Robot

A robot configured to perform a work to a moving workpiece is provided, which includes a first robotic arm provided at a tip end thereof with a guide tool configured to support the workpiece, a second robotic arm provided at a tip end thereof with a work tool configured to perform a specific work to the workpiece, and a control device configured to control operations of the first and second robotic arms. The control device controls the operations of the first and second robotic arms according to timing information for which the workpiece reaches a workspace of the robot so that the guide tool guides the workpiece located in the workspace into the space and the work tool performs the specific work to the workpiece guided into the space.

TECHNICAL FIELD

The present disclosure relates to a robot.

BACKGROUND ART

In recent years, in terms of improving productivity, it has been proposed that a robot performs a work which is similar to a work conventionally performed by a human in a manufacturing site, such as a factory. For example, Patent Document 1 discloses a robot which performs works, such as gripping an object, moving the gripped object, and combining a plurality of objects. Patent Document 2 discloses a robot which performs a work to handle a workpiece by using a 3D camera (bin-picking). Patent Document 3 discloses a robot which performs a work to change the way the robot holds a workpiece by using a hand and a contact sensor for the workpiece. Moreover, Patent Document 4 discloses a robot which performs an assembly work (fitting etc.) of a flexible object by using a camera and a force sensor.

REFERENCE DOCUMENTS OF CONVENTIONAL ART

Patent Documents

DESCRIPTION OF THE DISCLOSURE

Problems to be Solved by the Disclosure

However, the conventional robots described above all assume the work for the stationary workpiece. Thus, in order to perform a specific work to the workpiece which is moving on a conveyor etc., a tracking control etc. for recognizing the position of the moving workpiece is additionally required, resulting in a complicated structure of the system.

The present disclosure is made in order to solve the problems described above, and one purpose thereof is to realize a robot which is capable of performing a specific work to a moving workpiece, with a comparatively simple structure.

Summary of the Disclosure

In order to achieve the purpose, a robot according to one aspect of the present disclosure is a robot configured to perform a work to a moving workpiece, which includes a first robotic arm provided at a tip end thereof with a guide tool configured to support the workpiece, a second robotic arm provided at a tip end thereof with a work tool configured to perform a specific work to the workpiece, and a control device configured to control operations of the first and second robotic arms. The control device controls the operations of the first and second robotic arms according to timing information for which the workpiece reaches a workspace of the robot so that the guide tool guides the workpiece located in the workspace into the space and the work tool performs the specific work to the workpiece guided into the space.

According to this configuration, the workpiece located in the workspace is guided into the workspace by the guide tool provided to the tip end of the first robotic arm, according to the timing information for which the moving workpiece reaches the workspace of the robot, and the work is performed to the workpiece guided into the workspace by the work tool provided to the tip end of the second robotic arm. Thus, the work can be performed to the moving workpiece according to the timing information, without performing a tracking control etc. of the workpiece.

The robot may further include a detecting means for detecting a timing at which the workpiece reaches the workspace of the robot and outputting a detection signal to the control device.

According to this configuration, the timing at which the workpiece reaches the workspace of the robot can correctly be calculated. For example, the timing at which the workpiece reaches may be detected by a photoelectric sensor provided near a conveyor which conveys the workpiece, or the timing information may be calculated by analyzing an image of a fixedly-installed camera.

The robot may further include a contact sensor configured to detect that the guide tool contacts the workpiece and output a detection signal to the control device. The control device may control the operation of the second robotic arm so that the work tool performs the specific work to the workpiece when the detection signal is received from the contact sensor.

The first robotic arm may be configured to regulate a movement of the workpiece in a conveying direction of the conveyor and maintain the workpiece in a given posture, by the guide tool performing operation to guide the workpiece being conveyed on the conveyor in a given direction in width directions of the conveyor. The second robotic arm may be configured to perform a work to supply a given object to the workpiece that became in the given posture.

The robot may further include a regulating member configured to stop within the workspace the workpiece located in the workspace. The first robotic arm may support one side surface of the workpiece located in the workspace by the guide tool and guide another side surface of the workpiece toward the regulating member.

According to this configuration, it becomes easy to maintain the workpiece in the given posture, by supporting the one side surface of the workpiece located in the workspace by the guide tool, and guiding the another side surface of the workpiece toward the regulating member.

Effect of the Disclosure

The present disclosure can realize the robot which is capable of performing the specific work to the moving workpiece, with the comparatively simple structure.

MODES FOR CARRYING OUT THE DISCLOSURE

Hereinafter, preferable embodiments will be described with reference to the drawings. Note that, below, the same referential characters are given to the same or corresponding elements throughout the drawings to omit redundant description. Moreover, in order to make them easy to understand, the drawings are to schematically illustrate each component, and the shape, a dimension ratio, etc. may not be illustrated correctly.

First Embodiment

A robot according to a first embodiment is, for example, used at a food factory which produces box lunch (bento) etc. Moreover, although in this embodiment a case where a horizontal articulated type dual-arm robot is used as one example of the robot will be described, an articulated robot having a plurality of robotic arms can be used, regardless of the horizontal articulated type or a vertical articulated type.

[One Example of Structure of Robot]

FIG. 1is a front view illustrating the entire structure of one example of the robot according to the first embodiment, andFIG. 2is the schematic plan view. As illustrated inFIGS. 1 and 2, a robot1includes a carrier17, a pair of robotic arms (hereinafter, simply referred to as “the arm(s)”)10supported by the carrier17, and a control device6accommodated in the carrier17.

This robot1is a dual-arm robot having left and right arms10. The left and right arms10are capable of operating independently, and are capable of operating in a mutually-related manner.

Each arm10is a horizontal articulated type robotic arm, and includes an arm part11, a wrist part13, and a hand part15. In this example, the arm part11is comprised of a first link12aand a second link12b. Moreover, the hand part15is comprised of a tool5, and the wrist part13has a mechanical interface to which the tool5is attached. Note that the left and right arms10have substantially the same structure except for the hand parts15, and the tools5of the left and right hand parts15may have the same structure or may have different structures.

The first link12aof the arm part11is coupled to a base shaft16fixed to an upper surface of the carrier17by a revolute joint. The first link12ais rotatable on a vertical rotational axis L1passing through the axial center of the base shaft16. Moreover, the second link12bis coupled to a tip end of the first link12aby a revolute joint. The second link12bis rotatable on a vertical rotational axis L2defined at the tip end of the first link12a.

The wrist part13is coupled to a tip end of the second link12bby a prismatic joint, and is movable upward and downward with respect to the second link12b.

The tool5of the hand part15is coupled to the wrist part13by a revolute joint, and is rotatable on a vertical rotational axis.

Each arm10of the structure described above has joint axes J1-J4corresponding to the respective joints. The arm10is provided with driving servo motors (not illustrated) and encoders (not illustrated) which detect rotational angles of the servo motors, so that they are associated with the joint axes J1-J4, respectively.

The rotational axes L1of the first links12aof the two arms10of the structure described above are on the same straight line, and the first link12aof one arm10and the first link12aof the other arm10are disposed with a vertical height difference. The origin of a basic coordinate system of the robot1is defined on the rotational axis L1of the first link12a.

Next, the control device6is described.FIG. 3is a block diagram illustrating an outline configuration of the control device6. As illustrated inFIG. 3, the control device6includes an operation part601such as a CPU, a memory part602, such as a ROM and/or a RAM, a servo control part603, and an interface part604. The control device6is a robot controller provided with, for example, a computer, such as a microcontroller. Note that the control device6may be comprised of a single control device which carries out a centralized control, or may be comprised of a plurality of control devices which carry out a distributed control in which the control devices collaborate mutually.

The memory part602stores information, such as a basic program as a robot controller, various fixed data, etc.

The operation part601controls various operations of the robot1by reading and executing software, such as the basic program stored in the memory part602. That is, the operation part601generates a control instruction of the robot1, and outputs this to the servo control part603. The servo control part603is configured to control the drive of the servo motors corresponding to the joint axes J1-J4of each arm10of the robot1based on the control instruction generated by the operation part601.

The interface part604is communicatably connected with a timing information detecting means7, and outputs a detection signal acquired from the timing information detecting means7to the operation part601.

Moreover, if the tool5of the hand part15is configured to perform operation of a chuck, adsorption, etc., the control of the operation is also performed by the control device6. Further, if the tool5chucks another tool and this another tool performs the operation of the chuck, adsorption, etc., the control of the operation of another tool is also performed by the control device6. Thus, the control device6controls the entire operation of the robot1.

Note that, if the tool5chucks another tool, the hand part15is constituted by the tool5and the another tool. Moreover, the tool5is replaceable.

FIG. 4is a view illustrating the entire structure of the robot which performs a specific work. Below, directions of the pair of arms being wide spread is referred to as left-and-right directions, directions parallel to the axial center of the base shaft is referred to as vertical directions, and directions perpendicular to the left-and-right directions and the vertical directions is referred to as front-and-rear directions. As illustrated inFIG. 4, a conveyor71is disposed in front of the robot1. By the conveyor71, the workpiece72is conveyed in a direction of an arrow75. In this embodiment, the robot1performs the specific work to the moving workpiece72by the conveyor71. A “workspace” of the robot1is a space around the robot1, and is a space which covers the conveyor71. A pair of side walls71aand71bwhich define a flow of an object to be conveyed are provided on both sides of a belt of the conveyor71. A photoelectric sensor is provided to these side walls as the timing information detecting means7. A regulating member8is provided to the side wall71aat a location downstream of a light-emitting part7aof the photoelectric sensor. The regulating member8has a flat-plate shape and the principal surface thereof is oriented toward the conveyor71.

The photoelectric sensor has the light-emitting part7aprovided to one side wall71aon the robot1side, and a light-receiving part7bprovided to the other side wall71b. This photoelectric sensor is configured so that light, such as visible light or infrared light, is emitted from the light-emitting part7a, a change in quantity of light shaded by a detected object on the conveyor71is detected by the light-receiving part7b, and a detection signal is generated. Thus, the photoelectric sensor detects the workpiece72which is conveyed by the conveyor71. This detection signal is inputted into the control device6of the robot1(seeFIG. 3).

The hand part15(15A) of the first robotic arm10A of the robot1(hereinafter, may be referred to as “the first arm10A”) has a work tool73which performs the specific work to the workpiece72. Moreover, the hand part15(15B) of the second robotic arm10B (hereinafter, may be referred to as “the second arm10B”) has a guide tool74which supports the workpiece72and guides it in a given direction. The control device6(seeFIG. 3) is configured to control operations of the first arm10A and the second arm10B so that the guide tool74guides, according to timing information for which the workpiece72reaches the workspace of the robot1, the workpiece72located in the workspace into the workspace, and the work tool73performs the work to the workpiece72guided into the space.

In this embodiment, the workpiece72is a lunch box containing cooked rice and a plurality of kinds of side dishes. The “specific work” of the robot1is a work to pour sauce over a specific dish (e.g., a hamburg steak) in the lunch box. In this case, the work tool73is a sauce discharging device, and the guide tool74is a guide member for guiding the lunch box. The guide tool74has a shape bent in a substantially L-shape in a plan view.

Moreover, since the first and second arms10A and10B includes the hand parts15A and15B, respectively, as described above, operations by the tools of the hand parts15A and15B may be described as the operations by the first and second arms10A and10B.

Next, operation of the robot1of the above structure is described.FIG. 5is a flowchart illustrating one example of the operation of the robot1which performs the specific work.

First, the control device6acquires the detection signal from the timing information detecting means7, and generates the timing information for which the workpiece72reaches the workspace of the robot1(Step S1ofFIG. 5).FIG. 6is a view illustrating one example of the operation for detecting the timing information by the timing information detecting means7(photoelectric sensor). As illustrated inFIG. 6, the photoelectric sensor emits light, such as visible light or infrared light, from the light-emitting part7a, detects by the light-receiving part7bthe change in the quantity of light shaded by the workpiece (lunch box)72conveyed by the conveyor71, and generates the detection signal. Although the workpiece (lunch box)72conveyed by the conveyor71does not take a specific posture, the photoelectric sensor detects the workpiece (lunch box)72conveyed by the conveyor71. This detection signal is inputted into the control device6of the robot1(seeFIG. 3). The control device6generates the timing information for which the workpiece72reaches the workspace of the robot1based on the acquired detection signal. Here, a period of time from the workpiece72being detected by the photoelectric sensor to being conveyed by the conveyor71to the workspace of the robot1is stored beforehand in the memory part602. By adding the time described above to the detection timing of the photoelectric sensor, a timing at which the workpiece reaches the workspace of the robot1can correctly be calculated.

Next, the control device6guides into the space the workpiece72which is about to reach the workspace of the robot1, by the guide tool74according to the timing information (Step S2ofFIG. 5). The control device6controls the operations of the first and second arms10A and10B to cause the work tool73to perform the work to the workpiece72guided into the space (Step S3ofFIG. 5).

FIG. 7is a view illustrating one example of the operations of Steps S2and S3. The guide tool74is formed in the shape bent in the substantially L-shape in the plan view, and as illustrated inFIG. 7, the second arm10B moves the guide tool74in a direction of an arrow76. Thus, the workpiece (lunch box)72is guided along the guide tool74to one end side in width directions of the conveyor71. Here, while the one side surface of the workpiece (lunch box)72located in the workspace being supported by the guide tool74, another side surface of the workpiece (lunch box)72is guided toward the regulating member8. Thus, while the movement of the workpiece (lunch box)72in the conveyor conveying direction is regulated, the workpiece (lunch box)72is maintained in a given posture. Thus, the workpiece72located in the workspace can be stopped in the space.

On the other hand, the first arm10A performs a work to supply a given object to the workpiece (lunch box)72which became in the given posture. In the conveying state at this posture, the first arm10A causes the sauce discharging device which is the work tool73to discharge sauce, while operating the hand part15A so that the hand part15A repeats a reciprocating movement in arrow77directions (the width directions of the conveyor71). Thus, the sauce can be poured over the dish (e.g., the hamburg steak) located at the specific location of the workpiece (lunch box)72. Since the workpiece72is conveyed one by one by the conveyor71, if continuing the work (Step S4), the robot1returns to Step S1, where it stands by until the control device6acquires the next detection signal (until the next workpiece72is conveyed).

Therefore, according to this embodiment, the workpiece72located in the workspace is guided into the space by the guide tool74provided to the tip end of the arm10B, according to the timing information for which the moving workpiece72reaches the workspace of the robot1, and the work is performed to the workpiece72guided into the space by the work tool73provided to the tip end of the arm10A. Thus, the work can be performed to the moving workpiece72according to the timing information, without performing a tracking control etc. of the workpiece72. Thus, the robot which is capable of performing the specific work to the moving workpiece72can be realized with a comparatively simple structure.

Moreover, since the robot1is provided with the timing information detecting means7, the timing at which the workpiece72reaches the workspace of the robot1can correctly be calculated. Note that, although in this embodiment the workpiece72is detected by the transmission type photoelectric sensor provided near the conveyor71which conveys the workpiece, it may be detected by a photoelectric sensor of a so-called reflection type or a regressive reflection type, without being limited to the transmission type photoelectric sensor. Moreover, the timing information for which the workpiece72reaches may be calculated by analyzing an image of a fixedly-installed camera.

Moreover, it becomes easy to maintain the posture of the workpiece72by supporting the one side surface of the workpiece72located in the workspace by the guide tool74, and guiding the another side surface of the workpiece72toward the regulating member8.

Second Embodiment

Next, a second embodiment is described. Below, description of the configuration which is common to the first embodiment is omitted, and only different configuration is described.

FIG. 8is a block diagram illustrating an outline configuration of the control device of the robot1according to the second embodiment. As illustrated inFIG. 8, the robot1of this embodiment differs in that it further includes a contact sensor9which detects the guide tool74contacting the workpiece72and outputs a detection signal to a control device6A. Although in this embodiment the contact sensor9uses a distributed type pressure sensor, it may use other types of contact sensors, as long as it is capable of detecting the contact with an object.

FIG. 9is a view illustrating one example of operation by the robot1. The guide tool74is formed in the shape bent in the substantially L-shape in the plan view, and has a long-side part74aand a short-side part74b. In this embodiment, the contact sensor9is provided to an inner surface of the short-side part74b. The contact sensor9detects that the workpiece (lunch box)72contacts the inner surface of the short-side part74bof the guide tool74.

As illustrated inFIG. 9, the control device6A moves the guide tool74of the second arm10B from the outside of the conveyor71in a direction of an arrow76, according to the timing information. Here, if the control device6A receives from the contact sensor9the detection signal indicative of detecting that the workpiece (lunch box)72contacts the inner surface of the short-side part74bof the guide tool74, it controls the guide tool74to follow the motion of the workpiece (lunch box)72conveyed by the conveyor71, while supporting a tip end and a side surface of the workpiece (lunch box)72located in the workspace by the short-side part74band the long-side part74aof the guide tool74.

On the other hand, the first arm10A performs the work to supply the given object to the workpiece (lunch box)72which became in the given posture by the guide tool74. The first arm10A causes the sauce discharging device which is the work tool73to discharge the sauce, while following the motion of the workpiece (lunch box)72conveyed by the conveyor71and operating the hand part15A so that it repeats the reciprocating movement in the arrow77directions (the width directions of the conveyor71). Thus, the sauce can be poured over the dish (e.g., the hamburg steak) at the specific location of the workpiece (lunch box)72. Thus, in this embodiment, the control device6A controls the operation of the first arm10A to perform the specific work by the work tool73to the workpiece72when the contact sensor9detects that the guide tool74contacts the workpiece72.

Note that, although in this embodiment it is configured so that the contact sensor9is provided to the inner surface of the short-side part74bof the guide tool74and the specific work is performed while the motion of the workpiece72conveyed by the conveyor71is followed. The contact sensor9may be provided to an inner surface of the long-side part74a, and after completely stopping the motion of the workpiece72on the conveyor71by the long-side part74aof the guide tool74, the specific work may be performed. The contact sensor9detects that the workpiece (lunch box)72contacts the inner surface of the long-side part74aof the guide tool74, and outputs the detection signal to the control device6A. The control device6A controls the operation of the second arm10B to support the one side surface of the workpiece (lunch box)72located in the workspace by the long-side part74aof the guide tool74, and guide the another side surface of the workpiece (lunch box)72toward the regulating member8. Thus, the movement of the workpiece (lunch box)72in the conveyor conveying direction is regulated and the workpiece (lunch box)72is maintained in the given posture. Thus, the sauce may be poured over the dish (e.g., the hamburg steak) at the specific location of the workpiece (lunch box)72after completely stopping the motion of the workpiece72on the conveyor71.

Note that, although in each embodiment described above it is the work to apply the sauce to the content in the lunch box, it may be a work to apply soy sauce, dressing, etc. or a work to put contents, such as dishes, into the lunch box.

Note that although in each embodiment described above the sauce is poured while the lunch box is conveyed, the conveyor may be stopped after the lunch box becomes a specific posture and the sauce may be poured over the lunch box in the stationary state.

It is apparent for a person skilled in the art that many improvements and other embodiments of the present disclosure are possible from the above description. Therefore, the above description is to be interpreted only as illustration, and it is provided in order to teach a person skilled in the art the best mode that implements the present disclosure. Details of the structures and/or the functions may substantially be changed without departing from the spirit of the present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is useful to the robot which performs a work similar to the work conventionally performed by a human.

DESCRIPTION OF REFERENCE CHARACTERS