CN105811219A - Position aligning method - Google Patents

Abstract

The position alignment method of the present application reduces inherent error factors of various devices caused by dimensional accuracy and the like, and shortens the time required for positioning work per one operation. In the case of assembling the electric wire with the terminal to the connector housing using a plurality of independent working equipment, the positioning error caused by the error factor inherent in each equipment can be reduced by performing calibration in advance. The correction amount corresponding to the inherent error factor of the first device side and the correction amount corresponding to the inherent error factor of the second device side are inserted into the conversion formula for coordinate conversion between the robot coordinate and the world coordinate (S20) . Since the positioning error inherent in the device can be greatly reduced, the time required for position alignment is shortened, and more precise position alignment can be easily performed. The position deviation parallel to each of the X, Y, and Z axis directions, the rotation around each axis, and the correction ratio are determined by measurement (S18).

Description

Position Alignment Method

technical field

The present invention relates to a position alignment method, which is used to move at least the second working equipment by using the first working equipment capable of holding the first device and the second working device capable of holding the second device. The first device is automatically assembled with the second device.

Background technique

For example, an automatic terminal insertion machine disclosed in Patent Document 1 is an operating device for automatically performing an assembly operation for inserting a terminal of an electric wire with a terminal into a connector housing. In this work equipment, the electric wire part of the electric wire with a terminal is held and supported by the holding rod. In addition, a wire guide member is provided between the terminal block on which the terminal is placed and the clamping rod to restrict the lateral swing of the wire portion, and a wire clamp is provided to correct the vertical swing.

That is, in the case of the automatic terminal insertion machine of Patent Document 1, the wires with terminals supported by the clamping rod etc. are aligned relative to the connector housing arranged in a fixed position, and then inserted into the connector. The cavity of the housing is inserted into the terminal, and the wire with the terminal is assembled in the connector housing.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2001-160472

Contents of the invention

The problem that the present invention intends to solve

As in the automatic terminal insertion machine disclosed in Patent Document 1, in the case of carrying out the work of assembling two devices, the two devices are moved using a working robot while the position of one of the two devices is fixed. The other is to align the positions of the two devices, and then perform assembly such as insertion.

For example, when the position of one of the two devices is limited to one position, the position of the other device held by the working robot is managed, and the other device is moved to the target position by a predetermined time by driving the working robot. amount, so that the two devices can be aligned.

However, in an actual device assembly operation, it is necessary to assume complicated situations from the viewpoint of work efficiency, yield, and the like. For example, in the case of manufacturing a wiring harness for a vehicle, since it is necessary to efficiently insert the terminals of the terminal wires into many connector housings with different types and shapes, many connector housings will be placed in different connector housings. In the state where the positions are arranged side by side, the insertion work of the wires with terminals is performed. Therefore, there is a possibility that the position of the connector housing to be inserted is changed every time it is inserted, and it is necessary to align the position of the connector housing and the terminal-provided wire each time.

In addition, when the position of the connector housing to be inserted changes, simply moving the terminal-provided wire by the drive of the working robot cannot perform accurate positional alignment. That is, the movement of a general working robot is in the up-down, left-right, and front-rear directions relative to the working robot itself. When calculating the movement amount of the work robot, etc., it is necessary to perform coordinate transformation and position alignment in three-dimensional space.

In addition, when the work of assembling the terminal-equipped wires into the connector housing is performed, in order to realize a work with a high degree of freedom, a parallel link robot configured by combining a plurality of link mechanisms in parallel is required. Such a parallel link robot can obtain a high degree of freedom in terms of device movement, inclination adjustment, etc., but it is difficult to improve positional accuracy. For example, there may be a relatively large deviation between the designed movement amount and the actual movement amount due to the precision of devices constituting the parallel link robot.

Also, for example, when a large number of connector housings are arranged side by side on a manufacturing table or the like, the actual position of each connector housing may deviate from the designed position due to the accuracy of the manufacturing table or the like.

For example, a working robot or the like uses a camera or the like to automatically recognize the target device at the moving destination from the captured image, thereby automatically correcting the positional deviation and aligning the position correctly. However, when a relatively large positional deviation occurs, the image cannot be recognized correctly, and there is a high possibility that it will take a long time for positional alignment.

For example, in order to perform position alignment with high precision, it is necessary to compare an image captured in a very limited narrow area including the target position with a predetermined reference image. When a large positional deviation occurs, the image cannot be used comparison to fix the position. Alternatively, since the same control is repeatedly performed so that the position is corrected little by little so as to approach the region including the reference image, the time required for position alignment increases.

In addition, in the actual work process, since many devices are placed, and the same work is repeated many times for each device, it will take a long time to assemble all the devices if time-consuming alignment is performed for each operation. Artifacts cannot be manufactured efficiently.

For example, if the inherent error factors of various devices caused by dimensional accuracy and the like can be reduced, the relative position when aligning two devices to be manufactured can reduce the error between the design position and the actual position, and shorten the The time required to perform positioning work per operation, or improve the positioning accuracy.

The present invention was made in view of the above circumstances, and its object is to provide a position alignment method that can reduce the inherent error factors of various equipment caused by dimensional accuracy and the like, and shorten the time required for positioning work per one operation. .

solutions to problems

In order to achieve the above objects, the position alignment method according to the present invention is characterized by the following (1) to (10).

(1) A position alignment method, which is used to: use the first working equipment capable of holding the first device and the second working device capable of holding the second device, at least move the second working device, and perform the operation on the second device. In the operation of automatically assembling the second device with the first device, the position alignment method is characterized in that

When the world coordinates representing the position in the three-dimensional space and the robot coordinates representing the state of the second work equipment exist, they are transformed using a predetermined coordinate transformation formula representing the relationship between the robot coordinates and the world coordinates. As a result of the control amount of the second working equipment, aligning the first device or the first working equipment with the second device or the second working equipment, and,

acquiring a first set of deviation amounts representing deviation amounts of positioning elements of the reference state of the first work equipment,

Acquiring a second group of deviation amounts representing deviation amounts of positioning elements of the reference state of the second work equipment,

A first correction value corresponding to the deviation amount of the first group and a second correction value corresponding to the deviation amount of the second group are brought into the coordinate transformation formula, and the correction result of the deviation amount is obtained as the coordinates The transform result of the transform.

(2) is the position alignment method of the above (1), characterized in that,

As the first working equipment, a circular external shape is used, and a plurality of fixing tables can be arranged side by side on the circumference of the first device,

As the second work equipment, a parallel link robot configured by combining a plurality of link mechanisms in parallel is used.

(3) It is the position alignment method of said (1), It is characterized in that,

As the first device, using a connector housing,

As the second device, an electric wire with a terminal is used.

(4) is the position alignment method of above-mentioned (1), it is characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the second work equipment,

A jig having a predetermined reference hole for calibration is mounted on a fixed part of the second working equipment, and at least the origin position is grasped based on a relative positional relationship between a movable part of the second working equipment and the reference hole for calibration. and actual movement.

(5) It is the position alignment method of said (1), It is characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

One or more sensors are mounted on the movable part of the second working equipment, and the position of the reference point of the first working equipment is measured using the sensors.

(6) is the position alignment method of above-mentioned (5), it is characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

While rotationally driving the circular support member of the first working equipment, each position on the circumference is measured using the sensor, and at least the roundness of the support member is obtained.

(7) is the position alignment method of above-mentioned (5), it is characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

While rotationally driving the circular support member of the first working equipment, each position in the thickness direction of the support member is measured using the sensor, and at least information on the inclination of the support member is acquired.

(8) is the position alignment method of the above (1), characterized in that,

When measuring the relative positional deviation between the first work equipment and the second work equipment,

One or more sensors are mounted on the movable part of the second working equipment, and the movable parts of the second working equipment are positioned at mutually different positions along the outer circumference of the circular support member of the first working equipment. For the same position of more than 3 points, use the sensor to acquire position information at each position of the 3 points.

(9) is the position alignment method of the above (1), characterized in that,

The second group of deviation amounts includes information of a correction ratio indicating a ratio of a theoretical movement amount to an actual movement amount obtained by measurement.

(10) A position alignment method, which is used for: using the first working equipment capable of holding the first device and the second working device capable of holding the second device, at least moving the second working device to perform the operation on the second device. In the operation of automatically assembling the second device with the first device, the position alignment method is characterized in that

When the world coordinates representing the position in the three-dimensional space and the robot coordinates representing the state of the second work equipment exist, they are transformed using a predetermined coordinate transformation formula representing the relationship between the robot coordinates and the world coordinates. As a result of the control amount of the second working equipment, aligning the first device or the first working equipment with the second device or the second working equipment, and,

The positional deviation is corrected by applying the first correction value corresponding to the deviation amount of the first group and the second correction value corresponding to the deviation amount of the second group as constants obtained from previous measurements and applying them to the coordinate transformation formula. , wherein the first group of deviations represents the deviation of the positioning elements of the reference state of the first operating equipment, and the second group of deviations represents the deviation of the positioning elements of the reference state of the second operating equipment .

According to the position alignment method of the configuration of (1) above, when calculating and transforming various control quantities from the robot coordinates to the world coordinates based on the coordinate transformation formula, since the positions of the first working equipment are respectively corrected The first set of deviations due to inherent characteristics (dimensional accuracy, etc.), and the second set of deviations due to inherent characteristics of the second working equipment, so that the positions of the first device and the second device are aligned The position error of the initial state is greatly reduced. Therefore, the positional accuracy when aligning the first device and the second device more precisely from the initial state can be improved, and the time required for the alignment can also be shortened.

According to the position alignment method of the configuration (2) above, a plurality of the first devices can be prepared in advance by using a fixing table having a circular outer shape, and the second devices can be sequentially assembled to these. In addition, by using the parallel link robot, the degree of freedom of the moving path and the like when moving the second device is improved, and the second device can be positioned with respect to the first device arranged at various positions. align. In addition, although the positioning accuracy of the parallel link robot is low, when the coordinate transformation formula is calculated, the position is corrected using the second correction value, so that the decrease in positioning accuracy can be suppressed.

According to the position alignment method of the configuration of the above (3), it is possible to use the first working equipment and the second working equipment to align the position of the connector housing and the electric wire with the terminal, and to align the terminal with the terminal. The terminals of the wires are inserted into the cavities of the connector housing. Therefore, it can be utilized in the process of manufacturing the wiring harness for vehicles, etc.

According to the position alignment method of the configuration of (4) above, using the reference hole for calibration, it is possible to accurately align the movable part of the second working equipment at the origin position, or to grasp the actual movement amount of the movable part. .

According to the position alignment method of the configuration of (5) above, the relative actual positional relationship between the movable portion of the second work equipment and the reference portion of the first work equipment can be accurately grasped using the sensor.

According to the position alignment method of the configuration of (6) above, the out-of-roundness of the support member can be grasped, thereby predicting the positional deviation of the support member in the radial direction relative to the position where the first device is arranged. .

According to the position alignment method of the configuration of (7) above, since the inclination of the support member can be grasped, it is possible to predict the positional deviation of the support member in the thickness direction relative to the position where the first device is arranged.

According to the position alignment method of the configuration of (8) above, since the position information is acquired at each of the positions of the three points, no matter where the first device exists, the movement of the second working equipment Even when the movable part aligns the position of the second device, it is possible to grasp the positional deviation caused by the inherent characteristics of the second working equipment.

According to the position alignment method of the configuration of (9) above, when there is a deviation between the theoretical movement amount and the actual movement amount obtained by measurement, correction can be made based on the information of the correction ratio so that the movement amount deviation elimination.

According to the position alignment method of the configuration of (10) above, since the correction of the first correction value and the second correction value is applied to the coordinate transformation formula using predetermined constants, in the actual manufacturing process When the first device is assembled with the second device, it can be instantly positioned at the correct position, and the correct position excludes the inherent error factor of the first operating device in the initial state and the error factor of the second operating device. inherent error factor. Since the error of the position in the initial state is very small, it is possible to move from this position to a more precise correct position (correction of the position) in a short time. Therefore, due to the improvement in positioning accuracy, the frequency of insertion failures in device assembly operations can be reduced, and the time required for each assembly operation can be further shortened, thereby improving the production efficiency of products.

The effect of the invention

According to the position alignment method of the present invention, the inherent error factors of various devices caused by dimensional accuracy and the like can be reduced, and the time required for the positioning operation performed per operation can be shortened.

The present invention has been briefly described above. Further, details of the present invention will be clarified by reading through the modes for implementing the invention described below (hereinafter referred to as “embodiments”) with reference to the drawings.

Description of drawings

FIG. 1 is a flow chart showing specific steps for performing calibration of the position alignment method of the present invention.

FIG. 2 is a vector diagram showing vectors and coordinate transformations before and after parallel movement between two three-dimensional coordinate systems.

FIG. 3 is a schematic diagram showing the content of a coordinate transformation formula.

4 is a perspective view showing a robot on which a jig is mounted when initial adjustment of the robot coordinate system is performed.

FIG. 5 is a perspective view showing a robot and a fixed stand on which a jig and a sensor are mounted when measuring the fixed stand.

Fig. 6 (A) and Fig. 6 (B) are the perspective views showing the robot and fixed platform that are loaded with fixture and sensor, and Fig. 6 (A) shows the state that measures the radial circumferential position of housing base, and Fig. 6 (B) shows the state where the position of the case base in the thickness direction is measured.

7 is a perspective view showing a state where the terminal insertion head of the robot is positioned at a plurality of positions along the circumference of the housing base.

8 is a perspective view of a terminal insertion device including two parallel joint mechanisms.

Fig. 9 is a perspective view showing the terminal insertion device.

10(A) and 10(B) are views showing a fixing stand of the terminal insertion device, FIG. 10(A) is a plan view of the fixing stand, and FIG. 10(B) is a side view.

Fig. 11 is a side view showing a parallel joint mechanism of the terminal insertion device.

Fig. 12 is a perspective view showing the electric wire carrier of the terminal insertion device.

Explanation of reference signs

10: fixed table

11: Shell receiving part

12: track parts

13: Housing base

14: Motor parts

20: Parallel joint mechanism

21: Base

22a, 22b, 22c: 1st motor

23a, 23b, 23c: arms

24a, 24b, 24c: connecting rod

25: Terminal Insertion Head

25c: Wire clamp

25f: 2nd motor

30: Wire handling machine

31: Carrying track

32: Moving body

33: Transport clamping parts

34: frame

35: Air Chuck Body

40: Terminal measurement sensor

41: Sensor table

51, 52: fixture

53, 54: Contact digital sensor

80: Connector housing

81: chamber

90: wire

91: terminal

detailed description

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In order to facilitate the understanding of the alignment method of the present invention, first, a terminal insertion device, which is a specific manufacturing facility to which the alignment method can be applied, will be described, and then a method of alignment using the terminal insertion device will be described.

[Outline of Terminal Insertion Device]

8 is a perspective view showing a terminal insertion device according to an embodiment of the present invention. The terminal insertion device according to the embodiment of the present invention includes a fixed base 10 and a parallel joint (parallel link) mechanism 20 . The terminal insertion device according to the embodiment of the present invention further includes a wire carrier 30 and a terminal measurement sensor 40 . Next, the fixing table 10, the parallel joint mechanism 20, the electric wire conveyance machine 30, and the terminal measurement sensor 40 will be described in detail.

As shown in FIG. 8 , the two parallel joint mechanisms 20A and 20B respectively insert terminals into different connector housings 80 arranged on the fixing table 10 . In addition, in the case of this structure, the electric wire carrier 30 is provided with two moving bodies 32A and 32B, and the moving body 32A holds one end of the electric wire 90, and the moving body 32B holds the other end of the electric wire 90. Then, the two mobile bodies 32A and 32B convey the electric wire 90 in the state where one end and the other end are held to a predetermined position. In this way, the electric wire conveyance machine 30 conveys electric wire by one circuit line unit. In addition, the measurement sensors of the terminal measurement sensor 40 are attached to the two sensor stands 41. One measurement sensor 47A uses the terminal located at the end of the electric wire held by the parallel joint mechanism 20A as the measurement object, and the other measurement sensor 47B uses the The terminals located at the ends of the electric wires held by the parallel joint mechanism 20B are measurement objects. With this configuration, one of the two parallel joint mechanisms 20A and 20B holds one end of the electric wire 90 and the other holds the other end of the electric wire 90 , and performs terminal insertion processing for different connector housings to which the respective ends are to be connected.

In the terminal insertion device according to the embodiment of the present invention described later, for a deeper understanding, the form in which the terminal is inserted into the connector housing using one parallel joint mechanism 20 will be described, but even if two parallel joint mechanisms are used In the form of inserting the terminals by the mechanisms 20A, 20B, since the two parallel joint mechanisms 20A, 20B are independently driven, the terminal insertion process is also the same.

[Configuration of Terminal Insertion Device]

[Details of fixed table 10]

10(A) and FIG. 10(B) are diagrams showing a fixing stand of a terminal insertion device according to an embodiment of the present invention, FIG. 10(A) showing a plan view of the fixing stand, and FIG. 10(B) showing a side view . As shown in FIGS. 9 and 10(A) and 10(B), the fixing stand 10 is a member for positioning the connector housing 80 and is attached to a flat surface of a housing support stand (not shown). The fixed table 10 includes: a housing receiving portion 11 holding the connector housing 80; an annular rail member 12 on which the housing receiving portion 11 is fixed; Disc-shaped housing base 13 on upper surface 13 a ; motor unit 14 mounted on lower surface 13 b of housing base 13 , with rotating shaft 14 a set so as to coincide with the axis of housing base 13 .

The housing receiving portion 11 has a concave portion formed with an inner surface substantially conforming to the shape of the outer surface of the connector housing 80 . The connector housing 80 is positioned relative to the housing receiving portion 11 by being accommodated in the concave portion of the housing receiving portion 11 . The housing receiving portion 11 is fixed to the rail member 12 via a support base 11 a that supports the housing receiving portion 11 . A part of the support stand 11 a fixed to the rail member 12 extends outside the rail member 12 along the radial direction of the rail member 12 . The case receiving portion 11 is fixed to a part of the support base 11 a extending outside the rail member 12 . In addition, a plurality of casing receiving portions 11 are fixed to the rail member 12 , but these plurality of casing receiving portions 11 are arranged on the annular rail member 12 at predetermined intervals. Therefore, the connector housings 80 fixed to the plurality of housing receiving parts 11 are arranged such that when adjacent connector housings 80 are sequentially connected, a collection of connected line segments forms a ring shape as a whole. In addition, as shown in FIG. 10(A) and FIG. 10(B), the connector housing 80 is held in the housing receiving portion 11 so that the front surface of the connector housing 80 exposed by the opening of the cavity 81 is located on the track member 12. outside. At this time, the extending direction of the cavity 81 of the connector housing held in the housing receiving portion 11 is arranged along the radial direction of the rail member 12 .

The rail member 12 is a flat circular ring member through which the inside of a circular flat plate is penetrated, and is fixed to the case base 13 by fitting a part of the case base 13 inside. The rail member 12 is two semicircular flat plates and is provided on the same plane. Preferably, the rail member 12 in the state where the connector housing 80 is held by the housing receiving portion 11 is fixed to the housing base 13 , and the terminal is inserted into each connector housing 80 .

The casing base 13 is formed by stacking three disk bodies 13c, 13d, and 13e having different diameters so that their axes coincide, and these disk bodies 13c, 13d, and 13e are integrally formed members. The diameter of the disc body 13c is approximately the same as the inner diameter of the rail member 12 . The rail member 12 is fixed with respect to the disk body 13c by fitting the rail member 12 of the disk body 13c. In addition, the diameter of the disk body 13 d is substantially equal to the outer diameter of the rail member 12 . The lower surface of the rail member 12 fixed to the disk body 13c is supported by the upper surface 13a of the disk body 13d, whereby the rail member 12 is stably held with respect to the housing base 13. Moreover, the motor part 14 is attached to the lower surface 13b of the disk body 13e. The axis of the disc body 13 e coincides with the axis of the rotation shaft 14 a of the motor part 14 , and the casing base 13 rotates with the rotation of the motor part 14 . As a result, the rail member 12 fixed to the disk body 13 c of the case base 13 also rotates around the rotation shaft 14 a as the motor member 14 rotates. Therefore, the plurality of connector housings 80 fixed to the respective housing receiving portions 11 also rotate in the circumferential direction of the ring formed by these housings.

The motor unit 14 is supported by the flat surface, and the rotation axis is perpendicular to the flat surface of the case support stand (not shown). The motor unit 14 is supported by the flat surface of the case support stand, whereby the fixed stand 10 is attached to the case support stand. The rotational force of the motor in the motor unit 14 is transmitted to the case base 13 via various gears, and the case base 13 rotates. The motor unit 14 receives a control signal from a predetermined control device (not shown), and controls the rotation of the motor.

In the terminal insertion device according to the embodiment of the present invention, the plurality of connector housings 80 are arranged on the fixing table 10 in an annular shape. Therefore, the terminal insertion device according to the embodiment of the present invention does not need to ensure a space widely spread in the width direction for arranging a plurality of connector housings in a row like a conventional terminal insertion device, but only needs to ensure a width capable of accommodating the fixing table. 10 degrees of space is enough. Therefore, the configuration of the above-described fixing table 10 contributes to miniaturization of the terminal insertion device.

[Details of the parallel joint mechanism 20]

11 is a side view showing a parallel joint mechanism of the terminal insertion device according to the embodiment of the present invention. The parallel joint mechanism 20 is a drive mechanism for a robot for inserting terminals into the connector housing 80 to move the terminal insertion head 25, and is mounted on a parallel joint mechanism support stand (not shown). Parallel joint mechanism 20 as shown in Figure 11, comprises: the base 21 that is installed on parallel joint mechanism supporting platform; 3 the first motors 22a, 22b, 22c that are arranged on the base 21; One end and the first motor 22a respectively The three arms 23a, 23b, 23c driven by being connected to the rotating shafts of , 22b, 22c; the three connecting rods 24a, 24b, each of which is connected to the other end of the arm 23a, 23b, 23c via a universal joint, a transmission gear, 24c; the terminal insertion head 25 connected to the other ends of the three connecting rods 24a, 24b, and 24c via a universal joint. The parallel joint mechanism 20 adjusts the inclination angles of the arms 23a, 23b, 23c and the angles of the links 24a, 24b, 24c relative to the arms 23a, 23b, 23c by controlling the rotation amounts of the three first motors 22a, 22b, 22c. By changing, the terminal insertion head 25 can advance in three directions along XYZ. The parallel joint mechanism 20 receives a control signal from the control device, and controls the rotation of the first motors 22a, 22b, and 22c.

Furthermore, the terminal insertion head 25 has: a hand base 25a connected to the other ends of the three connecting rods 24a, 24b, and 24c via a universal joint; Grasp a part of the electric wire that comprises the terminal that is connected with the end, be provided with the electric wire clamping member 25c of the end of electric wire holding main body 25b; 11 around the X-axis direction), the second motor 25f that rotates in the deflection direction (the direction around the Z-axis in FIG. The third motor 25d that rotates in the direction around the Y-axis in FIG. 11 ; the pressure sensor 25g that detects the external force acting on the wire clamp 25c. In addition, in this embodiment, the second motor 25f and the third motor 25d are provided on the hand base 25a, but the second motor 25f and the third motor 25d may be provided on the base 21. . In this case, the terminal insertion head 25 is rotatable in the pitch direction, the yaw direction, and the roll direction by adopting a structure in which the second motor 25f and the third motor 25d are attached to the hand base 25a via a telescopic shaft and a universal joint. In addition, the electric wire grasping main body 25b is rotated in the pitch direction and the yaw direction by using one second motor 25f, but a structure may be adopted in which two motors corresponding to the second motor 25f are attached to the hand base 25a. One motor rotates the wire holding body 25b freely in the pitch direction, and the other motor rotates the wire holding body 25b freely in the yaw direction.

The wire holding body 25b has a cylinder for sending air to the wire clamp 25c. The wire clamp 25c closes when air is fed from the wire holding body 25b, and opens when no air is fed. The parallel joint mechanism 20 receives the control signal from the control device, and controls the timing of sending air from the electric wire holding body 25b to the electric wire clamp 25c.

Moreover, by controlling the rotation amount of the 2nd motor 25f and driving the electric wire holding main body 25b, the attitude|position of the electric wire holding main body 25b rotates in a pitch direction and a yaw direction. In addition, the wire holding main body 25b has a drive shaft 25e connected to the rotation shaft of the third motor 25d, and by controlling the rotation amount of the third motor 25d and rotating the drive shaft 25e relative to the hand base 25a, the electric wire holding main body 25b can be The pose rotates in the scroll direction. As a result, the attitude of the wire held by the wire clamp 25c also rotates in the pitch direction, yaw direction, and roll direction. The parallel joint mechanism 20 receives the control signal from the control device, and controls the rotation of the second motor 25f and the third motor 25d.

In addition, the wire clamp 25c includes a front chuck 25c1 and a rear chuck 25c2. In the embodiment of the present invention, each chuck 25c1, 25c2 is closed while sandwiching a part of the sheath of the electric wire between the clamps, so that the electric wire clamp 25c holds the electric wire. In this way, when the wire clamp 25c does not need to hold the terminal 91, the terminal clamp for holding the terminal 91 may not be provided in the wire holding main body 25b. Thereby, weight reduction of the wire holding main body 25b is achieved, and further weight reduction of the terminal insertion head 25 is achieved. As a result, the operation speed of the parallel joint mechanism 20 can be improved, the cycle time can be shortened, and the work efficiency of the parallel joint mechanism 20 can be improved.

[the details of wire carrier 30]

Fig. 12 is a perspective view showing a wire carrier of the terminal insertion device according to the embodiment of the present invention. The electric wire conveyance machine 30 is equipment which conveys the electric wire 90 to which the terminal 91 was attached to the predetermined position. As shown in FIG. 12 , the electric wire conveying machine 30 includes: a conveying rail 31 extending along the X-axis direction; a movable body 32 slidably on the conveying rail 31; The terminal insertion head 25 of the moving body 32 ; the frame 34 supporting the conveyance rail 31 ; and the air chuck main body 35 that sends air to the terminal insertion head 25 . In the embodiment of the present invention, the direction in which the moving body 32 moves on the conveyance rail 31 corresponds to the direction of the X-axis.

The moving body 32 includes a motor, and the rotational force of the motor is converted into a propulsion force in the longitudinal direction of the conveyance rail 31 to be able to slide on the conveyance rail 31 . The moving body 32 receives a control signal from the control device to control the rotation of the motor.

The movable body 32 has an air chuck main body 35 for feeding air to the terminal insertion head 25. The clamps are closed when the terminal insertion head 25 is fed with air from the movable body 32, and the clamps are opened when the air is not fed. The movable body 32 receives a control signal from the control device, and controls the timing of sending air to the terminal insertion head 25 .

The position where the parallel joint mechanism 20 grips the electric wire 90 conveyed by the moving body 32 is positioned in advance. That is, the moving body 32 moves on the conveying rail 31 and stops at a predetermined predetermined position, while the parallel joint mechanism 20 directs the electric wires carried by the moving body 32 to the predetermined position. As a result, the parallel joint mechanism 20 can hold the electric wire 90 conveyed by the moving body 32 , while the moving body 32 releases itself from holding the electric wire 90 after the electric wire 90 is held by the parallel joint mechanism 20 . Through this series of processes, the electric wires 90 are supplied to the parallel joint mechanism 20 .

[the details of the terminal measurement sensor 40]

The terminal measurement sensor 40 is a device that measures the rotation angle of the terminal 91 in the rolling direction at the terminal end of the electric wire 90 held by the parallel joint mechanism 20 and the XZ coordinates at which the terminal end 91 is located. In the embodiment of the present invention, the electric wire clamp 25c of the parallel joint mechanism 20 sandwiches the outer sheath of the electric wire 90 at two places, the parallel joint mechanism 20 transports the electric wire 90, and inserts the terminal 91 into the connector housing 80. Chamber 81. At this time, it must be considered that the terminal 91 rotates in the rolling direction. In addition, it is necessary to consider the hanging of the electric wire 90 due to the weight of the terminal 91 or the rebound caused by the crimping of the electric wire, more specifically, the portion of the electric wire 90 grasped from the front side chuck 25c1 of the electric wire clamp 25c. A sag or bounce to the end of the wire 90. The terminal measurement sensor 40 detects the rotation angle of the terminal 91 in the rolling direction and the inclination of the terminal 91 relative to the Y-axis direction due to the hanging or bouncing of the electric wire 90 .

[Position alignment of terminal insertion device]

[Explanation of coordinate transformation]

By the way, in the case of using the terminal insertion head 25 to insert the electric wire with the terminal into each chamber of the connector housing 80 on the fixing table 10, it is necessary to grasp the positional coordinates on the actual three-dimensional space, or all The common position coordinates of the device are used to align the position of the chamber and the terminal. These are world coordinates, and are expressed as coordinates representing positions in the X, Y, and Z axis directions of the three-dimensional space. On the other hand, when the parallel joint mechanism 20 is driven and the robot including the terminal insertion head 25 is moved, it can be controlled using robot coordinates which are coordinates unique to the robot. In the case of the terminal insertion head 25, robot coordinates include a terminal insertion direction (Y), an upward direction (Z), and a direction (X) perpendicular to Y and Z.

Therefore, when moving the terminal insertion head 25 on the robot coordinates, and aligning the position of the wire with the terminal held by the terminal insertion head 25 with the position of the connector housing 80 arranged in three-dimensional space, it is necessary to adjust the control amount of the robot. Transform from robot coordinates to world coordinates.

Figure 2 shows general vector and coordinate transformation before and after parallel movement between two three-dimensional coordinate systems. In addition, the contents of calculation formulas used in general three-dimensional coordinate transformation are as shown in FIG. 3 .

That is, when converting from one of the two coordinate systems represented by the three axes of X, Y, and Z to the other, the vector shown in FIG. 2 changes with parallel movement. In addition, by using the coordinate transformation formula shown in FIG. 3 , it is possible to obtain an accurate transformation result in consideration of the influence of translation and rotation as shown in FIG. 2 accompanying the coordinate transformation.

Actually, by using the determinant of the "homogeneous transformation matrix" shown in FIG. 3 , coordinate transformation between the robot coordinates and the world coordinates can be performed. As shown in FIG. 3 , the "homogeneous transformation matrix" is expressed as the product of the "homogeneous movement matrix" and the "homogeneous rotation matrix". In addition, the "homogeneous rotation matrix" includes each matrix of rotation around the X axis, rotation around the Y axis, and rotation around the Z axis, as shown in FIG. 3 .

Therefore, the control device for controlling the robot can transform the control amount of the robot from the robot coordinates to the world coordinates by calculating the coordinate transformation formula shown in FIG. The position of the electric wire of the terminal is aligned with the position of the connector housing 80 in the actual three-dimensional space.

[Explanation of the positional deviation]

[Position deviation on the robot side]

In the terminal insertion device shown in FIGS. 8 to 12, since the robot that moves the terminal insertion head 25 is driven by the parallel joint mechanism 20, the degree of freedom related to the movement and rotation of the terminal insertion head 25 is high, but the positioning On the contrary, the accuracy tends to decrease.

For example, due to deviations in the dimensional accuracy (length, etc.) of the components of the plurality of links 24a, 24b, and 24c constituting the parallel joint mechanism 20, there is a possibility that the amount of movement in design when the robot moves the terminal insertion head 25, There is a deviation from the actual movement amount. That is, each device has an error factor inherent to the robot. Therefore, if some kind of correction is not performed to eliminate the above-mentioned error factor, it will be difficult to align the position when the error is large.

The error factors on the robot side for moving the terminal insertion head 25 can be represented by seven (1) to (7) listed below.

(1) ΔX: Indicates the deviation amount of the parallel position deviation in the X-axis direction

(2) ΔY: Indicates the amount of deviation of the parallel position deviation in the Y-axis direction

(3) ΔZ: Indicates the amount of deviation of the parallel position deviation in the Z-axis direction

(4) Δα: Indicates the deviation of the rotation around the X axis

(5) Δβ: Indicates the deviation of the rotation around the Y axis

(6) Δγ: Indicates the deviation of the rotation around the Z axis

(7) Cr: Calibration: Ratio = actual movement amount/design movement amount

[Position deviation on the side of the fixed table]

In the terminal insertion device shown in FIGS. 8 to 12 , as shown in FIG. The positions of the cavities of the specific connector housing 80 are aligned to position the terminal-carrying wire held by the wire clamp 25 c of the terminal insertion head 25 .

Therefore, when switching the connector housing 80 of the insertion target of each electric wire with a terminal, the position of the connector housing 80 will change, and the terminal insertion head 25 and the terminal insertion head 25 must be inserted along the circumference of the housing base 13 every time. different positions for positional alignment.

In addition, for example, in the case where alignment is performed with the center of the circle of the housing base 13 as the origin, due to the dimensional error of the radius of the housing base 13 and the roundness of the housing base 13, each connector housing The position where 80 is actually arranged produces a positional deviation in the radial direction (radial direction). Furthermore, when the case base 13 is arranged inclined with respect to a plane parallel to the XY axes, a positional deviation due to the inclination may occur due to a positional difference in the circumferential direction of the case base 13 .

[Explanation of the calibration procedure of the terminal insertion device]

FIG. 1 shows specific steps for implementing the calibration of the position alignment method of the present invention. That is, after installing each device of the terminal insertion device shown in FIGS. 8 to 12 , or after implementing some kind of modification until the manufacture of products is started, in order to eliminate the inherent error factors of each device, the correction procedure shown in FIG. 1 is implemented. homework. Then, this correction step is used to obtain correction data required for correction.

In addition, in the actual calibration work, special jigs for calibration, sensors, etc. are attached and removed manually by the operator, and measurements are performed while moving the movable parts of each device as necessary. The correction data obtained as a result of the measurement is stored in the control device of the terminal insertion device, and can be read out and used when the actual manufacturing process is carried out.

FIG. 4 shows the appearance of the robot on which the jig is mounted when the initial adjustment of the robot coordinate system is performed.

In step S11 of FIG. 1 , jigs necessary for the calibration work are loaded as shown in FIG. 4 by manual work of the operator. In the example shown in FIG. 4 , a jig 51 is mounted on a terminal insertion head 25 which is a movable part of the robot, and a jig 52 is fixed to a base 21 which is a fixed part of the robot. A plurality of calibration reference holes (not shown) are formed in the jig 52 on the fixed side. Specifically, there is one reference hole for calibration indicating the position of the origin; 4 references for calibration are formed at positions offset by 50 [mm] in the positive and negative directions of the X-axis and in the positive and negative directions of the Y-axis, respectively, from the original position. Holes: 4 reference holes for calibration formed at positions deviated by 100 [mm] in the positive and negative directions of the X axis and in the positive and negative directions of the Y axis, respectively, with respect to the origin position.

In step S12 of FIG. 1 , initial adjustment of the robot is performed as described below using jigs 51 and 52 shown in FIG. 4 . First, using the reference hole for calibration on the jig 52 indicating the origin position, drive the parallel joint mechanism 20 and move the position of the terminal insertion head 25 so that the reference position of the jig 51 (protrusion such as a pin) coincides with the reference hole for calibration. At this time, for example, the alignment can be automatically performed using an image captured by a camera (not shown) disposed on the terminal insertion head 25 or the like.

In addition, the position of the two reference holes for calibration deviated from the origin position in the X-axis direction is detected, and the reference direction of the X-axis connecting these is detected, and the movement of the parallel joint mechanism 20 to move the terminal insertion head 25 in the X-axis direction is detected. The inclination (θ1) of the X direction in the case. In addition, the inclination (θ2) in the Z direction is similarly detected.

Further, the parallel joint mechanism 20 is driven to move the terminal insertion head 25 from the position of the reference hole for calibration at the origin to the position of other reference holes for calibration deviated by 100 [mm], and the distance required to actually move 100 [mm] is calculated. The ratio of the amount of driving to the designed driving amount is used as the correction ratio.

FIG. 5 shows the external appearance of the robot and the fixed stand on which the jig and the sensor are mounted when the fixed stand is measured.

In step S13 of FIG. 1 , by manual operation of the operator, as shown in FIG. 5 , two high-precision contact digital sensors 53 and 54 are mounted on the jig 51 of the terminal insertion head 25, and the measurement of the fixed table 10 is performed. preparation.

A contact digital sensor 53 is arranged from the outside of the outer peripheral surface of the housing base 13 toward the center of the housing base 13 as shown in FIG. The position of the radial surface is taken as the relative distance from the terminal insertion head 25 . Another touch-type digital sensor 54, as shown in Figure 5, is disposed near the outer peripheral surface of the housing base 13 from the bottom to the top, that is, in the thickness direction of the housing base 13, and the end is abutted against the lower end surface of the housing base 13. connected, the position of the surface in the vertical direction can be detected. In addition, the procedure may be changed, and the two touch-type digital sensors 53 and 54 may be sequentially mounted one by one, and the measurement may be performed each time.

Figure 6(A) and Figure 6(B) show the appearance of the robot and the fixed table loaded with grippers and sensors, respectively. FIG. 6(A) shows a state in which the radial circumferential position of the case base is measured, and FIG. 6(B) shows a state in which the position in the thickness direction of the case base is measured.

In step S14 of FIG. 1 , as shown in FIG. 6(A), in the state where the end of the contact digital sensor 53 is in contact with the circumferential outer peripheral surface of the housing (HSG) base 13, the driving The motor of the fixed table 10 detects the position in the radial direction with the contact type digital sensor 53 while rotating the casing base 13 . Thereby, the roundness of the shape of the circumference of the case base 13 can be measured.

In step S15 of FIG. 1 , as shown in FIG. 6(B), in a state where the end of the contact digital sensor 54 abuts against the lower end surface near the circumference of the housing (HSG) base 13, the driving The motor of the fixed table 10 detects the change in the position in the thickness direction by the contact type digital sensor 54 while rotating the casing base 13 . Thereby, the inclination of the housing base 13 with respect to the XY plane can be measured.

FIG. 7 shows a state where the terminal insertion head of the robot is positioned at a plurality of positions along the circumference of the housing base.

In step S16 of FIG. 1, the parallel joint mechanism 20 of the robot is moved, and the position and orientation of the terminal insertion head 25 are changed. As shown in FIG. s position. Then, as in S15, the tip of the touch-type digital sensor 54 is brought into contact with the lower end of the case base 13 in the thickness direction, and the relative inclination and height (Z coordinate) of the case base 13 are measured at each point.

In step S17 of FIG. 1, the parallel joint mechanism 20 of the robot is moved, and the position and orientation of the terminal insertion head 25 are changed. As shown in FIG. s position. Then, similar to S14, the tip of the touch-type digital sensor 53 is brought into contact with the outer peripheral surface on the circumference of the housing base 13, and based on the detection value of the touch-type digital sensor 53 measured at each point, the terminal insertion head is determined. 25 and the rotation center position (X, Y coordinates) of the housing base 13.

In step S18 of FIG. 1 , based on the measurement results of S12 to S17, a set of inherent error factors on the robot side that moves the terminal insertion head 25, that is, the ΔX, ΔY, ΔZ, Δα, Δβ, Δγ, and Cr (correction ratio).

In step S19 of FIG. 1 , based on the measurement results of S12 to S17, the inherent error factor groups on the fixed table 10 side are respectively determined, that is, the roundness of the housing base 13 obtained in S14 and the roundness of the housing base 13 obtained in S15. 13 influences such as the inclination.

In step S20 of FIG. 1 , the coordinate transformation formula (refer to FIG. 3 ) used for the coordinate transformation between the robot coordinates of the terminal insertion device and the world coordinates is included to correct the error factor on the robot side determined in S18. Correction value, a correction value for correcting the error factor on the side of the fixing table 10 determined in S19 so that the position of the electric wire with the terminal held by the terminal insertion head 25 in the initial state of the position alignment control is aligned with the position of the connector housing 80 The error is sufficiently small. In addition, the content of the coordinate transformation formula including the correction value in S20 and the data of each correction value are stored, for example, in a nonvolatile memory or a predetermined database so that they can be read and used in an actual manufacturing process.

[Operation of the manufacturing process of the terminal insertion device]

In the manufacturing process of inserting the wires with terminals into the connector housings 80 arranged on the fixing table 10 , alignment is required so that the positions of the terminal ends of the wires 90 substantially coincide with the positions of the cavities of the connector housings 80 . At this time, the control device that drives the parallel joint mechanism 20 and adjusts the position of the terminal insertion head 25, for example, transforms the position of the terminal end of the electric wire 90 from robot coordinates to world coordinates, and aligns the terminal end with the connector housing 80 on the world coordinates. position alignment.

Here, when converting from robot coordinates to world coordinates, by reading and using the coordinate transformation formula incorporating the correction value, it is possible to greatly reduce the error factor inherent in the equipment on the robot side and the equipment inherent in the fixed table 10 side. error factor. That is, the robot can be moved to a position where the relative positional relationship between the terminal end and the connector housing 80 does not greatly deviate from the target value by giving the robot a command value to move the position of the terminal end of the electric wire 90 . Therefore, it is easier to perform precise positional alignment, and the time required for positional alignment can be greatly shortened. Thereby, the cycle time of a manufacturing process can be shortened, and a product can be manufactured more efficiently.

Here, the features of the embodiments of the above-mentioned position alignment method according to the present invention are briefly summarized as [1] to [10] in parallel below.

[1] A position alignment method for a second operation using a first operation device (fixing table 10) capable of holding a first device (connector housing 80) and a second device capable of holding a second device (wire 90) The equipment (parallel link robot 20, terminal insertion head 25) moves at least the second working equipment to automatically assemble the second device on the first device, and the position alignment method is characterized in that

When there are world coordinates representing the position in the three-dimensional space and robot coordinates representing the state of the second work equipment, a predetermined coordinate transformation formula (see FIG. 3) As a result of converting the control amount for the second working equipment, aligning the first device or the first working equipment with the second device or the second working equipment, and,

Acquiring a first set of deviation amounts representing deviation amounts of positioning elements in a reference state of the first work equipment (S19),

Acquiring a second set of deviation amounts representing deviation amounts of positioning elements of the reference state of the second work equipment (S18),

A first correction value corresponding to the deviation amount of the first group and a second correction value corresponding to the deviation amount of the second group are brought into the coordinate transformation formula, and the correction result of the deviation amount is obtained as the coordinates The conversion result of the conversion formula (S20).

[2] The position alignment method according to [1] above, characterized in that,

As the first working equipment, a fixed table (10) having a circular outer shape and capable of arranging a plurality of the first devices side by side on the circumference is used,

As the second working equipment, a parallel link robot (20, 25) configured by combining a plurality of link mechanisms in parallel is used.

[3] The position alignment method according to [1] above, characterized in that,

As the first device, using a connector housing (80),

As the second device, an electric wire (90) with a terminal is used.

[4] The position alignment method according to [1] above, wherein,

When measuring the amount of deviation of the positioning element from the reference state of the second work equipment,

A jig (52) with a predetermined reference hole for calibration is mounted on the fixed part (base 21) of the second operation equipment, based on the relationship between the movable part of the second operation equipment and the reference hole for calibration. With respect to the positional relationship, at least the origin position and the actual movement amount are grasped (see FIG. 4 ).

[5] The position alignment method according to [1] above, wherein,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

One or more sensors (contact digital sensors 53, 54) are mounted on the movable part of the second working equipment, and the position of the reference part of the first working equipment is measured using the sensors (see FIG. 6( A), (B)).

[6] The position alignment method as described in [5] above, characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

While rotationally driving the circular support member (housing base 13) of the first working equipment, the sensor is used to measure each position on the circumference, and at least the roundness of the support member is obtained (see FIG. 6 (A)).

[7] The position alignment method as described in [5] above, characterized in that,

When measuring the amount of deviation of the positioning element from the reference state of the first work equipment,

While rotationally driving the circular support member (13) of the first working equipment, each position in the thickness direction of the support member is measured using the sensor, and at least information on the inclination of the support member is obtained ( Refer to FIG. 6(B)).

[8] The position alignment method according to [1] above, wherein,

When measuring the relative positional deviation between the first work equipment and the second work equipment,

One or more sensors are mounted on the movable part of the second working equipment, and the movable parts of the second working equipment are positioned at mutually different positions along the outer circumference of the circular support member of the first working equipment. For the same three or more points, positional information is acquired using the sensor at each of the three points (see FIG. 7 ).

[9] The position alignment method according to [1] above, characterized in that,

The second group of deviation amounts includes information on a correction ratio (Cr) indicating a ratio of a theoretical movement amount to a measured actual movement amount (S18).

[10] A position alignment method, which is used for: using a first working device (10) capable of holding a first device (80), a second working device (20, 25) capable of holding a second device (90), Moving at least the second working equipment to automatically assemble the second device on the first device, and the position alignment method is characterized in that,

When the world coordinates representing the position in the three-dimensional space and the robot coordinates representing the state of the second work equipment exist, they are transformed using a predetermined coordinate transformation formula representing the relationship between the robot coordinates and the world coordinates. As a result of the control amount of the second working equipment, aligning the first device or the first working equipment with the second device or the second working equipment, and,

The positional deviation is corrected by applying the first correction value corresponding to the deviation amount of the first group and the second correction value corresponding to the deviation amount of the second group as constants obtained from previous measurements and applying them to the coordinate transformation formula. (not shown) wherein, the first group of deviations represents the deviation of the positioning elements of the reference state of the first operating equipment, and the second group of deviations represents the deviation of the positioning elements of the reference state of the second operating equipment .

Claims (10)

1. A position alignment method, which is used for: using a first working device capable of holding a first device and a second working device capable of holding a second device, at least moving the second working device to perform the operation on the second device. In the operation of automatically assembling the second device with the first device, the position alignment method is characterized in that When there are world coordinates representing a position in a three-dimensional space and robot coordinates representing a state of the second work equipment, transform the The conversion result of the control amount of the second working equipment aligns the first device or the first working equipment with the second device or the second working equipment, and, acquiring a first set of deviation amounts representing deviation amounts of positioning elements of the reference state of the first work equipment, Acquiring a second set of deviation amounts representing deviation amounts of positioning elements of the reference state of the second work equipment, A first correction value corresponding to the deviation amount of the first group and a second correction value corresponding to the deviation amount of the second group are brought into the coordinate transformation formula, and the correction result of the deviation amount is obtained as the coordinates The transform result of the transform. 2. position alignment method as claimed in claim 1, is characterized in that, As the first working equipment, a circular external shape is used, and a plurality of fixing tables can be arranged side by side on the circumference of the first device, As the second work equipment, a parallel link robot configured by combining a plurality of link mechanisms in parallel is used. 3. position alignment method as claimed in claim 1, is characterized in that, As the first device, using a connector housing, As the second device, an electric wire with a terminal is used. 4. position alignment method as claimed in claim 1, is characterized in that, When measuring the amount of deviation of the positioning element from the reference state of the second work equipment, A jig having a predetermined reference hole for calibration is mounted on a fixed part of the second working equipment, and at least the origin position is grasped based on a relative positional relationship between a movable part of the second working equipment and the reference hole for calibration. and actual movement. 5. position alignment method as claimed in claim 1, is characterized in that, When measuring the amount of deviation of the positioning element from the reference state of the first work equipment, One or more sensors are mounted on the movable part of the second working equipment, and the position of the reference point of the first working equipment is measured using the sensors. 6. position alignment method as claimed in claim 5, is characterized in that, When measuring the amount of deviation of the positioning element from the reference state of the first work equipment, While rotationally driving the circular support member of the first working equipment, each position on the circumference is measured using the sensor, and at least the roundness of the support member is acquired. 7. position alignment method as claimed in claim 5, is characterized in that, When measuring the amount of deviation of the positioning element from the reference state of the first work equipment, While rotationally driving the circular support member of the first working equipment, each position in the thickness direction of the support member is measured using the sensor, and at least information on the inclination of the support member is acquired. 8. position alignment method as claimed in claim 1, is characterized in that, When measuring the relative positional deviation between the first work equipment and the second work equipment, One or more sensors are mounted on the movable part of the second working equipment, and the movable parts of the second working equipment are positioned at mutually different positions along the outer circumference of the circular support member of the first working equipment. For the same position of more than 3 points, use the sensor to acquire position information at each position of the 3 points. 9. position alignment method as claimed in claim 1, is characterized in that, The second group of deviation amounts includes information of a correction ratio indicating a ratio of a theoretical movement amount to an actual movement amount obtained by measurement. 10. A position alignment method, which is used for: using a first working device capable of holding a first device and a second working device capable of holding a second device, at least moving the second working device to perform the operation on the second device. In the operation of automatically assembling the second device with the first device, the position alignment method is characterized in that When there are world coordinates representing a position in a three-dimensional space and robot coordinates representing a state of the second work equipment, transform the The conversion result of the control amount of the second working equipment aligns the first device or the first working equipment with the second device or the second working equipment, and, The positional deviation is corrected by applying the first correction value corresponding to the deviation amount of the first group and the second correction value corresponding to the deviation amount of the second group as constants obtained from previous measurements and applying them to the coordinate transformation formula. , wherein the first group of deviations represents the deviation of the positioning elements of the reference state of the first operating equipment, and the second group of deviations represents the deviation of the positioning elements of the reference state of the second operating equipment .