JP5970363B2 - Crane ship and arithmetic control device for controlling crane ship - Google Patents

Description

  The present invention relates to a crane ship in which a crane is provided on a hull. Moreover, it is related with the arithmetic and control apparatus which controls this crane ship.

  A crane ship that lifts a suspended load on water is operated in a state where the hull is stopped at a predetermined position. As a method of stopping the crane ship at a predetermined position, there are a method of mooring the hull to the anchor, a method of pushing a columnar spud from the hull to the bottom of the water, and a method of using both of them together. However, in the method using an anchor, the anchor itself may move and the crane ship is washed away, and the method of pushing the spud to the bottom of the water is very large, and depending on the location, the spud is pushed to the bottom of the water. It can be difficult.

  On the other hand, a ship that performs fixed point holding control to hold the hull at a target position (fixed point) while maintaining a balance with a plurality of propulsion devices has been proposed (see, for example, Patent Document 1). According to this fixed point holding control, the hull can be held at a predetermined target position against the external force of wind, tidal current, and waves.

JP-A-9-267798

  In the fixed point holding control described above, it is necessary to always generate thrust in each propulsion unit in order to hold the hull at the target position against the external force of wind, tidal current, and waves. On the other hand, when the water flow is directed inward (thrust is outside the hull), problems such as loss of thrust and generation of vibration due to the water flow hitting the bottom of the ship occur. For these reasons, during the fixed point holding control, each propeller is often operated so that the thrust is directed to the inside of the hull, that is, the water is jetted to the outside of the hull. .

  Then, when the hull of the crane ship is held at a fixed point, when a dropping operation is performed to drop the suspended load on the water surface or in the water, a large force may be applied to the suspended load by the water ejected from the propulsion device. In this case, the suspended load may become unstable due to tilting or shaking in the water, or the suspended load may be washed away, which may hinder the dropping operation.

  The present invention has been made in view of such circumstances, and when a hull is held at a fixed point by a plurality of propulsion devices, a suspended load dropped by a crane is unstable or washed away in the water surface or in water. An object of the present invention is to provide an arithmetic control device that controls a crane ship that can be suppressed.

  An arithmetic and control unit according to an aspect of the present invention includes a hull, a crane that is rotatably provided on the hull, and that drops a suspended load on the surface of the water or in water, and a propulsion system configured redundantly by a plurality of propulsion devices. And a control device for controlling the crane to hold the hull at a fixed point while performing a limited operation to reduce the amount of water ejected from the propulsion device toward the dropping position of the suspended load. Do.

  Here, “redundantly configured” means that there are a plurality of combinations of thrust distribution by each propulsion device for generating a force in an arbitrary direction on the hull. In addition, “control to hold the hull at a fixed point” includes not only “automatic fixed point hold” in which the hull is automatically held at a fixed point by capturing the hull position with GPS or the like, but also the joystick etc. “Manual fixed point holding” in which the hull is held at a fixed point by manual operation is also included. According to the above configuration, when the hull is held at a fixed point, the amount of water discharged from the plurality of propulsion devices toward the dropping position of the suspended load is reduced, so the force received by the suspended load by the water ejected from the propulsion device Can be reduced.

  In the above-described arithmetic control device, the limited operation may be performed by stopping at least one propulsion unit that affects the drop position by a water flow.

  Further, in the above-described arithmetic control device, the limited operation is configured such that at least one propulsion device that influences a water flow at the dropping position ejects water in a direction different from the direction of the dropping position. May be.

  In the above-described arithmetic control device, the limited operation may be performed by reducing the amount of water ejected by at least one propulsion device that affects the drop position by a water flow.

  Further, in the above-described arithmetic control device, at least one of the plurality of propulsion devices is a propulsion device having a propeller, and the arithmetic control device is configured such that the propulsion device having the propeller influences a water flow on the dropping position. When it becomes a propulsion device, it may be configured to reduce the rotational speed, pitch, or both of the propeller.

  Further, in the above arithmetic control device, at least one of the plurality of propulsion devices is a propulsion device having a water jet pump, and the arithmetic control device is configured such that the propulsion device having the water jet pump has a water flow at the dropping position. The output of the water jet pump may be reduced when the propulsion device is affected.

  In the above-described arithmetic control device, at least one of the plurality of propulsion devices may be a swivel propulsion device, a rudder propulsion device combining a propeller and a rudder, or a side thruster.

  Further, in the above arithmetic control device, the control for holding the hull at a fixed point may be automatic fixed point holding control for automatically holding the hull at a fixed point based on a value including a measured value of the hull position and a target value of the hull position. Good. According to this configuration, it is possible to reduce the burden on the crew as compared with the case of manual fixed point holding control.

  Furthermore, the crane ship which concerns on a certain form of this invention is equipped with said calculation control apparatus.

  As described above, according to the arithmetic and control unit according to the present invention, the force received by the suspended load by the water ejected from the propulsion device can be reduced. As a result, it is possible to prevent the suspended load dropped by the crane from becoming unstable or flowing on the water surface or in the water.

FIG. 1 is a schematic side view of a crane ship according to the first embodiment of the present invention. FIG. 2 is a schematic plan view of the crane ship according to the first embodiment of the present invention. FIG. 3 is a block diagram of a configuration related to the control of the first embodiment of the present invention. FIG. 4 is a schematic side view of a crane ship according to a modification of FIG. FIG. 5 is a flowchart of the operation related to the fixed point holding of the crane ship according to the first embodiment of the present invention. FIG. 6 is a diagram showing the relationship between the crane rotation angle and the propulsion device in the first embodiment of the present invention. FIG. 7 is a schematic plan view of a crane ship according to the second embodiment of the present invention. FIG. 8 is a schematic plan view of a crane ship according to the third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described. In the following description, the same or corresponding components are denoted by the same reference symbols throughout the drawings, and redundant description is omitted.

(First embodiment)
First, with reference to FIG. 1 thru | or FIG. 3, the structure of the crane ship 100 which concerns on 1st Embodiment of this invention is demonstrated. FIG. 1 is a schematic view of a crane ship 100 according to the present embodiment, FIG. 2 is a plan view of the crane ship 100 according to the present embodiment, and FIG. 3 is a block diagram of a configuration relating to control of the present embodiment. As shown in FIG. 1, the crane ship 100 includes a hull 10, a propulsion system 20, a crane 30, and an arithmetic control device 40. Hereinafter, these components will be described in order.

  The hull 10 is a portion serving as a base of the crane ship 100. Among the hulls 10 shown in FIGS. 1 and 2, the right side of the drawing is the bow and the left side of the drawing is the stern (the same applies to FIGS. 4, 7 and 8). A crane 30 which will be described later is disposed in a central portion between the bow and stern of the hull 10. The hull 10 is equipped with a position measuring device 11 for measuring the hull position (the center position of the hull 10) and a gyro compass 12 for measuring the bow turning angle (head direction). Further, as shown in FIG. 3, the position measurement device 11 transmits a signal related to the measurement value of the hull position to the arithmetic control device 40 described later. Similarly, the gyro compass 12 transmits a signal related to the measured value of the bow turning angle to the arithmetic and control unit 40 described later.

  The propulsion system 20 is a system for propelling the hull 10. More specifically, the propulsion system 20 is a system for turning and translating the hull 10. The "turning motion" here refers to a motion that turns (turns) around a certain point on the hull, and the "translational motion" refers to a motion that moves forward, backward, left and right while keeping the bow direction constant. The propulsion system 20 includes four propulsion units, a first propulsion unit 21, a second propulsion unit 22, a third propulsion unit 23, and a fourth propulsion unit 24 in order counterclockwise from the upper right side (left side of the bow) of FIG. have. Each propulsion device 21 to 24 has the same configuration, and thrust can be obtained by ejecting water. As shown in FIG. 2, each propulsion device 21 to 24 is arranged on the bottom surface of the hull 10 so as to surround the crane 30. The centers of these propulsion devices 21 to 24 coincide with the rotation center of the crane 30.

  In the present embodiment, each propulsion device 21 to 24 is a swivel propulsion device having a propeller 25. Each propulsion device 21 to 24 does not have a rudder, and can adjust the direction in which it turns and ejects water. That is, the thrust direction can be changed. Further, each propulsion device 21 to 24 is configured to change the rotation speed of the propeller 25. If the rotation speed of the propeller 25 is reduced, the amount of water ejected (that is, thrust) is reduced. Each propeller 25 may be a variable pitch propeller (Controllable Pitch Propeller) that can change the pitch (blade angle), and a fixed pitch propeller (Fixed Pitch Propeller) that cannot change the pitch (wing angle). ). When the propeller 25 is a variable pitch propeller, the amount (namely, thrust) of the water to be ejected can be reduced by reducing the pitch (blade angle).

  Further, the propulsion system 20 is configured to be “redundant” by the propulsion devices 21 to 24. That is, the propulsion system 20 is configured such that there are a plurality of combinations of thrust distribution by the propulsors 21 to 24 for generating a force in an arbitrary direction on the hull 10. For example, if a thrust can be generated by a plurality of propellers and the hull can be moved, if each propeller can generate a thrust of a different direction and size and move the hull in the same direction, It can be said that the propulsion system composed of the propulsion devices is configured redundantly. Since the propulsion system 20 of the present embodiment is configured redundantly, even if one of the propulsors 21 to 24 is stopped (that is, even if the thrust is zero), the remaining three propulsors A force in an arbitrary direction can be generated on the hull 10.

  In the present embodiment, a swivel propulsion device having a propeller 25 is employed as each of the propulsion devices 21 to 24, but a propulsion device having other than the propeller may be employed as a mechanism for ejecting water. For example, each propulsion device 21 to 24 may be configured as shown in FIG. FIG. 4 is a schematic side view of a crane ship 100 according to a modification of the present embodiment. As shown in FIG. 4, in this modification, the stern side propulsors 22 and 23 are swivel propulsors having a propeller 25, but the bow side propulsors 21 and 24 are water jet pumps (Water Jet pumps). Pump) 26 is configured so that the direction in which the tip portion turns and the water is ejected can be changed. That is, the propulsion devices 21 and 24 of this modification are swivel propulsion devices having the water jet pump 26. The water jet pump 26 pressurizes water sucked from a water suction port 27 formed at the bottom of the hull 10 and jets the pressurized water from the tips of the propulsors 21 and 24. Thereby, both thrusters 21 and 24 can obtain thrust. In addition, in the modification shown in FIG. 4, although the front-end | tip part of the propelling devices 21 and 24 is comprised so that a 360 degree neck may be swung, it replaces with this and the structure of a front-end | tip part is -30 degrees-+30 degrees. You may have what has the deflector which shakes a head in a range, and changes the injection direction to the left-right direction, and the reverser which changes an injection direction back and forth.

  The crane 30 is a device that lifts the suspended load 101. The crane 30 is provided in the hull 10 and has a boom 31. A hanging tool 34 is suspended from the tip of the boom 31 via a wire 33 so as to be lifted and lowered. The hanging tool 34 of the present embodiment is a hook for hanging the suspended load 101, but instead of this, it may be a bucket that picks up the sediment on the bottom of the water (in this case, the sediment or bucket becomes the “suspended load”). ). The crane 30 is configured to be rotatable with respect to the hull 10. In other words, the crane 30 is configured to be able to adjust the rotation angle θ. In the present embodiment, the length of the boom 31 of the crane 30 is constant, but the boom 31 may be configured to be able to expand and contract. As shown in FIG. 3, the crane 30 transmits a signal related to the rotation angle θ of the crane 30 to the arithmetic control device 40 described later.

  The arithmetic control device 40 is a device that includes a CPU or the like and controls the propulsion system 20. The arithmetic and control unit 40 controls the propulsion system 20 to turn (turn) and translate the bow of the hull 10 in an arbitrary direction. As shown in FIG. 3, the arithmetic and control unit 40 receives a signal related to the measured value of the hull position from the position measuring device 11, receives a signal related to the measured value of the bow turning angle from the gyrocompass 12, and receives the signal of the crane from the crane 30. A signal related to the rotation angle θ is received. Further, the arithmetic and control unit 40 receives signals relating to the target value of the hull position and the target value of the bow turning angle from the input setting unit 41. The input setting unit 41 is configured so that an operator can input coordinates and angles. Then, a target value of the hull position and a target value of the bow turn angle are set based on the coordinates and angle input by the operator. The target value of the hull position and the target value of the bow turning angle here are the position (fixed point) and the bow turning angle at which the hull 10 is to be held in the fixed point holding control, respectively. The arithmetic and control unit 40 performs fixed point holding control based on the measured value of the hull position, the measured value of the bow turn angle, the target value of the hull position, and the target value of the bow turn angle. A specific control method will be described later.

  Next, with reference to FIG.5 and FIG.6, the operation | movement regarding fixed point holding | maintenance of the crane ship 100 which concerns on this embodiment is demonstrated. FIG. 5 is a flowchart of the operation related to the fixed point holding of the crane ship 100 according to the present embodiment. The operations described below are performed under the control of the arithmetic and control unit 40.

  First, the arithmetic and control unit 40 acquires the measured value of the hull position from the position measuring device 11, and acquires the measured value of the bow turning angle from the gyrocompass 12 (step S1). As described above, the arithmetic and control unit 40 receives the signal related to the measurement value of the hull position and the signal related to the measurement value of the bow turning angle from the position measurement device 11 and the gyrocompass 12, respectively. For example, the measured value of the hull position and the measured value of the bow turning angle can be obtained (calculated).

  Subsequently, the arithmetic and control unit 40 measures the hull position target value and the bow turn angle target value preset by the operator by the input setting unit 41, and the hull position measurement value and bow turn angle obtained in step S1. The translational resultant force acting on the hull 10 (hereinafter referred to as “necessary translational resultant force”) and the turning moment resultant force (hereinafter referred to as “necessary turning moment resultant force”) required for the values to coincide with each other are calculated (hereinafter referred to as “necessary turning moment resultant force”). This calculation is referred to as “control calculation” (step S2). In this control calculation, the required propulsion resultant force and the required turning moment resultant force are calculated based on not only the deviation between the current measured value and the target value but also the past deviation information and the future predicted deviation information.

  Subsequently, the arithmetic and control unit 40 acquires the rotation angle θ of the crane from the crane 30 (step S3). As described above, since the arithmetic and control unit 40 receives a signal related to the rotation angle θ from the crane 30, the calculation and control device 40 can acquire (calculate) the rotation angle θ of the crane 30 based on this signal.

  Subsequently, the arithmetic and control unit 40 selects a propulsion device that influences the water flow at the dropping position at which the suspended load 101 of the crane 30 is dropped (step S4). Specifically, based on the rotation angle θ of the crane 30, a propulsion device close to the dropping position is selected. In addition, even if it is a close propeller, it will not be selected if it does not affect the water flow. In the present embodiment, when the angle between the bow direction and the boom 31 of the crane 30 is defined as a rotation angle θ with reference to the bow direction as shown in FIG. 2, the rotation angle θ exceeds 0 ° and is 90 °. The first propulsion device 21 is selected in the case of up to 180 °, the second propulsion device 22 is selected in the case of over 90 ° to 180 °, and the third propulsion is performed in the case of over 180 ° to 270 °. The device 23 is selected, and if it exceeds 270 ° and reaches 360 °, the fourth propeller 24 is selected.

  Subsequently, the arithmetic and control unit 40 requires the translational force and the turning moment resultant force acting on the hull 10 by the thrust force of the remaining three thrusters, excluding the thruster selected in step S4, and the necessity calculated in step S2. A combination of the turning direction of each propeller and the rotational speed of the propeller 25 is selected (calculated) so that the translational resultant force and the required turning moment resultant force coincide (step S5). That is, the thrust distribution calculation of each propeller is performed. When the propeller 25 is a variable pitch propeller, the pitch of the propeller 25 is also included in the combination element.

  Subsequently, the arithmetic and control unit 40 operates each propulsion device based on the calculation result obtained in step S5 (step S6). That is, the arithmetic and control unit 40 performs fixed point holding control through steps S1 to S5. However, at this time, the arithmetic and control unit 40 stops the propulsion device that affects the drop position selected in step S4. Here, FIG. 6 is a diagram showing the relationship between the rotation angle θ of the crane 30 and the propulsion devices 21 to 24. In FIG. 6, the horizontal axis indicates the rotation angle θ of the crane 30, and the counterclockwise direction is positive with the bow direction being 0 °. The vertical axis indicates whether each propulsion device 21 to 24 is operating (ON) or stopped (OFF) with respect to the rotation angle θ of the crane 30. As shown in FIG. 6, the arithmetic and control unit 40 stops the first propeller 21 when the rotation angle θ of the crane 30 exceeds 0 ° and reaches 90 °, and exceeds 90 ° and 180 °. The second propulsion unit 22 is stopped in the case of up to 180 °, the third propulsion unit 23 is stopped in the case of over 180 ° to 270 °, and the fourth propulsion is performed in the case of over 270 ° to 360 °. The vessel 24 is stopped.

  In this way, the arithmetic and control unit 40 performs a limited operation for stopping the propulsion device that has an influence of the water flow on the dropping position based on the rotation angle θ of the crane 30. From this restricted operation, among the propulsion devices 21 to 24, the propulsion device that affects the water flow at the dropping position where the suspended load 101 of the crane 30 is dropped is stopped. Water is not ejected toward the drop position (suspended load 101). Therefore, even if it sees as the propulsion system 20 whole, the quantity of the water spouted toward a dropping position can be reduced (eliminated). That is, according to the crane ship 100 according to the present embodiment, the force received by the suspended load 101 by the water ejected from each of the propulsion devices 21 to 24 can be reduced, so that the suspended load 101 dropped by the crane 30 is reduced. It is possible to prevent the water surface from becoming unstable or flowing on the water. Moreover, since the propulsion system 20 is configured in a redundant manner, the hull 10 can be held at a fixed point even if the propulsion unit that influences the water flow at the dropping position is stopped.

  Further, as shown in FIG. 5, the arithmetic and control unit 40 is configured to repeat the steps S1 to S6 described above. In other words, the arithmetic and control unit 40 is arranged so that the state is maintained when the hull 10 matches the target position (fixed point), and moves toward the target position when the hull is deviated from the target position. Steps S1 to S6 are repeated. The above is description of operation | movement regarding fixed point holding | maintenance of the crane ship 100 of this embodiment.

  In the present embodiment, the limited operation by the arithmetic and control unit 40 is performed by stopping the propulsion device that affects the drop position by the water flow, but the limited operation is not limited to such a case. For example, the limited operation may be performed by ejecting water in a direction different from the direction of the dropping position by a propulsion device that affects the water flow at the dropping position. Even with such a configuration, the amount of water ejected from the propeller closest to the dropping position to the dropping position (suspended load 101) can be reduced, so that the suspended load 101 dropped on the surface of the water or in the water is not suitable. It can be prevented from becoming stable or flowing.

  Furthermore, as another limited operation, it may be performed by reducing the amount of water itself ejected by the propulsion device that influences the water flow at the dropping position. As described above, in the case where each of the propulsion devices 21 to 24 has the propeller 25 as in the present embodiment, if the rotation speed, the pitch, or both of the propeller 25 is reduced, the propulsion device ejects. The amount of water can be reduced. Further, as in the modification example (see FIG. 4), when the propellers 21 and 24 on the bow side have the water jet pump 26, if the output of the water jet pump 26 is reduced, the propulsion device The amount of water to be ejected (injected) can be reduced.

(Second Embodiment)
Next, a crane ship 200 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic plan view of the crane ship 200 according to the present embodiment. As shown in FIG. 7, the crane ship 200 according to this embodiment includes a side thruster in which one of the three propulsion devices 221 to 223 constituting the propulsion system 220 ejects water leftward or rightward of the hull 10. (Side Thruster) is different from the crane ship 100 according to the first embodiment. Hereinafter, the propulsion system 220 of this embodiment will be mainly described.

  The propulsion system 220 according to this embodiment includes three propulsors, a first propeller 221 disposed on the bow side of the hull 10 and a second propulsion unit 222 and a third propulsion unit 223 disposed on the stern side. The propulsion devices 221 to 223 are redundantly configured. The first propeller 221 is a side thruster having a propeller 225. The first propulsion device 221 discharges water ejected by the propeller 225 to the outside of the hull 10 from the discharge port 226 formed on the left side or the discharge port 227 formed on the right side facing the bow direction of the hull 10, Thereby, thrust can be obtained in the left direction or the right direction. In addition, the propeller 225 of the first propulsion device 221 is configured to be able to change the rotation speed, and by reducing the rotation speed, it is possible to reduce the amount of water ejected (that is, thrust). The second propulsion device 222 and the third propulsion device 223 are swivel propulsion devices having a propeller 228, and the configuration thereof is the same as that of the first propulsion device 21 described in the first embodiment.

  Instead of the propeller 225 of the first propulsion device 221, the propeller 228 of the second propulsion device 222, and the propeller 228 of the third propulsion device 223, a water jet pump (water jet shown in FIG. Pump 26) may be used. In this case, by reducing the output of the water jet pump, it is possible to reduce the amount of water (that is, thrust) ejected by each propulsion device 221 to 223.

  Further, the arithmetic and control unit 40 holds the hull 10 at a fixed point while performing a limited operation for reducing the amount of water ejected toward the dropped position of the suspended load 101. Specifically, the crane 30 has a rotation angle θ that affects the drop of the suspended load 101 in the range of 0 ° to 90 ° and 270 ° to 360 °. When this happens, the first thruster (side thruster) 221 is stopped. However, when the suspended load 101 is dropped in front of the bow, the first propulsion device 221 ejects water to both sides, so that the suspended load 101 is not affected by the water flow. Therefore, in this case, the first propulsion device 221 does not have to be stopped. Further, when the angle exceeds 90 ° and reaches 180 °, the second thruster 222 is stopped, and when the angle exceeds 180 ° and reaches 270 °, the third thruster 223 is stopped. And even if there exists a propulsion device stopped in this way, since the propulsion system 220 is configured redundantly, the hull 10 is held at a fixed point by the remaining propulsion devices not stopped. According to such a configuration, for the same reason as in the case of the first embodiment, it is possible to prevent the suspended load 101 dropped on the water surface or in the water from becoming unstable or flowing.

  The limited operation is not limited to stopping the propulsion unit that affects the water flow at the dropping position, but is performed when the propulsion unit closest to the dropping position spouts water in a direction different from the direction of the dropping position. Also good. Regarding the first propulsion device (side thruster) 221, when the rotation angle θ of the crane 30 exceeds 0 ° and reaches 90 °, the propulsion device closest to the dropping position is the first propulsion device 221. In this case, the water ejected from the first propulsion device 221 may be discharged only from the right discharge port 227 without being discharged from the left discharge port 226.

  Furthermore, as another limited operation, it may be performed by reducing the amount of water itself ejected by the propulsion device that influences the water flow at the dropping position. As described above, when the propellers 221 to 223 are propellers having the propellers 225 and 228 as in the present embodiment, the propulsion can be achieved by reducing the rotation speed, the pitch, or both of the propellers 225 and 228. The amount of water spouted by the vessel can be reduced. Further, when each of the propulsion devices 221 to 223 is a propulsion device having a water jet pump, the amount of water ejected by the propulsion device can be reduced by reducing the output of the water jet pump.

(Third embodiment)
Next, a crane ship 300 according to a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic plan view of the crane ship 300 according to the present embodiment. As shown in FIG. 8, the crane ship 300 according to the present embodiment has a propulsion system propulsion system 321 to 323 constituting a propulsion system 320, one of which is a side thruster and two of which are a propeller and a rudder. It differs from the crane ship 100 which concerns on 1st Embodiment by the point which is a container. Hereinafter, the propulsion system 320 of this embodiment will be mainly described.

  The propulsion system 320 of the present embodiment includes three propulsors, a first propeller 321 disposed on the bow side of the hull 10 and a second propulsion unit 322 and a third propulsion unit 323 disposed on the stern side. The propulsion devices 321 to 323 are redundantly configured. The first thruster 321 is a side thruster having a propeller 325, and has the same configuration as the first thruster 221 described in the second embodiment. Further, the second propulsion device 322 and the third propulsion device 323 are rudder type propulsion devices having a propeller 328 and a rudder 329. In the second propulsion device 322 and the third propulsion device 323, the amount of water ejected (that is, thrust) can be adjusted by changing the rotation speed of the propeller 328, and the water ejected by changing the direction of the rudder 329. The ejection direction of the can be adjusted.

  Instead of the propeller 325 of the first propeller 321, the propeller 328 of the second propeller 322, and the propeller 328 of the third propeller 323, a water jet pump (see the water jet pump 26 in FIG. 4) is used. Also good. In this case, by reducing the output of the water jet pump, it is possible to reduce the amount of water (that is, thrust) ejected by each of the propulsion devices 321 to 323.

  Further, the arithmetic and control unit 40 holds the hull 10 at a fixed point while performing a limited operation for reducing the amount of water ejected toward the dropped position of the suspended load 101. The relationship between the crane rotation angle θ and the stop of each propulsion device 321 to 323 is the same as the pattern described in the second embodiment. The limited operation is not limited to stopping the propulsion unit that affects the water flow at the dropping position, but the propulsion unit that affects the water flow at the dropping position spouts water in a direction different from the direction of the dropping position. It may be done. As described above, the second propulsion device 322 and the third propulsion device 323 of the present embodiment can adjust the ejection direction of the water to be ejected by changing the direction of the rudder 329.

  In addition, the limited operation may be performed by reducing the amount of water that is ejected by the propulsion device that affects the drop position by the water flow. As described above, in the case where each of the propulsion devices 321 to 323 includes the propellers 325 and 328 as in the present embodiment, if the rotation speed, the pitch, or both of the propellers 325 and 328 are reduced, the propulsion is performed. The amount of water spouted by the vessel can be reduced. Moreover, when each propulsion device 321 thru | or 323 is a propulsion device which has a water jet pump, the quantity of the water which the propulsion device ejects can be reduced by reducing the output of a water jet pump.

  The crane ships 100, 200, 300 according to the first to third embodiments of the present invention have been described above, but the specific configuration is not limited to these embodiments, and the scope of the present invention is not deviated. Any change in design is included in the present invention. For example, in the above, if each propeller is divided by a mechanism for ejecting water, a propeller and a water jet pump can be used, and if divided by a method of adjusting (selecting) the ejection direction of the ejected water, It has been explained that a rudder type and a side thruster method can be used. However, the type of the propulsion device of the present invention is not limited to the above-described type, and even if a propulsion device other than the above-described type is used, the gist of the present invention is not deviated.

  In the above-described embodiment, the arithmetic and control unit 40 performs fixed point holding control for matching the measured value of the hull position (that is, the center position of the hull) and the target value of the hull position. It is not restricted to such a thing. That is, in the crane ship according to each embodiment, instead of the fixed point holding control described above, the calculation control device 40 holds the fixed point so that the tip position of the crane 30 and the target dropping position where the suspended load 101 is to be dropped coincide. Even if control is performed, the crane ship is included in the present invention.

  In the above, the control for holding the hull 10 at a fixed point is automatically performed by the arithmetic control device 40 based on the measured value of the hull position, the measured value of the bow turn angle, the target value of the hull position, and the target value of the bow turn angle. However, the control for holding the hull 10 at a fixed point is not limited to this. That is, even when the crew operates a joystick or the like according to the surrounding situation and the arithmetic and control unit 40 holds the hull 10 at a fixed point based on a signal from the joystick or the like (so-called “manual fixed point holding”). Included in the invention.

  The arithmetic and control unit according to the present invention is useful in the technical field of crane ships because it can suppress the suspended load dropped by the crane from becoming unstable or flowing on the water surface or in the water.

10 Hulls 20, 220, 320 Propulsion systems 21, 221, 321 First propulsion device 22, 222, 322 Second propulsion device 23, 223, 323 Third propulsion device 24 Fourth propulsion device 25, 225, 228, 325, 328 Propeller 26 Water jet pump 30 Crane 40 Arithmetic controller 100, 200, 300 Crane ship 101 Suspended load θ Rotation angle

Claims (9)

An arithmetic and control device for controlling a crane ship, comprising: a hull, a crane that is rotatably provided on the hull, and that drops a suspended load into the surface of the water or underwater; and a propulsion system configured redundantly by a plurality of propulsion devices. Because
An arithmetic and control unit that performs control to hold the hull at a fixed point while performing a limited operation to reduce the amount of water ejected from the propulsion device toward the dropping position of the suspended load.   The calculation control device according to claim 1, wherein the limited operation is performed by stopping at least one propulsion unit that affects the drop position by a water flow.   The calculation control device according to claim 1, wherein the limited operation is performed by ejecting water in a direction different from a direction of the dropping position by at least one propulsion unit that affects the dropping position by a water flow.   The calculation control device according to claim 1, wherein the limited operation is performed by reducing an amount of water ejected by at least one propulsion device that affects the drop position by a water flow.   At least one of the plurality of propulsion devices is a propulsion device having a propeller, and when the propulsion device having the propeller is a propulsion device having an influence of water flow on the dropping position, a rotation speed, a pitch, and the like of the propeller 5. The arithmetic control device according to claim 4, wherein both of them are reduced.   At least one of the plurality of propulsion devices is a propulsion device having a water jet pump, and when the propulsion device having the water jet pump becomes a propulsion device having an influence of water flow on the dropping position, the water jet pump The arithmetic control device according to claim 4, wherein the output of the control is reduced.   The calculation control according to any one of claims 1 to 6, wherein at least one of the plurality of propulsion devices is a swivel propulsion device, a rudder propulsion device combining a propeller and a rudder, or a side thruster. apparatus.   The control for holding the hull at a fixed point is automatic fixed point holding control for automatically holding the hull at a fixed point based on a value including a measured value of the hull position and a target value of the hull position. The arithmetic and control unit described in the section.   The crane ship provided with the arithmetic and control unit as described in any one of Claims 1 thru | or 8.

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