JPS61119493A - Autopilot for vessel - Google Patents

Abstract

PURPOSE:To permit the automatic optimum steering by installing an external- disturbance characteristic calculation part which estimates the sea state such as wave external disturbance, and performs the external-disturbance correction calculation so that the hull is not given the large influence of the external disturbance and outputs an optimum steering angle signal. CONSTITUTION:The captioned apparatus is constituted of a hull dynamic characteristic calculation part 11A and an external-disturbance characteristic calculation part 20. In the calculation part 11A, the hull parameters and the dynamic characteristics of the hull are calculated and input into the calculation part 20. The wave external disturbance which acts onto the hull is estimation-calculated in a wave external- disturbance estimation calculation part 21, and the results are judged in an estimation- judging part 22. The results of calculation in the calculation part 21 are compared with the estimated model for the wave external-disturbance in a comparison-judging part 23. THe wave external-disturbance frequency which can be controlled for the hull is calculation-determined in a wave external-disturbance cycle determination part 25. The cycle is feedback-controlled into the calculation part 21 and outputted into a sea-condition judging part 26. In the judging part 26, the state of waves is judged and outputted into an external-disturbance correction-calculation part 27, where an optimum steering angle signal is outputted into a steering machine.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to marine autopilots, in particular, by estimating and calculating disturbance factors such as cargo and waves, and correcting these disturbance factors acting on the hull. This article relates to a marine autopilot that obtains optimal control gain and always steers the ship optimally. More specifically, we have developed a marine autopilot that directly controls yawing caused by external disturbances to improve course keeping and achieve high reliability, while at the same time achieving improved fuel efficiency by utilizing optimal regulator theory. It is about providing.

<Prior art> Conventional marine autopilots continuously estimate and calculate the self-orientation U based on a heading signal from a gyro compass, which is a heading signal generator, to align the ship on a set course around the yaw axis. Most of them adopted an automatic control method that allows them to board the vehicle using only attitude control. In other words, the difference between the ship's set course and heading only by attitude control around the yaw axis, the set turn rate when changing course (the turn rate was manually set and output using a changeover switch, etc.), and the actually measured turn rate. The navigator adjusts the control gain so that the difference between
was in control. Hereinafter, such a marine autopilot will be explained using a block diagram of a prior art marine autopilot shown in FIG.

In FIG. 10, 1 is the hull, 2 is a gyro compass that outputs a heading signal ψ, and 3 is a calculation unit that calculates and outputs a commanded rudder angle signal U0. The calculation unit 3 generates a course deviation signal Δψ from the heading signal ψ and the set course signal ψm0. a subtracter 4 that outputs a turn rate signal φ (.does not represent a first-order differential; hereinafter the same) a turn rate calculation unit 5 that outputs a turn rate signal φ
(In the figure, the vertical azimuth signal ψ is differentiated using a differentiator circuit, but a separate turn rate meter (not shown) may also be used). Rate signal φm. a subtracter 51 which calculates the difference between
An input filter section 6 consisting of a next-order lag filter or a second-order lag filter, and a course deviation f signal Δψ filtered by this input filter section 6. (f represents filtering, - represents a measured value. The same applies hereinafter) and the turn rate deviation f signal Δψ0 is subjected to PID calculation, and the command steering angle signal IJ is
It consists of a PID calculation circuit 7 which outputs o.

8 is a steering gear that drives the rudder 9 based on the commanded rudder angle signal [Jo.

The steering function of a marine autopilot with such a configuration will be explained below.

The subtracter 4 compares the heading signal ψ and the set course signal ψmO, and outputs a course deviation signal Δψ0 to the input filter unit 6. Further, the subtracter 51 compares the turn rate signal φ and the set turn rate signal small no, and outputs a turn rate deviation signal Δ(1)o to the input filter section 6. The course deviation signal Δψ0 and the turn rate deviation signal Δψ0 are filter setting values M manually set in advance in the input filter section 6.
"The heading deviation f signal Δψ is filtered based on
0, and is led to the PID calculation circuit 7 as a turn rate deviation I signal Δψ0. PIDmIDm calculation circuit heading deviation f signal Δφ0 and turn rate deviation! Signal Δn\ψ. PID calculation is performed based on the control parameter Mg (for example, PID control gain and time constant) which is manually set by the navigator from the outside, and is output to the steering gear 8 as a commanded rudder angle signal U0 to drive the rudder 9.

By the way, a marine autopilot with this configuration has
There were the following problems.

■: pro: In the arithmetic circuit 7, the control parameter M (J) that determines the optimum gain of the circuit is manually set by the navigator from the outside, so the control parameter MQ is set appropriately in response to changes in the motion characteristics of the hull 1. It is difficult to adjust to a suitable value.

(2): Even if the control parameter M(l) could be adjusted to an appropriate value, the burden placed on the navigator who sets it would be extremely heavy.

■: If the control parameter 9M9 cannot be adjusted to an appropriate value,
It is difficult to obtain the desired control characteristics, that is, high course keeping ability (course keeping) and high course changing ability (course change), and therefore high reliability of transportation cannot be expected, and it is difficult to achieve fuel efficiency of the pilot system. .

(2): Since the input filter group 6 is composed of a first-order lag (or second-order lag) filter, a sufficient filtering effect cannot be expected.

■When changing course, the difference between the set turn rate and the actual turn rate is detected, and a constant set turn rate signal is maintained according to this difference until the end of the course change, so the hull is affected by inertia and greatly overshoots. I end up doing it.

If there is a large overshoot while navigating through a narrow channel, there will be dangers such as collision with another vessel or being forced to the opposite shore.

<Prior Art> Therefore, in view of the problems of the prior art described above, the applicant filed Japanese Patent Application No. 59-91463. 11th
The figure is a block diagram of the marine autopilot described in this prior art. Portions in FIG. 11 that overlap with those in FIG. 10 are given the same numbers and their explanations will be omitted.

In FIG. 11, reference numeral 11 denotes a hull dynamic characteristic calculation unit that calculates the dynamic characteristics of the hull. The main components of this hull dynamic characteristic calculation section 11 are comprised of a hull characteristic estimation calculation section 12, a hull motion estimation calculation section 15, and an optimum calculation section 1G. The outline of each of these configurations is as follows.

Generally, when the rudder 9 is turned at a certain angle, the hull 1 gradually starts turning, and continues turning steadily when a certain turn rate is reached. The hull characteristic estimation calculation unit 12 receives a heading signal ψ
, a turn rate signal φ, and a rudder angle signal δ are inputted to perform calculations to estimate the characteristics of the hull 1, and output estimated hull parameters α and β. On the other hand, the heading signal φ includes disturbances that are harmful to steering (for example, changes in conditions such as cargo on the hull 1). This disturbance occurs in the hull 1 as a periodic movement. That is, since there is a difference between the course deviation signal Δψ0 and the U-turn rate signal ↓, if the difference is set at 9 each time, the resistance will increase and energy will be lost. However, in response to low-period disturbances, unless the rudder 9 is controlled to some extent, the hull 1 may move in an unexpected direction. Therefore, the hull motion estimation calculation unit 15 estimates and calculates the motion characteristics of the hull 1, removes high-frequency components harmful to steering between those caused by the actual movement of the hull 1 and those caused by disturbances, and removes high-frequency components harmful to steering between low-period disturbances and those caused by disturbances. The field is extracted and an estimated course direction signal ψ and an estimated turn rate signal ψ are output. Optimal calculation unit 1
6 is composed of an optimum gain calculation section G and an optimum steering amount calculation section 19. Here, the optimal gain calculation unit G is an estimation film Δ Δ .

The field parameters α and β are input and 6 is calculated as a gain matrix which is the optimum gain. Its configuration consists of a shield suitable gain adjustment law determination unit 17 that determines the optimal gain adjustment value suitable for the hull 1, and an optimal gain adjustment law determination unit 17 that inputs the adjustment value determined by this @appropriate gain adjustment law determination unit 17 and creates an optimal gain table. (Since it is almost impossible to find a steady solution online, the optimal control gain is determined in advance for each class of hull and stored in memory as a gain table.) Optimal gain determining section that determines the optimal gain from the inside. It consists of 18. The optimum steering amount calculating section 19 to which the optimum gain determining section 18 is connected inputs the estimated course direction signal ψ, the estimated constant turn rate signal ψ, and the set course signal ψno, and adjusts the hull direction on the set course and set turn rate. Command rudder angle Uδ to steer rudder 9 so that 1 is on board! .

is calculated and output to the steering gear 8.

With such a configuration, the problems of the prior art described above can be solved, and the optimal control gain for the hull can be determined online. That is, even if the hull characteristics such as the hull mass change due to a change in cargo or ballast, the control gain can automatically follow the change, allowing stable steering.

Moreover, even when changing course, the course can be changed without overshooting. Effects such as this can be obtained.

<Problems to be solved by the invention> However, the above-mentioned prior art has (1): Since the rudder angle signal is input, it is expected that the gain can be adjusted to some extent in response to changes in sea conditions; Since external disturbances such as waves cannot be identified, it is not possible to adjust the true optimum gain (that is, to reduce the yawing caused by the disturbance converted into a steering angle). In other words, adaptive control can be performed for hull characteristics such as changes in hull mass, but desirable control characteristics and fuel efficiency cannot be maintained against large changes in sea conditions such as wave disturbances. On the contrary, it was found that it deteriorated. Therefore, in cases where the vehicle is greatly influenced by sea conditions such as wave disturbance, the above-mentioned prior art cannot expect to improve the best course keeping characteristics or fuel efficiency. Therefore, the gain adjustment for the influence of sea conditions such as wave disturbance is still manually performed by the navigator based on his experience, which is a burden to the navigator. There is a problem.

Means for Solving the Problems〉 (Objective of the Invention) The present invention has been made in view of the above-mentioned problems. The purpose of the present invention is to provide a marine autopilot that is capable of automatically performing optimal steering by providing a disturbance characteristic control section that performs disturbance correction calculations that are not affected by the effects of steering angles, and outputs optimal steering angle signals. do.

(Concept of the Invention) Changes in sea conditions, which are wave disturbances acting on the hull, can be known by estimating the state of change and tracking this estimated value. That is, compensation for errors caused by wave disturbance can be made by feeding back the tracking results. As a result, it is possible to prevent deterioration in control characteristics and fuel efficiency caused by disturbances that have a large effect on the hull, including wave disturbances.

By the way, in order to estimate wave disturbance, a mathematical model for wave disturbance is created, and the turn rate and heading angle estimated based on this mathematical model and the turn rate and heading angle measured based on the actual wave disturbance are used. All you have to do is find the difference between the two and calculate the difference from time to time so that this difference is minimized.

Generally, an actual wave disturbance is interpreted as a superposition of a low-frequency sine wave to a high-frequency sine wave, plus a random wave. However, in order to estimate waves at all frequencies, all frequencies must be mathematically modeled, incorporated into a computer, and processed in real time, which is impossible. Therefore, in reality, among the wave disturbances that affect the ship's hull, components with high power within the controllable frequency band, such as the first. The second wave (if there is another component with large power, it may be possible to pick up that component as well) is selected and estimated (the measured turn rate is Fourier transformed and frequency analyzed), and feedback is supplemented. That is,
The response frequency of the hull is calculated from the estimated hull parameters (in the example described below, the wave frequency to be estimated is calculated from the response frequency and the wave frequencies of the first and second waves in the low frequency region). do).

The present invention is constructed from such a concept.

The configuration of the marine autopilot of the present invention that embodies these will be described below.

(Structure of the Invention) The marine autopilot of the present invention is composed of a hull dynamic characteristics calculation section and a disturbance characteristics calculation section, and is configured to output an optimal steering angle signal corresponding to all disturbance elements acting on the hull to the steering gear. did. Here, the hull dynamic characteristic calculation section and the disturbance characteristic calculation section are configured as follows.

In the ship dynamic characteristics calculation section, the ship's heading signal.

A hull characteristic estimation calculation unit calculates hull parameters, which are estimated values of hull characteristics, from the turn rate signal, ship speed signal, and rudder angle signal, and also calculates the hull parameters that are included in the heading signal from the heading signal, turn rate signal, and rudder angle signal. High frequency components harmful to internal steering of various disturbance elements are estimated and removed by a hull motion estimation calculation unit, and the dynamic characteristics of the ship are calculated and outputted to a disturbance characteristic calculation unit described below.

The disturbance characteristics calculation section receives each output of the hull dynamic characteristics calculation section, as well as the ship's heading signal, turn rate signal, and rudder angle signal, and in order to output an optimal rudder angle signal. , settling determination section.

It is composed of a comparison determination section, a gain reset command section, a wave disturbance frequency determination section, a sea condition determination section, and a disturbance correction calculation section. Note that each of these parts is related to the following configuration.

The wave disturbance acting on the hull is estimated by the wave disturbance estimation calculation unit which receives the wave disturbance frequency from the wave disturbance frequency determination unit (described in detail below) including the heading signal, turn rate signal, and rudder angle signal (described in detail below). The gain reset command signal from the reset command unit is also input, but it is not relevant when performing estimation calculations). The progress of the estimation calculation (whether or not the result has reached a settling state) of the wave disturbance estimation calculation section is determined by the settling determination section to which the heading signal and the turn rate signal are simultaneously input.

On the other hand, the estimation calculation result of the wave disturbance estimation calculation section is led to a comparison judgment section into which the heading signal and the turn rate signal are input, and is compared with the wave disturbance estimation model.

A wave disturbance frequency that can be controlled by the ship is calculated and determined by a wave disturbance frequency determining section to which the comparison determination result, the ship parameters, and the turn rate signal are connected. This determined wave disturbance frequency is fed back to the wave disturbance estimation calculation section and output to the sea condition determination section. The sea condition determination section determines the state of the waves based on the wave disturbance frequency and the turn rate signal, and outputs the result to the disturbance correction calculation section.

The disturbance correction calculation unit, to which the hull dynamic characteristics estimation calculation unit, the settling determination unit, and the sea condition determination unit are connected, performs correction calculations for disturbances in the wave dynamic characteristics acting on the ship and disturbances generated from the ship itself such as cargo, and generates an optimal steering angle signal. is output to the steering gear.

<Embodiments of the Invention> Specific embodiments of the above-described configuration will be described below with reference to the drawings.

FIG. 1 is a block diagram of a marine autopilot according to the present invention, and FIG. 2 is a 70-seat diagram of FIG.

In FIG. 1, parts and functions that are the same as those in FIGS. 10 and 11 are given the same numbers and symbols, and their explanations will be omitted.

In FIG. 1, reference numeral 11A denotes a hull dynamic characteristics calculation section, which is composed of a hull characteristics estimation calculation section 12 and a hull motion estimation calculation section 15' (the course deviation shown in FIG. 10 is obtained within this circuit); 20 calculates the disturbance elements and generates the optimum steering angle signal U.
This is a disturbance characteristic calculation unit that outputs δ. The disturbance characteristic calculation unit 20 is connected to the hull dynamic characteristic calculation unit 11A, and receives the heading signal ψ, turn rate signal ψ, and steering angle signal δ, calculates the optimum steering angle, and generates the optimum steering angle signal Uδ. In order to output, the wave disturbance estimation calculation unit 21 and the settling determination unit 2
2, a comparison determination section 23, a gain reset command section 24, a wave disturbance frequency determination section 25, a sea condition determination section 2G, and a disturbance correction calculation section 27.

Below, each of these parts will be explained in more detail based on Figures 1 and 2.
Explain in detail.

(Wave disturbance estimation calculation unit 21) The wave disturbance estimation calculation unit 21 calculates the heading signal ψ, the turn rate signal ψ, the rudder angle signal δ, and the wave disturbance frequency determined by the wave disturbance frequency determination unit 25, which will be described in detail below. The magnitude of the wave disturbance Wd at a frequency that can be controlled by the hull 1 is estimated and calculated. This can be expressed as an arithmetic expression as follows.

Among the waves that affect the hull, the first wave (Ad+5in(ω, t
+θI)), second wave (Ad2sin (ω2t+θ2
)) The model for the wave disturbance Wd that should be estimated is Wd (t)-Ad, sin (ω+t+θ1)
+Ad2s in (O2t+θ2) =・(1)
becomes. However, AdI and Adz are the amplitudes of wave disturbances to be estimated, and θ1. θ2 is the phase of the wave disturbance to be estimated. Here, the model of wave disturbance Wd is differentiated, and wave disturbance Wd
To find the speed of movement, Wd(t) = Ad+ W+ CO5(ω1t+θ1)+Ad2W2
CO8(ω2t+θ2)...(2) is obtained. this(
+), wave disturbance estimated value (yawing) Wd(t) set based on equation (2), wave disturbance estimated value (rudder angle due to disturbance) W(j(t), Be = (A d + W+ COS (ωH' T
+U+ )+ 5 + V 嘗 + K52
Wc1(t) to V2. However, AdI and Ad2 are wave disturbance Ki+
, Ks2 are each estimated parameter (Wd, AdI, Ad2 .
θ1. The estimation gain determined to minimize the variance of the estimation error with respect to θ2), t is the time.

Furthermore, the estimated amplitudes Adl and Ad2 of the wave disturbance Wd are expressed as h. However, for Kg+~? 2 is the amplitude Ad1
．． It is an estimation gain determined to minimize the variance of estimation errors regarding Ad2. Also, the estimated phase θ of wave disturbance
1. θ2 is to , to θ2−. 9+(ψ-ψ)+92(Φ-ψ)...(
7). However, Ks I~KI2 is the amplitude θ1
is an estimated gain determined to minimize the variance of estimation errors regarding °O2.

As described above, the heading signal φ, the turn rate signal i, the rudder angle signal δ, and the wave disturbance frequency ω1. ω2 estimates the magnitude of wave disturbance at a frequency that is controllable for the hull 1 based on these estimation formulas, and outputs the estimation result to the settling determination unit 22 and the comparison determination unit 23.

(Settling Judgment Unit 22) The settling judgment unit 22 is connected to the wave disturbance estimation calculation unit 21, receives the heading signal φ and the U-turn rate signal ψ, and determines whether the wave disturbance estimation has reached a stable state. Determine whether

It is assumed that a stable state has been reached: ■The average of two-wave disturbance Wd, estimated gain Ks+, and Kzz is 1.
The rate of change in the current is monitored, and this is determined by the set value ε set in advance for each class of ship and each sea condition level. The mean square root (hereinafter rRMsJ (Root
When the relative change rate of (abbreviated as Mean 3 square) becomes less than or equal to a set value of 87, the following is true. This will be explained below using arithmetic expressions.

Regarding ■, it is as follows.

The average of 51 samples for N estimated gains from current time TR to past time Tl2-N is 16 to 7 + (TR), which is 2 to 14 i - 1 " (TR n -. This estimated gain The average of Ks+ is 11 and 5+ (TR
) is 5 + - (TR+1), is K5
+ ′(TR++ )=l (K5 + (T
Q++ )-×1-+ (TR) ) / K'5
Yu(TR)I...(9). Here, K51-(
TR+1) is K5 + −(TR++) ≦6K
! + -00). If the above relationship is represented in a diagram, it will be as shown in the wave estimation gain characteristic diagrams in FIGS. 3(A) and 3(B). Similarly, 82 sample average 1llI for N estimated gains from current time TR to past time TR-N is 12 (Tll).
)-(1/N), Σ is 52 (T+)...(11) and becomes 1-14. This estimated gain has an average value of 52 (TR)
52- (TR+) is the relative change rate of X52-
(TR+1)”l (X52 (TR++
)-X77(TR)1/52(TR)l...
・(12) becomes. Here, X52- (TR++)
is 52 for X52-(TR++)≦ε.
It is sufficient if the relationship (13) holds.

Regarding ■, it is as follows.

νRM5(TR), which is the RMS of N observation residuals ν from current time TR to past time Ttt −N, is νRrrs(Ti)=... (14). The relative change rate ν = (TR++) of νRMS (one company), which is the RMS of this observation residual ν, is
Blindness) - 1(ν(TR++)-ν(TR))/νRM s
(TR) i...(+5). Here, C (T
R++) is C(TR++)≦εma
...It is sufficient if the relationship (16) holds. If the above relationship is expressed in a diagram, the change characteristic diagram of the turn rate with respect to time of No. 4111<A) to (0) and the RM of the observation residual
This is a characteristic diagram of the rate of change of S.

When these conditions ■ and ■ occur, it is assumed that a stable state has been reached, and it is determined that estimation of the wave disturbance has been completed.

When the estimation is completed, the wave disturbance estimation value (yawing) signal Wd(t) and the wave disturbance estimation value 1a (rudder angle due to disturbance) signal Wd(t) of equations (2) and (3) are subjected to disturbance correction calculation. output to section 27.

(Comparison/judgment unit 23) The comparison/judgment unit 23 is connected to the wave disturbance estimation calculation unit 21, receives the heading signal ψ and the turn rate signal ψ, and estimates the actual wave disturbance and the wave disturbance set in advance. Outputs the comparison results with the estimated model.

By the way, even if the estimation of wave disturbance is completed using equations (1) to (16), as shown from Tz onwards in Figure 4, if the sea conditions change, the wave disturbance level also changes, so there is a difference between the estimated model and the actual one. There is a difference between the wave disturbance and the wave disturbance. In addition, the calculation results of the hull dynamic characteristics calculation unit 11 and each estimated gain of equations (1) to (1) become minute values once they reach the settling region, and since they maintain these minute values thereafter, they are no longer estimated. The problem is that abilities are lost.

Therefore, the comparison/judgment section 23 inputs the output of the wave disturbance estimation calculation section 21, the heading signal ψ and the U-turn rate signal Φ, and compares the actual wave disturbance with the estimated model (for example, here, the result is a mismatch). to automatically detect, i.e.,
The model discrepancy is determined by the observation residual ν” (TM) (= [(1/M)Σ(ψ(Tl)
−ψ(T+))2]1/2)),
It has a function of resetting the above-mentioned minute estimation gain to a normal value and re-estimating the wave disturbance in that sea state.

That is, if the hull 1 enters another ocean current after the estimated settling, the observation residual ν'' (TM) after the estimation starts to increase with time (see FIG. 4(D)). sets the upper limit setting value! to this increase value, and this upper limit setting 1
If it exceeds 11[l, it is determined that the estimated model has significantly deviated from the actual waves, and judgment No. 18 is sent to the gain reset command unit 24.
Output to.

Note that the comparison/judgment unit 23 determines whether the model is inconsistent or not by calculating the autocorrelation function of the observation residual ν'' (TM) after estimation. Since it matches the wave of , the observation residual after estimation ν”(TM)
Calculate and monitor the correlation I31'1 loss, and this is the upper limit setting value! If it exceeds 1, it may be determined that the fixed model does not fit.

(Gain Reset Command Unit 24) The gain reset command unit 24 inputs the determination signal of the comparison determination unit 23, and if the comparison result does not match, resets and returns the above-mentioned minute estimated gain to a normal value (estimated hull Estimated gains of all parameters except parameters α and β (for example, return 51 to 92 in equations (3) to (7) to their initial values), and re-estimate the wave disturbance Wd of the hull 1 in that sea state. Such a command signal is fed back to the wave disturbance estimation calculation section 21 and the hull motion estimation calculation section 15'.

Although it is preferable to install the gain reset 24 because of the property of constantly holding the optimum estimated value, it may be omitted as shown by the broken line in the figure, and is not necessarily a necessary function. If the gain reset 24 is omitted, a signal when the comparison results do not match is fed back to the wave disturbance estimation calculation unit 21 and the hull motion estimation calculation unit 15-.

(Wave disturbance frequency machine 6 constant section 25) When the sea condition changes, the wave disturbance frequency inputs the estimated hull parameters α and β from the hull characteristic estimation calculation section 12, the turn rate signal ψ, and the judgment signal from the comparison judgment section 23. The determining unit 25 determines the maximum value of the low frequency band in which the hull 1 is capable of ill II (or capable of responding) under the sea condition (tla that most affects the course keeping performance of the hull) and if! A controllable wave disturbance for the hull 1 is determined from the frequency of the value of 2. This can be expressed as an arithmetic expression as follows.

Turn rate y (t>) including irregular noise of hull 1 (average value is O) is 31 (t) - small (t) + 17 (t)...
(17). Fourier transform this value. That is, P
(n)-<1/T)・urL/y(t)e-”dt・(1z)-TA. However, n-0, ±1.±2.

The wave disturbance frequency determining unit 25 determines the set of (17) y(
The operation of n) is performed when the model mismatch message from the comparison/judgment unit 23 is sent.
If it is executed without fail after receiving the signal, the frequency spectrum related to the turn rate ψ can be obtained, and the wave disturbance can be determined from the frequency of the maximum value and the second value of the easily controllable low frequency band. If the above relationship is plotted, it will look like the controllable wave disturbance frequency band characteristic diagram in FIG. 5.

In Fig. 5, F is a Fourier transform unit that calculates equation (17)′, W is a wave disturbance frequency calculation unit that inputs the estimated hull parameter ♂ and calculates the wave disturbance frequency band ωC (-α), and ωε is a Controllable low frequency band.

Note that the above is the first. Although only the second frequency component is concerned, it is not limited to this. That is, after Fourier transformation, set the frequencies after the third frequency,
Wave disturbance may also be estimated.

In this way, further feedback PII 9;D
The characteristics will improve.

(Sea Condition Determining Unit 2G) If the sea conditions change, the state of the wave disturbance Wd also changes, and the magnitude of the wave disturbance Wd must be estimated again, and the wave disturbance feedback must also be changed.

The sea condition determination unit 26 is provided to realize this automatic determination of the sea condition level again. That is, the sea condition determination unit 26 receives the turn rate signal φ and the wave disturbance frequency ω blind and ω2 determined by the wave disturbance frequency determination unit 25.
determines the state of the ocean. That is, the sea condition determination unit 26 determines (1
7) Calculate the following power spectral density 5(n) from the equation.

S (n>-1y(n)12 ・ (18
) The sea conditions level at the time is judged and determined based on whether the maximum value of this power spectral density S(n) is less than or more than a predetermined sea condition setting value. (It is also possible to use data obtained by Fourier transforming the wave disturbance Wd.)

Currently, the current state of the sea conditions is: ■ A mirror-like sea condition with a visible wave height of about 0 to 0.1 m (hereinafter referred to as rcALMSEAJ); ■ A sea condition with slightly high waves with a visible wave height of about 2.5 to 4 m (hereinafter referred to as rROUGH8EAJ) (hereinafter referred to as rV
(called ERYROLIGH5EAJ), ■visual wave height is 6
extremely rough sea conditions (rl-11GHROU)
GH5EAJ), the judgment of the sea state level at that time is: ■: In the case of CALM SEA, MAX [3(n)] ≦Φwd o
-(19), so the wave disturbance is estimated in principle.

■: In the case of ROLJGHSEA, Φwdo <MAX [8(n)]≦Φwd + ・”
< 20), so we estimate the wave disturbance.

■: VERY ROLJGH5EA (7), if Φ
wd I <MAX [8(n>] ≦Φwd2 ・
” (21), so we estimate the wave disturbance.

■: In the case of l-11GHROUGHSEA, Φwd
2 <MAX [S (n)] ・=
(22) Therefore, in principle, estimation of wave disturbance is not performed for the safety of the ship.

Based on these judgment results, the determined wave disturbance frequency ω is
10. ω2o is output to the disturbance correction calculation unit 2γ.

(Disturbance correction calculation unit 27) By the way, the equation of motion of the hull is ψ(t)−−αΦ(1)+βUδ1°(1)
23). However, α and β are parameters of the hull itself. Since the wave disturbance Wd(t) is obtained by replacing the yawing caused by the disturbance with an equivalent steering angle, the equation (23) is ψ(t)−αψ(t)+βLI6+′ (j)+βWd(t)・...(24)
It can be expressed as That is, the disturbance correction calculation unit 21
By adding the steering angle with respect to the wave disturbance Wd(1) to the commanded rudder angle signal Uδ+'(1:), a steering operation is performed that makes it possible to reduce yawing due to disturbance elements that have a large effect on the hull. That is, the disturbance correction calculation section 2
1 includes a hull dynamic characteristic calculation unit 11A, a settling determination unit 22, and a sea 5.
An optimum steering angle signal Uδ is calculated by correcting the influence of the wave disturbance Wd(t) acting on the hull 1 and the influence of disturbance elements generated by the ship/body itself due to cargo, etc. It is configured to output to the steering gear 8, and performs the following two calculations.

The first is the estimated hull parameters output from the hull characteristic estimation calculation unit 12? , ↑ and the determined wave disturbance frequency ωIO+ω2o, which is the output value of the sea condition determination unit 26, are input to determine the weight matrices IQ and IR of the hull.
Ministry of estimated hull parameters, ? and the determined wave disturbance frequency ω
From Ionω2o, 6°lK7° is calculated online as the optimum control gain based on the weight matrices IQ and IR of the hull in that sea state, and is sent to the estimated wave disturbance estimation from the settling determination unit 22.

Value (yawing) Wd(t), (rudder angle due to disturbance) Wd
Wave disturbance Wd(t) multiplied by (t) and generated in the hull 1
The first steering angle U6A' (
t) is obtained. This first steering angle UδA' (t) is determined by
7° Wd(t) ... (25).

The second is the weight matrix I of the ship in the same sea state.
Based on Q and IR, an optimum control gain of 1° to 5° is calculated online, and this v1 gain is calculated by +' to 5°.
° is multiplied by the estimated course azimuth signal ψ, estimated turn rate signal ψ, set turn rate ψmo, and set course azimuth ψmo to calculate the second steering angle Uδg'' ( This second steering angle L16a' (t) is ◇ LJ6a° (t) = −K +°ψ(t)− by 4°.
ψno(t) K5°f(ψ(t)−ψno(t
> ) d t) −= (26). However, K1° to 5° is the optimum gain. This first steering angle UδA” (t) and the second steering angle Uδ
A′ (t) is calculated by /XI and the optimum steering angle signal Uδ is output to the steering wheel 1j18.

Energy saving evaluation 1lii using the generally known optimal regulator theory has been applied to the technology for obtaining the optimal control gain described above.
An explanation using inter-evaluation IJE called the fl number is as follows.

In general, the evaluation function JE can be defined as r>'+λa(faψodt)'-(27), and the control gain can be obtained by minimizing the value of this evaluation function Jε.

However, T■77 is the root mean square of the course deviation, Uδ2 & the root mean square of the steering angle, (Φ-)2 is the root mean square of the dimensionless turn rate, (fΔψ.dt)2 is the root mean square of the calculated course deviation, λ1. λ2. λ3. λ4 represents the m-shape coefficient, respectively. Here, if the hull motion system is expressed as a state variable, % (t > -1FX (t > +1BLl (t
)'IY (t) -1f-(X (t)
・(28) becomes. However, X (t), Y (
t) is the state vector, the old system line 1fij consists of the parameters α of the hull itself, and the old system line 1fij consists of the parameters β of the hull itself
U(t) is the control vector, and U(t) is the output matrix.

Here, the state vector x (t) is becomes. However, fΔψdt is an integrated value of course deviation.

Also, the state vector Y (t> is as follows.By the way, when the quadratic form evaluation function is J(t), this quadratic form evaluation function J (t) is J (j>=
E [X” (t+ >IP' % (t+)+f
, (X” (t)IQ% (t) +LJ” (t)IRU (t))dt]...(3
1). However, there is a relationship of time t>to, and the IQ, IRG, and tffl are matrixes.

Note that the weight matrix, lR, is a weight matrix (Iff (
It is determined by parameters α and β of the hull itself. however,
(This may be set using another method), and is determined from the weighting coefficient and energy saving evaluation function JC of the hull in the sea state at the determined wave disturbance frequency ωIonω20. Here, the optimal control gain IK z of this system
is calculated using this optimal regulator theory.

That is, the optimal control gain IKz is lKz = R-
'iB''-1P'' - (32) (where IP' is obtained as a steady solution when 1i)-0 of the Katti equation), and the quadratic evaluation function J
The value is such that (t) is minimized.

By the way, since this system captures the disturbance element with an indirect value appearing at the rudder 9, the optimal Irik U gain IK z that minimizes the quadratic form evaluation function J(t>) is determined by the weight matrix Ω, By setting IR to the optimal value for the hull 1, it becomes a value close to the true optimal gain lKz'. That is,
The optimal control gain IKz is IKz ° ': IKz = [K+ ° K2 ° K3 ° Kd ' by 5 °
K6° K7° ] ... (33) That is, the output of each element UL5' (t
)~Uδ7 (t) +”~K for each optimal gain for calculation
The value of V' is set. Note that the optimal control gain IK2 changes only when the parameters α and β of the hull itself and the determined wave disturbance frequency ωIQ+ω2o change.
At this time, a new optimal impeachment gain IKz may be calculated.

From the above, the optimal steering angle signal Uδ(1) is Uδ(1) /to=, [K+ ° φ (t)+ to 2° ψ (1)+
3” ψno (j) + 4 ° ψno
5 degrees f to (j) (ψ (1) −ψmo(t)')
dt=U6', (t)+Uδ2 (t)+Uδ3 (t
) 10Uδ'(t)+U6' (t)+Uδ6 (
t) - U δ 7 (t)
... (3
4). Here, f('ψ'<t)
-ψmo (t>) (jt indicates that the set course heading is subtracted from the course heading, and this is integrated to calculate the integrated value of the course deviation. This is a concrete block diagram of the disturbance correction part in the figure.

fart In FIG. 6, 28 is the estimated hull parameter α.

β and the determined wave disturbance frequency ωIO+ω2o1. which is the output value of the sea condition determination unit 26. : IQ, IR determination operation which determines the weight matrices IQ, IR based on IQ, 29 is connected to the IR determining unit 28, and is the output value of the sea condition determining unit 26, the determined wave disturbance frequency ωIonω20, and the weight matrices IQ, IR. a control gain determination unit that determines the optimal control gain for the sea condition online from the estimated hull parameters h, 6;
30 to 36 are 1 to output Uδl (t) to Uδ7 (t) based on the values determined by the υj control gain determination unit.
7° operation for °~, 31 subtracts the set course signal ψno from the signal ψ to the estimated course direction, and the course deviation Δψ0
38 is an integration section that integrates the course deviation ΔΦ0, and 39 is a subtractor that outputs all of tJt5' (t) to ()δ7 (t) calculated in 1° to Ky' calculation units 30 to 3G. This is an adder unit that adds the sum and outputs the optimum steering angle signal Uδ. Note that the IQ and IR determination calculation unit 28 and the control gain determination unit 2
9 may be set externally. Further, the set course signal Φmo and the set turn rate (t)mo may be input from the outside, may be obtained by providing an internal transmitter, etc., or may be input from the hull dynamic characteristics calculation unit 11A. good.

In addition, in the above-mentioned embodiment, the optimum control gain is +' to 7°.
Explanation 1 is when performing the calculations up to online,
It is not necessarily necessary to do this online; instead, calculate many optimal control gains in advance, store them as a feedback gain table (memory storage format), and use the estimated hull parameters α and β and the determined wave disturbance. It goes without saying that a method may be used in which the frequency is selected based on the frequencies ωt◇ and ω2°.

The configuration shown in FIG. 6 may be implemented using a microcomputer. The configuration in such a case is shown in FIG. 7, which is a functional configuration diagram when configured with a microcomputer.

In FIG. 7, 27A is a disturbance correction calculation circuit composed of a microcomputer, 211 is a calculation device, and 272 is an estimated course direction input interface (hereinafter abbreviated as r/FJ) for inputting an estimated course direction signal ψ. , 273 inputs the estimated hull parameters α and β Estimated hull parameter human power r/F 1274 inputs the set turn rate signal (1) rho Set turn rate human power 1/F 1275 inputs the set course signal ψmo Set course input 17F , 276 is an estimated turn rate human input I/F that inputs a signal ψ to the estimated turn rate.
17 is the judgment wave disturbance frequency manual [/F] which inputs the judgment wave disturbance frequency ωlo + ω2o, 278 is the one-way only memory (ROM), and 279 is the random access memory (R
AM), 280 is a wave disturbance iff fixed value human power 1 which inputs the calculated digital optimum steering angle signal Uδ as an analog signal and inputs the variable wave disturbance estimated value (steering angle due to disturbance) W(1(t))
/F.

The processing procedure of this microcomputer is as follows. Each input signal (α, β, ω10, ω
20) with the previous depression, and if there is no change in Jg, the optimum steering angle is calculated based on the calculation of the disturbance element, and if any one of the input signals changes, a new weight matrix IQ is calculated. , IR is calculated, a new optimum control gain IKz is calculated, a disturbance element is manipulated using this optimum control gain IKz, and an optimum steering angle is further calculated. The above process is repeated.

FIG. 8 shows a flow sheet for expressing the first steering angle UδA'',(t).

FIG. 9 is a block diagram showing an example of a case where it is desired to limit the steering angle. In FIG. 9, 40 is a steering angle limiter, and 41 is a steering angle limit value input 1/F for inputting the steering angle limit 1tlL+. Note that the steering angle limiter Lj may be fixed or variable; of course, even if this steering angle limiter is not provided, it will not affect the performance of an equivalent system.

Although the case where only FIG. 6 is constructed using a microcomputer has been described above, it is easy to construct the other parts using a microcomputer in the same way.

It should be noted that the present invention may have a structure in which a ship speed signal is used, that is, a structure in which the ship speed signal is incorporated into the ship characteristics estimation calculation section to estimate the ship characteristics. In this way, correction values corresponding to changes in ship speed can be obtained, thereby further improving the accuracy of the present system.

<Effect of the invention> The above describes the present invention together with Examples and other Examples. Although we specifically explained the estimated hull parameter α.

β, the estimated course direction signal command, the estimated turn rate signal, ψ, the wave disturbance estimated full (yawing) W'd(t)' calculated by estimating the wave disturbance acting on the hull, and the wave disturbance recommended value (due to the disturbance According to the marine autopilot of the present invention, which is configured to calculate the optimal steering angle for the ship body from the rudder angle) Wd(t) and the determined wave disturbance frequency ωI Otω20 and steer the steering gear, A: Estimate the ship characteristics and waves. Since we have provided an estimation function to
Control can be performed in response to temporal changes in disturbances that degrade the course-keeping performance and fuel efficiency of the hull. In particular, direct feedback of wave disturbances, which was previously impossible, has become possible, so yawing caused by disturbances can be suppressed more than ever before, allowing for accurate rudder control. In addition, since a comparison/judgment function has been added, it is possible to automatically judge whether or not the wave disturbance, which changes drastically over time, has been correctly estimated, and therefore the wave disturbance can be automatically put into direct feedback mode. In other words, even if sea conditions change, mismatches in the model due to this change can be automatically determined, so changes in sea conditions can be known without the need for human judgment. or,
By automatically resetting the estimation gain, it is possible to automatically track and estimate wave disturbances after changes in sea conditions.

B: This system can automatically set the controllable frequency band for all classes of hulls (control gains are calculated in advance for many hull characteristics and stored in memory, so it is possible to automatically set the controllable frequency band for that hull online). In addition, it is possible to automatically determine the sea condition level (degree of roughness) in any sea area (in other words, it is possible to automatically determine the wave disturbance frequency to be estimated in the It'll 1B possible frequency band under any sea condition). can be set automatically). Therefore, this system can accurately estimate the hull response wave disturbance according to the hull type and sea conditions, and can obtain a control amount corresponding to the wave disturbance. Therefore, unlike in the past, the navigator does not have to look at the sea conditions and select the control gain, which reduces the burden on the navigator, and even without an experienced navigator, the navigator can perform the same or better steering. be able to.

C: Highly accurate course-keeping control is possible compared to conventional automatic steering systems, making navigation or navigation in narrow waterways safer.

In other words, since the course can be changed accurately without overshoot under any circumstances, fuel consumption can be minimized while satisfying high course changeability without unnecessary steering while maintaining high safety and reliability. can do.

D = FIG. 12 shows the "evaluation gQ number JE-1" in the prior art.
It is a time response characteristic diagram of the hull when the load is 13J, and the 13th
The figure is a time response characteristic diagram of the hull when the [Evaluation++15 function Jε-48J is used in the present invention.

This J: As is clear, the course deviation Δψ0 of the present invention is smaller than that of the prior art.

Effects such as this can be obtained. That is, course keeping performance is improved, and as a result, both aspects of fuel efficiency can be satisfied.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the marine autopilot of the present invention, Fig. 2 is a flow sheet of Fig. 1, Fig. 3 (△), (B
) is a wave estimation gain characteristic diagram, Figures 4 (A) to (D) are change characteristic diagrams of turn rate with respect to time and RMS change rate characteristic diagrams of observation residuals, and Figure 5 is a controllable wave disturbance frequency. The band characteristic diagram, the concrete block diagram of the disturbance correction calculation section in Fig. 6, the diagram of the construction of the disturbance correction calculation section in Fig. 7, and the wave correction rudder angle in Fig. 8 are shown in Fig. 6. iJg
Fig. 9 is a block diagram showing an example of a case where the steering angle is to be limited; Fig. 10 is a block diagram of a conventional marine autopilot; Fig. 11
The figure is a block diagram of a marine autopilot described in the prior art, and FIG. 12 is a block diagram of a marine autopilot described in the prior art.
Fig. 13 is a time response characteristic diagram of the hull when the evaluation function is JE-48J in the present invention. DESCRIPTION OF SYMBOLS 1... Hull, 12... Hull characteristic estimation calculation part, 15.
... Hull motion estimation calculation unit, 20... Disturbance characteristic calculation unit,
DESCRIPTION OF SYMBOLS 21... Wave disturbance estimation calculating part, 22... Setting judgment part, 23... Comparison judgment part, 24... Gain reset command part, 25... Wave disturbance frequency determination part, 26...i
#j Elephant determination unit, 27... Disturbance correction calculation unit. Figure 8 Figure 7 Figure 1O Figure 12 Procedural amendment (voluntary) January 22, 1985 1 Indication of case Patent application 1987-241
No. 289 No. 2 Title of the invention Marine autopilot 3 Relationship to the amendr's case Patent applicant's office
2-9-32 Nakamachi, Musashino City, Tokyo Name (650) Yokogawa Hokushin Electric Co., Ltd. 4 Agent 5 Date of amendment order 6, drawing subject to amendment 7, ? ili Correct contents (1) Figure 2 of the drawings is corrected as shown in the attached figure.

Claims (3)

[Claims] (1) In a marine autopilot configured to obtain a steering angle signal optimal for a ship to be controlled based on signals such as a heading signal, a turn rate signal, and a rudder angle signal, the heading signal, the turn rate signal, and the a ship dynamic characteristics calculation unit that inputs a rudder angle signal, etc., calculates an estimated ship parameter, an estimated course direction, and an estimated turn rate, and outputs an estimated ship parameter, an estimated course direction signal, and an estimated turn rate signal; When a calculation unit is connected, the heading signal, the turn rate signal, and the rudder angle signal are input, and waves acting on the hull are calculated from the estimated hull parameters, the heading signal, the turn rate signal, and the rudder angle signal. Estimate the disturbance and obtain the determined wave disturbance frequency and estimated wave disturbance value,
The estimated hull parameters inputted from the hull dynamic characteristics calculating section. Based on the estimated course direction signal, the estimated turn rate signal, the determined wave disturbance frequency, and the estimated wave disturbance value, a correction calculation is made for disturbance elements that have a large effect on the hull, and the optimum steering angle signal is output. A marine autopilot characterized by comprising a disturbance characteristic calculation section and the following. (2) The hull dynamic characteristics calculation section includes: a hull characteristics estimation calculation section that calculates and outputs an estimated hull parameter that is an estimated value of the hull characteristics from the heading signal, the turn rate signal, and the rudder angle signal; and the bow A hull motion estimation calculation section that estimates and calculates the motion of the hull from the azimuth signal, the turn rate signal, and the rudder angle signal and outputs the estimated course direction signal and the estimated turn rate signal. A marine autopilot according to claim 1. (3) The disturbance characteristic calculation unit estimates and calculates the magnitude of wave disturbance acting on the hull at a frequency that can be controlled by the hull from the heading signal, the turn rate signal, the rudder angle signal, and the wave disturbance frequency signal. The wave disturbance estimation calculation unit connected to the wave disturbance estimation calculation unit receives the heading signal and the turn rate signal, and determines whether the estimation of the wave disturbance estimation calculation unit is completed. A settling determination unit that outputs a wave disturbance estimated value is connected to the wave disturbance estimation calculation unit, and inputs the heading signal and the turn rate signal to estimate the actual wave disturbance and wave disturbance acting on the hull. a comparison/judgment unit that outputs a comparison result with an estimated model; and inputs the turn rate signal, the estimated hull parameters, and the comparison signal of the comparison/judgment unit, determines a wave disturbance frequency, and outputs the wave disturbance frequency signal. a wave disturbance frequency determination section; a sea condition determination section that inputs the turn rate signal and the wave disturbance frequency signal, determines the sea state from the state of the wave disturbance, and outputs the determined wave disturbance frequency; and the ship dynamic characteristic calculation. and a disturbance correction calculation part to which the settling determination part and the sea condition determination part are connected, and which performs a correction calculation for disturbance elements acting on the hull and outputs the optimum steering angle signal. A marine autopilot according to claim 1.