Sway measurement device

Abstract

To provide a sway measurement device capable of accurately measuring the amount of sway of a structure relative to an object.SOLUTION: A sway measurement device 1 is provided, comprising a base unit 2 to be attached to a structure 100, a rotating unit 3 configured to be rotatably attached to the base unit 2 to be in contact with a target object 200, and a rotation measurement unit 4 for measuring the amount of rotation of the rotating unit 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a motion measurement device. [Background technology]

[0002] At sea, workers may need to leave the ship to access various offshore facilities, such as offshore wind power generation facilities (e.g., floating offshore wind turbines) and seabed mineral drilling platforms, and transfer to the facilities. Patent Document 1 discloses a motion compensation device that measures the amount of motion (displacement) of a ship in the vertical and horizontal directions and suppresses the motion of a table or bridge mechanism installed on the ship relative to the offshore facility based on the measurement data so that workers can safely access the offshore facility from the ship. The motion compensation device of Patent Document 1 uses a laser sensor as a motion measurement device that measures the amount of motion of the ship. Some conventional motion measurement devices also use an acceleration sensor (inertial sensor). These motion measurement devices that use laser sensors or acceleration sensors are all non-contact type measurement devices that do not come into contact with targets such as offshore facilities. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-138722 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with a non-contact type motion quantity measuring device, it is difficult to accurately measure the motion quantity of a structure such as a ship relative to an object such as an offshore facility. For example, when a ship is pressed against an offshore facility, the friction between the two can cause the ship's motion to change irregularly in a short period of time. In such a case, a motion measurement device using an acceleration sensor may not be able to accurately measure the motion amount because measurement errors and processing delays occur due to the calculation of converting the measured acceleration into the motion amount. Furthermore, for example, in a motion measurement device that uses a laser sensor, when the motion of the ship becomes excessively large, the measurement laser beam may deviate from the target, resulting in an inaccurate measurement, and the motion amount may not be measured accurately.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a motion quantity measuring device capable of accurately measuring the motion quantity of a structure relative to an object. [Means for solving the problem]

[0006] A motion measurement device according to one embodiment of the present invention comprises a base unit that is attached to a structure, a rotating unit that is rotatably attached to the base unit and contacts an object, and a rotation measurement unit that measures the number of rotations of the rotating unit. Effect of the Invention

[0007] According to the present invention, the amount of vibration of a structure relative to an object can be accurately measured. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a schematic state in which a motion measurement device according to a first embodiment of the present invention is installed on a ship, which is a structure, and a rotating part is brought into contact with a boat landing bar of an offshore facility, which is an object. [Diagram 2] 2 is a plan view of the motion measurement device of FIG. 1, viewed from a direction perpendicular to the axial direction of a rotating part. [Diagram 3] FIG. 3 is a plan view showing an example of the operation of the motion measurement device of FIGS. 1 and 2. [Figure 4]13 is a plan view of a motion quantity measuring device according to a second embodiment of the present invention, showing a state in which a rotating part is in contact with a boat landing bar. FIG. [Diagram 5] FIG. 11 is a plan view of the motion measurement device according to the third embodiment of the present invention, showing a state in which the clamping of the boat landing bar by the pair of holding members is released. [Figure 6] 6 is a plan view showing a state in which a pair of holding members sandwich a boat landing bar in the motion measuring device of FIG. 5. FIG. [Figure 7] FIG. 13 is a side view showing a schematic state in which a motion measurement device according to a fourth embodiment of the present invention is installed on a ship and a rotating part is brought into contact with a boat landing bar. [Figure 8] FIG. 11 is a plan view of a motion quantity measuring device according to another embodiment of the present invention, showing a state in which a rotating part is in contact with a boat landing bar. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in Fig. 1, a motion quantity measuring device 1 according to the first embodiment is installed on a ship 100, which is a structure, and measures the motion quantity of the ship 100 relative to an offshore facility 200, which is an object. The offshore facility 200 in this embodiment has a boat landing bar 201. The boat landing bar 201 extends in the up-down direction (Z-axis direction). 1 and 2, the motion measurement device 1 includes a base unit 2, a rotation unit 3, and a rotation measurement unit 4. The motion measurement device 1 of this embodiment further includes a pressing mechanism 5, a moving mechanism 6, a turning mechanism 7, and a pair of holding members 8, 8.

[0010] The base part 2 is attached to the ship 100. In Fig. 1, the base part 2 is attached to the bow of the ship 100, but is not limited to this. The base part 2 illustrated in Figs. 1 and 2 is formed in a box shape having an internal cavity and opening in a predetermined direction (the positive direction of the X-axis in Fig. 1).

[0011] The rotating unit 3 is rotatably attached to the base unit 2. Specifically, the rotating unit 3 is supported by a rotation support unit 31 so as to be rotatable about an axis A1. The rotating unit 3 is attached to the base unit 2 via the rotation support unit 31, as well as a cylinder 11 and a rod 12 which constitute a pressing mechanism 5, a moving mechanism 6, and a turning mechanism 7, which will be described later. The rotating part 3 of the present embodiment is formed in a columnar shape whose diameter does not change in the axial direction. Note that the columnar shape also includes a "cylindrical shape."

[0012] The axis A1 of the rotating part 3 is oriented in a direction perpendicular to the direction in which the base part 2 and the rotating part 3 are aligned (the direction in which the base part 2 and the rotating part 3 are arranged). In the motion measurement device 1 provided on the ship 100, the arrangement direction of the base unit 2 and the rotating unit 3 and the axis A1 of the rotating unit 3 are all oriented in a generally horizontal direction (direction perpendicular to the Z-axis direction) when no external force (e.g., waves or wind) acts on the ship 100 floating on the sea. As illustrated in Figs. 1 and 2, when the motion measurement device 1 is attached to the bow (or stern) of the ship, the axis A1 of the rotating unit 3 is oriented in the left-right direction (Y-axis direction) of the ship 100 when the arrangement direction of the base unit 2 and the rotating unit 3 coincides with the fore-aft direction (X-axis direction) of the ship 100. When the motion measurement device 1 is attached to the side (end in the left-right direction) of the ship 100, the axis A1 of the rotating unit 3 is oriented in the fore-aft direction (X-axis direction) of the ship 100 when the arrangement direction of the base unit 2 and the rotating unit 3 coincides with the left-aft direction (Y-axis direction) of the ship 100.

[0013] The rotating unit 3 comes into contact with the target object, the floating facility 200. While in contact with the floating facility 200, the rotating unit 3 can rotate relative to the base unit 2 so as to roll on the surface of the floating facility 200. Specifically, the rotating unit 3 comes into contact with a boat landing bar 201 of the floating facility 200, and rotates so as to roll up and down on the side surface of the boat landing bar 201.

[0014] The rotation measurement unit 4 measures the number of rotations of the rotating unit 3. The number of rotations measured by the rotation measurement unit 4 is not limited to integer units, but may be measured in any angle unit equal to or less than one rotation. In other words, it can be said that the rotation measurement unit 4 measures the rotation angle of the rotating unit 3. The rotation measurement unit 4 may be, for example, a rotary encoder. By providing the rotation measurement unit 4 to the motion amount measuring device 1, it is possible to measure the amount of motion of the ship 100 in the direction in which the rotating unit 3 rolls on the surface of the offshore facility 200 (specifically, the up-down direction). 2, the rotation measurement unit 4 is positioned adjacent to the rotating unit 3 in the axial direction, but this is not limited thereto. The rotation measurement unit 4 may be disposed, for example, inside the rotating unit 3. In this case, the rotation measurement unit 4 can be protected.

[0015] The pressing mechanism 5 is provided between the base unit 2 and the rotating unit 3, and presses the rotating unit 3 away from the base unit 2, thereby pressing the rotating unit 3 against the offshore facility 200. The pressing mechanism 5 of the present embodiment includes a cylinder 11, a rod 12, and an elastic unit 13.

[0016] The cylinder 11 is formed in a cylindrical shape extending in the arrangement direction of the base part 2 and the rotating part 3. The rod 12 is attached to the cylinder 11 so as to be movable in the same arrangement direction. Specifically, the rod 12 is formed in a bar shape extending in the same arrangement direction. The rod 12 is movable in the arrangement direction relative to the cylinder 11 by inserting at least a portion thereof into the cylinder 11. The elastic part 13 is provided between the cylinder 11 and the rod 12 in the arrangement direction. The elastic part 13 is elastically deformed by the relative movement of the cylinder 11 and the rod 12. The elastic part 13 may be, for example, a spring or rubber.

[0017] The pressing mechanism 5 may be, for example, a hydraulic cylinder or an air cylinder including a cylinder 11 and a rod 12. In these cases, the elastic part 13 is not limited to a spring or rubber, and may be, for example, a fluid such as oil or air filled in the cylinder 11.

[0018] 1, the cylinder 11 is attached to the base portion 2, and the rod 12 is attached to the rotating portion 3. For example, the cylinder 11 may be attached to the rotating portion 3, and the rod 12 may be attached to the base portion 2. In the motion measurement device 1 including the pressing mechanism 5 configured as above, when the base part 2 is moved closer to the offshore facility 200 while the rotating part 3 is in contact with the offshore facility 200, the elastic part 13 of the pressing mechanism 5 is elastically compressed. As a result, the rotating part 3 is pressed against the offshore facility 200 by the elastic force of the elastic part 13.

[0019] Although not shown, the motion amount measuring device 1 of this embodiment further includes a movement amount measuring unit that measures the amount of movement of the rotating unit 3 relative to the base unit 2 in the arrangement direction of the base unit 2 and the rotating unit 3 when the rotating unit 3 is pressed against the offshore facility 200 (target object) by the above-mentioned pressing mechanism 5. The movement amount measuring unit may be, for example, a linear encoder that measures the movement length of the rod 12 relative to the cylinder 11. By including the movement amount measuring unit in the motion amount measuring device 1, it is possible to measure the amount of movement of the ship 100 relative to the offshore facility 200 in a direction in which the ship 100 approaches or moves away from the offshore facility 200 (for example, the X-axis direction in FIG. 1).

[0020] The moving mechanism 6 is provided between the base unit 2 and the rotating unit 3, and moves the rotating unit 3 between a storage position P11 close to the base unit 2 and a use position P12 away from the base unit 2. In Fig. 1, the storage position P11 of the rotating unit 3 is a position where the rotating unit 3 is located above the ship 100 and does not protrude outside the ship 100 in the horizontal direction. On the other hand, the use position P12 of the rotating unit 3 is a position where the rotating unit 3 protrudes outside the ship 100 in the horizontal direction.

[0021] The moving mechanism 6 of this embodiment includes a cylinder 11 and a rod 12 which also constitute the above-mentioned pressing mechanism 5, and a driving unit (not shown). The driving unit drives the rod 12 in the arrangement direction of the base unit 2 and the rotating unit 3 relative to the cylinder 11. The driving unit may be, for example, an actuator. The movement mechanism 6 may be, for example, a hydraulic cylinder or an air cylinder including a cylinder 11 and a rod 12. In these cases, the drive unit may be, for example, a fluid such as oil or air filled in the cylinder 11, and the rod 12 can be moved relative to the cylinder 11 by increasing or decreasing the fluid filled in the cylinder 11.

[0022] The turning mechanism 7 is provided between the base part 2 and the rotating part 3, and turns the rotating part 3 relative to the base part 2. The turning mechanism 7 of this embodiment includes a rod-shaped part 10 and a rotating shaft 20 (hereinafter referred to as the turning rotating shaft 20). The rod-shaped portion 10 extends in the arrangement direction of the base portion 2 and the rotating portion 3. A first end in the longitudinal direction of the rod-shaped portion 10 is connected to the base portion 2, and a second end in the longitudinal direction of the rod-shaped portion 10 is connected to the rotating portion 3. The rod-shaped portion 10 in this embodiment is composed of a cylinder 11 and a rod 12 which also constitute the pressing mechanism 5 and the moving mechanism 6 described above.

[0023] The rotating shaft 20 for turning is provided at a first end of the rod-shaped portion 10, and connects the rod-shaped portion 10 to the base portion 2 so as to be freely rotatable. This allows the rod-shaped portion 10 and the rotating portion 3 to turn around the axis A2 of the rotating shaft 20 with respect to the base portion 2. In this embodiment, the axis A2 of the rotating shaft 20 for turning is perpendicular to the arrangement direction (the longitudinal direction of the rod-shaped portion 10) and the axis A1 of the rotating portion 3. The axis A2 of the rotating shaft 20 for turning faces generally in the up-down direction when no external force (e.g., waves or wind) acts on the ship 100 floating on the sea. Therefore, the rod-shaped portion 10 and the rotating portion 3 turn so as to sway generally in the left-right direction with respect to the base portion 2, based on the state in which the longitudinal direction of the rod-shaped portion 10 faces the front-rear direction (see Figs. 2 and 3).

[0024] Although not shown, the motion amount measuring device 1 of this embodiment further includes a rotation angle measuring unit that measures the rotation angle of the rotating unit 3 relative to the base unit 2 when the rotating unit 3 is in contact with the offshore facility 200 (target object). The rotation angle measuring unit of this embodiment measures the rotation angle of the rod-shaped unit 10 relative to the base unit 2. The rotation angle measuring unit may be, for example, a rotary encoder. By including the rotation angle measuring unit in the motion amount measuring device 1, it is possible to measure the amount of movement of the ship 100 relative to the offshore facility 200 in the left-right direction (Y-axis direction).

[0025] 2, a pair of holding members 8, 8 are provided at both axial ends of the rotating unit 3, and the offshore facility 200 is disposed therebetween with at least the rotating unit 3 in contact with the offshore facility 200. What can be disposed between the pair of holding members 8, 8 is, for example, a rod-shaped object (rod-shaped object) extending in one direction, such as a boat landing bar 201 of the offshore facility 200. The pair of holding members 8, 8 extend from both ends of the axial direction of the rotating unit 3 so as to move away from the rotating unit 3 in the radial direction. The pair of holding members 8, 8 also extend from both ends of the axial direction of the rotating unit 3 in a direction away from the base unit 2 in the arrangement direction of the base unit 2 and the rotating unit 3 (positive direction of the X-axis in FIG. 2), that is, in the opposite direction to the rod 12 with respect to the rotating unit 3. The pair of holding members 8, 8 are positioned with a gap in between in the axial direction of the rotating unit 3. In this embodiment, the portions of the pair of holding members 8, 8 facing each other are parallel to each other. In FIG. 2, the pair of holding members 8, 8 are each formed in a rod shape, but this is not limited thereto.

[0026] In a state in which the boat landing bar 201 is disposed between the pair of holding members 8, 8, the pair of holding members 8, 8 restrict the boat landing bar 201 from moving in its axial direction relative to the rotating part 3. In other words, it is possible to prevent the boat landing bar 201 from shifting in its axial direction relative to the rotating part 3. In addition, in a state where the boat landing bar 201 is disposed between the pair of holding members 8, 8, the pair of holding members 8, 8 allow the movement of the boat landing bar 201 in a direction perpendicular to the axial direction of the rotating part 3 (for example, the up-down direction). In other words, even if the boat landing bar 201 is disposed between the pair of holding members 8, 8, the rotating part 3 is allowed to roll on the boat landing bar 201 in the up-down direction.

[0027] As described above, the motion amount measuring device 1 of this embodiment includes the rotating unit 3 rotatably attached to the base unit 2 attached to the ship 100 (structure) and in contact with the boat landing bar 201 (object), and the rotation measuring unit 4 that measures the number of rotations of the rotating unit 3. Therefore, the rotating unit 3 can rotate as if rolling on the side surface of the boat landing bar 201 while in contact with the side surface (surface) of the boat landing bar 201. Then, by the rotating unit 3 rolling on the side surface of the boat landing bar 201, the motion amount of the ship 100 in the direction in which the rotating unit 3 rolls can be accurately measured based on the measurement result by the rotation measuring unit 4. For example, when the rotating unit 3 rolls in the up-down direction relative to the boat landing bar 201, the motion amount of the ship 100 in the up-down direction can be measured.

[0028] Furthermore, in the motion amount measuring device 1 of this embodiment, the rotating part 3 is cylindrical with a diameter that does not change in the axial direction. Therefore, even if the contact position of the rotating part 3 with the boat landing bar 201 (target object) shifts in the axial direction of the rotating part 3, the relationship between the length that the rotating part 3 rolls on the side surface of the boat landing bar 201 and the number of rotations of the rotating part 3 does not change. Therefore, the motion amount of the ship 100 relative to the boat landing bar 201 (offshore facility 200) can be accurately measured.

[0029] The motion amount measuring device 1 of this embodiment also includes a pressing mechanism 5 that is provided between the base unit 2 and the rotating unit 3 and presses the rotating unit 3 against the boat landing bar 201 (target object). Therefore, by pressing the rotating unit 3 against the boat landing bar 201 by the pressing mechanism 5, the rotating unit 3 can be brought into stable contact with the boat landing bar 201 even if the ship 100 approaches or moves away from the boat landing bar 201. Therefore, the motion amount of the ship 100 relative to the boat landing bar 201 can be reliably measured.

[0030] In addition, the motion measurement device 1 of this embodiment is provided with a moving mechanism 6 that is provided between the base unit 2 and the rotating unit 3 and moves the rotating unit 3 between a storage position P11 close to the base unit 2 and a usage position P12 away from the base unit 2. Therefore, by disposing the rotating part 3 at the use position P12 away from the base part 2 by the moving mechanism 6, the rotating part 3 can be positioned away from the ship 100 (structure), for example, the rotating part 3 can be disposed at a position that protrudes outward from the ship 100 in the horizontal direction. This allows the rotating part 3 to be reliably brought into contact with the boat landing bar 201 (target object) and the amount of rocking of the ship 100 relative to the boat landing bar 201 to be measured. On the other hand, by using the movement mechanism 6 to place the rotating part 3 in the storage position P11 close to the base part 2, the rotating part 3 can be placed close to or inside the ship 100. For example, the rotating part 3 can be positioned above the ship 100 without protruding outside the ship 100 in the horizontal direction. This allows the motion amount measuring device 1 to be stored compactly when not in use and not measuring the motion amount.

[0031] Furthermore, the motion quantity measuring device 1 of this embodiment includes a turning mechanism 7 that is provided between the base unit 2 and the rotating unit 3 and turns the rotating unit 3 relative to the base unit 2. Therefore, even if the ship 100 (structure) moves relative to the boat landing bar 201 (target object), the rotating unit 3 can be maintained facing the boat landing bar 201 (target object) by turning relative to the base unit 2 (see FIGS. 2 and 3). In other words, the rotating unit 3 can be made to follow the boat landing bar 201. In addition, in the case where the motion amount measuring device 1 is equipped with a rotation mechanism 7, although not shown, for example, even if the surface of the object with which the rotating part 3 comes into contact is flat (flat), the rotating part 3 can be made to suitably follow the flat surface of the object, thereby effectively preventing the rotating part 3 from moving away from the flat surface.

[0032] The motion measurement device 1 of this embodiment also includes a pair of holding members 8, 8 provided on both axial ends of the rotating unit 3. When the rotating unit 3 is in contact with the boat landing bar 201 (target object), the boat landing bar 201 is disposed between the pair of holding members 8, 8. Therefore, when the rotating unit 3 is in contact with the boat landing bar 201, it is possible to prevent the boat landing bar 201 from shifting in the axial direction of the rotating unit 3 relative to the rotating unit 3 and separating from the rotating unit 3.

[0033] Furthermore, since the motion measurement device 1 of this embodiment includes the rotating mechanism 7 in addition to the pair of holding members 8,8, the pair of holding members 8 can be protected. This point will be described below. For example, when the boat landing bar 201 located between the pair of holding members 8,8 shifts in the axial direction of the rotating unit 3, the boat landing bar 201 is pressed against one of the holding members 8. At this time, the rod-shaped unit 10, the rotating unit fixed thereto, and the pair of holding members 8,8 rotate relative to the base unit 2 so that the pressing force of the boat landing bar 201 against the one of the holding members 8 is weakened. This makes it possible to protect the one of the holding members 8.

[0034] Furthermore, in the motion amount measuring device 1 of this embodiment, while the rotating part 3 is pressed against the offshore facility 200 (target object) by the pressing mechanism 5, the movement amount measuring unit measures the relative movement amount of the components of the pressing mechanism 5 (cylinder 11 and rod 12). This makes it possible to accurately measure the movement amount of the rotating part 3 relative to the base part 2 in the arrangement direction of the base part 2 and the rotating part 3. Therefore, it is possible to accurately measure the movement amount of the ship 100 relative to the offshore facility 200 in the direction in which the ship 100 (structure) approaches or moves away from the offshore facility 200 (target object).

[0035] Furthermore, in the motion amount measuring device 1 of this embodiment, on the premise that the rotating part 3 can be rotated relative to the base part 2 by the rotation mechanism 7, the rotation angle measuring part measures the rotation angle of the rotating part 3 relative to the base part 2 while the rotating part 3 is in contact with the offshore facility 200 (target object). This makes it possible to accurately measure the amount of motion of the ship 100 relative to the offshore facility 200 in the rotation direction of the rotating part 3 relative to the base part 2.

[0036] As described above, the motion measurement device 1 of this embodiment includes a rotation measurement unit 4 that measures the amount of movement of the ship 100 generally in the up-down direction when the rotation unit 3 is in contact with the offshore facility 200 (target object), and a motion sensor that measures the amount of movement of the ship 100 generally in the fore-aft direction. The instrument is provided with a rotation amount measuring unit that measures the amount of movement of the ship 100 generally in the left-right direction, and a turning angle measuring unit that measures the amount of three-dimensional oscillation of the ship 100 relative to the offshore facility 200.

[0037] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 4. In the following description, configurations common to those already described will be given the same reference numerals and duplicated description will be omitted.

[0038] 4, the motion quantity measuring device 1B of the second embodiment, like the first embodiment, includes a pair of holding members 8, 8 provided at both ends in the axial direction of the rotating part 3 and disposing the boat landing bar 201 (target object) of the offshore facility 200 therebetween with at least the rotating part 3 in contact with the boat landing bar 201. The pair of holding members 8, 8 extend from both ends in the axial direction of the rotating part 3 in a direction away from the base part 2 in the arrangement direction of the base part 2 and the rotating part 3. However, in the second embodiment, the portions of the pair of holding members 8, 8 facing each other are inclined with respect to the axis A1 of the rotating part 3 so as to move away from each other in the axial direction of the rotating part 3 as they move away from the rotating part 3 in the radial direction of the rotating part 3. That is, the pair of holding members 8, 8 have guide inclined portions 81 that are inclined so as to move away from each other in the axial direction of the rotating part 3 as they move away from the rotating part 3 in the radial direction of the rotating part 3. Note that, for example, only one holding member 8 of the pair of holding members 8, 8 may have the guide inclined portion 81, and the other holding member 8 may not have the guide inclined portion 81. That is, the other holding member 8 may be perpendicular to the axis A1 of the rotating part 3.

[0039] According to the motion amount measuring device 1B of the second embodiment, the same effects as those of the first embodiment are achieved. Moreover, in the motion amount measuring device 1B of the second embodiment, at least one of the holding members 8 has an inclined guide portion 81 that inclines so as to move away from the other holding member 8 in the axial direction as it moves away from the rotating unit 3 in the radial direction of the rotating unit 3. This inclined guide portion 81 makes it possible to guide the boat landing bar 201 (object) between the pair of holding members 8, 8. This makes it possible to easily bring the rotating unit 3 into contact with the boat landing bar 201.

[0040] Third Embodiment Next, a third embodiment of the present invention will be described with reference to Figures 5 and 6. In the following description, components common to those already described will be given the same reference numerals and duplicated description will be omitted.

[0041] As shown in Figures 5 and 6, the motion measurement device 1C of the third embodiment, like the first embodiment, is provided with a pair of retaining members 8, 8 at both axial ends of the rotating part 3 and positions the boat landing bar 201 therebetween with at least the rotating part 3 in contact with the boat landing bar 201 (target object) of the offshore facility 200.

[0042] The motion measuring device 1 of the third embodiment further includes a clamping unit 9 that changes the distance between the pair of holding members 8,8. As shown in Fig. 6, the clamping unit 9 narrows the gap between the pair of holding members 8, 8 as the boat landing bar 201 comes into contact with the rotating unit 3, and the object is clamped between the pair of holding members 8, 8. As shown in Fig. 5, the clamping unit 9 widens the gap between the pair of holding members 8, 8 as the boat landing bar 201 moves away from the rotating unit 3, and releases the clamping of the boat landing bar 201 by the pair of holding members 8, 8. That is, the pair of holding members 8, 8 are movable between a release position P22 where the boat landing bar 201 is not clamped, and a clamping position P21 where the boat landing bar 201 is clamped.

[0043] The clamping unit 9 shown in FIGS. 5 and 6 includes a rotating portion 3, a pair of holding members 8, 8, and a link mechanism 90. The rotating part 3 is attached to the rod-shaped part 10 (rod 12) so as to be movable in the arrangement direction of the base part 2 and the rotating part 3. Although not shown in Figs. 5 and 6, the rotating part 3 is attached to the rod-shaped part 10 so as to be movable together with a rotation support part 31 (see Fig. 2 etc.) that rotatably supports the rotating part 3. In addition, the rotating part 3 is elastically pressed by a pressing part (not shown) so as to move away from the base part 2 relative to the rod-shaped part 10 in the arrangement direction. The pressing part may be composed of an elastic body such as a spring or rubber.

[0044] The pair of holding members 8, 8 are each rotatable about a rotation shaft 82 (hereinafter referred to as the clamping rotation shaft 82) located at both ends of the axial direction of the rotating part 3. The axis of the clamping rotation shaft 82, which is the rotation center of each holding member 8, extends in a direction perpendicular to the arrangement direction and the axial direction of the rotating part 3 (the Z-axis direction in Figs. 5 and 6). The pair of holding members 8, 8 and the clamping rotation shaft 82 are provided on the rod-shaped part 10 side. For this reason, the aforementioned rotating part 3 is also movable in the arrangement direction relative to the pair of holding members 8, 8.

[0045] 5, when the pair of holding members 8, 8 are arranged at the release position P22, similarly to the second embodiment, they are inclined with respect to the axis A1 of the rotating part 3 so as to move away from each other in the axial direction of the rotating part 3 as they move away from the rotating part 3 in the radial direction of the rotating part 3. As a result, when the pair of holding members 8, 8 are arranged at the release position P22, the boat landing bar 201 can be guided between the pair of holding members 8, 8. The pair of holding members 8, 8 rotate about the clamping rotation shaft 82 and approach each other in the axial direction of the rotating part 3, thereby moving from the release position P22 shown in Fig. 5 to the clamping position P21 shown in Fig. 6. This allows the boat landing bar 201 to be clamped by the pair of holding members 8, 8 arranged at the clamping position P21.

[0046] The link mechanism 90 transmits the force with which the rotating unit 3 is pressed by the boat landing bar 201 to the pair of holding members 8,8, and converts the force into a force that rotates the pair of holding members 8,8 so that the distance between the pair of holding members 8,8 becomes narrower. The link mechanism 90 includes a fixed arm 91 and two link arms 92. The fixed arm 91 extends from the rotating unit 3. The two link arms 92 are rotatably attached to the tip of the fixed arm 91. The two link arms 92 connect the tip of the fixed arm 91 and the pair of holding members 8,8. Each link arm 92 is attached to the holding member 8 at a position away from the clamping rotation shaft 82.

[0047] In the clamping unit 9 described above, when the boat landing bar 201 is pressed against the rotating part 3, the pair of holding members 8, 8 clamp the boat landing bar 201. Specifically, as shown in FIG. 5, when the boat landing bar 201 is pressed against the rotating part 3 with the pair of holding members 8, 8 disposed at the release position P22, the rotating part 3 moves toward the rod-shaped part 10 against the elastic force of the pressing part. As the rotating part 3 moves, the two link arms 92 each rotate with respect to the fixed arm 91. The rotation of these two link arms 92 is transmitted to the pair of holding members 8, 8, and the pair of holding members 8, 8 each rotate from the release position P22 toward the clamping position P21. As a result, the pair of holding members 8, 8 clamp the boat landing bar 201, as shown in FIG. 6.

[0048] On the other hand, when the boat landing bar 201 is separated from the rotating unit 3, the rotating unit 3 is returned to the initial position shown in Fig. 5 by the elastic force of the pushing unit. The movement of the rotating unit 3 is transmitted to the pair of holding members 8, 8 via the link mechanism 90, and the pair of holding members 8, 8 each rotate from the clamping position P21 toward the release position P22. As a result, the clamping of the boat landing bar 201 by the pair of holding members 8, 8 is released, as shown in Fig. 5.

[0049] The motion amount measuring device 1C of the third embodiment provides the same effects as those of the first and second embodiments. Furthermore, in the motion amount measuring device 1C of the third embodiment, when the rotating part 3 is in contact with the boat landing bar 201 (target object), the pair of holding members 8, 8 clamp the boat landing bar 201. This makes it possible to reliably prevent the boat landing bar 201 from shifting in the axial direction with respect to the rotating part 3 when the boat landing bar 201 is in contact with the rotating part 3. Furthermore, in the motion measurement device 1C of the third embodiment, when the rotating unit 3 is separated from the boat landing bar 201, the sandwiching of the object by the pair of holding members 8, 8 is released, and the gap between the pair of holding members 8, 8 is widened. This makes it easier to insert the boat landing bar 201 between the pair of holding members 8, 8.

[0050] In the third embodiment, the clamping unit 9 is not limited to being configured using the link mechanism 90, and may be configured, for example, by a contact sensor and an actuator. The contact sensor detects whether the boat landing bar 201 (object) is in contact with the rotating unit 3. The actuator drives at least one of the pair of holding members 8, 8 in a direction to bring the pair of holding members 8, 8 closer to each other and in a direction to move the pair of holding members 8, 8 away from each other. When the contact sensor detects that the boat landing bar 201 has come into contact with the rotating unit 3, the actuator moves the pair of holding members 8, 8 in a direction to bring the pair of holding members 8, 8 closer to each other. Also, when the contact sensor detects that the boat landing bar 201 has moved away from the rotating unit 3, the actuator moves the pair of holding members 8, 8 in a direction to move the pair of holding members 8, 8 away from each other.

[0051] Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to Fig. 7. In the following description, configurations common to those already described will be given the same reference numerals and duplicated description will be omitted.

[0052] As shown in Fig. 7, the motion quantity measuring device 1D of the fourth embodiment further includes a scraper 40 in addition to the same configuration as the motion quantity measuring device 1 of the first embodiment. The scraper 40 is disposed at a position adjacent to the rotating part 3 in the radial direction of the rotating part 3. The scraper 40 scrapes the surface of the boat landing bar 201 at least when the boat landing bar 201 (target object) is in contact with the rotating part 3. Note that the scraper 40 may scrape the surface of the boat landing bar 201 even when the boat landing bar 201 is not in contact with the rotating part 3, for example.

[0053] The scraper 40 illustrated in FIG. 7 is formed in a plate shape that is elastically deformable. The scraper 40 is formed in a plate shape that is thinner as it approaches the boat landing bar 201. The scraper 40 may be formed in a thin plate shape with a constant thickness, for example. It is preferable that the scraper 40 does not damage the boat landing bar 201 or is unlikely to damage the boat landing bar 201 even when it scrapes the surface of the boat landing bar 201. The scraper 40 may be made of rubber, for example.

[0054] 7, the scrapers 40 are located on both sides of the rotating part 3 in the direction in which the rotating part 3 rolls on the side surface of the boat landing bar 201 (the up-down direction). Note that the scrapers 40 may be located, for example, on only one side of the rotating part 3 in the up-down direction. In addition, the scrapers 40 are attached to the bar-shaped part 10 (rod 12) in FIG. 7, but they may be attached to the rotation support part 31 or the base part 2, for example.

[0055] The motion amount measuring device 1D of the fourth embodiment provides the same effects as the first embodiment. Moreover, the motion amount measuring device 1D of the fourth embodiment includes a scraper 40 that scrapes the surface of the boat landing bar 201 (target object) while the boat landing bar 201 is in contact with the rotating unit 3. Therefore, foreign matter (e.g., marine organisms, dirt, water, etc.) attached to the side surface of the boat landing bar 201 that may come into contact with the rotating unit 3 can be removed from the surface of the boat landing bar 201 by the scraper 40. This makes it possible to suppress or prevent the rotating unit 3 from being damaged by foreign matter. Also, by preventing the rotating unit 3 from slipping on the surface of the target object due to foreign matter, it is possible to suppress or prevent errors from occurring in the measured motion amount.

[0056] The scraper 40 shown in the fourth embodiment may be applied to, for example, the motion amount measuring device 1 of the second or third embodiment.

[0057] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0058] In the present invention, for example, as shown in FIG. 8, the rotating shaft 20 for turning constituting the turning mechanism 7 may be provided at the second end of the rod-shaped portion 10 located on the rotating portion 3 side. In this case, the rotating portion 3 is connected to the rod-shaped portion 10 so as to be rotatable. Note that in FIG. 8, the first end (cylinder 11) of the rod-shaped portion 10 is fixed to the base portion 2 so as not to rotate, but it may be attached to the base portion 2 so as to be rotatable, as in the above embodiment. That is, the rotating shaft 20 for turning may be provided at both ends (first end, second end) of the rod-shaped portion 10, for example. Even with such a configuration, the same effects as those of the above embodiment can be achieved.

[0059] In the present invention, the turning mechanism 7 may not have, for example, the rod-shaped portion 10, and may be configured only by the turning shaft 20. In other words, the turning mechanism 7 may be, for example, the turning shaft 20 that rotatably attaches the rotation support portion 31 to the base portion 2.

[0060] In the present invention, the pressing mechanism 5 is not limited to a configuration that utilizes the elastic force of the elastic portion 13, and may be a configuration that utilizes, for example, the driving force of an actuator. That is, the pressing mechanism 5 may include, for example, an actuator that moves the rotating portion 3 in a direction away from the base portion 2. In this case, the pressing mechanism 5 may further include a contact sensor that detects whether or not an object has come into contact with the rotating portion 3. In this way, when the contact sensor detects that the object has come into contact with the rotating portion 3, the rotating portion 3 can be pressed against the object by the driving force of the actuator.

[0061] In the present invention, the structure for moving the rotating part 3 relative to the base part 2 in the arrangement direction is not limited to the cylinder 11 and the rod 12. The structure for moving the rotating part 3 relative to the base part 2 may be, for example, two guide rails that are relatively movable in one direction. In this case, one guide rail may be attached to the base part 2, and the other guide rail may be attached to the rotating part 3.

[0062] In the present invention, the rotating part 3 may be attached to the base part 2, for example, via only the rotation support part 31. The base part 2 may also be provided integrally with a structure such as a ship 100. In other words, the rotating part 3 may be attached to the structure so as to be rotatable around the axis A1.

[0063] In the present invention, the rotating part 3 is not limited to being formed in a cylindrical shape, and may be formed in a shape whose diameter changes in the axial direction, such as a sphere or an oval sphere. In this case, in order to accurately measure the amount of vibration by the rotation measurement part 4, it is preferable to use a pair of holding members 8, 8, etc. to prevent the part of the rotating part 3 that contacts the object from shifting in the axial direction. [Explanation of symbols]

[0064] 1,1B,1C,1D Motion measurement device 2 Base 3 Rotating section 4 Rotation measurement section 5 Pressing mechanism 6 Moving mechanism 7 Swivel mechanism 8 Retaining member 9 Clamping unit 40 Scraper 81 Guide inclined part 100 Ship (Structure) 200 Offshore Facilities (Target) 201 Boat Landing Bar (Object) P11 Storage position P12 Usage position

Claims

1. A base portion that is attached to a structure; A rotating part that is rotatably attached to the base part and contacts an object; A rotation measuring unit that measures the number of rotations of the rotating unit; A motion measurement device comprising:

2. 2. The motion measurement device according to claim 1, wherein the rotating portion is cylindrical and has a diameter that does not change in the axial direction.

3. 3. The motion measurement device according to claim 1, further comprising a pressing mechanism provided between the base portion and the rotating portion, for pressing the rotating portion against the object.

4. 3. The motion measurement device according to claim 1, further comprising a movement mechanism provided between the base portion and the rotating portion for moving the rotating portion between a storage position close to the base portion and a usage position away from the base portion.

5. 3. The motion measurement device according to claim 1, further comprising a rotation mechanism provided between the base section and the rotating section, for rotating the rotating section relative to the base section.

6. 3. The motion measurement device according to claim 1, further comprising a pair of holding members provided at both axial ends of the rotating part, the holding members positioning the object therebetween with at least the rotating part in contact with the object.

7. 7. The motion measurement device according to claim 6, wherein at least one of the pair of retaining members has a guide inclined portion that inclines so as to move away from the other retaining member in the axial direction as the retaining member moves away from the rotating portion in the radial direction of the rotating portion.

8. 7. The motion quantity measuring device according to claim 6, further comprising a clamping unit that, as the object comes into contact with the rotating part, narrows the gap between the pair of holding members to clamp the object between the pair of holding members, and, as the object moves away from the rotating part, widens the gap between the pair of holding members to release the object from being clamped by the pair of holding members.

9. 3. The motion measurement device according to claim 1 or 2, further comprising a scraper arranged radially adjacent to the rotating part and configured to scrape the surface of the object at least while the object is in contact with the rotating part.

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