JPH09101813A - Robot control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove useless time for interlock waiting by changing the operation contents of its own robot when the change of original scheduled operation described in a program is selected. SOLUTION: A CPU 14 reads out program information from a storage device 16 and estimates arrival time up to a succeeding interlock point through calculation. At the time of receiving preinterlock signals from all other robots, A CPU 14 compares the received signals with the preinterlock information of its own robot and selects whether the original scheduled operation described in the program is executed as it is or changed based upon a prescribed decision reference. When an operation change is selected, the CPU 14 corrects the speed pattern of a succeeding operation step so as to remove interlock waiting time. Or the CPU 14 selects execution enabled work from a previously prepared work list during the period of interlock waiting time and adds the found work to the original scheduled operation of the program to execute it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot control system, and in particular, in an interlock system between a plurality of industrial robots (hereinafter, simply referred to as robots), it automatically operates until an interlock release condition is satisfied. The present invention relates to the one in which the waiting time for interlock is eliminated by extending the positioning operation time of the lower priority robot or changing the operation schedule of the robot.

[0002]

2. Description of the Related Art In a system for performing interlock control between a plurality of robots of a teaching / playback system, for example, the positioning operation in the processing of the robot at the time of playback is generally determined by a parameter or a moving distance on a program.

At this time, when the robot is a multi-axis robot having a plurality of operation axes and performs simultaneous positioning processing for each axis, another axis is added in accordance with the axis having the longest movement time. By suppressing the deceleration time and maximum speed, simultaneous startup and simultaneous positioning are realized.

However, from the viewpoint of the robot-to-robot relationship, conventionally, no scheduling other than interlock processing has been performed, and the robots are activated at the same time and until a certain condition is satisfied at the interlock position. Holds that state (waiting for interlock). That is, in the conventional interlock control between robots, a certain set robot (a robot having a higher priority, which is hereinafter referred to as a reference robot) is set in order to avoid interference between robots. Other robots that may interfere with the operation / state (the robot with the lower priority.
It is called a peripheral robot. ) Is not allowed to enter the next process. For example, three robots M1, M2, M3
In the system of FIG. 2 consisting of robots M1 and M2
The robot M1 as the reference robot in the area where the robot M1 can interfere with each other, and the robot M1 as the reference robot in the area where the robots M1 and M3 can interfere with each other. Interlock completion signals a, b
Until the interlock completion signals a and b are input, the robots M2 and M3 cannot move to the next processing (see FIG. 5).

The concept of the reference robot and the peripheral robot in the interlock is relative,
The same robot may become a reference robot in relation to one robot, and may become a peripheral robot in relation to yet another robot.

[0006]

However, in such a conventional interlock system, when there is a peripheral robot that holds the state until the interlock completion signal is output from the reference robot, It can be said that the peripheral robot is wasting time because it does not perform any work until the interlock completion signal is input and is only waiting for the input of the interlock completion signal.

In order to eliminate the dead time due to the interlock wait, the peripheral robot should correct the speed pattern of the positioning operation so as to eliminate the interlock wait time, or perform other work that can be executed during the interlock wait time. Since it is effective to execute it additionally, it is desirable to construct a system capable of automatically performing such processing.

The present invention has been made in view of the above problems in an interlock control system for a robot, and an object of the present invention is to provide a robot control system in which there is no dead time due to waiting for an interlock.

[0009]

In order to achieve the above-mentioned object, the invention according to claim 1 is described in a program in a robot control system which performs each work while interlocking between a plurality of robots. An estimation unit that estimates the arrival time to the interlock point based on predetermined information, and a pre-interlock signal that includes the arrival time estimated by the estimation unit, the identification number of the self, and the information about the operation state A communication means for transmitting to the robot and also receiving the pre-interlock signal from another robot, and when receiving the pre-interlock signal from all the other robots by the communication means, the communication means transmits them to its own pre-interlock signal. Compared with the interlock signal, the originally planned operation described in the program is executed as it is, or Is a selection means for selecting whether to change the initially scheduled operation described in the program, and the operation of its own operation so that the interlock waiting time is eliminated when the operation change is selected by the selection means. A changing means for changing the contents is provided in each controller of the plurality of robots, and the plurality of robots are connected to each other through a common transmission line via the communication means.

[0010] In the present invention thus configured,
Each robot estimates the arrival time to the interlock point based on the predetermined information described in the program by the estimation means. Then, the pre-interlock signal, which is obtained by adding the identification number of the interlock point and the information regarding the operating state to the arrival time for each interlock point, is transmitted to another robot through the common transmission path by the communication means. Then, the selecting means, when receiving the pre-interlock signal from all other robots by the communication means, compares them with its own pre-interlock information,
Select whether to execute the originally planned behavior described in the program as it is or to change the originally planned behavior described in the program. As a result, when the former is selected, the originally scheduled operation described in the program is executed as it is, and when the latter is selected, the contents of its own operation are changed so that the interlock waiting time is eliminated by the changing means. After changing, the operation after the change is executed.

With respect to the contents of the processing by the changing means, the invention according to claim 2 is characterized in that the changing means moves the difference between the arrival times of itself and other related robots to the next interlock point. It is characterized in that the speed pattern of each operation step up to the next interlock point is corrected so that the waiting time of the interlock is eliminated by allocating the time.

Further, in the invention according to claim 3, the changing means selects a work which can be executed during the interlock waiting time from the work list created in advance,
It is characterized in that the requested work is added to the initially planned action described in the program.

Further, in the invention according to claim 4, the changing means sets the interlock waiting time in the work list created in advance based on the difference in the arrival time between itself and the other related robot. It determines if there is work available in the meantime, and if there is other work that can be done, it adds that work to the originally planned behavior described in the program, If not, the difference is assigned to each movement time to the next interlock point, and the speed pattern of each operation step to the next interlock point is corrected so that the interlock waiting time is eliminated. .

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a control system of a robot control system according to the present invention. Here, for simplification, only the control system of one of the plurality of robots is shown, but all other robots are basically configured in the same manner.

This robot control system is of the teaching / playback type, and is composed of a robot main body 10 and a robot controller 12 for controlling the robot main body 10 like the general one. The robot controller 12 includes a CPU 14, which is the basis of control, a storage device 16 such as a ROM and a RAM for storing various data such as a robot control program, robot language, teaching data, and parameters, and a remote control for teaching and reproducing the robot. A pendant control interface 20 connected to the teaching pendant 18, which is a device, a robot control interface 22 connected to the robot body 10, a data input device 24 for editing, and a data display unit 26.
Is provided. With the above configuration, the robot functions as a single unit. The robot controller 12 includes a peripheral device control interface 30 for controlling the peripheral device 28 in order to activate the peripheral device 28 or operate the robot body 10 in conjunction with the peripheral device 28. The present invention further includes a network 32 dedicated to robot interlock for communicating information (interlock information) regarding interlock control between robots, and this network 32 is a communication interface 34.
Are connected to each robot controller 12. In addition, this system is provided with a control command that can easily transmit the interlock information. The estimating means, the selecting means, and the changing means are constituted by the CPU 14, the communication means is constituted by the communication interface 34, and the common transmission path is constituted by the network 32.

The communication network 32 and its interface 34 are for interlocking to grasp the work status of other robots, and have a function of transmitting and receiving a pre-interlocking signal described later as interlocking information. doing. The communication interface 34 of each robot has a function of setting which station in the network 32 the own station corresponds to. Preferably, the station number is set on the network 32 from 0 consecutive stations.
It is set to n stations (n is the number of robots configuring the system). The station number set for each robot also has a meaning as an identification number (ID) unique to the robot.

As a method of communicating the pre-interlock signal through the network 32, for example, a station (robot) is cyclically transmitted / received to / from the next station (robot) in a preset order. More specifically, the robot set to 0 station is the master station, the robots of other stations are the slave stations, and 0 is set according to the station number.
It transmits and receives cyclically from the station. That is, the master station (robot) first writes the state of the robot of its own station in the interlock information using the communication interface 34, and transmits it to the next station (robot) via the network 32. Upon receiving this, the slave station reads the robot status of the other station in the interlock information, writes it in the interlock information storage area of the storage device 16, and writes the robot status of its own station in the interlock information and writes it in the other station. It will be sent to the next station together with the robot status. After that, each station executes the same processing as that of the slave station, and the interlock information is returned to the master station again. The master station reads the status of the robot of the other station in the returned interlock information, writes it in the interlock information storage area of the storage device 16, and writes the current status of the robot of its own station in the interlock information. The contents are updated and sent to the next station together with the robot status of other stations. After that, each of the master station and the slave station repeatedly performs the above-mentioned transmission / reception, so that the robot of each station can refer to the state of the robot of another station from the interlock information storage area of its own storage device 16 at any time. .

The pre-interlock signal is constantly communicated between the robots by the above-mentioned communication method. That is,
When communication is possible, the pre-interlock signal is transmitted and received sequentially even when the robot is operating. In this case, the operation change timing can be arbitrarily set in advance by programming.

Further, the pre-interlock signal is composed of a robot ID, an operation state and an arrival time which will be described later. The peripheral robot in the interlock grasps the current state of the reference robot from the data of the robot ID and the operation state, and from the arrival time data,
It is possible to know the time until the reference robot reaches the interlock release point (the point at which the operation step requiring the interlock is completed). According to the present invention, the peripheral robot in the interlock changes the content of its own operation based on the data so as to eliminate the interlock waiting time in relation to the reference robot.

The interlock control itself between robots is performed by an interlock command on a program created for each robot in advance, as is the case with general control. That is, a robot having a high priority (reference robot) and a robot having a low priority (peripheral robots) are determined in advance among the robots in the area where they interfere with each other, and the interlock command indicates the ID and operation state of the reference robot. By setting, it is configured that the peripheral robot cannot enter the next process until the reference robot makes a transition to the set state (for example, until a point that is a condition for releasing the interlock is reached). With this, when the peripheral robot reaches the interlock release point (point held until the interlock is released), it is confirmed from the ID and operation state data that the reference robot has reached the interlock release point. After that, it becomes possible to move to the next processing.

The CPU 14 has the functions of the estimating means, the selecting means, and the changing means as described above.
Each function will be described in detail later, but here,
The outline of them will be described. First, the CPU 14 as an estimation means reads out predetermined information from a program stored in the storage device 16, and based on this information, the next interlock point (interlock release point in the reference robot and interlock target in the peripheral robot). The arrival time to the concept including both release points) is estimated by calculation. Further, the CPU 14 as a selection means
When it receives pre-interlock signals from all other robots, it compares them with its own pre-interlock information (especially comparing the arrival time data from the associated robot with its own arrival time data). ), According to a predetermined criterion, the originally planned motion described in the program is executed as it is (mainly when the reference robot is programmed in the fastest mode), or the originally planned motion described in the program. Select or change (mainly for peripheral robots). Further, a CPU as a changing means
When the operation change is selected, 14 specifically performs a process of changing the content of its own operation so that the interlock waiting time is eliminated. There are basically two types of contents of the change processing. One is to correct the speed pattern of each operation step up to the next interlock released point so that the interlock waiting time is eliminated. More specifically, the acceleration / deceleration time is extended and the maximum speed is suppressed. Another is to select the work that can be executed during the interlock waiting time from the work list created in advance, and to specify the requested work in the program originally planned. In addition to the operation, it is executed. Furthermore, as a derivative, a method that combines both,
For example, it is also possible to correct the speed pattern when other work cannot be additionally executed.

Hereinafter, some embodiments of the present invention will be described in more detail with reference to specific examples of a robot system. First, a case will be described with reference to FIGS. 2 to 5 in which a speed pattern of the motion of a robot is corrected when an interlock waiting time occurs in the robot. Here, FIG. 2 is a schematic diagram showing an example of a robot system, FIG. 3 is a flowchart showing the operation of each robot control system centered on a CPU, FIG. 4 is a flowchart of arrival time estimation processing in FIG. 3, and FIG. It is a motor waveform diagram which shows the operation content of each robot.

As shown in FIG. 2, this robot system has three robots M1, M2 and M3.
Each of 1 and M3 is composed of four motion steps, and the robot M2 is composed of three motion steps. The numbered points in the figure are teaching points, and each robot M
1 to M3 are positioned at each teaching point in the order of numbers. Then, in this teaching data, the robot M1
Between the teaching points 2 and 3 of the robot and the robot M
The operation step between the teaching points 2 and 3 of 2 is in the interference area, and the operation step between the teaching points 3 and 4 of the robot M1 and the operation step between the teaching points 3 and 4 of the robot M3 are the interference area. It is in. Here, in the relationship between the robots M1 and M2, the robot M1 is the reference robot (the robot M2 is a peripheral robot), and also in the relationship between the robots M1 and M3, the robot M1 is the reference robot (hence, the robot M3).
Is a peripheral robot. ). The interlock point at this time is the robot M1 and the robot M1.
The interlock releasing point of 1 is the teaching point 3, the interlock released point of the robot M2 is the teaching point 2, and in the relationship between the robots M1 and M3, the interlock releasing point of the robot M1 is the teaching point 4 and the robot M3. The interlock released point of is the teaching point 3. Therefore, when the robot M2 reaches the interlock released point 2, the robot M1 cannot move to the next operation step until the robot M1 reaches the interlock released point 3, and the robot M3 reaches the interlock released point 3. Then, the robot M1 cannot move to the next operation step until it reaches the interlock release point 4 (see FIG. 5, respectively). Further, the robots M2 and M3 have no risk of interference and have no relation to the interlock. In addition,
In the motor waveforms of the robots M2 and M3 in FIG. 5, the solid line shows the conventional motor waveform, and the dotted line shows the motor waveform according to the present invention.

Next, the operation will be described with reference to the flow charts of FIGS. When the power is turned on and the entire robot system is started, each robot
An interlock point (interlock release point or interlock released point) is searched with reference to its own program (including programs based on teaching results; the same applies hereinafter) (step S10) to see if there is an interlock point. It is determined (step S11). Normally, since the interlock point is taught in advance, it suffices to check the contents of the program for the processing of steps S10 and S11.

If there is an interlock point as a result of the determination in step S11, the process proceeds to the next step S12,
If there is no interlock point, immediately step S1
Proceed to 4. In the example of FIG. 2, all robots M1 to M3
Has an interlock point, so step S12
Will go on. The absence of interlock points means that the robot is not interlocking with all other robots.

In step S12, the arrival time to the interlock point (for each interlock point when there are a plurality of points) is estimated by calculation based on the predetermined information described in the program. This estimated arrival time is an estimate of the time to reach the interlock point when the robot is supposed to move at the fastest speed, and estimates the arrival time of the interlock point that is related to other robots. Not a thing. The method of estimating the arrival time to the interlock point is, for example, the number of steps from the current operation step to the interlock step (operation step to reach the interlock point),
It is estimated by a predetermined calculation from each moving distance, presence of interlock input, incidental processing, maximum speed parameter, and acceleration / deceleration parameter.

The specific procedure of the arrival time estimation processing in step S12 is as shown in the flowchart of FIG.
Note that this processing is performed by the CPU 14. First, the number of steps from the current operation step to the interlock step is calculated from its own program, and each moving distance, presence / absence of interlock input, and presence / absence of auxiliary processing are extracted (step S20).

Next, input an interlock to the extracted information,
It is checked whether there is any supplementary processing (step S2).
1). Here, the interlock input is in the relationship with the peripheral device 28, and is, for example, a case where the input wait state occurs in the relationship with the transfer machine. Further, the incidental processing is processing performed by itself, for example, ON / OFF of the valve.

YES as a result of the determination in step S21
If so, it is determined whether the existing interlock input or auxiliary processing is self-contained or similar to self-contained (step S22). Here, the case of self-sufficiency is an operation that is completed by itself without any other influence such as ON / OFF of a valve, and the case similar to self-sufficiency is, for example, the return limit of a transfer machine or a cylinder. The operation of the peripheral device 28 is not affected by other robots such as waiting.

If NO as a result of the determination in step S22, that is, if the existing interlock input or auxiliary processing is not self-completion or similar to self-completion, the arrival time depends on the input timings thereof. Moreover, since the input timing cannot be set in advance, the present estimation process is immediately stopped (step S23) and the process returns.

On the other hand, if the result of the determination in step S22 is YES, that is, if the existing interlock input or auxiliary processing is self-completion or similar to self-completion, those operations consider the input timing and the like. Since it is not necessary to perform the processing, the processing can be performed at any time, and the processing time can be arbitrarily set.
At 24, the total time for interlock input / accompanying processing is set. This process is performed, for example, by setting each process time of the interlock input / accompanying process in advance and adding them. Actually, each time of interlock input / accompanying processing is set to a value that is the fastest.

If there is no interlock input or incidental processing as a result of the determination in step S21, or step S24
When the processing of step 1 is completed, the maximum speed parameter and the acceleration / deceleration parameter are extracted from the parameter table (step S
25).

In the next step S26, the operation time required for positioning to the interlock point is first calculated for each operation step by the respective movement distances extracted in step S20 and the maximum speed parameter and acceleration / deceleration parameter extracted in step S25. It is calculated by adding the calculated values from the above.

Finally, the total time of the interlock input / accompanying processing obtained in step S24 is added to step S26.
The operation time required for positioning to the interlock point obtained in step S2 is added, and the added time is set as the estimated arrival time at the interlock point (step S2).
7) Return.

When the arrival time to the interlock point is estimated by the above procedure, this estimated arrival time is transmitted to another robot through the communication interface 34 and the network 32 (step S13). As described above, the estimated arrival time is transmitted by writing a pre-interlock signal, which is obtained by adding the robot ID and the operation state data to the estimated arrival time data, in the interlock information.

When the pre-interlock signals of each robot are cyclically transmitted and received as described above and the pre-interlock signals from all the other robots are received (step S14), the input pre-interlock signals of the other robots are received. Comparing the signal and its own pre-interlock signal,
It is selected whether to proceed to step S16 (for reference A) or to proceed to step S17 (for reference B) (step S15). Note that this processing is also performed by the CPU 14.

Specifically, for example, after the robot ID is extracted from the pre-interlock signal of another robot, the robot related to the self regarding the interlock is selected by looking at its own program (determination of the relevance of the robot). ).
If there is no interference area and no relation with any robot, it is determined that there is no relevant robot, and the process proceeds to step S16 (reference A1). If there is a related robot, the robot determines whether the robot is a reference robot or a peripheral robot in relation to the related robot, and compares the estimated arrival times of the robots. As a result, when the self is a peripheral robot (for example, the robots M2 and M3 in FIG.
In reference to the reference robot (see, for example, robot M1 in FIG. 5), the estimated arrival times t2 and t4 to the next interlock release point of the self are estimated to the corresponding interlock release point of the reference robot. Arrival time t
1 and t3 earlier than (t2 <t1, t4 <t3
), Since an interlock waiting time occurs for itself, the process proceeds to step S17 in order to eliminate it (reference B),
If it is late, the interlock waiting time does not occur for itself, so the process proceeds to step S16 (reference A2). If the robot itself is the reference robot, it is not affected by the peripheral robots, so the process proceeds to step S16 (reference A3
).

If step S16 is selected, the originally planned operation described in the program is executed as it is. In other words, the robot executes the program in the fastest mode as scheduled.

On the other hand, when the step S17 is selected, the peripheral robot uses the data of the arrival time, the number of steps, and the moving distance so as to eliminate the interlock waiting time. , Acceleration / deceleration constant) is changed (correction of positioning operation), and the program is executed with the changed contents. To change the speed pattern, assign the difference between the estimated arrival time of the reference robot and the estimated arrival time of your own to the movement time of each operation step to your next interlock release point, and extend the acceleration / deceleration time This is done by realizing speed control. There are various concrete methods, such as determining the maximum speed / acceleration / deceleration constant so that the movement time ratio (motion ratio) of each operation step does not change, but whichever method is used. , It can be adjusted automatically by programming beforehand. Note that this processing is also performed by the CPU 14.

As an example of a method of determining that the operation ratio does not change, there is, for example, the following method. First, a moving amount table for each maximum speed and each acceleration / deceleration constant is created in advance. Then, in the actual processing, the operation time (moving time) Tk 'after the change of each operation step is obtained by the following proportional expression. Here, k: number of each operation step up to the interlock release point Tk ': operation time after change of operation step k Tk: (normal) operation time before change of operation step k T0': after change Interlock release point arrival time (= estimated arrival time to interlock release point of the reference robot) T0: interlock release point arrival time before change (= estimated arrival time to interlock release point of self) , The arrival time difference Δ (= T0′−T0) corresponds to the interlock waiting time. Further, as described above, the operation change timing (from which operation step is changed) can be arbitrarily set by programming. Finally, the maximum speed and the acceleration / deceleration constant are determined for each operation step from the movement amount table and the previously calculated operation time Tk 'of each operation step so that the movement amount does not change.

Then, in step S18, it is determined whether or not the interlock point has been reached. If the interlock point has not been reached, the process returns to step S12. If the interlock point has been reached, the process returns to step S10 and subsequent steps. repeat.

Each of the robots M1 to M when the interlock control is performed using the pre-interlock signal as described above
The motor waveform of 3 is shown in Fig. 5. For the peripheral robots M2 and M3, the maximum speed and acceleration / deceleration constants are set for each operation step up to the point where the interlock is released, as indicated by the dotted lines. The positioning operation is corrected to suppress the interlock waiting time.
The horizontal axis of the motor waveform diagram is time, and the vertical axis is current or speed command. Here, for simplification, the stop time at each teaching point is omitted. Also, as described above, the pre-interlock signal is always communicated, but here,
For simplification, each of the robots M1 to M3 starts up from the teaching point 1 (pre-interlock signal c)
Is shown.

Therefore, according to the present invention, since the waiting time for interlock is eliminated, the dead time due to waiting for interlock is eliminated. Further, since the mechanical loss of the robot is reduced by extending the acceleration / deceleration time and suppressing the maximum speed, the life cycle can be extended. Further, the extension of the acceleration / deceleration time reduces the inertia and the required torque (current), so that the running cost can be reduced by reducing the power consumption. That is, since the maximum speed and the acceleration / deceleration constant are suppressed, the load on the mechanism and the power consumption are reduced, and the positioning operation with less mechanical and electrical loss becomes possible.

Next, as another example, with reference to FIGS. 6 to 8, a case will be described in which another work is additionally executed when an interlock waiting time occurs in a certain robot. Here, FIG. 6 is a schematic view showing another example of the robot system, and FIG.
Is a flowchart showing the operation of each robot control system centering on the CPU, and FIG. 8 is a motor waveform diagram showing the operation contents of each robot.

Here, as shown in FIG. 6, consider a robot system composed of two robots M1 and M2. Each of the robots M1 and M2 is composed of four operation steps (teaching points 1 to 4), and a position P for performing another predetermined work is set in the robot M2 when possible. In this teaching data, the operation step between the teaching points 3 and 4 of the robot M1 and the operation step between the teaching points 2 and 3 of the robot M2 are in the interference area. Here, the robot M1 is a reference robot and the robot M2 is a peripheral robot. At this time, the interlock release point of the robot M1 is the teaching point 4, and the interlock release point of the robot M2 is the teaching point 2. Therefore, when the robot M2 reaches the interlock release point 2, the robot M1 moves to the interlock release point 4
It is impossible to move to the next operation step until the point reaches (see FIG. 8). In the motor waveform of the robot M2 in FIG. 8, the solid line shows the conventional motor waveform, and the dotted line shows the motor waveform according to the present invention.

According to the present invention, when a waiting time for interlock occurs in the peripheral robot, if there is any work other than the scheduled work during the waiting for the interlock, that work is executed. The work list of is created in advance. The work (incidental processing, operation) other than the originally intended operation includes, for example, automatic chip dressing processing in a spot welding robot, chip replacement, parts delivery, and welding of other robot areas. For these tasks, select ones that do not interfere with other robots. The work list describes the work contents and the required time. Here, as an example, the target work is a chip dress. The tip dressing work is performed at the teaching point P (see FIG. 6).

Next, the operation will be described with reference to the flowchart of FIG. 7, but here, in order to avoid duplication of description, processing different from that of FIG. 3 will be mainly described. In the present proposal, steps S37 to S39 are used instead of step S17 of FIG.
Execute That is, as in the case of FIG. 3, in steps S30 to S35, after the arrival time to the interlock point is estimated and the pre-interlock signal is transmitted, the pre-interlock signals of all the other robots received are received. Is compared with that of self, and step S36
To (step A37) or step S37 (case B). In the comparison calculation (subtraction), the source (comparison source) and the destination (comparison target) can be set. For both the source and the destination, the estimated arrival time of the peripheral robot, the estimated arrival time of the reference robot, It is based on another factor that is not considered in the estimated time, such as setting a reference time (for example, throwing in a product), and an arbitrary fixed value (for example, 10
Seconds)) can be selected.

When the route toward the step S37 is selected as a result of the comparison calculation of the pre-interlock signal in the step S36, the processing process is changed. The method of changing the processing process is a conditional branch or a call of a child process (subroutine).

Specifically, first, the peripheral robot analyzes the pre-interlock signal to determine whether other work is possible (step S37). Specifically, for example,
The difference .DELTA.t (= t5 -t6) between the estimated arrival time of the reference robot (see, for example, the robot M1 in FIG. 8) and the estimated arrival time of self (see, for example, the robot M2 in FIG. 8) is set to a predetermined value (for example, 5 seconds). ), It is determined that other work is possible if the difference Δt is a predetermined value (5 seconds) or more.

If it is determined in step S37 that another work can be performed, the interlock waiting time Δt of the interlock waiting time Δt is referred to while referring to the work content and the required time data from the work list created in advance. Select a work that can be executed in the meantime and execute the program for that work (step S
38). In the above example, when the tip dressing work can be performed during the interlock waiting time, the tip dressing work is performed in addition to the initially scheduled normal program. This eliminates dead time due to waiting for interlock (see FIG. 8). The solid line arrow d in FIG. 8 is the conventional interlock completion signal, and the broken line arrow e is the pre-interlock signal of the present invention.

If it is not determined in step S37 that another work can be performed, in order to eliminate the interlock waiting time, the positioning operation is corrected in the same manner as step S17 in FIG. 3 (step S39).

Therefore, according to the present invention, other work (incidental processing, operation) is performed during the interlock waiting time, so that the dead time due to the interlock waiting is eliminated. Further, since such other work can be randomly performed within the initially scheduled normal operation, the time of the work can be reduced. Furthermore, by constructing a certain series of processes with a set of child processes, it is possible to arbitrarily change the processes according to the progress of the work, and it is possible to give flexibility to the entire system.

In this example, the determination of the possibility of other work in step S37 is made by comparing the difference Δt of the estimated arrival times with a predetermined value. By comparing the difference Δt of the above with the required time of each work in the work list, the other work that can be executed immediately is obtained, and the positioning operation may be corrected only when there is no other work that can be executed. .

Further, the correction process of step S39 may be omitted, and if an interlock waiting time occurs, other work that can be executed may be performed during that time.

[0055]

As described above, according to the invention described in claim 1, when the interlock waiting time occurs, the contents of the operation are changed so that the interlock waiting time is eliminated. , The dead time due to waiting for interlock is eliminated.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, as a method of changing the operation content, the speed pattern is corrected to extend the acceleration / deceleration time and suppress the maximum speed. Since the positioning operation is performed with less mechanical and electrical loss, the life cycle is extended and the running cost is reduced to reduce the running cost.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, as the method of changing the operation content, other work is performed during the interlock waiting time. In addition to reducing the time of other work, by configuring a series of processes with a set of child processes, it is possible to change any process according to the progress of work, and to give flexibility to the entire system. .

According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, as a method of changing the operation content, if other work can be executed during the interlock waiting time, it is performed. If there is no other work, the speed pattern is corrected so that the interlock waiting time is eliminated, so that the dead time due to the interlock waiting is further reduced as compared with the invention according to claim 3.
It is possible to enjoy the respective merits of the described invention and the invention of claim 3.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control system of a robot control system according to the present invention.

FIG. 2 is a schematic diagram showing an example of a robot system.

FIG. 3 is a flowchart showing the operation of the control system centered on the CPU.

FIG. 4 is a flowchart of arrival time estimation processing in FIG.

FIG. 5 is a motor waveform diagram showing the operation contents of each robot.

FIG. 6 is a schematic diagram showing another example of a robot system.

FIG. 7 is a flowchart showing the operation of the control system centered on the CPU.

FIG. 8 is a motor waveform diagram showing the operation contents of each robot.

[Explanation of symbols]

 10 ... Robot main body 12 ... Robot controller 14 ... CPU (estimating means, selecting means, changing means) 32 ... Communication network (common transmission path) 34 ... Communication interface (communication means)

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Claims (4)

[Claims] 1. A robot control system for performing respective tasks while interlocking between a plurality of robots, and an estimating means for estimating a time required to reach an interlock point based on predetermined information described in a program, A pre-interlock signal including the arrival time estimated by the estimating means, an identification number of the self, and information about an operation state is transmitted to another robot, and the pre-interlock signal from the other robot is received. When the communication means and the pre-interlock signal from all other robots are received by the communication means, they are compared with their own pre-interlock signal, and the originally planned operation described in the program remains unchanged. Choose to execute or change the originally planned behavior described in the program Selecting means to perform, and when the operation change is selected by the selecting means,
Changing means for changing the contents of its own operation so that the interlock waiting time is eliminated, and the changing means are provided in each controller of the plurality of robots, and the plurality of robots are connected by a common transmission line via the communication means. A robot control system characterized by being connected to each other. 2. The changing means allocates a difference between the arrival times of the robot concerned and another related robot to each moving time to the next interlock point, and the next interlock is performed so that the waiting time of the interlock is eliminated. The robot control system according to claim 1, wherein a velocity pattern of each operation step up to a point is corrected. 3. The change means selects a work that can be executed during an interlock waiting time from a work list created in advance, and the requested work is initially scheduled to be described in the program. The robot control system according to claim 1, wherein the robot control system is added to an operation. 4. The change means, based on the difference in the arrival time between itself and other related robots, is there any work that can be executed during the interlock waiting time in the work list created in advance? If there is other work that can be performed, add that work to the originally planned behavior described in the program, and if there is no other work that can be performed, add the above difference to the next 2. The robot control system according to claim 1, wherein the speed pattern of each operation step up to the next interlock point is corrected so as to be assigned to each movement time up to the interlock point and the interlock waiting time is eliminated.