Positional relationship detection system

Abstract

To realize a technology that can easily improve the accuracy of the derived stationary detection target quantity even when vibration occurs in the detection target quantity that indicates the relative positional relationship between the holding part and the transfer target location.SOLUTION: A positional relationship detection system 50 includes a measurement unit 51 that measures the positional relationship, a recording unit 52 that records the measurement data obtained by the measurement unit 51 in chronological order, and a calculation unit 53. The calculation unit 53 acquires target time series data, which is time series data of a specific detection target quantity that indicates the positional relationship, based on the measurement data recorded in the recording unit 52. The calculation unit 53 identifies a first peak and a second peak, which are two of a plurality of peaks of a target vibration, which is a vibration of the detection target quantity that appears in the target time series data. The calculation unit 53 calculates an average value of the detection target quantity included in the target time series data between the first peak and the second peak, as a stationary detection target quantity that is a detection target quantity after the target vibration has disappeared.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0003] , ,

[0001] The present invention relates to a position relationship detection system that detects the relative position relationship between a holding unit and a transfer target location in a transfer facility including a transfer device that holds and transfers an object to be transferred by the holding unit and a transfer target location where the object to be transferred is transferred by the transfer device.

Background Art

[0002] An example of the position relationship detection system as described above is disclosed in Japanese Patent No. 6146537 (Patent Document 1). In the following description of this background art, the reference numerals in Patent Document 1 are cited in parentheses. The transfer facility described in Patent Document 1 includes a ceiling traveling vehicle (10) that holds and transfers an object to be transferred by a holding unit (15), and a load port (3) where the object to be transferred is transferred by the ceiling traveling vehicle (10). The position relationship detection system described in Patent Document 1 is configured to detect the relative position relationship between the holding unit (15) and the load port (3) using a teaching unit (20) mounted on the ceiling traveling vehicle (10). Specifically, with the teaching unit (20) disposed above the load port (3), the actual position of the holding unit (15) when the reference position of the load port (3) is taken as the origin, the rotation angle and tilt angle of the holding unit (15) with respect to the reference plane of the load port (3) are detected as detection target amounts indicating the above position relationship.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, vibrations may occur in the detection target quantity, which indicates the relative positional relationship between the holding unit and the transfer target location (load port in Patent Document 1). For example, as described in paragraph 0028 and Figure 6 of Patent Document 1, vibrations occur in the detection target quantity when the teaching unit is shaking above the load port. According to Patent Document 1, when vibrations occur in the detection target quantity in this way, the detection target quantity can be accurately determined by finding the center value of the amplitude of the detection target quantity.

[0005] Patent Document 1 does not disclose a method for determining the center value of the amplitude of the detected quantity, but for example, it is conceivable to determine the center value of the amplitude of the detected quantity by calculating the time average value of the detected quantity. However, the time average value can be different depending on the time range over which the average value is calculated. Therefore, simply calculating the time average value of the detected quantity may not accurately determine the center value of the amplitude of the detected quantity (in other words, the stationary detected quantity, which is the detected quantity after the vibration of the detected quantity has stopped).

[0006] Therefore, there is a need for a technology that can easily improve the accuracy of the derived static detection quantity, even when vibration occurs in the detection quantity that indicates the relative positional relationship between the holding part and the transfer target location. [Means for solving the problem]

[0007] The positional relationship detection system according to this disclosure is a positional relationship detection system for a transporting facility comprising a transporting device that transports an object by holding an object with a holding unit, and a transfer target location where the object is transferred by the transporting device, wherein the system detects the relative positional relationship between the holding unit and the transfer target location, and comprises a measurement unit that measures the positional relationship, a recording unit that records the measurement data obtained by the measurement unit in a time series, and a calculation unit, wherein the calculation unit acquires target time series data, which is time series data of a specific target quantity indicating the positional relationship, based on the measurement data recorded in the recording unit, identifies a first peak and a second peak, which are two of a plurality of peaks of target vibration, which is vibration of the target quantity that appeared in the target time series data, and determines the average value of the target quantity included in the target time series data between the first peak and the second peak as the stationary target quantity, which is the target quantity after the target vibration has disappeared. The transport device is configured to transport an object to be transported to a transfer target location by lowering the holding unit toward the transfer target location, and the direction along the vertical direction is defined as the Z direction, one of the directions perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to both the Z direction and the X direction is defined as the Y direction. The detected target amount includes the X-direction distance, which is the distance in the X direction between the holding reference position, which is the reference position of the holding unit, and the target reference position, which is the reference position of the transfer target location; the Y-direction distance, which is the distance in the Y direction between the holding reference position and the target reference position; and the Z-direction distance, which is the distance in the Z direction between the holding reference position and the target reference position. The calculation unit determines the average value of the detected target amount included in the target time series data between the first peak and the second peak for each of the X-direction distance, the Y-direction distance, and the Z-direction distance as the stationary detected target amount. .

[0008] With this configuration, when calculating the time-averaged value of the detected quantity as a stationary detected quantity (the detected quantity after the vibration of the detected quantity has stopped), the average value is calculated using the target time series data between the first and second peaks. Therefore, the number of data points that deviate positively from the amplitude center value and the number of data points that deviate negatively from the amplitude center value in the target time series data for which the average value is calculated can be made equal (identical or of similar magnitude). This makes it easier to minimize the bias of the average value of the detected quantity towards the positive or negative side of the amplitude center value. Consequently, it is easier to improve the accuracy of the stationary detected quantity derived by the calculation unit. Furthermore, with this configuration, when the conveying device is configured to transfer an object to a transfer location by lowering the holding unit toward the transfer location, it is easier to obtain useful data indicating the relative positional relationship between the holding unit and the transfer location with high accuracy.

[0009] Further features and advantages of the positional relationship detection system will become clear from the following description of embodiments described with reference to the drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Diagram showing a transport equipment according to an embodiment. [Figure 2] Diagram showing a transport device according to an embodiment. [Figure 3] Block diagram showing the positional relationship detection system according to the embodiment. [Figure 4] A diagram showing the detection unit and the unit to be detected according to the embodiment. [Figure 5] A diagram showing the detection unit and the unit to be detected according to the embodiment. [Figure 6] Perspective view of the detected unit according to the embodiment [Figure 7] Diagram illustrating the distance in the X direction, the distance in the Y direction, and the rotation angle of the Z axis. [Figure 8] Diagram illustrating distance in the Z direction and inclination angle in the X direction. [Figure 9] Explanation diagram of distance in the Z direction and inclination angle in the Y direction [Figure 10] A diagram showing an example of time-series data of the detected quantity. [Figure 11] Figure showing another example of time-series data for the detected quantity. [Modes for carrying out the invention]

[0011] An embodiment of the position relationship detection system will be described with reference to the drawings. As shown in Figure 3, the position relationship detection system 50 includes a measurement unit 51, a recording unit 52, and a calculation unit 53. In this embodiment, the detection unit 60 (see Figures 4 and 5), which will be described later, included in the position relationship detection system 50, comprises the measurement unit 51, the recording unit 52, and the calculation unit 53. In contrast to this configuration, the measurement unit 51, the recording unit 52, and the calculation unit 53 can also be provided in multiple hardware components. For example, the measurement unit 51 and the recording unit 52 can be provided in the detection unit 60, and the calculation unit 53 can be provided in the transport device 1 (see Figures 1 and 2), which will be described later. In this case, for example, the functions of the calculation unit 53 can be realized by a control unit 30 (see Figure 2) that controls the transport device 1.

[0012] The positional relationship detection system 50 is used in a transport equipment 100 as illustrated in Figure 1. The transport equipment 100 includes a transport device 1 that transports an object 2 by holding a holding unit 10, and a transfer target location 6 where the transport object 2 is transferred by the transport device 1. The positional relationship detection system 50 detects the relative positional relationship between the holding unit 10 and the transfer target location 6 in the transport equipment 100. The transport object 2 is, for example, a FOUP (Front Opening Unified Pod) that houses semiconductor wafers. The transfer target location 6 is, for example, a load port of a processing device 5 that processes the transport object 2 (or the contents contained in the transport object 2), an in / out port or in / out conveyor of a storage device that stores the transport object 2, or a storage shelf for temporarily storing the transport object 2. The storage shelf is, for example, located above Z1 above the load port of the processing device 5.

[0013] In the following, the direction along the vertical direction will be defined as the Z direction, one of the directions perpendicular to the Z direction will be defined as the X direction, and the direction perpendicular to both the Z and X directions will be defined as the Y direction. One side of the X direction will be defined as the first X direction side X1, and the other side of the X direction will be defined as the second X direction side X2. Similarly, one side of the Y direction will be defined as the first Y direction side Y1, and the other side of the Y direction will be defined as the second Y direction side Y2. In this specification, "along the direction" is not limited to a configuration parallel to the direction, but also includes configurations that are slightly inclined with respect to that direction.

[0014] The conveying device 1 of this embodiment, shown in Figures 1 and 2, is configured as follows. The conveying device 1 comprises a traveling section 41 that travels along a travel path, and a main body section 44 connected to the traveling section 41. The main body section 44 is supported by the traveling section 41, positioned below Z2 relative to the traveling section 41. The object to be conveyed 2 is transported by the conveying device 1 while housed in the main body section 44 (specifically, the internal space of the cover section 45 provided by the main body section 44).

[0015] The travel path along which the traveling unit 41 travels is formed by the rail 4. The traveling unit 41 includes wheels 43 that roll on the traveling surface (here, the upper surface) of the rail 4, and the wheels 43 are rotationally driven by a traveling drive motor 42 (for example, an electric motor such as a servo motor), so that the traveling unit 41 travels along the rail 4. Here, the rail 4 is suspended and supported from the ceiling 3, and the travel path is formed along the ceiling 3. That is, the conveying device 1 is a ceiling conveyor vehicle.

[0016] The conveying device ۱ is configured to transfer the holding unit ۱۰ (specifically, the holding unit ۱۰ holding the transfer object ۲) downward toward the transfer target location ۶ to transfer the transfer object ۲ to the transfer target location ۶. As shown in FIGS. 4 and 5, at the transfer target location ۶, a positioning mechanism ۷ for engaging with the lower part of the transfer object ۲ to position the transfer object ۲ is provided, and the transfer object ۲ transferred from the holding unit ۱۰ to the transfer target location ۶ is arranged at the transfer target location ۶ in a state of being positioned by the positioning mechanism ۷. In FIG. 1, the positioning mechanism ۷ is omitted.

[0017] In the example shown in FIGS. 4 and 5, the positioning mechanism ۷ is configured to engage with the bottom of the lower part of the transfer object ۲ to position the transfer object ۲. Specifically, the positioning mechanism ۷ includes kinematic pins that engage with a recess (for example, a groove-shaped recess) formed in the bottom of the transfer object ۲ that is not shown, and is configured to engage the kinematic pins with the recess to position the transfer object ۲. The configuration of the positioning mechanism ۷ is not limited to this. For example, the positioning mechanism ۷ can be configured to engage with the outer edge of the lower part of the transfer object ۲ to position the transfer object ۲.

[0018] The conveying device 1 is equipped with a lifting device 20 for raising and lowering the holding unit 10. The configuration of the lifting device 20 is not limited to this, but the lifting device 20 in this embodiment is configured as follows. As shown in Figure 2, the lifting device 20 is equipped with a rotating body 21 (for example, a drum), a winding member 22 (for example, a belt or wire) wound around the rotating body 21 so as to be able to be wound up and unwound, and a lifting drive motor 23 (for example, an electric motor such as a servo motor) for rotating the rotating body 21. The lifting device 20 is configured to raise and lower the holding unit 10 by winding up and unwinding the winding member 22 by rotating the rotating body 21 while the holding unit 10 is suspended by the winding member 22. Specifically, the lifting device 20 raises the holding unit 10 by winding up the winding member 22 and lowers the holding unit 10 by unwinding the winding member 22.

[0019] When the transport device 1 performs a travel operation along a travel path, the holding unit 10 is positioned at the travel height. Here, the travel height is the height at which the transport object 2 held by the holding unit 10 is housed in the main body 44 (see Figure 2). When the transport object 2 is transferred between the holding unit 10 and the transfer target location 6, the holding unit 10 is positioned at the transfer height. The transfer height is the height corresponding to the transfer target location 6 (see Figure 1), and is set according to the height of the transfer target location 6.

[0020] As shown in Figures 1 and 2, the holding unit 10 is configured to hold the object to be transported 2 from above Z1. Specifically, the holding unit 10 holds the object to be transported 2 by supporting the flange portion 2a formed on the upper part of the object to be transported 2 with the support member 11. The transport device 1 is equipped with a holding drive motor (not shown, for example, an electric motor such as a servo motor) that drives the holding unit 10, and the holding operation to hold the object to be transported 2 and the holding release operation to release the object to be transported 2 are performed by driving the holding unit 10 with the holding drive motor. In the example shown in Figure 2, the holding drive motor is configured to move a pair of support members 11 closer together and further apart from each other. The holding operation by the holding unit 10 is performed by moving the pair of support members 11 closer together, and the holding release operation by the holding unit 10 is performed by moving the pair of support members 11 further apart from each other. The holding operation and the holding release operation are performed when the holding unit 10 is positioned at the transfer height.

[0021] Although not shown in the figures, the conveying device 1 may be equipped with an adjustment device for adjusting at least one of the following: the horizontal position of the holding part 10, the rotational position of the holding part 10 around the vertical axis along the Z direction, or the inclination angle of the holding part 10 with respect to the horizontal plane. For example, the adjustment device may be configured to include one or both of a moving device that moves the holding part 10 along the width direction and a rotating device that rotates the holding part 10 around the vertical axis. Here, the width direction is the horizontal direction perpendicular to the travel direction of the conveying device 1. In the examples shown in Figures 1 and 2, the X direction is the travel direction and the Y direction is the width direction.

[0022] The moving device is configured, for example, to move the holding part 10 supported by the lifting device 20 along the width direction by moving the lifting device 20 along the width direction. The rotating device is configured, for example, to rotate the holding part 10 supported by the lifting device 20 around the vertical axis by rotating the lifting device 20 around the vertical axis. If the transfer target location 6 is located at a position offset from the travel path of the conveying device 1 in a plan view (view along the Z direction), the conveying device 1 moves the holding part 10 in the width direction using the moving device to a position that overlaps with the transfer target location 6 in a plan view, and then lowers the holding part 10 toward the transfer target location 6 to transfer the conveyed object 2 to the transfer target location 6.

[0023] As shown in Figure 2, the transport device 1 includes a control unit 30 that controls the operation of the transport device 1. The control unit 30 controls the travel drive motor 42 to cause the travel unit 41 to travel along the travel path. The control unit 30 also controls the lifting drive motor 23 to cause the lifting device 20 to perform a lifting operation to raise and lower the holding unit 10. The lifting operation includes an upward operation to raise the holding unit 10 and a downward operation to lower the holding unit 10. The control unit 30 also controls a holding drive motor (not shown) to cause the holding unit 10 to perform a holding operation and a holding release operation. The control unit 30 includes, for example, a processing unit such as a CPU and peripheral circuits such as memory, and each function of the control unit 30 is realized through the cooperation of this hardware and a program executed on the hardware such as the processing unit.

[0024] When transferring the object to be transported 2 between the holding unit 10 and the transfer target location 6, the control unit 30 causes the travel unit 41 to travel the transport device 1 to a target stop position corresponding to the transfer target location 6, with the holding unit 10 positioned at the travel height. The target stop position is set to the same position as the transfer target location 6 in the travel direction (the X direction in the examples shown in Figures 1 and 2). When transferring the object to be transported 2 from the holding unit 10 to the transfer target location 6, the control unit 30 causes the lifting device 20 to perform a descent operation to lower the holding unit 10, which is holding the object to be transported 2, from the travel height to the transfer height. Then, the holding unit 10 releases the object to be transported 2, and then the lifting device 20 performs an ascending operation to raise the holding unit 10, which is no longer holding the object to be transported 2, from the transfer height to the travel height. Furthermore, when transferring the object to be transported 2 from the transfer target location 6 to the holding unit 10, the control unit 30 first causes the lifting device 20 to perform a downward operation to lower the holding unit 10, which is not holding the object to be transported 2, from the travel height to the transfer height, then causes the holding unit 10 to perform a holding operation for the object to be transported 2, and then causes the lifting device 20 to perform an upward operation to raise the holding unit 10, which is now holding the object to be transported 2, from the transfer height to the travel height.

[0025] The target stopping position for the transport device 1 when transferring the object to be transported 2 between the holding unit 10 and the transfer target location 6, and the target amount of movement for the holding unit 10 when transferring the object to be transported 2 between the holding unit 10 and the transfer target location 6, are set to ensure that the object to be transported 2 is transferred appropriately. The control unit 30 obtains the set values ​​for the target stopping position and target amount of movement by referring to a storage device (for example, a storage device provided in the transport device 1), and causes the transport device 1 to perform the transfer operation of the object to be transported 2. The target amount of movement for the holding unit 10 includes, for example, the target lifting amount of the holding unit 10 by the lifting device 20, and the adjustment amount of the holding unit 10 by the adjustment device described above (for example, the target movement amount of the holding unit 10 by the moving device, and the target rotation amount of the holding unit 10 by the rotating device).

[0026] The target stopping position and target movement amount described above are set when the transport equipment 100 is installed. Furthermore, in order to avoid the transport object 2 becoming unable to be properly transferred due to aging or other reasons, the target stopping position and target movement amount are generally adjusted and updated through periodic inspections. The setting and updating of the target stopping position and target movement amount can be performed based on the detection results of the relative positional relationship between the holding unit 10 and the transfer target location 6 by the positional relationship detection system 50. That is, the positional relationship detection system 50 can determine the amount of deviation of the holding unit 10 from the target position (the ideal position for transferring the transport object 2 to the transfer target location 6), and teach can be performed to adjust the target stopping position and target movement amount so that the amount of deviation becomes small. The configuration of the positional relationship detection system 50 of this embodiment will be described below.

[0027] As described above, the position relationship detection system 50 comprises a measurement unit 51, a recording unit 52, and a calculation unit 53. The recording unit 52 records measurement data obtained by the measurement unit 51 in chronological order. The recording unit 52 is equipped with a storage medium (e.g., flash memory) capable of storing and rewriting information. The recording of measurement data to the recording unit 52 is performed by the calculation unit 53. The calculation unit 53 comprises, for example, a processing unit such as a CPU and peripheral circuits such as memory, and each function of the calculation unit 53 is realized through the cooperation of this hardware and a program executed on the hardware such as the processing unit.

[0028] The measuring unit 51 measures the relative positional relationship (hereinafter sometimes simply referred to as "positional relationship") between the holding unit 10 and the transfer target location 6. The position where the holding unit 10 is positioned when the object to be transported 2 is transferred between the holding unit 10 and the transfer target location 6 (in this embodiment, the position where the holding unit 10 performs holding and release operations) is defined as the "transfer position," and the measurement of the positional relationship by the measuring unit 51 is performed, for example, when the holding unit 10 is positioned at a position corresponding to the transfer position (the transfer position, or a position set based on the transfer position but different from the transfer position). In this embodiment, the measurement of the positional relationship by the measuring unit 51 is performed when the transport device 1 is positioned at the target stop position described above, and the holding unit 10 is positioned at a target height set according to the height of the transfer target location 6 (the transfer height described above, or a height set based on the transfer height but different from the transfer height). This target height is, for example, set to a height Z1 above the transfer height by a set height.

[0029] As shown in Figures 4 and 5, in this embodiment, the position relationship detection system 50 comprises a detection unit 60 and a unit to be detected 70. A measurement unit 51, a recording unit 52, and a calculation unit 53 are provided in the detection unit 60. One of the detection unit 60 and the unit to be detected 70 is held by the holding unit 10 in place of the object to be transported 2, and the other of the detection unit 60 and the unit to be detected 70 is placed at the transfer target location 6. The unit to be detected 60 that is held by the holding unit 10 is configured, for example, to have the same weight and center of gravity as the object to be transported 2. Here, "equivalent" means that they are the same to the extent that they can perform the same function, but they do not have to be completely identical.

[0030] As shown in Figures 4 and 5, in this embodiment, the detection unit 60 is held by the holding unit 10, and the unit to be detected 70 is placed at the transfer target location 6. Specifically, the holding unit 10 holds the detection unit 60 by supporting the supported portion 60a formed on the upper part of the detection unit 60 with a support member 11. The shape of the supported portion 60a is, for example, a shape corresponding to the flange portion 2a of the object to be transported 2 (see Figure 2). The unit to be detected 70 is placed at the transfer target location 6 in a positioned state by the positioning mechanism 7. In the example shown in Figures 4 and 5, the kinematic pin of the positioning mechanism 7 engages with a recess (not shown) formed on the bottom of the unit to be detected 70, thereby positioning the unit to be detected 70 relative to the transfer target location 6.

[0031] The measurement unit 51 measures the relative positional relationship between the detection unit 60 and the unit to be detected 70, thereby measuring the relative positional relationship between the holding unit 10 that holds the detection unit 60 and the transfer target location 6 where the unit to be detected 70 is located. Figure 4 shows the state in which the holding unit 10, which holds the detection unit 60, is descending with the unit to be detected 70 located at the transfer target location 6. Figure 5 shows the state in which the holding unit 10, which holds the detection unit 60, has descended to the target height described above, and in this state the positional relationship is measured by the measurement unit 51. The target height is set to a height in which the detection unit 60 and the unit to be detected 70 do not come into contact, as shown in Figure 5.

[0032] As shown in Figure 6, the detection unit 70 comprises a plate-shaped portion 73 and two wall portions (a first wall portion 71 and a second wall portion 72) provided on the upper surface (upper Z1 surface) of the plate-shaped portion 73. The recess into which the kinematic pin engages is formed on the lower surface (lower Z2 surface) of the plate-shaped portion 73. The first wall portion 71 is located on the first side X1 in the X direction of the plate-shaped portion 73, and the second wall portion 72 is located on the second side X2 in the X direction of the plate-shaped portion 73.

[0033] Here, the reference surface of the transfer target location 6 is referred to as the "reference surface S2". The reference surface S2 is a surface (plane) set with reference to the transfer target location 6. For example, the top surface of the transfer target location 6 (the surface on which the transported object 2 is placed) can be the reference surface S2. Any surface set with reference to the transfer target location 6 can be the reference surface S2, including surfaces far from the transfer target location 6 or virtual surfaces. In Figures 6 to 9, the transfer target location 6 is omitted, but in this embodiment, as shown in Figures 6 to 9, the top surface of the detected unit 70 placed at the transfer target location 6 (an example of a surface far from the transfer target location 6) is used as the reference surface S2. The reference surface S2 is designed to be a horizontal plane.

[0034] Furthermore, the reference surface of the holding part 10 is defined as the "holding reference surface S1". The holding reference surface S1 is a surface (plane) set with respect to the holding part 10. Any surface set with respect to the holding part 10, including surfaces far from the holding part 10 or virtual surfaces, can be designated as the holding reference surface S1. Although the holding part 10 is omitted in Figures 8 and 9, in this embodiment, as shown in Figures 8 and 9, the upper surface of the supported part 60a held by the holding part 10 (an example of a surface far from the holding part 10) is designated as the holding reference surface S1. The holding reference surface S1 is designed to be a horizontal plane.

[0035] Furthermore, the reference position of the holding unit 10 is defined as the "holding reference position C1," and the reference position of the transfer target location 6 is defined as the "target reference position C2." The holding reference position C1 is a position set with respect to the holding unit 10. Any position set with respect to the holding unit 10 can be a position away from the holding unit 10 or a virtual position. The target reference position C2 is a position set with respect to the transfer target location 6. Any position set with respect to the transfer target location 6 can be a position away from the transfer target location 6 or a virtual position. In this embodiment, as shown in Figures 8 and 9, the position on the holding reference surface S1 is defined as the holding reference position C1, and the position on the target reference surface S2 is defined as the target reference position C2.

[0036] The holding reference surface S1 and the target reference surface S2 are set so that the relative positional relationship between the holding unit 10 and the transfer target location 6 is ideal and the holding reference surface S1 and the target reference surface S2 are parallel to each other. In addition, the holding reference position C1 and the target reference position C2 are set so that the relative positional relationship between the holding unit 10 and the transfer target location 6 is ideal and the holding reference position C1 and the target reference position C2 overlap in a plan view.

[0037] As shown in Figures 4 and 5, in this embodiment, the detection unit 60 (specifically, the measurement unit 51) is equipped with a distance sensor (for example, a laser distance meter) that measures the distance to the object to be measured, as a sensor that measures the relative positional relationship between the holding unit 10 and the transfer target location 6. Specifically, the detection unit 60 is equipped with six distance sensors: a first sensor 61, a second sensor 62, a third sensor 63, a fourth sensor 64, a fifth sensor 65, and a sixth sensor 66.

[0038] Figure 6 schematically shows the measurement targets of each distance sensor (61-66). As shown in Figure 6, the first sensor 61 measures the distance in the X direction to a plane perpendicular to the X direction on the second wall portion 72. The second sensor 62 measures the distance in the Y direction to a plane perpendicular to the Y direction on the first wall portion 71, and the third sensor 63 measures the distance in the Y direction to a plane perpendicular to the Y direction on the second wall portion 72. The second sensor 62 and the third sensor 63 are positioned at different locations in the X direction. The fourth sensor 64, the fifth sensor 65, and the sixth sensor 66 measure the distance in the Z direction to the upper surface of the plate-shaped portion 73, which is the target reference plane S2. The fourth sensor 64, the fifth sensor 65, and the sixth sensor 66 are positioned at different locations on a plane perpendicular to the Z direction.

[0039] Figure 6 shows the ideal relative positional relationship between the holding unit 10 and the transfer target location 6. In this ideal state, the distance measured by the second sensor 62 and the distance measured by the third sensor 63 are equal to each other. Also in this ideal state, the distance measured by the fourth sensor 64, the distance measured by the fifth sensor 65, and the distance measured by the sixth sensor 66 are all equal to each other.

[0040] The calculation unit 53 determines an index indicating the relative positional relationship between the holding unit 10 and the transfer target location 6 based on the measurement results of each distance sensor (61-66), specifically by calculation (geometric calculation) based on the measurement results of each distance sensor (61-66). Specifically, the calculation unit 53 determines at least one of the following as an index indicating the relative positional relationship between the holding unit 10 and the transfer target location 6: the distance in the X direction ΔX, the distance in the Y direction ΔY, the distance in the Z direction ΔZ, the Z-axis rotation angle θZ, the X-direction tilt angle θX, and the Y-direction tilt angle θY. The calculation method for obtaining these indexes is obvious to those skilled in the art, so a detailed explanation is omitted.

[0041] Figures 7 to 9 show cases where the relative positional relationship between the holding unit 10 and the transfer target location 6 deviates from the ideal state. As shown in Figure 7, the X-direction distance ΔX is the distance in the X direction between the holding reference position C1 and the target reference position C2, the Y-direction distance ΔY is the distance in the Y direction between the holding reference position C1 and the target reference position C2, and the Z-axis rotation angle θZ is the rotation angle around the reference axis A along the Z direction between the holding unit 10 and the transfer target location 6. Here, the axis along the Z direction passing through the target reference position C2 is defined as the reference axis A. Furthermore, as shown in Figures 8 and 9, the distance ΔZ in the Z direction is the distance in the Z direction between the holding reference position C1 and the target reference position C2, the inclination angle θX in the X direction is the inclination of the holding reference surface S1 and the target reference surface S2 in the X direction (in other words, the angle of rotation around the axis along the Y direction), and the inclination angle θY in the Y direction is the inclination of the holding reference surface S1 and the target reference surface S2 in the Y direction (in other words, the angle of rotation around the axis along the X direction).

[0042] Based on the index indicating the relative positional relationship between the holding unit 10 and the transfer target location 6 obtained in this way, the teaching described above can be performed. For example, the detection result (calculation result) of the index indicating the relative positional relationship between the holding unit 10 and the transfer target location 6 is transmitted from the detection unit 60 to the transport device 1 (specifically, the control unit 30) to perform teaching.

[0043] Incidentally, vibrations may occur in the indicator showing the relative positional relationship between the holding unit 10 and the transfer target location 6. In this embodiment, the holding unit 10, which is holding the detection unit 60, is lowered to the target height described above by the unwinding of the winding member 22, and measurement is performed by the measurement unit 51. Therefore, vibrations may occur in the detection result of the detection unit 60 due to the shaking of the holding unit 10 during measurement by the measurement unit 51. The positional relationship detection system 50 of this embodiment has the configuration described below, which makes it possible to accurately determine the center value of the vibration amplitude (i.e., the value after the vibration has stopped) even when vibrations occur in the indicator showing the relative positional relationship between the holding unit 10 and the transfer target location 6.

[0044] In the following, the "detection target quantity" is defined as the average value between the first peak P1 and the second peak P2, as described below, among the indicators showing the relative positional relationship between the holding unit 10 and the transfer target location 6. In this embodiment, the detection target quantity is at least one of the following: X-direction distance ΔX, Y-direction distance ΔY, Z-direction distance ΔZ, Z-axis rotation angle θZ, X-direction tilt angle θX, and Y-direction tilt angle θY. For indicators other than the detection target quantity, the average value can be determined by another method, such as determining the average value over the entire period from the start to the end of measurement. Furthermore, when measuring by the measurement unit 51 while the detection unit 60 is not shaking, such as when the measurement unit 51 is calibrated with the detection unit 60 and the detected unit 70 mounted on a calibration trolley, the average value of the detection target quantity may also be determined over the entire period from the start to the end of measurement.

[0045] Figure 10 shows the time-series data for one detectable quantity from the start to the end of measurement. The recording unit 52 records measurement data obtained by the measurement unit 51 (for example, multiple measurement data acquired at regular time intervals) in time series. In this embodiment, the recording unit 52 records consecutive measurement data (for example, consecutive data at regular time intervals) for a predetermined set period. For example, all measurement data for the set period is recorded in the recording unit 52. This set period is, for example, the period from the start of measurement until a predetermined measurement time has elapsed (in the example shown in Figure 10, the period from the start of measurement to the end of measurement).

[0046] The calculation unit 53 acquires target time-series data, which is time-series data of a specific target quantity indicating its positional relationship, based on the measurement data recorded in the recording unit 52. In this embodiment, the calculation unit 53 acquires target time-series data as illustrated in Figure 10 by calculation (geometric calculation) based on the measurement data recorded in the recording unit 52. For example, the calculation unit 53 performs calculations based on the measurement data recorded in the recording unit 52 in real time and displays the acquired value of the target quantity on the display unit 67 (see Figures 4 and 5) provided on the detection unit 60. In the example shown in Figure 10, the target quantity vibrates such that it has a trough peak at times t1, t3, t5, and t7, and a peak at times t2, t4, and t6.

[0047] The calculation unit 53 identifies two of the multiple peaks of the target vibration, which is the vibration of the target quantity that appeared in the target time series data: the first peak P1 and the second peak P2. Both the first peak P1 and the second peak P2 may be peaks of a mountain or peaks of a trough. In the example shown in Figure 10, both the first peak P1 and the second peak P2 are peaks of a trough. The calculation unit 53 then calculates the average value of the target quantity included in the target time series data between the first peak P1 and the second peak P2 as the static target quantity, which is the target quantity after the target vibration has disappeared. For example, the calculation unit 53 calculates the average value of all the target quantities included in the target time series data between the first peak P1 and the second peak P2 as the static target quantity. The static target quantity calculated by the calculation unit 53 is displayed, for example, in the display unit 67. In the example shown in Figure 10, the period from time t1 corresponding to the first peak P1 to time t7 corresponding to the second peak P2 is set as the average calculation period for calculating the average value of the target quantity. The average value of the detected quantity can be calculated, for example, by dividing the sum of the N values ​​of the detected quantity included in the target time series data by N.

[0048] In the example shown in Figure 10, the number of valley peaks is greater than the number of mountain peaks. Therefore, in the example shown in Figure 10, if we were to calculate the average value of the target quantity included in the target time series data for the entire period from the start to the end of measurement, the average value of the target quantity would be biased to the negative side with respect to the center value of the amplitude of the target quantity. In contrast, by calculating the average value of the target quantity included in the target time series data between the first peak P1 and the second peak P2 as described above, the number of data points that are biased to the positive side with respect to the center value of the amplitude and the number of data points that are biased to the negative side with respect to the center value of the amplitude can be made equal (identical or to the same extent). This makes it easier to keep the bias of the average value of the target quantity to the positive or negative side with respect to the center value of the amplitude small, and as a result, it is easier to improve the accuracy of the stationary target quantity derived by the calculation unit 53.

[0049] However, there are cases where the measurement unit 51 cannot properly measure the positional relationship, such as when the distance from the distance sensor equipped in the measurement unit 51 to the object to be measured is outside the range of distance that the distance sensor can measure. In this case, the value of the detected quantity derived by the calculation unit 53 may be a value outside the expected detection range (i.e., an abnormal value). In view of this, for example, the calculation unit 53 can be configured to use all values ​​of the detected quantity included in the target time series data between the first peak P1 and the second peak P2, excluding values ​​that have been determined to be abnormal based on predetermined judgment conditions, for the calculation of the average value. These judgment conditions may be, for example, a condition in which a value within the expected detection range is determined to be a normal value, and a value outside the detection range is determined to be an abnormal value. Furthermore, for detected quantities that exceed the expected detection range, the upper limit of the detection range may be used as the value of the detected quantity, and for detected quantities that fall below the expected detection range, the lower limit of the detection range may be used as the value of the detected quantity when calculating the average value. Furthermore, for detected quantities that are determined to be outliers, the system can be configured to use an estimated value obtained through interpolation or other means as the value of that detected quantity, and then calculate the average value.

[0050] From the viewpoint of improving the accuracy of the stationary detection target quantity derived by the calculation unit 53, it is preferable that one or more peaks (five peaks in the example shown in Figure 10) are included between the first peak P1 and the second peak P2. In order to ensure a large number of peaks are included between the first peak P1 and the second peak P2, for example, the calculation unit 53 can be configured to identify the earliest peak in the target time series data for a set period (for example, the period from the start of measurement to the end of measurement) as the first peak P1 and the last peak as the second peak P2 (see Figure 10). Note that the first peak P1 and the second peak P2 may be adjacent peaks, in which case one of the first peak P1 and the second peak P2 will be the peak of the mountain, and the other of the first peak P1 and the second peak P2 will be the peak of the valley.

[0051] In this embodiment, the holding unit 10 is lowered from the travel height to a target height set according to the height of the transfer target location 6, and then the measurement unit 51 performs the measurement. In this case, generally, as the amount of descent of the object to be transported 2 to the transfer target location 6 decreases, the vibration period of the holding unit 10 when the transfer target location 6 is the target of measurement becomes shorter. As the vibration period of the holding unit 10 becomes shorter, the vibration period of the amount to be detected also becomes shorter, so that the measurement time of the positional relationship by the measurement unit 51 can be shortened while appropriately ensuring the number of peaks included in the vibration of the amount to be detected. In view of this, for example, the measurement time of the positional relationship by the measurement unit 51 can be set to be shorter in accordance with the amount of descent of the object to be transported 2 to the transfer target location 6 by the lifting device 20 (in other words, in accordance with the amount of descent of the holding unit 10 to the transfer target location 6 by the lifting device 20 becoming smaller). In this case, for example, the measurement time when the load port of the processing device 5 (an example of a transfer target location 6) is the target of measurement is set to be shorter than the measurement time when the storage shelf located above the load port Z1 (another example of a transfer target location 6) is the target of measurement. The measurement time for the positional relationship by the measurement unit 51 is set to be continuously or gradually shortened in accordance with the decrease in the amount of descent.

[0052] Figure 11 shows, with a solid line, the time series data for which the vibration period of the detected quantity is shorter compared to the target time series data shown in Figure 10. Figure 11 also shows, with a dashed line, the target time series data shown in Figure 10. In the example shown in Figure 11, the vibration period of the detected quantity shown by the solid line is half that of the vibration period of the detected quantity shown by the dashed line. In this case, even if the measurement time of the positional relationship by the measurement unit 51 (time from the start of measurement to the end of measurement) is half the measurement time in Figure 10, the number of peaks included in the vibration of the detected quantity can be secured to be about the same as in Figure 10.

[0053] [Other Embodiments] (1) In the above embodiment, the measurement unit 51 was described as having a configuration in which it is equipped with a distance sensor as a sensor for measuring positional relationships. However, the present disclosure is not limited to such a configuration, and the measurement unit 51 may also be equipped with a sensor other than a distance sensor (for example, a camera) as a sensor for measuring positional relationships.

[0054] (2) In the above embodiment, a configuration in which a positioning mechanism 7 is provided at the transfer target location 6 to engage with the lower part of the transported object 2 and position the transported object 2 was described as an example. However, the present disclosure is not limited to such a configuration, and a configuration in which the positioning mechanism 7 is not provided at the transfer target location 6 is also possible. Furthermore, a configuration in which a mechanism for positioning the transported object 2 of a different form than the positioning mechanism 7 is provided at the transfer target location 6 is also possible.

[0055] (3) In the above embodiment, a configuration in which the holding part 10 holds the object to be transported 2 from the upper side Z1 was described as an example. However, the present disclosure is not limited to such a configuration, and for example, the holding part 10 can be configured to hold the object to be transported 2 by supporting it from the lower side Z2. In this case, for example, the transport device 1 can be equipped with an extension / retraction device that extends and retracts (protrudes or retracts) the holding part 10 along the horizontal direction, and the object to be transported 2 can be transported to the transfer target location 6 by lowering the extended holding part 10 toward the transfer target location 6.

[0056] (4) In the above embodiment, the transport device 1 was described as an overhead transport vehicle that travels along a travel path formed along the ceiling 3. However, the disclosure is not limited to such a configuration, and the transport device 1 may be a stacker crane or other railed transport vehicle, or a trackless transport vehicle such as an AGV (Automated Guided Vehicle) or AMR (Autonomous Mobile Robot). When the transport device 1 is a trackless transport vehicle, the transport device 1 travels along a virtually formed travel path rather than a physically formed travel path using rails or the like. For example, multiple detectable objects such as 2D codes or RF (Radio Frequency) tags are placed on the floor, and the travel path is virtually formed to connect the multiple detectable objects. It is also possible to have a configuration in which no such detectable objects are placed on the floor, and the travel path is virtually formed by a route calculated based on the recognition results of the surrounding environment.

[0057] (5) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments (including combinations of embodiments described as other embodiments), as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed in this specification are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0058] [Summary of this embodiment] The following is a summary of the embodiments of the positional relationship detection system described above.

[0059] The position relationship detection system is for a transporting facility comprising a transporting device that transports an object by holding it with a holding unit, and a transfer target location where the transporting device transfers the object, and for detecting the relative position relationship between the holding unit and the transfer target location, comprising a measuring unit that measures the position relationship, a recording unit that records the measurement data obtained by the measuring unit in a time series, and a calculation unit, wherein the calculation unit acquires target time series data, which is time series data of a specific target quantity that indicates the position relationship, based on the measurement data recorded in the recording unit, identifies a first peak and a second peak, which are two of a plurality of peaks of target vibration, which is vibration of the target quantity that appeared in the target time series data, and determines the average value of the target quantity included in the target time series data between the first peak and the second peak as the stationary target quantity, which is the target quantity after the target vibration has disappeared.

[0060] With this configuration, when calculating the time-averaged value of the detected quantity as a stationary detected quantity (the detected quantity after the vibration of the detected quantity has stopped), the average value is calculated using the target time series data between the first and second peaks. Therefore, the number of data points that deviate positively from the amplitude center value and the number of data points that deviate negatively from the amplitude center value in the target time series data for which the average value is calculated can be made equal (identical or of similar magnitude). This makes it easier to minimize the bias of the average value of the detected quantity towards the positive or negative side of the amplitude center value. Consequently, it is easier to improve the accuracy of the stationary detected quantity derived by the calculation unit.

[0061] Here, the transport device is configured to transport an object to be transported to a transfer target location by lowering the holding unit toward the transfer target location, the direction along the vertical direction is defined as the Z direction, one of the directions perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to both the Z direction and the X direction is defined as the Y direction, and the detected target quantity is the distance in the X direction between the holding reference position, which is the reference position of the holding unit, and the target reference position, which is the reference position of the transfer target location, and the distance between the holding reference position and the target Preferably, the holding reference position and the object reference position are at least one of the following: Y-direction distance, which is the distance in the Y direction from the object reference position; Z-direction distance, which is the distance in the Z direction from the holding reference position and the object reference position; Z-axis rotation angle, which is the rotation angle of the holding part and the object to be transferred around a reference axis along the Z direction; X-direction inclination angle, which is the inclination in the X direction between the holding reference surface, which is the reference surface of the holding part, and the object reference surface, which is the reference surface of the object to be transferred; and Y-direction inclination angle, which is the inclination in the Y direction between the holding reference surface and the object reference surface.

[0062] In this configuration, when the conveying device is configured to transfer an object to a transfer location by lowering the holding unit toward the transfer location, it is easier to obtain highly accurate and useful data indicating the relative positional relationship between the holding unit and the transfer location.

[0063] In the above configuration, the conveying device is equipped with a lifting device for raising and lowering the holding portion, the lifting device comprising a rotating body, a winding member wound around the rotating body so as to be able to be wound up and unwound, and a lifting drive motor for rotating the rotating body, the device is configured to raise and lower the holding portion by winding and unwinding the winding member by rotating the rotating body while the holding portion is suspended by the winding member, and it is preferable that the transfer target location is provided with a positioning mechanism that engages with the lower part of the object to be conveyed to position the object to be conveyed.

[0064] In configurations such as this one, where the holding part is suspended and raised and lowered, vibrations of the holding part tend to be large as it moves up and down. For example, when the holding part is lowered to a target height set according to the height of the object to be transferred, and then measurement is performed by the measuring unit, vibrations of the holding part tend to be large when the holding part reaches the target height. In such cases, if measurement is to be performed by the measuring unit after the vibration of the holding part has subsided, the time required for measurement will be longer, resulting in poor detection efficiency of the relative positional relationship between the holding part and the object to be transferred. In this regard, the technology of this disclosure makes it possible to determine a stationary detectable quantity with high accuracy even when the detection quantity is vibrating due to the vibration of the holding part. Therefore, the technology of this disclosure can be suitably applied to configurations in which the holding part is suspended and raised and lowered.

[0065] In the above configuration, it is preferable to set the measurement time of the positional relationship by the measurement unit to be shortened in accordance with the decrease in the amount of descent of the object to be transported to the transfer target location by the lifting device.

[0066] For example, when the holding unit is lowered to a target height set according to the height of the transfer target location, and then measurement is performed by the measuring unit, generally, as the amount of descent of the object to be transported to the transfer target location decreases, the vibration period of the holding unit when the transfer target location is the target of measurement becomes shorter. As the vibration period of the holding unit becomes shorter, the vibration period of the amount to be detected also becomes shorter, so that the measurement time of the positional relationship by the measuring unit can be kept short while ensuring an appropriate number of peaks included in the target vibration. In view of this point, with this configuration, as the amount of descent of the object to be transported to the transfer target location decreases, the measurement time of the positional relationship by the measuring unit is set to be shorter, so that the time required for measurement by the measuring unit can be kept short within the range in which the first peak and the second peak can be appropriately identified, and the time until the stationary amount to be detected can be shortened.

[0067] In the positional relationship detection system of each of the above configurations, the recording unit preferably records the measurement data for a predetermined set period, and the calculation unit preferably identifies the earliest peak in the target time series data for the set period as the first peak and the last peak as the second peak.

[0068] This configuration allows for the calculation of the average value of the target quantity by making maximum use of the measurement data recorded in the recording unit. Therefore, it is easier to further improve the accuracy of the stationary target quantity derived by the calculation unit.

[0069] Furthermore, it is preferable that the calculation unit uses all values ​​of the target quantity to be detected, which are included in the target time series data between the first peak and the second peak, excluding values ​​that have been determined to be abnormal based on predetermined determination conditions, in the calculation of the average value.

[0070] With this configuration, outliers are removed from the values ​​of the target quantity included in the target time series data between the first and second peaks, and all values ​​other than outliers are used in the calculation of the average value. This makes it easier to further improve the accuracy of the stationary target quantity derived by the calculation unit.

[0071] The positional relationship detection system described herein only needs to achieve at least one of the effects described above. [Explanation of Symbols]

[0072] 1: Conveyor device 2: Objects to be transported 6: Sections to be reprinted 7: Positioning mechanism 10: Holding part 20: Lifting device 21: Solid of revolution 22: Component to be wound 23: Lifting drive motor 50: Positional relationship detection system 51: Measurement Unit 52: Records Department 53: Arithmetic section 100: Conveying equipment A: Reference axis C1: Maintain reference position C2: Object reference position P1: No. 1 P2: No. 2 ピーク S1: Maintain reference plane S2: Object reference plane X:X direction Y:Y direction Z:Z direction ΔX: Distance in the X direction ΔY: Distance in the Y direction ΔZ: Distance in the Z direction θX: Inclination angle in the X direction θY: Inclination angle in the Y direction θZ: Z-axis rotation angle

Claims

1. A conveying device comprising a conveying device that holds an object to be conveyed by a holding part and conveys the object, and a transfer target location where the object to be conveyed is transferred by the conveying device, wherein a position relationship detection system detects the relative position relationship between the holding part and the transfer target location, The system comprises a measurement unit for measuring the aforementioned positional relationship, a recording unit for recording the measurement data obtained by the measurement unit in a time series, and a calculation unit. The aforementioned arithmetic unit, Based on the measurement data recorded in the recording unit, target time series data, which is time series data of a specific target quantity indicating the positional relationship, is acquired. The first and second peaks, which are two of the multiple peaks of the target vibration that are the vibrations of the detected quantity that appeared in the target time series data, are identified. The average value of the target quantity to be detected included in the target time series data between the first peak and the second peak is determined as the stationary target quantity to be detected after the target vibration has ceased. The transport device is configured to transfer the object to be transported to the transfer target location by lowering the holding portion toward the transfer target location. Let the direction along the vertical direction be the Z direction, one of the directions perpendicular to the Z direction be the X direction, and the direction perpendicular to both the Z direction and the X direction be the Y direction. The amount to be detected is, The distance in the X direction between the reference position of the holding portion, which is the reference position of the holding portion, and the reference position of the target location to be transferred, which is the distance in the X direction, The distance in the Y direction is the distance between the holding reference position and the target reference position in the Y direction, The distance in the Z direction is the distance between the holding reference position and the target reference position, including the Z-direction distance, The calculation unit determines the average value of the target quantity to be detected included in the target time series data between the first peak and the second peak for each of the X-direction distance, the Y-direction distance, and the Z-direction distance, and uses this as the stationary target quantity to be detected.

2. The amount to be detected is The Z-axis rotation angle is the rotation angle between the holding portion and the transfer target location around a reference axis along the Z direction, The inclination angle in the X direction is the inclination between the holding reference surface, which is the reference surface of the holding part, and the target reference surface, which is the reference surface of the transfer target location, The inclination angle in the Y direction is the inclination between the holding reference surface and the target reference surface in the Y direction, A positional relationship detection system according to claim 1, comprising at least one of the following.

3. The transport device includes a lifting device for raising and lowering the holding portion. The lifting device comprises a rotating body, a member to be wound around the rotating body so as to be able to be wound and unwound, and a lifting drive motor that rotates the rotating body. The device is configured to raise and lower the holding part by winding and unwinding the member to be wound, while the holding part is suspended by the member to be wound. The positional relationship detection system according to claim 2, wherein the transfer target location is provided with a positioning mechanism that engages with the lower part of the object to be transported to position the object to be transported.

4. The recording unit records the measurement data for a predetermined set period. The positional relationship detection system according to any one of claims 1 to 3, wherein the calculation unit identifies the earliest peak in the target time series data for the set period as the first peak and the last peak as the second peak.

5. The positional relationship detection system according to any one of claims 1 to 3, wherein the calculation unit uses all values ​​of the target quantity to be detected, which are included in the target time series data between the first peak and the second peak, excluding values ​​that have been determined to be abnormal based on predetermined determination conditions, in the calculation of the average value.

6. The conveying device comprises a lifting device for raising and lowering the holding portion, The position relationship detection system according to claim 1, wherein the measurement time of the position relationship by the measurement unit is set to be shorter in accordance with the decrease in the amount of descent of the object to be transported to the transfer target location by the lifting device.

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