JP3004331B2 - Production line failure analysis method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for controlling a sequence of operations of a facility in a production line. The present invention relates to a method for analyzing a failure of a production line for identifying an operating element that has caused a failure.

2. Description of the Related Art In a production line such as an automobile assembly line, a sequence control unit having a built-in computer is provided for various installed facilities, and the sequence control unit performs operations to be sequentially performed by each facility. It is known to perform the following sequence control. When such sequence control is performed, a sequence control program is loaded into a computer built in the sequence control unit, and the sequence control unit executes each step of operation control for each of various facilities installed on the production line. , According to the sequence control program.

When performing sequence control on the operation of various facilities installed in such a production line, a failure diagnosis for monitoring the control state and detecting a failure in each facility is performed in parallel with the sequence control. Often it is. The fault diagnosis related to the sequence control may take various forms. For example, Japanese Patent Application Laid-Open No. 60-238906 discloses a sequence control under a condition in which equipment can be operated normally. The operation mode of the components of the circuit unit is set in advance as the reference operation mode, and the operation modes of the components of the sequence control circuit unit during the actual operation of the equipment are sequentially compared with the reference operation mode. Performing failure detection based on the failure has been proposed as one of the failure diagnoses related to sequence control.

In addition, a plurality of operation steps are sequentially executed in accordance with a sequence control ladder program loaded on a computer of a sequence control unit, based on a plurality of operations to be performed, which are divided into a plurality of operation steps each representing a predetermined operation unit. When the output operation element to be operated by one of the plurality of operation steps is determined not to operate for the equipment in the production line, the plurality of operation steps in the sequence control section are automatically and sequentially performed. Based on the operation result of the step counter for proceeding to the next step, the operation step in which the output operation element is determined not to operate is identified, the operation element group related to the identified operation step is analyzed, and the cause of the failure is analyzed. There has been proposed a failure diagnosis for identifying the operating element which has become the following.

(Problems to be Solved by the Invention) As described above, the reference operation modes of the components of the sequence control circuit unit are set in advance, and the operation modes of the components of the sequence control circuit unit during the actual operation of the equipment. And the reference operation mode is performed, and when the abnormality of the equipment is to be detected based on the comparison result,
Since the number of the operation modes to be set as the reference operation modes is limited, the operation modes of the actual components of the sequence control circuit unit may be changed despite the fact that the facilities actually operate normally. If the equipment does not match the preset reference operation mode, erroneous detection that the equipment is abnormal may be performed, and when the equipment failure is detected, the failure may be detected. In specifying the operating element in the equipment that caused the failure, the operation modes of the components of the sequence control circuit unit that did not match the reference operation mode and a large number of facilities in the equipment related to the operation mode It is necessary to sequentially check the operating elements in correspondence with each other, and it is often difficult to identify a malfunctioning operating element in a short time.

In addition, in a production line in which various operations to be performed are divided into a plurality of operation steps each representing a predetermined operation unit, the plurality of operation steps are sequentially executed by a sequence control unit according to a sequence control ladder program. For equipment, when a situation occurs in which the output operation element does not operate due to a failure, based on the operation result of the step counter in the sequence control unit,
In the case where a failure diagnosis is performed in which the operation step in which the output operation element is determined not to operate is specified, there is no problem under the condition that a plurality of operation steps are automatically executed sequentially. When the manual operation is performed to activate the selected specific output operation element, the step output in the sequence control unit is not set to the operating state, so that the specific output is performed despite the manual operation. When a failure in which the operating element does not operate occurs, an inconvenience arises in that it is not possible to specify an operating step related to the operating element causing the failure.

In view of such a point, the present invention allows a plurality of operation steps to be sequentially performed in accordance with a sequence control ladder program by a sequence control unit based on a plurality of operation steps each of which represents a predetermined operation unit. When it is determined that the output operation element does not operate due to a failure with respect to the equipment on the production line, the output determined to be inactive based on the operation result of the step counter in the sequence control unit. In a situation where a failure diagnosis is performed in which an operation step relating to an operation element is specified, a specific output operation element is specified even though a manual operation has been performed to operate the selected specific output operation element. When a failure occurs that does not operate, the operation steps related to the operating element that caused the failure. In it will be able to identify the actuating element has a failure cause, and to provide a method of analyzing the failure of the production line.

(Means and Actions for Solving the Problems) In order to achieve the above-described object, in the production line failure analysis method according to the present invention, various operations to be performed by facilities in the production line each represent a predetermined operation unit. For equipment that is to be controlled to sequentially execute a plurality of operation steps in accordance with a sequence control ladder program under a plurality of operation steps, each output operation to be operated in one of the plurality of operation steps Prepare a data map showing the correspondence between a plurality of manual operation means operated to operate the elements by manual operation and a plurality of step ladder operation element groups respectively corresponding to a plurality of operation steps in the sequence control ladder program. Of the equipment, despite the selected one of the manual When the output operation element to be operated does not operate due to a failure, the operated manual operation means is compared with the data map, and the step ladder operation element group corresponding to the operated manual operation means is specified. The group of step ladder operation elements is analyzed to identify non-operational operation elements included therein, and to detect a failure-causing operation element in equipment corresponding to the specified non-operational operation element.

By doing so, the specific output operation element does not operate even though the manual operation has been performed to activate the selected specific output operation element in the equipment for which the sequence control is to be performed. When a failure occurs, the operating element that caused the failure can be quickly and properly identified.

(Embodiment) Prior to description of a production line failure analysis method according to the present invention, FIGS. 2 and 3 show an example of a vehicle assembly line to which the production line failure analysis method according to the present invention is applied. Reference is made here.

In the vehicle assembly line shown in FIGS. 2 and 3, a positioning station ST1 that receives a vehicle body 11 on a receiving base 12, controls the position of the receiving base 12, and positions the body 11 thereon. And a docking station ST2 for combining the engine 14, the front suspension assembly (not shown), the rear suspension assembly 15 and the body 11 mounted on a predetermined position on the pallet 13.
And the engine 1 combined with it against the body 11
4, a fastening station ST3 for fastening and fastening the front suspension assembly and the rear suspension assembly 15 using screws. And, between the positioning station ST1 and the docking station ST2, an overhead transfer device 16 for holding and transporting the body 11 is provided.
Is provided, and the docking station ST2
A pallet transport device 17 for transporting the pallet 13 is provided between the pallet 13 and the fastening station ST3.

The pedestal 12 at the positioning station ST1
It is supposed to travel back and forth along 8,
The positioning station ST1 is provided in relation to the pedestal 12 and moves the pedestal 12 in a direction perpendicular to the rail 18 (vehicle width direction) and in a direction along the rail 18 (front-back direction). A positioning device 19 for positioning the mounted body 11 is provided.

The transfer device 16 includes a guide rail 20, which is disposed over and above the positioning station ST1 and the docking station ST2, and a carrier 21A that moves along the guide rail 20, and a carrier 21A.
Consists of a lifting hanger frame 21B attached to the
As shown in FIG. 4, a left front support arm 22FL and a right front support arm 22FR are attached to the lifting hanger frame 21B via a pair of front arm clamps 22A, respectively. Rear support arms 22RR (not shown) are mounted via a pair of rear arm clamps 22B, respectively. Each of the left front support arm 22FL and the right front support arm 22FR can rotate about the front arm clamp portion 22A as a center of rotation, and guides when the clamp by the front arm clamp portion 22A is released. Take the position that extends along the rail 20, and
In this case, as shown in FIG. 4, a position extending in a direction perpendicular to the guide rail 20 is assumed. Similarly, each of the left rear support arm 22RL and the right rear support arm 22RR also
It is assumed to be able to rotate about B as a rotation center, and takes a position extending along the guide rail 20 when the clamp by the rear arm clamp portion 22B is released,
When the rear arm clamp portion 22B performs the clamping, the rear arm clamp portion 22B assumes a position extending in a direction orthogonal to the guide rail 20.

When the body 11 is transferred to the transfer device 16, the transfer device 16 is moved to a position (original position) above the front end of the rail 18 at the positioning station ST1 as shown by a dashed line in FIG. , The left front support arm 22FL and the right front support arm 22FR are each a front arm clamp unit.
The clamp by 22A is released and extends along the guide rail 20, and each of the left rear support arm 22RL and the right rear support arm 22RR is
The clamp by B is released and arranged so as to extend along the guide rail 20, and then the lifting hanger frame 21B is lowered. Under such circumstances, the cradle 12 on which the body 11 is placed is moved along the rail 18 to the front end thereof, and corresponds to the lifting hanger frame 21B of the transfer device 16 being lowered. Position. Then, the left front support arm 22
Each of the FL and the right front support arm 22FR is rotated and takes a position extending below the front part of the body 11 in a direction perpendicular to the guide rail 20, and the front arm clamp part 22
A, and the left rear support arm 22RL and the right rear support arm 22RR are rotated to extend below the rear part of the body 11 in the direction perpendicular to the guide rail 20. Thus, the rear arm clamp portion 22B is in a state of being clamped. Thereafter, the lifting hanger frame 21B is raised, and as shown in FIG. 4, the body 11 is connected to the left front support arm 22FL and the right front support arm 22FR attached to the lifting hanger frame 21B of the transfer device 16. It is supported by the left rear support arm 22RL and the right rear support arm 22RR.

Further, the pallet transport device 17 includes a pair of guide portions 24L and 24R provided with a large number of support rollers 23 each receiving the lower surface of the pallet 13, and a pair of transport rails 25L extending parallel to the guide portions 24L and 24R, respectively. And 25R, each of which has a pallet locking portion 26 for locking the pallet 13, and each of the transport rails 15L
And pallet carrier 2 that moves along 25R
7L and 27R, and a linear motor mechanism (not shown) for driving the pallet transfer tables 27L and 27R.

When the front suspension assembly and the rear suspension assembly 15 are assembled, the docking station ST2 includes struts in the front suspension assembly and struts in the rear suspension assembly 15.
A pair of left and right front clamp arms 30L and 30R, each of which supports the 15A and takes an assembled posture, and a pair of left and right rear clamp arms 31L and 31R are provided. The left and right front clamp arms 30L and 30R are respectively provided with mounting plate portions 32L and 32R.
Are mounted so that they can move forward and backward in the direction perpendicular to the transport rails 25L and 25R, and the left and right rear clamp arms 31L and 31R are attached to the mounting plate parts 33L and 33R, respectively, in the direction perpendicular to the transport rails 25L and 25R. The left and right front clamp arms 30L and 3
0R mutually opposing tip and right and left rear clamp arm 31
Each of the mutually opposing distal ends of L and 31R has an engaging portion that engages with a strut in the front suspension assembly or a strut 15A in the rear suspension assembly 15. The mounting plate 32L is moved by the arm slide 34L to the fixed base 35L with respect to the transfer rail.
It is movable in the direction along 25L and 25R, and the mounting plate part 32R
Is movable with respect to the fixed base 35R by the arm slide 34R in the direction along the transfer rails 25L and 25R, and the mounting plate portion 33L is fixed to the fixed base 37L by the arm slide 36L and the transfer rails 25L and 25R. The mounting plate 33R can be moved by the arm slide 36R in the direction along the transfer rails 25L and 25R with respect to the fixed base 37R. Therefore, the left and right front clamp arms 30L and 30R can be moved back and forth and left and right under the state where their distal ends are engaged with struts in the front suspension assembly,
The left and right rear clamp arms 31L and 31R can be moved back and forth and left and right under a state in which their distal ends are engaged with struts 15A in the rear suspension assembly 15, and the left and right front clamp arms 30L and 30R. , Arm slides 34L and 34R, left and right rear clamp arms 31L and 31
The R and the arm slides 36L and 36R constitute a docking device 40.

Further, in the docking station ST2, a pair of slide rails 41L and 41R and a slide rail 41L which are installed so as to extend in parallel with the transfer rails 25L and 25R, respectively.
And movable member 42, which is supposed to slide along 41R,
A slide device including a motor 43 for driving a movable member 42 and the like
A movable member 42 of the slide device 45 is provided with an engagement means 46 which engages with a movable engine support member (not shown) provided on the pallet 13.
Is provided. Further, two lifting pallet reference pins for positioning the pallet 13 at a predetermined position.
47 are also provided. The slide device 45 is mounted on the body 11 supported by the left front support arm 22FL and the right front support arm 22FR and the left rear support arm 22RL and the right rear support arm 22RR attached to the lifting hanger frame 21B in the transfer device 16, Engines 14 on pallets 13
When the front suspension assembly and the rear suspension assembly 15 are combined, the engaging means 46 is moved back and forth while engaging with the movable engine support member on the pallet 13 positioned by the lifting pallet reference pin 47,
Thereby, the engine 14 is moved back and forth with respect to the body 11, so that interference between the body 11 and the engine 14 is avoided.

In the fastening station ST3, a robot 48A that is to perform screw fastening work for fastening the engine 14 and the front suspension assembly combined with the body 11 to the body 11, and a rear suspension assembly 15 combined with the body 11 A robot 48B, which is to perform a screw tightening operation for fastening, is installed. Further, also at the fastening station ST3, two lifting / lowering pallet reference pins, which are to position the pallet 13 at a predetermined position. 47 are provided.

In the vehicle assembly line as described above, the positioning device 19 in the positioning station ST1, the transfer device 16, the docking device 40 and the slide device 45 in the docking station ST2, the pallet transport device 17, and the robots 48A and 48B in the fastening station ST3. The sequence control unit connected thereto is a facility (sequence control target facility) that performs sequence control on those operations based on a sequence control program.

The operations performed by each of these sequence control target facilities are divided into operation blocks defined as the maximum unit of a series of operations that can be performed independently from the start to the end, and B0 to B0 are as follows. It is assumed that 12 operation blocks of B11 are obtained.

B0: Operation block (positioning block positioning operation block) for positioning the receiving table 12 and the body 11 thereon by the positioning device 19.

B1: Operation block for preparing for transfer of the body 11 by the transfer device 16 (transfer device preparation operation block).

B2: The strut of the front suspension assembly is clamped by the left and right front clamp arms 30L and 30R by the docking device 40, and the left and right rear clamp arms 31 are provided.
Struts for rear suspension assembly 15 with L and 31R
Operation block for preparing to clamp 15A (Strut clamp preparation operation block).

B3: Cradle 12 positioned by positioning device 19
The upper body 11 is transferred to the lifting hanger frame 21B in the transfer device 16, and the lifting hanger frame 21B is moved.
An operation block (transfer device receiving operation block) that is supported and conveyed by the left front support arm 22FL and the right front support arm 22FR and the left rear support arm 22RL and the right rear support arm 22RR attached to the control unit.

B4: Operation block (slide device preparation operation block) for preparing the engagement of the engagement means 46 provided on the movable member 42 with the movable engine support member on the pallet 13 by the slide device 45.

B5: An operation block for returning the cradle 12 to the original position by the positioning device 19 (a cradle original position return operation block).

B6: Left front support arm 22FL, right front support arm 22FR, left rear support arm 22RL, and right rear support arm 22 attached to lifting hanger frame 21B in transfer device 16
The engine 11 arranged on the pallet 13 and the body 11 supported by the RR and the pallet 13
Operation block (engine / suspension docking operation block) combining a front suspension assembly strut clamped by the left and right front clamp arms 30L and 30R and a strut 15A of a rear suspension assembly 15 clamped by the left and right rear clamp arms 31L and 31R. ).

B7: Operation block where the transfer device 16 returns to the original position (transfer device original position return operation block).

B8: Left and right front clamp arms 30L and 30R, and left and right rear clamp arms 31L and 3 by docking device 40
Operation block for returning each 1R to the original position (clamp arm original position return operation block).

B9: An operation block for operating the linear motor by the pallet transfer device 17 to transfer the pallet 13 on which the body 11 in which the engine 14, the front suspension assembly, and the rear suspension assembly 15 are combined to the fastening station ST3 ( Linear motor propulsion block).

B10: An operation block (screw fastening operation block) for performing a screw fastening operation for fastening the engine 14 and the front suspension combined with the body 11 to the body 11 by the robot 48A.

B11: An operation block (screw fastening operation block) for performing a screw fastening operation for fastening the rear suspension assembly 15 combined with the body 11 to the body 11 by the robot 48B.

The positioning device 19, the transfer device 16, the docking device 40, the slide device 45, the pallet transport device 17, and the robots 48A and 48, which are divided into such operation blocks B0 to B11.
The operation performed by each of the units B proceeds in accordance with an operation block flowchart as shown in FIG. In addition,
In the operation block flowchart of FIG. 5, A0 to A4
Represents the initial settings.

Each of the above-described operation blocks B0 to B11 is divided into a plurality of operation steps, each of which includes an output operation.For example, for the transfer device receiving operation block B3, six operation blocks B3S0 to B3S5 are provided as follows. It is divided into operation steps.

B3S0: An operation step in which the left front support arm 22FL of the transfer device 16 rotates and takes a position extending in a direction perpendicular to the guide rail 20 (left front support arm rotation operation step).

B3S1: An operation step in which the right front support arm 22FR of the transfer device 16 rotates and takes a position extending in a direction orthogonal to the guide rail 20 (right front support arm rotation operation step).

B3S2: Operation step in which the left rear support arm 22RL of the transfer device 16 rotates and takes a position extending in a direction orthogonal to the guide rail 20 (left rear support arm rotation operation step).

B3S3: An operation step in which the right rear support arm 22RR of the transfer device 16 rotates and takes a position extending in a direction perpendicular to the guide rail 20 (right rear support arm rotation operation step).

B3S4: The front arm clamp portion 22A and the rear arm clamp portion 22B in the transfer device 16 are respectively formed by both the left front support arm 22FL and the right front support arm 22FR, and the left rear support arm 22RL and the right rear support arm 22RR. Operation step for clamping both (arm clamp operation step).

B3S5: Operation step in which the elevating hanger frame 21B in the transfer device 16 is elevated (elevating hanger frame elevating operation step).

Subsequently, the positioning device in the above-described vehicle assembly line
19, a transfer device 16, a docking device 40, a slide device 45, a pallet transfer device 17, and a production device according to the present invention, which is applied to a vehicle assembly line in which equipment to be sequenced such as robots 48A and 48B is installed. An example of a line failure analysis method will be described.

FIG. 6 shows a failure diagnosis system in which an example of a production line failure analysis method according to the present invention is implemented, together with sequence control target facilities and a sequence control unit connected thereto. As described above, the sequence control target equipment 50 includes the positioning device 19, the transfer device 16, the docking device 40, the slide device 45, the pallet transport device 17, and the robots 48A and 48.
B, and is to be subjected to sequence control by the sequence control unit 51.

Equipment 50 subject to sequence control by sequence controller 51
The sequence control for the operation of
The sequence control program is performed based on a sequence control program loaded into a computer built in the computer 51. Such a sequence control program is, for example, as shown in FIG. 7 for one operation step in a certain operation block. Is a sequence control ladder program configured to correspond to this ladder program. The ladder program shown in FIG. 7 is composed of a step ladder operation element group G _ns and a step ladder operation element group G _no . In the step ladder operation element group G _ns , (M _n ) is an intermediate output. Yn _-1 is an operation element for confirming the operation of the output operation element relating to the preceding operation step, and ILC-1 and ILC-2 are interfaces for setting the operation conditions of the intermediate output operation element ( _Mn ). A lock, _Xn represents a manual operation element, ILC-m represents an interlock associated with the manual operation element _Xn , and a step ladder operation element group G
_{In no} , (Y _n ) represents an output operation element, and M _n represents an operation element corresponding to the intermediate output operation element (M _n ).

The failure diagnosis system includes a failure diagnosis controller 52. The failure diagnosis controller 52 includes a central processing unit (CPU) 62, a memory 63, and an input / output interface (I / O interface) connected through a bus line 61. / O interface) 64, a transmission / reception interface 65, and a hard disk device 66 as an auxiliary memory connected to the I / O interface 64, a cathode ray tube (CRT) 67 for display, and for inputting data and control codes. Keyboard 68 is provided. The transmission / reception interface 65 and the transmission / reception interface 51A provided in the sequence control unit 51 are interconnected.

The failure diagnosis controller 52 receives a transmission / reception interface from the sequence controller 51 in accordance with the operation of the keyboard 68.
Through 51A and 65, program processing data including data representing the contents of a register into which the output of a step counter representing the progress status of sequence control for the sequence control target equipment 50 is received, and the CPU 62 writes data in the memory 63 and Under the reading, the occurrence of a failure in the sequence control target equipment 50 is detected based on the program processing data from the sequence control unit 51, and when the occurrence of the failure is detected, the display CRT 67 is used. The display regarding the failure is made in. In the hard disk device 66, data representing each step ladder element in the sequence control ladder program loaded on the computer built in the sequence control unit 51 is stored in a state of being individually read out. Is supposed to build a database.

Then, under the condition that the sequence control is performed on the sequence control target equipment 50 according to the sequence control ladder program loaded on the computer built in the sequence control unit 51, the CPU 62 in the failure diagnosis control device 52 includes: The program processing data is received in order from the sequence control unit 51 via the transmission / reception interfaces 51A and 65, and the failure in the sequence control target equipment 50 based on the program processing data from the sequence control unit 51 is performed according to the failure diagnosis program loaded in the CPU 62. Detection of the occurrence of a failure and investigation of a failure-causing operation element when the occurrence of a failure is detected. Equipment subject to sequence control in a state where such sequence control is performed
The detection of the occurrence of the failure in 50 and the investigation of the failure cause operation element when the occurrence of the failure is detected are performed through each of the execution blocks B0 to B11 sequentially executed according to the operation block flowchart shown in FIG. The failure diagnosis is performed individually.

For example, first, the detection of the occurrence of a failure through each of the operation blocks B0 to B11 is performed by measuring the execution time from the start time to the end time of a plurality of operation steps constituting the operation block, and measuring the actual execution time. The time is compared with a preset reference time, and when the actual execution time measured is longer than the reference time, the positioning device 19 in the sequence control target equipment 50 that has executed the operation block,
This is performed by determining that a failure has occurred in any of the transfer device 16, the docking device 40, the slide device 45, the pallet transport device 17, and the robots 48A and 48B. Then, when the occurrence of a failure is detected through each of the operation blocks B0 to B11, the operation step related to the output operation element that has been disabled due to the failure in the operation block is a sequence from the sequence control unit 51. Indicating the progress status of the sequence control for the control target equipment 50, the output of the step counter is specified based on the program processing data including the data representing the contents of the register to be taken in, and further, in the equipment that has performed the specified operation step By identifying the operating element that causes the output operating element to assume the non-operating state, the malfunctioning operating element is determined.

Under such circumstances, the sequence control target equipment 50 is not brought into a state in which sequence control is performed according to the sequence control ladder program loaded on the computer built in the sequence control unit 51, and the output operation related to each operation step is not performed. In the case where the operation state of the element is obtained in response to the manual operation, an example of the production line failure analysis method according to the present invention is performed, but prior to that, a plurality of operation steps for each operation block are performed. A step data map including data relating to the correspondence between the output operation element, the intermediate output operation element, and the manual operation element relating to each of the above is prepared, and is stored in the hard disk device 66 in advance. Such a step data map is represented by, for example, Table 1 below for the above-described transfer device receiving operation block B3.
It looks like a B3 data map.

The manual operation for causing the sequence control target facility 50 to selectively take the state in which the output operation element relating to each operation step is to be operated is, for example, a manual operation element X _n in the ladder program shown in FIG. For example, an output operation which is performed by operating a manual operation switch and which is set to be in an operation state despite the manual operation switch being operated. When a failure occurs in which an element is not brought into an operation state, an example of a production line failure analysis method according to the present invention is performed. In the following, a failure diagnosis control device
The operation performed by the CPU 62 in 52 to specify the failure-causing operation element that caused the failure in which the output operation element to be brought into the operation state is not brought into the operation state will be described with reference to the flowchart shown in FIG.

If a failure occurs in which the output operation element to be activated is not activated even though the manual operation switch is operated, for example, a specific key of the keyboard 68 in the failure diagnosis control device 52, or The analysis request means provided in the failure diagnosis control device 52 is operated together with the manual operation switch, and the analysis request signal is input to the CPU 62.

CPU62 waits for the analysis request signal is input, if the analysis request signal is input, the time, for example, a manually operated element X _n at step ladder actuating element group G _ns shown in Figure 7 It is determined whether the manual operation switch corresponding to such a manual operation element is operated and turned on, and if the manual operation switch is not operated and turned on, the analysis request signal is input again. The process returns to the state of waiting for the completion (steps S1 and S2). On the other hand, the manual operation when the switch is operated by being turned on, the manual operation switch is operated corresponds, as the manual operating elements X _n at step ladder actuating element group G _ns shown in Figure 7 Check the manually operated element X _x (Step
S3).

Then, CPU 62 has a confirmed manually operated element X _x, read from the hard disk 66, against the step data map as the B3 data map shown in Table 1, a manual operation which is set in the step data map From the correspondence between the element and the intermediate output operation element, for example, if the manual operation element X _x is the manual operation element X5, the intermediate output operation element M5
As an intermediate power actuating element (M _x )
An intermediate output operation element (M _n ) in the step ladder operation element group C _ns shown in FIG. 7 corresponding to the manual operation element X _x
An intermediate output operation element (M _x ) is specified (step S4). Such an intermediate output operation element (M _x ) is assumed to be in a non-operation state. Then, a step ladder operation element group G such as the step ladder operation element group G _ns shown in FIG. 7 involving the specified intermediate output operation element (M _x ).
_xs is specified (step S5). Such a step ladder operation element group G _xs includes an operation element corresponding to the intermediate output operation element (M _x ) and an output operation element that should have been brought into an operation state by operating a manual operation switch. in a step ladder actuating element group G _xo of as a step ladder actuating element group G _no shown in FIG. 7, it is to form a ladder program corresponding to one of the operation steps.

Then, CPU 62 is in the step ladder actuating element group G _xs identified, analyzed interlocks corresponding to interlock ILC-2 and interlock ILC-m in the step ladder actuating element group G _ns shown in Figure 7 (Step S6) to identify the non-operational actuation element that is causing the intermediate output activation element (M _x ) to assume the non-operational state;
Based on the specified non-operational operation element, a failure-causing operation element in the sequence control target equipment 50 is detected (step S7).

In this way, in the event that a failure occurs in which the output operation element to be activated is not activated even though the activation operation switch is operated, the step data map prepared in advance is used, The step ladder operation element group related to the manually operated element corresponding to the operated manual operation switch to be analyzed for the search for the non-operation operation element is identified, so that the equipment to be sequence-controlled is identified. The detection of the cause-of-fault operating element at 50 will be performed quickly.

(Effects of the Invention) As is apparent from the above description, according to the production line failure analysis method of the present invention, various operations to be performed are divided into a plurality of operation steps each representing a predetermined operation unit. In the case of equipment on a production line in which a plurality of operation steps are sequentially executed by a sequence control unit in accordance with a sequence control program, when a failure occurs and an output operation element is not operated, the output from the sequence control unit is obtained. In a situation in which a failure diagnosis is performed in which an operation step involving an output operation element determined to be inoperable is specified based on data representing a progress state of the sequence control of the equipment to be performed, the equipment is subjected to sequence control. The sequence control according to the ladder program is not performed. If the operating state of the relevant output actuating element is to be obtained in response to a manual operation, the specific output actuating element may not be operated even though the manual operation has been performed to activate the selected specific output actuating element. When an inoperative fault occurs, the operating steps involving the manually operated element corresponding to the operated manual operating means are quickly and accurately specified, so that the faulty operating element in the equipment can be quickly detected.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining the investigation of a failure-causing operating element performed in accordance with an example of a failure analysis method for a production line according to the present invention. FIGS. 2, 3, and 4 are production flowcharts according to the present invention. FIG. 5 is a schematic configuration diagram showing an example of a vehicle assembly line to which the line failure analysis method is applied, FIG. 5 is an operation block flowchart for explaining sequence control for equipment to be sequence-controlled, and FIG. 6 is production according to the present invention. FIG. 7 is a configuration diagram showing a failure diagnosis system in which an example of a line failure analysis method is implemented, together with a sequence control target facility and a sequence control unit. FIG. 7 shows sequence control used for sequence control of the sequence control target facility by the sequence control unit. FIG. 4 is a ladder diagram showing a part of an example of a program. In the figure, 16 is a transfer device, 17 is a pallet transport device, 19 is a positioning device, 40 is a docking device, 45 is a slide device, 48
A and 48B are robots, 50 is equipment subject to sequence control, 51
Is a sequence control unit, 52 is a failure diagnosis control device, 61 is a bus line, 62 is a central processing unit (CPU), 63 is a memory, 6
4 is an input / output interface (I / O interface),
66 is a hard disk drive, 67 is a cathode ray tube (CRT) for display, and 68 is a keyboard.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23Q 41/00-41/08 G06F 15/29

Claims (2)

(57) [Claims] 1. A method for controlling a plurality of operation steps to be performed by a facility on a production line so as to sequentially execute the plurality of operation steps in accordance with a sequence control ladder program based on a plurality of operation steps each representing a predetermined operation unit. A plurality of manual operation means, each of which is operated to manually operate an output operation element to be operated in one of the plurality of operation steps, and the sequence control ladder program. Prepare a data map representing the corresponding relationship with a plurality of step ladder operation element groups corresponding to the plurality of operation steps respectively, even though a selected one of the plurality of manual operation means was operated, When the output operation element to be operated does not operate due to the failure of the above equipment Compares the operated manual operation means with the data map, specifies a step ladder operation element group corresponding to the operated manual operation means, analyzes the specified step ladder operation element group, and A failure analysis method for a production line, comprising: identifying a non-operation element included in a ladder operation element group and detecting a failure-causing operation element in the equipment corresponding to the identified non-operation element. 2. The production line according to claim 1, wherein the data map includes data relating to the correspondence between the output operation element, the intermediate operation element and the manual operation element relating to each of the plurality of operation steps. Failure analysis method.