JP2009248897A - Automatic ship steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic ship steering device for putting a ship in a planned turning track by considering the turning side-slip property of a hull and/or a tidal current component. <P>SOLUTION: The automatic ship steering device comprises a reference orientation generating part 30 for generating a reference orientation ψ<SB>R</SB>to carry out turn following a planed route, a side-slip correcting part 32 for finding a reference oblique sailing angle β<SB>R</SB>corresponding to the turning angle speed generated by steering from a reference angle speed r<SB>R</SB>as a time differentiation of the reference orientation ψ<SB>R</SB>, a coordinate converting part 40 for coordinate-converting the tidal current component estimated by an estimator in accordance with the reference orientation output by the reference orientation generating part to find the horizontal component of the tidal current to the hull, a tidal current correcting part 42 for finding a corrected oblique sailing angle β<SB>d</SB>opposite to the tidal current from the horizontal component coordinate-converted by the coordinate converting part 40, and a feedforward steering angle generating part 46 for generating a corrected feedforward steering angle in accordance with the reference orientation, the reference oblique sailing angle β<SB>R</SB>and the corrected oblique sailing angle β<SB>d</SB>in turning. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a marine vessel automatic steering device for a route control system, and more particularly to a marine vessel automatic steering device that can be traced to a planned route by taking into account a side slip angle and a tidal current component when turning.

  The automatic steering system for ships has a heading control system (HCS) that controls the steering angle and follows the heading to the set direction, and a track control system (TCS) that tracks the hull position on the planned route. ). The demand for navigation control systems has increased with the advancement of microchip functionality and the ease of obtaining location information through the downsizing, cost reduction, and high accuracy of the Global Navigation Satellite System (GNSS). Is growing.

As shown in FIG. 1, the general marine automatic steering device for a marine route control system includes a trajectory planning unit 12, a trajectory route error calculating unit 14, a feedback control unit 16, and an adder 17. Based on the planned route from the guidance system 22, an error between the reference azimuth ψ _R and the reference position x _R , y _R output from the trajectory planning unit 12, and the azimuth ψ detected by the sensor and the position x, y is calculated. Part 14 seeks. The feedback control unit 16 outputs a feedback steering angle δ _FB mainly for tracking the azimuth and position of the hull from the error at the time of holding. Further, the feed forward steering angle δ _FF is output from the trajectory planning unit 12 during turning. The adder 17 adds the feedback steering angle δ _FB and the feedforward steering angle δ _FF, and outputs the command steering angle δ _c to the hull steering machine. The planned route is determined from a straight line and a curved arc.

  The control time constant of the feedback control system of the route control system is longer than the control time constant of the direction control system, and the turn time is usually shorter than the time constant of the direction control system. It is difficult to converge with the control system.

  By the way, the hull generates a side-slip velocity due to a reaction force against water in the lateral direction of the hull at the same time as generating a turning angular velocity around the azimuth axis by steering. Therefore, due to this skid characteristic, the hull trajectory does not have the planned arc shape with respect to the planned route with a constant turning radius, resulting in a channel error. Also, the direction does not change immediately because the hull time constant is large after steering is started. Therefore, a distance (referred to as a reach) is generated between the turning start position and the turning start position. If the reach estimate is incorrect, it will result in a navigation error, so it is necessary to adjust the reach amount and the steering amount.

  In addition, when turning, the tidal component applied to the hull changes depending on the heading direction, and therefore, if the tidal component is not taken into account, a channel error will occur transiently.

  On the other hand, the inventor of the present application proposes, in Patent Document 1, Non-Patent Document 1, and Patent Document 2, a technique of reference azimuth and feedforward control that allows the heading to follow the reference azimuth without delay in the azimuth control system. ing.

Yuuki Hane, “Design method of reference course for route trajectory generation”, 6th Annual Conference of the Society of Instrument and Control Engineers, 2006 JP-A-8-207894 JP 2007-290695 A

  Therefore, the present invention is based on the reference direction and feedforward control that can follow the proposed heading without delay to the reference direction, and by taking into account the side-slip characteristics and / or tidal current components when turning the hull, An object of the present invention is to provide a marine vessel automatic steering device that can be placed on a trajectory of planned turning.

In order to achieve such an object, according to the first aspect of the present invention, the ship speed detected by the sensor is inputted, a reference signal is generated based on the planned route, and the trajectory of the planned route is placed when making a turn. In the ship automatic steering apparatus comprising a trajectory planning unit that outputs the feed forward rudder angle of
The trajectory planning unit
A reference azimuth generating unit for generating a reference azimuth ψ _R for making a turn in accordance with the planned route,
A skid correction unit for obtaining a reference skew angle β _R corresponding to a turning angular velocity generated by turning the rudder from a reference angular velocity r _R which is a time derivative of the reference orientation ψ _R ;
Based on the reference azimuth and the reference skew angle β _R , the feedforward rudder angle generating unit that generates a corrected feedforward rudder angle;
It is characterized by providing.

According to a second aspect of the present invention, the trajectory planning unit according to the first aspect further comprises:
Using reference direction ψ _R and ship speed U,

より参照速度ベクトル（ｕ_R，v_R）を求める参照速度発生部と、
前記参照速度ベクトルを積分することにより参照位置を出力する参照位置発生部と、
を備えることを特徴とする。

A reference speed generation unit for obtaining a reference speed vector (u _R , v _R ),
A reference position generator for outputting a reference position by integrating the reference velocity vector;
It is characterized by providing.

According to a third aspect of the present invention, there is provided a trajectory planning unit that receives a ship speed detected by a sensor, generates a reference signal based on the planned route, and outputs a feedforward steering angle for placing the trajectory on the planned route when turning. A trajectory route error calculation unit that calculates a trajectory error from the reference signal from the trajectory planning unit and a detection signal detected by the sensor, and a feedback control unit that outputs an estimated tidal current component and a feedback steering angle from the trajectory error. Prepared,
In the boat automatic steering apparatus that performs steering by the feedback steering angle and the feedforward steering angle,
The trajectory planning unit
A reference azimuth generating unit for generating a reference azimuth ψ _R for making a turn in accordance with the planned route,
A coordinate conversion unit that obtains a lateral component of the hull of the tidal current by performing coordinate conversion based on the reference direction output by the reference direction generation unit for the estimated current component,
A tidal current correcting section for obtaining a corrected tilt angle β _d that opposes the tidal current from the lateral component coordinate-converted by the coordinate converting section;
The feedforward steering angle generator for generating a corrected feedforward steering angle based on the reference azimuth and the corrected skew angle β _d ;
It is characterized by providing.

Fourth aspect of the present invention, the trajectory planning unit of claim 3, further, reference swash corresponding from the time derivative of the reference orientation [psi _R reference angular velocity r _R the turning angular velocity generated by cutting steering Wataru A skid correction part for obtaining the angle β _R is provided,
The coordinate conversion unit uses the reference course θ _R obtained by adding the reference direction ψ _R and the reference oblique angle β _R , from the estimated tidal component d _x ^, d _y ^,

に従い、潮流の船体の横方向成分v_d^を求めることを特徴とする。

According to the above, the transverse component v _d ^ of the tidal hull is obtained.

According to a fifth aspect of the present invention, the feedback control unit according to the third or fourth aspect includes an estimator that estimates a tidal component, and a feedback gain unit that calculates a feedback steering angle by applying a feedback gain from a trajectory error. Have
The trajectory planning unit calculates a correction amount obtained by applying the feedback gain of the feedback control unit to the corrected skew angle β _d facing the tidal current, and corrects the feedforward steering angle based on the correction amount. It further has a section.

The invention described in claim 6 includes a trajectory planning unit that generates a reference direction based on the planned route and outputs a feedforward rudder angle to be put on the trajectory of the planned route when turning, and performs open loop control. In an automatic steering device for a ship that performs steering by a feedforward rudder angle,
Prior to the start of turning steering, a reach calculating unit that calculates a distance (referred to as a reach) between the turning start position and the steering start position is provided.
A reference azimuth generator for obtaining a reference azimuth ψ _R from a turning radius obtained from the planned route and a predetermined turning angle;
A hull route generating unit for obtaining an expected hull route from the reference direction ψ _R ;
Find the distance in the azimuth direction (referred to as advance) from the steering start position to the position farthest in the azimuth direction at the start of the turn on the predicted hull route determined by the hull route generation unit, and subtract the turning radius from the advance With the reach output part which asks for reach,
It is characterized by providing.

According to a seventh aspect of the present invention, the reach calculation unit according to the sixth aspect of the present invention further includes:
A coordinate conversion unit that obtains a horizontal component of the hull of the tidal current by performing coordinate conversion on the estimated tidal current component based on the reference direction output by the reference direction generation unit;
A tidal current correcting section for obtaining a corrected tilt angle β _d that opposes the tidal current from the lateral component coordinate-converted by the coordinate converting section;
And the hull route generating unit obtains the predicted hull route using the corrected skew angle β _d .

  According to an eighth aspect of the present invention, the coordinate conversion unit according to any one of the third to seventh aspects performs a coordinate conversion on the basis of a reference azimuth output of a tidal current component by a reference azimuth generation unit, thereby generating a tidal hull The reference azimuth generating unit obtains a reference azimuth for making a turn according to the planned route according to a change in ground speed due to the bow directional component.

  The invention according to claim 9 is characterized in that the reference direction generation unit according to claim 8 outputs the reference direction using the specified turn angular velocity corrected according to the change in ground speed.

  According to a tenth aspect of the present invention, there is provided the marine vessel automatic steering apparatus according to any one of the first to ninth aspects of the present invention, based on the reference azimuth and estimated tidal current vector before turning and the reference azimuth and estimated tidal current vector after turning. A ship speed offset correcting unit is provided for determining a ship speed offset and correcting the ship speed later.

  According to the first aspect of the present invention, when the hull is steered, a turning angular velocity is generated around the azimuth axis, and at the same time, a side slip velocity is generated in the lateral direction of the hull. In order to prevent this, the reference skew angle is obtained, and the feedforward rudder angle is corrected based on the reference skew angle, so that the side slip speed and the reference skew angle can be offset to prevent a channel error. .

  According to the second aspect of the present invention, since the reference direction is the direction along the planned route, the reference position can be obtained by integrating the reference velocity vector obtained from the reference direction. It is also possible to use a reference route determined by the above route instead of the planned route.

  According to the third aspect of the present invention, in order to prevent a channel error due to tidal current, coordinate conversion is performed on the basis of the reference direction in which the tidal current component estimated by the estimator is output by the reference direction generating unit, and the tidal current hull is detected. By calculating the lateral component, determining the corrected tilt angle against the tidal current from the lateral component, and correcting the feedforward rudder angle based on this corrected tilt angle, the lateral tidal component and the corrected tilt that change due to the turn It is possible to cancel the navigation angle and prevent the navigation error.

  According to the present invention as set forth in claim 4, the lateral component of the tidal hull is a reference course obtained by adding a reference heading and a reference heading angle when there is a reference heading angle for offsetting the skid speed. Can be obtained accurately using.

  Since the tidal component is estimated by the estimator of the feedback controller, a reference signal is obtained by adding a corrected oblique angle determined based on this estimated tidal component to the reference direction, and the reference signal and the detection signal are obtained by the orbital channel error calculation unit. Is input to the feedback controller as a trajectory error, a minor loop is created and the control system characteristics change. According to the fifth aspect of the present invention, the correction amount corresponding to the feedback control of the corrected skew angle is corrected to the feedforward steering angle so that the same operation as that including the corrected skew angle is included in the reference signal. By doing so, the generation of minor loops can be prevented.

  According to the sixth aspect of the present invention, the reach, which is the difference between the steering start position and the turning start position hull, is calculated on the predicted hull route from the steering start position to the farthest position in the azimuth direction at the start of turning. An advance that is a distance in the azimuth direction, that is, a so-called turning longitudinal distance is obtained, and the turning radius can be subtracted from the advance so that the advance can be reliably obtained.

  According to the seventh aspect of the present invention, an accurate reach can be obtained by taking the influence of a tidal component into consideration in the reach calculation.

  According to the present invention described in claims 8 and 9, since the ground speed changes due to the change in the bow direction component of the tidal component due to the turn, the specified turn angular velocity corrected according to the change in the ground speed is changed. It is possible to output a reference direction for realizing a trajectory along a planned route having a constant turning radius.

  According to the tenth aspect of the present invention, the ship speed offset can be obtained from the reference azimuth before and after the turn and the estimated tidal current vector, and a channel error caused by the ship speed offset can be prevented.

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

FIG. 1 is an overall block diagram of a marine vessel automatic steering apparatus and an object to be controlled. As described above, the marine vessel automatic steering device 10 is a device that controls the rudder in order to track the hull position on the planned route, and includes a trajectory plan unit 12, a trajectory route error calculation unit 14, a feedback control unit 16, and an addition. And an identifier (not shown) for identifying each parameter. The ship speed U from the planned route and the speed log of the sensors 26 is input to the trajectory planning unit 12 from the guidance system 22, and the trajectory planning unit 12 makes reference signals such as reference direction ψ _R , reference positions x _R , y _R and turning. Sometimes the feedforward steering angle δ _FF is output.

The orbital route error calculation unit 14 receives detection signals from the sensors 26 such as the heading ψ from the gyrocompass and the position (x, y) of the hull from a satellite positioning system (GNSS) such as GPS. The error calculation unit 14 compares the reference azimuth ψ _R , reference positions x _R , y _R and the detection signal to determine the azimuth error ψ _e , position error x _e , y _e (the azimuth error, the position error and the trajectory error. (Also called).

  As shown in FIG. 1, the feedback control unit 16 includes an estimator 18 and a feedback gain unit 20. The azimuth error and position error from the track route error calculation unit 14 are input to the estimator 18. In the estimator 18, the state quantity, position error, and tidal vector of the azimuth error system are estimated from the azimuth error and the position error.

  The planned route given from the guidance system 22 is determined from the start position and the end position in the case of a straight route, and the start position (corresponding to the end position of the straight route) and the end point (turn radius) in the case of a curved route. And the turn angle, which corresponds to the start position of the straight channel). The marine vessel automatic steering device is to cause the hull to track within an allowable error in a straight route and a curved route. The feedback control unit 16 takes charge of the straight route, and the trajectory planning unit 12 takes charge of the curved route.

As shown in FIG. 2, when the planned route of the curved route is input from the guidance system 22, the trajectory planning unit 12 obtains the turning condition, and generates the reference direction ψ _R and the reference angular velocity r _R that match the turning condition. A reference azimuth generating unit 30, a side slip correcting unit 32 for obtaining a reference skew angle β _R corresponding to the turning angular velocity generated by turning the rudder, and a reference course obtained by adding the reference skew angle β _R to the reference azimuth ψ _R An adder 33 that generates θ _R , a reference speed generation unit 34 that generates a reference speed of the hull, a reference position generation unit 36 that generates a reference position by integrating the reference speed of the hull, and a coordinate conversion of the estimated tidal current. A coordinate conversion unit 40 that generates a tidal component in the lateral direction (sway direction) of the hull, a tidal current correction unit 42 that generates a modified oblique angle β _d to counter the tidal current, and a ground speed that corrects the ground speed. a correction unit 44, see the hull azimuth orientation [psi _R + A feedforward steering angle generating section 46 that outputs a feedforward steering angle [delta] _FF for follow without delay to Teruhasu Wataru angle beta _R + modified oblique Kou angle beta _d, feedforward steering angle to correct the feedforward steering angle The correction part 48 and the reach calculating part 50 which calculates the reach which is the distance between a turning start position and a steering start position are provided.

During turning, the feedforward steering angle δ _FF is sent to the steering machine as a commanded steering angle, and the steering machine moves the steering angle in proportion to the commanded steering angle. To do. Along with the generation of the turning angular velocity, a skew angle, that is, a skid speed is generated. To prevent route error due to the side-slip velocity, a reference azimuth ψ reference oblique Kou angle obtained by converting the side-slip velocity to _R beta _R as a reference course theta _R plus by the adder 33, the feedforward steering angle generating including this by performing feedforward control part 46 converts the feedforward steering angle, referenced oblique Kou angle beta _R is canceled and side-slip velocity, the hull route would follow the reference azimuth [psi _R.

Further, in order to prevent a channel error due to tidal currents, the tidal current component estimated in the ground system is converted by the coordinate conversion unit 40, and the corrected oblique navigation angle which is the correction amount of the horizontal direction (sway direction) component of the hull of the tidal current. β _d is obtained by the tidal current correcting unit 42, and the feed forward rudder angle generating unit 46 including the corrected oblique steering angle β _d is converted into a feed forward rudder angle to execute feed forward control, thereby executing the lateral direction of the tidal hull. The (sway direction) component and the corrected skew angle β _d are offset, and the hull route follows the reference direction ψ _R.

The ground speed that determines the hull position is determined from the water speed and the bow direction speed component of the hull converted from the tidal component of the ground system. Since the bow direction velocity component of the tidal hull changes in conjunction with the bearing, the ground speed changes during the turn. In order to realize a turning with a constant radius, when the ground speed changes, the ground speed correcting unit 44 corrects the turning angular speed r ₀ ^* for obtaining the reference direction. As a result, the change in the turning radius due to the ground speed and the correction of the reference angular velocity are canceled out, and the hull route follows a route with a constant radius turn.

  Also, when the hull turns the rudder, the side-slip speed integration is slightly faster than the bow-direction speed, so it moves in the sway direction (this amount is called a kick) and then turns and turns. Move to draw a trajectory. The amount of movement of the hull viewed from the bow direction (surge direction) at the start of turning is called advance, and the distance between the position where the rudder is turned off (steering start position) and the actual turning start position is called reach. Call. When trying to obtain reach, the kick may be smaller than the ship type, and the kick becomes smaller by correcting the skew angle. Therefore, the reach calculation unit 50 obtains a reach from the advance. The reach calculation is performed in advance before the start of the course change, and the turning angle (the amount of course change) is set to 90 degrees or more, preferably about 130 degrees in the state where the tidal current component is applied in advance calculation. Find the expected route and seek Advance. Reach is obtained as Advance minus the turning radius.

Details of the above configuration will be described below.
1. Equation of Motion 1.1 Coordinate System The coordinate system used in the route control system is composed of the following coordinate systems as shown in FIG.
Ground system (XOY): A latitude-longitude coordinate system fixed on the earth, which corresponds to position output (x, y) from GNSS.
・ Hull system (X _B GY _B ): A hull-fixed motion coordinate system that defines the hull motion with the center of gravity of the hull as the origin and the heading as the X _B axis.
Reference system (X _R O _R Y _R ): A moving coordinate system determined from the planned route generated and designated by the guidance system 22.
The rotation polarity of the coordinate system is positive in the right screw direction, and the gravity direction is positive in the Z-axis direction. The coordinate system uses two dimensions, the X axis and the Y axis.

1.2 Hull equation of motion In order to determine the hull model to be controlled, a hull equation of motion is derived. Since the equation of motion of the hull deals with the movement in the lateral direction and around the azimuth axis, excluding the forward direction,

Is used. Here M _x, M _y, respectively x, the mass containing additional mass in the y-direction, I _z is a moment of inertia including the additional moment of inertia about the z-axis, Y, fluid force of each N is the y direction, Indicates the fluid moment about the z-axis, where the suffix means the corresponding variable. Variables U, v, r, and δ represent forward speed, side flow (side slip) speed, turning (turning) angular speed, and steering angle, respectively. Organizing the above formula

になり、ラプラス変換すると（ｓ はラプラス演算子を示す）

And Laplace transform (s is Laplace operator)

のようになる。ここで、横滑り速度と旋回角速度とが舵角を入力とした関係で結ばれる。(5)式を整理して、舵加速度δ^・・(t)≒０とし、

become that way. Here, the skid speed and the turning angular speed are connected with the steering angle as an input. Rearranging equation (5), the rudder acceleration δ ^{・ ・} (t) ≒ 0,

を得る。ここで、

Get. here,

とおいている。

I keep it.

From equation (6), the equation of motion of the side slip velocity in the lateral direction (sway) and the turning angular velocity around the yaw axis are the same and only the input coefficient depending on the steering angle is different. By turning the rudder, the hull characteristics generate a turning angular velocity around the azimuth axis, and at the same time, generate a skid velocity due to the reaction force against water in the lateral direction of the hull. Those in (6), the s ² Section for practical standpoint impact of s ² term can be ignored. Then, equation (6) becomes

になる。ここで、

become. here,

であり、Ｔ_s = Ｔ₁＋Ｔ₂である。ここでＫ_s は旋回力ゲイン、Ｋ_v は横滑りゲイン、Ｔ_s3、Ｔ_v3は時定数である。

And T _s = T ₁ + T ₂ . Here, K _s is a turning force gain, K _v is a skid gain, and T _s3 and T _v3 are time constants.

  In addition, since the ship automatic steering device inputs the control amount through the rudder angle, the control variable may be more convenient in angle units.

を用いて横滑り速度ｖを斜航角βに変換すると、

Is used to convert the skid speed v to the skew angle β,

として導出される。ここで、Ｋ_β は横滑り角ゲインまたは斜航角ゲイン（旋回力ゲインＫ_s と異符号となる）で、Ｔ_β3は時定数で

As derived. Here, K _β is a side slip angle gain or a skew angle gain (which has a different sign from the turning force gain K _s ), and T _β3 is a time constant.

を示す。

Indicates.

  Since the side slip velocity v and the skew angle β of the hull model have a first-order lag element in common with the turning angular velocity r,

become. From this, it can be seen that v and β are approximately proportional to r by gains K _v / K _s and K _β / K _s , respectively. Since there is a relationship of T _v3 > T _β3 and T _s3 > T _β3 , T _v3 and T _β3 can be omitted _{depending on} the hull, while K _v and K _β are essential parameters.

  Equations (1) and (2) take into account first-order terms in Taylor expansion, but in order to deal with large turning angles and turning angular velocities, it is necessary to take into account non-linear terms. In that case, the equation of motion of equation (9) is

とするとよい。ここでα_sは非線形係数であり、ゲイン、時定数と同様前記同定器によって与えられる。

It is good to do. Here, α _s is a nonlinear coefficient, and is given by the identifier as well as the gain and time constant.

1.3 Ground speed and ground position The position of the hull is defined by the ground system and can be obtained by integrating the ground speed from the hull motion and tidal velocity. The hull speed is the water speed and the tidal current speed is the ground speed.

When the hull motion takes the rudder angle δ, an angular velocity r = ψ ^· is generated, but at the same time, a lateral flow velocity v = y ^· is also generated. This will be described with reference to FIG. As shown in the figure, when turning in a steady state or when the reference system is coincident with the tangent direction, the ship system is balanced by inclining to the tangential direction by a skew angle β. At this time, the ground speed component of the hull speed is

になる。ここでｕ_x，ｖ_y は対地系のそれぞれ北向き，東向きの船体速度、ｕ，ｖは船体系の速度を示す。船体速度と斜航角との関係は、

become. Here u _x, v _y are each facing north of the ground system, the hull speed of eastward, u, v indicates the speed of the hull system. The relationship between hull speed and skew angle is

を用いる。
これより、対地系の速度は、船体速度と潮流速度との和になるから、

Is used.
From this, the speed of the ground system is the sum of the hull speed and the tidal current speed,

になる。ここでｘ、ｙは船体位置でそれぞれ北向き、東向きを示す。なおｄ_x，ｄ_y は風が船体の上部構造物を押すことによる速度成分も含まれているとする。
位置と方位とはそれぞれ速度ｘ^・、ｙ^・と角速度ｒとを積分して

become. Here, x and y indicate the north direction and the east direction, respectively, in the hull position. Note d _x, d _y is assumed to be included velocity component due to the wind pushes the upper structure of the ship.
The position and direction are obtained by integrating the velocity x ^· , y ^· and the angular velocity r, respectively.

得る。ここで（０）は初期値を意味する。

obtain. Here, (0) means an initial value.

2 Turning Trajectory 2.1 Reference Orientation and Reference Angular Velocity The ship orientation ψ can be made to follow the reference orientation ψ _R by using the direction change control system shown in Patent Documents 1 and 2 and Non-Patent Document 1. .

The signals input to the trajectory planning unit 12 are the planned route and ship speed U, the outputs are the reference direction ψ _R , the reference positions x _R and y _R , and the feedforward steering angle δ _FF .

When the planned route of the curved route is input from the guidance system 22, the reference direction generation unit 30 obtains the turning radius R and the change amount (turning angle) ψ ₀ that are turning conditions. From this turning condition, the designated angular velocity r ₀ is determined. Further, as other turning conditions, hull parameters T _s , K _s , T _S3 , T _3β , C _β = K _β / K _s (these hull parameters are default values or are turned by an identifier). The initial angular acceleration C _1a of the hull motion, the initial angular velocity C _2a , the maximum rudder angle δ ₀ , and the upper limit values δ _RH ^· and δ _RL ^{· of} the rudder speed.

Then, a reference orientation that satisfies this turning condition is calculated. In this calculation, the trajectory calculation unit proposed in Patent Document 1 or Patent Document 2 can be used, and the trajectory calculation unit sets the reference direction to the desired amount of change of the ship in the acceleration mode, constant speed mode, and The speed is divided into deceleration modes and output sequentially in time series. At that time, the maximum rudder speed is determined according to the amount of change of needle, and the rudder speed of the feedforward rudder angle corresponding to the calculated reference azimuth is determined. The reference azimuth of each mode is calculated so as not to exceed the maximum steering speed, and the reference azimuth ψ _R and the reference angular velocity r _R (r _R = sψ _R (s)) are output. Specifically, it can be performed as follows.

  The second-order differentiation, first-order differentiation, and reference orientation of the reference orientation in the acceleration mode can be expressed as follows.

  The second-order differentiation, first-order differentiation, and reference orientation of the reference orientation in the constant velocity mode can be expressed as follows.

  The second-order differentiation, first-order differentiation, and reference orientation of the reference direction in the deceleration mode can be expressed as follows.

T _a , T _v , and T _d represent acceleration time, constant speed time, and deceleration time, respectively, and considering the continuity between the modes,

の関係が成り立つ。

The relationship holds.

Here, the ratio between the constant speed time T _v (or T _v = T _a if the initial angular acceleration C _1a and the initial angular speed C _2a are zero) and the deceleration time T _d is defined as a constant deceleration ratio R _vd . That is,

とする。

And

The angular velocity r ₀ (= T _a β _a / 6) = U / R at the constant speed is specified, and if the acceleration time T _a , acceleration constant β _a and R _vd are determined, each coefficient is determined and each mode is determined. it can be determined reference direction [psi _R in.

Thereafter, if the initial angular acceleration C _1a and the initial angular velocity C _2a are zero, the relationship between the acceleration time _Ta , the acceleration constant β _a, and the maximum steering speed δ _R ^·

となる。ここで、Ｃ_Rは舵定数と呼ぶ。加速モード、等速モード、減速モードの全モードの変針量ψ₀は、

It becomes. Here, C _R is referred to as a rudder constant. Needle change amount ψ _{0 in} all modes of acceleration mode, constant speed mode, deceleration mode is

となり、書き直すと、

And then rewrite

になる。Ｒ_vdは、一定値とし、等速モード時の旋回角速度が指定旋回角速度に可能な限り近くなる値が選択されるとよい。

become. R _vd may be a constant value, and a value that makes the turning angular velocity in the constant speed mode as close as possible to the designated turning angular velocity may be selected.

Further, the maximum steering speed is determined from the amount of change of the needle, and based on the calculated reference direction, the steering speed of the feedforward steering angle corresponding thereto is not exceeded and does not exceed the determined maximum steering speed. In this manner, T _a and β _a are determined, and the reference orientation of each mode is calculated.

In summary, the reference orientation ψ _R proposed in Patent Document 2 is specifically:

と表すことができる。ここで、係数Ｒ₅、Ｒ₄、Ｒ₃、Ｒ₂、Ｒ₁は、次の表のように表すことができる。

It can be expressed as. Here, the coefficients R ₅ , R ₄ , R ₃ , R ₂ and R ₁ can be expressed as shown in the following table.

参照方位発生部３０は、逐次計算される参照方位ψ_R及びその一次微分である参照角速度ｒ_Rを出力する。

The reference azimuth generating unit 30 outputs a reference azimuth ψ _R that is sequentially calculated and a reference angular velocity r _R that is a first derivative thereof.

2.2 Feedforward rudder angle correction FIG. 5 shows an outline of feedforward control in a basic turning control system. In the figure, G _FB represents the gain of the feedback control unit 16, P represents the hull model, and P ^-1 represents the reverse hull model. At this time, the transfer characteristic from the reference direction ψ _R to the bow direction ψ is

になる。
船体モデルＰは、(9)式から、

become.
The hull model P is obtained from equation (9)

となる。ここでＰ⁻¹ のパラメータ不確かさは無視できるほど小さいとする。これより、船首方位ψを参照方位ψ_R に遅れなく追従する。

It becomes. Here, it is assumed that the parameter uncertainty of P ⁻¹ is small enough to be ignored. Thus, the heading azimuth ψ follows the reference azimuth ψ _R without delay.

Thus, feedforward steering angle generating section 46 with respect to the reference direction [psi _R, so as to have a transfer characteristic of P ^-1, obtaining the feedforward steering angle.

Further, the feedforward rudder angle generating unit 46 obtains a feedforward rudder angle corresponding to the ship's tilt angle and the tidal current angle, in addition to the reference direction, in order to cause the planned route to track the hull path. Here, as shown by the equation (16), the reference tilt angle β _R equivalent to the ship's tilt angle is obtained independently of the closed loop system based on the reference direction ψ _R or the reference angular velocity r _R. as shown in FIG. 6 (a), by adding the [psi _R, it is possible to cancel the influence of the oblique Wataru angle of the hull. However, the tidal angle β _d of the tidal current can be obtained from the estimated tidal current components d _x ^ and d _y ^ obtained from the estimator 18 in the feedback control unit 16 of the closed loop system. Therefore, as shown in FIG. When added to the bearing, a minor loop is formed and the control system characteristics change.

Therefore, since β _d cannot be returned to the front, as shown in FIG. 6 (b), it is equivalent to the case where the feed forward rudder angle correcting unit 48 corrects the rear and corrects the front in FIG. 6 (a). Make sure that In the figure, δ _ψR , d _βR , and d _βd are feedforward steering angles and correspond to ψ _R , β _R , and β _d , respectively.
First, the feed-forward rudder angle corresponding to the tidal angle β _d is

により得られる．ここでｓはラプラス演算子を、Ｐ^-1 _ψは(23)式で表される船体モデルである。β_d を前方に帰還した場合の軌道航路誤差演算部１４で求まる偏差は、

Is obtained by Here, s is a Laplace operator, and P ⁻¹ _ψ is a hull model represented by the equation (23). The deviation obtained by the orbital route error calculation unit 14 when β _d is fed back is:

になる。ここでψ_e ＝ψ_R−ψである。潮流の斜航角b_dを含めたフィードバック舵角は、

become. Here, ψ _e = ψ _R −ψ. The feedback steering angle including the tidal angle b _d of the tidal current is

なる。尚、フィードバックゲインＧ_FBは、Ｇ_FB＝Ｋ_P＋Ｋ_Dsである。
よってβ_d の修正はフィードフォワード舵角δ_βd とフィードバック舵角

Become. The feedback gain G _FB is G _FB = K _P + K _D s.
Therefore, β _d is corrected by _{adjusting the} feedforward steering angle δ _βd and the feedback steering angle.

とによる修正を実施すれば、前方のψ_R に帰還した場合と同等の応答特性、すなわち

If the correction by is performed, the response characteristic equivalent to the case of returning to the front ψ _R , that is,

を得ることができる。

Can be obtained.

Feedforward steering angle correction unit 48, to the feed forward steering angle obtained by the feedforward steering angle generating section 46, correct the multiplied by the feedback gain G _FB against tide oblique Kou angle beta _d feedback steering Add and correct as a corner.

2.3 Reference route by reference direction The reference speed generated by the reference speed generator 34 is

から得られる。ここでｕ_R，ｖ_R は対地系参照速度でそれぞれｘ，ｙ方向を、ｔは時間を、ψ_Rは参照方位を、Ｕは一定船速を示す。これより、参照位置発生部３６で求まる参照航路は、(28)、(29)式を積分することにより、

Obtained from. Here, u _R and v _R are ground system reference speeds in the x and y directions, t is time, ψ _R is the reference direction, and U is a constant ship speed. Thus, the reference route obtained by the reference position generator 36 is obtained by integrating the equations (28) and (29).

become. Here, x _R and y _R are the ground reference channel in the x and y directions, respectively, r _R is the reference turning angular velocity and r _R = ψ _R ^· Where c _x and c _y are the initial values of x and y, respectively, and R 1 = U / r _R is the turning radius. If you put a x _R = y _R = 0 when the initial conditions t = 0

を得る。よって参照航路は

Get. So the reference route is

になる。上式より

become. From the above formula

を得る。よって参照方位による参照速度を積分した参照航路は中心が(０，Ｒ) で、円状の軌道を描く。これより参照航路を計画航路の代わりに利用することが可能になる。

Get. Therefore, the reference route obtained by integrating the reference velocity based on the reference direction has a center of (0, R) and draws a circular orbit. This makes it possible to use the reference route instead of the planned route.

2.4 Side slip speed of the hull The effect of the side slip angle or the tilt angle obtained by converting the side slip speed of the hull on the constant radius turning will be described, and the action of the side slip correcting unit 32 will be described. If the characteristics of the hull are known, the skid speed and the skew angle are replaced with the reference direction.

Referring oblique Kou angle beta _R is (16) than, for simplicity, r _R ^· = 0, the time constant T _s3, T _.beta.3 is when _{zero, β R = C β r R} , C β = K β / K _s .
The reference speed including the reference skew angle is

になる。ここでｕ_Rβ ，ｖ_Rβ は参照斜航角を含んだ対地系参照速度でそれぞれｘ，ｙ方向を示す。これより参照航路は、

become. Here, u _Rβ and v _Rβ are ground system reference velocities including the reference skew angle and indicate the x and y directions, respectively. From this, the reference route is

になる。ここでｘ_Rβ，ｙ_Rβ は対地系参照航路でそれぞれｘ，ｙ方向を、ｃ_xβ，ｃ_yβ はそれぞれ初期値を示す。初期条件ｔ＝０のときｘ_Rβ ＝ｙ_Rβ ＝０と置けば

become. Here, x _Rβ and y _Rβ are respectively the x and y directions on the ground system reference route, and c _xβ and _cyβ are initial values. When initial condition t = 0, if x _Rβ = y _Rβ = 0

を得る。よって参照航路は

Get. So the reference route is

になるから、参照斜航角を含まない参照航路を用いると

Therefore, if you use a reference route that does not include the reference skew angle,

になる。ｘ_Rβ，ｙ_Rβ の軌跡は上式より、ｘ_R，ｙ_Rの円状軌跡を−β_Rだけ原点周りに回転させたものになる。

become. The trajectories of x _Rβ and y _Rβ are obtained by rotating the circular trajectories of x _R and y _R around the origin by −β _R from the above equation.

Next, the skew angle characteristics will be described with reference to FIG. In the figure, a route in which a thin circle with a center (0, R) radius R is set in the ground coordinate system XY is shown, and a rotational coordinate system of −β _R is represented by ξη. The thick circle is rotated around the origin by -β over the thin circle. Although the route was planned on a thin line circle, it will track on a thick line circle because of the skew angle. At this time, with regard to the thick line route, 1. The radius is the same as the narrow route, but the center is

に変化する
２． 軌跡は一度旋回方向と反対方向に移動し、その後旋回し始める。その移動量は

Changes to 2. The trajectory once moves in the direction opposite to the turning direction and then starts to turn. The amount of movement is

になる。さらにｘの最大位置はｘ_β ＋Ｒ＝Ｒ(sinβ_R＋１) になる
３． 対地系方位または針路φ_Rはψ_Rからξη系回転角β_R だけ遅れている。すなわち

become. Further, the maximum position of x is x _β + R = R (sin _{β R} +1) 3. The ground direction or course φ _R is delayed from ψ _R by the ξη system rotation angle β _R. Ie

になり、斜航角により回転した円の接線方向を向いている
なる特性をもつ。この斜航角特性から、船速一定の旋回に関する移動量ｘ_Rβ，ｙ_Rβ について調べる。β_R(＜３０o)を微小角とする。

And has a characteristic that it is directed to the tangential direction of the circle rotated by the skew angle. From the skew angle characteristics, the movement amounts x _Rβ and y _Rβ relating to turning at a constant ship speed are examined. _Let β _R (<30 °) be a small angle.

になる。ここで、β_R≒Ｃ_βｒ_R、Ｃ_β＝Ｋ_β／Ｋ_s、ｒ_R＝Ｕ／Ｒである。

become. Here, β _R ≈C _β r _R , C _β = K _β / K _s, r _R = U / R.

From this, it can be seen that x _Rβ is obtained by multiplying C _K by U and is independent of R and r _R. On the other hand, y _Rβ is obtained by dividing the square of x _Rβ by 2R, and is related to R and r _R and is proportional to Ur _R.

And numerical _{example, C β = 30 [s]} , U = 20 [knot], when R = 1500 in _{[m], x Rβ = 30} × 20 × 0.5144 = 308.6 [m], y Rβ = -31.75 [ m]. The radius that makes y _Rβ −50 [m] or less is R <952.6 [m].

  Now, since the influence of the hull's oblique angle on the route has been confirmed, from the above characteristics, in order to match the hull route with the reference route, the reference course with the reference oblique angle added to the reference direction in reverse is used. I know it ’s good. Ie

になる。ここでθ_Rは参照針路を示す。上式を用いることによって、

become. Here, θ _R indicates a reference course. By using the above formula,

になり、船体航路は参照航路つまり円状軌跡に描く。

The hull route is drawn as a reference route, that is, a circular trajectory.

The side slip correction unit 32 generates a skew angle β _R from the reference angular velocity r _R output from the reference bearing generation unit 30 using the relationship of the equation (16), and feeds it to implement the corrected skew angle. The forward rudder angle generation unit 46 sets the feed forward rudder angle δ _βR corresponding to the skew angle due to the side slip by the transmission characteristic represented by the reverse hull model P ^-1 in the same manner as represented by the equation (24). Ask. However, calculation of the feedforward steering angle [delta] _{[beta] R} is, after adding the reference azimuth [psi _R swash Kou angle beta _R, feedforward steering angle _δ ψR + δ by the transmission characteristic expressed by reverse hull model P ^-1 It is also possible to obtain _βR .

2.5 Correction of tidal component The tidal component applied in the sway direction of the hull is corrected using the ground tidal component estimated by the estimator 18 of the feedback control unit 16.

The coordinate conversion unit 40 converts the estimated values d _x ^{^} and d _y ^{^} of the tidal current components of the ground system obtained from the estimator 18 into tidal current components of the ship system. That is,

になる。ここで、θ_Rは(49)式で表される参照針路である。

become. Here, θ _R is a reference course represented by equation (49).

As a result, the tidal current correction unit 42 calculates the corrected oblique navigation angle in the sway direction to reduce the channel error due to the tidal component v _d in the sway direction.

から求める。ここで

Ask from. here

を示す。

Indicates.

Therefore, in order to implement the corrected skew angle, the feed forward rudder angle generator 46 _{obtains the} feed forward rudder angle δ _βd corresponding to the corrected skew angle by the equation (24), and the feed forward rudder angle corrector 48 , (26) is used to obtain a correction value. Derivation of the first and second derivative values of β _d required for this calculation can also be obtained by numerical differentiation, but because the rudder angle variation is large due to the influence of sampling time, the tidal component is almost constant. It is preferable to use an analytical differential that is an approximate solution of β _x ^· , β _y ^· = 0 as values.

  That is, by analysis,

として得られる。ここで、

As obtained. here,

を示す。ψ_R，ｒ_R，ｒ_R ^・は参照方位発生部３０から得られる。

Indicates. ψ _R , r _R , r _R ^· are obtained from the reference orientation generator 30.

2.6 Ground Speed Correction The ground speed correction unit 44 corrects the turning angular speed by changing the ground speed.

  The hull route is obtained by integrating the ground speed. The hull speed is composed of speed against water (log ship speed) and tidal current (including wind component).

First, from the tidal component u _d in the surge direction obtained by the coordinate conversion unit 40 (see equation (51)), the ground speed U ^* taking into account the tidal current is calculated.

Ask from. Note that here, U≈u, the ship speed and the tidal current speed during the course change are set to substantially constant values, and u _d ≈u _d ^ is used from the equation (51). To keep the turning radius constant, necessary to modify the turning angular velocity in response to U ^* which varies by [psi _R occurs. Ie

になる。ここで、ｒ₀ ^*は軌道計画の指定旋回角速度（等速時の角速度）を、Ｒは計画航路の旋回半径を、SetΔＵは設定値（例えば5%）を、Ｕ₀ ^*は前回の値を示す。

become. Here, r ₀ ^* is the specified turning angular velocity (angular velocity at constant speed) of the trajectory plan, R is the turning radius of the planned route, SetΔU is the set value (for example, 5%), and U ₀ ^* is the previous value. Show.

The ground speed correction unit 44 detects a change in U ^* due to a change in the tidal component u _d ^ sequentially output from the coordinate conversion unit 40, and if the change amount exceeds the set value based on the equation (60). , R ₀ ^* is updated and output to the reference orientation generator 30.

When r ₀ ^* is updated, the reference azimuth generator 30 reconstructs and outputs the reference azimuth ψ _R and the reference angular velocity r _R that is the first derivative thereof so as to satisfy r ₀ ^* . The amount of specified change at that time is the amount obtained by subtracting the direction already changed.

になる。ここでψ₀ ^*は指定変針量（旋回角）を、ψ₀ は計画航路の指定変針量（旋回角）を、Δψ'_Rはｒ₀ ^*が更新されるまでの変針量（旋回角）を示す。

become. Here, ψ ₀ ^* is the designated change amount (turning angle), ψ ₀ is the designated change amount (turning angle) of the planned route, and Δψ ' _R is the change amount (turning angle) until r ₀ ^* is updated. Show.

2.7 Reach Calculation In the present invention, reach calculation is one of the features, and three corrections, hull inclination angle, tidal inclination angle, and speed correction (angular speed correction) are all included. Implemented by open loop using feedforward control. Here, there is no parameter uncertainty.

  When feedforward control is not used, a reference signal is given to a closed loop system that combines a hull equation of motion and a control system, and numerical calculation is performed. This is because a sway direction error occurs when tidal current is applied, so a control system is required.

On the other hand, when feedforward control is used, it is not necessary to use a closed loop system. Since the influence of the tidal component is canceled by the tidal angle and speed correction, there is no sway direction error. Therefore, the control system becomes unnecessary, and the configuration is simplified as shown in FIG. In FIG. 8, when the planned route from the guidance system 22 is input, the reach calculation unit 50 obtains the turning condition and turns the turning radius of the turning condition in the second coordinate system in which the turning start direction is converted to the north. A reference azimuth generating unit 52 that generates a reference azimuth ψ _R and a reference angular velocity r _R that match a predetermined turning angle, and a side slip correction unit that obtains a reference skew angle β _R corresponding to the turning angular velocity generated by turning the rudder. 54, a front coordinate conversion unit 62 that converts the coordinate of the estimated tidal current and transforms the direction of the turning start into the north direction, and converts the direction into the north direction, and the horizontal direction of the hull from the tidal component of the second coordinate system A coordinate conversion unit 64 that generates a tide component in the (sway direction), a tide correction unit 66 that generates a corrected oblique angle β _d that faces the tide, a ground speed correction unit 68 that corrects the ground speed, and a reference orientation and [psi _R and correction oblique Kou angle beta _d An adder 70 for calculating, a hull velocity generating unit 72 for generating a hull velocity component in the second coordinate system, an adder 74 for adding a tidal velocity component in the second coordinate system, and integrating the added velocity components for prediction A hull position generation unit 76 for obtaining a hull route and a reach output unit 78 for obtaining an advance from the hull position generation unit 76 and obtaining a reach from the advance are provided. The hull speed generator 72, the adder 74, and the hull position generator 76 constitute a hull route generator.

If the reach calculation is performed using the feed-forward steering angle instead of the reference signal, if the tidal component is not applied, it almost matches the case of the reference signal, but if the tidal component is applied, a sway direction error occurs. Therefore, a control system is required. Accordingly, the reach calculation is achieved by the reference signal (ψ _R , r _R ) and the correction signal (β _R , β _d ) based on the feedforward control.

  Reach is the distance traveled in the bow direction from the start of steering for turning until the hull moves in the turning direction, and is the distance between the Wheel Over Point (WOP) and the turning start position or the center of the circle .

The reach calculation is performed before turning, and the turning trajectory is calculated numerically. The procedure is shown below.
The planned route is determined by three way-points (WP ₁ , WP ₂ , WP ₃ ) and a turning radius R as shown in FIG. Since the calculation is complicated in this coordinate relationship, the reach calculation can be simplified by always fixing the turning start direction ψ _R1 to the north. The planned route of the XOY system is considered by converting the coordinates into the planned route of the X′O′Y ′ system (also referred to as the second coordinate system) as shown in FIG. At the same time, the turning angle (the amount of change of needle) is set to a predetermined turning angle of 90 degrees or more, for example, 130 degrees, regardless of the turning angle by the planned route.
At that time, the azimuth angle of the tidal component is from ψ _d

に変換される。
Ｘ’Ｏ’Ｙ’ 系の速度成分ｘ'^・、ｙ'^・は(20)式を参考にすると

Is converted to
X'O'Y 'system velocity component x of' ^·, y ^'· is a Sankounisuru the formula (20)

になる。ここでｕ_x ^・、ｖ_y ^・はＸ’Ｏ’Ｙ’ 系の船体速度成分で、ｄ_x ^・、ｄ_y ^・はＸ’Ｏ’Ｙ’ 系の潮流速度成分で、それぞれ

become. Here u _x ^·, v _y ^· the 'hull speed component of the system, d _x ^·, d _y ^· is X'O'Y'X'O'Y in tidal velocity component of the system, respectively

を示す。

Indicates.

The reference azimuth generating unit 52 has the same configuration as that of the reference azimuth generating unit 30, but outputs the reference signals ψ _R and r _R in the X′O′Y ′ system in time series. The ground speed correction unit 68 has the same configuration as that of the ground speed correction unit 44, and appropriately supplies an updated designated turning angular speed in which a change in the ground speed is corrected to the reference direction generation unit 52.

The side slip correction unit 54 outputs a correction signal β _R that is a reference tilt angle of the hull in the X′O′Y ′ system in time series. The adder 55 adds the reference direction ψ _R and the correction signal β _R.

From the estimated tidal velocity components d _x ^, _dy ^ and the turning start direction ψ _R1 , the preceding coordinate conversion unit 62 calculates _X from the d _x ^ ≈d _x , d _y ^ ≈d _y based on the equation (64). Based on the reference course θ _R , the coordinate conversion unit 64 converts the tide velocity components u _d ^ and v _d ^ of the ship system into the tide velocity components d ' _x and d' _y of the 'O'Y' system. The tidal current correction unit 66 outputs a correction signal β _d which is the tidal current oblique angle.

The adder 70 adds the reference bearing ψ _R and the correction signal β _d, and the hull velocity generator 72 obtains the velocity component in the X′O′Y ′ system based on the equation (63). Note that the hull angle β is not included because it is offset by the correction signal β _R. To the hull velocity component from the hull velocity generator 72, the adder 74 adds the tidal velocity component in the X'O'Y 'system.
From this, the hull position generating unit 76 uses the X'O'Y 'series of hull routes x', y ',

Ask from. At this time, τ is a change time for passing the point P2 where the x ′ coordinate has the maximum value. The change time is the acceleration time T _{a in} the acceleration mode, the constant speed time T _{v in the} constant speed mode, and the deceleration time T in the deceleration mode. _{It is} assumed that τ ≧ T _a + T _v exceeding the constant speed time of _d .
The reach output unit 78 obtains the y ′ coordinate when the x ′ coordinate takes the maximum value from the x′y ′. This y ′ coordinate is an advance. Then, the reach is obtained by subtracting the turning radius R from the advance.
That is, reach is obtained from the following equation.

  The calculation by the reach calculation unit 50 is executed after the planned route is established, but it is desirable to calculate again after approaching the vicinity of the WOP (for example, within the range of 3L to 5L, L is the captain). This is to cope with changes in ship speed and tidal current.

2.8 Ship speed offset The ship speed, which is the water speed, is obtained from the speed log of the sensors, but the speed log has a bias error and an offset. When there is this ship speed offset, no route error occurs because the ship speed offset is handled as a tidal component when straight, but a route error occurs because of the offset included in the tidal component when turning. As a numerical example, if the offset is + 10% of the ship speed of 20 kt when there is no tidal current, the error will be from -5 m to -100 m. This substantially corresponds to a state where a tidal current of 2 kt is applied. Therefore, the ship speed offset correction part 80 (refer FIG. 2) which removes this offset is further provided.

First, the characteristics of ship speed offset are examined.
The position error and direction error (route error) obtained by the orbital route error calculation unit 14 are the position error and the direction error of the ship system with respect to the reference system.

become. Here ψ, x, y is a heading and ground _{position, ψ R, x R, y} R and is referred to as a reference orientation _{position, ψ e, x e, y} e , respectively the azimuth error and the route error Show. x _e and y _e correspond to the distances from the hull position G to the Y _R and X _R axes of the reference system, respectively.
The speed error due to the ship system is derived from Eqs. (67) and (20).

になる。潮流速度による速度誤差は対地系成分を参照系成分に変換すると

become. The velocity error due to the tidal velocity is converted from the ground system component to the reference system component.

になる。ここでｕ_d，ｖ_d は参照系の潮流速度成分を、ｄ_x，ｄ_y は対地系の潮流速度成分をそれぞれ示す。よって速度誤差は

become. Here, u _d and v _d indicate tidal current velocity components of the reference system, and d _x and d _y indicate tidal current velocity components of the ground system. So the speed error is

で与えられる。ここで、ｕ_d，ｖ_dにログオフセットが含まれるとして、

Given in. Here, assuming that log offset is included in u _d and v _d ,

を示す。ここで、Ｕは船速を、Ｕ_oはログオフセットを示す。(71)式を(70)式に代入すると、

Indicates. Here, U represents the ship speed and U _o represents the log offset. Substituting equation (71) into equation (70),

Get. From equation (72)
The offset appears only at x _e ^· and is independent of orientation.
・ Tidal currents appear at x _e ^・ , y _e ^・ and are linked to coordinate transformation of direction.
Since ψ _{R is} constant when straight, (−U _o + u _d ) is constant.
And swing before and after, u _d is changed.
You can see the characteristics. From these characteristics, it is understood that the ship speed offset U _o can be obtained from the estimated tidal current before and after the turn if U _o , d _x and _dy are substantially constant before and after the turn. d _x and _dy are constant, but change in x _e ^· and y _e ^· because the influence is given through ψ _R. Conversely, U _o is constant at x _e ^· , but in the ground system, the influence is exerted via ψ _R. This U _o, d _x, to use the nature of the d _y.
Again, from equation (68) and equation (70), if the tilt angle and skid speed are 0,

となる。ここで、横滑り速度ｖ＝０とし、ψ_e≒０とした。従って、速度誤差の推定値の推定誤差は、

It becomes. Here, the skid speed v = 0 and ψ _e ≈0. Therefore, the estimated error of the estimated speed error is

となる。ここで、Ｕ_oψ_e≒０として省き、推定誤差をゼロとして定常値を求めると、

It becomes. Here, when U _o ψ _e ≈0 is omitted, and the estimation error is zero, the steady value is obtained.

になる。(78)式より潮流推定値はＵ_oによる誤差を持ち、方位により変化することが分かる。

become. (78) power flow estimate from equation has an error due to U _o, it can be seen to vary by orientation.

Referring to FIG. 9A, assuming that the directions before and after the turn are ψ _R1 and ψ _R2 , respectively,

が得られる。これより

Is obtained. Than this

を得る。また、ψ_R1,ψ_R2により、
cosψ_Ｒ1 ＝ cosψ_Ｒ2 あるいは sinψ_R1 ＝sinψ_Ｒ2
の場合が生じる。この関係にならないことに注意すれば、Ｕ₀ は

Get. In addition, by ψ _R1 and ψ _R2 ,
cosψ _R1 = cosψ _R2 or sinψ _R1 = sinψ _R2
This happens. Note that this is not the case, U ₀ is

より求まる。潮流値をＵ₀ によって校正すると、

More. When the tidal current value is calibrated by U ₀ ,

になる。ｄ_x2^,ｄ_y2^は現在の値である。

become. d _x2 ^ and d _y2 ^ are current values.

Therefore, the ship speed offset correcting unit 80 obtains U ₀ in the equation (82), corrects the equation (83) with respect to the estimated tidal current, and also applies −U ₀ to the signal (U + U ₀ ) from the log speed. Is added. Thus, the influence on the channel error due to the offset U ₀ is reduced.

The calculation of the boat speed offset by the boat speed offset correcting unit 80 is performed at a point where one turn is completed, P4 in FIG. 9A. The tidal current estimation by the estimator 18 is performed between P ₀ and WOP and between WP ₂ and P ₄ in FIG. 9A, and the ship speed offset correction unit 80 performs correction at the point P _4. Therefore, the tidal current estimation component and the ship speed are corrected. During the course change from WOP to WP ₂ , no new correction is performed by the ship speed offset correction unit 80, and calculation is performed using the tidal current estimation component and the ship speed that have been corrected previously.

2.9 Numerical Calculation Example The performance of the turning operation of the marine vessel automatic steering apparatus configured as described above is verified by simulation.
Hull parameters: U = 20 [knot], K _s = 0.027 [1 / s], K _v = −100 K _s [m / deg], K _β = −K _v / U
T _s = 17.5 [s], T _s3 = 0.1 [s], T _β3 = 0.03 [s], T _β3 = 0.03 [s]
Sensor resolution: Speed 0.1 [knot], Direction 0.1 [deg], Position 1.852 [m] = 0.001 [arc min], No ship speed offset Planned route: Initial direction ψ _R1 = 40 [deg], Final direction ψ _R2 = 140 [deg], distance from the origin Dist = 4 [NM], radius R = 1 [NM], turning angle ψ ₀ = 100 [deg], turning angular velocity r ₀ = 19.1 [deg / min] Equivalent disturbance: tidal current U _d = 0, 5 [knot], direction is described separately, rudder angle offset δ _o = 0, no wave Simulation results: Hull skid velocity v _R and tilt angle β _R determined from simulation conditions, maximum tidal current The navigation angle β _dmax is as follows.

である。

It is.

FIG. 10 shows the reference direction ψ _R , the reference turning angular velocity r _R , the reference turning angular acceleration dr _R / dt, and the feedforward steering angle δ _FF that are reference signals at that time.
The simulation results are summarized in the following table.

   In the figure, non-correction means no correction at all, SS corrects the side-slip speed with the reference tilt angle, CS corrects the tidal current corrected tilt angle, and SC corrects the ground speed. Represents that.

In the captions in the figure, (a) shows the Reach calculation, (b) shows the route trajectory, and in each figure (b), the STW shows the speed over the ground and the STW shows the speed through the water. means. From the results, 1. From Table 2, the reach is almost 100 [m], the shorter the better. Since the moving distance of the acceleration time in the reference direction is T _a × U = 19 × 10.3 = 195.5 [m] (T _a = 19 [s] from FIG. 10), the vehicle is turning from the middle of the acceleration mode.
2. From FIG. 11, the correction amount of the channel error due to β _R is 100 [m]. If not corrected, reach reaches 200 [m].
3. By SS and SS + CS in FIG. 12, the correction of the tilt angle of the tidal component is 0.3 [NM].
4). According to SS + CS and SS + CS + SC in FIG. 13, the speed correction amount of the tidal component becomes an effect of 0.2 [NM].
5. With the SS and SS + CS + SC in FIG. 13, the correction of the tilt angle and speed correction of the tidal current component is 0.45 [NM].
Was confirmed. Therefore, it was verified that the present control system according to the present invention has the effect of each correction.

(A) is a block diagram showing the whole structure of the ship automatic steering device by this invention, (b) is a block diagram showing the structure of a feedback control part. It is a block diagram showing the structure of the track | orbit plan part of FIG. It is explanatory drawing showing the coordinate system used with a route control system. It is explanatory drawing showing the transverse flow speed which generate | occur | produces when taking a rudder. (A) is a block diagram which shows the outline | summary of the feedforward control in a turning control system, (b) is a block diagram which shows the structure of the feedback control part in (a). (A) is a block diagram showing that a minor loop is formed when the tidal current is added to the reference direction, and (b) is a feed without adding the tidal angle to the reference direction. It is a block diagram corresponding to this invention which shows comprising similarly to (a) by a forward steering angle correction part. It is a figure showing a planned course (thin line) and a course (thick line) of a hull affected by a side slip angle. It is a block diagram of a reach calculation part. (A) is a figure showing the route regarding reach, (b) is the figure which converted (a) into X'O'Y 'coordinate. It is a graph showing a simulation result. It is a graph showing a simulation result. It is a graph showing a simulation result. It is a graph showing a simulation result. It is a graph showing a simulation result. It is a graph showing a simulation result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ship automatic steering device 12 Trajectory plan part 14 Trajectory route error calculation part 16 Feedback control part 18 Estimator 20 Feedback gain device 30 Reference direction generation part 32 Side slip correction part 34 Reference speed generation part 36 Reference position generation part 40 Coordinate conversion part 42 Tidal Current Correction Unit 46 Feed Forward Steering Angle Generation Unit 48 Feed Forward Steering Angle Correction Unit 50 Reach Calculation Unit 52 Reference Direction Generation Unit 62 Preceding Coordinate Conversion Unit 64 Coordinate Conversion Unit 66 Tidal Current Correction Unit 72 Hull Speed Generation Unit (Hull Route Generation Unit )
74 Adder (Hull Route Generator)
76 Hull position generator (Hull route generator)
78 Reach output unit 80 Ship speed offset correction unit

Claims (10)

In an automatic steering apparatus for a ship provided with a trajectory planning unit that receives a ship speed detected by a sensor, generates a reference signal based on the planned route, and outputs a feed-forward steering angle for placing on the trajectory of the planned route when turning,
The trajectory planning unit
A reference azimuth generating unit for generating a reference azimuth ψ _R for making a turn in accordance with the planned route,
A skid correction unit for obtaining a reference skew angle β _R corresponding to a turning angular velocity generated by turning the rudder from a reference angular velocity r _R which is a time derivative of the reference orientation ψ _R ;
Based on the reference azimuth and the reference skew angle β _R , the feedforward rudder angle generating unit that generates a corrected feedforward rudder angle;
A marine vessel automatic steering apparatus comprising: The trajectory planning unit further includes:
Using reference direction ψ _R and ship speed U,

A reference speed generation unit for obtaining a reference speed vector (u _R , v _R ),
A reference position generator for outputting a reference position by integrating the reference velocity vector;
The marine vessel automatic steering apparatus according to claim 1, comprising: A trajectory planning unit that inputs the ship speed detected by the sensor, generates a reference signal based on the planned route, and outputs a feed-forward steering angle for placing on the trajectory of the planned route when turning, and a reference from the trajectory planning unit An orbital channel error calculation unit that calculates a trajectory error from the signal and the detection signal detected by the sensor, and a feedback control unit that outputs an estimated tidal current component and a feedback steering angle from the trajectory error,
In the boat automatic steering apparatus that performs steering by the feedback steering angle and the feedforward steering angle,
The trajectory planning unit
A reference azimuth generating unit for generating a reference azimuth ψ _R for making a turn in accordance with the planned route,
A coordinate conversion unit that obtains a lateral component of the hull of the tidal current by performing coordinate conversion based on the reference direction output by the reference direction generation unit for the estimated current component,
A tidal current correcting section for obtaining a corrected tilt angle β _d that opposes the tidal current from the lateral component coordinate-converted by the coordinate converting section;
The feedforward steering angle generator for generating a corrected feedforward steering angle based on the reference azimuth and the corrected skew angle β _d ;
A marine vessel automatic steering apparatus comprising: The trajectory planning unit further includes a side slip correction unit that obtains a reference skew angle β _R corresponding to a turning angular velocity generated by turning the rudder from a reference angular velocity r _R that is a time derivative of the reference orientation ψ _R ,
The coordinate conversion unit uses the reference course θ _R obtained by adding the reference direction ψ _R and the reference oblique angle β _R , from the estimated tidal component d _x ^, d _y ^,

4. The marine vessel automatic steering apparatus according to claim 3, wherein a lateral component v _d ^ of the hull of the tidal current is obtained according to The feedback control unit includes an estimator that estimates a tidal component, and a feedback gain unit that calculates a feedback steering angle by applying a feedback gain from a trajectory error,
The trajectory planning unit calculates a correction amount obtained by applying the feedback gain of the feedback control unit to the corrected skew angle β _d facing the tidal current, and corrects the feedforward steering angle based on the correction amount. The marine vessel automatic steering apparatus according to claim 3 or 4, further comprising a section. A trajectory planning unit that generates a reference direction based on the planned route and outputs a feed-forward rudder angle for turning on the trajectory of the planned route during turning to perform open-loop control, and performs steering by the feed-forward rudder angle In the ship automatic steering device
Prior to the start of turning steering, a reach calculating unit that calculates a distance (referred to as a reach) between the turning start position and the steering start position is provided.
A reference azimuth generator for obtaining a reference azimuth ψ _R from a turning radius obtained from the planned route and a predetermined turning angle;
A hull route generating unit for obtaining an expected hull route from the reference direction ψ _R ;
Find the distance in the azimuth direction (referred to as advance) from the steering start position to the position farthest in the azimuth direction at the start of the turn on the expected hull route determined by the hull route generation unit, and subtract the turning radius from the advance With the reach output part which asks for reach,
A marine vessel automatic steering apparatus comprising: The reach calculation unit further includes:
A coordinate conversion unit that obtains a horizontal component of the hull of the tidal current by performing coordinate conversion on the estimated tidal current component based on the reference direction output by the reference direction generation unit;
A tidal current correcting section for obtaining a corrected tilt angle β _d that opposes the tidal current from the lateral component coordinate-converted by the coordinate converting section;
The ship hull route generation unit according to claim 6, wherein the hull route generation unit obtains the predicted hull route using the corrected skew angle β _d .   The coordinate conversion unit performs coordinate conversion on the tidal component based on the reference direction output from the reference direction generation unit to obtain a bow direction component of the tidal hull, and the reference direction generation unit is based on the bow direction component. The ship automatic steering apparatus according to any one of claims 3 to 7, wherein a reference direction for making a turn in accordance with a planned route is obtained in accordance with a change in ground speed.   The marine vessel automatic steering apparatus according to claim 8, wherein the reference azimuth generation unit outputs a reference azimuth using a turn specified angular velocity corrected according to a change in ground speed.   A ship speed offset correction unit that corrects a ship speed by obtaining a ship speed offset after a turn from a reference direction and an estimated tidal current vector before turning and a reference direction and an estimated tidal current vector after turning is provided. The automatic steering device for a ship according to any one of 1 to 9.

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