JPH0790479B2 - Robot work tracking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot work follower, and more particularly to a plurality of continuous conveyors that continuously convey works, each of which makes the robot follow the robot. It relates to a device capable of

[Prior art]

Recently, in manufacturing factories, various work robots are made to follow a human-supported continuous conveyor (hereinafter also simply referred to as "conveyor") that has been laid conventionally, and the work on the conveyor and the robot are relatively moved. The robot application technology based on the follow-up specification is being actively studied in order to reduce the equipment cost so that the robot can play back in the stopped state.

[Problems to be solved by the invention]

However, the follow-up device which has been conceived up to now and partially realized is basically incapable of causing the robot to follow only one conveyor.

Therefore, when the robots are made to follow the plurality of conveyors respectively, it is necessary to install the robot and the follow-up device for each conveyor, which causes a problem that the equipment cost increases.

The present invention has been made to solve such a problem, and an object thereof is to make it possible to follow a plurality of continuous conveyors with a single robot and follow-up device.

[Means for solving problems]

Therefore, the robot work following device according to the present invention is
As shown in FIG. 1, a plurality of continuous conveyors for continuously transferring the works 100 and 101 at a predetermined transfer speed.
A traveling device 105 provided between 102 and 103 for traveling the robot 104 along each conveyor 102, 103, and the traveling device 10
5, the work detectors 106, 107 for detecting the works 100, 101 conveyed by the respective conveyors 102, 103, the conveyor speed detectors 108, 109 for detecting the conveyance speed of the respective conveyors 102, 103, and the work detectors 106, 107 detect the works. When following, the tracking control device 1 that controls the traveling speed of the traveling device 105 based on the conveyance speed of the conveyor that conveys the work.
10, and when the work detectors 106 and 107 detect a plurality of works at the same time, the follow-up control device 110 performs control based on the carrying speed of the conveyor that selects any one of the works and carries the work. When the robot work for the one work is completed, the follow-up control device causes the robot to move to a position along with the next work selected from among the works that have not yet been selected. Selection means 111 for moving the robot to cause the follow-up control device to perform control based on the transfer speed of the continuous conveyor that transfers the next work.
It is composed by.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent drawings.

FIG. 2 is an equipment configuration diagram showing an embodiment of the present invention.

In the figure, reference numerals 1 and 2 denote continuous conveyors laid in parallel with each other, and the vehicle bodies 3 and 4 as works are respectively conveyed at predetermined transfer speeds (both transfer speeds may be the same or different). It is continuously conveyed in the X direction shown.

These conveyors 1 and 2 are adapted to be driven by a conveyor motor and a driving force transmission means (not shown), and the output shaft of each conveyor motor has a conveyor speed for detecting the conveyor speed of each conveyor. As the detector, for example, a pulse generator (the frequency of the output pulse is proportional to the carrier speed) described later is provided.

A traveling device 5 is provided between the conveyors 1 and 2,
Robot 6 installed on traveling base 5a along conveyors 1 and 2
Is run only for the section S.

Traveling pedestal 5a of the travel device 5 is summer as traveling in the arrowed X ₁ or X ₂ direction via the ball screw or the like (not shown) by the rotation of the travel motor 7, the traveling speed and the traveling position, the traveling It is detected by a tachogenerator 8 and a pulse generator 9 attached to the output shaft of the motor 7.

Incidentally, the home position of the traveling pedestal 5a is set in the vicinity of the traveling end of the arrow X ₂ direction. The robot 6 is to perform play back work such as welding, assembly, and inspection of the painted surface on the vehicle bodies 3 and 4.

10 and 11 are work detectors, which are the traveling bases 5a of the traveling device 5.
It is installed on the top and detects the presence of the car bodies 3 and 4, which are works, respectively. As the work detectors 10 and 11, for example, reflective photoelectric sensors can be used.

Next, FIG. 3 is a block diagram showing the configuration of the control system system excluding the robot control system.

In the figure, reference numeral 12 is a control unit constituted by a microcomputer or the like, and in addition to the illustrated start command ST, traveling position command CM, selection command SL, and reset command RE, a controller not shown in the robot 6 is provided. Outputs a robot start command, etc. Also,
The work detection outputs A and B are input to the control unit from the work detectors 10 and 11 described above, and a work completion signal or the like is input from the robot controller.

Reference numeral 13 denotes a traveling position command device, which sequentially outputs the current position Px of the traveling pedestal 5a from a pulse counter 15 described later to the adder 14 of the next stage when the start command ST is input from the control unit 12 and controls When the traveling position command CM is input from the section 12, the current position Px from the pulse counter 15 and the position command ΔCM from the pulse counter 24 are invalidated, and the traveling position command CM is input.
Only CM is output to the adder 14.

The adder 14 outputs Px + ΔCM or CM.

A pulse counter 15 counts up or down the pulses from the pulse generator 9 according to the rotation direction of the traveling motor 7 to detect the current position Px of the traveling pedestal 5a.

16 is a deviation register, and the position command Px + from the adder 14
The deviation ΔX between ΔCM or CM and the current position Px from the pulse counter 15 is always written.

Reference numeral 17 denotes a loop gain device, which performs D / A conversion of the deviation ΔX from the deviation register 16 and amplifies the converted value with an optimum position feedback back loop gain to obtain a speed command voltage value.
Output Vx.

Reference numeral 18 denotes a subtracter, which outputs a difference voltage obtained by subtracting the actual speed voltage value FVx of the traveling pedestal 5a detected by the tachogenerator 8 from the speed command voltage value Vx from the loop gain unit 17.

Reference numeral 19 denotes a servo amplifier, which supplies a drive current corresponding to the difference voltage from the subtractor 18 to the traveling motor 7 to control the rotation speed and the rotation amount of the traveling motor 7.

20 and 21 are pulse generators that detect the conveying speed of the conveyors 1 and 2, respectively, and the pulse generator 20 is the conveyor 1
The pulse signal PA of the frequency corresponding to the rotation speed of
The pulse generator 21 outputs a pulse signal P _B having a frequency corresponding to the rotation speed of the conveyor 2.

22 and 23 are selectors, which select output of the pulse signal PA and the detection output A of the work detector 10 (the detection signal of the vehicle body 3 on the conveyor 1) when the selection command SL from the control unit 12 is "1", for example. However, when SL is "0", the pulse signal P _B and the detection output B of the work detector 11 (the detection signal of the vehicle body 4 on the conveyor 2)
Is output selectively.

Reference numeral 24 denotes a pulse counter, which is controlled by the reset command RE from the control unit 12 and the detection output A or B from the selector 23 (both are the change points of rising or falling of the output) input via the OR circuit 25. The count value is reset and the pulse signal P _A or P _B from the selector 22 is counted to generate a position command ΔCM for tracking.

Next, the operation of this embodiment will be described with reference to FIGS. 4 to 6.

FIG. 4 shows a micro computer (hereinafter,
It is a processing flow figure of the program which a "microcomputer" calls.

First, when the control unit 12 and a robot control device (not shown) are activated while the traveling base 5a of the traveling device 5 is returned to the origin position, the control unit 12 and the microcomputer of the robot control device perform the required initialization processing. After performing the above procedure, each waits at a predetermined slap of a main routine (not shown).

Then, after that, the microcomputer of the control unit 12 performs the following (I) to (IV)
Different processing is performed depending on the case.

(I) When the vehicle body 3 on the conveyor 1 is conveyed first, the detection output A from the work detector 10 is input to the control unit.

The microcomputer of the control unit 12 executes the follow-up control program shown in FIG. 4 at regular intervals in a main routine (not shown), and checks that the detection output has been input in the work detection check process of the first step. Then, it checks whether or not the detection outputs A and B are input at the same time.
Since only one detection output is input now, check whether the detection output is A or not.
Check whether or not the work has been completed depending on whether or not a work completion signal from a robot controller (not shown) has been input, and if the work is not yet completed, the travel position command device 13 in FIG. Immediately after the start command ST is output, a follow-up process of outputting the selection command SL (for example, "1") for selecting the pulse signal P _A and the detection output A to the selectors 22 and 23 is performed, and then the process returns to the main routine. .

By this follow-up process, the traveling position command device 13 starts to output the current position Px from the pulse counter 15 (which initially indicates the origin position of the traveling pedestal 5a) to the successive adder 14, and the pulse counter 24 Is reset by the detection output A via the selector 23 and the OR circuit 25, and then the selector 22
The pulse signal P _A of the frequency corresponding to the conveying speed of the conveyor 1 input via the counter is counted, and the count value is output as the position command ΔCM. Therefore, the adder 14 successively outputs Px + ΔCM. It will output.

Therefore, the deviation register 16 always stores the deviation ΔCM of ΔCM.
Since X is always written, the loop gain unit
17, by the action of the subtracter 18 and the servo amplifier 19, the traveling motor 7 is rotated at a speed corresponding to the change of ΔCM, that is, a speed synchronized with the conveying speed of the conveyor 1, whereby the traveling pedestal 5a is rotated. The installed robot 6 is the conveyor 1
It will follow you.

The microcomputer of the control unit 12 performs the follow-up process described above,
A robot start command is output to a robot controller (not shown) at a predetermined timing when the main follow-up control is repeatedly executed after returning to the main routine, and the robot 6 shown in FIG. 2 is caused to perform a playback operation.

Then, while the robot 6 is performing play back work on the car body 3, the work detection check process, the A / B simultaneous input check process, the A input check process, the work completion check process of the car body 3 and the main follow-up process are performed in a loop. Is repeated until the work completion signal is input from the robot controller.

When the work completion signal is input from the robot controller, the main routine (not shown) outputs the traveling position command CM indicating the origin position to the traveling position command device 13 and the reset command RE to the pulse counter 24 via the OR circuit 25. Is output.

Then, the output ΔCM of the pulse counter 24 becomes “0”,
Since the adder 14 outputs the traveling position command CM as it is, the deviation ΔX of CM-Px is sequentially written in the deviation register 16, whereby the traveling pedestal 5a on which the robot 6 is installed is located at the origin position. And waits for detection of the next vehicle body 3 or 4.

When the work completion signal is input during execution of the main routine and the follow-up control routine of FIG. 4 at a constant cycle, the work completion check process proceeds to the check process of whether or not the detection output is B, and The process returns to the main routine, and if the detection output A is not input in the process of returning to the origin, the process directly returns to the main routine through the first work detection check process.

(II) When the vehicle body 4 on the conveyor 2 is conveyed first When the detection output B is input from the work detector 11, the B input check process in the follow-up control routine of FIG. The detection output is B and the vehicle body 4
On the condition that the work for is not completed, the start command ST is output to the traveling position command device 13 in FIG. 3 and the selection command for selecting the pulse signal P _B and the detection output B to the selectors 22 and 23. After performing a tracking process that outputs SL (for example, "0"), the process returns to the main routine.

As a result, the traveling pedestal 5a provided with the robot 6 shown in FIG. 2 follows the conveyor 2 by the same operation as in the case of (I).

(III) When the other vehicle body is detected during the return to the original position, for example, as shown in FIG. 5, after the robot 6 completes the work on the vehicle body 3, the vehicle body 4 is moved while returning to the original position. When the work detector 11 has detected it, when the follow-up control routine of FIG. 4 is executed, the follow-up process for the vehicle body 4 is immediately executed, and the return process that has been performed so far is stopped.

When returning to the origin position, if the same vehicle body as the one that finished last time flows, the same processing as the previous time is repeated, provided that the detection output corresponding to the previous vehicle body has been cut off once. And

(IV) When the car bodies 3 and 4 on the conveyors 1 and 2 are conveyed at the same time Following the first work detection check process and the simultaneous A and B input check process of FIG. 4, the car body 3 should be prioritized. ,
Check whether the work on the vehicle body 3 is completed,
If not completed, the same follow-up process as in (I) for the vehicle body 3 is performed, and then the process returns to the main routine, whereby the robot 6 first follows the conveyor 1.

Then, when a work completion signal is input from the robot control unit, the traveling position command CM necessary for the traveling pedestal 5a on which the robot 6 is installed to come out to the head of the vehicle body 4 on the conveyor 2 side is set to the third position.
The forward processing output to the traveling position command device 13 in the figure is performed.

When the traveling pedestal 5a is located at the head of the vehicle body 4, the work detector 11 waits for the vehicle body 4 to be detected, and if detected, the conveyor 2 is followed by the same processing as in (II).

However, in this case, the workpiece detector 10 is the same vehicle body 3 again.
However, since the work on the vehicle body 3 has already been completed at this time, this detection is ignored.

When the detection outputs A and B are input at the same time, the work priority order is set to the one with the faster conveyor transport speed.
It is also possible to allow time to complete the work of the vehicle bodies 3 and 4 of the stand.

In that case, the pulse signal P from the pulse generators 20 and 21
Count _A and P _B at regular time intervals, and
_A counter circuit for detecting the conveying speeds V _A and V _B of 1 and 2 is provided so that the detected conveying speeds V _A and V _B are input to the control unit, and the processing shown by the broken line in FIG. 4 is performed. Instead of the step, the processing step surrounded by a broken line in FIG. 6 may be executed.

That is, in the case of simultaneous input of A and B, first check whether or not one work is completed, and perform a comparison check of the conveyor speeds V _A and V _B of the conveyors 1 and 2 on condition that the work is not completed. , V
_{If A} > V _B, follow the processing for conveyor 1 (vehicle body 3) by V
_{If A} <V _B, follow processing for the CT conveyor 2 (vehicle body 4) is performed.

When one work is completed, a forward process similar to that shown in FIG. 4 is carried out, and then one remaining work is carried out by the process similar to that shown in FIG. 4 after the A-input check process.

In the embodiment described above, the example in which the robots are made to follow the two continuous conveyors has been described. For example, in the equipment shown in FIG. 2, a suspension type continuous conveyor above the traveling device 5 is used. In the case where the above is installed, it is also possible to make the robots follow the works conveyed by the three continuous conveyors including them so that the required work can be performed. .

〔The invention's effect〕

As described above, according to the robot work follow-up device of the present invention, even when a plurality of works are simultaneously detected by the work detector, one of the works is selected and the selected work is conveyed. It is possible to cause the follow-up control device to perform control based on the transport speed of the tiny conveyor, and thereafter, based on the transport speed of the next work by moving the robot to a position that follows the next work selected. Control can be performed by the follow-up control device. Further, since one robot and the follow-up device can make the robot follow a plurality of continuous conveyors, the robot can be efficiently installed on the line with the follow-up specification without increasing the equipment cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the configuration of the present invention, FIG. 2 is a facility configuration diagram showing an embodiment of the present invention, FIG. 3 is a block diagram showing the configuration of a control system system excluding a robot control system, and FIG. FIG. 5 is a flow chart of a follow-up control routine executed by the microcomputer of the control unit 12 in FIG. 3, and FIG. 5 is a vehicle body 3, 4 and traveling device 5 which are also used for the explanation.
And FIG. 6 is a flow chart showing another example of the follow-up control routine. 1,2 ... Continuous conveyor 3,4 ... Car body (work), 5 ... Traveling device 5a ... Traffic pedestal, 6 ... Robot, 7 ... Traveling motor 8 ... Tach generator, 9 ... Pulse generator 10,11 ... Work detector , 12 ... Control unit 13 ... Travel position commander, 14 ... Adder 15, 24 ... Pulse counter 16 ... Deviation register, 17 ... Loop gain unit 18 ... Subtractor, 19 ... Servo amplifier 20, 21 ... Pulse generator (conveyor) Speed detector) 22,23 ... Selector, 25 ... OR circuit

Claims (1)

[Claims] 1. A traveling device, which is provided between a plurality of continuous conveyors that continuously convey a work at a predetermined conveying speed, and that travels a robot along a predetermined section along each of the continuous conveyors. Each of the traveling devices is provided with a work detector that detects a work conveyed by each of the continuous conveyors, and a conveyor speed detector that detects the conveyance speed of each of the continuous conveyors, and the work. When the detector detects a work, a follow-up control device that controls the traveling speed of the traveling device based on the conveyance speed of the continuous conveyor that conveys the work, and the work detector simultaneously detects a plurality of works. Occasionally, a continuous conveyor that selects one of these works and conveys that work (A) Cause the tracking control device to perform control based on the transport speed,
When the robot work for the one work is completed,
The continuous control unit moves the robot by the follow-up control device to a position along the next work selected from among the works not yet selected from the works, and conveys the next work. A robot work follow-up device, characterized in that the work-following device is configured by selecting means for causing the follow-up control device to perform control based on the convey speed of the conveyor.