Distance measuring point group adjustment device, distance measuring point group adjustment method, memory medium

Abstract

To provide a distance measurement point cloud adjustment device, etc., that can effectively prevent false detections. [Solution] The distance measurement point cloud adjustment device 300 includes a distance measurement point cloud acquisition unit 310 that acquires distance measurement point clouds on a measurement target over multiple frames at different times using distance measurement sensors 18 and 19 installed on the CSU 1 that unloads cargo from the cargo hold 201; a thinning unit 340 that thins out some distance measurement points in each frame; and a merged frame generation unit 350 that generates a merged frame by merging the distance measurement point clouds in each frame from which some distance measurement points have been thinned out. The thinning unit 340 thins out a number of distance measurement points equal to the total number of distance measurement points included in each frame multiplied by a predetermined thinning rate. The thinning unit 340 thins out some distance measurement points randomly selected in each frame.

Description

Technical Field

[0001] The present disclosure relates to a ranging point cloud adjustment device that adjusts a ranging point cloud acquired by a ranging sensor installed in a cargo handling machine.

Background Art

[0002] As a cargo handling machine for unloading ship cargo from a ship's hold onto land, a ship unloader for unloading bulk cargo such as coal and iron ore or loose cargo is known. Although the present disclosure is applicable to any cargo handling machine, it will be mainly exemplified and typically described with respect to a ship unloader. A ship unloader is also called a continuous unloader or a continuous ship unloader in the sense that it continuously unloads bulk cargo in a ship's hold. In the present disclosure, its abbreviation CSU is used.

[0003] Patent Document 1 discloses a technique for deriving the relative position between a ship unloader and a ship based on the edge detection result of the upper part of a ship's hold by a ranging sensor (laser sensor). In this technique, the edge is detected based on a series of ranging point clouds acquired through laser light continuously irradiated onto the upper surface and the side wall surface facing the edge of the ship's hold by the ranging sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When unloading by a CSU, there is a risk that the ranging sensor may erroneously detect steam or dust generated from the ship cargo as the ship's hold.

[0006] This disclosure is made in view of these circumstances and aims to provide a distance measurement point cloud adjustment device, etc., that can effectively prevent false detections. [Means for solving the problem]

[0007] To solve the above problems, a distance measuring point cloud adjustment device according to one embodiment of the present disclosure includes: a distance measuring point cloud acquisition unit that acquires a distance measuring point cloud on an object to be measured over multiple frames at different times using a distance measuring sensor installed on a loading machine that unloads cargo from a ship's hold; a thinning unit that thins out some of the distance measuring points in each frame; and a merged frame generation unit that generates a merged frame in which the distance measuring point clouds in each frame from which some of the distance measuring points have been thinned are merged.

[0008] In this embodiment, in order to reduce the influence of non-stationary distance measurement points originating from steam, dust, etc. from cargo, distance measurement points are thinned out in each frame acquired by the distance measurement sensor. In the merged frame formed by combining the frames from which some distance measurement points have been thinned out in this way, distance measurement points on stationary measurement targets such as cargo holds become dominant, thus effectively preventing false detections.

[0009] Another aspect of the present disclosure is a method for adjusting distance measurement point clouds. This method involves acquiring distance measurement point clouds on an object to be measured over multiple frames at different times using distance measurement sensors installed on a loading machine that unloads cargo from a ship's hold, thinning out some distance measurement points in each frame, and generating a merged frame by merging the distance measurement point clouds from each frame from which some distance measurement points have been thinned.

[0010] Another aspect of this disclosure is a storage medium. This storage medium stores a distance measurement point cloud adjustment program that causes a computer to perform the following actions: acquire distance measurement point clouds on an object to be measured over multiple frames at different times using distance measurement sensors installed on a loading machine that unloads cargo from a ship's hold; decimate some distance measurement points in each frame; and generate a merged frame in which the distance measurement point clouds from each frame from which some distance measurement points have been decimated are merged.

[0011] Furthermore, any combination of the above components, as well as any representations thereof converted into methods, apparatus, systems, recording media, computer programs, etc., are also included in this disclosure. [Effects of the Invention]

[0012] According to this disclosure, false detections by distance measuring sensors can be effectively prevented. [Brief explanation of the drawing]

[0013] [Figure 1] This is a front view showing the overall configuration of the lifting machine. [Figure 2] This is a perspective view showing the overall configuration of the lifting machinery. [Figure 3] The detailed configuration of the loading / unloading section is shown. [Figure 4] The appearance of the distance measuring sensor is shown. [Figure 5] This is a top view showing an example of the arrangement of distance measuring sensors. [Figure 6] This is a schematic functional block diagram of the distance measuring point cloud adjustment device. [Figure 7] The various coordinate systems that can be set for CSU are schematically shown. [Figure 8] This shows an example of a frame displayed on a computer screen. [Figure 9] This flowchart shows an example of cargo hold detection using a distance measuring point cloud adjustment device. [Modes for carrying out the invention]

[0014] The following describes in detail the forms (hereinafter also referred to as embodiments) for carrying out this disclosure, with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc., are denoted by the same reference numerals, and redundant descriptions are omitted. The scale and shape of the illustrated parts are set for convenience in order to simplify the description and are not to be interpreted restrictively unless otherwise specified. The embodiments are illustrative and do not limit the scope of this disclosure in any way. Not all features or combinations thereof presented in the embodiments are necessarily essential to this disclosure. For convenience, embodiments are presented by breaking them down into components for each function and / or group of functions that realize them. However, one component in an embodiment may actually be realized by a combination of multiple components as separate entities, and multiple components in an embodiment may actually be realized by a single component as a whole. Furthermore, multiple embodiments and modifications may be disclosed in parallel, and any components of each embodiment and / or modification may be combined in any manner as long as they do not interfere with each other's functions.

[0015] Figure 1 shows the overall configuration of the unloading machine 1 according to an embodiment of this disclosure. The unloading machine 1 is a continuous unloader or ship-mounted continuous unloader that unloads bulk cargo M loaded onto a ship 200 or as cargo onto land. Hereinafter, the unloading machine 1 will also be referred to as CSU1. The CSU1 continuously transports bulk cargo M stored in the cargo hold 201 of a ship 200 docked at a quay 101 of a pier 102 in a port or the like to land. Examples of typical bulk cargo M include coal, coke, ore, etc.

[0016] The CSU1 is operated by an operator in the main control room 16 located in its main body. The control room for operating the CSU1 may be located elsewhere within the CSU1, or it may be located anywhere on land outside the CSU1.

[0017] The pier 102 where the ship 200 docks constitutes the land area where the bulk cargo M is unloaded, and is constructed of high-strength materials such as reinforced concrete. As shown in the perspective view of Figure 2, the pier 102 is provided with a pair of parallel rails 3 that serve as a track along the longitudinal direction (the direction perpendicular to the plane of the paper in Figure 1) of the ship 200 while it is docked and anchored at the quay 101. The rails 3 constitute a track on which the running section 2, which is the mobile part of the CSU 1, can move or travel. These rails 3 allow the CSU 1 to move relative to the anchored ship 200. As shown in Figure 2, the direction in which the rails 3 are installed is preferably the same as the longitudinal direction of the anchored ship 200 or the quay 101, but it may be any other direction. The rails 3 may also include curved sections and bends. When unloading cargo from the ship 200, the CSU 1 moves along the rails 3 and approaches the hatch 21, which is the upper opening of the cargo hold 201 to be unloaded. Subsequently, the running section 2, the slewing frame 5, the unloading section 9, etc., are driven, and the bulk cargo M is unloaded from the cargo hold 201.

[0018] At the pier 102, a belt conveyor 45 is provided between a pair of rails 3 to transport the unloaded bulk cargo M in a constant direction. As shown in Figure 2, it is preferable that the installation direction of the belt conveyor 45, i.e., the transport direction, coincides with the installation direction of the rails 3, but it may be any other direction. The belt conveyor 45 may also include curved sections and bends. The belt conveyor 45 needs to be provided between the pair of rails 3 where it receives the bulk cargo M unloaded from the CSU 1, but it may be provided outside the pair of rails 3 at other locations.

[0019] The CSU1 comprises a traveling section 2 as a mobile section that can move relative to the ship 200, a slewing frame 5 as a slewing section that can rotate relative to the traveling section 2, and a lifting section 9 provided at the tip of the slewing frame 5 as a cargo handling or lifting device for unloading bulk cargo M. The slewing frame 5 is supported on the traveling section 2 so as to be able to rotate around a slewing axis in the vertical direction (up and down direction in Figure 1). The slewing frame 5 is provided with a boom 7 that extends laterally and intersects the slewing axis, and a bucket elevator, which constitutes the main part of the lifting section 9 as a conveying section, is supported at its tip.

[0020] The lifting section 9 maintains a vertical position regardless of the luffing angle of the boom 7 (the angle of rotation around the luffing axis perpendicular to the plane of the paper in Figure 1) through a parallel link mechanism consisting of the slewing frame 5, boom 7, and parallel link 8. A counterweight 13 is provided at the rear end of the slewing frame 5 opposite to the tip of the boom 7. The counterweight 13 is connected to the tip of the boom 7 via a balancing lever 12. Due to the action of this counterweight 13, the lifting section 9 becomes virtually unloaded, achieving a stable load balance. The main components of the slewing section, such as the slewing frame 5, boom 7, balancing lever 12, and counterweight 13, will collectively be referred to as the main body below.

[0021] A cylinder 15 is provided to adjust the luffing angle of the boom 7. When the cylinder 15 is at its standard length, the luffing angle is 0 degrees, meaning the boom 7 is parallel or horizontal to the ground (left-right direction in Figure 1). Extending the cylinder 15 beyond its standard length causes the tip of the boom 7 to rise, resulting in a positive luffing angle. Reducing the cylinder 15 beyond its standard length causes the tip of the boom 7 to lower, resulting in a negative luffing angle. The lifting section 9, supported at the tip of the boom 7, rises while maintaining a vertical position when the luffing angle of the boom 7 increases, and lowers while maintaining a vertical position when the luffing angle of the boom 7 decreases. In this way, the lifting section 9, as a cargo handling or lifting device, moves up and down integrally with the luffing of the boom 7.

[0022] The main control room 16 for operating the CSU1 is located on the CSU1 or the main body of the slewing unit. In the example shown in Figure 1, the main control room 16 is located on the lifting unit 9 side of the slewing frame 5. The operator in the main control room 16 can safely operate the CSU1 while visually monitoring the lifting unit 9. Alternatively, the operator in the main control room 16 may operate the CSU1 while viewing images or videos of the cargo hold 201 captured by a camera or other imaging device on a monitor. In response to the operation of the CSU1 through the main control room 16, parameters related to the position, posture, and operation of the CSU1 (hereinafter collectively referred to as the CSU state), such as the position of the traveling unit 2, the slewing angle of the slewing frame 5, and the elevation angle of the boom 7, are controlled. Furthermore, the operation of unloading bulk cargo M by the lifting unit 9 can also be operated through the main control room 16.

[0023] The unloading section 9 includes a scraping section 11, which is a cargo handling section for scraping bulk cargo M from within the cargo hold 201, and a bucket elevator, which is a transport section for transporting the bulk cargo M scraped by the scraping section 11 upwards to the outside of the cargo hold 201. The scraping section 11 is located at the bottom of the unloading section 9. A number of buckets 27 (see Figure 3) are provided along the outer circumference of the scraping section 11 so as to be movable in one direction (W in Figure 1), and the bulk cargo M from within the cargo hold 201 is continuously excavated and scraped off. The bulk cargo M scraped off by the scraping section 11 is transported upwards together with the buckets 27 by the bucket elevator.

[0024] Figure 3 shows the detailed configuration of the lifting section 9. The bucket elevator comprises a cylindrical elevator body 14 extending vertically and a chain bucket 29 that rotates along the outer circumference of the elevator body 14 and the scraping section 11. The chain bucket 29 comprises a pair of roller chains 25, each composed of an endless chain, and a plurality of buckets 27 supported on both sides by the pair of roller chains 25. Specifically, the pair of roller chains 25 are arranged side by side in a direction perpendicular to the plane of the paper in Figure 3(B), and each bucket 27 is mounted so as to be suspended between the pair of roller chains 25.

[0025] The bucket elevator includes a drive roller 31a that rotationally drives a stretched roller chain 25, driven rollers 31b and 31c, and a steering roller 33. The drive roller 31a is located at the top 9a of the bucket elevator and is rotationally driven by a motor (not shown) or the like, causing the chain bucket 29 to rotate. The driven roller 31b is located in front of the scraping section 11 (to the left in Figure 3(B)), and the driven roller 31c is located behind the scraping section 11 (to the right in Figure 3(B)), each guiding the rotating chain bucket 29. The steering roller 33 is a driven roller located below the drive roller 31a, which guides the rotating chain bucket 29 and changes its direction of motion. An extendable cylinder 35 is provided between the driven rollers 31b and 31c. When the cylinder 35 extends or retracts, the distance between the axes of the two driven rollers 31b and 31c changes, altering the trajectory of the chain bucket 29's orbital motion. The extension and retraction of the cylinder 35 may be controlled by operation through the main control room 16, or it may be controlled automatically by a computer built into the CSU1 according to a program. In addition, corresponding to the provision of two roller chains 25, two drive rollers 31a, two driven rollers 31b and 31c, and two turning rollers 33 are each provided and arranged side by side in a direction perpendicular to the plane of the paper in Figure 3(B).

[0026] Driven by rotation through the drive roller 31a, the chain bucket 29 revolves along the outer circumference of the elevator body 14 and the scraping section 11. For example, the chain bucket 29 revolves counterclockwise along the arrow W shown in Figure 3(B). During this movement, the chain bucket 29 reciprocates between the scraping section 11 located at the bottom of the bucket elevator and the drive roller 31a located at the top 9a of the bucket elevator.

[0027] Each bucket 27 of the chain bucket 29 rises along the elevator body 14 while maintaining an orientation with its opening facing upward. As each bucket 27 passes the drive roller 31a at the top 9a of the bucket elevator, its direction of motion changes from upward to downward, and the opening of each bucket 27 also rotates from upward to downward. Below the openings of each bucket 27 that have rotated downward in this way, there is a discharge chute (not shown) to which the bulk load M scooped up by each bucket 27 is discharged. The discharge chute discharges the bulk load M onto a rotating feeder 37 (Figure 1) provided on the outer circumference of the upper part of the lifting section 9.

[0028] The rotary feeder 37 rotates around the rotation axis in the extension direction, i.e., the vertical direction, of the elevator body 14, and transfers the bulk load M discharged from the discharge chute to the boom conveyor 39 on the boom 7. The boom conveyor 39 transports the bulk load M along the boom 7 to the vicinity of the rotation axis of the slewing frame 5, and supplies it to a hopper (not shown) located there. An internal conveyor 43 for receiving the bulk load M is provided in the running section 2 below the discharge opening of this hopper. The internal conveyor 43 transfers the bulk load M to the aforementioned belt conveyor 45 located on the pier 102, which is land.

[0029] Next, the basic unloading operation of the CSU1 having the above configuration will be explained. In this unloading operation, the unloading unit 9 and / or CSU1 function as a cargo handling device or unloading device that moves bulk cargo M (ship cargo) from the cargo hold 201 of the ship 200 out of the cargo hold 201.

[0030] The operator of the CSU1 operates the CSU1 from the main control room 16. First, the running section 2 is moved along the rails 3 to a position close to the hatch 21 of the cargo hold 201 to be unloaded. Next, the slewing frame 5 is rotated around a vertical slewing axis located in a position overlapping with the running section 2 in the top view in Figure 1, moving the lifting section 9, located at the tip of the boom 7, above the hatch 21 of the cargo hold 201 to be unloaded. Here, it is preferable that the boom 7 is raised and lowered in the positive direction (clockwise in Figure 1) to prevent the lifting section 9 from colliding with the pier 102 or the ship 200, and that the running and slewing operations are performed when the lifting section 9 is sufficiently raised. Next, the boom 7 is raised and lowered in the negative direction (counterclockwise in Figure 1), and the scraping section 11, located at the tip of the lifting section 9, is inserted into the cargo hold 201 through the hatch 21. Furthermore, the movement of the travel unit 2, the rotation of the slewing frame 5, and the raising and lowering of the boom 7 may be performed simultaneously if there are no safety issues.

[0031] After the scraping section 11 is inserted into the cargo hold 201, the roller chain 25 begins to rotate along the arrow W. The multiple buckets 27 attached to the roller chain 25 excavate and scrape the bulk cargo M stored in the cargo hold 201 as they rotate together with the roller chain 25. The bulk cargo M scraped by each bucket 27 is transported upward along the elevator body 14 as the roller chain 25 rotates.

[0032] The scraping unit 11 may change its three-dimensional position within the cargo hold 201 as appropriate in order to efficiently scrape bulk cargo M from various locations within the cargo hold 201. For example, if the surface position of the bulk cargo M becomes lower as the unloading operation progresses, the boom 7 is raised and lowered in the negative direction, causing the scraping unit 11 to descend. In addition, in order to scrape bulk cargo M near the walls of the cargo hold 201, the position of the scraping unit 11 in the horizontal plane may be changed to move closer to the wall through the operation of the traveling unit 2 and / or the slewing frame 5. The scraping unit 11 may change not only its three-dimensional position but also its posture and shape. For example, the scraping unit 11 is rotatable around the axis of rotation in the extension direction, i.e., the vertical direction, of the elevator body 14, and its orientation can be changed arbitrarily. Also, as shown by the dashed line in Figure 3(B), the scraping unit 11 can take on an inclined shape or a horizontally elongated shape that contracts vertically and extends horizontally. This allows the scraping section 11 to be brought closer to the wall and efficiently scrape off bulk cargo M, even in a cargo hold 201 with a large horizontal distance from the hatch 21 to the wall.

[0033] The control of the CSU state, such as the position, posture, movement, and shape of the scraping section 11 or the lifting section 9 within the cargo hold 201 in relation to the CSU1's unloading operation, may be performed autonomously by the CSU1 using a camera or other imaging device or a distance measuring sensor described later (i.e., the lifting section 9 and / or CSU1 may be operated automatically), or it may be performed manually by an operator in the main control room 16 while communicating with workers in the cargo hold 201.

[0034] As described above, the bucket 27 that has scooped up the bulk cargo M from the cargo hold 201 rises along the elevator body 14, and as it passes the drive roller 31a at its uppermost point 9a, it turns from upward to downward. The bulk cargo M that falls due to the turning of the bucket 27 enters the discharge chute and is discharged onto the rotating feeder 37. Thereafter, the bulk cargo M is transported via the boom conveyor 39 and the in-machine conveyor 43 to the belt conveyor 45 located at the pier 102, which serves as land. This unloading operation is repeated by multiple buckets 27, thereby continuously unloading the bulk cargo M from the cargo hold 201.

[0035] Next, we will describe the distance measuring sensor installed in the CSU1 to improve the safety and efficiency of cargo unloading. The distance measuring sensor constitutes a cargo hold detection unit or position measuring unit that detects the position, orientation, and other conditions of a part of the cargo hold 201, such as the edge of the opening 21, the upper / side surface facing the edge, the ceiling / walls / bottom of the cargo hold 201, and structures inside the cargo hold 201.

[0036] As shown in Figure 1, multiple distance measuring sensors 19 are provided on the upper part of the loading section 9 to measure the distance to objects located below and to the side. In the illustrated example, any object that can be measured by the distance measuring sensors 19 is any object such as the edge of the opening 21, the ceiling / walls / bottom of the cargo hold 201, bulk cargo M and other objects, people / structures inside the cargo hold 201, a bulldozer for bottom dredging, the scraping section 11, the ship 200, other parts of the CSU1 such as the boom 7 / slewing frame 5 / traveling section 2 / main control room 16, the quay 101, the dock 102, the rails 3, the belt conveyor 45, etc. Multiple distance measuring sensors 19 may be arranged, for example, on the upper part of a cylindrical elevator body 14, surrounding the outer circumference of the elevator body 14. Alternatively, multiple distance measuring sensors 19 may be provided on a flange section 91 that rotatably supports the upper part of the elevator body 14, surrounding the outer circumference of the elevator body 14. It is preferable that the multiple distance measuring sensors 19 be positioned below the connection point between the lifting section 9 and the boom 7 so that the boom 7 does not fall within the measurement range below and to the side of the multiple distance measuring sensors 19. On the other hand, if the multiple distance measuring sensors 19 are positioned above the connection point between the lifting section 9 and the boom 7, it is sufficient that each distance measuring sensor 19 is positioned so as not to overlap with the boom 7 when viewed from above (as seen from above in Figure 1). An example of the arrangement of the multiple distance measuring sensors 19 in a top view will be described later. The number of distance measuring sensors 19 is arbitrary. For example, any number of distance measuring sensors 19 that measure distance mainly below the lifting section 9 and any number of distance measuring sensors 19 that measure distance mainly to the side of the lifting section 9 may be provided.

[0037] The scraping section 11 at the bottom of the unloading section 9 is equipped with multiple distance measuring sensors 18 to measure the distance to objects to be measured above, to the side, and below. In the illustrated example, any object can be measured by the distance measuring sensors 18, such as the edge of the opening 21, the ceiling / walls / bottom of the cargo hold 201, bulk cargo M and other objects, people / structures inside the cargo hold 201, a bulldozer for bottom scraping, or other parts of the CSU1 such as the boom 7. The distance measuring sensors 18 are provided at the front (left side in Figure 1) and rear (right side in Figure 1) of the scraping section 11, respectively. To avoid deterioration of measurement accuracy due to dust from the bulk cargo M scraped by the bucket 27 of the scraping section 11, it is preferable that the multiple distance measuring sensors 18 be provided at a location away from the point where the bucket 27 excavates the bulk cargo M (for example, the bottom of the scraping section 11) (for example, the top of the scraping section 11). The number of distance measuring sensors 18 is arbitrary. For example, any number of distance measuring sensors 18 that measure distances mainly to the side of the scraping section 11 and any number of distance measuring sensors 18 that measure distances mainly below the scraping section 11 may be provided.

[0038] Figure 4 shows the external appearance of the distance measuring sensors 18 and 19. The distance measuring sensors 18 and 19 are, for example, distance-measuring laser sensors and constitute a distance measuring unit that measures the distance to an object to be measured. The distance measuring sensors 18 and 19 as laser sensors include a laser light-emitting unit (not shown) that emits laser light toward the object to be measured, including the ship's hold 201, and a laser light-receiving unit (not shown) that receives the laser light reflected by the object to be measured. A translucent portion 171 that allows laser light to pass through is formed in an endless band shape around the entire circumference of the side surface of the cylindrical housing 17 of the distance measuring sensors 18 and 19.

[0039] Multiple laser emitters are provided in the housing 17, facing the translucent portion 171, and emit a linear laser beam to the outside of the housing 17 through the translucent portion 171. Each laser emitter is arranged at a predetermined interval along the direction of the central axis A of the housing 17 (the vertical direction in Figure 4), although Figure 4 simply shows the laser beam being emitted from a single point. Also, as schematically illustrated, there is a difference of about 0.1 to 3 degrees in the emission angle of each laser emitter. Such distance measuring sensors 18 and 19 irradiate laser beam within a predetermined angular range above and below the reference plane S (in the illustrated example, within the range of θ- to θ+), with the plane perpendicular to the central axis A of the housing 17 as the reference plane S. θ- and θ+ can be designed arbitrarily, but in the following example, -θ- = θ+ = 15 degrees. In this case, distance measuring sensors 18 and 19 irradiate laser beam within a range of ±15 degrees centered on the reference plane S. Furthermore, these multiple laser light-emitting units can be rotated 360 degrees integrally around the central axis A of the housing 17. Therefore, the distance measuring sensors 18 and 19 can irradiate laser light onto virtually all objects to be measured around (to the side of) the housing 17. Note that the laser light-emitting units of the distance measuring sensors 18 and 19 may irradiate laser light within any angular range smaller than 360 degrees around the central axis A of the housing 17 (for example, an angular range of 180 degrees or less or an angular range of 120 degrees or less). In addition, it is preferable to use laser light of an invisible wavelength such as near-infrared light so as not to disturb people inside or around the CSU1 or the ship 200.

[0040] The distance measuring sensors 18 and 19 rotate multiple laser light-emitting units together, emitting pulsed laser light at predetermined rotational angles. The pulsed laser light emitted by each laser light-emitting unit is reflected or scattered by the object to be measured and returns to the distance measuring sensors 18 and 19, where it is received by a laser light-receiving unit provided together with each laser light-emitting unit within the housing 17. The calculation unit (not shown) of the distance measuring sensors 18 and 19 calculates the distance to the object to be measured based on the time from when the laser light-emitting unit emits a pulse of laser light until the laser light-receiving unit receives the pulse of laser light reflected from the object to be measured. This technology is also called LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging).

[0041] While laser sensors were given as examples of distance measuring sensors 18 and 19 above, distance measuring sensors 18 and 19 may also use other types of light or electromagnetic waves. For example, a millimeter-wave sensor using so-called millimeter waves with a wavelength of about 1 mm to 10 mm may be used as distance measuring sensors 18 and 19. Millimeter waves have high directivity due to their high frequency of about 30 GHz to 300 GHz, and can be handled in the same way as lasers. A millimeter-wave sensor is configured similarly to the laser sensor in Figure 4, except that a millimeter-wave transmitter (a broad-sense light-emitting unit) that emits millimeter waves toward the object to be measured is provided instead of a laser light-emitting unit, and a millimeter-wave receiver (a broad-sense light-receiving unit) that receives millimeter waves reflected by the object to be measured is provided instead of a laser light-emitting unit. Furthermore, optical sensors that use light other than laser light, such as Time of Flight (ToF) image sensors, may also be used as distance measuring sensors 18 and 19. Moreover, distance measuring sensors 18 and 19 may not have a light-emitting unit that emits light or electromagnetic waves toward the object to be measured. For example, a stereo camera capable of measuring distance by simultaneously photographing the object to be measured from different directions may be used as the distance measuring sensors 18 and 19.

[0042] The distance measuring sensors 18 and 19 shown in Figure 4 can be attached to the CSU shown in Figure 1 at any position and orientation according to the measurement purpose. For example, the distance measuring sensor 18 installed in the scraping section 11 is mounted so that its central axis A in Figure 4 is vertical and its reference plane S is horizontal. This distance measuring sensor 18 can measure the distance within the cargo hold 201, centered on the side of the scraping section 11. Alternatively, the distance measuring sensor 18 may be mounted so that its central axis A in Figure 4 is horizontal and its reference plane S is vertical. This distance measuring sensor 18 can measure the distance to the opening 21 above the scraping section 11 or the bulk load M below the scraping section 11. Note that the orientation of the central axis A of the distance measuring sensor 18 is not limited to the vertical or horizontal direction; it can be any orientation.

[0043] The distance measuring sensor 19, installed on the upper part of the unloading section 9, may be mounted so that its central axis A in Figure 4 is horizontal and its reference plane S is a vertical plane. This distance measuring sensor 19 can measure the distance to the edge of the opening 21 of the cargo hold 201 below, or to bulk cargo M inside the cargo hold 201. Although this distance measuring sensor 19 can also emit laser light upwards, if there is no object to be measured above, the upward measurement may be disabled by covering the upper side of the distance measuring sensor 19 with a light-shielding cover. Alternatively, the distance measuring sensor 19 may be mounted so that its central axis A in Figure 4 is vertical and its reference plane S is parallel to the horizontal plane. This distance measuring sensor 19 can efficiently measure the distance to any object outside the cargo hold 201 located to the side. The orientation of the central axis A of the distance measuring sensor 19 is not limited to the horizontal or vertical direction, but in the following example, it is assumed to be horizontal.

[0044] By installing the distance measuring sensors 18 and 19 described above in the unloading section 9, the position of any object to be measured can be accurately determined, such as the edge of the opening 21, the ceiling / walls / bottom of the cargo hold 201, bulk cargo M and other objects, people / structures inside the cargo hold 201, the bulldozer for bottom dredging, and the scraping section 11. Therefore, collisions between the unloading section 9 and other objects during unloading can be prevented, and bulk cargo M can be unloaded efficiently.

[0045] Figure 5 shows an example of the arrangement of the distance measuring sensors 19 in a top view. Three distance measuring sensors 191, 192, and 193 are arranged to surround the outer circumference of the flange portion 91 or the elevator body 14. Distance measuring sensor 191 is positioned so that its central axis A in Figure 4 is in the left-right direction in Figure 5, and its reference surface S1, corresponding to the reference surface S in Figure 4, is in the up-down direction in Figure 5. Distance measuring sensor 191 measures distance by irradiating laser light within a range of ±15 degrees centered on the reference surface S1. Distance measuring sensors 192 and 193 are positioned so that their central axis A in Figure 4 is in the up-down direction in Figure 5, and their reference surfaces S2 and S3, corresponding to the reference surface S in Figure 4, are in the left-right direction in Figure 5. Distance measuring sensors 192 and 193 measure distance by irradiating laser light within a range of ±15 degrees centered on the reference surfaces S2 and S3. The reference planes S2 and S3 of the distance measuring sensors 192 and 193 are different planes that are parallel to each other and are perpendicular to the reference plane S1 of the distance measuring sensor 191.

[0046] The CSU1 unloads bulk cargo M from the cargo hold 201 using the posture shown in Figure 5 as its basic posture during unloading. In this basic posture, the running section 2 is positioned offset from the front of the cargo hold 201, and the slewing frame 5 and boom 7 are in a slewing position that forms an acute angle with respect to the rails 3 that constitute the track of the running section 2. In this case, the unloading section 9 is located above the cargo hold 201 of the ship 200, and its lower scraping section 11 is inserted into the cargo hold 201 through the opening 21.

[0047] The opening 21 of the cargo hold 201 is often a long rectangle in the direction of the ship 200's movement (left-right direction in Figure 5). In this case, the upper edge E11 and lower edge E12 of the opening 21 can be detected by the distance measuring sensor 191, which irradiates laser light parallel to the short side of the opening 21 (the vertical side in Figure 5). The points shown at the center of edges E11 and E12 represent the positions where the laser light on the reference plane S1 of the distance measuring sensor 191 strikes the edge of the opening 21, and the small rectangle surrounding it schematically represents the range in which the laser light irradiated within a ±15 degree range centered on the reference plane S1 strikes the edge of the opening 21. The same notation is used for distance measuring sensors 192 and 193.

[0048] Similarly, distance measuring sensors 192 and 193, which irradiate laser light parallel to the long side of the opening 21 (the left-right side in Figure 5), can detect the left edge E21, E31 and the right edge E22, E32 of the opening 21. By using the two distance measuring sensors 192 and 193, high-precision distance measurement becomes possible even in the long direction, where distance measurement is more difficult than in the short direction. Thus, the arrangement of distance measuring sensors 191, 192, and 193 in Figure 5 is suitable for detecting the edges of an opening 21 that is long in one direction, such as a rectangle.

[0049] Furthermore, even if the CSU1 is not in the basic position shown in Figure 5, as long as the lifting section 9 is inside the opening 21 when viewed from above, the three distance sensors 191, 192, and 193 can acquire six distance measurement point groups on the edge of the opening 21 corresponding to E11, E12, E21, E22, E31, and E32, allowing the position of the opening 21 to be accurately determined.

[0050] Furthermore, the basic position of the CSU1 during unloading is not limited to that shown in Figure 5. For example, the traveling section 2 may be in front of the cargo hold 201, and the slewing frame 5 and boom 7 may be perpendicular to the rail 3. In this case, since the extension direction of the boom 7 coincides with the short side direction of the opening 21, the reference plane S1 of the distance measuring sensor 191 becomes parallel to the extension direction of the boom 7, and the reference planes S2 and S3 of the distance measuring sensors 192 and 193 become perpendicular to the extension direction of the boom 7. If the distance measuring sensors 191, 192, and 193 are made rotatable integrally around the axis of the cylindrical elevator body 14, then it is easy to arrange the distance measuring sensors 191, 192, and 193 in a manner suitable for the elongated opening 21 as described above, in accordance with changes in the basic position of the CSU1 during unloading.

[0051] The number and / or arrangement of the distance measuring sensors 19 described above is merely an example, and any number and / or arrangement of distance measuring sensors 19 may be used. The number of distance measuring sensors 19 is preferably at least two, and more preferably three or more, in order to efficiently measure the position, orientation, shape, and other conditions of the cargo hold 201 surrounding the unloading section 9 in a top view. Multiple distance measuring sensors 19 may be arranged at equal intervals along the outer circumference of the flange portion 91 or the elevator body 14. In this case, the installation orientation of each distance measuring sensor 19 is arbitrary, but for example, each distance measuring sensor 19 may be installed so that its reference surface S is in contact with the outer circumference of the flange portion 91 or the elevator body 14. With such a symmetrical arrangement, the position, orientation, shape, and other conditions of the cargo hold 201 can be measured stably regardless of the orientation of the CSU 1 during unloading.

[0052] In accordance with the distance measured by the distance measuring sensors 18 and 19 to the cargo hold 201 itself or to objects to be measured inside or outside the cargo hold 201, each movable part of the CSU1, namely the movable traveling part 2, the swivelable swivel frame 5, the luffing boom 7, the rotatable and deformable scraping part 11, etc., is controlled to prevent the unloading part 9 from colliding with the cargo hold 201 itself or other objects (objects to be measured) inside or outside the cargo hold 201 during unloading, and the bulk cargo M is unloaded efficiently. In addition to or instead of the distance measuring sensors 18 and 19, optical sensors such as image sensors or cameras that photograph objects to be measured may be used to detect the cargo hold 201 itself or objects inside or outside the cargo hold 201.

[0053] Figure 6 is a schematic functional block diagram of the distance measuring point cloud adjustment device 300 according to this embodiment, which adjusts the distance measuring point cloud obtained through distance measuring sensors 18 and 19 installed on the CSU1 as a cargo handling machine. The distance measuring point cloud adjustment device 300 comprises a distance measuring point cloud acquisition unit 310, a CSU status acquisition unit 320, a coordinate transformation unit 330, a thinning unit 340, a merged frame generation unit 350, a setting unit 360, and a cargo hold detection unit 370. Some of these functional blocks may be omitted as long as the distance measuring point cloud adjustment device 300 can achieve at least some of the operations and / or effects described below. These functional blocks may be realized by the cooperation of hardware resources such as the central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, and software executed using them. Regardless of the type or location of the computer, each of the above functional blocks may be realized with the hardware resources of a single computer, or with a combination of hardware resources distributed across multiple computers.

[0054] Before describing each functional block of the distance measuring point cloud adjustment device 300, the underlying coordinate system will be explained. Figure 7 schematically shows various coordinate systems that can be set for the CSU1. Figure 7(A) is a schematic diagram of the CSU1 in a vertical plane, including the traveling section 2, the slewing frame 5, the boom 7, and the lifting section 9, and Figure 7(B) is a schematic diagram of the CSU1 in a top view or plan view. Figure 7(A) is a cross-sectional view taken by a plane including the boom 7 that extends diagonally downward and to the left from the slewing frame 5 in Figure 7(B).

[0055] The coordinate system u is a ground coordinate system (or a mobile unit coordinate system based on the ground on which the mobile unit 2 travels) and is the x-axis in the xyz Cartesian coordinate system. x The axis and u as the y-axis y The axis and u as the z-axis z It is determined by the axis. For example, the origin of the ground coordinate system u is set on the track of the running section 2 which is made up of rails 3, u x The direction of the axis coincides with the laying direction of the rail 3, which is the direction of movement of the running section 2, u y The direction of the axis is u in the horizontal planex in a direction orthogonal to the axis, u z The direction of the axis is the vertical direction.

[0056] Here, "the coordinate system u is a ground coordinate system based on the ground" means that the coordinate system u has an arbitrary point on the ground as the origin. For example, the ground coordinate system u may be a coordinate system with an arbitrary position on the quay 102 as the land where the traveling unit 2 is installed as the origin, or a coordinate system with the traveling unit 2 itself traveling on the ground as the origin (a moving unit coordinate system based on the traveling unit 2). In the illustrated example, in the ground coordinate system u, the traveling unit 2 moves only in the u x axis direction, so its u y coordinates and u z coordinates do not change (hereinafter, for simplicity of explanation, it is assumed that the u y coordinates and u z coordinates of the traveling unit 2 are 0). The u x coordinates of the traveling unit 2 can be accurately tracked by a position sensor or the like that measures the position x tl on the rail 3 of the traveling unit 2. Thus, the three-dimensional coordinates of the traveling unit 2 in the ground coordinate system u are (u x , u y , u z ) = (x tl , 0, 0). Note that in the illustrated example, for simplicity of explanation, the direction of the u x axis coincides with the laying direction of the rail 3, but the direction of each axis of the ground coordinate system u can be arbitrarily set.

[0057] The coordinate system r is a turning unit coordinate system based on the turning frame 5, and is defined by the r x axis as the x-axis, the r y axis as the y-axis, and the r z axis as the z-axis in the xyz orthogonal coordinate system. The origin of the turning unit coordinate system r coincides with the turning center O r of the turning frame 5 in the top view of FIG. 7(B), and coincides with a point on the ground directly below the turning center O r in the cross-sectional view of FIG. 7(A). The direction of the r x axis is rotated by a turning angle θ2 with respect to the direction of the u x axis, and r yThe direction of the axis is r in the horizontal plane. x This is the direction perpendicular to the axis (the extension direction of boom 7 in Figure 7(B) in the top view), and r z The axis is oriented vertically.

[0058] In the illustrated example, the pivot center O is visible from above. r Since that coincides with the origin of coordinate system r, x Coordinates and r y The coordinate is 0. Also, the pivot center is O. r r z The coordinates are the height h from the land. r It is constant. Also, the rotation angle θ2 representing the attitude of the rotation frame 5 can be measured by an angle sensor or the like. Thus, the rotation center O of the rotation frame 5 in the rotation coordinate system r r The three-dimensional coordinates are (r x ,r y ,r z )=(0,0,h r ) is expressed as. Note that the slewing section coordinate system r may be a coordinate system whose origin is any position on the main control room 16 which can rotate integrally with the slewing section, such as the slewing frame 5, boom 7, and counterweight 13 that constitute the slewing section. Also, in the illustrated example, for the sake of simplicity of explanation, r y Although the axis direction coincides with the extension direction of boom 7 when viewed from above, the direction of each axis in the slewing coordinate system r can be set arbitrarily.

[0059] Coordinate system b is a luffing coordinate system based on the boom 7 and lifting section 9, and b is the x-axis in the xyz Cartesian coordinate system. x The axis and b as the y-axis y The axis and b as the z-axis z It is determined by the axis. The origin of the luffing coordinate system b is, for example, located at the connection point between the boom 7 and the lifting section 9. Also, b y The axis direction is horizontal and coincides with the extension direction of boom 7 in Figure 7(B) in a top view, b x The direction of the axis is b in the horizontal plane. y It is a direction perpendicular to the axis, b z The axis is oriented vertically.

[0060] In the illustrated example, the boom 7 is at the base end of the luffing center O. b The area is raised by an elevation angle θ1 around it. As shown in Figure 7(A), the origin of coordinate system b and the elevation center O b The distance L b1 Therefore, the relief center O in coordinate system b b coordinates (b x ,b y ,b z ) is (0,-L b1 cosθ1,-L b1 This is expressed as sinθ1). Here, the luffing angle θ1, which represents the attitude of the luffed section, can be measured by an angle sensor or the like. The origin of the luffed section coordinate system b can be any point on the boom 7 that constitutes the luffed section, for example, the luffing center O b The origin of the coordinate system b of the undulating section may also be the origin of the coordinate system b. In this case, the direction of each axis is as shown in the figure, and the coordinates of the connection between the boom 7 and the scraping section 9 are (b x ,b y ,b z ) is (0,L b1 cosθ1,L b1 It is expressed as sinθ(1). Also, in the illustrated example, for the sake of simplicity of explanation, b y Although the axis direction coincides with the extension direction of boom 7 when viewed from above, the direction of each axis in the luffing coordinate system b can be set arbitrarily.

[0061] The coordinate system l is the distance measuring unit coordinate system based on each distance measuring sensor 19, and l is the x-axis in the xyz Cartesian coordinate system. x The axis and l as the y-axis y The axis and l as the z-axis z It is determined by the axis. The origin of the distance measuring unit coordinate system l is, for example, located at the mounting position of each distance measuring sensor 19 to the CSU1 or the lifting unit 9. y The axis direction is horizontal and coincides with the extension direction of boom 7 in Figure 7(B) in the top view, l x The direction of the axis is l in the horizontal plane. y It is a direction perpendicular to the axis, l zThe axis direction is vertical. When multiple distance measuring sensors 19 are provided, as shown in Figure 5 with distance measuring sensors 191 to 193, the distance measuring unit coordinate system l may be common to all distance measuring sensors 19, or the distance measuring unit coordinate system l may be set individually for each distance measuring sensor 19.

[0062] In the example where the installation position of each distance measuring sensor 19 coincides with the origin of the distance measuring unit coordinate system l, the three-dimensional coordinate (l) of each distance measuring sensor 19 is x ,l y ,l z ) is always (0,0,0). Also, the attitude of the rangefinder coordinate system l is (l x axis, l y axis, l z The axis direction represents the orientation of each distance measuring sensor 19. The distance measuring unit coordinate system l may have its origin at any position on the lifting unit 9 where each distance measuring sensor 19 is attached. Also, in the illustrated example, for simplicity of explanation, l is used. y Although the axis direction coincides with the extension direction of the boom 7 when viewed from above, the direction of each axis in the rangefinder coordinate system l can be set arbitrarily.

[0063] The coordinate system d is the distance measuring unit coordinate system based on each distance measuring sensor 18, and d is the x-axis in the xyz Cartesian coordinate system. x The axis and d as the y-axis y The axis and d as the z-axis z It is determined by the axis. The origin of the distance measuring unit coordinate system d is, for example, located at the connection point between the elevator body 14 and the scraping unit 11. Also, d y The direction of the axis is horizontal and coincides with the direction of extension of the scraping portion 11 (not shown) in Figure 7(B) in a top view, d x The direction of the axis is d in the horizontal plane. y It is a direction perpendicular to the axis, d z The axis direction is vertical. As shown in Figure 7(B), d y The direction of the axis is b y axis and r yIt is deviated by a rotation angle θ4 with respect to the axial direction, that is, the extending direction of the boom 7 in the top view. This means that the scraping part 11 has rotated by θ4 around the axis of the elevator main body 14. When a plurality of distance measuring sensors 18 are provided, the coordinate system d of the distance measuring part may be common to the plurality of distance measuring sensors 18, or the coordinate system d of the distance measuring part may be individually set for each distance measuring sensor 18.

[0064] The origin of the coordinate system d of the distance measuring part may be provided at the attachment position of the CSU1 of each distance measuring sensor 18 or to the hoisting part 9. In this case, the three-dimensional coordinates (d x , d y , d z ) of each distance measuring sensor 18 are always (0, 0, 0). Also, the orientation (d x axis, d y axis, d z axis direction) of the coordinate system d of the distance measuring part represents the orientation of each distance measuring sensor 18. In the illustrated example, for simplicity of explanation, the direction of the d z axis coincides with the vertical direction, but the direction of each axis of the coordinate system d of the distance measuring part can be set arbitrarily.

[0065] In FIG. 7(A), the scraping part 11 is schematically shown as a rectangle extending in a direction orthogonal to the axial direction of the elevator main body 14. However, as schematically shown in FIG. 7(C), the scraping part 11 may be constituted by a main part 11A for scraping the bulk cargo M and a bending part 11B that can be bent with respect to the elevator main body 14. Even in such a case, the origin of the coordinate system d of the distance measuring part can be set at an arbitrary position on the scraping part 11, that is, on the main part 11A or the bending part 11B. In the coordinate transformation by the coordinate transformation part 330 described later, the bending angle θ5 of the bending part 11B is also considered.

[0066] The coordinate transformation unit 330, described later, transforms the distance measurement point cloud in the distance measurement unit coordinate system d acquired by the distance measurement sensor 18 and / or the distance measurement point cloud in the distance measurement unit coordinate system l acquired by the distance measurement sensor 19 into coordinates in a reference coordinate system relating to the CSU1. In the following description, "distance measurement unit coordinate system" refers to at least one of the distance measurement unit coordinate system d and the distance measurement unit coordinate system l unless otherwise specified. The reference coordinate system relating to the CSU1 may be any of the aforementioned ground coordinate system u, rotation unit coordinate system r, or elevation unit coordinate system b, or any coordinate system set from the viewpoint of the CSU1, in other words, any coordinate system in which the CSU1 recognizes or tracks the position and orientation (direction of each axis) of the origin. Typically, the CSU1 can handle distance measurement point clouds acquired in different distance measurement unit coordinate systems d and l by multiple distance measurement sensors 18 and 19 in a unified manner (regardless of the position or orientation of each distance measurement sensor 18 and 19) in such a reference coordinate system.

[0067] Next, we will explain each functional block of the distance measuring point cloud adjustment device 300 shown in Figure 6.

[0068] The distance measurement point cloud acquisition unit 310 acquires distance measurement point clouds on the object to be measured over multiple frames at different times (times or time zones) using distance measurement sensors 18 and 19 installed on the CSU1 as a cargo handling machine. Here, the object to be measured can be any object with a steady presence, excluding steam and dust from cargo which are treated as transient noise as described later. In the following example, the cargo hold 201 is used as the object to be measured. However, the object to be measured in this embodiment is arbitrary and may be, for example, the opening 21, structures inside the cargo hold 201, the ship 200, any part of the CSU1 such as the scraping section 11 / boom 7 / slewing frame 5 / traveling section 2 / main control room 16, the quay 101, the dock 102, the rails 3, the belt conveyor 45, etc. One or more distance measurement sensors 18 and 19 acquire distance measurement point clouds on the object to be measured, such as the cargo hold 201, in the distance measurement unit coordinate systems d and l.

[0069] The distance measurement point cloud acquisition unit 310 may acquire a distance measurement point cloud on the object to be measured (ship's hold 201, etc.) over multiple frames at different times, while the relative position and relative orientation of the distance measurement sensors 18, 19 and the object to be measured (ship's hold 201, etc.) remain substantially constant. Alternatively, the distance measurement point cloud acquisition unit 310 may acquire a distance measurement point cloud on the object to be measured while changing at least one of the position and orientation of the distance measurement sensors 18, 19 with respect to the object to be measured using the CSU 1. Specifically, the CSU 1 may change parameters (CSU state) related to the position, orientation, and operation of movable parts such as the traveling unit 2, the slewing frame 5, the boom 7, the lifting unit 9, etc., thereby changing the relative position and / or relative orientation of the distance measurement sensors 18, 19 or the lifting unit 9 with respect to the object to be measured, and the distance measurement point cloud acquisition unit 310 may acquire a distance measurement point cloud on the object to be measured using the CSU 1.

[0070] The CSU state when the distance measurement point cloud acquisition unit 310 acquires each distance measurement point cloud or each frame is acquired by the CSU state acquisition unit 320. The distance measurement point cloud or frame acquired by the distance measurement point cloud acquisition unit 310 and the CSU state acquired by the CSU state acquisition unit 320 are associated with each other based on common time information, etc. The CSU state acquired by the CSU state acquisition unit 320 is the position x of the running unit 2 on the rail 3, as described above with respect to Figure 7. tl Examples include the slewing angle θ2 of the slewing frame 5, the luffing angle θ1 of the boom 7, the rotation angle θ4 of the lifting section 9 or scraping section 11, and the bending angle θ5 of the bending section 11B.

[0071] The coordinate transformation unit 330 transforms the distance measurement point cloud acquired from one or more distance measurement sensors 18, 19 by the distance measurement point cloud acquisition unit 310 into coordinates in a reference coordinate system (e.g., ground coordinate system u) related to the CSU1. Such coordinate transformation between the distance measurement coordinate system and the reference coordinate system can be performed based on the installation data α representing the three-dimensional position and / or three-dimensional orientation of each distance measurement sensor 18, 19 relative to the CSU1 or the load lifting unit 9, and the CSU state at each time obtained by the CSU state acquisition unit 320. For example, if different distance measurement coordinate systems are set for multiple distance measurement sensors 18, 19, the distance measurement point clouds acquired by the distance measurement point cloud acquisition unit 310 will be represented in different distance measurement coordinate systems, but through the coordinate transformation by the coordinate transformation unit 330, the distance measurement point clouds acquired by different distance measurement sensors 18, 19 and / or different distance measurement coordinate systems will be uniformly represented in a reference coordinate system common to the CSU1.

[0072] The distance measurement point cloud or frame converted to the reference coordinate system by the coordinate transformation unit 330 may be displayed on the operation screen of the computer CP used by a user such as the administrator of the CSU1 and / or the distance measurement point cloud adjustment device 300. Figure 8 shows an example of the distance measurement point cloud or frame 400 displayed on such a computer CP operation screen.

[0073] In frame 400, the distance measurement point cluster, transformed into a reference coordinate system (the XYZ coordinate system in Figure 8) by the coordinate transformation unit 330, is displayed in three dimensions. Each distance measurement point constituting frame 400 is a point in the XYZ coordinate system, which is the reference coordinate system. In the illustrated example, the distance measurement point cluster is distributed on the bottom surface B, side wall surface W, edge E, and top surface U of the cargo hold 201, which is the object to be measured. These distance measurement point clusters are typically acquired from multiple distance measurement sensors 18, 19, but may also be acquired from a single distance measurement sensor 18, 19.

[0074] As described above, multiple frames 400 or distance measurement point clouds, as shown in Figure 8, are acquired over different time periods through the distance measurement point cloud acquisition unit 310. Such multiple frames 400 may be acquired over substantially continuous time periods or over intermittent time periods or time zones.

[0075] The thinning unit 340 thins out (i.e., deletes or erases) some of the distance measurement points in each frame 400, as shown in Figure 8. Preferably, the thinning unit 340 thins out some randomly selected distance measurement points in each frame 400. In this case, which distance measurement points are thinned out in each frame 400 is arbitrary or substantially unpredictable.

[0076] The thinning unit 340 preferably thins out a number of distance measurement points equal to the total number of distance measurement points in each frame 400 multiplied by a predetermined thinning rate. Here, the number "1-β" obtained by subtracting the thinning rate β from "1" (representing the survival rate, which is the proportion of distance measurement points remaining after thinning) preferably has a positive correlation with the reciprocal of the number of frames 400 merged by the merged frame generation unit 350, which will be described later. For example, when "N" (a natural number) frames 400 are merged by the merged frame generation unit 350, it is preferable to set the thinning rate β such that the survival rate "1-β" is proportional to its reciprocal "1 / N". Here, if each frame 400 merged by the merged frame generation unit 350 contains the same "M" (natural number) distance measurement points, and the retention rate "1-β" is set to be equal to its reciprocal "1 / N", then the number of distance measurement points included in the merged frame becomes "M*(1-β)*N = M", which is equal to the number of distance measurement points included in each of the original frames 400. In this way, by setting an appropriate decimation rate β, it is possible to effectively prevent the number of distance measurement points included in the merged frame from becoming excessive. The decimation rate β can be set by the setting unit 360, which will be described later.

[0077] The merged frame generation unit 350 generates a merged frame by merging the distance measurement point groups in each frame 400 from which some distance measurement points have been thinned by the thinning unit 340. For example, the merged frame generation unit 350 displays the superimposed distance measurement point groups from "N" frames 400 as a merged frame on the computer CP operation screen as shown in Figure 8. As will be described later, the number of merged frames "N" and the thinning rate β are set by the setting unit 360 so that the number of distance measurement points included in the merged frame does not become excessive, so the merged frame is displayed in the same way as a single frame 400 as shown in Figure 8.

[0078] In this embodiment, as described above, in order to reduce the influence of non-steady distance measurement points caused by steam, dust, etc. from bulk cargo M, or weather or environmental factors such as rain, fog, and sea spray, distance measurement points are thinned out by the thinning unit 340 in each frame 400 acquired by the distance measurement sensors 18 and 19. In the merged frame, which is formed by merging each frame 400 from which some distance measurement points have been thinned out by the merged frame generation unit 350, distance measurement points on steady measurement targets such as the cargo hold 201 become dominant, thus effectively preventing false detections.

[0079] The setting unit 360 sets various parameters related to the processing performed by the decimation unit 340 and / or the merged frame generation unit 350 as described above. For example, the setting unit 360 sets the number of frames "N" that the decimation unit 340 decimates and the merged frame generation unit 350 merges, the time interval (frame interval) between frames that the decimation unit 340 decimates and the merged frame generation unit 350 merges, the aforementioned decimation rate β (or the retention rate "1-β"), etc. As mentioned above, it is preferable that the retention rate "1-β" has a positive correlation with the reciprocal of the number of merged frames "1 / N".

[0080] Furthermore, the frame interval is preferably set to a lengthy time such that the cargo hold 201, as the object to be measured, can be considered to be substantially stationary, and the steam and dust from the bulk cargo M disperse or move (i.e., the coordinates of the distance measurement point in the reference coordinate system change). For example, the frame interval is preferably set between 0.1 seconds and 5 seconds, more preferably between 0.25 seconds and 2.5 seconds, and even more preferably between 0.5 seconds and 1.5 seconds.

[0081] The setting unit 360 may set the above parameters in response to input operations by the user of the computer CP. Alternatively, the setting unit 360 may automatically or autonomously set the above parameters using a processor (not shown) of the computer CP or the distance measuring point cloud adjustment device 300. The parameters set or suggested in this manner may be displayed on the operation screen of the computer CP, and the user of the computer CP may edit them as needed.

[0082] The cargo hold detection unit 370 detects the state of the cargo hold 201 as the object to be measured based on the distance measurement point cloud in the merged frame generated by the merged frame generation unit 350. Examples of the state of the cargo hold 201 include the three-dimensional position (e.g., XYZ coordinates) of a representative point such as the center of gravity or center of the cargo hold 201, and the three-dimensional orientation (e.g., roll angle, pitch angle, yaw angle) of the cargo hold 201. As described above, in the merged frame generated by the merged frame generation unit 350, the influence of non-steady distance measurement points originating from steam, dust, etc. from the bulk cargo M, or weather or environmental factors such as rain, fog, and sea spray is reduced, and steady structural distance measurement points of the cargo hold 201 as the object to be measured are dominant, so the cargo hold 201 can be detected with high accuracy. In other words, cargo hold detection that is robust to noise originating from steam, dust, etc. from the bulk cargo M is realized.

[0083] Furthermore, the detection results of the cargo hold 201 by the cargo hold detection unit 370 may indicate the amount of steam, dust, etc. being generated from the bulk cargo M. For example, if there is a large discrepancy or variation in the distance measurement point cloud in the combined frame or single frame 400 for the cargo hold 201 detected by the cargo hold detection unit 370, it can be inferred that a large amount of steam, dust, etc. is being generated from the bulk cargo M. In such cases, a warning or similar notification may be issued to the user, such as the administrator of the CSU1 and / or the distance measurement point cloud adjustment device 300.

[0084] Figure 9 is a flowchart showing an example of cargo hold detection using the distance measuring point cloud adjustment device 300 according to this embodiment. In the flowchart description, "S" means a step or process.

[0085] In S1, it is determined whether or not to use the noise suppression mode. The noise suppression mode is a mode that performs decimation processing by the decimation unit 340 and frame merging processing by the merged frame generation unit 350 in order to improve robustness against noise. For example, when detecting the initial state (initial position and / or initial attitude) of the cargo hold 201, such as when the CSU1 starts automatic operation, high accuracy is required, so it is preferable to use the noise suppression mode (Yes in S1). On the other hand, after the initial state of the cargo hold 201 has been detected, it is possible to detect the cargo hold 201 with high accuracy using the initial state as a reference, so it is not necessary to use the noise suppression mode (No in S1). Even after the initial state of the cargo hold 201 has been detected, the noise suppression mode may be used intermittently to periodically update the initial state (Yes in S1). Also, even after the initial state of the cargo hold 201 has been detected, the noise suppression mode may be used intermittently on a regular basis (Yes in S1).

[0086] If "Yes" is determined in S1, the process proceeds to S2, where the setting unit 360 performs the noise reduction mode setting. Specifically, as described above, the setting unit 360 sets various parameters related to the processing by the decimation unit 340 and / or the merged frame generation unit 350 (for example, the number of merged frames "N", frame interval, decimation rate β, and remaining rate "1-β").

[0087] In S3, the distance measurement point cloud acquisition unit 310 acquires distance measurement point clouds on the cargo hold 201 over multiple frames at different times using the distance measurement sensors 18 and 19. In S4, the coordinate transformation unit 330 transforms the distance measurement point clouds acquired in S3 from one or more distance measurement sensors 18 and 19 in the distance measurement unit coordinate system into coordinates in the reference coordinate system relating to the CSU1.

[0088] In S5, the thinning unit 340 thins out some of the distance measurement points in each frame 400 obtained through S3 and S4 based on the setting information in S2. In S6, the merged frame generation unit 350 generates a merged frame by merging the distance measurement point groups in each frame 400 from which some distance measurement points were thinned out in S5. In S7, following S6, the cargo hold detection unit 370 detects the initial state of the cargo hold 201 as the object to be measured, based on the distance measurement point group in the merged frame generated in S6. Thus, when the noise reduction mode is used (Yes in S1), the cargo hold detection unit 370 uses the merged frame generated in S6 to detect the initial state of the cargo hold 201, etc., when the CSU1 starts automatic operation, etc.

[0089] If "No" is determined in S1, the process proceeds to S8, where the distance measurement point cloud acquisition unit 310 acquires a distance measurement point cloud on the cargo hold 201 for a single frame in a single time period using the distance measurement sensors 18 and 19. In S9, the coordinate transformation unit 330 transforms the distance measurement point cloud acquired in the distance measurement unit coordinate system in S8 from one or more distance measurement sensors 18 and 19 into coordinates in the reference coordinate system relating to the CSU1.

[0090] In S7, following S9, the cargo hold detection unit 370 detects the state of the cargo hold 201 as the object to be measured based on the distance measurement point cloud in a single frame 400 obtained through S8 and S9. Thus, when the noise suppression mode is not used (No in S1), the cargo hold detection unit 370 detects the state of the cargo hold 201 using a single frame 400 obtained through S8 and S9 after the initial state of the cargo hold 201 is detected in the first S7, etc.

[0091] The present disclosure has been described above based on embodiments. Various modifications are possible for each component and each combination of processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included in the scope of the present disclosure.

[0092] This disclosure is applicable not only to bucket elevator type continuous unloaders described in relation to embodiments, but also to spiral type unloaders and unloaders equipped with air conveying mechanisms.

[0093] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. Hardware resources include, for example, processors, ROMs, RAMs, and various integrated circuits. Software resources include, for example, operating systems and application programs. [Explanation of symbols]

[0094] 1 Cargo lifting machine (CSU), 9 Cargo lifting section, 11 Scraping section, 18 Distance sensor, 19 Distance sensor, 21 Opening, 201 Cargo hold, 300 Distance point cloud adjustment device, 310 Distance point cloud acquisition section, 320 CSU status acquisition section, 330 Coordinate transformation section, 340 Thinning section, 350 Merging frame generation section, 360 Setting section, 370 Cargo hold detection section, 400 Frame.

Claims

1. A distance measurement point cloud acquisition unit that acquires a distance measurement point cloud on an object to be measured over multiple frames at different times, using a distance measurement sensor installed on a loading machine that unloads cargo from a ship's hold, A thinning unit that thins out some of the distance measurement points in each of the aforementioned frames, A merged frame generation unit generates a merged frame in which the groups of distance measurement points in each frame from which some of the distance measurement points have been thinned out are merged, A distance measuring point cloud adjustment device equipped with the following features.

2. The distance measuring point group adjustment device according to claim 1, wherein the thinning unit thins out a number of distance measuring points obtained by multiplying the total number of distance measuring points included in each frame by a predetermined thinning rate.

3. The distance measuring point cloud adjustment device according to claim 2, wherein the number obtained by subtracting the aforementioned thinning rate from "1" is proportional to the reciprocal of the number of frames merged by the merged frame generation unit.

4. The distance measuring point group adjustment device according to claim 1, wherein the thinning unit thins out some distance measuring points randomly selected in each frame.

5. The object to be measured is the ship's hold. The system includes a cargo hold detection unit that detects the state of the cargo hold based on the distance measurement point cloud in the merged frame. A distance measuring point group adjustment device according to any one of claims 1 to 4.

6. The distance measuring point cloud adjustment device according to claim 5, wherein the cargo hold detection unit detects the initial state of the cargo hold using the merged frame.

7. The distance measuring point cloud adjustment device according to claim 6, wherein the cargo hold detection unit detects the initial state of the cargo hold using the merging frame when the unloading machine starts automatic operation.

8. The range measuring point cloud adjustment device according to claim 6, wherein the cargo hold detection unit, after detecting the initial state, detects the state of the cargo hold using a single frame acquired by the range measuring point cloud acquisition unit.

9. By using a distance measuring sensor installed on a cargo handling machine that unloads cargo from a ship's hold, a distance measurement point cloud is acquired on the object being measured over multiple frames at different times, By removing some of the distance measurement points in each of the aforementioned frames, A merged frame is generated by merging the groups of distance measurement points in each frame from which some of the distance measurement points have been thinned out. A method for adjusting distance measurement point clouds.

10. By using a distance measuring sensor installed on a cargo handling machine that unloads cargo from a ship's hold, a distance measurement point cloud is acquired on the object being measured over multiple frames at different times, By removing some of the distance measurement points in each of the aforementioned frames, A merged frame is generated by merging the groups of distance measurement points in each frame from which some of the distance measurement points have been thinned out. A storage medium that stores a distance measurement point cloud adjustment program that causes a computer to execute the program.

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