JP2018034590A - Ship automatic steering system - Google Patents

Abstract

[Problem] Corresponding to a hull with a small turning force gain. [Solution] The system includes a feedback controller that outputs a commanded rudder angle based on a reference heading and a heading to the controlled object, and the feedback controller includes an estimator that outputs an estimated deviation and an estimated angular velocity as estimated values based on the deviation between the reference heading and the heading and the commanded rudder angle, and a state feedback controller that multiplies the estimated deviation by a proportional gain KP set to a predetermined first specification gain value, and multiplies the estimated angular velocity by a differential gain KD that depends on the value of the proportional gain KP, and outputs the commanded rudder angle. [Selected Figure] Figure 6

Description

  The present invention relates to a marine vessel automatic steering apparatus having an estimator.

  A ship automatic steering device is a device that controls the rudder of a ship to follow the heading detected by a gyro sensor in a fixed setting direction, and has a function of holding and changing a needle, and its holding control system Is controlled by a feedback controller including a state feedback controller that performs PD control and an estimator that performs state estimation and disturbance removal.

  The hull model that is controlled by the automatic steering system for ships has a parameter uncertainty of the nominal value due to changes in loading.Therefore, an estimator configured with a model base of the nominal value introduces an error in the estimated value due to the parameter uncertainty. Arise. Due to this error, the closed-loop stability due to the state feedback of the estimated value may deteriorate, and yawing that causes the hull to meander may be caused.

With respect to such an error in the estimated value, in the Patent Document 1, the present inventors actively consider the parameter uncertainty of the nominal value of the hull parameter, thereby reducing the estimation error due to the parameter uncertainty. A ship automatic steering device to be reduced and a design method thereof are proposed. Here, λ _e2 is a characteristic polynomial for estimating the state quantity of the hull model from which the wave model is omitted, and ζ _e and ω _e are the attenuation coefficient and natural frequency for estimating the state quantity, respectively, and the characteristics of the estimator Polynomial

とし、ω_ｅ＝ρω_ｆを操舵系周波数ω_ｆのρ倍（ρ＞１で推定係数と呼ぶ）に設定し、ζ_ｅを１／√２に設定するように推定器を設計している。これによって、パラメータ不確かさによる推定角速度の推定誤差が低減される。

The estimator is designed so that ω _e = ρω _f is set to ρ times the steering system frequency ω _f (where ρ> 1 is referred to as an estimation coefficient), and ζ _e is set to 1 / √2. Thereby, the estimation error of the estimated angular velocity due to the parameter uncertainty is reduced.

  Furthermore, in this patent document 1, the estimation error is equivalent to the estimation error when only the hull model is used for the control target composed of the hull model, the wave model, and the rudder angle offset model. It is proposed to modify the natural frequency of the estimator from the disturbance model characteristics. According to this, the control object of the estimator is equivalent only to the hull model, and the disturbance model can be ignored.

In addition, in the patent document 2, the present inventors pay attention to the estimation coefficient ρ = ω _e / ω _f as the representative root of the steering loop, and design the control gain from the relationship between the attenuation coefficient of the representative root and the parameter uncertainty. ing. Here, the estimation coefficient ρ that relates the natural frequency of the estimator and the natural frequency of the steering system is set by estimating the effect of parameter uncertainty based on the closed-loop system without an estimator and the closed-loop system with an estimator. doing.

In addition, in the patent document 3, the present inventors based on a closed-loop characteristic polynomial including an estimator including two disturbance models, a characteristic polynomial D obtained by adding a parameter uncertainty Δ of a hull parameter to this characteristic polynomial. _{From c} ^Δ , when the parameter uncertainty Δ is the first specification value (Δ _spec ), the minimum attenuation coefficient ζ among the attenuation coefficients obtained from the characteristic root of D _c ^Δ (s) is defined as ζ _e ^*. An automatic steering apparatus for a ship with increased closed-loop stability by obtaining an estimation coefficient ρ that satisfies the value of the second specification value (ζ _spec ) _e ^* and setting the natural frequency ω _e of the hull model of the estimator Has proposed.

Furthermore, in this patent document 3, the parameter uncertainty Δ is defined as the uncertainty (Δ _b ) of the ratio between the turning force gain of the hull parameter and the time constant. It has been proposed to improve reliability more than the conventional method in consideration of the estimated root.

  Some water jet propulsion ships that obtain propulsive force with nozzles that inject water flow are provided with a pair of nozzles on the left and right, and changing the needle by tilting these nozzles. When changing the course of a water jet propulsion ship, the nozzle has a dead band within a predetermined angle that is tilted to the left and right from the straight direction in which the ship goes straight. A technique is known that tilts outward by a certain nozzle offset so as to form a square shape, thereby equivalently canceling the dead zone.

Japanese Patent No. 4,603,832 Japanese Patent No. 4820621 Japanese Patent No. 5682009

  The above-described control system using an automatic steering system for ships is intended for various hulls from small ships to large ships. When this control system is applied to the above-described water jet propulsion ship, turning of the water jet propulsion ship is performed. Since the force gain is halved, it has been confirmed that a problem occurs in the process of obtaining the estimation coefficient. That is, according to the above-described marine vessel automatic steering apparatus, there is a problem that it is not limited to a water jet propulsion vessel and cannot cope with a hull having a small turning force gain.

  Embodiments of the present invention have been made to solve the above-described problems, and an object of the present invention is to provide a marine vessel automatic steering apparatus that can deal with a hull having a small turning force gain.

In order to solve the above-described problems, the marine vessel automatic steering apparatus according to the present embodiment is a marine vessel automatic steering apparatus that controls a control target including a hull and a steering machine so that the bow direction follows the reference direction. A feedback controller that outputs a command rudder angle based on the reference azimuth and the bow azimuth to the control target; the feedback controller based on a deviation between the reference azimuth and the bow azimuth and the command rudder angle An estimator that outputs an estimated deviation and an estimated angular velocity as estimated values; and the proportional gain K _P set to a predetermined first specification gain value is multiplied to the estimated deviation, and the proportional gain is multiplied to the estimated angular velocity. multiplied by the derivative gain K _D that depends on the value of K _P and a state feedback controller for outputting the command steering angle, configuration from the state feedback controller and the estimator Closed loop characteristic polynomial is the subscript _h azimuth control, subscript _e is the estimator, with modifications ^- represent respectively the nominal value, Laplace operator and s, D (s) the characteristic polynomial, the ζ damping coefficient, omega _{Is the} natural angular frequency, ζ _eh = ζ _h , ω _e = ρ ₂ ω _eh , ρ ₂ is the secondary estimation coefficient, K _r is the turning force gain, T _r is the hull time constant, T _r3 is the rudder sensitivity time constant, Δ Let _b , Δ _b ′, and d _{b be} scalar quantities of parameter uncertainty,

で表され、
前記状態フィードバック制御器は、前記微分ゲインＫ_Ｄの値が負値である場合、前記第１仕様ゲイン値より大きく設定された第２仕様ゲイン値を前記比例ゲインＫ_Ｐに設定し、前記推定器は、前記第２仕様ゲイン値に設定された比例ゲインＫ_Ｐと所定値に設定されたパラメータ不確かさΔ_ｂ’とに基づいて、前記閉ループの特性多項式により前記推定係数ρ_２を算出することを特徴とする。

Represented by
The state feedback controller, the case where the value of the derivative gain K _D of a negative value, setting the second specification gain value that is larger than said first specification gain value to the proportional gain K _P, the estimator Calculating the estimated coefficient ρ ₂ by the closed-loop characteristic polynomial based on the proportional gain K _P set to the second specification gain value and the parameter uncertainty Δ _b ′ set to a predetermined value. Features.

  According to the embodiment of the present invention, it is possible to deal with a hull having a small turning force gain.

It is a block diagram which shows the system containing the automatic steering device for ships which concerns on embodiment. It is a block diagram which shows the structure of a feedback controller. It is a block diagram which shows a secondary estimator. It is a figure which shows the asymptotic line of GH _h4 ( ^DELTA ) ^b (s). It is a diagram showing a root locus of ^GH _h4 Δb (s). It is a flowchart which shows the operation | movement of an estimation coefficient calculation process. It is a figure which shows the root locus of the representative root of (rho) ₂ = 4. It is a figure which shows a simulation result.

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

1. Automatic Ship Steering Device 1.1 Overall Configuration First, a system including an automatic ship steering device according to the present invention will be described. FIG. 1 is a block diagram showing a system including a marine vessel automatic steering apparatus according to an embodiment.

As shown in FIG. 1, the system in the present embodiment includes a marine vessel automatic steering apparatus 1 and a marine vessel 2 that is a control target thereof. Here, the ship 2 is a combination of a steering machine 21, a hull 22, and a gyrocompass 23 that detects the heading ψ ⁻ of the hull 22. Automatic marine steering system 1, heading [psi to set the azimuth [psi _R ^- comprises a feedback controller 10 for outputting a command steering angle [delta] _C to follow the to the steering device 21.

1.2 Feedback Controller The configuration of the feedback controller will be described. FIG. 2 is a block diagram showing the configuration of the feedback controller.

As shown in FIG. 2, the feedback controller 10 includes a state feedback controller 11 and an estimator 12. The estimator 12 outputs the estimated deviation ψ _e ^ and the estimated angular velocity r ^ based on the deviation ψ _e between the set direction ψ _R and the estimated direction ψ ^ and the command steering angle δ _C that is the output of the feedback controller 10. To do. The state feedback controller 11 multiplies the estimated deviation ψ _e ^ by a proportional gain K _p , multiplies the estimated angular velocity r ^ by a differential gain K _d , adds them, and outputs a command steering angle δ _C.

2 Control Object Here, the control object will be described. The object to be controlled is composed of a hull model and a disturbance model, but the disturbance model is omitted in this embodiment. The hull model uses the response model by the present inventor who improved Nomoto's response model.

に定める。ここでｓはラプラス演算子、Δ_ｃ（ｓ）、δ_ｃは命令舵角を示し、Ｋ_ｒは旋回力ゲイン、Ｔ_ｒは船体時定数、Ｔ_ｒ３は舵感度時定数を示す。この船体モデルは野本の船体モデルと比較して、Ｔ_ｒ３を有するという特徴をもつ。

Stipulated in Here, s is a Laplace operator, Δ _c (s), δ _c is a command rudder angle, K _r is a turning force gain, T _r is a hull time constant, and T _r3 is a rudder sensitivity time constant. This hull model is characterized by having _Tr3 as compared with Nomoto's hull model.

3 Design Hull motion characteristics are based on maneuverability index or hull motion parameters (hull parameters). The hull parameters are K _r , T _r , T _r3, and these values are obtained from a known identifier (not shown). Here, for _simplicity, and _{T r »T r3, T r3 ≒} 0. In the case of a small ship, particularly a water jet propulsion ship with a dead zone corrected, which will be described later, both K _r and T _r are both small, the differential gain of the azimuth control loop is small, and the value may be negative. Although the negative differential gain itself is not a problem, a problem arises when the estimation coefficient is calculated due to the negative differential gain.

The estimated gain k (k ₁ , k ₂ ) is used in the estimator 12 as shown in FIG. 3 and is a value that adjusts the influence of parameter uncertainty as disclosed in Patent Document 3, and is a characteristic polynomial described later. Calculate from When the differential gain is positive, all the coefficients of the characteristic polynomial are positive. On the other hand, when the differential gain is negative, some of the coefficients become negative, and the characteristics of the characteristic polynomial change. Therefore, it is necessary to cope with this change in properties.

3.1 Characteristics of differential gain If the differential gain is T _r3 = 0

になる。ここでＫ_Ｐは比例ゲイン、Ｋ_Ｄは微分ゲイン、ζ_ｈは減衰係数、ω_ｈは固有角周波数、添字_ｈは方位制御を示し、設計パラメータは、Ｋ_Ｐ≧１，ζ_ｈ＝１／√２になる。

become. Here _{K P} is a proportional gain, _{K D} is the differential gain, zeta _h is an attenuation coefficient, omega _h the natural angular frequency, subscript _h indicates the orientation control, the design _{parameters, K P ≧ 1, ζ h} = 1 / √ 2

From the above equation, the differential gain has a tendency to be proportional to ζ _h and √K _P with respect to the design parameter, and has a tendency to be proportional to √ (K _r / T _r ) and 1 / K _r with respect to the hull parameter. Therefore, the differential gain increases as the proportional gain increases. Next, the influence of the sign of the differential gain on the characteristic polynomial will be described.

3.2 Characteristics of characteristic polynomial The azimuth control loop becomes a seventh-order system when disturbance components are included, but becomes fourth-order when the disturbance components are excluded from the control target for simplification. As disclosed in Patent Document 3, the fourth-order azimuth control loop can grasp the basic characteristics of the closed-loop control system and includes a second-order hull motion model and its estimator. This closed-loop characteristic polynomial is

で与えられる。ここでｓはラプラス演算子、Ｄ（ｓ）は特性多項式、添字_ｅは推定器を意味し、

Given in. Where s is a Laplace operator, D (s) is a characteristic polynomial, subscript _e is an estimator,

ここで修飾^〜は船体２２の旋回の度に同定器により同定され更新されるノミナル値を示し、ζ_ｅｈ＝ζ_ｈ，ω_ｅ＝ρ_２ω_ｅｈであり、ρ_２は２次推定係数を示す。Δ_ｂ，Δ_ｂ’，ｄ_ｂはそれぞれパラメータ不確かさのスカラー量を示し、Ｔ_ｒ３＝０の場合はｆ_１＝Ｋ_Ｐ，ｆ_２＝Ｋ_Ｄ，Ｃ_Ｔ３＝１。なお、不確かさパラメータを船体パラメータの旋回力ゲインと時定数との比のパラメータ不確かさ（Δ_ｂ）とする点については、特許文献３を参照されたい。

Here modified ^~ represents the nominal value to be identified updated by the identifier every time the turning of the hull _22, ζ _{eh =} ζ _h, a _{ω e = ρ 2 ω eh,} ρ 2 represents the secondary estimation coefficient . _{Δ b, Δ b ', d} b each represent a scalar parameter _{uncertainty, f} 1 ₌ K _P For _{T r3 = 0, f 2 =} K D, C T3 = 1. Refer to Patent Document 3 for the point that the uncertainty parameter is the parameter uncertainty (Δ _b ) of the ratio between the hull parameter turning force gain and the time constant.

(2) The coefficients of b ₁ and b _{0 in} the equation are examined. If the estimated gains k ₁ and k ₂ satisfy the following conditions,

になる。これよりｂ_０＜０になり、ｂ_１の符号はｆ_２に依存する。すなわち

become. As a result, b ₀ <0, and the sign of b ₁ depends on f ₂ . Ie

になる。上式よりｆ_２≦‐ｆ_１（ｋ_１／ｋ_２）＜０になるから、ｂ_１の符号変化をｆ_２＝０の基準によって判定すればよい。さらにその基準は推定係数を含んだｋ_１，ｋ_２を用いないので、簡単に実現できる。よって、特性多項式は

become. Since f ₂ ≦ −f ₁ (k ₁ / k ₂ ) <0 from the above equation, the sign change of b ₁ may be determined based on the criterion of f ₂ = 0. Furthermore, since the reference does not use k ₁ and k _{2 including the} estimation coefficient, it can be easily realized. Therefore, the characteristic polynomial is

と置き換えることができる。上式でΔ_ｂが一定ならば、ｆ_２≦０の特性多項式はｆ_２＞０のそれに比べて係数が負になっているため、不安定根を生じやすい。

Can be replaced. If the above equation with delta _b is constant, the characteristic polynomial of f ₂ ≦ 0 Since coefficients than that of f _2> 0 is in the negative, prone to instability roots.

  As shown in FIG. 4, the asymptotic line of the root locus in the above equation changes, and the sign of the zero point also changes. Ie

になる。ここでｚはゼロ点を示す。よって、（２）式の根軌跡の一例は図５に示すように、不安定根の特性が異なることを確認できる。

become. Here, z indicates a zero point. Therefore, as shown in FIG. 5, an example of the root locus of equation (2) can confirm that the characteristics of unstable roots are different.

3.3 Parameter uncertainty specifications Parameter uncertainty specifications

とする。なお、ｆ_１＝μ^−１Ｃ_Ｔ３Ｋ_Ｄ，μ＞０，Ｃ_Ｔ３＞０の関係より、ｆ_２をＫ_Ｄに置き換えても良い。上式からパラメータ不確かさのマージンが半分となるが、船舶用自動操舵装置１は制御対象とする対象船が限定されるので、パラメータ変動は小さいとするためである。

And ^{_{Incidentally, f 1 = μ -1 C T3}} K D, μ> 0, the relationship of _{C T3>} 0, may be replaced by _{f 2} to _{K D.} This is because the margin of parameter uncertainty is halved from the above equation, but the ship automatic steering apparatus 1 is limited in the target ship to be controlled, so that the parameter fluctuation is small.

4. Estimation Coefficient Calculation Processing Next, the estimation coefficient calculation processing will be described. FIG. 6 is a flowchart showing the operation of the estimation coefficient calculation process. This estimation coefficient calculation process is a process executed every time the hull parameter is updated in the feedback controller in order to calculate an appropriate secondary estimation coefficient ρ ₂ in the estimator during navigation of the ship.

6, first, the state feedback controller 11 sets the first specification gain value set in advance in the proportional gain K _P (S101), calculates the differential gain K _D by (1) ( S102), determines whether the value of the derivative gain _{K D} of a positive (S103).

If the value of the derivative gain _{K D} of a positive (S103, YES), the estimator 12 sets the first specification value which is previously set in the parameter uncertainty _{Δ b '(S104), (} 2) expression of the characteristic A secondary estimation coefficient ρ ₂ is calculated by a polynomial (S105).

On the other hand, when the value of the derivative gain _{K D} of a negative (S103, NO), the second specification gain value set to a value greater than the first specification gain value set in the proportional gain _{K P} (S106), the proportional gain _K based on the _P (1) equation by calculating the derivative gain _{K D} (S107), it determines whether the value of the derivative gain _{K D} of a positive (S108).

If the value of the derivative gain _{K D} of a positive (S108, YES), the estimator 12 sets the first specification value to the parameter uncertainty delta _b '(S109), 2-order by the characteristic polynomial of the expression (2) It calculates an estimated coefficient ρ ₂ (S105).

On the other hand, when the value of the derivative gain _{K D} of a negative (S103, NO), sets the second design value set to a value smaller than the first design value to the parameter uncertainty _{Δ b '(S110), (} 2 ) the characteristic polynomial of equation to calculate the second order estimation coefficient [rho ₂ (S105).

The calculation of the secondary estimation coefficient ρ ₂ is performed so that the minimum attenuation coefficient ζ _e among the attenuation coefficients obtained from the characteristic root of the characteristic polynomial of equation (2) satisfies the specification ζ _Δ. The natural frequency ω _e of the hull model of the estimator 12 is set by ρ ₂ . For details of the calculation method of the estimation coefficient ρ, see Patent Document 3.

とする。ここでＴ_ｒ３は初期値。 5 Verification Perform numerical verification as a water jet propulsion ship with dead zone correction applied to the controlled object. The water-jet propulsion ship has a water jet propulsion machine including a pair of nozzles, and these nozzles have a dead zone within a predetermined angle that is inclined to the left and right from a straight traveling direction in which the ship moves straight. In order to correct this dead band, the operating position of the pair of nozzles is tilted outward by a nozzle offset, which is a correction angle corresponding to the dead band, so that the dead band is equivalently offset. It has come to be. Hull parameters of water jet propulsion ship

And Here, _Tr3 is an initial value.

The differential gain of the ship is shown in Table 1 below. The differential gain is negative when the dead zone is corrected from the table. However, _{Tr and} others remain unchanged before and after the dead zone correction.

FIG. 7 shows the results of calculating b ₁ , b ₀ , z and the representative roots ω and ζ with respect to the estimation coefficient ρ ₂ using the equation (7), K _P = 1.5, K _D = −4.9. Show. 7 that becomes _b 1> 0, z> 0 in [rho ₂ ≧ 4, zeta, against ω is uncertainty parameter _{d b,} inverse proportion, respectively, in proportion, approximately constant value [rho ₂ ≧ 4 . At this time, the specification d _b = 2 cannot be satisfied. FIG. 8 shows the root locus of the representative root of ρ ₂ = 4. FIG. 8B shows the result of FIG. 7D when 0 ≦ Δ _b ≦ 2K _r / T _r and Δ _b = 2K _r / T _r or d _b = 2 and ζ≈0.2. Almost matches. Therefore, the nominal value of the ship

に見積もると、本船の２次推定係数をρ_２≒４にすれば、ζ≒０．４になり仕様を満足することができる。

In this case, if the secondary estimation coefficient of the ship is set to ρ ₂ ≈4, ζ is about 0.4 and the specification can be satisfied.

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

DESCRIPTION OF SYMBOLS 1 Marine automatic steering apparatus 10 Feedback controller 11 State feedback controller 12 Estimator

Claims (3)

An automatic marine steering apparatus for controlling a control target including a hull and a steering machine so that a bow direction follows a reference direction,
A feedback controller that outputs a command steering angle based on the reference direction and the heading direction to the control target;
The feedback controller includes an estimator that outputs an estimated deviation and an estimated angular velocity as an estimated value based on a deviation between the reference azimuth and the bow azimuth and the command rudder angle, and a predetermined first for the estimated deviation. with multiplying the set proportional gain K _P to specifications gain value, and a state feedback controller for outputting the command steering angle is multiplied by a derivative gain K _D that depends on the value of the proportional gain K _P to the estimated angular velocity With
A closed-loop characteristic polynomial composed of the estimator and the state feedback controller has a subscript _h for azimuth control, a subscript _e for an estimator, and a modifier ^~ for a nominal value, s for a Laplace operator, and D (s ) Is the characteristic polynomial, ζ is the damping coefficient, ω is the natural angular frequency, ζ _eh = ζ _h , ω _e = ρ ₂ ω _eh , ρ ₂ is the secondary estimation coefficient, K _r is the turning force gain, and _Tr is the hull time _{constant, T r3} steering sensitivity time constant, delta _b, delta _b ', a _{d b} a scalar quantity parameter uncertainty respectively,

Represented by
The state feedback controller, the case where the value of the derivative gain K _D of a negative value, setting the second specification gain value that is larger than said first specification gain value to the proportional gain K _P,
Based on the proportional gain K _P set to the second specification gain value and the parameter uncertainty Δ _b ′ set to a predetermined value, the estimator uses the closed-loop characteristic polynomial to calculate the second-order estimation coefficient ρ _2. An automatic steering device for a ship, characterized in that The parameter uncertainty Δ _b ′ is set to a predetermined first specification value,
The estimator, when the value of the derivative gain K _D of a negative value, setting the second specification value set smaller than the first specified value to the parameter uncertainty delta _{b ',} the parameter uncertainty delta _2. The marine vessel automatic steering apparatus according to claim 1, wherein the second-order estimation coefficient ρ ₂ is calculated from the closed loop characteristic polynomial based on _b ′. When the value of the differential gain K _D calculated based on the proportional gain K _P set to the second specification gain value is a negative value, the estimator determines the second specification value as the parameter uncertainty Δ _b. 3. The marine vessel automatic steering apparatus according to claim 2, wherein the second-order estimation coefficient ρ ₂ is calculated using the closed-loop characteristic polynomial, based on the parameter uncertainty Δ _b ′.

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