JP2012218093A - Robot system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot system that distributes a series of work into a plurality of work robots, and improves productivity without causing other robots to wait even if a delay occurs in any of work sections for some work robots.SOLUTION: The robot system assigns n work sections to robot controllers 4a-4d provided at arm robots 6a-6d respectively. M work sections less than n sections are assigned to a robot controller 4e provided at an arm robot 6e. When a delay occurs in a work of a work section at any arm robot 6, reassignment is executed, to assign a work section that has not been executed again to a robot controller of an arm robot located downstream of the arm robot in delay. N work sections, at a maximum, can be assigned again to the robot controllers in the reassignment.

Description

  The present invention eliminates a delay without stopping each work robot when a work delay occurs in some work robots in cell production in which a series of work is divided and executed by a plurality of work robots. Related to robot systems.

  At the assembly work site, instead of the conventional consistent belt conveyor production method, a distributed cell production method has been introduced, and steady results have been achieved. Furthermore, unmanned operation, that is, the cell production process is replaced by a group of multiple robots. Synchronous control between work robots is important in cell production by a plurality of work robots. In order to efficiently assemble a single workpiece by dividing a series of assembly work steps and assigning them to a plurality of work robots, it is necessary to have a cycle time for performing the work of each work robot. If a delay occurs in the assigned work process in some work robots, a waiting time is generated in the adjacent work robot, and finally the productivity of the entire assembly line is hindered.

  FIG. 12 is a time chart showing a case where a delay occurs in the conventional robot system, and here, shows a robot system in which an assembly process is realized by five work robots (R1 to R5).

  The horizontal axis represents the cycle time, and the vertical axis represents each work robot. As the cycle time progresses, the transition of the work W to be worked on by each work robot can be seen. For example, the workpiece W4 is assembled by the work robot R2 at the cycle time T1, and the same workpiece W4 is transferred to the work robot R3 at the next cycle time T2, and the next assembly is performed. The assembly process of the work W4 is completed by assembling the work robot R5 at the cycle time T4.

  On the other hand, in the assembly work of the workpiece W5, the work robot R2 has a delay at the cycle time T2. At this time, the work robot R2 does not complete the assembly process in which the work W5 being assembled is allocated within a predetermined cycle time. Therefore, at the next cycle time T3, the work robot R1 located upstream of the work robot R2 has completed the assembly process of the work W6 assigned to the work robot R1, but immediately the work W6 is changed to the work robot R2. I can't pass it. Therefore, the delay time D1 occurs until the assembly of the next workpiece W7 is started.

  In addition, at the same cycle time T3, the assembly process of the work W4 assigned to the work robot R3 is completed for the work robot R3 located downstream of the work robot R2. However, the workpiece W5 cannot be immediately received from the work robot R2, and a delay time D2 occurs until the assembly of the workpiece W5 is started.

  Thereafter, the delay time D3 is spread to the work robot R4 at the cycle time T4, and the delay time D4 is spread to the work robot R5 at the cycle time T5. Then, the assembly completion time of all the workpieces after the workpiece W5 is delayed by the delay time D5 from the plan. Therefore, it can be seen that the delay that has occurred once is accumulated without being eliminated.

  In order to reduce the influence of such work delay on other work robots, an apparatus in which a stocker is provided between work robots is disclosed (see Patent Document 1). Specifically, a stocker is placed between each work robot, and when a delay occurs between adjacent work robots, the work that has been assembled is transferred to a stocker provided between the work robots. Then, move on to the next workpiece assembly. Conversely, when a delay occurs in the upstream work robot, the work robot wait time is eliminated by transferring the next workpiece from the stocker provided between the upstream robot and continuing the work assembly work. ing.

JP-A-11-198074

  However, by providing a stocker between each work robot, adjacent work robots will not stop immediately and move to a waiting operation, but there will be a delay between some work robots before the work exists in the stocker itself. Indicates that this has occurred. Although this delay can be prevented from spreading to other robots, the generated delay cannot be eliminated. In addition, there is a problem that the provision of a stocker increases costs and secures a space.

  Therefore, the present invention provides a robot system that prevents a work delay caused by some work robots from spreading to another work and improves the productivity of a plurality of work robots. For the purpose.

  The present invention is arranged side by side in the workpiece transfer direction for sequentially transferring workpieces, a plurality of work robots that share a series of work performed on the workpiece, a robot controller provided in each of the plurality of work robots, In a robot system comprising a main controller connected to a plurality of robot controllers, the main controller stores a plurality of work sections obtained by dividing the series of work, and stores in the storage unit The plurality of work divisions are divided into n (≧ 2 positive integers) robot controllers provided in work robots other than the work robots located at the most downstream in the workpiece transfer direction among the plurality of robot controllers. The robot controller provided in the work robot located on the most downstream side in the workpiece transfer direction has m (<n A positive integer), an allocating unit that executes an allocation process that is allocated in the order of work, and a synchronization control unit that sends a synchronization signal indicating the timing of conveying the workpiece downstream in the workpiece conveyance direction to each robot controller at a certain time interval; And each robot controller causes the work robot to transfer the work downstream in the work transfer direction at the timing of the synchronization signal sent by the synchronization control unit, and to the work transferred from the work transfer direction upstream A processing unit for causing the work robot to execute the work of the assigned work category, and an operation that is predicted not to be completed within the time interval when a delay occurs in the work category of the work robot. A notification unit for notifying the main controller of information on work divisions, and the main controller includes the notification unit. When the above information is notified, the robot controller provided in the work robot located downstream in the work transfer direction from the work robot in which the work in the work category is delayed among the plurality of robot controllers is not implemented. It is characterized by having a reallocation part which performs the reallocation process which reallocates the work classification which is these in order of work by making n into an upper limit.

  According to the present invention, when a series of work is performed on a work, even if a work work is delayed in a work robot, the work robot in the downstream work group does not perform the work in the work work in progress. As a result, each work robot can finish the work within a certain time interval. As a result, it is possible to prevent the influence of the delay due to the work of a part of the work division in a certain work robot from spreading to the work of the work robot with respect to another work, thereby improving the productivity of the plurality of work robots.

1 is a block diagram showing a schematic configuration of a robot system according to a first embodiment of the present invention. It is a control block diagram which shows the control apparatus of the robot system shown in FIG. It is explanatory drawing which shows the some work division obtained by dividing a series of work. It is a schematic explanatory drawing showing the assignment of the responsible job, (a) before the occurrence of the delay, (b) shows after the occurrence of the delay. It is a time chart which shows the flow of work by each arm robot. It is a block diagram which shows schematic structure of the robot system 1A which concerns on 2nd Embodiment of this invention. It is a control block diagram which shows the control apparatus of the robot system shown in FIG. It is a schematic explanatory drawing showing the assignment of the responsible job, (a) before the occurrence of the delay, (b) shows after the occurrence of the delay. It is a time chart which shows the flow of work by each arm robot. It is a block diagram which shows schematic structure of the robot system 1A which concerns on 3rd Embodiment of this invention. 4A and 4B are schematic explanatory diagrams showing assignment of a job in charge, where FIG. 5A shows before an error that causes the arm robot to become inoperable, and FIG. It is a time chart which shows the flow of work by each work robot when delay arises in the conventional robot system.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing a schematic configuration of the robot system according to the first embodiment of the present invention. The robot system 1 includes a plurality of robot stations 3. In FIG. 1, the robot station 3 is composed of five robot stations 3 (3a to 3e), but is not limited to five.

  Each robot station 3 includes an arm robot 6 (6a to 6e) which is a work robot, and a robot controller 4 (4a to 4e) which is connected to the arm robot 6 and controls the arm robot 6. A cell controller 2, which is one main controller, is connected to the plurality of robot controllers 4a to 4e via a communication line 11. The arm robot 6 is an articulated manipulator, and can grip and transport the workpiece W, and can perform operations such as processing and assembly on the workpiece W (W1 to W5).

  Each robot station 3 has a work table 5 (5a to 5e) for assembling the workpiece W, a workpiece fixing unit 7 (7a to 7e), and an assembly member installation unit to which the arm robot 6 is fixed. 8 (8a to 8e). The workpiece fixing unit 7 fixes the workpiece W that has been conveyed. A member to be assembled to the workpiece W is installed in the assembly member installation unit 8. The workpiece fixing unit 7 and the assembly member installation unit 8 are provided on the work table 5.

  In the first embodiment, each robot station 3 has only one arm robot 6. However, the present invention is not limited to this, and two robot arms, that is, two-arm arm robots are provided as work robots. You may do it. At that time, the robot controller 4 has a dual-arm synchronous control function.

  In the first embodiment, the robot stations 3 a to 3 e are arranged in a line, and each arm robot 6 is configured to be able to grip the workpiece W and transfer it to the work table 5 of the adjacent robot station 3. . A work loading table 9 is disposed upstream of the workpiece W in the robot station 3a in the workpiece conveyance direction, and a workpiece loading table 10 is disposed downstream of the workpiece W in the robot station 3e in the workpiece conveyance direction. As a result, the workpieces W loaded from the workpiece loading table 9 are sequentially conveyed in the order of the robot stations 3a → 3b → 3c → 3d → 3e, the workpieces W are assembled in order, and are conveyed to the workpiece unloading table 10. In this way, a series of operations performed on the workpiece W are performed in a shared manner by the plurality of arm robots 6a to 6e.

  The workpiece W before assembly is set on the workpiece loading table 9 by a workpiece loading means (not shown) or a worker. The workpiece carry-out table 10 is a table for delivering the workpiece W that has been assembled by the plurality of robot stations 3a to 3e. The assembled workpiece W is placed on the workpiece carrying table 10 by the arm robot 6e of the robot station 3e and taken out by a workpiece carrying means (not shown) or a worker.

  FIG. 2 is a control block diagram showing a control device of the robot system 1 shown in FIG. FIG. 3 is an explanatory diagram showing a plurality of work sections obtained by dividing a series of work. The cell controller 2 shown in FIG. 2 is for controlling the robot stations 3a to 3e in synchronization. First, as shown in FIG. 3, a series of operations (hereinafter referred to as “all jobs”) 40 until the assembly operation is completed is divided into a plurality of more detailed operation categories (hereinafter referred to as “single job”). It is divided into 41a to 41n. Then, the cell controller 2 collects several single jobs as a work classification group (hereinafter referred to as “in-charge job”) 42 (42a to 42e) executed by the arm robot 6 of each robot controller 4. (4a to 4e). Each single job 41 is divided so that the assumed work time of the arm robot 6 (planned work time assuming no delay) is substantially the same. Here, in FIG. 3, single jobs 41a to 41n, which are work divisions, are represented by Job [A] to Job [N]. Hereinafter, the work divisions are represented by single Job 41 (41a to 41n) or Job [A] to Job [N] will be described as appropriate.

  Each robot controller 4 shown in FIG. 2 receives the responsible job 42 from the cell controller 2 and transmits the work status and error information of the arm robot 6. Each robot controller 4 causes the arm robot 6 to perform the work of the assigned job 42, receives the workpiece W from the arm robot 6 of the robot station 3 in the previous process and receives the next workpiece W at the same timing according to the command of the cell controller 2. Start assembly work. At this time, the robot station 3a receives the workpiece from the workpiece carry-in table 9, and the robot station 3e discharges the assembled workpiece to the workpiece carry-out table 10 as one process of the job in charge.

  First, the configuration of the cell controller 2 will be described. The cell controller 2 includes a single job database unit 20 as a storage unit, a robot station monitor unit 21, and a job progress management unit 22 as a work progress management unit. Further, the cell controller 2 includes a responsible job allocating unit 23 as an allocating unit, a responsible job reallocating unit 24 as a reallocating unit, and a synchronization control unit 25.

  In the single job database unit 20, data of a plurality of single jobs 41a to 41n constituting all the jobs 40 is stored. The data of the single job 41 may be an execution command, but may be information necessary for allocating the job 42 to each robot controller 4 such as information related to the single job, for example, standard man-hour time and necessary tools.

  The robot station monitor unit 21 manages the status of each robot station 3 such as an error occurrence. The job progress management unit 22 manages the work status of the arm robot 6 of each robot station 3.

  The assigned job allocating unit 23 executes an allocation process for assigning assigned job 42 to the robot controller 4 of each robot station 3. More specifically, the assigned job allocating unit 23 reads data of a plurality of single jobs 41 a to 41 n from the single job database unit 20. Then, the assigned job allocating unit 23 outputs data of each assigned job 42a to 42e in which several single jobs 41 are grouped in the work order to each robot controller 4a to 4e. As a result, the assigned job 42 is assigned to each robot controller 4.

  Specifically, the assigned job allocating unit 23 sends n (≧ 2 positive integer) to the robot controllers 4a to 4d provided in the arm robots 6a to 6d other than the arm robot 6e located on the most downstream side in the workpiece transfer direction. ) Allocate a single job 41. In the first embodiment, n = 3, that is, three single jobs 41 constitute the responsible jobs 42a to 42d. Note that the number of the single job 41 allocated to the robot controllers 4a to 4d connected to the work robots other than the work robot located on the most downstream side in the workpiece transfer direction is not limited to three, and may be two or more.

  On the other hand, the assigned job allocating unit 23 allocates m (<n positive integer) single jobs 41 to the robot controller 4e provided in the arm robot 6e located on the most downstream side in the workpiece transfer direction. In the first embodiment, m is a value smaller than n, and therefore m = 2, that is, two single jobs 41 that are 2/3 of n, the responsible job 42e is configured. Note that the number of the single job 41 allocated to the robot controller 4e is not limited to 2/3 of n, and can be arbitrarily set as long as m is smaller than n.

  The assigned job reallocation unit 24 performs a review each time one cycle time is executed based on information from the robot station monitor unit 21 and information from the job progress management unit 22. Then, when there is a delay in the work of the single job 41 for a certain work W, the assigned job reallocation unit 24 executes the reallocation processing of the single job 41 (reconstructed assigned job).

  The synchronization control unit 25 controls the robot controllers 4 that are in operation to be switched simultaneously at the same time interval. Specifically, the synchronization control unit 25 sends a synchronization signal indicating the timing of conveying the workpiece W to each robot controller 4 in order to deliver the workpiece W to the arm robot 6 downstream in the workpiece conveyance direction (left direction in FIG. 1). Sends out at regular time intervals (cycle time). At this time, a major feature of the present embodiment is that it instructs the switching of work even if each job 42 instructed to each robot controller 4 is not necessarily completed, that is, sends a synchronization signal.

  Here, the number of the single job 41 that fits in plan within one cycle time is n. Therefore, the cycle time, that is, the time interval for outputting the synchronization signal is set so that each of the responsible jobs 42a to 42d is composed of n single jobs 41 and the responsible job 42e is composed of m single jobs 41.

  Next, the configuration of each robot controller 4 will be described. Each robot controller 4 includes a command storage unit 26 (26a to 26e) for storing execution commands, a responsible job processing unit 27 (27a to 27e) as a processing unit, a motor drive unit 28 (28a to 28e), a sensor And a detection unit 29 (29a to 29e). Each robot controller 4 includes a station state management unit 30 (30a to 30e) and a job progress notification unit 31 (31a to 31e) as a notification unit.

  FIGS. 4A and 4B are schematic explanatory diagrams showing the assignment of the responsible job 42. FIG. 4A shows a state before the occurrence of delay, and FIG. 4B shows a state after the occurrence of delay. The robot controller 4 shown in FIG. 2 will be described with reference to FIG. 4A. The assigned robots 42a to 42e are assigned to the robot controllers 4a to 4e. Executable Jobs 43a to 43e are set in the robot controllers 4a to 4e. Executable Jobs 43a to 43e are work division groups that are a set of a plurality of single Jobs 41, and each responsible job processing unit 27a to 27e executes each single Job 41 of the responsible Job 42 within the range of the executable Jobs 43a to 43e. It is configured to be possible.

  More specifically, first, the command storage unit 26 has an instruction for operating the arm robot 6 and an execution command for causing the arm robot 6 to execute each single job 41 of the assigned job 42. It is remembered. For example, the command storage unit 26a stores execution commands for causing the arm robot 6a to execute Job [A] to Job [D].

  Then, the assigned job processing unit 27 interprets the assigned job 42 assigned by the cell controller 2, and sequentially performs the work of each single job 41 of the assigned job 42 on the workpiece W transferred from the upstream side of the workpiece transfer direction. The arm robot 6 is executed. Specifically, the responsible job processing unit 27 reads out and executes the execution command corresponding to each single job 41 of the responsible job 42 from the command storage unit 26, thereby causing the arm robot 6 to perform the work. For example, the responsible job processing unit 27a reads execution commands corresponding to Job [A] to Job [C] of the responsible job 42a from the command storage unit 26a, and causes the arm robot 6a to perform work according to the execution command. Here, since the command storage unit 26a stores execution commands for causing the arm robot 6a to execute Job [A] to Job [D], the executable Job 43a has Job [A] to Job [D]. It will be set to. Similarly, in FIG. 4A, the executable Job 43b is Job [C] to Job [G], the executable Job 43c is Job [F] to Job [J], and the executable Job 43d is Job [I] to Job [M]. The executable job 43e is set to Job [L] to Job [N].

  The executable job 43 set in the robot controller 4 connected to the two arm robots 6 adjacent to each other is set so that the single job 41 overlaps each other. For example, in the executable Job 43b and the executable Job 43c, Job [F] and Job [G] are set redundantly.

  In addition, the responsible job processing unit 27 causes the arm robot 6 to convey the workpiece W downstream in the workpiece conveyance direction at the timing of the synchronization signal transmitted by the synchronization control unit 25 of the cell controller 2. For example, the responsible job processing unit 27a causes the arm robot 6a to transfer the workpiece W to the workpiece fixing unit 7b on the work table 5b arranged downstream in the workpiece transfer direction at the timing of the synchronization signal. Further, the responsible job processing unit 27e causes the arm robot 6e to transport the workpiece W to the workpiece unloading table 10 arranged downstream in the workpiece conveying direction at the timing of the synchronization signal. By the above operation, the plurality of arm robots 6a to 6e conveys the workpiece W all at once in the workpiece conveyance direction.

  The motor driving unit 28 drives the motor of the arm robot 6 and the motor of the workpiece fixing unit 7 under the control of the responsible job processing unit 27. That is, the responsible job processing unit 27 controls the operation of the arm robot 6 by controlling the motor driving of the arm robot 6 by the motor driving unit 28. The sensor detection unit 29 performs detection using a sensor provided in the arm robot 6 and a sensor provided in the workpiece fixing unit 7. The station state management unit 30 manages the error status of the robot station 3 from the information of the motor drive unit 28 and the sensor detection unit 29, and notifies the cell controller 2 if an error has occurred.

  The job progress notification unit 31 notifies the cell controller 2 of the progress status of the responsible job 42 that has received an instruction at the current cycle time. Further, the job progress notifying unit 31 stores information on the unexecuted single job 41 that is predicted not to be completed within the cycle time T when the work of the single job 41 in the arm robot 6 is delayed. The cell controller 2 is notified. The job progress management unit 22 of the cell controller 2 processes the information received from the job progress notification unit 31 of the robot controller 4 and outputs it to the assigned job reallocation unit 24.

  With the above configuration, the assigned job allocation unit 23 of the cell controller 2 allocates each assigned job 42a to 42e to each robot controller 4a to 4e. The synchronization control unit 25 outputs a synchronization signal to each robot controller 4a to 4e at a constant time interval (cycle time T). The job processing unit 27 in charge of each of the robot controllers 4a to 4e causes the arm robot 6 to convey the workpiece W downstream in the workpiece conveyance direction at every cycle time T in synchronization with the synchronization signal. Then, each assigned job processing unit 27 causes the arm robot 6 to sequentially perform the assigned job 42 work on the workpiece W transferred from the upstream side of the workpiece transfer direction. When there is no delay in the work of each assigned job 42 by each arm robot 6, the work of each assigned job 42 allocated by the assigned job allocating unit 23 can be completed within the cycle time T.

  Next, the operation of the cell controller 2 and each robot controller 4 when a delay occurs in the work of the single job 41 in the job 42 in charge in some arm robots 6 will be described. FIG. 4B illustrates an example in which the job [Job] in the assigned job 42b is delayed in the arm robot 6b. FIG. 5 is a time chart showing a work flow by each arm robot 6.

  When a delay occurs in the operation of a single job in any of the arm robots 6, the job progress notification unit 31 of the robot controller 4 connected to the arm robot 6 in which the delay occurs causes information on the unexecuted single job. Is sent (transmitted) to the cell controller 2. For example, the job progress notification unit 31b of the robot controller 4b has information indicating that Job [F] has not been performed because a delay occurs in the job [E] by the arm robot 6b with respect to the workpiece W5 at the cycle time T2. Is notified to the cell controller 2. The job progress management unit 22 of the cell controller 2 outputs a signal indicating that the job [F] is not performed by the arm robot 6b to the work W5 to the assigned job reallocation unit 24.

  The assigned job reallocation unit 24 has not yet performed the robot controllers 4c to 4e provided in the arm robots 6c to 6e that are located downstream of the arm robot 6b in which the work of Job [E] is delayed in the work transfer direction. Reallocate a certain Job [F] to Job [N]. At that time, the assigned job reallocation unit 24 reassigns the upper limit of the number of single jobs 41 to be assigned to the respective robot controllers 4c to 4e in the order of work. That is, the assigned job reallocation unit 24 reallocates the assigned job 44c including Job [F] to Job [H] to the robot controller 4c. The assigned job reallocation unit 24 reassigns assigned job 44d including Job [I] to Job [K] to the robot controller 4d. The assigned job reallocation unit 24 reassigns assigned job 44e including Job [L] to Job [N] to the robot controller 4e.

  In other words, Job [F] that has not been executed by the robot controller 4b is allocated to the robot controller 4c connected to the arm robot 6c adjacent to the arm robot 6b where the delay has occurred. As a result, Job [I] cannot be executed, and Job [I] is assigned to the robot controller 6d connected to the arm robot 6d adjacent to the arm robot 6c. Similarly, Job [L] is allocated to the robot controller 6e.

  As shown in FIG. 5, the assigned job reallocation unit 24 performs the reallocation process only for the work W5 in which the work delay has occurred, and for the work W other than the work W5. Since no work delay has occurred, no reallocation processing is performed. Therefore, for the work W other than the work W5, the work of the single job 41 of the assigned job 42 allocated by the assigned job allocating unit 23 is executed.

  As described above, since the reallocation processing is executed for the assigned job reallocation unit 24, the assigned job processing unit 27c of the robot controller 4c of the robot station 5c performs job [F] to job [H] at the cycle time T3. The arm robot 6c performs the above operation. Also, the job processing unit 27d in charge of the robot controller 4d of the robot station 5d causes the arm robot 6c to perform the jobs [Job] [I] to Job [K] at the cycle time T4. In addition, the job processing unit 27e in charge of the robot controller 4e of the robot station 5e located on the most downstream side in the workpiece transfer direction causes the arm robot 6e to perform jobs [L] to Job [N] at the cycle time T5.

  That is, m (= 2) single job 41 is allocated to the robot controller 4e by the assigned job allocating unit 23, but there is one single job 41 that has not been executed in the arm robot 6b. Three single jobs 41 are allocated by the reallocation unit 24. Thus, even if a delay occurs in the operation of any single job 41 by the arm robots 6a to 6d, the single job 41 to be performed by the arm robot 6e located on the most downstream side is increased within the range of the cycle time T. Can do.

  Thereby, even if a delay occurs in the work of a part of the single job 41, each robot controller 4a to 4e can finish the work of the assigned single job 41 within the cycle time T. Accordingly, for example, a delay in the job of Job [E] by the arm robot 6b, which occurs when a series of operations are performed on the workpiece W5, affects the operations of the arm robots 6a to 6e with respect to another workpiece W. Can be prevented. That is, it is possible to prevent waiting time in each of the arm robots 6a to 6e when performing work on another workpiece W. Therefore, the productivity of the workpiece W by the plurality of arm robots 6a to 6e is improved.

[Second Embodiment]
Next, a robot system according to a second embodiment of the invention will be described. FIG. 6 is a block diagram showing a schematic configuration of a robot system 1A according to the second embodiment of the present invention. FIG. 7 is a control block diagram showing a control device of the robot system 1A shown in FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, the robot system 1A includes a robot station 3f that is a buffer disposed adjacent to the robot station 3e (arm robot 6e) located on the most downstream side in the workpiece transfer direction. The robot station 3f includes an arm robot 6f that is an auxiliary work robot having the same configuration as the arm robots 6a to 6e, and a robot controller 4f that is an auxiliary robot controller having the same configuration as the robot controllers 4a to 4e. Yes. The robot station 3f is similar to the work table 5f having the same configuration as the work tables 5a to 5e, the work fixing unit 7f having the same configuration as the work fixing units 7a to 7e, and the assembly member installation units 8a to 8e. It has an assembly member installation portion 8f having a configuration.

  The robot controller 4f includes a command storage unit 26f, a responsible job processing unit 27f as an auxiliary processing unit, a motor driving unit 28f, a sensor detection unit 29f, a station state management unit 30f, and a job progress notification unit 31f.

  8A and 8B are schematic explanatory diagrams showing assignment of the responsible job 42. FIG. 8A shows a state before the occurrence of delay and FIG. 8B shows a state after the occurrence of delay. In the second embodiment, the assigned job allocating unit 23 performs an allocation process for allocating assigned jobs 42a to 42e to the robot controllers 4a to 4e as in the first embodiment. Does not allocate a job in charge. Further, an executable Job 43f is set in the robot controller 4f. This executable Job 43f is the same as all or part of the responsible Job 42e. In the second embodiment, the executable Job 43f is the same as a part of the executable Job 43e, for example, Job [L], Job [M], and Job [N]. That is, the command storage unit 26f stores execution commands for executing Job [L], Job [M], and Job [N].

  With the above configuration, when there is no delay in the work of each assigned job 42 by each of the arm robots 6a to 6e, the work of each assigned job 42 assigned by the assigned job allocating unit 23 is completed within the cycle time T. be able to.

  Next, as shown in FIG. 8B, it is assumed that a delay occurs in the job [D] in the arm robot 6b, and Job [E] and Job [F] are not executed.

  The job progress notification unit 31b of each robot controller 4b notifies the cell controller 2 of information indicating that Job [E] and Job [F] are not executed. The job progress management unit 22 of the cell controller 2 outputs a signal indicating that Job [E] and Job [F] operations by the arm robot 6 b are not performed to the responsible job reallocation unit 24.

  Then, the assigned job reallocation unit 24 executes reallocation processing. That is, the assigned job reallocation unit 24 reassigns assigned job 44c composed of Job [E] to Job [G] to the robot controller 4c. The assigned job reallocation unit 24 reassigns assigned job 44d composed of Job [H] to Job [J] to the robot controller 4d. The assigned job reallocation unit 24 reassigns assigned job 44e including Job [K] to Job [M] to the robot controller 4e.

  Here, the assigned job reallocation unit 24 allocates the robot controller 4e to the remaining job [N] exceeding the upper limit n (= 3) within a certain time interval (T Since it cannot be processed in (), the robot controller 4f is assigned. In the second embodiment, the assigned job 44f composed of Job [N] is reassigned to the robot controller 4f.

  FIG. 9 is a time chart showing the flow of work by each arm robot 6. At cycle time T2 shown in FIG. 9, among the assigned job 42b in the arm robot 6b, Job [E] and Job [F] are unexecuted jobs. Therefore, at the next cycle time T3, the arm robot 6c performs work from Job [E] as the responsible job 44c according to the instruction from the cell controller 2. Similarly, the arm robot 6d performs work from Job [H] at cycle time T4, and the arm robot 6e performs work from Job [K] at cycle time T5.

  Job 44e assigned to the robot controller 4e connected to the arm robot 6e located on the most downstream side is assigned to 2/3 in time compared to other robot controllers, but the assembly process of the workpiece W5 within the cycle time T5. Can't complete. Therefore, at the next cycle time T6, the buffer robot controller 4f executes Job [N] as the responsible job 44f. Completion of the assembly of the workpiece W5 exceeds the scheduled cycle time T5, but the next workpiece W6 has been assembled within the scheduled cycle time T6, and it can be seen that the delay of the subsequent workpiece assembly can be prevented. .

  As described above, in the second embodiment, by providing the buffer arm robot 6f adjacent only to the arm robot 6e located on the most downstream side, the cost and installation space of the entire robot system 1A can be reduced.

[Third Embodiment]
Next, a robot system according to a third embodiment of the invention will be described. FIG. 10 is a block diagram showing a schematic configuration of a robot system 1B according to the third embodiment of the present invention. The control block diagram of the control device of the robot system 1B is the same as that in FIG. 2 and will be described with reference to FIG. Note that in the present third embodiment, identical symbols are assigned to configurations similar to those in the first embodiment and descriptions thereof are omitted.

  First, the third embodiment is different from the first embodiment in that, instead of directly transferring the workpiece W, the arm robot 6 moves the transfer tray 12 (12x, 12a to 12e, 12y) on which the workpiece W is placed. This is a point that is gripped and conveyed. On the transport tray 12, a work W and an assembly unit 13 (13 x, 13 a to 13 e, 13 y) that is an assembly member and a jig to be assembled to the work W are placed. When the transfer tray 12 is delivered, the work W on the transfer tray 12 is fitted to the work fixing unit 7 of each robot station 3 and can be driven at the time of assembling work according to an instruction from the motor drive unit 28. The assembly unit 13 is equipped with parts and jigs to be assembled by all jobs, and the number of executable jobs at each robot station 3 can be increased. For example, if parts and jigs used in all jobs are mounted on the assembling unit 13, any robot station 3 can execute a single job included in all jobs in terms of hardware configuration.

  In the present third embodiment, when a delay occurs in the operation of a single job by any one of the plurality of arm robots 6a to 6e, the cell controller 2 is the same as in the first embodiment. The assigned job reallocation unit 24 performs the reallocation process.

  By the way, one of the arm robots 6a to 6e may be unable to work due to a failure or the like. The station state management unit 30 of the robot controller 4 according to the third embodiment is configured to notify the cell controller 2 of error information indicating that the arm robot 6 cannot work.

  The robot station monitor unit 21 of the cell controller 2 functions as a detection unit that detects which arm robot 6 has become inoperable by processing error information. Based on the detection result, the assigned job allocating unit 23 provides the allocation processing described in the first embodiment to the arm robots excluding the arm robots incapable of working among the plurality of robot controllers 4a to 4e. To the specified robot controller.

  11A and 11B are schematic explanatory diagrams showing the assignment of the assigned job 42. FIG. 11A shows the state before the occurrence of an error that makes the arm robot 6 unable to work, and FIG. Note that the executable jobs 43a to 43e set in the robot controllers 4a to 4e may be all jobs, but may be configured as a part of a single job as shown in FIG.

  As shown in FIG. 11A, as in the first embodiment, the robot controllers 4a to 4d are assigned job jobs 42a to 42d composed of n (= 3) single jobs. The robot controller 4e is assigned a responsible job 42e consisting of m (= 2) single jobs.

  Next, as shown in FIG. 11B, for example, the case where the arm robot 6b becomes inoperable will be described. The assigned job allocating unit 23 assigns assigned jobs 45a, 45c, 45d, and 45e to the robot controllers 4a, 4c, 4d, and 4e connected to the arm robots 6a, 6c, 6d, and 6e except the arm robot 6b. To do. Note that no single job is assigned to the robot controller 4b, in other words, the number of single jobs included in the assigned job 45b is zero.

  Since the number of single jobs to be processed as jobs in charge of the robot controllers 4a, 4c, and 4d is increasing, the cycle time T ′ is set longer than the initial cycle time T by the increment of the single job. . That is, the synchronization control unit 25 of the cell controller 2 transmits a synchronization signal to each robot controller 4 in accordance with the cycle time T ′.

  As described above, in the third embodiment, even when the assigned job cannot be assigned to a certain arm robot 6, the assembly process can be performed constantly at the cycle time T ′ after review without stopping the robot system 1B. Is possible.

  In addition, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. The above embodiment relates to a work assembly line, but the present invention can be applied to a production line in which a series of work processes are divided and executed by a plurality of robot stations, and various work other than the production line can be performed. It is also applicable to the line.

DESCRIPTION OF SYMBOLS 1,1A, 1B ... Robot system, 2 ... Cell controller (main controller), 4a-4e ... Robot controller, 4f ... Robot controller (auxiliary robot controller), 6a-6e ... Arm robot (working robot), 6f ... Arm Robot (auxiliary work robot), 20 ... single job database unit (storage unit), 21 ... robot station monitor unit (detection unit), 23 ... responsible job allocation unit (allocation unit), 24 ... responsible job re-allocation unit ( Reassignment unit), 25 ... synchronization control unit, 27a to 27e ... responsible job processing unit (processing unit), 27f ... responsible job processing unit (auxiliary processing unit), 31a to 31e ... job progress notification unit (notification unit)

Claims (3)

A plurality of work robots arranged side by side in a work transfer direction for sequentially transferring a work and performing a series of operations performed on the work, a robot controller provided in each of the plurality of work robots, and the plurality of robot controllers In a robot system comprising a main controller connected to
The main controller is
A storage unit for storing a plurality of work sections obtained by dividing the series of work;
A plurality of work categories stored in the storage unit are assigned n (≧ 2 positive values) to a robot controller provided in a work robot other than the work robot located at the most downstream side in the work transfer direction among the plurality of robot controllers. An allocation unit that executes an allocation process to allocate m (<n positive integers), the order of work, to the robot controller provided in the work robot located at the most downstream in the workpiece transfer direction;
A synchronization control unit that sends a synchronization signal indicating the timing of conveying the workpiece downstream in the workpiece conveyance direction to the robot controllers at regular time intervals,
Each robot controller is
The work robot causes the work robot to transfer the work downstream in the work transfer direction at the timing of the synchronization signal sent by the synchronization control unit, and the work robot assigns work in the assigned work classification to the work transferred from the work transfer direction upstream. A processing unit to be executed,
A notification unit that notifies the main controller of information on an unexecuted work category that is predicted not to be completed within the time interval when a delay occurs in work of the work category in the work robot. And
The main controller is
When the information is notified by the notification unit, among the plurality of robot controllers, a robot controller provided in a work robot located downstream in the work transfer direction from the work robot in which work is delayed in work classification A robot system comprising: a reallocation unit that executes reallocation processing for reallocating unexecuted work categories in the order of work with n as an upper limit. An auxiliary work robot arranged adjacent to the work robot located on the most downstream side in the work transfer direction;
An auxiliary robot controller provided in the auxiliary work robot,
The auxiliary robot controller has an auxiliary processing unit that causes the auxiliary work robot to execute the work of the assigned work category,
The re-allocation unit allocates to the auxiliary robot controller the work divisions that have been allocated to a robot controller provided in a work robot located on the most downstream side in the work transfer direction and have exceeded the upper limit of n. The robot system according to claim 1. The main controller has a detection unit that detects a work robot that is out of work among the plurality of work robots,
The allocating unit performs the allocation process on a robot controller provided in a work robot other than the work robot detected by the detection unit and disabled from the work robot among the plurality of robot controllers. The robot system according to claim 1 or 2.

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