JP5730818B2 - Work position discrimination system and work position discrimination method - Google Patents

Description

  The present invention relates to a work position discriminating system and a work position discriminating method for discriminating whether or not a work position is correct at a practical site such as a manufacturing factory.

  In recent years, production engineering departments of manufacturers of electrical products and automobiles have mainly aimed at improving productivity, detecting work mistakes such as forgetting to tighten bolts during assembly work, and in real time the state of assembly work In order to omit the inspection process and inspection time after the operation by detecting and feeding back, optical or magnetic position measurement is performed.

  In optical position measurement, the reflected light that is reflected by irradiating light from the light source to the measurement object is received by the optical sensor to obtain position information. Therefore, the blind spot created by the operator hinders measurement. is there. On the other hand, in magnetic position measurement, position information is obtained using a transmitter that generates a magnetic field and a magnetic sensor, so that it does not interfere with measurement, but there is metal around the assembly work. Then, since the magnetic field is distorted, there is a difficulty that the position coordinates at the measurement position are displaced. Therefore, the current situation is that the use in an environment such as a manufacturing factory where many metals exist is avoided as much as possible.

  In order to eliminate such difficulties in magnetic position measurement, an error in the magnetic position measurement system that can easily and quickly create a look-up table that corrects position coordinate measurement errors caused by magnetic field distortion. A calibration method has been proposed (see, for example, Patent Document 1).

  This magnetic position measuring system includes a measuring rod in which a plurality of magnetic sensors are linearly arranged at equal intervals on a rod made of a non-magnetic member, and a transmitter that generates a magnetic field that can be sensed by the magnetic sensor. The error calibration method of this magnetic position measurement system is obtained by calculating in advance the position coordinates obtained from the actual measurement values of the magnetic sensor attached to the measurement rod by arbitrarily moving the measurement rod within the measurement range. Comparing the difference with the exact position coordinates of the magnetic sensor to determine the magnitude of the error and the reliability of the error, and when the error reliability is high, the look-up table is updated under certain conditions It is.

JP 2004-101273 A

  However, in the error calibration method of the magnetic position measurement system described in the background art, a lookup table using a measurement bar in which a plurality of magnetic sensors are linearly arranged at equal intervals on a bar made of a non-magnetic member. The purpose of this is to correct the position coordinate error that increases in the distance by performing the linear interpolation, so the magnetic field is locally distorted nonlinearly due to the influence of the metal body of the tool box, parts storage shelf, etc. In the assembly work place, it has not been possible to accurately determine whether or not the work position is the correct position.

  In addition, the error correction method of this magnetic position measurement system performs linear interpolation using a look-up table on the assumption that the magnetic field in the space near the transmitter is not distorted. In the case where the distortion has occurred, it has not been possible to accurately determine whether or not the work position is the correct position.

  Also, with this error correction method of the magnetic position measurement system, there are many obstacles such as tool boxes and parts storage shelves at work sites such as manufacturing factories, so it is difficult to swing the measuring rod. there were.

  Therefore, a worker Wo uses an automatic screw tightening machine (nut runner) 1 to screw a part such as a brake hose in a lower part of the chassis Ch as shown in FIG. In such an operation, a plurality of metal bodies MB such as a tool table and a component storage box are arranged in the vicinity, so that such an error calibration method of the magnetic position measurement system cannot be applied.

  The present invention has been made to solve such a conventional difficulty, and even if a metal body is arranged in the vicinity of the position where the work is actually performed, the position coordinate measurement error caused by the distortion of the magnetic field is reduced. It is an object of the present invention to provide a work position determination system and a work position determination method capable of accurately determining whether or not the position where the work is performed with high accuracy without correction.

  The work position determination system according to the first aspect of the present invention that achieves the above-described object includes at least two magnetic sensors disposed on the work implement at different distances from a predetermined work site of the work implement, Each of the magnetic sensors can move on a virtual spherical surface having a radius between the swing center and the magnetic sensor when the magnetic sensor swings around the work site. The three-dimensional coordinate data and the swing of the three-dimensional coordinate data group on the virtual spherical surface of each of the magnetic sensors when the workpiece is swung around the swing portion within the predetermined normal working range in FIG. When the reference data in which the center is associated with a straight line is a database for each different work, and a predetermined work is started with the work implement Reference data corresponding to a predetermined work is selected from the reference database, each 3D coordinate data output from each magnetic sensor, and each 3D coordinate data group of each magnetic sensor included in the reference data. When data matching is performed as a result of data matching using the data matching function that performs data matching with the dimensional coordinate data and the data matching function, the work position of the work part of the work implement is assumed to be a normal work position. It is comprised from the work analysis part which has the work position determination function to determine.

  According to a second aspect of the present invention, in the work position determination system according to the first aspect, when the work position determination function of the work analysis unit determines that the work position of the work part of the work implement is not a normal work position. Is provided with a notification unit that notifies a warning.

  According to a third aspect of the present invention, in the work position determination system according to the first aspect or the second aspect, the work analysis unit generates the reference database corresponding to the predetermined work performed by the work implement. Within a predetermined normal working range on each virtual sphere of each magnetic sensor corresponding to the work, the work tool is swung so that the worker for creating the reference data draws a predetermined trajectory. When the center is swung, a data collection function that collects data for collecting a plurality of three-dimensional coordinates measured on a predetermined locus for each magnetic sensor, and each point collected by the data collection function for each magnetic sensor 3D coordinates missing within a predetermined normal working range on the virtual sphere by performing cubic interpolation on the 3D coordinate collection data A reference data creation function that creates a reference data by associating each 3D coordinate data of the 3D coordinate data group on the virtual sphere on which the calculated sphere is associated with a swing center in a straight line, and a reference data creation function, It has a reference database creation function for creating a database of reference data created for different operations.

  In the work position determination method according to the fourth aspect of the present invention, at least two magnetic sensors are disposed on the work implement at different distances from a predetermined work site of the work implement, and each magnetic sensor Each of the magnetic sensors can move on a virtual spherical surface having a radius between the swing center and the magnetic sensor when the magnetic sensor swings around the work site as a swing center, and is output from each magnetic sensor. The work analysis unit that has received each of the three-dimensional coordinate data is a work position determination method for estimating a normal work position of the work part based on each three-dimensional coordinate data. When the predetermined work is started, the virtual sphere of each magnetic sensor when the work part is swung around the rocking center within a predetermined normal work range on the virtual spherical surface. Reference data in which the three-dimensional coordinate data of the upper three-dimensional coordinate data group and the swing center are associated with each other in a straight line is a reference database corresponding to a predetermined work from a reference database created for each different work. Reference data selection step for selecting data, each three-dimensional coordinate data output from each magnetic sensor of the work implement in a predetermined work, and each of the three-dimensional coordinate data group of each magnetic sensor included in the reference data The data matching step for performing data matching with the three-dimensional coordinate data, and the result of performing the data matching in the data matching step is that when the data matching is performed, the work position of the work part of the work implement is a normal work position. And a work position determination step for determining A.

  In the work position determination method according to the fourth aspect of the present invention, when the work position determination step determines that the work position of the work part of the work implement is not a normal work position in the work position determination method according to the fourth aspect, It has a determination information notifying step for notifying an alarm.

  According to a sixth aspect of the present invention, in the work position determination method according to the fourth aspect or the fifth aspect, the work analysis unit generates the reference database corresponding to the predetermined work performed by the work implement. Within a predetermined normal working range on each virtual sphere of each magnetic sensor corresponding to the work, the work tool is swung so that the worker for creating the reference data draws a predetermined trajectory. When rocking about the center, a data collection step for collecting data for collecting a plurality of three-dimensional coordinates measured on a predetermined locus for each magnetic sensor, and each point collected in the data collection step for each magnetic sensor 3D missing within a predetermined normal working range on the virtual sphere by performing cubic interpolation on the collection data of 3D coordinates A reference data creating step for creating reference data by associating each three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual spherical surface for which the characteristic value has been calculated with the swing center in a straight line; and a reference data creating step And a reference database creation step for creating a database of reference data created for different operations.

  According to a seventh aspect of the present invention, in the work position determination method according to any one of the fourth to sixth aspects, the data matching step is output from each magnetic sensor of the work implement in a predetermined work. Data matching is performed using a difference value between each of the three-dimensional coordinate data and the three-dimensional coordinate data of each three-dimensional coordinate data group of each magnetic sensor included in the reference data.

  According to the work position discriminating apparatus and the work position discriminating method of the present invention as described above, at least two magnetic sensors are located at different distances from the work part, with the predetermined work part of the work implement as the swing center. Because it is placed on the work implement, in work where the work site of the work implement is the center of oscillation, each magnetic sensor moves on a virtual sphere whose radius is the distance between the oscillation center and each magnetic sensor. Therefore, by associating each three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual spherical surface of each magnetic sensor with the swing center in a straight line, the work performed by the operator is If each magnetic sensor is moving within a predetermined normal working range on each virtual spherical surface, each three-dimensional coordinate data output from each magnetic sensor is displayed. And the three-dimensional coordinate data of the three-dimensional coordinate data group of each magnetic sensor included in the reference data are data-matched so that the work position of the work part of the work implement is a normal work position. Become.

  If the data matching is not performed, the operator can confirm that the work is not normal by notifying the alarm indicating that the work position is not the work position of the work tool from the notification unit.

  According to the work position discriminating system and the work position discriminating method of the present invention, at least two magnetic sensors are placed on the work implement at different distances from the work site, with a predetermined work site of the work implement as a swing center. In the work where the work site of the work implement is placed at the swing center, each magnetic sensor moves on a virtual spherical surface whose radius is the distance between the swing center and each magnetic sensor. By associating the three-dimensional coordinate data on the virtual sphere of each magnetic sensor with the origin in a straight line, even if a metal object is placed in the vicinity of the actual work position, the position caused by the distortion of the magnetic field It becomes possible to determine with high accuracy whether or not the position where the operation is performed is correct without correcting the coordinate measurement error.

It is a block diagram of a system configuration showing a preferred embodiment in a work position discrimination system of the present invention. FIG. 5 shows a trajectory of a magnetic sensor when a work implement in which a magnetic sensor as a component of the work position determination system of the present invention is arranged and the work implement is moved to draw a predetermined trajectory in order to create reference data. In the figure, (A) is an explanatory diagram showing the relationship between the work implement and the trajectory of the magnetic sensor, (B) is an explanatory diagram showing only the trajectory of the magnetic sensor, and (C) is an illustration of the trajectory of the magnetic sensor and the three-dimensional coordinate data. It is explanatory drawing which shows the relationship with the area of distribution information. FIG. 3 is an explanatory diagram showing an operation state for drawing a trajectory as shown in FIG. 2 on a work implement provided with a magnetic sensor that is a component of the work position determination system of the present invention. It is a flowchart figure which shows the example of preferable embodiment of the working position discrimination method of this invention. It is a figure which shows the example of preferable embodiment of the working position discrimination method of this invention, and is a flowchart figure for creating a reference database. It is explanatory drawing which shows the operation state which screws components, such as a brake hose, to a lower circumference part of a vehicle using a nut runner.

  Embodiments for carrying out the work position discriminating apparatus and the work position discriminating method of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the work position determination apparatus of the present invention includes two magnetic sensors 2 </ b> A and 2 </ b> B arranged on the work implement 1 at different distances from a predetermined work site 1 a of the work implement 1. Each of the magnetic sensors 2A and 2B can move on an imaginary spherical surface having a radius between the swing center 1a and the magnetic sensor when the magnetic sensor swings around the work site 1a. It can be done. Here, the work part 1a of the work tool 1 refers to a part that comes into contact with an object for performing the work when the work tool 1 is performing a predetermined work.

  A transmitter (not shown) that generates a magnetic field that can be sensed by the two magnetic sensors 2A and 2B is installed in the work area. Further, since the work implement 1 is used within the reach of three orthogonal magnetic fields generated from the transmitter, the two magnetic sensors 2A and 2B obtain three-dimensional coordinate information as position information. 3D coordinate data is output.

  Also, the work position determination device of the present invention outputs the magnetic sensors 2A and 2B from the magnetic sensors 2A and 2B when the magnetic sensors 2A and 2B perform the work such that the work part 1a swings around the work part 1a. When receiving the respective three-dimensional coordinate data, the data processing device 3 having the work analysis unit 31 for estimating the normal work position of the work part 1a based on each three-dimensional coordinate data is provided.

  The data processing device 3 is preferably a computer, and includes an arithmetic processing device such as a CPU, a display device having a display screen such as a cathode ray tube monitor and a liquid crystal display, an input device such as a keyboard and a mouse, a hard disk drive, etc. It is comprised by the memory | storage device.

  In such a data processing device 3, a reference database that is databased for each operation having different reference data is registered in the data storage unit 32. This reference data is the first when the work site 1a of the work implement 1 is swung around the swing center within a predetermined normal work range on the virtual spherical surface of the two magnetic sensors 2A, 2B. The three-dimensional coordinate data on the virtual spherical surface of the magnetic sensor 2A, the three-dimensional coordinate data on the virtual spherical surface of the second magnetic sensor 2B, and the swing center 1a are associated in a straight line. The straight line here means that the two magnetic sensors 2A and 2B are arranged on the straight line from the swing center 1a of the work implement 1. Hereinafter, “the three-dimensional coordinate data of each three-dimensional coordinate data group of each magnetic sensor 2 </ b> A, 2 </ b> B is associated with the swing center 1 a in a straight line” has the same meaning.

  Further, when a predetermined work is started by the work implement 1, the work analysis unit 31 of the data processing device 3 selects reference data corresponding to the predetermined work from the reference database, and is output from each of the magnetic sensors 2A and 2B. A data matching function 31d for performing data matching between each of the three-dimensional coordinate data coming in and each of the three-dimensional coordinate data of each of the three-dimensional coordinate data groups of the magnetic sensors 2A and 2B included in the reference data; When the data matching is performed as a result of the data matching at 31d, the work position determination function 31e for determining that the work position of the work part 1a of the work implement 1 is a normal work position is provided.

  Furthermore, in order to create a reference database corresponding to a predetermined work by the work implement 1 registered in the data storage unit 32, the work analysis unit 31 includes virtual spherical surfaces of the magnetic sensors 2A and 2B corresponding to the predetermined work. When the work implement 1 is swung around the work site 1a as a swing center so that a skilled worker for creating reference data draws a predetermined trajectory within the predetermined normal work range above, A data collection function 31a for collecting data for collecting a plurality of three-dimensional coordinates measured on a predetermined trajectory for each magnetic sensor 2A, 2B, and each data collected by the data collection function 31a for each magnetic sensor 2A, 2B Cubic interpolation is performed on the data for collecting the three-dimensional coordinates of the points so that they are missing within a predetermined normal working range on the virtual sphere. A reference data creation function 31b for creating reference data by linearly associating each three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual sphere on which the three-dimensional coordinate value is calculated with the swing center 1a; The reference data creation function 31b has a reference database creation function 31c that converts the reference data created for each different work into a database.

  The reference data creation function 31b can create a virtual spherical surface in a three-dimensional space by using, for example, cubic (cube interpolation) in griddata (data grid) which is a command of MATLAB (registered trademark). By using meshgrid (two-dimensional and three-dimensional space quadrilateral grids), which is a command of MATLAB, a three-dimensional coordinate data group can be obtained with an arbitrary resolution. In this case, if a metal body is arranged in the vicinity of the position where the work is performed, the magnetic field is locally distorted nonlinearly due to the influence of the metal body, so the distance between the oscillation center 1a and the magnetic sensor is defined as the radius. The phantom sphere is a sphere that is nonlinearly distorted by the distortion of the magnetic field, but since the magnetic field distribution is always stable, the value of the three-dimensional coordinate data group on the phantom sphere is always stable. Therefore, it can be used as reference data.

  Here, a case where a nutrunner is used as the work implement 1 will be described in which the work implement 1 is swung around the work portion 1a as a swing center so that the skilled worker draws a predetermined trajectory. The nut runner 1 is provided with a socket on an output shaft extending from the nut runner main body, and the socket is detachably fitted to a bolt, a nut, or the like, and the bolt, the nut, or the like is tightened. Therefore, since the site | part fitted to the volt | bolt, nut, etc. of a socket becomes the work site | part 1a, below, this site | part of a socket is called the work site | part 1a. In addition, since this work part 1a also becomes a rocking | fluctuation center, the position is a point.

  In order to cause the skilled worker to draw a predetermined trajectory with such a nut runner 1, the nut runner 1 is rotated or tilted as shown in FIG. It can be carried out.

  Therefore, for example, as shown in FIGS. 3A and 3C, the virtual spherical surface of the magnetic sensor 2A corresponding to the predetermined work is VS1, and the virtual spherical surface of the magnetic sensor 2B is VS2, and the magnetic corresponding to the predetermined work. A predetermined normal work range on the virtual spherical surface VS1 of the sensor 2A is Ar1, and a predetermined normal work range on the virtual spherical surface VS2 of the magnetic sensor 2B corresponding to the predetermined work is Ar2. Further, the predetermined trajectory drawn by the skilled worker is, for example, Tr1 in the magnetic sensor 2A and Tr2 in the magnetic sensor 2B in FIGS. 3 (A), (B), and (C). That is, this predetermined locus has a spiral shape and a shape like an umbrella bone.

  In addition, the work position determination device according to the present invention provides a notification unit that issues a warning when the work position determination function 31e of the work analysis unit 31 determines that the work part 1a of the work implement 1 is not a normal work position. 4 is provided. The notification unit 4 allows a worker who is working to confirm the determination information that the work position is not a normal work position by sound by a sound generator such as a speaker. Note that the notification unit 4 is not limited to auditory confirmation, but may allow a worker who is working to visually confirm the information on a display device that displays determination information that the work position is not a normal work position. The determination information that the work position is not normal may be confirmed using the sound generation device and the display device.

  When the three-dimensional coordinate data received from the two magnetic sensors 2A and 2B has a data format different from the coordinate data for the data processing device, the two magnetic sensors 2A, A data format conversion unit 31g that converts the three-dimensional coordinate data received from 2B into the data format of the coordinate data of the data processing device 3 may be incorporated. When the three-dimensional coordinate data received from the two magnetic sensors 2A and 2B is the same as the data format of the coordinate data of the data processing device 3, the data format conversion unit 31g does not convert the data format and converts the three-dimensional coordinate data. Is processed by the work analysis unit 31. Although the data format conversion unit 31 f is shown as a function of the work analysis unit 31 in FIG. 1, the data format conversion unit 31 f may be disposed between the two magnetic sensors 2 </ b> A and 2 </ b> B and the work analysis unit 31.

  Each configuration of the data processing device 3 in the work position determination device configured as described above is realized by a program executed by the arithmetic processing device. The data processing procedure by this program will be described based on the flowchart of FIG.

  A nut runner is used as the work implement 1. Further, the predetermined operation by the nut runner 1 is such that a part such as a brake hose is screwed to the lower part of the chassis Ch using the nut runner 1 as shown in FIG.

  First, the operator selects a predetermined operation to be performed by the data processing device 3, that is, an operation for screwing a brake hose or the like to a lower part of the chassis Ch of the automobile lifted by the lift Li. Keep going. When the worker starts a predetermined work on the nutrunner 1 (step 101), the work analysis unit 31 of the data processing device 3 stores reference data corresponding to the predetermined work in the reference database registered in the storage unit 32. Is selected (step 102).

  When the work analysis unit 31 receives the respective three-dimensional coordinate data detected by the two magnetic sensors 2A and 2B of the nutrunner 1 (step 103), the data matching function 31d of the work analysis unit 31 includes two magnetic sensors. Data matching is performed between each three-dimensional coordinate data output from 2A and 2B and each three-dimensional coordinate data of each three-dimensional coordinate data group of each magnetic sensor 2A and 2B included in the selected reference data ( Step 104).

  This data matching function 31d is used to output the respective three-dimensional coordinate data output from each magnetic sensor 2A, 2B of the work implement in a predetermined work and the respective three-dimensional coordinate data of each magnetic sensor 2A, 2B included in the reference data. Data matching is performed using a difference value with each group of three-dimensional coordinate data. The calculation of the difference value can be obtained by the following equations (1) and (2).

Here, the equation (1) is to obtain a difference value of the magnetic sensor 2A, d is a difference value, xn, yn, zn are each three-dimensional coordinate data of the three-dimensional coordinate data group of the magnetic sensor 2A, x1, y1, z1 is three-dimensional coordinate data at the time of measurement by the magnetic sensor 2A.

  Here, the equation (2) is to obtain the difference value of the magnetic sensor 2B, d is the difference value, xn, yn, zn are each three-dimensional coordinate data of the three-dimensional coordinate data group of the magnetic sensor 2B, x2, y2, z2 is three-dimensional coordinate data at the time of measurement by the magnetic sensor 2B.

  When data matching is performed by the data matching function 31d, the work position determination function 31e of the work analysis unit 31 determines the work position (step 105). When the data matching is performed as a result of the data matching performed by the data matching function 31d, the work position determination function 31e determines that the work position of the work part 1a of the nutrunner 1 is a normal work position. Therefore, the worker can perform normal screwing work at the work position. Note that the work analysis unit 31 feeds back to step 103 when the operator has not performed the work end operation on the data processing device 3.

In addition, when the work position determination function 31e determines that the work position of the work part 1a of the nutrunner 1 is not a normal work position as a result of performing the data matching by the data matching function 31d, an alarm is given from the notification unit 4. Inform (step 106). That is, since it can be confirmed that the work position to be screwed is not the normal position, the operator changes the position, tilt and push-in degree of the nut runner 1 to correct the work position of the work part 1a of the nut runner 1 to the normal work position. be able to.
It should be noted that the operator can finish the predetermined work by performing the work end operation on the data processing device 3 (step 107).

  Next, a data processing procedure by a program for creating a reference database will be described based on the flowchart of FIG. In order to create the reference database, a skilled worker performs a screwing operation to screw parts such as a brake hose on the lower part of the vehicle using the nut runner 1.

  First, a reference database is used to perform a predetermined operation to be performed by the operator in the data processing device 3, that is, an operation for screwing a brake hose or the like to a lower part of the chassis Ch of the automobile lifted by the lift Li. Perform the operation so that it can be registered.

  Then, in order for the skilled worker to create a reference database corresponding to the predetermined work by the nutrunner 1, predetermined normal work ranges on the virtual spherical surfaces of the respective magnetic sensors 2A, 2B corresponding to the predetermined work The nutrunner 1 is swung around the work site 1a as a swing center so that the skilled worker draws a predetermined locus (step 201). In this way, when the nutrunner 1 is swung, the data collection function 31a of the work analysis unit 31 collects data for collecting a plurality of three-dimensional coordinates measured on a predetermined locus for each of the magnetic sensors 2A and 2B ( Step 202).

  When the collection data is collected in step 202, the reference data creation function 31b of the work analysis unit 31 performs the collection of the three-dimensional coordinate collection data of each point collected in step 202 for each of the magnetic sensors 2A and 2B. By performing cubic interpolation, each three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual sphere on which a three-dimensional coordinate value missing in a predetermined normal working range on the virtual sphere is calculated, Reference data is created by associating the moving center 1a with a straight line (step 203).

  Finally, the reference data created in step 204 is made into a database, thereby completing the work of creating the reference database (steps 204 and 205). The reference data that is databased in step 204 can be databased for different operations.

  As described above, according to the above-described embodiment, the two magnetic sensors 2A and 2B are arranged on the nut runner 1 at different distances from the work site 1a, with the work site 1a determined in advance in the nut runner 1 as the swing center. Therefore, in the screwing operation in which the work part 1a of the nut runner 1 is the swing center, each magnetic sensor 2A, 2B has the radius as the distance between the swing center 1a and each magnetic sensor 2A, 2B. The three-dimensional coordinate data of the three-dimensional coordinate data group on each virtual sphere of each magnetic sensor 2A, 2B is associated with the swing center 1a in a straight line. When the work position to be screwed is a normal position, the three-dimensional coordinate data output from the magnetic sensors 2A and 2B and the reference data Murrell and 3-dimensional coordinate data of a three-dimensional coordinate data group of each of the magnetic sensors is that data matching. Therefore, the worker can understand that the work position of the work part (swing center) 1a of the nutrunner 1 moved by himself / herself is a normal work position.

  As described above, in the work position determination system and the work position determination method of the present invention, it is highly accurate that the work position of the work part (swing center) 1a of the nutrunner 1 moved by the worker himself is a normal work position. This is because the magnetic field distribution is always stable even if the magnetic field due to the transmitter is distorted by arranging the metal body in the vicinity of the position where the work is actually performed. By associating the three-dimensional coordinate data on each virtual sphere 2B and the oscillation center 1a in a straight line, the position where the operation is performed without correcting the measurement error of the position coordinates caused by the distortion of the magnetic field can be determined. Whether or not the position is correct can be determined with high accuracy.

  Therefore, even if there are a plurality of work positions where the worker screws with the nut runner 1 in close proximity, if the data processing device 3 performs the processes in steps 201 to 205 at each work position, the work is actually performed. When the data processor 3 performs the processing of steps 101 to 105 to determine whether or not the position is correct, it can be determined with high accuracy whether or not the nut runner 1 has been moved to an incorrect work position.

  In the above-described embodiment, the two magnetic sensors are disposed on the work implement at different distances from the predetermined work site of the work implement. However, the present invention is not limited to this. These magnetic sensors may be arranged on the work implement at different distances from a predetermined work site of the work implement. In this case, the greater the number of magnetic sensors associated with the oscillation center, the higher the measurement accuracy.

  In the above-described embodiments, the nutrunner is used as the work implement. However, the present invention is not limited to this, and any work implement may be used as long as the work portion of the work implement is centered on the swing. For example, spot welding with a welding gun, material fixing with a screwdriver and a nailer, and the like can be mentioned.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

1 …… Nutrunner (working equipment)
2A, 2B …… Magnetic sensor 4 …… Notification unit 31 …… Work analysis unit 31a …… Data collection function 31b …… Reference data creation function 31c …… Reference database creation function 31d …… Data matching function 31e …… Work position determination Function VS1, VS2 ... Virtual spherical surface

102 …… Reference data selection step 104 …… Data matching step 105 …… Work position determination step 202 …… Data collection step 203 …… Reference data creation step 204 …… Reference database creation step

Claims (7)

At least two magnetic sensors disposed on the work implement at different distances from a predetermined work site of the work implement;
Each of the magnetic sensors can move on a virtual spherical surface having a radius as a distance between the swing center and the magnetic sensor when the magnetic sensor swings around the work site as a swing center. Each of the three-dimensional coordinate data groups on the virtual spherical surface of each magnetic sensor when the work site is swung around the rocking center within a predetermined normal working range on the virtual spherical surface. Reference data in which three-dimensional coordinate data and the rocking center are associated with each other in a straight line is a reference database in which a database is created for each different operation;
When a predetermined work is started by the work implement, the reference data corresponding to the predetermined work is selected from the reference database, each three-dimensional coordinate data output from each magnetic sensor, and the reference Data matching is performed as a result of data matching performed by the data matching function using the data matching function and a data matching function that performs data matching with each 3D coordinate data of the 3D coordinate data group of each of the magnetic sensors included in the data. In this case, the work position determination system includes a work analysis unit having a work position determination function for determining that the work position of the work part of the work implement is the normal work position.   The work analysis function of the work analysis unit includes a notifying unit that issues a warning when it is determined that the work position of the work part of the work implement is not the normal work position. The work position determination system according to claim 1, wherein: The work analysis unit
In order to create the reference database corresponding to the predetermined work by the work implement, within the predetermined normal work range on the virtual spherical surface of each of the magnetic sensors corresponding to the predetermined work, When the operator for creating the reference data swings the work implement with the work site as the swing center so as to draw a predetermined trajectory, each magnetic sensor is measured on the predetermined trajectory. A data collection function for collecting data for collecting a plurality of three-dimensional coordinates,
For each magnetic sensor, the predetermined normal working range on the virtual sphere is obtained by performing cubic interpolation on the data for collecting the three-dimensional coordinates of the points collected by the data collecting function. The reference data is generated by associating each of the three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual sphere on which the missing three-dimensional coordinate value is calculated and the swing center in a straight line. Reference data creation function,
The work position determination system according to claim 1 or 2, further comprising a reference database creation function for creating a database of the reference data created for each different work by the reference data creation function. In the work implement, at least two magnetic sensors are arranged at different distances from a predetermined work site of the work implement, and each of the magnetic sensors has the work site as a swing center. When the robot swings, it can move on a virtual spherical surface whose radius is the distance between the swing center and the magnetic sensor, and receives the respective three-dimensional coordinate data output from each magnetic sensor. A work position determination method for estimating a normal work position of the work part based on each of the three-dimensional coordinate data,
The work analysis unit
When a predetermined work is started with the work implement, each of the magnetic sensors when the work part is swung around the swing center within a predetermined normal work range on the virtual spherical surface. Reference data in which each three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual spherical surface and the swing center are associated with each other in a straight line is obtained from a reference database that is databased for each different operation from the predetermined database. A reference data selection step for selecting the reference data corresponding to the work;
Each three-dimensional coordinate data output from each magnetic sensor of the work implement in the predetermined work, and each three-dimensional coordinate data of each three-dimensional coordinate data group of each magnetic sensor included in the reference data A data matching step for data matching with
A work position determination step for determining that the work position of the work part of the work implement is the normal work position when data matching is performed as a result of performing the data matching in the data matching step; A method for discriminating a work position.   And a determination information notifying step for notifying an alarm when it is determined in the work position determining step that the work position of the work part of the work implement is not the normal work position. The work position determination method according to claim 4. The work analysis unit
In order to create the reference database corresponding to the predetermined work by the work implement, within the predetermined normal work range on the virtual spherical surface of each of the magnetic sensors corresponding to the predetermined work, When the operator for creating the reference data swings the work implement with the work site as the swing center so as to draw a predetermined track, the magnetic sensor is measured on the predetermined track. A data collection step for collecting data for collecting a plurality of three-dimensional coordinates;
For each magnetic sensor, the predetermined normal working range on the virtual sphere is obtained by performing cubic interpolation on the data for collecting the three-dimensional coordinates of the points collected in the data collecting step. The reference data is generated by associating each of the three-dimensional coordinate data of the three-dimensional coordinate data group on the virtual sphere on which the missing three-dimensional coordinate value is calculated and the swing center in a straight line. A reference data creation step;
6. The work position determination method according to claim 4, further comprising a reference database creation step of creating a database of the reference data created for each different work in the reference data creation step.   The data matching step includes the three-dimensional coordinate data output from each magnetic sensor of the work implement in the predetermined work, and the three-dimensional coordinate data group of each magnetic sensor included in the reference data. 7. The work position determination method according to claim 4, wherein data matching is performed using a difference value with each of the three-dimensional coordinate data.

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