Ship's heading control device and heading control method

Abstract

To provide an azimuth control device and an azimuth control method to calculate a proper control gain for any steering pattern during sailing while taking into consideration the changing direction and the influence of disturbances.SOLUTION: An azimuth control device for a ship has: an azimuth control part to output a rudder angle command signal to direct a ship in an intended travel direction based on an azimuth command signal, a yaw angle signal, and a yaw angle speed signal generated by an azimuth command generation part; a rudder angle control part to control a rudder based on the rudder angle command signal; and a control gain adjusting part that comprises a calculation capability determination part to determine whether frequency characteristics can be calculated based on the rudder angle signal, the yaw angle signal, and the yaw angle speed signal and, if the calculation capability determination part determines that the frequency characteristics can be calculated, adjusts the control gain of the azimuth control part by calculating the frequency characteristics of the yaw angle signal and the yaw angle speed signal for the rudder angle signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a vessel heading control device and a vessel heading control method. [Background technology]

[0002] There is a heading control device that steers a ship to set it on a specified course and maintain it. A ship's heading control device is also called a ship's automatic steering device or autopilot. A ship's heading control device controls the rudder to align the yaw angle, which is the rotation angle around the vertical axis passing through the center of gravity of the ship, with the commanded heading.

[0003] A ship's heading control device is a device that controls the rudder to make the ship's heading (yaw angle) follow the commanded heading. A rudder angle command is generated by multiplying the deviation between the commanded heading and the ship's heading by a specified control gain, and the rudder is controlled according to the rudder angle command. A ship's heading control device drives the rudder using a rudder drive unit. The rudder drive unit drives the rudder, inducing a yaw rate in the hull and changing the ship's heading.

[0004] In a ship's heading control system, the control gain must be optimized to prevent hull vibration from being exacerbated by disturbances to the ship, such as tidal currents, waves, wind and rain. The control gain can be determined based on hull parameters. However, the hull parameters vary with changes in ship speed, draft, etc.

[0005] Therefore, it is necessary to respond to changes in hull parameters. An actual ship is sailed and input data (rudder angle) and output data (heading) are accumulated. The input data (rudder angle) is input into a hull model that has been constructed with hull parameters provisionally determined in advance for the accumulated data group, and output data (heading) is calculated. A technology has been disclosed that adjusts (corrects) the hull parameters based on the results of a comparison between this calculated heading and the actually measured heading (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-321455 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the ship heading control device of Patent Document 1, the rudder angle offset and hull parameters that represent a disturbance model such as a tidal current are considered to be fixed values. The rudder angle offset is the amount of rudder adjustment required for the ship to proceed straight. Data on rudder angle commands and ship heading are accumulated, and the rudder angle offset and hull parameters are identified using an SQP (Sequential Quadratic Programming) algorithm. If the rudder angle offset is considered to be a fixed value, it is not possible to take into account changes in the ship's heading or the effects of disturbances that change from moment to moment.

[0008] As a result, when the rudder angle command used for identification requires a large change in course relative to the heading data, the hull parameters cannot be properly identified due to the constraint that the rudder angle offset is a fixed value. If the hull parameters take on inappropriate values, the control gains determined based on the hull parameters will also take inappropriate values. This causes the problem of unintended heading control responses.

[0009] Furthermore, in the ship's heading control device in Patent Document 1, a step-like course change is given to the ship's heading command value, and the rudder angle offset and hull parameters are identified using the rudder angle command and heading data at that time. For this reason, there is a problem in that it is not possible to identify the rudder angle offset and hull parameters for any steering pattern during normal navigation.

[0010] Furthermore, Patent Document 1 describes that a ship's heading control device performed good identification with a single step-like course change. It also describes that a control gain was calculated that would result in good course-changing characteristics. However, the number of course changes required and the course-changing pattern differ depending on the hull shape, load, ship speed, and course change amount. Patent Document 1 does not clearly state quantitative guidelines for what pattern of course-changing operation will result in good control gain being calculated.

[0011] The present application has been made to solve the above-mentioned problems, and aims to provide a heading control device and a heading control method that can calculate, while the ship is sailing, hull parameters for calculating appropriate control gains for any steering pattern while the ship is sailing, taking into account changes in the ship's sailing direction and the effects of disturbances that change from moment to moment. [Means for solving the problem]

[0012] The ship direction control device according to the present application comprises: a heading command generating unit that generates a heading command signal indicating the heading in which the vessel should proceed; a yaw angle detection unit that outputs a yaw angle signal that indicates a rotation angle around a vertical axis that passes through the center of gravity of the ship; a yaw angular velocity detection unit that outputs a yaw angular velocity signal that indicates a rotational angular velocity around a vertical axis passing through the center of gravity of the ship; a rudder angle detection unit that outputs a rudder angle signal indicating the angle of the rudder of the ship; a vessel speed detection unit that outputs a vessel speed signal indicating the vessel speed; a heading control unit that outputs a rudder angle command signal for directing the vessel in a desired heading direction based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a rudder angle control unit that controls the rudder based on the rudder angle command signal output by the azimuth control unit; The system includes a calculation feasibility determination unit that determines whether or not the frequency characteristics can be calculated based on the steering angle signal, the yaw angle signal, and the yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, a control gain adjustment unit that calculates the frequency characteristics of the yaw angle signal and the yaw angular velocity signal for the steering angle signal output by the steering angle detection unit and adjusts the control gain of the azimuth control unit.

[0013] The method for controlling the heading of a ship according to the present application further comprises: a step of generating a heading command signal indicating a heading in which the vessel should proceed by a heading command generating unit; a step of outputting a yaw angle signal indicating a rotation angle around a vertical axis passing through the center of gravity of the vessel by a yaw angle detection unit; a step of outputting a yaw angular velocity signal indicating a rotation angular velocity around a vertical axis passing through the center of gravity of the vessel by a yaw angular velocity detection unit; a step of outputting a rudder angle signal indicating the angle of the rudder of the vessel by a rudder angle detection unit; a step of outputting a rudder angle command signal by the heading control unit to direct the vessel in a desired heading based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a step of controlling the rudder by a rudder angle control unit based on the rudder angle command signal; The control gain adjustment unit has a step in which a calculation feasibility determination unit in the control gain adjustment unit determines whether the frequency characteristics can be calculated based on the steering angle signal, yaw angle signal, and yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, the control gain adjustment unit calculates the frequency characteristics of the yaw angle signal and yaw angular velocity signal with respect to the steering angle signal, and adjusts the control gain of the azimuth control unit. [Effects of the Invention]

[0014] The ship's heading control device and heading control method according to the present application can provide a heading control device and heading control method that can calculate hull parameters while sailing, taking into account changes in the sailing direction and the effects of external disturbances that change from moment to moment, in order to calculate appropriate control gains for any steering pattern while sailing. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a configuration diagram of a direction control device according to a first embodiment. [Figure 2] 1 is a hardware configuration diagram of a direction control device according to a first embodiment. [Figure 3] 1 is an explanatory diagram of a coordinate system of a ship on which a direction control device according to a first embodiment is installed. [Figure 4] 3 is a flowchart showing the basic operation of the direction control device according to the first embodiment. FIG. [Figure 5] 2 is a block diagram showing the configuration of a direction command generating unit of the direction control device according to the first embodiment. FIG. [Figure 6] 2 is a block diagram showing the configuration of a direction control unit of the direction control device according to the first embodiment. FIG. [Figure 7] 2 is a block diagram showing the configuration of a control calculation unit of the direction control device according to the first embodiment. FIG. [Figure 8] 2 is a block diagram showing the configuration of a control gain adjustment unit of the direction control device according to the first embodiment. FIG. [Figure 9] 4 is a diagram showing ship characteristic information of the direction control device according to the first embodiment. FIG. [Figure 10] 2 is a block diagram showing the configuration of a frequency characteristic calculation unit of the direction control device according to the first embodiment. FIG. [Figure 11] FIG. 10 is a configuration diagram of a direction control device according to a second embodiment. [Figure 12] FIG. 10 is a block diagram showing the configuration of a frequency characteristic calculation unit of a direction control device according to a second embodiment. [Figure 13] FIG. 10 is a configuration diagram of a direction control device according to a third embodiment. [Figure 14]FIG. 11 is a block diagram showing the configuration of a frequency characteristic calculation unit of a direction control device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, preferred embodiments of a vessel heading control device and a vessel heading control method will be described with reference to the drawings. In each embodiment, the same or equivalent parts are designated by the same reference numerals, and description thereof will be omitted.

[0017] 1. First Embodiment <Configuration of the heading control device> 1 shows an example of the configuration of a ship 1 equipped with a ship direction control device 10 according to embodiment 1. The direction control device 10 installed on the ship 1 receives operation information CI and various sensor information from an operation device 30 and a sensor group 20, and outputs a rudder angle drive command signal RUAD.

[0018] The heading control device 10 is composed of a heading command generation unit 100, a heading control unit 200, a control gain adjustment unit 500 consisting of a gain adjustment unit 300 and a frequency characteristic calculation unit 400, and a rudder angle control unit 600. The heading control device 10 inputs signals from each detection unit from the sensor group 20 and receives a heading command signal DRC to proceed from the heading command generation unit 100. It then outputs a rudder angle drive command signal RUAD to a rudder angle drive unit 40 to control the rudder angle. The rudder angle drive unit 40 operates the rudder in accordance with the rudder angle drive command signal RUAD. In this way, the heading control device 10 changes or maintains the heading of the ship 1 by outputting a heading command signal DRC to proceed.

[0019] In FIG. 1, the boat 1 is equipped with a propeller (not shown) for propelling the boat. The output of the propeller is controlled by an operating device 30. An outboard motor can be used as the propeller for the boat 1. An outboard motor has a screw integrally mounted below the engine as a propulsion and steering mechanism for the boat. The outboard motor is a propulsion device whose main body is attached to the outside of the hull. The heading of the outboard motor is controlled by changing the mounting angle of the outboard motor main body to the hull. Outboard motors are often used in small boats. A boat may be equipped with multiple outboard motors.

[0020] The application of the heading control device 10 according to the first embodiment is not limited to ships equipped with outboard motors. Large ships are often equipped with inboard motors. An inboard motor is a propulsion and steering mechanism in which a drive unit such as an engine is located inside the hull, a screw connected to the drive unit and with a variable rotation direction is exposed outside the ship, and the rudder is separate from the screw. The heading control device 10 according to the first embodiment can also be applied to ships equipped with a propulsion unit using an inboard motor.

[0021] There are also other ships equipped with inboard / outboard motors. An inboard / outboard motor is a propulsion and steering mechanism in which a drive unit such as an engine is located inside the ship, and a rudder and a screw connected to the drive unit outside the ship, whose rotation direction is variable, are integrated. The direction control device 10 according to the first embodiment can also be applied to ships equipped with inboard / outboard motors.

[0022] The operation device 30 is also used when the operator inputs the initial and terminal conditions for sailing the ship. The sensor group 20 is composed of, for example, a global navigation satellite system (hereinafter referred to as GNSS (Global Navigation Satellite System)) that measures the latitude and longitude of the ship 1 and a magnetic bearing sensor that measures the azimuth angle of the ship 1. The sensor group 20 may also include an inertial navigation system connected to a gyro that measures the angular velocity of the ship 1, an acceleration sensor that measures the translational acceleration of the ship 1, etc.

[0023] Specifically, the sensor group 20 includes a yaw angle detection unit 21 that outputs a yaw angle signal Y that indicates the angle of rotation around a vertical axis that passes through the center of gravity of the vessel 1. A yaw angular velocity detection unit 22 that outputs a yaw angular velocity signal YR that indicates the angular velocity of rotation around a vertical axis that passes through the center of gravity of the vessel 1 is also provided. A vessel speed detection unit 23 that outputs a vessel speed signal V that indicates the vessel speed of the vessel 1 is also provided.

[0024] Furthermore, a rudder angle detection unit 24 may be provided that outputs a rudder angle signal RUA that indicates the rudder angle of the vessel 1. Here, the yaw angular velocity detection unit 22 may be provided with a separate sensor for detecting angular velocity, or may be determined from a value obtained by time-differentiating the yaw angle signal Y that is the output of the yaw angle detection unit 21. The vessel speed detection unit 23 may determine the vessel speed from a screw tachometer, a water surface speed indicator, an airspeed indicator, an acceleration sensor, a GNSS, a radio wave or laser Doppler measurement device, or the like.

[0025] <Function of the directional control device> The heading control device 10 includes a heading command generation unit 100 that generates a heading command signal DRC that indicates the heading in which the ship should proceed. The heading control device 10 receives a yaw angle signal Y, a yaw angular velocity signal YR, a rudder angle signal RUA, and a ship speed signal V from a sensor group 20. The heading control device 10 receives operation information CI from an operation device 30.

[0026] In response to the heading command signal DRC generated by the heading command generation unit 100, the heading control unit 200 inputs the yaw angle signal Y, yaw angular velocity signal YR, and ship speed signal V, and outputs a rudder angle command signal RUAC with a control gain that achieves both stability and responsiveness. The rudder angle control unit 600 inputs the rudder angle command signal RUAC, generates a rudder angle drive command signal RUAD, and outputs it to the rudder angle drive unit 40 to control the rudder of the ship 1.

[0027] The direction control unit 200 outputs an instruction to acquire the frequency characteristics of the yaw angle signal Y and the yaw angular velocity signal YR relative to the rudder angle signal RUA of the ship 1 based on the operation information CI from the operation device 30. Specifically, a rectangular or sawtooth waveform rudder angle command signal RUAC is output, and the control gain adjustment unit 500 acquires the output data of the yaw angle signal Y and the yaw angular velocity signal YR in response to this.

[0028] The control gain adjustment unit 500 calculates frequency characteristics from the acquired output data and adjusts the control gain of the heading control unit 200 accordingly. This adjustment makes it possible to obtain a control gain that corresponds to fluctuations in the hull parameters of the ship 1, even if they vary due to changes in ship speed, draft, etc. As a result, heading control that achieves both stability and responsiveness can be achieved.

[0029] Here, we have described a case where an instruction to acquire the frequency characteristics of the yaw angle signal Y and the yaw angular velocity signal YR relative to the rudder angle signal RUA of the vessel 1 is given by the operation information CI from the operating device 30. However, when the heading control unit 200 detects that the vessel 1 is continuing to sail stably in the same heading, it may determine to acquire the frequency characteristics as needed and output a rectangular or sawtooth waveform rudder angle command signal RUAC. For example, the heading control unit 200 may perform the operation to acquire the frequency characteristics at predetermined time intervals or each time the heading control device 10 is started, cause the control gain adjustment unit 500 to calculate the frequency characteristics, and adjust the control gain of the heading control unit 200.

[0030] In addition to this, the control gain can also be adjusted when the vessel operator manually outputs a rudder angle command signal RUAC of any shape using a steering wheel, joystick, or the like without going through the heading control unit 200, or when the rudder angle command signal RUAC is output in response to a heading command signal DRC generated based on operation information CI from the operation device 30 during normal sailing. The rudder angle command signal RUAC generated using the yaw angle signal Y, yaw angular velocity signal YR, ship speed signal V, and control gain may be output in response to the heading command signal DRC, and the control gain adjuster 500 may obtain the output data of the yaw angle signal Y and yaw angular velocity signal YR in response to this, thereby adjusting the control gain of the heading control unit 200.

[0031] <Hardware configuration of the azimuth control device> FIG. 2 is a hardware configuration diagram of the direction control device 10. The hardware configuration in FIG. 2 can also be applied to the direction control devices 10a and 10b. The following describes the direction control device 10 as a representative example. In this embodiment, the direction control device 10 is an electronic control device that controls the direction of a ship. Each function of the direction control device 10 is realized by a processing circuit provided in the direction control device 10. Specifically, the direction control device 10 is provided with, as processing circuits, an arithmetic processing device 90 (computer) such as a CPU (Central Processing Unit), a storage device 91 that exchanges data with the arithmetic processing device 90, an input circuit 92 that inputs external signals to the arithmetic processing device 90, and an output circuit 93 that outputs signals from the arithmetic processing device 90 to the outside.

[0032] The arithmetic processing device 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, various signal processing circuits, etc. Furthermore, the arithmetic processing device 90 may include a plurality of the same or different types of devices, each performing a different process. The storage device 91 may include a RAM (Random Access Memory) configured to be able to read and write data from the arithmetic processing device 90, and a ROM (Read Only Memory) configured to be able to read data from the arithmetic processing device 90. The storage device 91 may include non-volatile or volatile semiconductor memory such as flash memory, EPROM, EEPROM, magnetic disk, flexible disk, optical disk, compact disk, minidisk, DVD, etc. The input circuit 92 is connected to the sensor group 20, various sensors including output signals from the operation device 30, switches, and communication lines, and includes an A / D converter, communication circuit, etc., for inputting the output signals of these sensors and switches and communication information to the arithmetic processing device 90. The output circuit 93 includes a drive circuit that outputs a control signal from the arithmetic processing unit 90 to a drive device including the steering angle drive unit 40 .

[0033] Each function of the direction control device 10 is realized by the arithmetic processing device 90 executing software (programs) stored in a storage device 91 such as a ROM, and working in cooperation with other hardware of the direction control device 10, such as the storage device 91, input circuit 92, and output circuit 93. Setting data such as thresholds and judgment values ​​used by the direction control device 10 is stored in the storage device 91 such as a ROM as part of the software (program). Each function of the direction control device 10 may be configured as a software module, or may be configured as a combination of software and hardware.

[0034] <Coordinate system and yaw angle> FIG. 3 is an explanatory diagram of the coordinate system of the ship 1 on which the direction control device 10 according to the first embodiment is installed. The coordinate system X1-Y1-Z1 indicates a coordinate system based on a fixed point on the ground or on the water at 0 m above sea level. The coordinate system X0-Y0-Z0 indicates a coordinate system based on the hull of the ship. These coordinate systems are right-handed. The position of a ship navigating on the water surface of the ocean, river, or lake on Earth is affected by the fact that it is on the surface of the Earth and is a sphere. However, if the distance between the ship 1 and a fixed point on the ground or on the water at 0 m above sea level and the ship 1 is small, the two can be considered to be on the same plane for simplicity.

[0035] In the coordinate system X1-Y1-Z1 of a fixed point on land or water at sea level, X1 indicates the north-south direction (the arrow indicates north), and Y1 indicates the east-west direction (the arrow indicates east). Z1 indicates the vertical direction (the arrow indicates down). Ship 1 exists on the X1-Y1 plane, and in the coordinate system X0-Y0-Z0 based on the hull, X0 indicates the fore-and-aft direction passing through the center of gravity of the hull (the arrow indicates the front, toward the bow), Y0 indicates the left-right direction passing through the center of gravity of the hull (the arrow indicates the right, toward starboard), and Z0 indicates the up-and-down direction of the hull structure passing through the center of gravity of the hull (the arrow indicates down).

[0036] The yaw angle YA (also called the azimuth angle) is the angle of rotation around the Z0 axis. The yaw angular velocity (yaw rate) is the angular velocity of rotation around the Z0 axis.

[0037] When the heading command generating unit 100 instructs the vessel to proceed in, the heading command signal DRC is expressed based on the X1 direction (north in FIG. 2) of the coordinate system X1-Y1-Z1 of a fixed point on land or water at sea level. The direction of the vessel 1's hull is expressed as a yaw angle based on the X1 direction. For example, when the vessel is instructed to proceed northeast, it navigates by maintaining a yaw angle YA of 45 degrees clockwise based on the X1 direction, which is north.

[0038] If the distance between ship 1 and a fixed point on the ground or water at sea level is large, the two cannot be simply considered to be on the same plane, and calculations must take into account that the Earth is a sphere. Even in this case, the ship still operates by maintaining a yaw angle indicated on the water surface where it is located, with north as the reference point.

[0039] <Flowchart showing basic operations> 4 is a flowchart showing the basic operation of the direction control device 10 according to embodiment 1. The direction control unit 200 adjusts the control gain by acquiring hull parameters in response to instructions from the operation device 30 or by its own judgment.

[0040] Since the reference transfer function is set in the initial state, the heading control unit 200 can calculate the rudder angle command signal RUAC based on the instruction of the heading command generation unit 100 without performing any adjustment. However, by acquiring the frequency characteristics of the yaw angle signal Y and the yaw angular velocity signal YR with respect to the rudder angle signal RUA of the ship 1, the control gain of the heading control unit 200 can be adjusted in accordance with the latest state of the ship 1.

[0041] The flowchart in Figure 4 is executed each time the heading control device 10 adjusts the control gains by acquiring hull parameters. In step S100, while the ship is sailing, the heading control unit 200 outputs a rectangular or sawtooth wave rudder angle command signal RUAC, a rudder angle command of any shape manually generated by the operator using a steering wheel or the like, or a rudder angle command calculated by the heading control unit 200 based on the heading command signal DRC during normal sailing.

[0042] In step S101, the frequency characteristic calculation unit 400 acquires time series data of the yaw angle signal Y and the yaw angular velocity signal YR relative to the rudder angle signal RUA. The frequency characteristic calculation unit 400 calculates frequency characteristics as vessel characteristic information FC. At this time, data of the vessel speed signal V may also be acquired at the same time to calculate frequency characteristics according to the vessel speed.

[0043] In step S103, the target response performance information TC is read out. The target response performance information TC is determined in advance for the vessel 1, and a basic reference transfer function is set from the target response performance information TC.

[0044] In step S104, the frequency characteristics (vessel characteristic information FC) calculated in step S101 are used to calculate control gain information GI based on a reference transfer function set from the target response performance information TC. In step S105, the control gain information GI is used to execute a heading control calculation in the heading control unit 200, and a rudder angle command signal RUAC is output. A rudder angle drive command signal RUAD is output from the rudder angle control unit 600 in accordance with the rudder angle command signal RUAC, and the rudder angle drive unit 40 is controlled, thereby controlling the heading of the vessel 1. At this time, data on the vessel speed signal V may be simultaneously acquired in steps S101 to S105, and the control gain information GI corresponding to the vessel speed may be calculated.

[0045] The functions of the heading command generating unit 100, heading control unit 200, gain adjusting unit 300, and frequency characteristic calculating unit 400 that constitute the ship's heading control device 10 will be described in detail.

[0046] <Direction command generator> 5 is a block diagram showing the configuration of the heading command generation unit 100 of the heading control device 10 according to embodiment 1. The heading command generation unit 100 is made up of a motion condition setting unit 101 and a heading calculation unit 102. The motion condition setting unit 101 sets the initial conditions and terminal conditions for the navigation of the ship 1, and is set by operation information CI input by the operator to the operation device 30 of the ship 1.

[0047] The operator uses the operating device 30 of the vessel 1 to set information on the attitude angle (synonymous with azimuth angle or yaw angle), angular velocity (single time derivative of the attitude angle), and angular acceleration (double time derivative of the attitude angle) for the initial state before the start of navigation and the final state at the completion of the desired navigation. This condition setting may be given as numerical values ​​of the attitude angle, angular velocity, and angular acceleration. It may also be set using a GNSS touch panel user interface. The initial state may be set by automatically capturing the detection values ​​of the sensor group 20 as sensor group information, and only the final state being set by touch input on the user interface screen.

[0048] The heading calculation unit 102 receives the initial state information SCI and the terminal state information ECI output by the motion condition setting unit 101 and calculates a heading command signal DRC. There are several possible methods for calculating the heading command signal DRC. For example, it is possible to calculate a trajectory given as a polynomial of time based on the attitude angle, angular velocity, and angular acceleration in the initial state information SCI and terminal state information ECI of the ship 1 obtained by the motion condition setting unit 101.

[0049] It is also possible to calculate a straight-line trajectory that connects the initial state information SCI and the final state information ECI in the shortest time. It is also possible to calculate a trajectory that can be reached between the initial state and the final state with the least amount of fuel. That is, when transitioning from the initial state to the final state, it is possible to calculate an optimal trajectory that minimizes a preset evaluation function, for example, an optimal trajectory in terms of the shortest time or the least amount of fuel.

[0050] <Orientation control unit> 6 is a block diagram showing the configuration of the heading control unit 200 of the heading control device 10 according to embodiment 1. The heading control unit 200 is made up of a control calculation unit 210 and a sensor information processing unit 220. The sensor information processing unit 220 outputs the yaw angle signal Y and the yaw angular velocity signal YR, which are the outputs of the sensor group 20, to the control calculation unit 210. At this time, data on the boat speed signal V may also be acquired and output to the control calculation unit 210.

[0051] The sensor information processing unit 220 may have a function of converting the information of the various sensors sent from the sensor group 20 from a serial signal to a parallel signal, and may also have a function of generating a yaw angular velocity signal YR by time-differentiating the yaw angle signal Y.

[0052] The control calculation unit 210 outputs a rudder angle command signal RUAC to the rudder angle control unit 600 based on the azimuth command signal DRC output from the azimuth command generation unit 100, the control gain information GI (GI1, GI2, GI3) output from the gain adjustment unit 300, and the yaw angle signal Y and yaw angular velocity signal YR output from the sensor information processing unit 220. At this time, the control gain may be switched in accordance with the data of the boat speed signal V, and the rudder angle command signal RUAC may be calculated and output.

[0053] <Control and calculation section> 7 is a block diagram showing the configuration of the control calculation unit 210 of the direction control device 10 according to Embodiment 1. The control calculation unit 210 includes a first control calculation unit 211, a second control calculation unit 212, a third control calculation unit 213, and an adder 214.

[0054] The first control calculation unit 211 calculates and outputs a yaw angular velocity command signal YRC by known P (Proportional) control using first control gain information GI1 so as to zero the deviation between DRC and the yaw angle signal Y. The second control calculation unit 212 calculates and outputs an FB (Feedback) steering angle command FBC by known PI (Proportional Integral) control using second control gain information GI2 so as to zero the yaw angular velocity deviation between the yaw angular velocity command signal YRC and the yaw angular velocity signal YR, which are outputs of the first control calculation unit 211.

[0055] The third control calculation unit 213 calculates and outputs a FF (Feedforward) steering angle command FFC based on the yaw angular velocity command signal YRC and third control gain information GI3 that are outputs of the first control calculation unit 211. The adder 214 adds the FF steering angle command FFC that is the output of the third control calculation unit 213 to the FB steering angle command FBC that is the output of the second control calculation unit 212.

[0056] The adder 214 outputs the rudder angle command signal RUAC as the result of the addition. By configuring the control calculation unit 210 in this way, the first and second control calculation units 211, 212 can improve heading stability, and the third control calculation unit 213 can improve heading responsiveness. Furthermore, the first control calculation unit 211, second control calculation unit 212, and third control calculation unit 213 may simultaneously switch control gains in accordance with the data of the boat speed signal V and output the result.

[0057] <Control gain adjustment section> 8 is a block diagram showing the configuration of the gain adjustment unit 300 of the azimuth control device 10 according to the first embodiment. The azimuth movement of the ship 1 can generally be characterized as the frequency characteristic of the yaw angular velocity signal YR relative to the rudder angle signal RUA. For example, in Patent Document 1, a first-order model is used as the frequency characteristic of the yaw angular velocity signal YR relative to the rudder angle signal RUA.

[0058] However, the frequency characteristics of the ship 1 vary greatly depending on the motion state of the ship 1, for example, the speed of the ship (hereinafter referred to as ship speed), and for example, when the rudder angle is turned by a predetermined amount at a predetermined speed, the yaw angular velocity signal YR tends to be small in a low ship speed range and large in a high ship speed range. Therefore, in order to reduce the variation in control response due to ship speed while keeping the crossover frequency that determines the response of the control system constant regardless of ship speed, it is necessary to make the control gain information input to the control calculation unit 210 variable depending on the ship speed.

[0059] FIG. 9 is a diagram showing ship characteristic information of the heading control device 10 according to the first embodiment. Here, the frequency characteristics of the yaw angular velocity signal YR relative to the rudder angle signal RUA are shown in terms of gain and phase. In the low-speed range (shown by the solid line) where the ship speed is low, the characteristics are relatively easy to approximate with a first-order model. However, in the high-speed range (shown by the dashed line) where the ship speed is high, the gain increases and, depending on the conditions, the shape exhibits a gentle peak gain on the high-frequency side, making it impossible to approximate with a first-order model. While FIG. 9 shows the frequency characteristics of the yaw angular velocity signal YR, the same can be said for the yaw angle signal Y.

[0060] In order to appropriately design or set the control gain information GI in the control calculation unit 210 in accordance with the ship speed, the gain adjustment unit 300 calculates and outputs the control gain information GI based on the ship characteristic information and target response performance information TC that are output from the frequency characteristic calculation unit 400, which will be described later. The gain adjustment unit 300 shown in FIG. 8 is made up of a reference transfer function setting unit 301 and an online gain adjustment unit 302.

[0061] The reference transfer function setting unit 301 outputs a reference transfer function that represents the frequency characteristic of the yaw angle signal Y with respect to the steering angle signal RUA that achieves the target response performance, and a reference transfer function that represents the frequency characteristic of the yaw angular velocity signal YR with respect to the steering angle signal RUA, based on arbitrarily selected target response performance information TC, for example, a gain crossover frequency.The online gain adjustment unit 302 then calculates and outputs control gain information GI (GI1, GI2, GI3) related to the first to third control calculation units (211 to 213) in the control calculation unit 210 described above.

[0062] The online gain adjustment unit 302 calculates the control gain information GI1, GI2 related to the first and second control calculation units 211, 212 based on the ship characteristic information FC, which is the output of the frequency characteristic calculation unit 400 described later, and the reference transfer function, which is the output of the reference transfer function setting unit 301, for example, by a known partial model matching method.

[0063] On the other hand, the control gain information GI3 related to the third control calculation unit 213 is calculated based on the ship characteristic information, for example, by using the frequency characteristics of the rudder angle signal RUA relative to the yaw angular velocity signal YR, which is an inverse model of the frequency characteristics of the yaw angular velocity signal YR relative to the rudder angle signal RUA. In this case, if the inverse model includes a high order, for example, two time derivatives, a low-pass filter or moving average processing may be provided after the inverse model to suppress abrupt changes in the FF rudder angle command FFC, which is the output of the third control calculation unit 213. Also, an approximation process may be introduced to reduce the order of the inverse model itself.

[0064] At the same time, data on the boat speed signal V may be added as an input to the gain adjustment unit 300 in FIG. 8, and a control gain according to the boat speed may be determined.

[0065] <Frequency characteristic calculation section> 10 is a block diagram showing the configuration of the frequency characteristic calculation unit 400 of the direction control device 10 according to Embodiment 1. The frequency characteristic calculation unit 400 inputs ship characteristic information FC to the gain adjustment unit 300. The frequency characteristic of the azimuth movement of the ship 1 generally changes depending on the ship speed.

[0066] One possible method for determining this frequency characteristic is to use the amplification factor and phase difference of the response of the rudder angle signal RUA and the yaw rate signal YR when a sinusoidal rudder angle command signal RUAC is applied while sweeping the frequency while the ship 1 is sailing at a constant speed. However, this method requires a huge amount of measurement time and storage capacity to obtain characteristics at low frequencies, and is therefore unsuitable for online estimation of the ship characteristic information FC that characterizes the above frequency characteristics.

[0067] In contrast, the frequency characteristic calculation unit 400 receives as input the sensor group information, which is the output of the sensors 20 when a rectangular or sawtooth waveform signal having sufficient power in a bandwidth of interest in the frequency characteristics is applied for a predetermined period of time as a rudder angle command signal RUAC, and estimates and outputs the vessel characteristic information online. The frequency characteristic calculation unit 400 is made up of a data processing unit 401 and a recursive estimation filter unit 402.

[0068] The data processing unit 401 is a filter that removes observation noise superimposed on the rudder angle signal RUA, yaw angular velocity signal YR, and boat speed signal V based on the sensor group information output from the sensor group 20. The output of the data processing unit 401 is processed data such as the rudder angle signal RUA, yaw angular velocity signal YR, and boat speed signal V.

[0069] <Calculation Approval Determination Department> The calculation feasibility determination unit 403 determines whether the obtained data is appropriate for calculating the frequency characteristics by calculating the magnitude or degree of correlation between the steering angle signal RUA, the yaw angular velocity signal YR, and the yaw angle signal Y based on the sensor group information, which is the output of the sensor group 20. Then, the calculation feasibility determination unit 403 outputs determination information PC.

[0070] The conditions for data to be suitable for calculating frequency characteristics may include a sufficiently high signal-to-noise ratio, which is the ratio of the sensor signal to sensor noise, and a small fluctuation due to irregular disturbances such as waves compared to the magnitude of the sensor signal. A method for determining whether data is suitable for calculating frequency characteristics may be whether the magnitude (absolute value) of the steering angle signal or steering angle command signal, or the magnitude (absolute value) of the steering angular velocity signal or steering angular velocity command signal, which is their difference, exceeds a threshold. Another condition may be whether the value of the correlation coefficient sequentially calculated from the steering angle signal or steering angular velocity signal and the yaw angular velocity signal exceeds a threshold.

[0071] The threshold value may also be changed depending on the ship speed. Generally, the slower the ship speed, the lower the signal-to-noise ratio, and the greater the impact of rocking due to disturbances such as waves. For this reason, when the ship speed is low, the threshold value may be increased to relax the criteria for determining whether the calculation is possible. When using a rudder angle or rudder angular velocity signal as a method for selecting the threshold value, an empirical value that is considered to result in a sufficiently large yaw angular velocity can be used. When using a correlation coefficient, a value between 0.7 and 1 may be used.

[0072] The recursive estimation filter unit 402 outputs vessel characteristic information candidate RFC and estimation accuracy information PR of the vessel characteristic information candidate RFC based on the processed data output from the data processing unit 401 and the determination information PC output from the calculation feasibility determination unit 403. For example, the recursive estimation filter unit 402 recursively estimates a frequency characteristic model of the yaw angular rate signal YR relative to the rudder angle signal RUA using the well-known recursive least squares method, and outputs the result as the vessel characteristic information candidate RFC. In addition, in the process of estimating the frequency characteristic model, the variance and prediction error amount of the estimated value of the model can be simultaneously obtained. The variance or prediction error amount is output as estimation accuracy information PR.

[0073] As mentioned above, in high-speed ranges where the ship speed is high, peak gains may occur on the high-frequency side. Therefore, to accommodate high-speed ranges where peak gains occur, the order of the frequency characteristic model is set to second or higher, and a frequency characteristic model of the yaw angular velocity signal YR relative to the rudder angle signal RUA is sequentially estimated. A frequency characteristic model may also be estimated in a similar manner for the frequency characteristics of the yaw angle signal Y relative to the rudder angle signal RUA.

[0074] <Steering angle offset amount> When a ship is sailing straight ahead while being subjected to disturbances from the lateral direction of the ship, such as currents and wind, it is necessary to maintain the rudder angle at a specified angle. This rudder angle is called the rudder angle offset amount RUA0. When the rudder angle offset amount RUA0 is large, the frequency characteristic model that represents the dynamic characteristics of the ship cannot adequately express the ship's behavior. Therefore, an example of an ARX (Auto-Regressive eXogenous) model that takes into account the rudder angle offset amount RUA0 is expressed by the following difference equation.

[0075] YR[k]=A1×YR[k-1]+A2×YR[k-2] +B1×(U[k-1]-U0)+B2×(U[k-2]-U0) *A1, A2, B1, and B2 are parameters that represent the dynamic characteristics of the ship, U0 is the rudder angle offset, YR is the yaw angular velocity, U is the rudder angle, and K, K-1, and K-2 are data sample numbers.

[0076] This model can express that when there is a disturbance from the hull's lateral direction and the rudder angle offset amount U0 is not zero, the yaw angular velocity YR will converge to different values ​​when the rudder angle U is set to a constant value of 10 degrees and when the rudder angle U is set to a constant value of -10 degrees. Therefore, by using a model that explicitly takes the rudder angle offset amount into consideration, the rudder angle offset amount can be estimated.

[0077] For example, the parameters A1, A2, B1, and B2 representing dynamic characteristics and the rudder angle offset amount U0 representing static characteristics can be sequentially estimated by the well-known recursive least squares method. Furthermore, because the rudder angle offset amount U0 can be sequentially estimated, even if the heading changes significantly while navigating, changing the direction of the disturbances the hull receives, or even if the strength of the disturbances increases or decreases, the parameters A1, A2, B1, and B2 and the rudder angle offset amount U0 can be appropriately sequentially estimated.

[0078] The model used in the recursive estimation filter unit 402 is not limited to the second-order ARX model described above. For example, various models such as a first-order ARX model, a differential equation model, or a state space model can be used to output the ship characteristic information candidate RFC and the estimation accuracy information PR.

[0079] Furthermore, the estimation method used in this recursive estimation filter unit 402 is not limited to the recursive least squares method described above. Various other recursive estimation methods, such as a well-known Kalman filter, an extended Kalman filter, a Kalman smoother, and a recursive subspace identification method, can be used to obtain the ship characteristic information candidate RFC. Furthermore, the well-known recursive estimation methods mentioned above can also estimate the variance and prediction error of the estimated value, and can therefore output these as estimation accuracy information PR.

[0080] Furthermore, based on the determination information PC output by the calculation feasibility determination unit 403, part or all of the calculation algorithm of the sequential estimation method can be stopped or changed, and the vessel characteristic information candidate RFC can be calculated sequentially using only data suitable for the calculation. For example, if the rudder angle is hardly changed, it may not be possible to properly estimate the parameters representing the dynamic characteristics, and an inappropriate vessel characteristic information candidate RFC may be calculated.

[0081] However, this function makes it possible to extract only the data that can appropriately estimate the parameters that represent dynamic characteristics. As a result, it is possible to calculate an appropriate candidate ship characteristic information RFC. In addition, by providing a forgetting function for some variables in the calculation algorithm when the calculation algorithm is stopped or changed, it is possible to resume estimation without being influenced by the previous estimated information even if the stop or change period is long.

[0082] This function makes it possible to appropriately calculate the vessel characteristic information candidate RFC without applying a rectangular or sawtooth waveform rudder angle command signal RUAC, which is considered suitable for estimating dynamic characteristics.Even if a rudder angle command signal RUAC manually generated by the vessel operator or a rudder angle command signal RUAC calculated by the heading control unit 200 based on the heading command signal DRC during normal navigation is used, only data suitable for calculation can be automatically extracted to calculate the vessel characteristic information candidate RFC.As a result, an appropriate vessel characteristic information candidate RFC can be calculated.

[0083] <Characteristics Learning Section> The characteristic learning unit 404 learns the vessel characteristic information candidate RFC at the time when the estimation accuracy information PR is good based on the vessel characteristic information candidate RFC and estimation accuracy information PR output from the sequential estimation filter unit 402, and outputs it as vessel characteristic information FC. The vessel characteristic information FC is learned each time the estimation accuracy information PR exceeds a predetermined threshold. Furthermore, by leaving the vessel characteristic information FC at a default value (initial setting value) from the start of calculation of the vessel characteristic information candidate RFC until the estimation accuracy information PR exceeds the threshold, it is possible to prevent low-accuracy vessel characteristic information FC from being output.

[0084] Furthermore, the learning of the vessel characteristic information FC by the vessel characteristic information candidate RFC by the characteristic learning unit 404 may be performed by using an averaging method involving a first-order lag element to reflect the vessel characteristic information candidate RFC in the vessel characteristic information FC. For example, this may be calculated using the following formula:

[0085] FC(n)=K×RFC+(1-K)×FC(n-1) *K is a reflection coefficient between 0 and 1, FC(n) is the ship characteristic information calculated this time, and FC(n-1) is the ship characteristic information calculated last time.

[0086] Furthermore, the learning by the characteristic learning unit 404 may change the reflection ratio of the vessel characteristic information candidate RFC depending on the value of the estimation accuracy information PR. For example, the value of the reflection coefficient K may be set to increase as the value of the estimation accuracy information PR increases.

[0087] Here, by linking the estimated frequency characteristic model to the ship speed, which is the output of the data processing unit 401, the ship characteristic information FC can be stored in the characteristics learning unit 404 as a function or map of the ship speed. Storing the ship characteristic information FC in the characteristics learning unit 404 makes it possible to respond immediately to changes in the ship speed or changes in the target response performance information TC. Without having to re-estimate the frequency characteristics, the control gain information GI can be appropriately designed or set based on the ship characteristic information FC stored in the characteristics learning unit 404.

[0088] Furthermore, the vessel characteristic information FC learned by the characteristic learning unit 404 may have learned values ​​divided into multiple sections according to the yaw angle signal Y, the yaw angular velocity signal YR, the rudder angle signal RUA, etc. By finely setting multiple learned values ​​in this manner, it is possible to use optimal target response performance information TC according to the yaw angle signal Y, the yaw angular velocity signal YR, the rudder angle signal RUA, etc.

[0089] As described above, the heading control device 10 for a ship that causes the ship 1 to sail in a desired heading according to Embodiment 1 has been described. The heading control device 10 includes a heading command generation unit 100 that outputs a heading command signal DRC, a frequency characteristic calculation unit 400 that receives sensor group information from a sensor group 20 mounted on the ship and outputs ship characteristic information FC, and a gain adjustment unit 300 that outputs control gain information GI based on the ship characteristic information FC output by the frequency characteristic calculation unit 400. The heading control unit 200 outputs a rudder angle command signal RUAC based on the heading command signal DRC output by the heading command generation unit 100, the control gain information GI from the gain adjustment unit 300, and the sensor group information from the sensor group 20.

[0090] This allows the ship's hull parameters to be calculated while the ship is underway, taking into account changes in heading and the effects of disturbances that change from moment to moment, in order to calculate control gains that will provide good course-changing characteristics for any steering pattern during normal navigation. This allows appropriate control gains to be calculated instantly in response to modeling errors that may change in the controlled object. As a result, a robust design is possible against changes in the characteristics of the controlled object, and disturbance suppression performance and target value response performance related to heading control can be appropriately adjusted. Furthermore, stable heading control can be achieved without increasing vibrations excited by disturbance factors on the ship, such as tidal currents, waves, wind, and rain.

[0091] 2. Second Embodiment Fig. 11 is a configuration diagram of a direction control device 10a according to embodiment 2. Fig. 12 is a block diagram showing the configuration of a frequency characteristic calculation unit 400a of the direction control device 10a according to embodiment 2.

[0092] The direction control device 10a according to the second embodiment of Fig. 11 differs from the direction control device 10 according to the first embodiment in that the steering angle drive command signal RUAD input to the steering angle drive section 40 is output by a steering angle control section 600a that receives as input the steering angle offset amount RUA0 output by a frequency characteristic calculation section 400a provided in a control gain adjustment section 500a and the steering angle command signal RUAC output by the direction control section 200. The other configuration is the same as in Fig. 1, so the same reference numerals are used and their explanations are omitted.

[0093] Fig. 12 is a block diagram showing the configuration of a frequency characteristic calculation unit 400a of a direction control device 10a according to the second embodiment. The frequency characteristic calculation unit 400a is made up of a data processing unit 401, a recursive estimation filter unit 402a, a calculation feasibility determination unit 403, and a characteristic learning unit 404. In the first embodiment, the output of the recursive estimation filter unit 402 was the vessel characteristic information candidate RFC. In contrast, in the second embodiment, the estimated rudder angle offset amount RUA0 is output together with the vessel characteristic information candidate RFC to a rudder angle control unit 600a. The rudder angle control unit 600a outputs a rudder angle drive command signal RUAD that takes into account the rudder angle offset amount RUA0 to perform direction control.

[0094] With this configuration, it is possible to output a steering angle drive command signal RUAD that offsets the disturbance caused by the steering angle offset amount RUA0, thereby suppressing the deterioration of responsiveness and stability caused by the disturbance caused by the steering angle offset amount RUA0, and improving the heading control performance.

[0095] 3. Embodiment 3 Fig. 13 is a configuration diagram of a direction control device 10b according to embodiment 3. Fig. 14 is a block diagram showing the configuration of a frequency characteristic calculation unit 400b of the direction control device 10b according to embodiment 3.

[0096] The direction control device 10b according to the third embodiment in Fig. 13 differs from the direction control device 10a according to the second embodiment in that the frequency characteristic calculation unit 400b provided in the control gain adjustment unit 500b is different. The frequency characteristic calculation unit 400b according to the third embodiment in Fig. 14 differs from the frequency characteristic calculation unit 400a according to the second embodiment in that the steering angle offset amount RUA0 output by the recursive estimation filter unit 402a is input to the calculation feasibility determination unit 403a and reflected in the determination information PC. The other configurations described above are the same as those in Figs. 11 and 12 according to the second embodiment, so the same reference numerals are used and description thereof will be omitted.

[0097] In the first and second embodiments, the calculation feasibility determination unit 403 calculates absolute values ​​or correlation coefficients of the rudder angle signal RUA, yaw angle signal Y, yaw angular velocity signal YR, etc., and outputs the determination information. In contrast, in the third embodiment, the determination information is output using a signal in which the rudder angle offset amount RUA0 is further superimposed on the rudder angle signal RUA. This makes it possible to more accurately determine the correlation between the yaw angle signal Y, yaw angular velocity signal YR, etc., used for the determination in the calculation feasibility determination unit 403. With this configuration, even when the rudder angle offset amount RUA0 is large, it becomes possible to extract data more appropriate for estimating dynamic characteristics, and it is possible to output more accurate vessel characteristic information candidate RFC.

[0098] In the above-described first, second and third embodiments, the azimuth command generating unit 100, azimuth control unit 200, gain adjusting unit 300, frequency characteristic calculating units 400, 400a and 400b, and steering angle control units 600, 600a of the azimuth control devices 10, 10a and 10b shown in Fig. 1, as well as the control blocks comprising the functions shown in Figs. 4 to 8 and 10 to 14, may be configured as separate control circuits, or may be configured as a single control circuit.

[0099] Furthermore, the control block may also be integrated to include a rudder angle drive mechanism that controls the rudder angle of the outboard motor and the inboard motor. The processing circuitry that realizes these functions may be dedicated hardware. These functions may also be configured using a CPU (also called a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP) that executes programs stored in memory.

[0100] When the control parts of the ship direction control devices 10, 10a, and 10b according to the first, second, and third embodiments are configured with software, the functions of the control parts of the respective embodiments may be implemented by software that is downloaded to memory and executed each time the software is executed. Alternatively, these may be implemented by firmware fixed in a non-volatile storage device of a computer, or by a combination of the aforementioned types of software and firmware.

[0101] The aforementioned types of software and firmware are written as programs and stored in memory. A processor, which is a processing circuit, realizes the functions of each part by reading and executing the programs stored in memory. These programs cause the computer to execute the procedures and methods of each part. Here, memory refers to, for example, non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, magnetic disks, flexible disks, optical disks, compact disks, minidisks, DVDs, etc.

[0102] Furthermore, some of the functions of the control blocks described above may be implemented by dedicated hardware, and some by the aforementioned types of software or firmware. In this way, the processing circuit of each embodiment can implement each function by hardware, the aforementioned types of software, firmware, or a combination of these. Furthermore, various information required for processing is preset in the circuit in the case of a hardware configuration, or is stored in memory in advance in the case of a software configuration.

[0103] In all of the above-described embodiments, the control and calculation unit may be configured with only an angle major loop, a double loop consisting of an angle major loop and an angular velocity minor loop, or a triple loop consisting of an angle major loop, an angular velocity minor loop, and an angular acceleration minor loop. In this case, the angular acceleration may be obtained by twice differentiating the yaw angle signal Y, which is one of the sensor group information, with respect to time, or by once differentiating the yaw angular velocity signal YR with respect to time. Furthermore, in all of the embodiments, the controller may be configured in a manner that is not only a classical control system, but also a modern control system for state feedback control.

[0104] Although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0105] Various aspects of the present disclosure are summarized below as appendices.

[0106] (Appendix 1) a heading command generating unit that generates a heading command signal indicating the heading in which the vessel should proceed; a yaw angle detection unit that outputs a yaw angle signal indicating a rotation angle around a vertical axis passing through the center of gravity of the vessel; a yaw angular velocity detection unit that outputs a yaw angular velocity signal that indicates a rotational angular velocity around a vertical axis passing through the center of gravity of the vessel; a rudder angle detection unit that outputs a rudder angle signal indicating the angle of the rudder of the ship; a vessel speed detection unit that outputs a vessel speed signal indicating the vessel speed; a heading control unit that outputs a rudder angle command signal for directing the vessel toward the desired heading, based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a rudder angle control unit that controls the rudder based on the rudder angle command signal output by the azimuth control unit; a calculation feasibility determination unit that determines whether frequency characteristics can be calculated based on the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, a control gain adjustment unit that calculates each of the frequency characteristics of the yaw angle signal and the yaw angular velocity signal with respect to the rudder angle signal output by the rudder angle detection unit and adjusts a control gain of the directional control unit. (Appendix 2) 2. The ship direction control device according to claim 1, wherein the calculation feasibility determination unit of the control gain adjustment unit determines whether the frequency characteristics can be calculated based on at least one of the degree of correlation, amplitude, amount of change, signal-to-noise ratio, and fluctuation ratio due to disturbance of the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal. (Appendix 3) 3. The vessel heading control device according to claim 2, wherein the calculation feasibility determination unit of the control gain adjustment unit changes a comparison threshold value, which determines whether the frequency characteristics can be calculated or not, based on at least one of the degree of correlation, amplitude, amount of change, signal-to-noise ratio, and rate of fluctuation due to disturbance of the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, in accordance with the vessel speed signal. (Appendix 4) 4. A ship direction control device according to claim 1, wherein the calculation feasibility determination unit of the control gain adjustment unit allows the calculation of the frequency characteristics when the amount of change in the rudder angle signal is greater than a predetermined amount of change. (Appendix 5) 5. A ship heading control device according to claim 1, wherein the control gain adjustment unit calculates a calculation accuracy when calculating the frequency characteristics of the yaw angle signal and the yaw angular velocity signal relative to the rudder angle signal, and adjusts the control gain of the heading control unit based on the calculated frequency characteristics when the calculation accuracy is higher than a predetermined accuracy. (Appendix 6) 6. The vessel heading control device according to claim 5, wherein the control gain adjuster learns the calculated frequency characteristics when the calculation accuracy is higher than a predetermined accuracy. (Appendix 7) 7. The vessel heading control device according to claim 6, wherein the control gain adjustment unit performs learning by weighting the calculated frequency characteristics in accordance with the calculation accuracy. (Appendix 8) 8. A vessel heading control device according to claim 1, wherein the control gain adjustment unit calculates a rudder angle offset amount, which is a rudder angle when the vessel is sailing straight ahead, and adjusts the control gain of the heading control unit. (Appendix 9) 9. The vessel heading control device according to claim 8, wherein the control gain adjuster calculates the rudder angle offset amount by a difference equation based on a model in which the rudder angle offset amount is explicitly expressed. (Appendix 10) 10. A vessel direction control device according to claim 8, wherein the rudder angle control unit controls the rudder based on the rudder angle command signal and the rudder angle offset amount. (Appendix 11) 11. The vessel direction control device according to claim 8, wherein the calculation feasibility determination unit of the control gain adjustment unit determines whether the frequency characteristic can be calculated based on the rudder angle signal and the rudder angle offset amount. (Appendix 12) The direction control unit a first control calculation unit that calculates a yaw angular velocity command signal that makes the deviation between the azimuth command signal and the yaw angle signal zero; a second control calculation unit that calculates a feedback steering angle command signal such that a deviation between the yaw angular velocity command signal calculated by the first control calculation unit and the yaw angular velocity signal becomes zero; a third control calculation unit that calculates a feedforward steering angle command signal based on the yaw angular velocity command signal; 12. A ship heading control device according to claim 1, further comprising an adder that adds the feedback rudder angle command signal calculated by the second control calculation unit and the feedforward rudder angle command signal calculated by the third control calculation unit to output a rudder angle command signal. (Appendix 13) The control gain adjustment unit a reference transfer function setting unit that sets, for the steering angle signal, a yaw angle signal reference transfer function having a frequency characteristic to be targeted for the yaw angle signal, and a yaw angular velocity signal reference transfer function having a frequency characteristic to be targeted for the yaw angular velocity signal; 13. A ship heading control device according to claim 1, further comprising an online gain adjustment unit that adjusts a control gain of the heading control unit based on the yaw angle signal reference transfer function and the yaw angular velocity signal reference transfer function set by the reference transfer function setting unit. (Appendix 14) a step of generating a heading command signal indicating a heading in which the vessel should proceed by a heading command generating unit; a step of outputting a yaw angle signal indicating a rotation angle around a vertical axis passing through the center of gravity of the vessel by a yaw angle detection unit; a step of outputting a yaw angular velocity signal indicating a rotation angular velocity around a vertical axis passing through the center of gravity of the vessel by a yaw angular velocity detection unit; a step of outputting a rudder angle signal indicating the angle of the rudder of the vessel by a rudder angle detection unit; a step of outputting a rudder angle command signal by the heading control unit to direct the vessel in a desired heading based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a step of controlling the rudder by a rudder angle control unit based on the rudder angle command signal; a calculation feasibility determination unit included in a control gain adjustment unit determines whether frequency characteristics can be calculated based on the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, the control gain adjustment unit calculates each of the frequency characteristics of the yaw angle signal and the yaw angular velocity signal with respect to the rudder angle signal, and adjusts a control gain of the azimuth control unit. (Appendix 15) The step of outputting the steering angle command signal by the direction control unit includes: a step of calculating, by a first control calculation unit, a yaw angular velocity command signal that makes the deviation between the azimuth command signal and the yaw angle signal zero; a step of calculating, by a second control calculation unit, a feedback steering angle command signal that sets a deviation between the yaw angular velocity command signal calculated by the first control calculation unit and the yaw angular velocity signal to zero; a step of calculating a feedforward steering angle command signal based on the yaw angular velocity command signal by a third control calculation unit; a step of adding, by an adder, the feedback rudder angle command signal calculated by the second control calculation unit and the feedforward rudder angle command signal calculated by the third control calculation unit, and outputting a rudder angle command signal. [Explanation of symbols]

[0107] 1 ship, 10, 10a, 10b heading control device, 20 sensor group, 21 yaw angle detection unit, 22 yaw angular velocity detection unit, 23 ship speed detection unit, 24 rudder angle detection unit, 30 operation device, 40 rudder angle drive unit, 100 heading command generation unit, 200 heading control unit, 210 control calculation unit, 211 first control calculation unit, 212 second control calculation unit, 213 third control calculation unit, 214 adder, 220 sensor information processing unit, 300 gain adjustment unit, 301 reference transfer function setting unit, 302 online gain adjustment unit, 400, 400a, 400b frequency characteristic calculation unit, 401 data processing unit, 402, 402a sequential estimation filter unit, 403, 403a calculation feasibility determination unit, 500, 500a, 500b Control gain adjustment unit, 600, 600a rudder angle control unit, CI operation information, DRC heading command signal, ECI terminal state information, FBC FB rudder angle command, FC ship characteristic information, FFC FF rudder angle command, GI1 first control gain information, GI2 second control gain information, GI3 third control gain information, GI control gain information, PC judgment information, PR estimation accuracy information, RFC ship characteristic information candidate, RUA rudder angle signal, RUA0 rudder angle offset amount, RUAC rudder angle command signal, RUAD rudder angle drive command signal, SCI initial state information, TC target response performance information, V ship speed signal, Y yaw angle signal, YA yaw angle, YR yaw angular velocity signal, YRC yaw angular velocity command signal

Claims

1. a heading command generating unit that generates a heading command signal indicating the heading in which the vessel should proceed; a yaw angle detection unit that outputs a yaw angle signal indicating a rotation angle around a vertical axis passing through the center of gravity of the vessel; a yaw angular velocity detection unit that outputs a yaw angular velocity signal that indicates a rotational angular velocity around a vertical axis passing through the center of gravity of the vessel; a rudder angle detection unit that outputs a rudder angle signal indicating the angle of the rudder of the ship; a vessel speed detection unit that outputs a vessel speed signal indicating the vessel speed; a heading control unit that outputs a rudder angle command signal for directing the vessel toward the desired heading, based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a rudder angle control unit that controls the rudder based on the rudder angle command signal output by the azimuth control unit; a calculation feasibility determination unit that determines whether frequency characteristics can be calculated based on the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, a control gain adjustment unit that calculates each of the frequency characteristics of the yaw angle signal and the yaw angular velocity signal with respect to the rudder angle signal output by the rudder angle detection unit and adjusts a control gain of the directional control unit.

2. 2. The ship direction control device according to claim 1, wherein the calculation feasibility determination unit of the control gain adjustment unit determines whether the frequency characteristics can be calculated based on at least one of the degree of correlation, amplitude, amount of change, signal-to-noise ratio, and fluctuation ratio due to disturbance of the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal.

3. 3. A vessel direction control device according to claim 2, wherein the calculation feasibility determination unit of the control gain adjustment unit changes a comparison threshold value, which determines whether the frequency characteristics can be calculated based on at least one of the degree of correlation, amplitude, amount of change, signal-to-noise ratio, and rate of fluctuation due to disturbance, of the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, in accordance with the vessel speed signal.

4. 2. The vessel heading control device according to claim 1, wherein the calculation possibility determination unit of the control gain adjustment unit allows the calculation of the frequency characteristic when a change amount of the rudder angle signal is larger than a predetermined change amount.

5. 2. A vessel heading control device according to claim 1, wherein the control gain adjustment unit calculates a calculation accuracy when calculating the frequency characteristics of the yaw angle signal and the yaw angular velocity signal relative to the rudder angle signal, and adjusts the control gain of the heading control unit based on the calculated frequency characteristics when the calculation accuracy is higher than a predetermined accuracy.

6. The vessel heading control device according to claim 5 , wherein the control gain adjuster learns the calculated frequency characteristics when the calculation accuracy is higher than a predetermined accuracy.

7. The vessel heading control device according to claim 6, wherein the control gain adjuster performs learning by weighting the calculated frequency characteristics in accordance with the calculation accuracy.

8. 2. A vessel heading control device according to claim 1, wherein the control gain adjustment unit calculates a rudder angle offset, which is a rudder angle when the vessel is sailing straight ahead, and adjusts the control gain of the heading control unit.

9. 9. The vessel heading control device according to claim 8, wherein the control gain adjuster calculates the rudder angle offset amount by a difference equation based on a model in which the rudder angle offset amount is explicitly expressed.

10. 9. A vessel heading control device according to claim 8, wherein the rudder angle control unit controls the rudder based on the rudder angle command signal and the rudder angle offset amount.

11. The vessel direction control device according to claim 8 , wherein the calculation possibility determination unit of the control gain adjustment unit determines whether the frequency characteristic can be calculated based on the rudder angle signal and the rudder angle offset amount.

12. The direction control unit a first control calculation unit that calculates a yaw angular velocity command signal that makes the deviation between the azimuth command signal and the yaw angle signal zero; a second control calculation unit that calculates a feedback steering angle command signal such that a deviation between the yaw angular velocity command signal calculated by the first control calculation unit and the yaw angular velocity signal becomes zero; a third control calculation unit that calculates a feedforward steering angle command signal based on the yaw angular velocity command signal; 2. A vessel heading control device according to claim 1, further comprising an adder that adds the feedback rudder angle command signal calculated by the second control calculation unit and the feedforward rudder angle command signal calculated by the third control calculation unit to output a rudder angle command signal.

13. The control gain adjustment unit a reference transfer function setting unit that sets, for the steering angle signal, a yaw angle signal reference transfer function having a frequency characteristic to be targeted for the yaw angle signal, and a yaw angular velocity signal reference transfer function having a frequency characteristic to be targeted for the yaw angular velocity signal; 2. A vessel heading control device according to claim 1, further comprising an online gain adjustment unit that adjusts a control gain of the heading control unit based on the yaw angle signal reference transfer function and the yaw angular velocity signal reference transfer function set by the reference transfer function setting unit.

14. a step of generating a heading command signal indicating a heading in which the vessel should proceed by a heading command generating unit; a step of outputting a yaw angle signal indicating a rotation angle around a vertical axis passing through the center of gravity of the vessel by a yaw angle detection unit; a step of outputting a yaw angular velocity signal indicating a rotation angular velocity around a vertical axis passing through the center of gravity of the vessel by a yaw angular velocity detection unit; a step of outputting a rudder angle signal indicating the angle of the rudder of the vessel by a rudder angle detection unit; a step of outputting a rudder angle command signal by the heading control unit to direct the vessel in a desired heading based on the heading command signal generated by the heading command generation unit, the yaw angle signal output by the yaw angle detection unit, and the yaw angular velocity signal output by the yaw angular velocity detection unit; a step of controlling the rudder by a rudder angle control unit based on the rudder angle command signal; a calculation feasibility determination unit included in a control gain adjustment unit determines whether frequency characteristics can be calculated based on the rudder angle signal, the yaw angle signal, and the yaw angular velocity signal, and if the calculation feasibility determination unit determines that the frequency characteristics can be calculated, the control gain adjustment unit calculates each of the frequency characteristics of the yaw angle signal and the yaw angular velocity signal with respect to the rudder angle signal, and adjusts a control gain of the azimuth control unit.

15. The step of outputting the steering angle command signal by the direction control unit includes: a step of calculating, by a first control calculation unit, a yaw angular velocity command signal that makes the deviation between the azimuth command signal and the yaw angle signal zero; a step of calculating, by a second control calculation unit, a feedback steering angle command signal that sets a deviation between the yaw angular velocity command signal calculated by the first control calculation unit and the yaw angular velocity signal to zero; a step of calculating a feedforward steering angle command signal based on the yaw angular velocity command signal by a third control calculation unit; 15. A method for controlling a heading of a ship according to claim 14, further comprising a step of adding, by an adder, the feedback rudder angle command signal calculated by the second control calculation unit and the feedforward rudder angle command signal calculated by the third control calculation unit, and outputting a rudder angle command signal.

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