JPH0471755B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a marine autopilot, and in particular controls a rudder gear with a large dead zone with respect to a commanded rudder angle by setting an optimal reference level. The present invention relates to a marine autopilot that achieves energy-saving steering by increasing the sensitivity to follow angles and thereby reducing the steering resistance of the vessel.

<Conventional Technology> Hereinafter, the conventional technology will be explained with reference to the drawings. FIG. 8 is a block diagram showing the configuration of a conventional marine autopilot.

In FIG. 8, A is a servo mechanism of a mechanism that drives the rudder 1 of the ship. This servo mechanism A is
A three-way switching valve 3 having electromagnetic valves 2 on the left and right sides, and a servo cylinder 4 that operates the cylinder left and right by supplying oil pressure in different directions by the operation of the three-way switching valve 3.
A variable discharge pump 5 is operated by the movement of the cylinder of the servo cylinder 4, and hydraulic pressure is discharged to the servo cylinder 4 and the variable discharge pump 5 through the three-way switching valve 3 driven by the motor 7. The hydraulic pump 6 has a cylinder 8 that changes the direction and amount of operation of the steering gear 1 according to the amount of oil discharged by the variable discharge pump 5. Reference numeral 9 denotes a steering angle detector that detects the amount of operation of the steering gear 1 and outputs an actual steering angle signal μ. Reference numeral B designates a servo amplification unit that outputs drive signals i, j for driving the servo mechanism A from a deviation signal (θ-μ) between the command steering angle signal θ and the actual steering angle signal μ. This servo amplification unit B includes a subtraction circuit 10 that inputs a command steering angle signal θ and an actual steering angle signal μ, which are angle signals within 35 degrees left and right, and outputs a deviation signal (θ−μ), and a subtraction circuit 10 that outputs a deviation signal (θ−μ). A reference level setting unit 11 that outputs a reference level signal l ₀ considering the accuracy angle ε (for example, 0.3°)
Then, input the deviation signal (θ-μ) and the reference level setting value l ₀ to determine the operating direction of the rudder 1 (for clockwise rotation and counterclockwise rotation).
and a pair of relays R ₁ and R ₂ that output drive signals i and j corresponding to the comparison results of the comparison circuit ₁₂ to the servo mechanism _A. The solid state relay section 13 (hereinafter abbreviated as "SR") is comprised of a solid state relay section 13 (hereinafter abbreviated as "SR").

FIG. 9 is a time chart for explaining the operation of FIG. 8.

From FIGS. 8 and 9, for example, when the command steering angle signal θ changes by 4° from the state where the deviation signal (θ−μ) is zero at time t ₁ in the comparator amplifier Q ₁ , for example,
When it is detected that the reference level set value _l0 , which is set to a small value of 1.3°, has been exceeded, the solenoid valve 2 connected to the relay _R1 is activated, the three-way switching valve 3 switches the hydraulic flow path, and the servo The tilting angle of the variable discharge pump 5 mechanically connected to the cylinder 4 is controlled, and the cylinder 8 is driven by the hydraulic pressure discharged according to the tilting direction of this tilting angle, and the steering gear 1 is outputted as a deviation signal (θ-μ). Rotate in the direction to decrease. This rotation of the rudder 1 is detected by the rudder angle detector 9, fed back to the subtraction circuit 10, and subtracted from the command rudder angle signal θ, resulting in a deviation signal (θ−
When μ) falls within the reference level set value l ₀ at time t ₂ , the solenoid valve 2 becomes de-energized, the 3-way switching valve stops the flow of hydraulic pressure, the servo cylinder 4 returns to the neutral position, and the variable discharge When the tilting angle of the pump 5 also returns to the neutral position, the hydraulic pressure flow to the cylinder 8 is stopped, and the rotation of the steering gear 1 is stopped. but,
As shown in Fig. 9, due to the characteristics (inertia) of the equipment of the servo mechanism A, etc., there is a time delay between when the solenoid valve 2 becomes de-energized and when the rotation of the rudder 1 stops. Since overshoots such as _{α 1} and α ₂ occur, the rudder 1 converges to a constant value while hunting and stops. In order to suppress this hunting, this technique is configured so that the reference level setting value l ₀ connected to the comparators Q ₁ and Q ₂ is set larger than the overshoot amount.

<Problems to be Solved by the Invention> By the way, if the reference level setting value _l0 is set to a relatively small value such as 1.3°, the amount of overshoot will increase and hunting will occur as shown in Figure 9. On the other hand, if the reference level setting value _l0 is set to a large value such as 4° or 5° in order to avoid this hunting, the steering gear 1 will have poor tracking accuracy with respect to the commanded rudder angle, and therefore the steering resistance will decrease. This causes an increase in energy consumption and impedes energy-saving steering. It would be good if this reference level setting value l ₀ could be set to the optimum state, but since the optimum value of the reference level setting value differs slightly for each steering device, it is difficult to set the optimum value with conventional technology. . There is a problem.

The present invention has been made in view of the problems of the prior art, and it obtains an optimal reference level setting value and a minimum steering angle command signal that drives the rudder at the minimum steering angle, even if overshoot. The purpose of the present invention is to provide a marine autopilot that improves the followability of an actual steering angle to a commanded steering angle even with a large mechanism, reduces steering resistance, and realizes energy-saving steering.

<Means for Solving the Problems> The marine autopilot of the present invention comprises a servo mechanism for achieving the above-mentioned purpose and a servo amplifier unit that outputs a drive signal to the servo mechanism. A minimum steering angle command is output from the command unit, inputs a deviation signal, and learns a basic reference level value from the overshoot amount of the rudder in the overshoot learning unit, and then drives the rudder to the minimum steering angle from the deviation signal. A learning section configured to learn and output a signal by the minimum steering angle control section is provided in the servo amplifier section, and after the learning section completes learning, a standard is set based on the basic reference level value from the overshoot learning section. The level setting value and the deviation signal are compared by a comparison circuit, and when the deviation signal is within the reference level setting value and greater than the minimum steering angle, the rudder is driven by the minimum steering angle command signal. .

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings. In the following drawings, parts that overlap with those in FIGS. 8 and 9 are given the same numbers and their explanations will be omitted.

FIG. 1 is a block diagram of a marine autopilot according to the present invention.

In FIG. 1, reference numeral 14 denotes a learning section that is provided in the servo amplifier C and learns the characteristics of the servo mechanism A when the servo amplifier C and the servo mechanism A are coupled. The learning section 14 includes a learning mode command section 14a that inputs a learning start signal S and outputs a learning mode signal, and a learning mode command section 14a that inputs a deviation signal (θ-μ) and outputs a learning mode signal to the steering gear 1.
Reference level setting unit 11 from the overshoot amount of
Overshoot learning unit 14b that learns the basic reference level value that is the basis of the reference level setting value l of 0.
and a minimum steering angle control section 14c that inputs a deviation signal (θ-μ), learns and outputs a minimum steering angle command signal for driving the steering gear 1 at the minimum steering angle. Overshoot learning section 14b and minimum steering angle control section 14c
The outputs are led to OR gates 16a, 16b via switching elements 15a, 15b. The learning mode signal from the learning mode command section 14a is sent to the switch 17.
a and 17b are turned on and off, and when the learning section 14 is in the learning operation, the output from the comparison circuit 12 is turned off.

FIG. 2A is a block diagram of the hardware configuration of the servo amplification section C when the learning section 14 is, for example, an analog + microprocessor, and FIG. FIG. 3 is a block diagram of the hardware configuration.

In FIGS. 2A and B, 18, 180 is an arithmetic function (CPU), 19, 190 is a read-only memory (ROM), 20, 200 is a random access memory (RAM), and 21, 210 is an input for learning start signal S. switch input interface, 22,
220 is a command rudder angle input interface for inputting the command rudder angle signal θ, and 23 and 230 are actual rudder angle signals μ.
The actual steering angle input interface 24 outputs various signals (here, the switch 17a,
Learning mode signal output to AND gates 170a and 170b instead of 17b and reference level setting section 1
(basic reference level value output to AND gate 10 and minimum steering angle command signal output to AND gates 16a, 16b)
Output interface, 240 is drive signal i, j
It is an output interface that outputs .

It should be noted that the servo amplifier is not limited to the case where a microprocessor is used as shown in FIGS. 2A and 2B, and it goes without saying that it may have a discrete circuit configuration as in the prior art.

By configuring the servo amplifier C in this way,
The comparison circuit 12 compares the standard level set value l set based on the basic standard level value from the learning unit 14 and the deviation signal (θ−μ) after the learning operation and after the completion of the learning operation, and generates the deviation signal (θ -μ) is within the reference level setting value l and the minimum rudder angle δ or more, the rudder 1 is driven with the minimum rudder angle command signal. This will be explained in detail below using .

<<Learning mode>> When the learning start signal S is input, the learning mode command section 14a outputs a learning mode signal and switches switch 1.
7a and 17b to cut off the output of the comparator circuit 12, and also manually or, for example, by inputting the learning start signal S.
and learning mode signal automatically switching element 1
5a and 15b are switched to the overshoot learning section 14b side.

For example, as shown in FIG. 4, the overshoot learning unit 14b changes the commanded steering angle signal θ so that the steering angle, which was balanced at -30° at time _t1 , becomes +30°, and the deviation is zero. The SR 13 is turned on and the steering gear 1 rotates so that the actual steering angle signal μ follows the commanded steering angle signal θ. When the deviation becomes zero at time _t2 , the solenoid valve 2 becomes non-energized. On the other hand, the rudder 1 overshoots due to inertia. The overshoot amount at this time, that is, the basic reference level value is expressed as η and is learned as 3° in FIG. 4, and is output to the reference level setting section 110. Note that the reference level setting value l is, for example, the basic reference level value η (3°) set by the reference level setting unit 11.
0 in the variable storage batteries 110a ₁ and 110a ₂ , and the target tracking accuracy angle ε (for example, 0.3°) of the device is set in advance in the variable storage batteries 110b ₁ and 110b _2.
together with the reference level setting value l (in this case η+ε=
3.3°).

When the learning of the overshoot learning section 14b is completed, the switching elements 15a, 15b are switched to the minimum steering angle control section 14c side by, for example, an end signal, and learning of the minimum steering angle control section 14c is started.

In the minimum steering angle control section 14c, for example, the fifth
As shown in the figure, when the deviation signal (θ-μ) is zero in equilibrium at a steering angle of 1°, learn the minimum steering angle command signal that is sufficient to drive (rotate) the steering gear 1 by the minimum steering angle. In order to achieve this, the pulse width τ is stepped up from a narrow pulse width to wide pulse widths τ ₁ , τ ₂ , τ ₃ in order, and the actual steering angle signal μ is monitored to ensure minimum control when the rudder 1 starts rotating. Learn the possible steering angle amount (minimum steering angle amount) and the minimum controllable pulse width at that time. FIG. 5 shows that the minimum steering angle amount δ (=0.5°) was able to be learned when the minimum controllable pulse width τ ₃ was used.

When the learning of the minimum steering angle control section 14c is completed, for example, an end signal is output to the learning mode command section, and the learning end signal is outputted from the learning mode command section 14a to operate the switches 17a and 17b.
2 and the OR gates 16a and 16b.

This completes the learning in the learning section 14.

Note that the learning order may be such that the minimum steering angle control section 14c is learned first, but in this case, the switching elements 15a,
15b is the minimum steering angle control unit 1 in the final state (normal time).
It needs to be on the 4c side.

<<Normal Operation>> The normal operation will be explained using FIGS. 6 and 7.

Figure 6 shows that the commanded rudder angle signal θ is changed from zero at rudder angle 0° to 15° at time t ₁ , and the actual rudder angle signal μ is set to the reference level at time t ₂ . value l
= within 3.3°, and after that the deviation signal (θ-
The case where μ) is, for example, 0.4° and the minimum steering angle δ is less than 0.5° is shown.

Next, another example will be explained using FIG.

Rudder angle 0° at time t ₁ (deviation signal (θ−μ) is zero)
The command rudder angle signal θ is changed from the state to 4°, and the time
At time t ₂ , the actual steering angle signal μ becomes within the reference level setting value l = 3.3°, and at time t ₃ , the actual steering angle signal μ reaches an equilibrium state of 2.9°, that is, the deviation signal (θ − μ) For example, if the minimum steering angle δ is 1.1° or more than 0.5°,
At time t ₄ , the minimum steering angle signal (pulse width is 2×τ ₃ from 1.1/0.5→2) is output from the minimum steering angle control unit 14c to drive the steering gear 1. Therefore, in this example, the deviation is less than the minimum steering angle δ (0.1°), and the steering gear 1 stops rotating. Now, at time t ₅ , the commanded rudder angle signal θ changes from rudder angle 4°.
When the steering angle is changed to 3.2°, the minimum steering angle signal with a pulse width (from 0.7/0.5→1) of 1×τ ₃ is output from the minimum steering angle control unit 14c to drive the steering gear 1, and the deviation is the minimum steering angle δ. It will be below (0.2). Therefore, the rudder 1 stops rotating. Thereafter, such follow-up operation is continuously repeated.

Incidentally, in the case of time _t4 , the minimum steering angle signal _τ3 may be stepped up individually and follow-up control may be performed while checking the responsiveness thereof.

<Effects of the Invention> As described above in detail with reference to the embodiments, the learning section calculates the basic reference level value, which is the basis of the reference level setting value, the minimum steering angle amount, and the pulse width required for the minimum steering angle. Learn the minimum steering angle command signal that is,
After the learning is completed, a comparison circuit compares the standard level set value set based on the basic standard level value and the deviation signal, and if the deviation signal is within the standard level set value and is greater than the minimum rudder angle, the rudder is operated using the minimum rudder angle command signal. According to the marine autopilot of the present invention that drives a marine vessel, hunting due to overshoot is eliminated, so energy-saving steering can be achieved by reducing the steering resistance of the vessel. That is, since the accuracy of following the commanded rudder angle during automatic steering is improved, the amount of rudder angle can be reduced, and the hull resistance generated by the rudder gear is reduced. Further, as the automatic steering reference level setting value becomes smaller, the responsiveness to the commanded steering angle is improved and the delay in the control loop is reduced. Therefore, yawing of the ship is reduced, course keeping performance is improved, hull resistance due to yawing is reduced, and energy-saving steering can be performed. There is an effect.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a marine autopilot according to the present invention, Fig. 2 is a block diagram of a case where the servo amplification section is configured with a microprocessor, and Fig. 3 is a block diagram of a marine autopilot according to the present invention.
The figure is the flow sheet of Figure 1, Figures 4 to 7 are time charts for explaining Figure 1, Figure 8 is a block diagram of a conventional marine autopilot, and Figure 9 is an explanation of Figure 8. This is a time chart for. A... Servo mechanism, 9... Rudder angle detector, B, C... Servo amplifier section, 10... Subtraction circuit, 11, 110... Reference level setting section, 12... Comparison circuit, 14... Learning section.

Claims (1)

[Claims] 1. A servo mechanism for a mechanism that drives a rudder of a ship;
In a marine autopilot comprising a servo amplification section that compares a deviation signal between a commanded steering angle signal and an actual steering angle signal with a reference level setting value using a comparison circuit and outputs the comparison result to the servo mechanism, a learning mode signal is transmitted. an overshoot learning section that inputs the deviation signal and learns a basic reference level value from the overshoot amount of the rudder, and an overshoot learning section that inputs the deviation signal and adjusts the rudder to the minimum A learning section comprising a minimum steering angle control section that learns and outputs a minimum steering angle command signal for driving the steering angle is provided in the servo amplifying section, and after the learning section completes learning, the overshoot learning section The reference level set value set based on the learned basic reference level value and the deviation signal are compared in the comparison circuit, and when the deviation signal is within the reference level set value and greater than or equal to the minimum steering angle, the A marine autopilot, characterized in that the rudder is driven by a minimum rudder angle command signal.