JP7565845B2 - Location estimation system and location estimation method - Google Patents

Description

This disclosure relates to a location estimation system and a location estimation method.

Conventionally, steel products in which metal sheets such as steel sheets are wound into a cylindrical shape (coil shape) are temporarily stored in warehouses, etc., and the coils are carried in and out using loading and unloading equipment. When storing these coils, sleepers are used on the floor on which the coils are placed to prevent the cylindrical coils from rolling. By stacking the coils on these sleepers, it becomes possible to store multiple coils. Patent Document 1 discloses a loading and unloading operation determination device for placing products to be stored using fixed platforms as sleepers.

JP 2016-222455 A

The loading and unloading operation determination device disclosed in Patent Document 1 stores information identifying the position of the fixed platform (sleeper) in a database in advance, and products to be stored are loaded and unloaded based on this position information. However, the size of the coil varies depending on the length of the metal being supplied and the thickness of each piece. Therefore, the position of the sleeper needs to be changed depending on the coil to be placed. For example, with the loading and unloading operation determination device disclosed in Patent Document 1, every time the position of the sleeper is changed, the position of the sleeper needs to be manually remeasured and registered in the database, which is time-consuming.

Therefore, the present disclosure aims to provide a position estimation device and a position estimation method that can efficiently estimate the position of a sleeper on which a coil is placed.

One aspect of the present disclosure is a position estimation system that estimates the position of a pair of fixed tables installed on a floor surface for placing a cylindrical or columnar load, the system comprising: markers installed on both ends of the extension direction of the fixed tables; a moving mechanism that is located at the upper part in a direction perpendicular to the floor surface and moves on a plane parallel to the floor surface; a sensor that is installed on the moving mechanism and collects position information of the markers and detection information indicating whether the marker has been detected; a drive control unit that controls the moving mechanism to cause the sensor to collect the position information and the detection information; a sensor information acquisition unit that acquires the position information and detection information collected by the sensor; a position information calculation unit that calculates, for each of two fixed tables constituting the pair of fixed tables, first position information of a marker installed at one end of the extension direction of the fixed tables and second position information of a marker installed at the other end of the extension direction of the fixed tables based on the position information and the detection information; and a central position calculation unit that calculates a central position of the pair of fixed tables based on an average value of the two first position information and the two second position information for the pair of fixed tables.

The pair of markers may be fixed in parallel with a distance equal to the installation interval in the short side direction of the pair of fixed bases, and may be positioned by contacting the fixed bases. In the above position estimation system, the length of the marker in the extension direction of the fixed base may be longer than the length of the marker in the short side direction of the fixed base. The sensor includes a detection sensor that detects relative position information and detection information of the marker, and a position sensor that collects the position of the moving mechanism as position information, and the sensor information acquisition unit acquires the relative position information, detection information, and position information of the moving mechanism, and calculates coordinate information of the marker based on the relative position information and the position information of the moving mechanism, and the position information calculation unit calculates first position information and second position information based on the coordinate information and detection information. The marker may be configured in a shape that can distinguish the pair of fixed bases from another pair of fixed bases. Furthermore, the marker may have a portion with high reflectivity, and the position information calculation unit may calculate the first position information and the second position information from the distribution of the measured measurement points with high reflectivity.

Another aspect of the present disclosure is a position estimation method executed by a computer, the method including: a control process for controlling a moving mechanism having a sensor that collects information about markers installed on both ends of a first direction, which is an extension direction of a pair of fixed tables installed for placing a cylindrical or columnar load, the information being position information of the markers and detection information indicating whether the marker has been detected, to move in a second direction perpendicular to the first direction; a sensor information acquisition process for acquiring the position information and detection information collected by the sensor; a first position information calculation process for calculating, as first position information, the position information of the marker installed on one end of the fixed table collected by the sensor for each of the two fixed tables constituting the pair of fixed tables; a second position information calculation process for calculating, as second position information, the position information of the marker installed on the other end of the fixed table collected by the sensor for each of the two fixed tables constituting the pair of fixed tables ; and a central position calculation process for calculating a central position of the pair of fixed tables based on an average value of the two first position information and the two second position information for the pair of fixed tables.

This disclosure provides a position estimation device and a position estimation method that can efficiently estimate the position of a sleeper on which a coil is placed.

1 is a diagram illustrating a schematic configuration of a position estimation system according to an embodiment. 1 is a schematic diagram for explaining a position sensor provided in a trolley according to one embodiment. FIG. 1 is a schematic diagram illustrating an example of an object detection sensor according to an embodiment, in which an object is detected in the YZ direction; 1 is a schematic diagram illustrating an example of an object detection sensor according to an embodiment, in which an object is detected in the XZ directions; 1 is a block diagram showing a schematic configuration of a position estimation device according to an embodiment. FIG. 1 is a block diagram illustrating a functional configuration of a position estimation system according to an embodiment. FIG. 2 is a diagram illustrating an example of sensor information stored in a sensor information DB. 1 is a diagram for explaining the positions of markers and the center positions of sleepers in a position estimation system according to an embodiment; FIG. 2 is a diagram showing an example of location information stored in a location information DB. 11 is a flowchart illustrating an example of a process related to information acquisition by a sensor according to an embodiment. 10 is a flowchart illustrating an example of a calculation process for the center position of a sleeper according to an embodiment. 13A to 13C are diagrams showing other forms of marker members and marker reflecting portions according to other embodiments. 13A to 13C are diagrams showing other forms of marker members and marker reflecting portions according to other embodiments.

Below, exemplary embodiments will be described with reference to the drawings. Here, the dimensions, materials, and other specific values shown in the embodiments are merely examples, and do not limit this disclosure unless otherwise specified. Furthermore, elements having substantially the same functions and configurations are given the same reference numerals to avoid duplicated explanations, and elements that are not directly related to this disclosure are not illustrated.

Figure 1 is a schematic perspective view showing the configuration of a position estimation system 1 according to one embodiment. In this embodiment, the position estimation system 1 estimates the position of a sleeper on which a load is placed that is transported by an overhead crane installed at the top in a direction perpendicular to the floor surface inside a building such as a factory or warehouse. In this embodiment, the sleeper corresponds to a fixed platform.

In this embodiment, the cargo to be transported by the overhead crane is, for example, a steel plate coil (hereinafter simply referred to as "coil") made by winding a thin steel plate into a cylindrical or columnar shape. Multiple coils C are temporarily stored on site within the building. The overhead crane hoists and moves the coils C, allowing the coils C to be transported from another location to the site and vice versa.

The site also has a floor surface represented as an XY plane. The coils C are installed on the side of the floor surface with the central axis of each coil C parallel to the floor surface. In this embodiment, when the coils C are installed on the side of the floor surface, the axial direction of each coil C is along the Y direction. When the coils C are installed on the side of the floor surface, each coil C is aligned along the X direction perpendicular to the Y direction. In this case, the cross-sectional direction of the coil C is along the X direction. Furthermore, the coils C are stacked in two stages along the Z direction perpendicular to the XY plane. Of these, the coils C on the lower stage are placed on the floor surface via two rod-shaped sleepers 200 that constitute a set. The extension direction of the sleepers 200 is along the axial direction of the coils C. Furthermore, the two sleepers that constitute a set are adjacent to each other in the cross-sectional direction of the coils C. Such a set of sleepers 200 can position the coils C to be placed and can also prevent the coils C from rolling. On the other hand, the upper coils C are placed on the lower coils C while being directly supported by the two lower coils C adjacent to each other in the X direction.

Furthermore, in this embodiment, a marker member 300 used to estimate the center position of the sleeper 200 can be installed on both ends of the extension direction (Y direction) of the sleeper 200. That is, a pair of marker members 300 are fixed in parallel with a distance equal to the installation interval in the short direction (X direction) of the pair of sleepers 200. In addition, the marker member 300 can be installed in contact with the sleeper 200. By installing the marker member 300 in contact with the sleeper 200 in this manner, the accurate center position of the sleeper 200 can be estimated based on the measured position of the marker member 300. In addition, a marker reflecting portion 310 is provided on the upper surface of the marker member 300. The marker reflecting portion 310 is used when detecting the marker reflecting portion 310 by the sensor 6 described later. In this embodiment, the length of the marker reflector 310 in the Y direction (extension direction of the sleeper 200) is longer than the length of the marker reflector 310 in the X direction (short side direction of the sleeper 200). In this embodiment, the marker reflector 310 corresponds to a marker. Details of the sensor 6, the marker member 300, and the marker reflector 310 will be described later.

As shown in FIG. 1, the overhead crane in the position estimation system 1 includes a girder 2, a runway 3, a trolley 4, a tong 5, a sensor 6, and a cab 7.

The girder 2 is a structure that supports the trolley 4 movably near the ceiling inside the building. The girder 2 includes two linear rigid parts that each extend along a second direction on the XY plane and face each other while being spaced apart in a first direction perpendicular to the second direction on the XY plane. In this embodiment, as an example, the second direction is the X direction and the first direction is the Y direction. In this case, the two rigid parts are integrated with each other on both sides of one end and the other end in the X direction (not shown). At least one end of the girder 2 in the X direction is equipped with a girder actuator 25 such as a motor (see FIG. 5).

The runway 3 is a travel lane that supports the girder 2 for free movement near the ceiling inside the building. The runways 3 extend along the Y direction and are installed at two positions facing each other while being spaced apart in the X direction. The runway 3 may be installed, for example, on the wall 8 of the building (see FIG. 2 ) or on an elevated platform installed on the floor surface inside the building. One end of the girder 2 in the X direction is located on one runway 3, and the other end of the girder 2 in the X direction is located on the other runway 3. The girder actuator 25 is driven based on a movement command from the cab 7, allowing the girder 2 to move along the runway 3 in the Y direction.

The trolley 4 is a structure that is supported by two rigid parts on the girder 2 and can move freely along the X direction, and supports the tongs 5 so that they can move freely along the Z direction. The trolley 4 is equipped with a trolley actuator 26 (see FIG. 5) such as a motor. The trolley actuator 26 is driven based on a movement command from the driver's cab 7, so that the trolley 4 can move along the X direction on the rigid part of the girder 2. In addition, since the girder 2 can move along the Y direction, the trolley 4 can move to a target position on the XY plane. In this embodiment, the trolley 4 and the girder 2 correspond to a moving mechanism.

The tongs 5 are gripping parts that grip the coil C and move up and down. Here, the trolley 4 is equipped with a rotating drum (not shown) for hoisting and lowering the tongs 5 via a wire rope (not shown), and a tong actuator (not shown) such as a motor that applies a rotational force to the rotating drum. The tong actuator is driven based on a lift command from the cab 7, so that the tongs 5 can move along the Z direction based on the height position of the trolley 4.

The tongs 5 also includes a base 10 and a pair of arms, a first arm 11a and a second arm 11b. The base 10 is connected to a wire rope and supports the first arm 11a and the second arm 11b. The first arm 11a and the second arm 11b each extend downward from the base 10 in the Z direction and face each other in the Y direction. The first arm 11a is connected to one end of the base 10 in the Y direction, and the second arm 11b is connected to the other end of the base 10 in the Y direction. The first arm 11a and the second arm 11b can each slide along the Y direction while maintaining a posture along the Z direction.

The sensor 6 is installed on at least one of the structures within the movement range of the trolley 4, and includes a position sensor 6a that measures the position of the trolley 4 on the XY plane. The sensor 6 also includes a detection sensor 6b that detects an object on the floor surface side. Here, the movement range of the trolley 4 refers to the range of the XY area in which the trolley 4 can move in the X and Y directions. The structure within the movement range of the trolley 4 refers to, for example, the trolley 4 itself, the base 10 of the tongs 5, or the rigid part of the girder 2. However, regardless of which structure the sensor 6 is installed on, it is installed in a position where it can detect the position of the trolley 4 and the floor surface below. In this embodiment, the sensor 6 is installed on the trolley 4. In this case, if the sensor 6 is installed on the trolley 4, especially on the side, there is an advantage that the detection range is less likely to be blocked by the tongs 5 supported by the trolley 4.

In this embodiment, the position sensor 6a is a laser distance sensor that uses a laser to measure distance. However, there are no limitations on the type of sensor 6 as long as it can measure the distance to an object. For example, an image sensor such as a TOF (Time-Of-Flight) camera may be used as the position sensor 6a in place of what is generally known as a distance sensor.

Figure 2 is a diagram for explaining the measurement of the position of the trolley 4 by the position sensor 6a. As shown in Figure 2, the position sensor 6a measures the distance between the runway 3 in the X direction on the side of the trolley 4 on which the sensor 6 is provided. This measurement makes it possible to measure the distance in the X direction at which the trolley 4 is located. In other words, it is possible to measure the position of the trolley 4 in the X direction.

As shown in FIG. 2, the position sensor 6a measures the distance to the wall 8 in the Y direction. This measurement makes it possible to measure the distance in the Y direction where the trolley 4 is located. In other words, the position of the trolley 4 in the Y direction can be measured. Note that the method of using a laser as a means for measuring the position of the trolley 4 does not limit the configuration of this embodiment. For example, a means for measuring the position of the trolley 4 may be used that uses an image sensor such as the above-mentioned TOF camera, an encoder, or a beacon. The position information of the trolley 4 (X-direction distance, Y-direction distance) acquired by the position sensor 6a is sent to the driver's cab 7.

Furthermore, as shown in Figs. 3A and 3B, the sensor 6 includes a detection sensor 6b that detects an object on the floor side. In this embodiment, two LiDARs (Light Detection and Ranging) are used to detect an object on the floor side. The example shown in Figs. 3A and 3B shows an example of detecting a coil C on the floor side.

The example shown in FIG. 3A shows an example of detecting an object in the axial direction (Y direction) of coil C. Also, the example shown in FIG. 3B shows an example of detecting an object in the circumferential direction (X direction) of coil C. Detection sensor 6b detects object detection information and relative position information from detection sensor 6b. The object detection result acquired by detection sensor 6b is sent to cab 7 together with the above-mentioned position information (X direction distance, Y direction distance). Note that LiDAR as detection sensor 6b does not limit the configuration of this embodiment, and an identification sensor capable of identifying a target object may be used as detection sensor 6b as a sensor other than LiDAR.

In this embodiment, the object on the floor side to be detected by the detection sensor 6b is the marker reflector 310 provided on the marker member 300. That is, the detection sensor 6b detects the position of the marker reflector 310 by using a laser to emit a pulse of light outside the visible spectrum and measuring the time it takes for the pulse to return after being reflected by the marker reflector 310. The object on the floor side to be detected may be, for example, a retroreflective object with high reflectivity, but is not limited to the configuration of this embodiment. For example, the object on the floor side to be detected may be an object that has characteristics that can be clearly distinguished from the outside, such as a part painted with a specific color using a TOF camera, or a part with a specific uneven pattern.

The cab 7 is fixed to one end of the girder 2 and houses the user (operator) who operates the overhead crane. The cab 7 also includes a position estimation device 100 that controls the overhead crane and estimates the position of the sleepers. The position estimation device 100 is realized by a computer such as a personal computer.

(Configuration and Functions of Position Estimation Device 100)
Next, the configuration and functions of the position estimation device 100 will be described. Fig. 4 shows a schematic configuration of the position estimation device 100. Fig. 5 shows a functional configuration of the position estimation device 100 in the position estimation system 1. As shown in Fig. 4, the position estimation device 100 is realized by, for example, a computer, and includes a control unit 110, a storage unit 120, an input/output IF 130, and a network IF 140 as a general computer configuration. The control unit 110 will be described in detail later.

As shown in FIG. 5, the storage unit 120 stores information contained in a sensor information DB 121 (DB: Database) and a location information DB 122 as data. Note that there may be one or more storage units 120 storing these pieces of data. For example, a single storage unit 120 may be configured to store the data in separate areas. Alternatively, the data may be distributed and stored in multiple storage devices installed in physically separate locations.

The input/output IF 130 is, for example, a component (interface) that allows a user (driver) of the cab 7 to exchange data with the position estimation device 100. The input/output IF 130 has an input section and an output section (not shown).

The input section in the input/output IF 130 has an interface function for inputting various information by the user, and information is input from outside the position estimation device 100. Information is input to the input section by the user via, for example, a keyboard, a mouse, a touch panel, a trackball, or a voice recognition device connected to the position estimation device 100. The input section can also input information as a data input terminal for inputting data from an external storage device (not shown) or the like.

The output section of the input/output IF 130 displays the position information of the coil C and sleepers, the work status, etc. on a display device (not shown) connected to the position estimation device 100. The display device is, for example, a display device, a projector device, etc.

The communication IF 140 is an interface that enables mutual communication between the trolley 4 and girder 2 and the position estimation device 100 via a wired and/or wireless network. Specifically, the position estimation device 100 acquires information from the sensor 6 provided on the trolley 4 via the communication IF 140. In addition, the position estimation device 100 sends control instructions via the communication IF 140 to the trolley actuator 26 and the girder actuator 25 provided on the trolley 4 and the girder 2, respectively, to control the trolley 4 and the girder 2.

Next, the flow of control in the position estimation system 1 will be described based on the control block shown in FIG. 5. The position estimation device 100 includes a control unit 110 having a sensor information acquisition unit 111, a position information calculation unit 112, a center position calculation unit 113, and a drive control unit 114 as functions. The control unit 110 also operates an operation system, for example, to control the entire position estimation device 100. Furthermore, the control unit 110 operates based on a program stored in the storage unit 120, and executes each function of the sensor information acquisition unit 111, the position information calculation unit 112, the center position calculation unit 113, and the drive control unit 114. Note that the program is not limited to being stored in the storage unit 120, and may be stored in, for example, a ROM (Read Only Memory) (not shown) in the position estimation device 100.

The sensor information acquisition unit 111 acquires the position information (X-direction distance, Y-direction distance) of the trolley 4 detected by the sensor 6 and sent to the position estimation device 100, detection information indicating whether or not a detection target object on the floor surface has been detected, and relative position information from the trolley 4. Furthermore, the sensor information acquisition unit 111 corrects the relative position information of the detection target with the position information of the trolley 4, and stores the coordinate information converted into absolute coordinates from a fixed point on the ground in the sensor information DB 121. FIG. 6 shows an example of sensor information stored in the sensor information DB 121. As described above, the sensor information includes the X-direction distance, the Y-direction distance, the relative position information of the detection target object from the trolley 4, the coordinate information converted into absolute coordinates from a fixed point on the ground by correcting the relative position information of the detection target with the position information of the trolley 4, and information on object detection. The coordinate information of the detection target object is converted by adding and subtracting the position information of the trolley 4 and the relative position information of the detection target object from the sensor 6. Furthermore, the coordinate information of the detection target object may be subjected to rotation correction or the like depending on the type of the trolley 4.

In the sensor information shown in FIG. 6, when a specific object is detected, a "○" is stored in the "Object Detection" column as information indicating that an object has been detected. In this embodiment, the specific object is the marker reflector 310.

The position information calculation unit 112 calculates the first position information and the second position information based on the coordinate information and detection information of the object to be detected on the floor surface stored in the sensor information DB 121. FIG. 7 shows the positional relationship between the sleeper 200, the marker member 300, and the marker reflecting unit 310. FIG. 7 is a diagram of the sleeper 200 viewed from the ceiling side toward the floor surface. Also, as shown in FIG. 7, the marker members 300 facing each other in the short direction (X direction) of the sleeper 200 are fixed as a pair of marker members 300 by the marker member fixing portion 301. In this way, by providing the marker member fixing portion 301 between the facing marker members 300, it becomes easy to carry the pair of marker members 300 and set them on the sleeper 200. Furthermore, in this embodiment, as shown in FIG. 7, the pair of marker members 300 may be fixed using two or more marker member fixing portions 301. In this way, by using two or more marker member fixing parts 301 for a pair of marker members 300, the pair of marker members 300 can be kept parallel. This allows the sensor 6 to measure the position information of the marker reflecting part 310 more accurately, improving the accuracy of estimating the center position of the sleeper 200.

The calculation of the first position information and the second position information by the position information calculation unit 112 is not limited to a form in which it is performed based on the coordinate information and detection information of the object to be detected on the floor surface stored in the sensor information DB 121. For example, the position information calculation unit 112 may calculate the first position information and the second position information based on the position information (X-direction distance, Y-direction distance) of the trolley 4 stored in the sensor information DB 121, and the relative position information and detection information of the object to be detected on the floor surface.

In this embodiment, the first position information is, for example, information regarding the positions of the marker reflecting unit 310a and the marker reflecting unit 310b shown in FIG. 7. That is, the first position information is position information of the marker reflecting unit 310a and the marker reflecting unit 310b installed at one end side of the extension direction (Y direction) of the sleeper 200. The second position information is information regarding the positions of the marker reflecting units 310c and 310d shown in FIG. 7. That is, the second position information is position information of the marker reflecting unit 310c and the marker reflecting unit 310d installed at the other end side of the extension direction (Y direction) of the sleeper 200.

The position information calculation unit 112 calculates the first and second position information based on the coordinate information of the marker reflector 310 to be detected from the sensor information stored in the sensor information DB 121. Specifically, the position information calculation unit 112 performs a clustering process on the sensor information stored in the sensor information DB 121 and performs grouping on a sleeper basis. This grouping process is performed using, for example, the K-means method. Note that the K-means method as a grouping (clustering) method does not limit this embodiment, and for example, a hierarchical method such as the shortest distance method or Ward's method may be used as a grouping method. For example, in the example shown in FIG. 7, the detected data of the marker reflectors 310a, 310b, 310c, and 310d are grouped in the areas 311a, 311b, 311c, and 311d, respectively. For example, if the marker reflector 310 has a portion with high reflectivity, the position information calculation unit 112 can perform grouping based on the distribution of the measured measurement points with high reflectivity.

The position information calculation unit 112 calculates the center of gravity of each grouped data and stores it in the position information DB 122 in the order of calculation. For example, in the example shown in FIG. 8, two pieces of first position information (Xc1, Yc1) and (Xc2, Yc2) and two pieces of second position information (Xc5, Yc5) and (Xc6, Yc6) are stored for a sleeper with sleeper set number 1. For example, (Xc1, Yc1) is information indicating the center of gravity of the marker reflecting portion 310b included in the area 311b shown in FIG. 7, and (Xc2, Yc2) is information indicating the center of gravity of the marker reflecting portion 310a included in the area 311a shown in FIG. 7. Similarly, (Xc5, Yc5) is information indicating the center of gravity of the marker reflector 310d included in the area 311d shown in FIG. 7, and (Xc6, Yc6) is information indicating the center of gravity of the marker reflector 310c included in the area 311c shown in FIG. 7.

The center position calculation unit 113 calculates the center position of the sleeper based on the position information stored in the position information DB 122. Specifically, the center position calculation unit 113 calculates the center position of the sleeper based on the sleeper set number corresponding to the position information stored in the position information DB 122 and the first position information and the second position information, and stores it in the position information of the position information DB 122. In this embodiment, the center position is a value determined as the average value of the two first position information and the two second position information corresponding to the sleeper set number. The value calculated by the center position calculation unit 113 is estimated as the center position of the sleeper. In the example shown in FIG. 7, the center position 400 is calculated and estimated as the center position of the sleeper.

For example, in the example shown in Figure 8, the center position (C1, C2) of the sleeper with sleeper set number 1 is determined by the following formulas (1) and (2).

C1=(Xc1+Xc2+Xc5+Xc6)/4...(1)
C2=(Yc1+Yc2+Yc5+Yc6)/4...(2)
The drive control unit 114 transmits operation signals to various actuators included in the overhead crane. First, the drive control unit 114 receives, via the input/output IF 130, movement commands to be instructed to the various actuators directly designated by the operator. The location can be received.

Next, the drive control unit 114 can instruct the girder actuator 25 as to the movement position to which the girder 2 is to be moved, and can move the girder 2 to that movement position. The drive control unit 114 can also instruct the trolley actuator 26 as to the movement position to which the trolley 4 is to be moved, and can move the trolley 4 to that movement position.

(Outline of Processing Flow of Position Estimation System 1)
Next, the flow of the position estimation process in the position estimation system 1 will be described using the flowcharts shown in Figures 9 and 10. The flowchart shown in Figure 9 is a flowchart related to the process of acquiring the position information of the trolley 4, the relative position information of the target object, and the detection information of the target object by the sensor 6. The flowchart shown in Figure 10 is a flowchart related to the process of calculating the first and second position information and the center position of the sleeper. The series of operations of the position estimation device 100 shown in the flowcharts of Figures 9 and 10 are started when the position estimation device 100 is started, and the process ends when the work is completed. The process of the flowcharts shown in Figures 9 and 10 is also ended by power off or an interrupt to end the process. In the following description of the flowcharts, the same contents as those described in the description of the position estimation device 100 above will be omitted or simplified.

First, the process of acquiring information by the sensor 6 will be explained based on the flowchart shown in FIG. 9.

In step S901, the drive control unit 114 moves the trolley 4 to the first start point. In this embodiment, the first start point is the upper part in the Z direction of one end of the marker member 300 installed on both ends of the extension direction (Y direction) of the sleeper 200, where the trolley 4 is located on one end of the girder 2 in the X direction (i.e., one runway 3).

In step S902, the drive control unit 114 moves the trolley 4. Specifically, the drive control unit 114 moves the trolley 4 on the girder 2 from the first starting point to which it was moved in step S901 toward the other runway 3. That is, the drive control unit 114 moves the upper part of one end side of the marker member 300 installed on both ends of the extension direction (Y direction) of the sleeper 200 from one side of the runway 3 to the other side along the X direction.

In step S903, the sensor information acquisition unit 111 acquires information sent from the sensor 6 and stores it in the sensor information DB 121. The information acquired by the sensor information acquisition unit 111 is the position information of the trolley 4 (distance in the X direction, distance in the Y direction), relative position information of the target object, and detection information indicating whether the target object has been detected. Furthermore, the sensor information acquisition unit 111 corrects the relative position information of the detection target with the position information of the trolley 4, and stores the coordinate information converted into absolute coordinates from a fixed point on the ground in the sensor information DB 121. In this embodiment, the target object corresponds to the marker reflector 310 provided on the marker member 300.

In step S904, the drive control unit 114 determines whether the trolley 4 has reached the first end point. In this embodiment, the first end point is the location of the other runway 3 where the trolley 4, which started moving from one runway 3 as the first starting point, moves over the girder 2 and reaches. In step S904, if the drive control unit 114 determines that the trolley 4 has reached the first end point (step S904: YES), the process proceeds to step S905. On the other hand, in step S904, if the drive control unit 114 determines that the trolley 4 has not reached the first end point (step S904: NO), the process returns to step S903, and the sensor information acquisition unit 111 acquires sensor information. That is, sensor information is acquired until the trolley 4 reaches the first end point.

In step S905, the drive control unit 114 stops the trolley 4.

In step S906, the drive control unit 114 moves the trolley 4 to the second start point. In this embodiment, the second start point is the upper part in the Z direction of the other end side of the marker member 300 installed on both ends of the extension direction (Y direction) of the sleeper 200, where the trolley 4 is located on one end of the girder 2 in the X direction (i.e., one runway 3).

In step S907, the drive control unit 114 starts moving the trolley 4. Specifically, the drive control unit 114 moves the trolley 4 on the girder 2 from the second starting point to which it was moved in step S906 toward the other runway 3. That is, the drive control unit 114 moves the trolley 4 along the X direction from one side of the runway 3 to the other side, along the upper part of the other end side of the marker member 300 installed on both ends of the extension direction (Y direction) of the sleeper 200.

In step S908, the sensor information acquisition unit 111 acquires information sent from the sensor 6, similar to step S903 described above, and stores it in the sensor information DB 121. The information acquired by the sensor information acquisition unit 111 is the position information of the trolley 4 (distance in the X direction, distance in the Y direction), relative position information of the target object, and detection information indicating whether the target object has been detected. Furthermore, the sensor information acquisition unit 111 corrects the relative position information of the detection target with the position information of the trolley 4, and stores the coordinate information converted into absolute coordinates from a fixed point on the ground in the sensor information DB 121. In this embodiment, the target object corresponds to the marker reflector 310 provided on the marker member 300.

In step S909, the drive control unit 114 determines whether the trolley 4 has reached the second end point. In this embodiment, the second end point is the location of the other runway 3 where the trolley 4, which started moving from one runway 3 that is the second starting point, moves over the girder 2 and reaches. In step S909, if the drive control unit 114 determines that the trolley 4 has reached the second end point (step S909: YES), the process proceeds to step S910. On the other hand, in step S909, if the drive control unit 114 determines that the trolley 4 has not reached the second end point (step S909: NO), the process returns to step S908, and the sensor information acquisition unit 111 acquires sensor information. That is, sensor information is acquired until the trolley 4 reaches the second end point.

In step S910, the drive control unit 114 stops the trolley 4.

In this embodiment, the processes related to steps S903 and S908 correspond to the sensor information acquisition process. Furthermore, among the steps from step S901 to step S910, the processes related to steps other than step S903 and step S908 correspond to the control process.

Next, the process for calculating the first and second position information and the center position of the sleeper will be explained based on the flowchart shown in FIG. 10.

In step S1001, the position information calculation unit 112 calculates the first position information. Specifically, the position information calculation unit 112 calculates the first position information based on the coordinate information of the target object (marker reflector 310) stored in the sensor information DB 121 and the detection information indicating whether the target object has been detected. The position information calculation unit 112 also stores the calculated first position information in the position information DB 122. Note that the process in step S1001 corresponds to the first position information calculation process. Also, the first position information corresponds to the position information of the marker reflector 310 installed on one end side of the extension direction (Y direction) of the sleeper 200. Note that in this embodiment, the first position information is calculated after the movement, but the first position information may be calculated during the movement in step S903. Specifically, the position information calculation unit 112 may directly calculate the first position information from the measurement result of scanning across the sleeper as shown in FIG. 3B, and store it in the position information DB 122.

In step S1002, the position information calculation unit 112 calculates the second position information. Specifically, the position information calculation unit 112 calculates the second position information based on the coordinate information of the target object (marker reflector 310) stored in the sensor information DB 121 and the detection information indicating whether the target object has been detected. The position information calculation unit 112 also stores the calculated second position information in the position information DB 122. Note that the process in step S1002 corresponds to the second position information calculation process. Also, the second position information corresponds to the position information of the marker reflector 310 installed on the other end side of the extension direction (Y direction) of the sleeper 200. Note that in this embodiment, the second position information is calculated after the movement, but the second position information may be calculated during the movement in step S907. Specifically, the position information calculation unit 112 may directly calculate the second position information from the measurement result of scanning across the sleeper as shown in FIG. 3B, and store it in the position information DB 122.

In step S1003, the center position calculation unit 113 calculates the center position of the sleeper based on the first position information and the second position information stored in the position information DB 122. Specifically, the center position calculation unit 113 calculates the center position of the sleeper based on the sleeper set number corresponding to the position information stored in the position information DB 122 and the first position information and the second position information, and stores it in the position information of the position information DB 122. In this embodiment, the center position is a value determined as the average value of the two first position information and the two second position information corresponding to the sleeper set number. The value calculated by the center position calculation unit 113 is estimated as the center position of the sleeper. The process in step S1003 corresponds to a center position calculation process.

In this embodiment, the first position information is collected during the movement from the first starting point to the first end point, and the second position information is collected during the movement from the second starting point to the second end point, but the embodiment is not limited to this process. For example, if the coil C is not placed and the markers at both ends can be measured simultaneously even from directly above the sleeper, only one movement along the center axis of the sleeper may be performed to detect the results of both ends simultaneously. Furthermore, calculation of the first and second position information and calculation of the center position of the sleeper may be performed from the sensor information DB121.

Next, the effects of the position estimation system 1 according to this embodiment will be described.

The position estimation system 1 includes markers installed at both ends of the extension direction of the fixed table, a moving mechanism, a sensor 6, a drive control unit 114 that controls the moving mechanism, a sensor information acquisition unit 111, a position information calculation unit 112, and a center position calculation unit 113. The moving mechanism is located at the upper part in a direction perpendicular to the floor surface and moves on a plane parallel to the floor surface. The sensor 6 collects marker position information and detection information indicating whether the marker has been detected. The sensor information acquisition unit 111 acquires the marker position information and detection information collected by the sensor. The position information calculation unit 112 calculates first position information of the marker installed at one end side of the extension direction of the fixed table and second position information of the marker installed at the other end side of the extension direction of the fixed table based on the marker position information and detection information. The center position calculation unit 113 calculates the center position of the fixed table based on the first position information and the second position information.

Alternatively, a position estimation method executed by a computer includes the following steps. The position estimation method includes a control step of controlling a moving mechanism having a sensor that collects position information of a marker and detection information indicating whether or not the marker has been detected to move in a second direction perpendicular to the first direction. The position information and detection information of the marker are information about markers installed on both ends of the first direction, which is the extension direction of a pair of fixed tables installed to place a cylindrical or columnar load. The position estimation method also includes a sensor information acquisition step of acquiring position information and detection information collected by the sensor. The position estimation method also includes a first position information calculation step of calculating the position information of the marker installed on one end of the fixed table collected by the sensor as first position information. The position estimation method also includes a second position information calculation step of calculating the position information of the marker installed on the other end of the fixed table collected by the sensor as second position information. The position estimation method also includes a center position calculation step of calculating the center position of the fixed table based on the first position information and the second position information.

Here, in this embodiment, the fixed base corresponds to the sleeper 200. Also, in this embodiment, the moving mechanism corresponds to the trolley 4 and the girder 2. Furthermore, the first direction corresponds to the extension direction (Y direction) of the sleeper, and the second direction corresponds to the short side direction (X direction) of the sleeper.

This position estimation system 1 measures the position information of the marker reflectors 310 installed on both ends of the sleepers in the extension direction, and calculates the center position of the sleepers based on this position information, making it possible to more accurately estimate the center position of each pair of sleepers.

In addition, by using a sensor 6 provided on the trolley 4 that transports the coil C, the position estimation system 1 can efficiently acquire the position information of the trolley 4, the relative position information of the marker reflecting unit 310, and the detection information.

The position estimation system 1 also measures the position information of the marker reflectors 310 installed on both ends of the sleeper in the extension direction, and calculates the center position of the sleeper based on this position information. Therefore, the center position of the sleeper can be estimated even when the coil C is placed on the sleeper.

The pair of markers of the position estimation system 1 may be fixed in parallel with a distance equal to the installation interval in the short direction of the pair of fixing bases, and may be installed in contact with the fixing bases. In this embodiment, the markers correspond to the marker reflecting unit 310.

According to this position estimation system 1, by placing the marker member 300 in contact with the sleeper 200 in this manner, the accurate center position of the sleeper 200 can be estimated based on the measured position of the marker member 300.

In addition, in the position estimation system 1, the length of the marker in the extension direction of the fixed base may be longer than the length of the marker in the short side direction of the fixed base. In this embodiment, the marker corresponds to the marker reflector 310.

According to this position estimation system 1, while the trolley 4 moves in the short direction of the sleeper (X direction), the sensor 6 uses a laser to emit pulses of light outside the visible spectrum in the X and Y directions and measures the time it takes for the pulses reflected by the marker reflector 310 to return. In other words, since the marker reflector 310 is detected while the trolley 4 moves in the X direction, the marker reflector 310 is long in the extension direction of the sleeper (Y direction), which enables more accurate detection of the marker reflector 310.

The sensor 6 may also include a detection sensor 6b that detects the relative position information and detection information of the marker, and a position sensor 6a that collects the position of the moving mechanism as position information. The sensor information acquisition unit 111 may also acquire the relative position information, detection information, and position information of the moving mechanism, and calculate coordinate information of the marker based on the relative position information and the position information of the moving mechanism. Furthermore, the position information calculation unit 112 may calculate first position information and second position information based on the coordinate information and detection information.

This makes it possible to more accurately collect relative position information of the marker reflector 310, detect the presence or absence of the marker reflector 310, and measure the position information of the trolley 4 (distance in the X direction, distance in the Y direction). Using this information, the center position of the sleeper 200 can be calculated, making it possible to more accurately estimate the center position.

The marker may also have a portion with high reflectance. Furthermore, the position information calculation unit 112 may calculate the first position information and the second position information from the distribution of the measured measurement points with high reflectance.

This allows accurate detection of markers that have areas with high reflectance. Furthermore, the position information calculation unit 112 can calculate the first position information and the second position information from the distribution of the measured measurement points with high reflectance, thereby enabling more accurate calculation of position information.

Other Embodiments
Although some embodiments have been described, the embodiments can be modified or modified based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined as long as they are not mutually inconsistent.

In the above embodiment, as shown in FIG. 8, the first position information and the second position information are associated with the sleeper set in the calculated order, but the means of association does not limit the configuration of the embodiment. For example, as shown in FIG. 11A, a marker reflector 310e may be provided between a pair of marker members 300 corresponding to a sleeper set. For example, the marker reflector 310e is provided on the upper part of the marker member fixing part 301. The position estimation device 100 may determine that the marker reflector 310 detected before and after the marker reflector 310e is the marker member 300 and the marker reflector 310 corresponding to the same sleeper set. For example, the sensor information DB 121 may be provided with a column for storing information on whether the marker reflector 310e has been detected. The position information calculation unit 112 may calculate the first position information and the second position information based on the X-direction distance, the Y-direction distance, the object detection, and the information detected by the marker reflector 310e in the sensor information DB 121, and may associate the first position information and the second position information with the sleeper set. By providing an additional marker reflector 310e between the marker reflectors 310 in this way to indicate the correspondence with the sleepers, it becomes possible to distinguish between a pair of sleepers and another pair of sleepers.

As shown in FIG. 11B, the width (shape) of the marker member 300 and the marker reflector 310 in the X direction may be changed to detect a pair of marker members 300 in a corresponding sleeper set. As shown in FIG. 11B, by changing the width of the marker reflector 310 in the X direction, the interval at which the information on object detection "○" is stored in the sensor information stored in the sensor information DB 121 is different. The position information calculation unit 112 calculates the first position information and the second position information using the information on the interval at which the information on object detection is stored in addition to the X direction distance, the Y direction distance, and the information on object detection, thereby making it possible to easily match sleeper sets. Furthermore, the position estimation device 100 can prevent errors (mistakes) in matching sleeper sets.

In the above embodiment, the sensor information acquisition unit 111 acquires the position information of the trolley 4, the relative position information of the marker reflector 310 (detection target object), and detection information indicating whether the marker reflector 310 has been detected from the sensor 6. In the above embodiment, the sensor information acquisition unit 111 corrects the relative position information of the marker reflector 310 with the position information of the trolley 4 and calculates coordinate information converted into absolute coordinates from a fixed point on the ground, but the embodiment is not limited to this. For example, a calculation device (not shown) provided on the trolley 4 may correct the relative position information of the marker reflector 310 with the position information of the trolley 4, calculate coordinate information converted into absolute coordinates from a fixed point on the ground, and transmit it to the position estimation device 100. In this case, the sensor information acquisition unit 111 acquires the coordinate information and detection information of the marker member 300 from the sensor 6 and stores them in the sensor information DB 121. For example, the position estimation device 100 can be applied even when the absolute coordinates of the marker member 300 can be acquired by the sensor 6.

In addition, the scope of this embodiment includes a computer program that causes a computer to execute the processing (position estimation method) in the position estimation device 100 described above, and a computer-readable recording medium on which the program is recorded. Here, any type of computer-readable recording medium may be used. In addition, the computer program is not limited to being recorded on the recording medium, and may be transmitted via a telecommunications line, a wireless or wired communication line, a network such as the Internet, or the like.

REFERENCE SIGNS LIST 1 Position estimation system 4 Trolley 6 Sensor 6a Position sensor 6b Detection sensor 111 Sensor information acquisition unit 112 Position information calculation unit 113 Center position calculation unit 114 Drive control unit 300 Marker member 310 Marker reflection unit

Claims (7)

A position estimation system for estimating a position of a pair of fixed platforms installed on a floor surface for placing a cylindrical or columnar load, comprising:
Markers are provided on both ends of the fixing base in the extension direction;
a moving mechanism that is located above the floor surface in a direction perpendicular to the floor surface and moves on a plane parallel to the floor surface;
a sensor provided in the moving mechanism for collecting position information of the marker and detection information indicating whether the marker has been detected;
a drive control unit that controls the moving mechanism so as to cause the sensor to collect the position information and the detection information;
a sensor information acquisition unit that acquires the position information and the detection information collected by the sensor;
a position information calculation unit that calculates, for each of the two fixing bases constituting the pair of fixing bases , first position information of the marker installed on one end side of the fixing base in the extension direction and second position information of the marker installed on the other end side of the fixing base in the extension direction based on the position information and the detection information;
A position estimation system comprising: a central position calculation unit that calculates a central position of the pair of fixed bases based on an average value of the two first position information and the two second position information for the pair of fixed bases. The position estimation system according to claim 1, wherein the pair of markers are fixed in parallel with a distance equal to the installation interval in the short direction of the pair of fixed bases, and can be installed in contact with the fixed base. The position estimation system according to claim 1 or 2, wherein the length of the marker in the extension direction of the fixed base is longer than the length of the marker in the short side direction of the fixed base. the sensor includes a detection sensor that detects relative position information of the marker and the detection information, and a position sensor that collects a position of the moving mechanism as the position information;
the sensor information acquisition unit acquires the relative position information, the detection information, and the position information of the moving mechanism, and calculates coordinate information of the marker based on the relative position information and the position information of the moving mechanism;
4. The position estimation system according to claim 1, wherein the position information calculation unit calculates the first position information and the second position information based on the coordinate information and the detection information. The position estimation system according to any one of claims 1 to 4, wherein the markers are configured in a shape that allows one pair of the fixed bases to be distinguished from another pair of the fixed bases. The marker has a portion having a high reflectivity,
The position estimation system according to any one of claims 1 to 5, wherein the position information calculation unit calculates the first position information and the second position information from a distribution of measurement points having high reflectance. 1. A computer-implemented method for location estimation, comprising:
a control process for controlling a moving mechanism having a sensor for collecting information on markers installed on both ends of a first direction, which is an extension direction of a pair of fixed platforms installed for placing a cylindrical or columnar load, the information being position information of the markers and detection information indicating whether the markers have been detected, so as to move the moving mechanism in a second direction perpendicular to the first direction;
a sensor information acquisition step of acquiring the position information and the detection information collected by the sensor;
a first position information calculation step of calculating, as first position information, the position information of the marker installed on one end side of the fixing base, which is collected by the sensor , for each of the two fixing bases constituting the pair of fixing bases ;
a second position information calculation step of calculating, as second position information, the position information of the marker installed on the other end side of the pair of fixing bases, which is collected by the sensor, for each of the two fixing bases constituting the pair of fixing bases;
a central position calculation step of calculating a central position of the pair of fixing tables based on an average value of the two pieces of first position information and the two pieces of second position information for the pair of fixing tables.

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