JP2013056658A - Automatic steering device for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic steering device for ship which enables a ship to follow the planned ship course by taking into consideration a tidal current component during the turn while avoiding a saturated condition of a steering gear.SOLUTION: The automatic steering device for ship includes: a reference azimuth generation portion 30 for generating the reference azimuth ψfor making a turn following the planned ship course; a coordinate transformation section 40 for performing the coordinate transformation of the estimated tidal current component based on the reference azimuth output from the reference azimuth generation portion 30; a tidal current correction section 42 for obtaining the oblique sailing angle βcounteracting the tidal current using the tidal current speed component subjected to the coordinate transformation by the coordinate transformation section 40; a feedforward rudder angle generation section 46 which obtains the reference rudder angle δfor achieving the reference azimuth ψand the tidal current rudder angle δfor generating the oblique sailing angle βd, and generates the feedforward rudder angle δusing these obtained rudder angles; and a rudder angle setting section 28 for obtaining the reference rudder angle set value δby using the estimated tidal current component. The reference azimuth generation portion 30 generates the reference azimuth ψin such a way that the reference rudder angle δdoes not exceed the reference rudder angle set value δobtained by the rudder angle setting section 28.

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 tracked to a planned route by considering a tidal current component when turning.

  The automatic steering system for ships has a heading control system (HCS: Heading Control System) that controls the rudder angle and follows the heading to the set direction, and a track control system (TCS: Track Control System) 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. 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. Therefore, 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 steering machine of the hull 24. The planned route is determined from a straight line and a curved arc.

  At the time of turning, the tidal component applied to the hull changes depending on the heading direction. Therefore, if the tidal component is not taken into account, a channel error will occur transiently.

  Therefore, the inventor of the present application proposes a technique of reference azimuth and feedforward control that can cause the bow azimuth to follow the reference azimuth without delay in the azimuth control system proposed in Patent Literature 1, Non-Patent Literature 1 and Patent Literature 2. Patent Document 3 proposes an automatic steering apparatus for a ship that can be placed on a trajectory of a planned turn at the time of turning by taking into account the tidal current component that acts on the hull based on the above.

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 JP 2009-248897 A

In Patent Document 3, the feedforward steering angle δ _FF output from the trajectory planning unit 12 at the time of turning is the addition of the reference steering angle δ _R and the tidal steering angle δ _D, and δ _R changes the bow direction ψ to the amount of change Δψ ₀ equivalent to veering, [delta] _D has become as to correct the route error due tide.

Maximum value of the feedforward steering angle [delta] _FF, if the reference steering angle [delta] _R without power flow corrected, but matches the steering angle set value [delta] _0, if the tide correction is coincident to the steering angle set value [delta] ₀ do not do. This is because when the tidal component (tidal vector) increases the ground speed, the maximum value of δ _R and δ _D increases because the turning angular velocity increases. As a result, there is a problem that the maximum value of the feedforward steering angle δ _FF becomes larger than the steering angle setting value δ _0, the saturation state exceeds the allowable value of the input amplitude of the steering machine, and steering failure occurs.

  The present invention has been made in view of such a problem, and provides an automatic steering apparatus for a ship that can be traced to a planned route by considering a tidal component during turning while avoiding a saturated state of a steering machine. Objective.

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. A trajectory planning unit that outputs the feedforward steering angle, a trajectory route error calculating unit that calculates a trajectory error from a reference signal from the trajectory planning unit and a detection signal detected by the sensor, and an estimated tidal component from the trajectory error And a feedback control unit that outputs a feedback rudder angle,
In the marine vessel automatic steering apparatus that causes the steering machine to steer 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 performs coordinate conversion based on the reference direction output by the reference direction generation unit, the estimated tidal current component;
A tidal current correction unit for obtaining a skew angle β _d that opposes a tidal current from a tidal component that has been coordinate-transformed by the coordinate transformation unit;
A reference steering angle δ _R for setting the reference azimuth ψ _R and a tidal current steering angle δ _D for generating the skew angle β _d are obtained, and a feedforward steering angle δ _FF is generated from these steering angles. A feed forward rudder angle generator,
A rudder angle setting unit for _obtaining a reference rudder angle setting value _δ0R using the estimated tidal current component;
The reference azimuth generating unit generates the reference azimuth ψ _R so that the reference rudder angle δ _R does not exceed the reference rudder angle setting value δ _0R obtained by the rudder angle setting unit. .

According to a second aspect of the present invention, in the first aspect, the rudder angle setting unit corrects a predetermined rudder angle setting value δ ₀ by using the estimated power flow component to thereby set the reference rudder angle setting. The value δ _0R is obtained.

The invention according to claim 3 is the one according to claim 2, wherein the reference rudder angle setting value δ _0R is determined from a predetermined rudder angle setting value δ ₀ , an estimated tidal velocity U _d, and a ship speed U.

として求めることを特徴とする。

It is characterized by obtaining as.

According to a fourth aspect of the present invention, in the second aspect, the reference rudder angle setting value δ _0R includes a predetermined rudder angle setting value δ ₀ , an estimated tidal velocity U _d, and a reference rudder angle δ _R. From the reference direction ψ _R , the tidal direction ψ _d and the ship speed U when it is generated,

として求めることを特徴とする。

It is characterized by obtaining as.

The invention according to claim 5 is the one according to any one of claims 1 to 4,
The tidal current correction unit sets a tilt angle β _d against the tidal current,

から求めることを特徴とする。

It is characterized by obtaining from.

The invention described in claim 6 is the one described in any one of claims 1 to 5,
The coordinate conversion unit performs coordinate conversion on the basis of the reference azimuth output from the reference azimuth generation unit for the estimated tidal current component to obtain a tidal current component in the reference azimuth direction, and the reference azimuth generation unit includes the reference azimuth direction. The reference azimuth for turning according to the planned route is obtained using the specified turning angular velocity corrected in accordance with the change in the ground speed due to the tidal component.

According to the present invention, the reference rudder angle set value δ _0R is set using the estimated tidal component, and the reference azimuth ψ _R is generated so that the reference rudder angle δ _R does not exceed the reference rudder angle set value δ _0R. By doing so, it is possible to regulate the maximum value of the feedforward steering angle δ _FF , avoiding the inability to control due to the saturation of the steering machine, and realizing a safe turning maneuvering.

Further, since the reference rudder angle set value _Δ0R can be obtained by a simple calculation, the mounting process can be simplified.

(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. (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). It is a graph which shows the time change (however, in the case of a stable ship) of a reference direction and a reference rudder angle. It is a figure showing the state at the time of turning. 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.

  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. 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. The track planning unit 12, the track route error calculating unit 14, the feedback control unit 16, the adder 17, and each parameter are set. An identifier (not shown) for identification is provided. From the guidance system 22, the ship speed U from the planned route and the speed log of the sensors 26 (more precisely, the hull surge speed u (u≈U as will be described later)) is input to the trajectory planner 12. From the reference direction ψ _R , reference position x _R , y _R reference signal and feed-forward steering angle δ _FF during turning.

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) from the satellite positioning system (GNSS) such as GPS. The unit 14 compares the reference azimuth ψ _R , the reference positions x _R , y _R with the detection signal, and azimuth error ψ _e , position errors x _e , y _e (the azimuth error and position error are collectively referred to as trajectory error). ) Etc.

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 ψ ^ _e , the position error y ^ _e , and the tidal vector d ^ _x , d ^ _y of the azimuth error system are estimated from the azimuth error ψ _e and the position errors x _e , y _e . Feedback gain unit 20, for each error, multiplied by the feedback gain G _FB, and outputs a feedback steering angle [delta] _FB.

The adder 17 adds the feed forward steering angle δ _FF and the feedback steering angle δ _FB , and outputs the command steering angle δ _C to the steering machine. The steering machine moves the steering angle proportional to the command steering angle, The hull 24 including the steering machine is moved.

  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 function of the automatic steering system for a ship 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, the trajectory planning unit 12, when a planned route of a curved route is input from the guidance system 22, obtains the turning condition and generates a reference direction ψ _R that matches the turning condition. A reference speed generator 34 for generating a reference speed of the hull, a reference position generator 36 for generating a reference position by integrating the reference speed of the hull, and a tidal component of the reference coordinate system by converting the estimated tidal current to coordinates. A coordinate transformation unit 40 that generates, a tidal current correction unit 42 that generates a slant angle β _d to counter the tidal current, a ground speed correction unit 44 that corrects the ground speed, and a hull direction as a reference direction ψ _R + slope A feed-forward steering angle generator 46 that outputs a feed-forward steering angle δ _FF to follow the navigation angle β _d without delay, and a feed-forward steering angle correction unit 48 that corrects the feed-forward steering angle are provided. In addition, a steering angle setting unit 28 that corrects the steering angle setting value δ ₀ and avoids the saturation state of the steering machine in a turning condition is provided.

The tidal current component estimated in the ground system is converted by the coordinate conversion unit 40 based on the reference direction ψ _R , and the tidal current correction unit 42 obtains a corrected skew angle β _d to counter the tidal current from the coordinate converted tidal current component. by executing the feed-forward control by converting the feed-forward steering angle feedforward steering angle generating section 46 including the modified oblique Wataru angle beta _d, modifications and tide of the reference orientation direction perpendicular velocity component oblique Kou angle beta _d And the hull route follows the reference direction ψ _{R and} can prevent a channel error due to tidal currents.

Moreover, since the reference azimuth direction velocity component of the tidal hull changes in conjunction with the azimuth, the ground speed changes during the turn. In order to realize a turn with a constant radius, when the ground speed changes, the ground speed correction unit 44 corrects the designated turning angular speed r ₀ ^* for obtaining the reference orientation. As a result, the hull route follows a route with a constant 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 coordinate system (XOY): A latitude-longitude coordinate system fixed on the earth, which corresponds to position output (x, y) from GNSS.
-Hull coordinate system (X _B GY _B ): This is a motion coordinate system that is fixed to the hull. The hull center of gravity is the origin, the heading is the X _B axis, and the hull motion is determined.
And the reference coordinate system _{(X R O R Y R)} : a moving coordinate system is generated is determined from the specified planned route by 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 Model The hull model P of the hull 24 to be controlled is

It can be expressed as. Here, s means a Laplace operator, K _s , T _s , and T _s3 are hull parameters, K _s is a turning force gain, and T _s and T _s3 are time constants.

FIG. 4 shows an overview 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. The transfer characteristic from the reference direction ψ _R to the head direction ψ by feedforward control is

になる。

become.

Here, if the parameter uncertainty of P ⁻¹ is negligibly small, the bow direction ψ can follow the reference direction ψ _R without delay according to the equation (2).

Therefore, to have a transfer characteristic of P ^-1 with respect to the reference azimuth [psi _R, it can be determined the steering angle, to follow the reference azimuth [psi _R. P ^-1 is ^calculated from equation (1)

で表される。または、Ｔ_s3≪Ｔ_sであるので、Ｔ_s3を無視した場合には、

It is represented by Or, since T _s3 << T _s , if T _s3 is ignored,

で表される。

It is represented by

2. Turning Trajectory 2.1 Rudder Speed Setting Value and Rudder Angle Setting Value The hull direction ψ can be made to follow the reference direction ψ _R by equation (2).
The signals input to the trajectory planning unit 12 are the planned route and the ship speed U, and the signals output from the trajectory planning unit 12 are the reference direction ψ _R , the reference positions x _R , y _R , and the feedforward steering angle δ _FF. It becomes.

When the planned route of the curved route is input from the guidance system 22, the reference direction generation unit 30 determines the turning radius R, the amount of change (turning angle) Δψ ₀ , and the designated turning angular velocity r ₀ that are turning conditions. Further, as other turning conditions, hull parameters T _s , K _s , T _S3, etc. (these hull parameters are predetermined values or identified every time they turn by an identifier), the initial angle of hull motion There are acceleration C _1a , initial angular velocity C _2a , steering angle setting value δ ₀ , steering angle maximum value δ _max , steering speed maximum value δ ^· _max , steering speed setting value δ ^· ₀ and the like.

The rudder speed set value δ ^· ₀ is set as appropriate, and can be set to about δ ^· ₀ = 2.0 [deg / sec], for example. The maximum value δ ^· _max is determined from the specification of the steering machine, and can be set to about 7/3 [deg / sec], for example, and the steering speed ratio is δ ^· ₀ / δ ^· _max = 2 ÷ (7/3) ≈ 0.857. However, if δ ^· ₀ is set separately for stable ships and unstable ships, follow that.

The steering angle setting value δ ₀ is set as appropriate. The maximum rudder angle value δ _max is determined by the specification of the steering machine, and can be, for example, about 35 [deg]. For a stable ship, using the rudder speed ratio, the rudder angle set value δ ₀ is

程度に設定することができ、不安定船では、δ_maxまで１０度の余裕をもたせるので、２５ [ｄｅｇ]程度に設定することができる。

In an unstable ship, it has a margin of 10 degrees up to δ _max , so it can be set to about 25 [deg].

The rudder angle set value δ ₀ is output to the rudder angle setting unit 28, where replacement is performed to prevent the feedforward rudder angle δ _FF from exceeding this rudder angle set value δ ₀ and the reference rudder is set. An angle set value δ _0R is obtained. Then, the reference rudder angle setting value δ _0R is returned to the reference bearing generation unit 30. Specific calculation of the reference rudder angle set value _Δ0R will be described later.

2.2 Reference Orientation When the reference orientation generating unit 30 determines the change amount (turning angle) Δψ ₀ and the designated turning angular velocity r ₀ of the turning condition, the reference orientation generating unit 30 calculates a reference orientation ψ _R that satisfies these. In this calculation, Patent Document 1
Alternatively, the trajectory calculation unit proposed in Patent Document 2 can be used, and the trajectory calculation unit divides the reference direction into the acceleration mode, the constant speed mode, and the deceleration mode sequentially for the desired amount of change of the ship, In this case, the maximum rudder speed is determined in accordance with the amount of change of needle, and the reference rudder angle corresponding to the calculated reference direction does not exceed the reference rudder angle setting value δ _0R. Is calculated and the reference orientation ψ _R is output (FIG. 5). Specifically, it can be performed as follows.

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

ここでｔ：[０≦ｔ≦Ｔ_a]、Ｔ_a：加速時間、η_a：加速定数、Ｃ_1a，Ｃ_2a：初期値で変針
開始時は両者とも０である。

Here, t: [0 ≦ t ≦ T _a ], T _a : acceleration time, η _a : acceleration constant, C _1a , C _2a : initial values, both of which are zero at the start of the course change.

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

ここでｔ：[０≦ｔ≦Ｔ_v]、Ｔ_v：等速時間である。

Here, t: [0 ≦ t ≦ T _v ], T _v : constant speed time.

The second-order differential, first-order differential, and reference orientation ψ _Rd of the reference orientation ψ _R in the deceleration mode can be expressed as follows.

ここでｔ：[０≦ｔ≦Ｔ_d]、Ｔ_d：減速時間である。Ｃ_1d，Ｃ_2d：初期値で各モード間の連続性、ψ^・・ _Ra（Ｔ_a）＝０、ψ^・ _Rd（Ｔ_d）＝０等を考慮すると、

Here, t: [0 ≦ t ≦ T _d ], T _d : deceleration time. C _1d , C _2d : Considering the continuity between the modes at the initial value, ψ ^· _Ra (T _a ) = 0, ψ ^· _Rd (T _d ) = 0, etc.

の関係が成り立つ。

The relationship holds.

The reference rudder angle δ _R is calculated from the reference direction ψ _R using the formula (4) (or the formula (3)).

になる。

become.

2.3 Maximum Reference Rudder Angle The reference rudder angle δ _R has an extreme value in the acceleration and deceleration modes because the second derivative of the reference direction is a quadratic function. The reference rudder angle δ _R and rudder speed δ ^· _R can be obtained by substituting the equations (5) and (6) of the reference azimuth for each mode of acceleration and deceleration into the equation (7)

となる。ここで、ａ₃、ａ₂、ａ₁、ａ₀はそれぞれ加速モード（添字（・）_a）と減速モード（添字（・）_d）に対して、

It becomes. Here, a ₃ , a ₂ , a ₁ , a ₀ are respectively for the acceleration mode (subscript (•) _a ) and the deceleration mode (subscript (•) _d ).

になる。

become.

  Since the maximum value of the maximum rudder angle is an extreme value that makes the rudder speed zero, the time from Equation (9) is

Given in. Here, with respect to the ± polarity of the molecule, + corresponds to a stable ship, and − corresponds to an unstable ship. The maximum absolute value of the rudder angle is the maximum rudder angle that occurs in the acceleration mode for stable ships, and the minimum rudder angle that occurs in the deceleration mode for unstable ships. It is obtained by substituting time t _{δ′R = 0} into the equation (8).

2.3.1 In the case of a stable ship When the initial values C _1a and C _2a are set to 0, and T _s > T _{a and} the second order of the Taylor expansion is used, the time to take the extreme value is obtained from equation (10) ,

になるから、極値の時間は、

So the extreme time is

become. The first term in parentheses in the above equation corresponds to the extreme time of the second derivative of the reference orientation, and the second term corresponds to the extreme time of the first derivative of the reference orientation. Therefore, the maximum value of the rudder angle is obtained by substituting equation (11) into equation (8)

になる。

become.

2.3.2 In the case of an unstable ship Except for generating the minimum rudder angle in the deceleration mode, the extreme time is the same as in the case of a stable ship.

となり、舵角の最小値は、

And the minimum rudder angle is

となる。

It becomes.

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

とする。

And

If the specified turning angular velocity r ₀ = U / R at constant speed is determined, and the acceleration time T _a , acceleration constants η _a and R _vd are determined, each coefficient is determined, and the reference direction ψ _R in each mode is determined. Can be sought.

Thereafter, _assuming that 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 η _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Δψ₀は、

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

となり、書き直すと、

And then rewrite

になる。

become.

The reference azimuth generating unit 30 determines the maximum steering speed from the amount of needle change, based on the calculated reference azimuth so that the steering speed of the corresponding reference steering angle δ _R does not exceed the determined maximum steering speed, and T _a and η _a are determined so that the reference rudder angle δ _R does not exceed the reference rudder angle set value δ _0R .

More specifically, when it is assumed that the turning angular velocity r _R is equal to the designated turning angular velocity r ₀ , the reference rudder angle δ _R satisfies a condition (steering angle condition) that is equal to or less than the reference rudder angle set value δ _0R. The turning angular velocity r _R is determined as the designated turning angular velocity r ₀ , and when the condition is not satisfied, the angular velocity that _minimizes the deviation between the reference steering angle δ _R and the reference steering angle setting value δ _0R is set as the turning angular velocity r _R. And set it as the new designated turning angular velocity. Then, the maximum steering speed δ _R ^· at the determined designated turning angular speed is set as the steering speed upper limit value.

When determining whether or not the reference rudder angle δ _R satisfies the condition of the reference rudder angle set value δ _0R or less (steering angle condition), it is determined whether or not the condition is satisfied while changing the equal reduction ratio R _vd . If the steering angle condition is not satisfied even when the equal reduction ratio R _vd is changed, the turning angular speed r _R is changed to find the turning angular speed r _R that satisfies the steering angle condition.

2.5 Reference Position Using the reference orientation ψ _R output from the reference orientation generator 30, the reference speed 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方向を表し、ｔは時間を表す。そして、これを参照位置発生部３６で積分することで、参照航路を、

Obtained from. Here, u _R and v _R are ground system reference velocities respectively representing x and y directions, and t is time. Then, by integrating this with the reference position generator 36, the reference route is

として求める。

Asking.

2.6 Reference Steering Angle The reference bearing generation unit 30 outputs the sequentially calculated reference bearing ψ _R to the feedforward steering angle generation unit 46, and the feedforward steering angle generation unit 46 formula (3) or (4) Thus, the reference rudder angle δ _R is calculated.

3. Speed of reference coordinate system 3.1 Conversion of tidal vector Figure 6 shows a state of turning with a constant radius. Where XOY: ground coordinate system, WP ₁ , WP ₂ : positions of the start and end of arc turning, R: turning radius, Δψ ₀ : turning angle (amount of needle change), ψ _R1 , ψ _R2 : straight lines before and after turning leg orientation, WOP: starting position of veering mode (end position near WP _2), u, v: hull surge speed of the hull coordinate system, sway velocity, d _x, d _y: in tidal velocity component of the ground coordinate system Yes, it contains the velocity component due to the wind force pushing the hull superstructure.

  The ground speed in the reference coordinate system is the sum of the water speed and the tidal velocity,

become. Here, u ^* and v ^* are velocity components in the reference coordinate system, u _β and v _β are water velocity components in the reference coordinate system, u _d and v _d are tidal velocity components in the reference coordinate system, and each component is , The reference azimuth direction (becomes tangential to the arc) and its right-hand orthogonal direction (becomes normal to the arc) are positive,

となる。ここで、β_dは潮流修正のための斜航角であり、

It becomes. Where β _d is the tilt angle for tidal correction,

It is. Here, K _v represents the hull cross flow gain _{(K v / K s <0} ), U (= √ (u 2 + v 2)) is to water speed, using the relationship u ² >> V ^2, U = U. U _d (= √ (d _x ² + d _y ² )) is a tidal velocity, and ψ _d (= tan ⁻¹ (d _y / d _x )) is a tidal direction.

The coordinate conversion unit 40 uses the estimated tidal current components d _x ^ and d _y ^ of the ground coordinate system obtained from the estimator 18 as the tidal velocity components d _x and d _y , and the reference direction φ generated by the reference direction generating unit 30. _{Using R} (
It is converted into tidal velocity components u _d and v _d in the reference coordinate system by the equation (17).

3.2 Correction concerning tidal current component The velocity component of the reference coordinate system expressed by the equation (15) is corrected as follows.

3.2.1 Regarding v ^{* From} Equations (15) and (16), _let β _d be a small angle,

And approximate. v is the sway speed in the hull coordinate system, which corresponds to the lateral flow speed generated during turning. Although the correction related to the lateral flow speed may be reflected in the feedforward steering angle, it will cause further increase in the feedforward steering angle, and will be omitted here. This is because it is possible to cope by correcting the lateral flow velocity by calculating the distance (referred to as “reach”) between the turning start position and the turning start position.
So the correction is

Is adjusted by adjusting the skew angle β _d and canceling v _d . Therefore, the tidal current correcting unit 42 obtains the skew angle β _d from the equation (21).

3.2.2 Regarding u ^{* The} specified turning angular velocity r ₀ ^{* including the} tidal component is

になる。ここで、ＳｅｔΔｕ：速度更新設定値（例えば１ｋｎｏｔ）、ｕ₀ ^*：前回の値とする。

become. Here, SetΔu is a speed update setting value (for example, 1 knot), and u ₀ ^{* is a} previous value.

When the change in the ground speed u ^* obtained by the expressions (15), (21), and (16) exceeds Δu, the ground speed correcting unit 44 follows the expression (22) and designates the specified turning angular speed r ₀ ^*. Is updated together with the ground speed u ^* to the reference bearing generator 30.

The reference orientation generating unit 30 recalculates the reference orientation ψ _R that satisfies the updated designated turning angular velocity r ₀ ^* . The amount of change at that time is the amount obtained by subtracting the direction already changed,

になる。ここでψ₀ ^*：変化する指定変針量、Δψ₀：計画航路の変針量、Δψ’_R：既に変針された方位量である。

become. Here, ψ ₀ ^{* is} the designated amount of change in the course of change, Δψ _{0 is the} amount of change in the planned route, and Δψ ′ _R is the amount of direction that has already been changed.

3.3 Feed-forward rudder angle The feed-forward rudder angle generating unit 46, in addition to the reference rudder angle (equation (7)), allows the planned current route to track the hull route. Request [delta] _D.

The tidal angle δ _D corresponding to the tidal angle β _d of the tidal current is expressed by the following equation (3) or (4):

により得られる。

Is obtained.

3.4 Feedforward Correction The tidal angle β _d of the tidal current is an estimated tidal current component d obtained from the estimator 18 in the feedback controller 16 of the closed loop system, as shown in the equations (21) and (17). _x ^{^,} so obtained from d _y ^{^,} by adding to the reference azimuth [psi _R, and outputs the track route error calculating unit 14, is configured a minor loop, the control system characteristic is changed.

Therefore, since β _d cannot be returned to the front, the feed forward steering angle correction unit 48 corrects it backward.

The deviation obtained by the orbital route error calculation unit 14 when the skew angle β _d is returned forward is:

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

become. Here, ψ _e = ψ _R −ψ. The feedback rudder angle including the tilt angle β _d is

になる。尚、フィードバックゲインＧ_FBは、Ｇ_FB＝Ｋ_P＋Ｋ_Dｓである。

become. The feedback gain G _FB is G _FB = K _P + K _D s.

  Therefore, the feedback rudder angle

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、を得ることができる。

By carrying out correction by, it is possible to obtain the same response characteristic, and when returned to the front of the [psi _R.

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.

4). The maximum value of feedforward rudder angle (17)

となり、ｖ_dの導関数は、上式から、

And the derivative of v _d is

となる。ｖ_dの２次微分は、コリオリ項（第２項）を含む。斜航角β_d修正のための潮流舵角δ_Dは、（２４）式から

It becomes. The second derivative of v _d includes a Coriolis term (second term). The tidal angle δ _D for correcting the tilt angle β _d is given by equation (24)

になる。ここで、（２１）式、（２８）式、（２９）式による

become. Here, according to equations (21), (28), and (29)

の関係を用いている。

The relationship is used.

The feedforward steering angle δ _FF is the sum of the reference steering angle δ _R and the tidal steering angle δ _D.

become. Examining the possible size of δ _FF , it changes depending on the polarity of sin and cos of the deviation between the tidal direction and the reference direction, and the maximum absolute value occurs when δ _D has the same polarity as δ _R.

The size of R _ψ is examined. In the case of a stable ship, substituting (5) and (11) into the denominator and numerator of (31) respectively,

を得る。ここで、Ｔ'_a＝Ｔ_a／Ｔ_s、ｒ^* ₀＝η_a・Ｔ_a／６の関係を用いている。また、Ｔ'_aの２乗項以上を省く。上式２つの比率をとると、

Get. Here, the relationship of T ′ _a = T _a / T _s and r ^* ₀ = η _a · T _a / 6 is used. Further, the square term of T ′ _a or more is omitted. Taking the above two ratios,

に近似することができる。以下表に２つの例（一方が通常例、他方が極端な例）を例示する。

Can be approximated. The table below illustrates two examples (one is a normal example and the other is an extreme example).

  Substituting the above two examples into equation (33)

になり、数値例からはＲ_ψの範囲として、上記条件を満足することが示される。

The numerical example shows that the above condition is satisfied as the range of R _ψ .

Usually, R _ψ is about 0.1. In the coefficient of U _d / u on the right side of equation (32),

から、ｃｏｓの項は、ｓｉｎの項よりも支配的になると見なせるので、

From this, the cos term can be considered to be more dominant than the sin term.

に近似することができる。上式より、δ_FFは、ｃｏｓ（ψ_d−ψ_R）の値により増減し、その最大値は、

Can be approximated. From the above equation, δ _FF increases or decreases depending on the value of cos (ψ _d −ψ _R ), and its maximum value is

become. If δ _FF at the time of tidal correction exceeds δ ₀ from the above equation, input saturation of the steering machine is generated. Therefore, in order to prevent the problem, the rudder angle setting unit 28 sets the reference rudder angle setting value δ _0R with respect to the default rudder angle setting value δ ₀ as follows.

参照舵角設定値δ_0Rを参照方位発生部３０へ出力することによって、フィードフォワード舵角δ_FFの最大値は、

By outputting the reference steering angle setting value δ _0R to the reference bearing generation unit 30, the maximum value of the feedforward steering angle δ _FF is

になるため、入力飽和による不具合を回避することができる。舵角設定部２８は、軌道計画が呼ばれる度に、Ｕ（＝ｕ）及びＵ_dを求めて参照舵角設定値δ_0Rを更新する。
または、（３２）式において、同極性である２つの場合の、ψ_d−ψ_R＝０、４／πの場合を考える。

Therefore, it is possible to avoid problems due to input saturation. The rudder angle setting unit 28 obtains U (= u) and U _d each time the trajectory plan is called, and updates the reference rudder angle set value δ _0R .
Or, consider the case of ψ _d −ψ _R = 0, 4 / π in two cases having the same polarity in the equation (32).

Here, _x of | _x represents a value of deviation ψ _d −ψ _R. Since u ^* depends deviation, the value of [delta] _R also should be noted different. In addition, the actual maximum value of δ _R occurs when ψ _R changes slightly (see FIG. 5), and thus is not the same as the deviation value.
In the equation (38),

の条件が満足されるものとすると、フィードフォワード舵角の最大値は、

If the above condition is satisfied, the maximum value of the feedforward rudder angle is

になる。よって、舵角設定部２８で、既定の舵角設定値δ₀に対して参照舵角設定値δ_0Rを、

become. Therefore, the rudder angle setting unit 28 sets the reference rudder angle setting value δ _0R to the default rudder angle setting value δ ₀ ,

に設定し、それを参照方位発生部３０へ出力することによって、フィードフォワード舵角δ_FFの最大値は、

And the maximum value of the feedforward steering angle δ _FF is

になるため、入力飽和による不具合を回避することができる。舵角設定部２８は、軌道計画が呼ばれる度に、Ｕ（＝ｕ）及びＵ_dを求めて参照舵角設定値δ_0Rを更新する。

Therefore, it is possible to avoid problems due to input saturation. The rudder angle setting unit 28 obtains U (= u) and U _d each time the trajectory plan is called, and updates the reference rudder angle set value δ _0R .

5. Numerical calculation example It is verified by numerical calculation that the maximum value of the FF steering angle satisfies | δ _FF | _max ≦ δ _{0 based} on the reference steering angle setting value δ _0R of the reference steering angle δ _R.

  The turning condition is (Conversion: 1NM = 1852m, 1knot = 0.5144m / s)

その他、Ｕ＝２０ｋｎｏｔ，Ｕ_d＝５ｋｎｏｔ，Ｒ＝１ＮＭである。

In addition, U = 20 knot, U _d = 5 knot, and R = 1NM.

7 and 8 show Δψ ₀ = 90 deg, ψ _R1 = 40 deg, ψ _R2 = 130 deg, stable ship (δ ₀ = 30 [deg], ψ _d = ψ _R1 ), unstable ship (δ ₀ = 25 [ deg], ψ _d = ψ _R2 ), and the FF steering angle δ _FF is within the steering angle set value δ ₀ .

9 and 10 show a case where Δψ ₀ = 100 [deg] and SetΔu = 1 knot and ground speed correction is performed, (a) is the case where ψ _d = ψ _R1 , and (c) is the case where ψ _d = ψ _R2 . It is. The stable ship has the maximum FF steering angle δ _{FF in} the case of (a) and the unstable ship in the case of (c), but the FF steering angle δ _FF is within the steering angle setting value δ ₀ .

DESCRIPTION OF SYMBOLS 10 Automatic ship steering device 12 Trajectory plan part 14 Trajectory route error calculating part 16 Feedback control part 18 Estimator 20 Feedback gain device 28 Steering angle setting part 30 Reference direction generation part 34 Reference speed generation part 36 Reference position generation part 40 Coordinate conversion Unit 42 tidal current correction unit 46 feedforward rudder angle generation unit

Claims (6)

A trajectory planning unit that receives 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 marine vessel automatic steering apparatus that causes the steering machine to steer 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 performs coordinate conversion based on the reference direction output by the reference direction generation unit, the estimated tidal current component;
A tidal current correction unit for obtaining a skew angle β _d that opposes a tidal current from a tidal component that has been coordinate-transformed by the coordinate transformation unit;
A reference steering angle δ _R for setting the reference azimuth ψ _R and a tidal current steering angle δ _D for generating the skew angle β _d are obtained, and a feedforward steering angle δ _FF is generated from these steering angles. A feed forward rudder angle generator,
A rudder angle setting unit for _obtaining a reference rudder angle setting value _δ0R using the estimated tidal current component;
The reference azimuth generating unit generates the reference azimuth ψ _R so that the reference rudder angle δ _R does not exceed the reference rudder angle setting value δ _0R obtained by the rudder angle setting unit. Automatic steering device for ships. 2. The ship according to claim 1, wherein the rudder angle setting unit obtains the reference rudder angle setting value δ _0R by correcting the predetermined rudder angle setting value δ ₀ using the estimated power flow component. Automatic steering device. The reference rudder angle set value δ _0R is obtained from the default rudder angle set value δ ₀ , the estimated tidal velocity U _d, and the ship speed U.

The marine vessel automatic steering device according to claim 2, wherein the marine vessel is obtained as follows. The reference rudder angle set value δ _0R includes a predetermined rudder angle set value δ ₀ , an estimated tidal velocity U _d , a reference direction ψ _R when the reference rudder angle δ _R is generated, a tidal direction ψ _d , From ship speed U,

The marine vessel automatic steering device according to claim 2, wherein the marine vessel is obtained as follows. The tidal current correction unit sets a tilt angle β _d against the tidal current,

5. The marine vessel automatic steering device according to claim 1, wherein the marine vessel automatic steering device is obtained from:   The coordinate conversion unit performs coordinate conversion based on the reference azimuth output from the reference azimuth generation unit for the estimated tidal current component to obtain a tide component in the reference azimuth direction, and the reference azimuth generation unit includes the reference azimuth direction. 6. The ship according to claim 1, wherein a reference heading for turning according to the planned route is obtained using a specified turning angular velocity corrected in accordance with a change in ground speed due to a tidal component of the ship. Automatic steering device.

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