-joint arm unit 31, and a gripping hand 32. And a camera 33 which is an image pickup unit constituting a misalignment detection unit fixed in the vicinity.

  As shown in FIG. 2, the multi-joint arm unit 31 swings and rotates each joint by a drive signal from the control unit 51 that constitutes the misalignment correction unit, thereby setting the position of the gripping hand 32 to a predetermined position. Move to. The image signal from the camera 33 is sent to the image processing unit 52 and further sent to the control unit 51. Further, the gripping hand 32 is attached with a force sensor 53 that constitutes a position deviation detecting means described later. An output signal from the force sensor 53 is sent to the control unit 51.

  In this robot production system, the control unit 51 is built in the first work table T1, and has an integral structure that can be transported together with the first work table T1. In this robot production system, since the image processing unit 52 is also built in the first work table T1, it can be used by connecting only the power line and the signal line to the external device.

  As shown in detail in FIG. 3, the gripping hand 32 includes a hand base portion 35 that is rotatably attached to the tip of the articulated arm portion 31, and a pair of hand pieces 36 provided below the hand base portion 35. 36. The pair of hand pieces 36, 36 includes an upper surface portion 36a that moves along the hand base portion 35, a side surface portion 36b that is suspended from the upper surface portion 36a, and a lower surface portion 36c that protrudes inward from the lower end of the side surface portion 36b. It consists of and. Guide tapered surfaces 37 are formed at both ends of each upper surface portion 36a.

  The pair of hand pieces 36, 36 can move in a direction to widen and narrow the distance between each other, and is positioned at a hand open position that allows entry into the grip 23 and a hand closed position that grips the grip 23. Can do.

  Image information of the position-recognizing visual marker 24 photographed by the camera 33 is sent to the control unit 51, and the control unit 51 controls driving of the articulated arm unit 31 based on the image information.

  The first to third work robots R1, R2, and R3 use the work holding positions of the work trays 20 placed on the pedestals 10, 10, and 10 of the work tables T1, T2, and T3 as work positions. Then, the first, second, and third work robots R1, R2, and R3 perform predetermined work on the work 40, respectively, at the taught work positions.

  The transfer robot 30 is provided with a force sensor 53. The force sensor 53 is obtained by the camera 33 when the transfer robot 30 moves toward the workpiece 40 placed on a work table other than the first work table T1 (second and third work tables T2, T3). When the workpiece 40 whose position has been detected based on the obtained image is to be gripped, the force received by the gripping hand 32 when the gripping hand 32 of the transfer robot 30 comes into contact with the workpiece 40 is detected. The force detected by the force sensor 53 is sent to the control means 51. The control means 51 performs calculation based on force, and detects the position of the workpiece 40 by bringing the gripping hand 32 into close contact with the workpiece 40 as shown in FIG.

  And the control apparatus 51 memorize | stores the position of the detected workpiece | work 40, and controls the conveyance robot 30 after this based on this memory | storage. That is, teaching to the transfer robot 30 is automatically performed. The transfer robot 30, the first, second, and third work robots R1, R2, and R3 are not vertical articulated robots, and may take any form such as a horizontal articulated robot or an orthogonal axis robot. The first, second, and third work robots R1, R2, and R3 are not limited to robots, and may take any form such as a processing machine, a screwing machine, or a caulking machine.

  FIG. 4 is a schematic perspective view of the installation state of the robot production system according to the present invention.

  This robot production system grips the work 40 placed on the first work table T1, moves it onto the second and third work tables T2 and T3, and moves the work placed on the respective work tables. It is possible to perform a predetermined operation on the. At this time, since the teaching based on the image obtained by the camera 33 and the force detected by the force sensor 53 is performed prior to the work, the first work in which the transport robot 30 is placed and fixed as shown in FIG. The position of the table T1 does not need to be accurately installed. In FIG. 4, the position of the first work table T <b> 1 is an accurate position indicated by the alternate long and short dash line, and the position indicated by the solid line indicates a misaligned state.

  Therefore, the robot production system can freely change the arrangement between the state installed on the production line and the state removed from the production line. For example, in a production line in which a worker performs work during the day, the robot production system according to the present invention is installed on the production line at night so that it can be easily switched to fully automatic production. That is, prior to starting full-automatic production, by performing the teaching as described above, the workpiece 40 placed on the first work table T1 can be accurately grasped and other work tables (second and second work tables) can be obtained. (3 work tables T2, T3,...) Can be moved to a predetermined position, and placed on other work tables (second and third work tables T2, T3,...). The workpiece 40 can be accurately gripped and moved to a predetermined position on the first work table T1.

  Further, even when the layout of the production line is changed, the installation work of the robot production system on the production line is easy, so it can be easily handled. Furthermore, in this robot production system, since it is easy to change with the worker, it is possible to smoothly cope with cell production. In addition, the robot production system can be installed in another line with a large production volume to adjust the operation. Furthermore, when the robot production system fails, the downtime can be minimized by removing the robot from the production line and switching to the work performed by the worker.

  FIG. 5 is a flowchart showing a procedure for detecting the position of the workpiece 40 in this robot production system.

  The robot production system according to the present invention configured as described above detects the position of the workpiece 40 and automatically performs a teaching operation as shown in FIG. That is, as shown in FIG. 5, when the control unit 51 starts an operation in S11, the control unit 51 proceeds to S12 and starts measuring the position of the workpiece 40 based on the image data obtained by the camera 33 (position shift). detection). Next, in S <b> 13, the gripping hand 32 of the transfer robot 30 is approached toward the work 40 based on the measurement result.

  Then, the process proceeds to S 14, where the workpiece 40 is gripped by the gripping hand 32 of the transfer robot 30, the force received by the gripping hand 32 coming into contact with the workpiece 40 is detected, and the gripping hand 32 follows the workpiece 40 and closely contacts the workpiece 40. Thus, the position of the workpiece 40 is accurately detected (position shift detection). Next, in S15, the detected position of the workpiece 40 is stored.

  Proceeding to S16, the teaching data is corrected based on the stored position of the workpiece 40 (positional deviation correction). By this correction, automatic teaching is performed. Then, the process proceeds to S17 and the automatic teaching is finished. Thereafter, the control unit 51 controls the transport robot 30 based on the corrected teaching data.

  FIG. 6 is a flowchart showing an operation method of this robot production system.

  As described above, the robot production system according to the present invention configured as described above is installed and used in a production line where work is normally performed by an operator as shown in FIG. Can be provided.

  That is, as shown in FIG. 6, when the operation of the robot production system is started in S21, the process proceeds to S22, and this robot production system is arranged on the production line where the work of the worker is completed as a substitute for the worker. . In S23, the control unit 51 automatically corrects the positional deviation between the first work table T1 and the production line according to the teaching data correction procedure shown in FIG. Here, the production line may be the second and third work tables T2 and T3 described above, or may be another work table or another line of the same form. Then, the process proceeds to S24, and automatic production by the robot production system is started. That is, space can be saved by using the same line as a person, and equipment costs can be reduced.

  When the automatic production is finished in S25, the process proceeds to S26, where the robot production system is removed from the production line and carried out. At this time, it becomes a state where the work by a normal worker can be started. Then, the process proceeds to S27, and the operation of the robot production system is terminated.

[Second Embodiment]
FIG. 7 is a schematic plan view of a robot production system according to the second embodiment of the present invention.

  The positional deviation detection means in the robot production system of the present invention is not limited to means for detecting the relative position between the workpiece 40 and the transfer robot 30, such as the camera 33 (imaging means) and the force sensor 53 in the above-described embodiment. 7, means for detecting a relative position between the first work table T1 and work tables other than the first work table T1 (second and third work tables T2, T3). There may be.

  As such a detection means, for example, a plurality of laser distance meters 55 installed on the first work table T1 can be used. That is, by these laser distance meters 55, between the first work table T1 and other work tables (second and third work tables T2, T3,...) Or a wall or other position reference object. By measuring the relative position / orientation, it is possible to detect the amount of displacement with respect to the reference position of the first work table T1. Automatic teaching can be performed by correcting the teaching data by the control unit 51 based on the detected positional deviation amount. Then, the control unit 51 controls the transport robot 30 based on the corrected teaching data.

  Also in the robot production system in this embodiment, the arrangement can be freely changed between the state installed on the production line and the state removed from the production line. Prior to starting full-automatic production, the work 40 placed on the first work table T1 is accurately grasped by performing the teaching as described above, so that other work tables (second and third work) can be obtained. Can be moved to a predetermined position on the tables T2, T3,..., And can be placed on other work tables (second and third work tables T2, T3,...). 40 can be accurately gripped and moved to a predetermined position on the first work table T1.

  Further, even when the layout of the production line is changed, the installation work of the robot production system on the production line is easy, so it can be easily handled. Furthermore, in this robot production system, since it is easy to change with the worker, it is possible to smoothly cope with cell production.

1 is a schematic perspective view of a robot production system according to a first embodiment of the present invention. 1 is a block diagram of a robot production system according to the present invention. It is a perspective view of the holding hand and camera of a conveyance robot. It is a schematic perspective view of the installation state of the robot production system concerning the present invention. 5 is a flowchart showing a procedure for specifying a position of a workpiece in the robot production system according to the present invention. It is a flowchart which shows the operation method in the robot production system which concerns on this invention. It is a schematic plan view of the robot production system in the 2nd Embodiment of this invention.

Explanation of symbols

30 transfer robot T1 first work table 33 camera 40 work 51 control means 53 force sensor 55 laser distance meter

Claims (1)

In a robot production system having a robot arm with a gripping hand for gripping a workpiece and moving the workpiece to a predetermined position,
A work table with the robot arm disposed thereon and freely changeable arrangement;
A positional deviation detecting means for detecting a positional deviation amount of the position of the work table with respect to a predetermined position when the work table is installed;
A position deviation correction means for correcting teaching data serving as a reference for the operation of the robot arm based on a detection result by the position deviation detection means ;
The positional deviation detection means picks up an image of the area including the work, and based on the obtained image, the image pickup means for detecting the position of the work, and the gripping hand moves toward the work, A force sensor for detecting a force received by the gripping hand when the gripping hand and the workpiece contact when trying to grip a workpiece;
The misregistration correction unit performs control based on a force detected by the force sensor and a control unit that controls the robot arm according to a detection result by the imaging unit, and causes the gripping hand to follow the workpiece. Calculating means for detecting the position of the work in close contact with the work,
Based on the measurement result of the imaging means, the gripping hand is approached toward the work, the work is gripped by the gripping hand, and the force received by the gripping hand coming into contact with the work is detected. The position of the workpiece is detected by closely contacting the workpiece, and the detected position of the workpiece is stored, and the teaching data is corrected based on the stored position of the workpiece. Characteristic robot production system.

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