JP2009241738A - Fixed point holding system for one-shaft one-rudder type bow thruster ship and fixed point holding method therefor - Google Patents

Abstract

A fixed-point holding system and a fixed-point holding method for a single-axis single-steer bow thruster ship that can return to a fixed point obliquely rearward when moving diagonally forward even in a single-axis single-rudder bow thruster ship equipped with a tunnel-type bow thruster.
In a fixed point holding method for a one-axis one-rudder bow thruster ship equipped with a tunnel type bow thruster, when returning to a target point at the rear or diagonally rear of the hull, the target point is viewed from the hull by moving backward in the hull. Then, after reaching the position from the front to the front, it moves in the lateral direction of the hull toward the target point and returns to the target point.
[Selection] Figure 3

Description

  The present invention relates to a fixed point holding system and a fixed point holding method for a one-axis one-steer bow thruster ship equipped with a tunnel type bow thruster that can efficiently return to a target point (fixed point) obliquely rearward even when moving diagonally forward.

  For observation ships and research ships, it is necessary to maintain the position of the hull in the vicinity of a fixed point on the ocean in order to perform fixed-point observation (or investigation), and many automatic fixed-point holding devices and fixed-point holding methods have been proposed. (See, for example, Patent Documents 1 and 2).

  These automatic fixed point holdings are equipped with several thrusters and side thrusters so that thrust (control force) can be generated in all directions with respect to the hull. The thrust in the moving direction to the target point which is a fixed point is generated, and the hull is returned to the fixed point.

  On the other hand, many 1-axis 1-steer bow thruster ships equipped with tunnel type bow thrusters have been manufactured and used for observations and surveys. As shown in FIG. 5, in this one-shaft one-steer bow thruster ship 1, a first control force F <b> 1 is generated in the rear, diagonally forward, and lateral directions by the propeller 2 and the rudder 3. A control force F2 is generated. The combined control force Fa of the first control force F1 and the second control force F2 is any one of the front-rear direction, the diagonally forward direction, and the lateral direction, and the combined control force Fa can be generated in this range. However, for the following reason, the combined control force Fa cannot be generated in the diagonally backward direction.

  The lift generated by the rudder 3 is proportional to the square of the velocity of the flow flowing into the rudder 3, so that the propeller 2 is moved backward and the rudder 3 is traversed in an attempt to generate the control force in the diagonally backward direction. However, since the water flow of the propeller 2 flows in the bow direction during reverse travel, the flow flowing into the rudder 3 is approximately equal to the reverse travel speed. For this reason, since the reverse speed is slow when the fixed point is held, the lateral force generated is small even if the steering angle is taken during reverse travel, the lateral force cannot be generated while moving backward, and it cannot move diagonally backward. That is, the combined control force Fa cannot be generated in the oblique rear direction.

  In addition, in the azimuth type bow thruster in which the direction of the bow thruster can be rotated with respect to the hull instead of the tunnel bow thruster, it is possible to generate a propulsive force obliquely backward by changing the direction of the bow thruster.

  Therefore, fixed point holding control (DPS control) is not performed, and as shown in FIG. 6, when the vehicle deviates from a predetermined tolerance circle DPR2 centered on the fixed point DP, the bow is turned toward the fixed point DP and the target is turned. Automatic fixed point return control (DPR control) for returning to the range circle DPR1 has been performed (see, for example, Patent Document 3).

  In this automatic fixed point return control, as shown in FIG. 6, it is assumed that the hull 1 moves rearward from the fixed point position (A0) by an external force including wind force Fw, tidal force Ft, etc., and deviates from the allowable range DPR2 ( A1 to A3 in FIG. 6, the direction of the hull 1 is directed to the target point (fixed point) DP (A3 to A4 to A5), and then moved forward by propeller rotation (A5 to A6 to A7) and enters the target range DPR1 After that, the hull 1 is turned so that the direction of the hull 1 is directed to a predetermined direction (A7 to A8 to A9), thereby returning.

  On the other hand, when the direction of the external force changes and an external force is applied from the rear of the hull 1 and the hull 1 moves forward or obliquely forward from the fixed point position (A0) (B1), the reverse or diagonal Rather than proceeding backwards, the propeller, rudder and bow thruster are used to reverse the hull 1 and turn the bow toward the return DP (B2 to B3 to B4) before moving forward by propeller rotation. (B4 to B5 to B6), after entering the target range DPR1, the bow thruster is driven to return the direction of the hull 1.

  In other words, in order to return backward or obliquely backward, the bow is turned in the return direction and then moved forward to reach the target range, and further, the bow is turned in a predetermined direction by turning. Such control is automatic fixed point return control that has been performed in the prior art for ships that cannot generate a control force obliquely backward.

  However, recently, there are not a few cases in which observation (or investigation) exceeding a water depth of 3000 m is performed even in a single-shaft one-steering bow thruster ship equipped with this tunnel type bow thruster, and during that time, maneuvering that keeps the position and orientation of the ship is required, Performing such a ship maneuver for a long time is a heavy burden on the ship operator, and fixed point holding control is required. In particular, during observation, the observation equipment is placed in the sea or pulled, so changing the direction of the hull or turning the hull is disliked, and conventional automatic fixed point return control is not compatible. It's getting enough.

On the other hand, in order to perform the fixed point holding control of a ship that moves even obliquely backward in the prior art on the ocean, an actuator configuration that enables movement in all directions is required. In particular, in order to obtain the control force obliquely rearward, an azimuth thruster that can change the direction of the control force relative to the hull is required, and the direction of the control force that can be generated by the rudder and propeller is from the front to the side. In a 1-axis 1 rudder bow thruster ship that is limited in the rear direction, it is considered difficult to perform the fixed point holding control including the backward movement.
Japanese Patent Laid-Open No. 2005-254956 JP 7-165189 A Japanese Patent Application Laid-Open No. 7-235991

  The present invention has been made in view of such a situation, and its purpose is to overcome the preconceived preconception that propulsion in the direction is necessary for holding a fixed point, By disassembling into lateral propulsion and performing control to move diagonally backward in two stages, even in a 1-axis 1 rudder bow thruster ship equipped with a tunnel-type bow thruster, when moving diagonally forward, An object of the present invention is to provide a fixed point holding system and a fixed point holding method for a single-axis one-steer bow thruster ship that can be returned.

  In order to achieve the above object, a fixed point holding system for a 1-axis 1 rudder bow thruster ship according to the present invention is a fixed point holding system for a 1-axis 1 rudder bow raster ship equipped with a tunnel type bow thruster. When returning to the target point ahead or diagonally in front of the hull, calculate the control force in the direction to aim directly at the target point, and generate the control force against the force caused by the disturbance, propeller, rudder and tunnel When controlling the type bow thruster to move the hull back to the target point and returning to the target point behind or diagonally behind the hull, or when the calculated control force is behind or diagonally behind the hull The propeller is calculated so as to generate a backward advancing force corresponding to the backward component of the distance between the hull and the target point, and to generate the calculated backward control force against a force caused by a disturbance. The reverse movement control to be controlled and the lateral control force corresponding to the lateral component of the distance between the hull and the target point are calculated after the target point reaches the position from the front to the front when viewed from the hull. And a rearward movement control that performs a two-stage control of a lateral movement control that controls the propeller, the rudder, and the bow thruster so that the calculated lateral control force is generated against a force caused by a disturbance. .

  According to this configuration, in a one-axis one-steering bow-thruster ship equipped with a tunnel-type bow thruster that was considered difficult in the prior art, the hull is not turned around to a target point (fixed point) obliquely rearward. By first propelling backward (reversing) and then laterally propelling (transverse), the hull can be returned to the target point obliquely backward.

  In particular, by propelling laterally after reversing, the propeller thrust is increased when the reverse is stopped, compared to during reverse traveling.This increases the speed of the propeller wake and increases the amount of lateral force generated by the rudder. The lateral movement can be efficiently performed by using the lateral force due to and the lateral force of the bow thruster.

  In the fixed point holding system for the one-axis one-steer bow thruster ship described above, when the control device calculates the control force required to return to the target point, when the control force component to the rear of the hull is not included, When the movement control is performed and the control force component to the rear of the hull is included, the backward movement control is performed.

  Alternatively, in the fixed point holding system for the one-axis one-rudder bow thruster ship, when the control device calculates a target point, if the target point is in front of the hull or obliquely forward, the forward movement control is performed, When the target point is behind or obliquely behind the hull, the backward movement control is performed.

  With these configurations, backward movement control to an oblique rear position by two-stage propulsion of backward propulsion and lateral propulsion calculates the propulsive force directly in that direction, and distributes this calculated control force to each propulsion device Since the fixed point movement control in the case of including backward propulsion can be simplified, the fixed point holding control as a whole can be simplified.

  In this backward movement control, a backward advancing force corresponding to the backward direction component is generated, and then a lateral direction controlling force is generated. In the case of a fixed pitch propeller (FPP), the reverse control force is reduced when the external force (wind force, tidal force, etc.) that pushes the ship back is reduced to reduce the propulsion force by the propeller. The reverse control force by the propeller is obtained by reversing the rotation, but in the variable pitch propeller (CPP), the propulsion force by the propeller can be easily obtained from forward to reverse by changing the pitch of the propeller blades.

  Also, the lateral control force applies a water flow generated by the propeller rotation in the forward direction to the rudder and directs it in the lateral direction, thereby generating a first lateral control force in this portion and at the bow portion by the bow thruster. The second control force can be generated and the resultant control force can be used to proceed in the lateral direction. Further, since the lateral movement is actually started in a state where there is a reverse speed, the vehicle temporarily moves obliquely backward, and the effect of improving the control performance can be obtained.

  In actual operation, when fixed point holding control is performed, disturbance is often received in the bow direction, and backward movement control is rarely performed. The fixed point can be stably maintained even with the 1-axis 1-steer bow thruster ship provided.

  A fixed point holding method for a 1-axis 1-rudder bow thruster ship to achieve the above object is a fixed-point holding method for a 1-axis 1-rudder bow thruster ship equipped with a tunnel type bow thruster. When returning, after moving to the rear of the hull and reaching the position where the target point is located from the front to the front as seen from the hull, it moves in the lateral direction of the hull toward the target point and returns to the target point It is characterized by that.

  According to this method, in the fixed point holding control, when moving diagonally backward, the control in the front-rear direction and the control in the horizontal direction are sequentially switched. In other words, when moving to a target point diagonally backward, first, only the backward movement of the ship is performed, and after moving to the horizontal position of the target point, control is performed to move in the horizontal direction. Do. By controlling in such a way, even if a disturbance is received near the control target point, it is possible to deviate greatly from the vicinity of the control target point (fixed point) by repeating the control of backward movement and lateral movement. Therefore, it is possible to hold the fixed point efficiently.

  According to the fixed point holding system and fixed point holding method of the single-axis one-rudder bow thruster ship of the present invention, the propulsion is first carried out backward without turning the hull to the target point (fixed point) obliquely rearward, as in the prior art. By propelling laterally, the hull can be returned to the target point obliquely rearward.

  In particular, since the propeller thrust is increased more than when the vehicle is moving backward when it moves backward after moving backward, the speed of the propeller wake increases and the amount of lateral force generated by the rudder increases. The lateral movement can be efficiently performed by using the lateral force and the lateral force by the rudder.

  In the fixed point holding control, the fixed point movement control when including backward propulsion can be simplified, and the backward movement control to the oblique rear position by the two-stage propulsion of the backward propulsion and the lateral propulsion is directly propelled in that direction. The force can be calculated and separated from the forward movement control in which the calculated control force is distributed to each propulsion device. Therefore, the fixed point holding control as a whole can be simplified.

  DESCRIPTION OF EMBODIMENTS Embodiments of a fixed point holding system and a fixed point holding method for a single-axis one-steer bow thruster ship according to the present invention will be described below with reference to the drawings. Here, for simplification of description, the force, moment, and the magnitude and direction of the force, wind force, tidal force, external force, thrust, control force, etc. are used.

  As shown in FIG. 1, this 1-axis 1-steer bow thruster ship 1 has a propeller 2 and a rudder 3 at the stern part, and is provided with a tunnel-type bow thruster (hereinafter referred to as a bow thruster) 4 at the bow part. Further, in the fixed point holding control (DPS control), the one axis one rudder while maintaining the azimuth of the one axis one rudder bow thruster ship 1 at a predetermined azimuth α under the situation where the external force Fb such as the wind force Fw or the tidal force Ft acts. Control is performed so that the position SG of the specific portion of the bow thruster ship 1 is in the vicinity of the fixed point DP which is the target point. Also in this fixed point holding control, in order to avoid frequent control, a position holding allowable range DPS centered on the fixed point DP is provided. This position holding allowable range DPS is set in advance depending on the observation purpose, the investigation purpose, and the like.

  The one-axis one-rudder bow thruster ship 1 is configured to have a control system 10 including a fixed point holding system as shown in FIG. In this control system 10, the thrust of the propeller 2, the rudder angle of the rudder 3, and the thrust of the bow thruster 4 are controlled. In FIG. 2, the propeller 2 is constituted by a variable pitch propeller (CPP), and is driven by a main engine (engine) 5 via a speed reducer 6. The pitch angle control of the propeller 2, the rotational speed control of the main machine 5, the deceleration control of the speed reducer 6 and the like are performed by the engine monitoring control panel 11, and the propeller rotational speed Ne1 or the pitch angle β1 is controlled.

  In addition, the rudder 3 uses a rudder with a flap or a special rudder capable of turning off at a large angle so that a large lateral force can be generated, and the rudder angle γ is controlled by the steering unit 7. The steering machine 7 is controlled by a rudder control panel 12. The bow thruster 4 is formed in a tunnel type and has a variable pitch propeller inside. The bow thruster 4 is controlled by the thruster control panel 13 at the rotational speed Ne2 or the pitch angle β2.

  These control commands Ne1, Ne2 (or β1, β2), γ, and the like are output from the control panel 21 that performs control arithmetic processing. The control panel 21 is connected to a master switch panel 22 having a master display panel 22a, an extension cable 23a connected to a connector 23b, and a remote control panel 23 that can be operated even at a location away from the bridge, and is operated by an operator. Various instructions are input by.

  Further, the control panel 21 includes position information (ship position information) of a hull of a GPS sensor (positioning sensor using a global positioning system) 31 provided on the one-axis one-rudder bow thruster ship 1, and the wind direction of an anemometer 32. -Information of various sensors such as wind speed information, ship speed information of the ship speedometer 33, and heading of the gyrocompass 34 is also input. At the time of this input, data check is performed to check whether the input data is abnormal or filtering is performed.

  This control panel 21, master switch panel 22, remote operation panel 23, and the like constitute a control unit 20. In this control unit 20, operation information from the master panel switch panel 22, display panel 22a, remote operation panel 23, various sensors. Take in the information, calculate the control force necessary for hull movement, turning, heading maintenance, ship position maintenance, etc., and calculate the appropriate thrust distribution amount for propeller 2, rudder 3, bow thruster 4, The command signal to is output. When outputting the command signal, thrust fluctuation reduction processing is performed to prevent an overload from being applied to the propeller 2, the rudder 3, and the bow raster 4.

  The master switch panel 22 includes a joystick, a turning dial, a push button, a buzzer, and the like. Various modes are switched on the master display panel formed by the touch panel, various display functions, input / output processing of operation signals and the control panel. Perform communication processing. The remote operation panel 23 includes a joystick, a turn dial, various mode indicators, push buttons, a buzzer, and the like, and performs input / output processing of operation signals and communication processing between control panels.

  In addition to the automatic fixed point holding function in the fixed point holding mode, the control system 10 includes a standby function in the standby mode, a joystick maneuvering function in the OY mode, an automatic azimuth holding function in the azimuth holding mode, and an individual control in the individual mode. There are functions.

  In the present invention, the automatic fixed point holding function in the fixed point holding mode is configured as follows. The automatic fixed point holding function is a function of holding the ship position at the target position while holding the heading. As shown in FIG. 1, the heading head is deviated from the set heading α on the basis of the signal from the gyrocompass 34. Is controlled so as to be zero, and the ship position is controlled so that the deviation from the set position (fixed point) DP becomes zero based on a signal from a position sensor such as the GPS sensor 31. Further, a position holding allowable range DPS is provided for issuing a warning signal when the deviation from the target point DP becomes large.

  This automatic fixed point holding is performed according to a control flow as illustrated in FIG. When the fixed point holding mode of the automatic fixed point holding function is selected, the control flow of FIG. 3 starts. When this control flow starts, the movement to the fixed point DP is performed in step S11 of FIG. In the control of step S11, when the bow is advanced toward the predetermined fixed point DP and arrives at the fixed point DP, the bow direction is held at the predetermined direction α in the next step S12.

  With regard to the orientation maintenance in this automatic fixed point maintenance, the bow orientation changes due to disturbance, and if this orientation change is detected by a signal from the gyrocompass (azimuth angle detector) 34, based on the deviation between the bow orientation and the set orientation, The first azimuth holding control force F1d (including magnitude and direction) F1d of the propeller 2 and the rudder 3 and the second azimuth holding control force (only magnitude) F2d of the bow thruster 4 are calculated so that this deviation becomes zero. Based on the calculation result, feedback control such as PID control for operating the bow thruster 4, the propeller 2, and the rudder 3 is performed. As a result, the heading is maintained at the set direction.

  If the bearing can be maintained in step S12, the ship position is maintained in the next step S13. Regarding the ship position maintenance in this automatic fixed point maintenance, the wind direction / wind speed information is obtained from the wind direction anemometer 31 and the wind force Fw acting on the hull 1 in the direction maintained is calculated from the wind force data prepared in advance, and the external force Fb is calculated. calculate. A ship position holding control force (including a turning moment; the same applies hereinafter) Fas that opposes the external force Fb is calculated. Further, if necessary, a new ship position holding force including a heading holding control force by adding a combined force of the first heading holding control force F1d and the second heading holding control force F2d to the ship position holding control force Fas. The control force is Fas.

  Based on the thrust distribution data prepared in advance for the ship position holding control force Fas, the first ship position holding control force F1s that the propeller 2 and the rudder 3 should generate and the second ship position holding that the bow thruster 4 should generate. The control force F2s is calculated. The rotational speed Ne1 of the propeller 2 (or the pitch angle β1 of the propeller) and the rudder angle γ of the rudder 3 are calculated from the first ship position holding control force F1s. Further, the rotational speed Ne2 of the bow thruster 4 (or the pitch angle β2 of the propeller) is calculated from the second ship position holding control force F2s. Further, the calculated rotational speeds Ne1, Ne2 (or propeller pitch angles β1, β2) and steering angle γ command values are output to the control panels 11, 12, 13 to generate the overall control force Fa, and the external force The movement of ship position SG is suppressed against Fb.

  However, since disturbances such as wind direction, wind speed, and tidal current change, the overall control force Fa of the hull 1 is defeated by the external force Fb, or the hull 1 is flowed, or the overall control force Fa of the hull 1 is greater than the external force Fb. The hull 1 moves. This movement amount is checked in step S14.

  In the check of step S14, while the hull 1 is within the position holding allowable range DPS (YES), the movement control is not performed, but the hull 1 deviates outside the position holding allowable range DPS (NO ) Is detected by the GPS sensor 31, the process goes to step S <b> 20 to perform control for movement. In the control for movement in step S20, the deviation (direction and distance) between the ship position SG and the fixed point DP is calculated, and the overall movement control force Fam for moving the hull 1 in this direction is calculated, and in step S21. It is checked whether forward movement control is to be performed.

  In the check of step S21, when the overall movement control force Fam has a forward component of the hull 1 (when it is a forward or diagonally forward force), and when it is only a lateral component (lateral force) (If YES), since a control force can be generated in that direction, forward movement control is performed in step S22a of step S22 to move directly in the fixed point direction.

  In this forward movement control, the overall movement control force Fam is calculated based on the distance between the ship position SG and the fixed point DP. More specifically, feedback control is performed so that the distance between the ship position SG and the fixed point DP becomes zero by making it proportional to the magnitude of the distance between the ship position SG and the fixed point DP or proportional to the amount of change in the distance. . The overall movement control force Fa and the overall ship position holding control force Fas are combined (added by vectors) to calculate the overall control force Fa.

  Based on the thrust distribution data prepared in advance, the first control force F1t to be generated by the propeller 2 and the rudder 3 and the second control force F2t to be generated by the bow thruster 4 are calculated for the overall control force Fa. The rotation speed Ne1 of the propeller 2 (or the pitch angle β1 of the propeller) and the rudder angle γ of the rudder 3 are calculated from the first control force F1t. Further, the rotational speed Ne2 of the bow raster 4 (or the pitch angle β2 of the propeller) is calculated from the second control force F2t.

  Further, the calculated rotational speeds Ne1, Ne2 (or propeller pitch angles β1, β2) and steering angle γ command values are output to the control panels 11, 12, 13 to generate the overall control force Fa, and the external force The hull 1 is moved in the direction of the fixed point DP while resisting Fb. Since the calculated value of the overall movement control force Fam is controlled to become smaller as the fixed point DP is approached, the hull 1 enters the position holding allowable range DPS. In step S22b, it is determined whether or not the hull 1 has entered the position holding allowable range DPS. If not (NO), the process returns to step S22a, and if so (YES), the process returns to step S12, where Control of holding and ship position is performed.

  On the other hand, as shown in FIG. 4, the total movement control force Fam calculated based on the deviation (direction and distance) L between the ship position SG and the fixed point (target point) DP is If it has a rear component, that is, if there is a fixed point DP behind or diagonally rearward of the ship position SG (NO), control power cannot be generated diagonally backward, so go to step S23 and The backward movement control is performed in which the movement is divided into two stages, that is, the backward movement control in the first stage in step S23a and the lateral movement control in the second stage in step S23c.

  In the reverse movement control in the first stage of step S23a, only the reverse control force Fcm is calculated based on the backward component Lx of the hull 1 at the distance L between the ship position SG and the fixed point DP. At this stage, the lateral component Ly of the hull 1 at a distance L between the ship position SG and the fixed point DP is ignored. The reverse control force Fcm is defined as the overall movement control force Fam. More specifically, the distance between the ship position SG and the fixed point DP is proportional to the magnitude of the backward component Lx of the distance between the ship position SG and the fixed point DP or proportional to the amount of change of the backward component Lx. Feedback control is performed so that the backward component Lx becomes zero. The overall control force Fa is calculated by combining the overall movement control force Fam and the overall ship position maintaining control force Fas.

  Based on the thrust distribution data prepared in advance, the first control force F1t to be generated by the propeller 2 and the rudder 3 and the second control force F2t to be generated by the bow thruster 4 are calculated for the overall control force Fa. The rotation speed Ne1 of the propeller 2 (or the pitch angle β1 of the propeller) and the rudder angle γ of the rudder 3 are calculated from the first control force F1t. Further, the rotational speed Ne2 of the bow raster 4 (or the pitch angle β2 of the propeller) is calculated from the second control force F2t. Further, the calculated rotational speeds Ne1, Ne2 (or propeller pitch angles β1, β2) and steering angle γ command values are output to the control panels 11, 12, 13 to generate the overall control force Fa, and the external force While resisting Fb, the hull 1 is moved backward and moved directly to the side of the fixed point DP. As the hull rearward component Lx between the ship position SG and the fixed point DP approaches zero, the calculated value of the total movement control force Fam of only the reverse drive control force Fcm is controlled to be smaller. 1 retreats to the side of the fixed point DP. In step S23b, it is checked whether or not the hull 1 has reached the side of the fixed point DP. If it has reached (YES), it goes to the lateral movement control in the next step S23c, and if it has not reached (NO). Then, the process returns to the backward movement control in step S23a.

  In step S23b, when the GPS sensor 31 detects that the hull 1 has retracted to the side of the fixed point DP, the process proceeds to the second-stage lateral movement control in step S23c. In the second-stage lateral movement control, only the lateral control force Fdm is calculated based on the lateral component Ly of the hull 1 between the ship position SG and the fixed point DP. At this stage, the backward component Lx of the hull 1 with the distance L between the ship position SG and the fixed point DP is ignored. More specifically, the distance between the ship position SG and the fixed point DP is made proportional to the magnitude of the lateral component Ly of the distance L between the ship position SG and the fixed point DP, or in proportion to the amount of change of the lateral component Ly. Feedback control is performed so that the lateral component Ly of L becomes zero. The lateral movement control force Fdm is defined as an overall movement control force Fam. The overall control force Fa is calculated by combining the overall movement control force Fam and the overall position holding control force Fas.

  Based on the thrust distribution data prepared in advance, the first control force F1t to be generated by the propeller 2 and the rudder 3 and the second control force F2t to be generated by the bow thruster 4 are calculated for the overall control force Fa. The rotation speed Ne1 of the propeller 2 (or the pitch angle β1 of the propeller) and the rudder angle γ of the rudder 3 are calculated from the first control force F1t. Further, the rotational speed Ne2 of the bow raster 4 (or the pitch angle β2 of the propeller) is calculated from the second control force F2t.

  The calculated rotational speeds Ne1, Ne2 (or propeller pitch angles β1, β2) and steering angle γ command values are output to the control panels 11, 12, 13 to generate the overall control force Fa, and to the external force Fb. While resisting, the hull 1 moves sideways and moves to the fixed point DP. As the lateral component Ly of the hull 1 between the ship position SG and the fixed point DP approaches zero, in other words, as the fixed point DP approaches, the overall movement control force Fam of only the lateral control force Fdm. Since the calculated value is controlled to be small, the hull 1 falls within the position holding allowable range DPS. In step S23d, it is determined whether or not the hull 1 has entered the position holding allowable range DPS. If not (NO), the process returns to step S23c. If so (YES), the process returns to step S12. Control of bearing and ship position is performed.

  By performing the forward movement control and the backward movement control, when the fixed point DP is in the forward direction, the diagonally forward direction, the lateral direction and the true rear direction of the hull 1, the fixed point DP is moved directly in that direction. When the hull 1 is in an obliquely rearward direction, it moves in the fixed point DP direction in two stages by the first-stage reverse movement control and the subsequent second-stage lateral movement control, and is within the position holding allowable range DPS. Then, it shifts to ship position holding control.

  In the above description, when the control force (control force for overall movement) Fam necessary for returning to the fixed point (target point) DP is calculated in the check in step S21, the control force component to the rear of the hull is not included. In some cases, the forward movement control is performed, and when the control force component to the rear of the hull is included, the backward movement control is performed. However, when the target point DP is calculated, the target point DP is in front of the hull 1 or obliquely. The forward movement control may be performed when the vehicle is ahead, and the backward movement control may be performed when the target point DP is behind or obliquely behind the hull 1. When the vehicle is behind or obliquely rearward, the calculation of the first overall movement control force Fam is omitted, and the reverse drive control force Fcm is calculated. Therefore, the control can be simplified accordingly.

  While the fixed point holding mode is selected, the control of each step such as steps S12 to S22b or steps S12 to S23d is repeatedly performed. However, when selection other than the fixed point holding mode is performed, An interrupt occurs, the process proceeds to return, and the control flow in FIG. 3 ends.

  Note that the standby function is a function for outputting a command for setting the pitch angle of the propeller 2 to the hull stop blade angle, the rudder angle of the rudder 3 to zero, and the thrust of the bow thruster 4 to zero for each actuator. The joystick ship maneuvering function is a function of maneuvering with a joystick and a turning dial, and the ship can be moved forward and backward, turned, obliquely moved forward, turned, moved laterally, and the like by a combination of operations of the joystick and the turning dial. Since this function does not have an automatic bearing function, the bearing changes with disturbance or ship movement.

  The automatic bearing holding function is a function that performs feedback control based on the signal from the gyrocompass 34 so that the deviation from the set bearing becomes zero. Generate control force to move. The movable direction is the same as the joystick maneuvering function. The individual control function is a function of individually controlling the wing angle of the propeller 2 of the propeller 2 by the forward / backward operation of the joystick and the rudder angle of the rudder 3 by the operation of the turning dial.

  According to said structure, the fixed point holding | maintenance system of the 1 axis 1 rudder bow thruster ship 1 is comprised including the back movement control which performs two steps of control of forward movement, reverse movement control, and lateral movement control.

  Then, when the control device 20 of the fixed point holding system returns to the target point (fixed point) DP forward or obliquely forward of the hull 1, it calculates the control force in the direction directly aiming at the target point DP, and the calculated control force is Forward movement control is performed to control the propeller 2, the rudder 3, and the tunnel bow thruster 4 so as to resist the force (external force) Fb caused by the disturbance and to return the hull 1 to the target point DP.

  Further, when returning to the target point DP behind or obliquely behind the hull 1, a reverse control force Fcm corresponding to the backward component Lx of the distance L between the hull 1 and the target point DP is calculated, and this calculated reverse drive Backward movement control for controlling the propeller 2 so as to generate the control force Fcm against the force (external force) Fb caused by disturbance, and after the hull 1 reaches the side of the target point DP, the hull 1 and the target point The lateral control force Fdm corresponding to the lateral component Ly of the distance L from the DP is calculated, and the propeller 2 and the rudder 3 are generated so that the calculated lateral control force Fdm is generated against the force of disturbance. A lateral movement control for controlling the bow raster 4 is performed.

  With these controls, in the fixed point holding method for the 1-axis 1 rudder bow thruster ship, when returning to the target point DP behind or obliquely behind the hull 1, the hull 1 moves backward and reaches the side of the target point DP. Later, it can move back in the lateral direction of the hull 1 toward the target point DP and return to the target point DP.

  Therefore, according to the fixed point holding system and fixed point holding method of the above-described one-axis one-rudder bow thruster ship, the first propulsion is performed without turning the hull 1 to the target point (fixed point) DP on the oblique rear side as in the prior art. Then, the hull can be returned to the target point DP obliquely rearward by propelling laterally.

  In particular, by propelling laterally after reverse traveling, the propeller thrust is increased more than during reverse traveling when stopping reversely, so the speed of the propeller wake increases and the amount of lateral force generated by the rudder increases. Therefore, the lateral movement can be efficiently performed using the lateral force of the bow thruster and the lateral force of the rudder.

  In the fixed point holding control, the fixed point movement control when including backward propulsion can be simplified, and the backward movement control to the oblique rear position by the two-stage propulsion of the backward propulsion and the lateral propulsion is directly propelled in that direction. The force can be calculated and separated from the forward movement control in which the calculated control force is distributed to each propulsion device. Therefore, the fixed point holding control as a whole can be simplified.

It is a top view which shows the structure of the 1 axis | shaft 1 rudder bow thruster ship of embodiment which concerns on this invention, the direction of fixed point holding | maintenance control, the relationship between a fixed point, and a ship position. It is a figure which shows the structure of the control system of the 1 axis | shaft 1 rudder bow thruster ship of embodiment which concerns on this invention. It is a figure which shows an example of the control flow of fixed point holding | maintenance control of embodiment which concerns on this invention. It is a figure for demonstrating back movement control of embodiment which concerns on this invention. It is a figure which shows the advancing direction of the 1 axis | shaft 1 rudder bow thruster ship provided with the tunnel type bow thruster. It is a figure for demonstrating the automatic fixed point return control of a prior art.

Explanation of symbols

1 1 axis 1 rudder bow thruster ship 2 propeller 3 rudder 4 tunnel type bow thruster 10 control system (including fixed point holding system)
20 Control unit 21 Control panel 31 GPS sensor 32 Wind direction anemometer 33 Ship speed meter 34 Gyrocompass DP Fixed point (target point)
DPS Position holding allowable range Fa Overall control force Fam Overall movement control force Fas Position holding control force Fb External force Fcm Reverse drive control force Fdm Lateral drive control force F1d First heading hold control force F1s First ship position holding control force F1t First control force F2d Second azimuth holding control force F2s Second ship position holding control force F2t Second control force Ft Tidal force Fw Wind power Ne1 Propeller rotation speed (propeller)
Ne2 propeller rotation speed (bow thruster)
SG ship position (position of a specific part of the hull)
α Predetermined direction (set direction)
β1 pitch angle (propeller)
β2 pitch angle (bow thruster)
γ Rudder angle

Claims (4)

In a fixed point holding system for a 1-axis 1 rudder bow thruster ship equipped with a tunnel-type bow thruster, when the control device of the fixed point holding system returns to a target point forward or obliquely forward of the hull, a control force in a direction to directly aim at the target point Forward movement control to return the hull to the target point by controlling the propeller, rudder, and tunnel type bow thruster so that the calculated control force is generated against the force of disturbance,
When returning to a target point behind or diagonally behind the hull, or when the calculated control force is behind or diagonally rearward of the hull, the vehicle travels backward corresponding to the backward component of the distance between the hull and the target point. Reversing movement control that controls the propeller so that the calculated backward control force is generated against the force of disturbance, and reaches the position where the target point is from the front to the front as seen from the hull After that, the lateral control force corresponding to the lateral component of the distance between the hull and the target point is calculated, and the propeller and rudder are generated so that the calculated lateral control force is generated against the force of disturbance. A fixed point holding system for a one-axis one-rudder bow thruster ship, comprising a rearward movement control that performs two-stage control, namely, a lateral movement control for controlling a bow thruster.   When the control device calculates the control force necessary to return to the target point, when the control force component to the rear of the hull is not included, the forward movement control is performed and the control force component to the rear of the hull is included. 2. The fixed point holding system for a one-axis one-rudder bow thruster ship according to claim 1, wherein the rearward movement control is performed when the two-way control is performed.   When the control device calculates the target point, the control unit performs the forward movement control when the target point is forward or diagonally forward of the hull, and the backward movement when the target point is rearward or diagonally backward of the hull. 2. The fixed point holding system for a 1-axis 1-rudder bow thruster ship according to claim 1, wherein control is performed.   In a fixed point holding method for a 1-axis 1-steer bow thruster ship equipped with a tunnel-type bow thruster, when returning to a target point at the rear or diagonally rear of the hull, the target point moves from the side of the hull so that the target point is viewed from the front side. A fixed point holding method for a one-axis one-rudder bow thruster ship characterized in that after reaching a forward position, the ship moves laterally toward the target point and returns to the target point.