JP2021064248A - Automatic ship steering system for ship - Google Patents

Abstract

To provide an automatic ship steering system for ships capable of controlling steering of a ship by integrating TCS and BCS with each other.SOLUTION: An automatic ship steering system 1 for ships includes a propelling drive 4 capable of controlling the speeds in surge and sway directions and an angular speed about a yaw axis, and a sensor 5 that detects the azimuth of a bow and the position of a hull. The automatic ship steering system further includes a route control unit that performs feedback control on a hull position y and bow azimuth ψ in the sway direction of a ship so that the ship will follow a predesignated plan route, a position control unit that performs feedback control on the hull position (x, y) in the surge and sway directions of the ship so that the hull position (x, y) will be consistent with an arrival position (xB, yB) representing a destination of the plan route, and a mode change unit 15 that changes a movement mode in which the route control unit performs the feedback control, and a retention mode in which the position control unit performs the feedback control, on the basis of a separate distance between the arrival position (xB, yB) and the hull position (x, y).SELECTED DRAWING: Figure 1

Description

The present invention relates to an automatic ship maneuvering device for ships that controls takeoff and landing.

In recent years, there has been an increase in demand for a takeoff and landing control system (hereinafter, BCS: Berthing Control System) that automatically controls the takeoff and landing pier of a ship for the purpose of improving convenience and realizing systematization with navigation equipment. doing. BCS is a system that moves and holds the hull direction and the hull position from the starting point to the reaching point, and Non-Patent Documents 1 and 2 are known as a control method thereof.

In addition, as a technology related to a route control system (hereinafter, TCS: Track Control System) that follows a planned route, a feedback control unit that outputs a command steering angle is used as an estimator that estimates orientation error, route error, and tidal current. , The azimuth control system feedback gainer that constitutes the azimuth control loop and the route control system feedback gainer that constitutes the route control loop including the azimuth control loop, and the estimator is set to the azimuth control system feedback gainer in the way direction. An automatic marine steering device characterized by inputting a correction amount based on a tidal current estimation error is known (see, for example, Patent Document 1).

Kuniharu Ose, Junji Fukuto, Kenji Kanno, Shigeru Akagi, Mihide Harada, "Study on Automatic Shipbuilding and Departure System", Proceedings of the Japan Shipbuilding Society, No. 160, 1986, p. 103-p. 110 Takeo Koyama, Kim Gan, and Kim Yue, "Systematic Consideration of Automatic Shipbuilding and Detachment (1st Report)", Proceedings of the Japan Shipbuilding Society, No. 162, 1987, p. 201-p. 210

Japanese Unexamined Patent Publication No. 2016-159695

An object to be solved by the present invention is to provide an automatic ship maneuvering device capable of controlling ship maneuvering by integrating TCS and BCS.

In one embodiment, an automatic ship maneuvering device for controlling a ship including a propulsion drive device capable of controlling speeds in the serge direction and the way direction and an angular speed around the yaw, and sensors for detecting the bow orientation and the hull position. Therefore, the hull position is set to a route control unit that performs feedback control of the hull position and the bow direction of the ship in the sway direction so as to follow the preset planned route, and the hull position to the destination position in the planned route. A position control unit that feedback-controls the hull position of the ship in the serge direction and the way direction so as to match, and a movement mode in which the route control unit performs feedback control based on the separation distance between the arrival position and the hull position. A mode switching unit for switching between a holding mode in which feedback control is performed by the position control unit is provided.

It is a block diagram of the whole system including an automatic ship maneuvering device for a ship and a controlled object. It is a block diagram which shows the structure of a feedback control part. It is a figure which shows the planned route and the control mode. It is a figure which shows the hull model. It is a figure which shows the characteristic of the azimuth thruster. It is a figure which shows the error in a holding mode. It is a figure which shows the error in the movement mode. It is a figure which shows the control target corresponding to each of the movement mode and the holding mode. It is a figure which shows the speed control in a serge direction. It is a figure which shows the time series of a reference speed. It is a figure which shows the hull speed and the tidal current component. It is a figure which shows the simplified speed control. It is a figure which shows the position control in the surge direction. It is a figure which shows the control gain which concerns on the speed control in a simulation. It is a figure which shows the control gain which concerns on the position control in a simulation. It is a figure which shows the planned route and the hull track in the simulation result. It is a figure which shows the hull momentum in the simulation result. It is a figure which shows the error amount in the simulation result. It is a figure which shows the operation amount in the simulation result.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(1.1 Configuration of automatic ship maneuvering device for ships)
First, a system including an automatic ship maneuvering device according to the present embodiment will be described. FIG. 1 is a block diagram of the entire system including an automatic ship maneuvering device and a controlled object. FIG. 2 is a block diagram showing a configuration of a feedback control unit.

As shown in FIG. 1, the automatic ship maneuvering device 1 in the present embodiment controls a hull 3 provided with a propulsion drive device 4 and sensors 5, and causes the hull position to follow a planned route. _{, The device is a device in which the speed n u} , θ _{v in} the serge direction and the sway direction, and the angular velocity θ _r around the yaw are controlled by a controllable propulsion drive device 4 so as to match the arrival position which is the final point in the planned route. Here, the propulsion drive device 4 is an azimuth thruster provided at the bow and the stern.

The automatic ship maneuvering device 1 includes a track planning unit 11, an error calculation unit 12, a feedback control unit 13, a speed estimation unit 14, and a mode switching unit 15. The planned route is input from the guidance system 2 to the orbit planning unit 11, and from the orbit planning unit 11, the reference direction ψ _R , the reference position x _R , y _R , the reference speed u _R , the arrival direction ψ _B , the arrival position x _b , y. A reference signal including _{b is output.} Here, the reference direction ψ _R is the direction for making the hull 3 follow the route, and the reference positions x _R and y _R are one point on the route. Further, the arrival positions x _b and y _b are the end points of the planned route and the positions of the destination points, and the arrival directions ψ _B are the directions to which the hull 3 should face at the preset arrival positions x _b and y _b.

The sensors 5 of the hull 3 include a gyrocompass that detects the bow orientation ψ of the hull 3, and a GNSS sensor that detects the hull position (x, y) from a satellite positioning system (GNSS) such as GPS. The sensors 5 may include sensors capable of detecting the bow direction ψ and the hull position (x, y), respectively.

The hull position (x, y) of the detection signals from the sensors 5 is input to the speed estimation unit 14, and the speed estimation unit 14 estimates the speed of the hull 3 based on the hull position (x, y). And output as the estimated speed u ^.

A detection signal from sensors 5 such as the nose direction ψ and the hull position (x, y) and an estimated speed u ^ from the speed estimation unit 14 are input to the error calculation unit 12, and the error calculation unit 12 inputs the reference direction. ψ _R , reference position x _R , y _R , arrival direction ψ _B , arrival position x _b , y _b , reference speed u _R are compared with the detection signal and estimated speed, and the orientation error ψ _e and the route error y _e , Position error x _e , y _e , and velocity error u _e are output.

As shown in FIG. 2, the feedback control unit 13 includes a route control unit 132 and a position control unit 133. Route control unit 132, yaw angular velocity theta _r to reduce the azimuth error [psi _e, route error _{y e,} surge speed _n u to reduce respectively the speed error _{u e,} output to the propulsion drive 4 sway velocity theta _v as a controlled variable To do. The position control unit 133 outputs the yaw angular velocity θ _{r that reduces the directional error ψ e} , the surge velocity n _u that reduces the position errors x _e , and y _e , and the sway velocity θ _v as control amounts to the propulsion drive device 4.

The mode switching unit 15 has a movement mode in which the route control unit 132 outputs the control amount to the propulsion drive device 4 and a holding mode in which the position control unit 133 outputs the control amount to the propulsion drive device 4 based on the conditions described later. To switch. Further, the mode switching unit 15 also switches the error calculation unit 12 between the moving mode and the holding mode.

In the movement mode, the error calculation unit 12 has an error _{between the reference direction ψ R} and the bow direction ψ, an error in the hull position in the way direction with respect to the planned route, a reference speed u _R, and an estimated speed u ^ output by the speed estimation unit 14. error between the respective azimuth error [psi _e, and outputs route error _{y e,} a speed error _{u e} to route control unit 132 of the feedback control unit 13.

Further, in the holding mode, the error calculation unit 12 sets the error _{between the arrival direction ψ B} and the bow direction ψ and the error between the arrival positions x _b and y _b and the hull position x and y as the direction error ψ _e and the position, respectively. It is output to the position control unit 133 of the feedback control unit 13 as errors x _e and y _e.

(1.2 Planned route and control mode)
The planned route will be explained. FIG. 3 is a diagram showing a planned route and a control mode.

As shown in FIG. 3, the movement / holding of the hull position causes the hull track to follow the planned route. In FIG. 3, O-XY is the fixed coordinates of the earth, point A is the starting point of the hull position, point B is the reaching point, point W is the waypoint which is the intermediate point from point A to point B, and point C is the turning center. is there. Waypoints are set to accommodate a variety of planned routes.

The planned route is composed of a combination of straight lines and curved lines, and the automatic ship maneuvering device 1 controls the ship so as to navigate on the planned route in the movement mode and the holding mode. The automatic ship maneuvering device 1 generally controls navigation from point A, which is the departure position, to point B, which is the arrival position, along the planned route along the following sequence.

First, the automatic ship maneuvering device 1 converges the bow direction ψ of the hull at the point A _{from the initial direction ψ 0} to the planned direction ψ _AW by turning control (step 1). The planned direction ψ _AW faces the point W side in the straight line AW direction in FIG. Next, the automatic ship maneuvering device 1 shifts the hull position from the point A to the point B according to the movement mode and the holding mode (step 2), and similarly to step 1, the bow direction ψ at the point B is set to the planned direction ψ. Match the arrival direction ψ _{B from the WB} (step 3). Here, the planned direction ψ _WB faces the point B side in the straight line WB direction in FIG. 3, and the arrival direction ψ _B is a direction preset as the bow direction ψ at the point B. The turning control is composed of turning motion and directional control, as will be described later.

(1.3 Hull model)

The hull motion model can be expressed by a linear term with three degrees of freedom as follows.

ここで、ξ＝［ｕ ｖ ｒ］^Ｔ，γ＝［γ_ｕ γ_ｖ γ_ｒ］^Ｔは推進駆動装置４の推力とモーメント、添字^Ｔは転置行列、添字_ｕ，_ｖ，_ｒは、それぞれ、ｓｕｒｇｅ，ｓｗａｙ，ｙａｗの運動成分を示し、一定船速はｕ_０≒０とし、

Here, ξ = [uv r] ^T , γ = [γ _u γ _v γ _r ] ^T is the thrust and moment of the propulsion drive device 4, the subscript ^T is the transposed matrix, and the subscripts _u , _v , and _r are surges, respectively. , Way, yaw kinetic components are shown, and the constant ship speed is u ₀ ≒ 0.

である。ここで、Ｘ_ｕ・，Ｘ_ｕ，Ｙ_ｖ・，Ｙ_ｒ・，Ｎ_ｖ・，Ｎ_ｒ・，Ｙ_ｖ，Ｙ_ｒ，Ｎ_ｖ，Ｎ_ｒは流体微係数、ｍは質量、Ｉ_ｚはｙａｗ周りの慣性モーメント、ｘ_Ｇは船体中央から重心までの距離である。

Is. Here, X _{u ·} , X _u , Y _{v ·} , Y _{r ·} , N _{v ·} , N _{r ·} , Y _v , Y _r , N _v , N _r are fluid fine coefficients, m is mass, and I _z is yaw. The moment of inertia around, x _G, is the distance from the center of the hull to the center of gravity.

(1) If you rewrite the formula,

になる。ここで、

become. here,

ここで、添字^−１は逆行列

Where subscript ^-1 is the inverse matrix

である。

Is.

The hull model separates equation (4) into a surge component and a sway and yaw components, and Laplace transforms them. The surge component is

になる。ここで、ｓはラプラス演算子、Ｐ_ｕ（Ｓ）はｓｕｒｇｅ運動の伝達関数

become. Here, s is a Laplace _{operator, P} u (S) is the transfer function of the surge motion

である。ここで、Ｔ_ｕ，Ｋ_ｕはそれぞれ時定数とゲインである。ｓｗａｙ，ｙａｗ成分は、船体運動を１次式で表すと、

Is. _Here, T u, the _{K u} is a constant and the gain at each. The sway and yaw components express the hull motion as a linear equation.

となる。ここで、Ｐ_ｖ（ｓ），Ｐ_ｒ（ｓ）はｓｗａｙ，ｙａｗ運動の伝達関数

Will be. _{Here, P v (s), P} r (s) is sway, the transfer function of the yaw motion

である。ここで、Ｔ_ｖ，Ｔ_ｒ，Ｋ_ｖ，Ｋ_ｒは船体パラメータであり、それぞれ２つの時定数とゲインである。上式の係数は近似したため、値を特定できない。船体パラメータはすべて正とする。

Is. Here, T _v , _Tr , K _v , and _Kr are hull parameters, which are two time constants and gains, respectively. Since the coefficients in the above equation are approximated, the value cannot be specified. All hull parameters are positive.

Since the hull fixed coordinate system is used for the hull speed and the earth fixed coordinate system is used for the hull position, the relationship between the two is

になる。ここで、ψは方位、ｘ，ｙはそれぞれ北向き、東向きの船体位置である。

become. Here, ψ is the direction, and x and y are the hull positions facing north and east, respectively.

(1.4 Azimuth thruster model)
An azimuth thruster model (hereinafter referred to as ATM: Azimuth Thruster Model) will be described. FIG. 4 is a diagram showing a hull model. FIG. 5 is a diagram showing the characteristics of the azimuth thruster.

The ATM of the propulsion drive device 4 controls the thrust vector according to the propeller rotation speed and its direction. In FIG. 4, the γ generated from the two ATMs is

になる。ここで、添字_ｆ，_ａはそれぞれｆｏｒｅ（船首）、ａｆｔ（船尾）を示し、Ｆは対水推力、ｎはプロペラ回転数、ｎ_０は一定回転数、θは船の基線からの推力方向の角度であり、ｌはミッドシップから推進駆動装置４までのレバー長でｌ_ｆ＝ｌ_ａ＝ｌである。

become. Here, the subscripts _f and _a indicate fore (bow) and aft (stern), respectively, F is thrust against water, n is propeller rotation speed, n ₀ is constant rotation speed, and θ is the thrust direction from the baseline of the ship. It is an angle, and l is the lever length from the midship to the propulsion drive device 4, and l _f = l _a = l.

The characteristics of the ATM rotation speed and thrust are shown in FIG. In FIG. 5, the thrust coefficient of _{n 0 is calculated.}

とする。ここで、ｎ_ｆ０＝ｎ_ａ０＝ｎ_０，ｆ_ｎ０は推力微係数である。

And. Here, n _f0 = n _a0 = n ₀ , f _n0 is a thrust coefficient.

Substituting the above equation into equation (14), γ becomes

となる。ここで、近似ｃｏｓθ≒１，ｓｉｎθ≒θを用いる。

Will be. Here, the approximation cos θ≈1, sinθ≈θ is used.

On the other hand, if the ATM input is replaced with _{control quantities n u} , θ _v , and θ _r,

になる関係をもつ。ここで、ｎ_ｕはｓｕｒｇｅ速度、θ_ｖはｓｗａｙ速度、θ_ｒはｙａｗ角速度である。上式を（１６）式に代入すると

Have a relationship to become. Here, n _u is a surge velocity, θ _v is a sway velocity, and θ _r is a yaw angular velocity. Substituting the above equation into equation (16)

になる。よって、上式をそれぞれ（８），（１０）式に代入すると、船体モデルの伝達関数は

become. Therefore, if the above equations are substituted into equations (8) and (10), respectively, the transfer function of the hull model will be

となる。ここで、Ｋ_ｕ，Ｋ_ｖ，Ｋ_ｒは推進駆動装置４のゲインを乗じたもので置換する。

Will be. _{Here, K u, K v, K} r is replaced by multiplied by the gain of the propulsion drive 4.

(1.5 Disturbance component)

Disturbance component is a tidal component _u c, _{v c} and the azimuth axis angular velocity r _o. When formulated, it becomes the following equation.

ここで、ｕ_ｃ，ｖ_ｃは対地座標成分で、それぞれ北向き、西向きの速度である。

Here, u _c and v _c are the coordinate components to the ground, and are the velocities facing north and west, respectively.

(2 control system)

The control system will be described.

(2.1.1 Control target)
In equation (13), when the orientation is linearized with ψ = 0, the following equation is obtained.

制御対象は上式、（２１）式の船体モデルと（２２）式の外乱モデルとを用いて次式になる。

The control target is the following equation using the above equation, the hull model of equation (21) and the disturbance model of equation (22).

(2.1.2 error)
The error in the holding mode and the moving mode will be described. 6 and 7 are diagrams showing errors in the holding mode and the moving mode, respectively.

The error of the holding mode is defined as shown in FIG. 6, and the error of the moving mode is defined as shown in FIG. As shown in FIGS. 6 and 7, the arrival position is referred to in the holding mode, and the planned route is referred to in the moving mode. The orientation error ψ _e is set in both the holding mode and the moving mode.

になる。ここで、ψは船首方位、ψ_Ｒは参照方位である。保持モードにおける位置誤差ｘ_ｅ，ｙ_ｅは地球座標系で

become. Here, ψ is the bow direction and ψ _R is the reference direction. Positional errors x _e and y _e in retention mode are in the Earth coordinate system

になる。ここで、ｘ，ｙは船体位置、ｘ_ｂ，ｙ_ｂは到達位置である。制御器の入力になる位置誤差は船体座標系になるので、位置誤差を座標変換すると

become. Here, x and y are hull positions, and x _b and y _b are arrival positions. The position error that is the input of the controller is the hull coordinate system, so if you convert the position error to the coordinates

になる。ここで、Ｔ^Ｅ _Ｂ（ψ）は地球座標（添字_Ｅ）から船体座標（添字_Ｂ）に変換する行列

become. ^{Here, T} _{E B} ^(ψ) is converted from the global coordinates (subscript _E) to the hull coordinates (subscript _B) matrix

添字^−１は逆行列である。

Subscript ^-1 is an inverse matrix.

In FIG. 7, which shows the error of the movement mode, the point P indicates the hull position, the point H indicates the foot _{drop from P, and the route error y e} > 0 (right-handed system) is the length of the foot drop. Speed error _{u e} is

になる。ここで、ｕ＾は速度推定部１４により推定される推定速度、ｕ_Ｒは軌道計画部１１により出力される参照速度である。旋回半径ｒａｄｉｕｓは

become. Here, u ^ is the estimated speed estimated by the speed estimation unit 14, and u _R is the reference speed output by the trajectory planning unit 11. The turning radius radius is

になる。ここで、ｒ_Ｒは軌道計画部１１により出力される参照角速度である。

become. Here, r _R is the reference angular velocity output by the orbit planning unit 11.

(2.1.3 Controller)
The controller in the feedback control unit will be described. FIG. 8 is a diagram showing a control target corresponding to each of the movement mode and the holding mode.

The transmission characteristics of the controller in the feedback control unit are given by the following equation in hull coordinates.

ここで、Ｃ_ｕ（ｓ）はｓｕｒｇｅ速度の制御器、Ｃ_ｘはｓｕｒｇｅ位置の制御器、Ｃ_ｙはｓｗａｙ位置の制御器、Ｃ_ψはｙａｗ角度の制御器である。

_{Here, C} u (s) is the surge speed controller, the _{C x} controller of surge position, _{C y} is the controller of the sway position, the C _[psi a controller of yaw angle.

As shown in FIG. 8, in the movement mode, the serge speed, the sway position and the yaw angle are controlled targets, and in the holding mode, the sage position, the sway position and the yaw angle are controlled targets.

(2.2 movement mode)
The movement mode will be described. FIG. 9 is a diagram showing speed control in the serge direction.

The route control unit 132 that outputs a control amount when the movement mode is switched has two control operations, speed control and route control. As shown in FIG. 9, the speed control is a control operation in which the serge speed is made to follow the reference speed. Route control is a control operation that causes the hull position to follow the reference route. The route control _{converges the route error y e} to zero, and is carried out by _Cy (s) of Eq. (34). _Cy (s) will be described later in the description of the holding mode, and speed control will be described in this section.

(2.2.1 Reference speed)
The reference speed u _R will be described. FIG. 10 is a diagram showing a time series of reference speeds.

The reference speed u _R is calculated by the trajectory planning unit 11 based on the set value. As shown in FIG. 10, the reference speed u _R has three sections arranged in chronological order in the order of _{acceleration time T acc} , constant velocity time T _vol, and deceleration time T _{dec , and has acceleration time T acc} and deceleration time T _dec. The acceleration / deceleration in is the ramp inclination. The constant velocity continues until the foot drop position on the reference route from the hull position reaches the deceleration start position. Variables related to the reference speed are set in the trajectory planning unit 11.

(2.2.1 Estimated hull speed)
The estimated value of the hull speed calculated by the speed estimation unit will be described. FIG. 11 is a diagram showing the hull velocity and the tidal current component.

As shown in Fig. 11, the ground speed is the sum of the hull component and the tidal current component.

になる。ここで、ｕ，ｖはそれぞれ北向きと東向きの速度成分、添字ｇ，ｎ，ｃはそれぞれ、対地、船体、潮流の成分を示し、

become. Here, u and v indicate the velocity components facing north and east, respectively, and the subscripts g, n and c indicate the components of the ground, hull and tidal current, respectively.

であり、ここで、Ｕ_ｃは潮流速度、ψ_ｃは潮流方位である。

Here, U _c is the tidal current velocity and ψ _c is the tidal current direction.

Because the ground speed corresponds to the change in hull position per hour.

になる。ここで、Δｔはサンプリング時間、添字ｋは基点でｋ＝１，２，…である。よって、船体速度の推定値は次式になる。

become. Here, Δt is the sampling time, and the subscript k is k = 1, 2, ... At the base point. Therefore, the estimated value of the hull speed is given by the following equation.

ここで、添字＾は推定値である。上式は潮流成分を含んだ船体速度になる。

Here, the subscript ^ is an estimated value. The above formula is the hull velocity including the tidal current component.

(2.2.2 Speed feedback control)
The speed feedback control will be described.

Speed feedback control _Cu (s)

となる。ここで、Ｃ_ｕ（ｓ）はＰＩ制御の伝達関数で

Will be. Here, _Cu (s) is a transfer function of PI control.

であり、ここで、ｓはラプラス演算子、Ｋ_ｐｕは比例ゲイン、Ｔ_ｉｕは積分時定数、Ｆ_ｕ（ｓ）はローパスフィルタの伝達関数で

Where s is the Laplace operator, K _pu is the proportional gain, T _iu is the integral time constant, and _Fu (s) is the transfer function of the low-pass filter.

とする。ここで、添字_ｆはフィルタを意味し、Ｔ_ｆｕは時定数である。
（２．２．３ 速度制御の特性）
速度制御の特性について説明する。図１２は、簡略化した速度制御を示す図である。

And. Here, the subscript _f means a filter, and T _fu is a time constant.
(2.2.3 Characteristics of speed control)
The characteristics of speed control will be described. FIG. 12 is a diagram showing simplified speed control.

The transmission characteristics and steady-state characteristics of the speed error shown in FIG. 12 are shown.

になる。ここで、Ｕ_ｅ（ｓ），Ｕ_Ｒ（ｓ）はそれぞれ速度誤差、参照速度であり、Ｕ_Ｒ（ｓ），Ｕ_ｃ（ｓ）の初期値は

become. _{Here, U e (s), U} R (s) , respectively the speed error, a reference _speed, the initial value of _{U R (s), U c} (s) is

である。よって、速度制御の特性は、潮流成分を含んだ速度を参照速度に追従させるものである。

Is. Therefore, the characteristic of velocity control is to make the velocity including the tidal current component follow the reference velocity.

(2.2.4 turning motion)
The turning motion will be described.

As shown in FIGS. 3 and 7, the turning motion is carried out around the point C, and the bow direction is made to follow the reference direction by the directional control. The reference direction is

になる。ここで，ψ_Ｒ０は初期方位、ｒ_Ｒは参照角速度，ｋは基点でｋ＝１，２，…，ｈである。旋回角はΔψ_Ｒ＝ｒ_ＲΔｔ・ｈになる。ψ_Ｒ０，ｒ_ＲとΔψ_Ｒは軌道計画で設定する。方位制御については、（３４）式から移動モードと保持モードとで共通なので、次節において後述する。

become. Here, ψ _R0 is the initial direction, r _R is the reference angular velocity, and k is the base point where k = 1, 2, ..., H. The turning angle is Δψ _R = r _R Δt · h. ψ _R0 , r _R and Δψ _R are set in the orbital plan. Since the directional control is common to the movement mode and the holding mode from the equation (34), it will be described later in the next section.

(2.2.5 mode switching)
The conditions for switching from the move mode to the hold mode will be described.

As shown in FIG. 3, the planned route enters the holding mode from the position before the point B. The distance from that position to the point B is called the _{buffer distance dist bf.} The dist _bf is for converging the ship speed remaining at the time of switching to zero. The estimated speed u ^ of the movement mode decelerates in the deceleration time T _{dec following the reference speed u R shown in FIG.}

という条件が満たされた場合にモード切替部１５は移動モードを保持モードに切り替える。ここで、ｕ_ｂｆは設定値である。また、モード切替部１５は、船体位置と点Ｂとの距離が緩衝距離ｄｉｓｔ_ｂｆ以下となった場合に移動モードを保持モードに切り替えても良い。

When the condition is satisfied, the mode switching unit 15 switches the movement mode to the holding mode. Here, u _bf is a set value. Further, the mode switching unit 15 may switch the movement mode to the holding mode when the distance between the hull position and the point B is _{equal to or less than the buffer distance dust bf.}

Since the deceleration time T _{dec at the} reference speed u _R is the last section in the time series of the movement mode, the mode switching based on the estimated speed u ^ is also indirectly based on the distance between the hull position and the point B. I can say.

(2.3 retention mode)
(2.3.1 Position feedback control)
Position feedback control will be described.

The position feedback control C (s) consists _{of three (subscript x} ), sway (subscript _y ), and yaw (subscript _ψ ), all of which have the same shape. The control is assumed that a low-pass filter LPF is added to the PID control. The transfer function K (s) of PID control is

とする。ここで、ｓはラプラス演算子、Ｋ_ｐは比例ゲイン、Ｔ_ｄは微分時定数、Ｔ_ｉは積分時定数である。ローパスフィルタの伝達関数Ｆ（ｓ）は

And. Here, s is the Laplace operator, K _p is the proportional gain, T _d is the differential time constant, and _Ti is the integral time constant. The transfer function F (s) of the low-pass filter is

とする。ここで、添字_ｆはフィルタを意味し、ζ_ｆは減衰係数、ω_ｆは固有角周波数である。よって、位置フィードバック制御器Ｃ（ｓ）は次式になる。

And. Here, the subscript _f means a filter, ζ _f is an attenuation coefficient, and ω _f is an intrinsic angular frequency. Therefore, the position feedback controller C (s) has the following equation.

(2.3.2 Impact of disturbance)
The effects of disturbance will be explained. FIG. 13 is a diagram showing position control in the serge direction.

Investigate the error due to the disturbance component. The control system consists of a serge, a way direction, and a yaw circumference. In surge direction of the position control shown in FIG. 11, the subscript _u denotes the surge _{direction, C} u (s) is a feedback _{controller, P} u (s) is a control target, _X (s), X _R (S) and X _e (s) are the hull position, the reference position, and the error, respectively, and U _c (s) is the tidal current component. The following equation is obtained when the error transmission characteristics are obtained.

ここで、

here,

である。ここで、簡単化のためフィードバック制御器からＬＰＦを除き、Ｋ_ｕ，Ｔ_ｕは船体運動モデルのパラメータである。

Is. Here, except for the LPF from the feedback controller for simplicity, K _u, T _u is a parameter of the hull motion model.

When the error related to the tidal current component is calculated by Eq. (51),

になる。ここで、ｕ_ｃ（０），ｕ_ｃ ^・（０）は一定値である。

become. ^{_{Here, u c (0), u}} c · (0) is a constant value.

When the steady value of the error is obtained with or without the integrator of the controller

になる。ここで、ｘ_ｅ（ｔ→∞）＝ｌｉｍ_ｓ→０ｓＸ_ｅ（ｓ）を用いる。よって，積分器を用いれば、外乱成分が一定値のときには誤差がゼロに収斂し（１型サーボ特性）、外乱成分がランプ状のときには誤差がバイアスを生じる（０型サーボ特性）こととなる。

become. Here, x _e (t → ∞) = lim _{s → 0} sX _e (s) is used. Therefore, if an integrator is used, the error converges to zero when the disturbance component is a constant value (type 1 servo characteristic), and the error is biased when the disturbance component is lamp-shaped (type 0 servo characteristic).

In addition, the following situations may occur in the hull coordinates when the hull 3 is in a turning motion because the disturbance component is lamp-shaped.

・ A certain disturbance component fluctuates depending on the azimuth angle, and the controller cannot follow it, causing an error.
-While turning, stopping the integrator can suppress the increase in error.
-The occurrence of error depends on the relative relationship between the control system and the disturbance characteristics.

There is a method of estimating the tidal current component to suppress the error, but it requires a water velocity.

(3 verification)
We will verify the proposed method by simulation and confirm its effectiveness.

(3.1 conditions)
The simulation conditions will be described. 14 and 15 are diagrams showing control gains related to speed control and position control in simulation, respectively.

The hull model in the simulation is captain L = 30 m, mass m = 300 × 10 ³ kg,

である。ここで、数値は、Ｔ．Ｉ．Ｆｏｓｓｅｎ ａｎｄ Ｔ．Ｐｅｒｅｚ． Ｍａｒｉｎｅ ｓｙｓｔｅｍｓ ｓｉｍｕｌａｔｏｒ， ２００８．を引用する。

Is. Here, the numerical value is T.I. I. Fossen and T. Perez. Marine systems simulator, 2008. To quote.

The propulsion drive device 4 has l = L / 2 = 15 m, n ₀ = 200 rpm, f _{n 0} = 700 kgf · rpm ^-1 , and an opening limit value of 45 deg.

The control gain is set as shown in FIGS. 14 and 15. The planned route is point A = (0,0), point B = (0,500), point W = (300,300), where the unit is [m]. Regarding the movement mode, u _R = 2 m / s, T _acc = T _dec = 60 s, r _R = 2 deg / s, radius = 57.3 m, Δψ _R = 101.3 deg, dist _bf = 30 m, u _bf = It is set to 0.1 m / s. Further, the disturbance component, tidal components _{(U c = 3m / s,} ψ c = 0deg), the angular velocity _r o = 1deg / s. The sampling time is Δt = 0.1s.

(3.2 result)
The simulation results will be described. 16 to 19 are diagrams showing the planned route, the hull track, the hull momentum, the error amount, and the operation amount in the simulation results, respectively.

As shown in FIG. 16, the hull position causes a navigation error due to the influence of disturbance during the movement mode, but it converges to the point B which is the arrival position. Further, as shown in FIG. 17, it can be seen that u ^ is affected by v and r and v is affected by the coupled motion with r during turning. Further, as shown in FIG. 18, since the error causes a transient response when the mode is switched and gradually approaches zero with time, it can be seen that the closed loop stability can be ensured. Further, as shown in FIG. 15, it can be seen that the manipulated variable θ is saturated at the initial stage, and θ and n show a steep response in part.

(4 Summary)
The following is a summary of the automatic ship maneuvering device for switching between the movement mode and the holding mode, considering the results of verifying the effectiveness by simulation.

-Proposed the design of a control system that integrates TCS and BCS.
-Proposed a design of a control system that included speed control without using water speed.
-The control target was divided into serge, sway, and yaw, and the response models for each were shown.
・ The characteristics of the closed loop control system for disturbance components were analyzed.
-Adopted speed control and turning control as the movement mode of the planned route.
-By using the reference speed and the estimated speed for speed control, the influence of tidal current disturbance could be canceled out.
・ Waypoints can be introduced into the planned route by turning control, enabling various route plans.
・ By the proposed method, the ship position could be moved from the starting point to the reaching point.

The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Automatic ship maneuvering device 4 Propulsion drive device 5 Sensors 13 Feedback control unit 15 Mode switching unit 132 Route control unit 133 Position control unit

Claims (6)

An automatic ship maneuvering device for controlling a ship, which includes a propulsion drive device capable of controlling speeds in the serge direction and the way direction and an angular velocity around yaw, and a sensor for detecting the bow direction and the hull position.
A route control unit that performs feedback control of the hull position and bow direction of the ship in the sway direction so as to follow a preset planned route.
A position control unit that feedback-controls the hull position in the serge direction and the way direction of the ship so as to match the hull position with the arrival position that is the destination in the planned route.
Automatic for ships including a mode switching unit that switches between a movement mode in which feedback control is performed by the route control unit and a holding mode in which feedback control is performed by the position control unit based on the distance between the arrival position and the hull position. Ship maneuvering device. The automatic ship maneuvering device according to claim 1, wherein the route control unit feedback-controls the serge speed of the ship so as to follow a preset reference speed. The reference speed is preset so as to gradually decelerate toward the arrival position, and the mode switching unit switches from the movement mode to the holding mode when the reference speed is equal to or less than a predetermined speed threshold value. The automatic ship maneuvering device for ships according to claim 2. The mode switching unit according to claim 1 or 2, wherein the mode switching unit switches from the moving mode to the holding mode when the distance between the reaching position and the hull position is equal to or less than a predetermined distance threshold value. Automatic ship maneuvering device for ships. Further provided with a speed estimation unit that estimates the ground speed of the ship based on the hull position,
The automatic ship operation according to claim 2 or 3, wherein the route control unit feedback-controls the serge speed of the ship based on an error between the reference speed and the estimated ground speed. Ship maneuvering device. The position control unit according to any one of claims 1 to 5, wherein the position control unit feedback-controls the bow direction so that the bow direction of the ship faces a preset arrival direction at the arrival position. The described automatic ship maneuvering device for ships.

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