JPH0418609A - Sequence controller with positioning function for multi-axis - Google Patents

Abstract

PURPOSE:To execute positioning control and the control of a cam signal accurately by inputting the control operation complete signal of a multi-axis position control unit based on a control start signal and the cam signal of a guide motor from the multi-axis position control unit. CONSTITUTION:A programmable controller PC 26 as a sequencer and a position control unit 28 are provided corresponding to each working process area A. The PC 26 supplies a job signal corresponding to a car type and a common start signal synchronously with the conveyance of a car body from the area A. The unit 28 selects a position control data corresponding to the car body from a RAM 32 and according to a program set to a ROM 34 in advance, signals are supplied corresponding to respective inverters 40, the solenoids of respective solenoid valves and the PC 26. The inverters 40 supply rotation command signals for moving guide motors 16X and 16Y to target rotation positions and on the other hand, excitation control signals are supplied to the solenoids for setting a stored exciting state. Further, the cam signal having contents set in advance and the signal for announcing the completion of the control operation are supplied to the PC 26.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sequence control device having a multi-axis positioning function using a programmable controller.

(Prior Art) For example, on an automobile production line, a large number of work process areas are provided at appropriate intervals in the direction of conveyance of the car body as a workpiece, and in each of these work process areas, the work machines and Assembly, welding, painting, and other tasks are now performed in sequence using more advanced industrial robots. At that time, in each work process area, positioning pins are inserted into a plurality of positioning holes formed in the car body in order to position the car body carried by a conveyance means such as a floor shaft from the previous work process area. Insertion and engagement are commonly performed.

By the way, in such an automobile production line, the positions for forming the positioning holes in the car body as the workpiece differ depending on the car model, so when different car models are produced on the same production line, the positioning pins are formed in each work process area. will be controlled to position it in a position corresponding to the vehicle type, but this positioning work of the positioning pin is
Normally, sequence control is performed by a programmable controller (PC) along with control work of conveyance means such as a floor shaft.

In such a sequence control device using a PC, when controlling the positioning of the positioning pin at an arbitrary position depending on the workpiece, high positioning accuracy can be obtained, so the positioning control of the positioning pin is Although it is preferable to employ a servo control mechanism as the mechanism, it is economically disadvantageous because the servo control mechanism is expensive. Therefore,
In cases where high positioning accuracy of the positioning pins is not required, such as in automobile production lines, an induction motor is used as the drive motor for the positioning pins, and this induction motor is driven via an inverter device for economical reasons. Many positioning control mechanisms are in use.

(Problem to be Solved by the Invention) However, in a conventional sequence control device using a PC that employs an inexpensive positioning control mechanism for such an inverter device and an induction motor, it is difficult to rotate the induction motor via the inverter device. Since control was performed directly by a PC, the number of induction motors to be controlled increased, the number of axes to be controlled for positioning increased, and the program length of the PC became longer. This results in problems such as a significant increase in the monitoring cycle and a significant decrease in the positioning accuracy of the induction motor.

On the other hand, on automobile production lines, in order to prevent the positioning pins from interfering with the workpieces such as car bodies and working machines, the positioning pins are retracted and actuated within a specific movement range of the positioning pins, and There are cases where it is necessary to stop a specific operation of a robot, etc., but in such cases, conventionally, mechanical A cam mechanism and an electric cam mechanism incorporated into the PC program were used.

However, mechanical cam mechanisms have inherent problems such as their complicated structure, the trouble of changing the setting range, and the difficulty of making delicate adjustments. In the case of a cam mechanism, the settings are made in the program itself, so there is the problem that different programs must be created for different setting ranges and number of setting ranges, and it is difficult to set or change the range. There is a problem that specialized knowledge about programming is required, and when adopting an inexpensive positioning control mechanism for an inverter device and an induction motor as described above, the program length of the PC increases significantly, and the induction motor 6 The present invention was made against the background of the above circumstances, and its purpose is to inexpensively position an inverter device and an induction motor. This sequence control device has a multi-axis positioning function that employs a control mechanism, and is equipped with an electric cam mechanism that can set and change the rotation range and number of rotation ranges of multiple induction motors without changing the program. It is an object of the present invention to provide an induction motor capable of positioning each induction motor at its respective target rotational position with good positioning accuracy.

(Means for Solving the Problems) In order to solve these problems, the present invention has the following features:
As described above, the system is equipped with a plurality of induction motors driven through an inverter device, and the positioning work of rotationally moving each of the plurality of induction motors to a predetermined rotational position is sequentially controlled by a programmable controller along with other work. In the sequence control device according to the present invention, (a) a plurality of target rotational position storage area groups consisting of a plurality of storage areas capable of storing target rotational positions of the plurality of induction motors, respectively, are inputted, and for each of the plurality of induction motors. a storage means having a plurality of rotation range storage areas each capable of storing a plurality of rotation ranges, and (U) selecting a target rotation position storage area group from the storage means according to the content of a control operation start signal from the programmable controller; and outputs a rotation command signal to the inverter devices corresponding to the induction motors so as to rotate the induction motors corresponding to the target rotational positions stored in each area of the selected target rotational position storage area group. (c) Compare the plurality of rotation ranges stored in each rotation range storage area with the actual rotation position of each corresponding induction motor, and output a signal according to the comparison result. It was decided to provide a multi-axis position control unit including a rotation range determination means for outputting the rotation range.

(Operation and Effects of the Invention) In such a sequence control device, the programmable controller (PC) performs positioning control of each induction motor and detection of the rotation range of each induction motor for outputting a predetermined cam signal. While simply outputting a control operation start signal with contents corresponding to the target positioning work, it also outputs a control operation completion signal of the multi-axis position control unit based on the control operation start signal and the rotation range of the induction motor that requires the PC to be involved. It is only necessary to input the detection signal (cam signal) from the multi-axis position control unit, and the positioning control for each induction motor and the induction motor rotation range detection control for outputting the cam signal are substantially performed by the multi-axis position control unit. This will be done by In the multi-axis position control unit, both the positioning control and rotation range detection control are executed according to a program that is substantially independent of the PC program that performs control operations for other operations.

Therefore, even if the number of induction motors to be controlled and the number of cam signal output range settings for those induction motors increase, the program length for positioning control and rotation range detection control, and eventually the scan time of the program, will increase. As a result, although an inexpensive positioning control mechanism of an inverter device and an induction motor is adopted, it is possible to position a plurality of induction motors at each target rotational position with sufficient accuracy. At the same time, it becomes possible to detect the output range of the cam signal for each induction motor with good precision, and output the corresponding cam signal with good precision.

Moreover, in the sequence control device of the present invention, the target rotational position of each induction motor and the cam signal output range for each induction motor are stored in corresponding storage areas of the storage means provided in advance, Since data is read from these storage areas, the target rotational position of the induction motors and the cam signal output range for each induction motor can be set or changed simply by setting or changing the contents of these storage areas. Therefore, even an operator without specialized knowledge of programs can extremely easily change these settings Φ.

Further, in the present invention, since a plurality of memory areas for setting the output range of the cam signal are provided in advance for each induction motor, if the number of memory areas is within the set number, the memory areas can be stored. By setting the rotation range for the area, the set rotation range number can be changed without changing the program. Therefore, it is possible to save the effort of creating different programs for different set rotation range speeds, and it is also possible to eliminate the need for specialized knowledge about the programs when changing them.

(Example) Hereinafter, an example in which the present invention is applied to a sequence control device for an automobile production line will be described in detail based on the drawings.

FIG. 1 shows an automobile production line in which vehicle bodies are intermittently transferred in the direction of the arrow and predetermined operations are sequentially performed. Reference numeral 10 denotes a positioning bin, which is inserted into and engaged with a positioning hole formed in the vehicle body to position the vehicle body.
Four pieces are provided for each of (A+ to A11). These positioning bins 10 are each connected to a piston of a double-acting type cylinder 12, and can be moved to protrude or retract by switching operation of a corresponding electromagnetic switching valve (not shown).

As shown in FIG.
- mounted on a pole screw 18 by an induction motor 16X
By rotating x, it is guided by a guide rail 20X and moved in the X direction. In addition, the movable base 14
is mounted on the fixed base 22, and the guide rail 20 is rotated by the rotation of the pole screw 18Y by the induction motor 16Y.
Y, 20Y, and can be moved in the Y direction perpendicular to the X direction. Here, this allows each positioning bin 10 to be set to the preset X-
Each can be moved to an arbitrary position within the Y plane.

In addition, in FIG. 2, 24 indicates a gear.

By the way, in each work process area A of the production line,
As shown in FIG. 1, programmable controllers (PCs) 26 as sequencers are provided in correspondence with each other, and each PC 26 is provided with a position control unit 28 in correspondence with each other. .

The PC 26 is connected to other PCs 26 and the corresponding work process area A.
It is used to synchronize the work machines and industrial robots installed in the line, and to control the operation of the footshafts used to transport the car body. At the same time, a series of operations for the corresponding area A are sequence-controlled according to a preset program. When preparations for transporting the vehicle body are completed, this PC 26 sends a control operation start signal with content corresponding to the vehicle type of the vehicle body, for example, at a timing synchronized with the transport operation of the vehicle body from area A in the previous stage. The job signal and the common start signal for each vehicle type are transferred to the position control unit 2.
Supply to 8.

On the other hand, the position control unit 28, as shown in FIG.
The inverter devices 40 are connected to the encoders 44 provided in each of the induction motors 16X and 16Y, respectively, and the inverter devices 40 are connected to the encoders 44 provided in each of the induction motors 16X and 16Y at the I10 port 36, and the inverter devices 40 are connected to the They are respectively connected to the tilt side of the provided electromagnetic switching valve, the protrusion confirmation switch and the retraction confirmation switch provided on each cylinder 12, and a teaching box 42 as a setting device.

Here, in the RAM 32 of the position control unit 28, a fourth
As shown in (a) of the figure, there are a plurality of storage area groups M (M
1-M + 5) are provided, and each storage area group M has a memory area for each induction motor 4116X and 16Y, as shown in FIG. 4(b) and (C). Eight sets of target rotational position storage area groups MTR (MTR1
~MTRs) and 8 pairs of solenoid output storage areas 5ol for storing the excitation setting state of each solenoid.
8 pairs of solenoid output storage area groups SQL (SQL+"5OLa) consisting of (sol+~5ole) and 8 pairs of input setting state storage areas 5i (sil~5is) each capable of storing the input setting state of a predetermined input signal. Eight sets of setting input status storage area groups 5I (SI+ to 5I
a) is provided.

In addition to the position control data storage area group, the RAM 32 also stores each induction motor 16x, as shown in FIGS. 5(a) and 5(b).

8 sets of rotation range storage area groups CM (CM+ to CMa) consisting of two rotation range storage areas c (c+, C2) that can store the rotation ranges of the induction motors 16X and 16Y, respectively, corresponding to the induction motors 16Y. is provided.

When the job signal of the control operation start signal is input from the PC 26, the position control unit 28 selects a position control data storage area group M from the RAM 32 according to the type of vehicle represented by the job signal, and starts. When a signal is input, the data stored in each storage area m, s o I, s i of the selected storage area group M and the data stored in each storage area C of each rotation range storage area group CM are Based on this, the pulse signal from each corresponding encoder 44 and the confirmation signal from the confirmation switch of each cylinder 12 are used as feedback signals, and according to a predetermined program in the ROM 34,
Corresponding signals are supplied to each inverter device 40, the solenoid of each electric switching valve, and the PC 26.

Specifically, in each inverter device 40, each corresponding induction motor 16X, 16Y is connected to each corresponding storage area group M.
A rotation command signal for sequentially moving stepwise to the target rotation position stored in each storage area m of TR is supplied, and the solenoid of each electromagnetic switching valve is supplied with each storage area of each corresponding storage area group SQL. An excitation control signal for sequentially setting the solenoids in stages to the excitation state stored in sol is supplied to the PC 26, and each induction motor 16X
, 16Y, a cam signal with preset contents and a control operation completion signal indicating the completion of the control operation are supplied.

Note that the data in each storage area of the L RAM 32 is set in advance by the teaching box 42.

The rotation command signal supplied from the position control unit 28 to each inverter device 40 includes a forward/reverse rotation command signal, a low speed/reverse rotation command signal,
Each inverter device 40 supplies a drive signal corresponding to a rotation command signal from its position control unit 28 to each corresponding induction motor 16X, 16Y. And each induction motor 16X, 16Y.

The corresponding pole screws 18X and 18Y are rotationally driven by a drive signal from the inverter device 40, and each corresponding positioning pin IO is moved to a position corresponding to a rotation command signal from the position control unit 28. . Thereby, each positioning bin 10 is moved to the final target movement position through sequentially a plurality of positions set according to the vehicle type.

In addition, each electromagnetic switching valve receives an excitation control signal from the position control unit 28 and protrudes each corresponding cylinder 12.
Then, the positioning bin 10 is operated to protrude or retract according to the position set corresponding to the vehicle type.

Further, the PC 26 receives a cam signal from the position control unit 28, supplies a signal corresponding to the content of the cam signal to a working machine, an industrial robot, etc., and thereby connects the working machine, industrial robot, etc. with the positioning bin. Avoid interference with 10. For example, in order to prevent the arm of the robot from interfering with the positioning pin IO, a signal is supplied to the robot that prohibits the arm from protruding. Also,
The PC 26 receives the control operation completion signal from the position control unit 28 and starts the next operation.

In this example, the control operation in the position control unit 28 is specifically executed according to a flowchart as shown in FIG.

Hereinafter, the control operation in the position control unit 28 will be explained in more detail based on the flowchart shown in FIG.

When performing new positioning control of the positioning pin IO, first, in step Sl, it is determined whether or not a job signal is input from the PC 26. When the input of the job signal is confirmed, step S2 is subsequently executed, and it is determined which of the scheduled car types the contents of the job signal correspond to, and it is determined that the content of the job signal corresponds to the scheduled car type. A storage area group M is selected from the RAM 32.

When step S2 is completed, in the following step S3, it is determined whether or not a start signal is input from the PC 26. When the input of the start signal is confirmed, in the following step S4, each memory of the selected storage area group M is Area group MTR.

The read storage areas m, sol, and s+ of position control data in SQL and S I are m1sol) and sil, respectively.
is set to

When step S4 is executed, step S5 is subsequently performed.
is executed. In step S5, the setting data of successive storage area 5oil of each storage area group SQL set in step S4 is read out, and
An excitation control signal corresponding to the setting data is supplied to the solenoid of each corresponding electromagnetic switching valve. Then, in the subsequent step S6, it is determined whether each positioning pin 10 is in a state corresponding to the excitation control signal. Specifically, it is determined whether the state of the confirmation switch for the extended/retracted state of each cylinder 12 matches the stored contents of the corresponding input setting state storage area S (here, S+). be.

If the determination in step S6 is affirmative, step S7 is subsequently executed, and the target rotational position data in the storage area ml set in step S4 is read out. Then, in the subsequent step S8, a rotation command signal is supplied to each corresponding inverter device 40 according to the read target rotation position data, and thus each induction motor 16X
, 16Y are rotated according to the target rotational position data.

When step S8 is completed, step S9 is executed next, and for each induction motor 16X, 16Y,
It is determined whether or not the rotational movement position is within the rotation range stored in the corresponding rotation position storage area C of the RAM 32, and preset settings are made for each rotation range according to each determination result. At the same time, the supply of the cam signal to the PC 26 starts, and at the same time, the supply of the cam signal to the PC 26 is stopped. That is, for a rotation range for which the determination result is affirmative, a cam signal with content corresponding to that rotation range begins to be supplied to the PC 26, and for a rotation range for which the determination result is negative, the output state of the cam signal is non-conforming. It is set or maintained in a supply state.

Further, when step S9 is completed, step 310 is subsequently executed, and each induction motor 16X, 16Y
It is determined whether or not the target rotational position has been reached for each of the induction motors 16x, and it is determined that the target rotational position has been reached.

The rotation operation of 16Y is stopped. Then, in the following step Sll, it is determined whether all the induction motors 16X, 16Y have reached the target rotational position, and if the result of the determination is affirmative, step S12 is subsequently executed. If the result is negative, step 5
9 and below are repeated again.

In step S12, which is executed when the determination result in step Sll is affirmative, the target rotation position setting data read out in step S7 is stored in the final storage area m8.
In other words, it is determined whether the target rotational position of each induction motor 16X, 16Y is the final target rotational position. If the determination result is affirmative, step S13 is subsequently executed, and after a control operation completion signal is output to the PC 26,
Although the control operation is completed, if the determination result is negative, step S14 is subsequently executed, and each storage area group MTR, SQL.

The read storage areas m, sol, and si in SI are each switched to those in the next successive order.

The switched read storage area m, sol.

The above steps 55 and subsequent steps are repeated again for sf.

That is, if the read storage area m in step S7 is m+, in step S14 the read storage area m
, s o I and s i are m2 and 5, respectively
012, si2, and if m2, m3. Similarly, every time step S i 4 is executed, the read storage area m, sol, si is set to m3, sol:+si3.
so 13 , si3→m4.5o14.5i4−+−
---+mB, 5olB.

They are updated in the order of sia. And step S
If the read storage area m in step 7 is the final storage area m8, the judgment result in step S12 is affirmative, step S13 is executed, and after execution of step 313, one control operation is started from the PC 26. This completes a series of control operations based on the signal.

In addition, as is clear from the explanation of "2 series," in this example, step S2. S4. S7. S8. SIo.

314 corresponds to rotation command signal output means, and step S9
corresponds to the rotation range determining means.

As explained above, in this example, a PC 26 is provided for each work process area A of the automobile production line, and each induction motor 1 for moving and operating the positioning pin 10 is provided.
A plurality of operations for each area A including 6X and 16Y positioning control operations will be sequentially controlled by the PC 26, but in the sequence control device corresponding to each area A, the PC 26 as a sequencer When controlling the positioning of the induction motors 16X, 16Y (7) and controlling the output of cam signals for each induction motor 16X, 16Y, a control operation start signal consisting of a job signal and a start signal is simply output to the position control unit 28, while position control is performed. Only the cam signal and the control operation completion signal are input from the control unit 28, and the positioning control and the output control of the cam signal are substantially controlled by the PC.
The program is executed according to a block diagram of the position control unit 28 which is independent of the program of 26.

Therefore, as mentioned above, eight induction motors 16X, 16
Even if Y is controlled simultaneously, or if multiple cam signal output control ranges are set,
Furthermore, even in the case where the eight induction motors 16X and 16Y are operated in multiple stages up to the final target rotational position, the position for position control is determined by the program length of the control unit 28,
Furthermore, the scan time itself of the program can be suppressed to be sufficiently short, and as a result, each induction motor 16
The positioning accuracy of X, 16Y, and ultimately each positioning pin io is maintained sufficiently well, and the output accuracy of each cam signal is also maintained sufficiently well. Incidentally, in the device of this example, when an 8-bit CPU 30 of the position control unit 28 is adopted, the scan time is set to about 105 seconds or less, and the positioning pin 10
The maximum positioning error can be suppressed to about ±0.5 mm or less with a sufficient margin.

Furthermore, as is clear from the above description, in the device of this example, each positioning pin can be adjusted by simply setting or changing the setting data of each storage area m, C of the RAM 32 in the position control unit 28 using the teaching box 42. The target rotational position of lO, the output range of the cam signal, or the number of output ranges can be set or changed. Therefore, even those who do not have specialized knowledge about programs can easily set or change settings, and it is also possible to use a common program even if the settings are different. hand,
It becomes possible to omit the effort of creating separate programs.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited thereto, and various modifications may be made based on the knowledge of those skilled in the art without departing from the spirit thereof. It can be carried out in

For example, in the previous example, the cam signal is output to the PC 26,
Although the cam signal has been used to regulate or control the operation of external devices such as work machines and industrial robots, it is also possible to use the cam signal to control the extension and retraction of the positioning pin 10.

In addition, in the previous example, the protruding and retracting states of the cylinder 12 (positioning pin 10) were set in the input setting state storage area si, but in this input setting state storage area si, work machines, industrial robots, etc. It is also possible to set predetermined operating states of the controller and use those operating states as input conditions. Note that it is not necessary to provide such an input setting state storage area si.

Furthermore, in the previous example, an example was described in which the present invention was applied to a sequence control device for an automobile production line.
Of course, the present invention can also be applied to sequence control devices having a multi-axis positioning function using other PCs.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing an automobile production line equipped with a sequence control device according to the present invention, and FIG. 2 is a plan view for explaining a positioning/fixing pin movement mechanism of the control device. FIG. 3 is a block diagram showing the control system of the control device, and FIG. 4 is a memory map for explaining the setting state of the storage area for position control data in the position control unit of the H1# device. Similarly, FIG. 5 is a memory map for explaining the setting state of the storage area for storing the output range of the cam signal, and FIG. 6 is a memory map for explaining the specific control operation of the position control unit in the control device. It is a flowchart for explaining. lO: Positioning pins 16X, 16Y: i Conductive motor 26: Programmable controller 28: Position control unit 32: RAM 40: Inverter device patent applicant Miyu Kogyo Co., Ltd. agent Patent attorney Yoshi 1) Kazuo

Claims (1)

[Scope of Claims] A sequence control device that uses a programmable controller to sequentially control the positioning work of rotationally moving a plurality of induction motors driven via an inverter device to predetermined target rotational positions, along with other work. (a) having a plurality of target rotational position storage area groups each consisting of a plurality of storage areas each capable of storing target rotational positions of the plurality of induction motors, and a plurality of rotation ranges for each of the plurality of induction motors; (b) selecting from the storage means a group of target rotational position storage areas according to the content of the control operation start signal from the programmable controller; Rotation command signal output for outputting rotation command signals to inverter devices corresponding to the induction motors so as to rotate the induction motors respectively corresponding to the target rotation positions stored in each storage area of the target rotation position storage area group. and (c) a rotation unit that compares the plurality of rotation ranges stored in each of the rotation range storage areas and the actual rotation position of each corresponding induction motor, and outputs a signal according to the comparison result. 1. A sequence control device having a multi-axis positioning function, characterized in that a multi-axis position control unit including a range determining means is provided.