JPH0154236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to improvements in autopilot systems for small ships.

Various autopilot devices have been developed to automatically maintain a ship's course on a target course.

Among these, autopilot devices mainly for small vessels basically use target course setting signals,
The steering angle is feedback-controlled in accordance with the deviation from the course detection signal so that the deviation is reduced.

Specifically, if the ship's course deviates from the target course due to lateral imbalances in the ship's structure, unbalanced cargo, wind, tidal currents, etc., corrections are made. Since a dead zone is provided, the course is only corrected when the turning angle of the ship deviates from the target course by a predetermined angle or more.

For example, as shown in Figure 1, suppose a situation where the ship deviates from the target course So, like trajectory B,
Each time the ship's turning angle deviates by a predetermined angle from the target course It moves forward with a deviation angle, and the so-called integral offset becomes considerably large.

Therefore, under such circumstances, a problem arises in that the deviation of the ship from the target point becomes large as a result, especially in the case of a long voyage.

As a solution to this problem by minimizing the integral offset, Loran A,
Devices such as Loran-C, Detsuka, Omega, and radio direction finders are already in use, but these were all developed for large and medium-sized ships, and they are not suitable for small ships, both economically and in terms of scale. cannot be practically applied.

The present invention has been made in view of these conventional circumstances, and provides an autopilot device that can reduce integral offset and can be used in small ships economically, in terms of scale, functionality, and performance. The purpose is to obtain.

In order to achieve the above object, the present invention provides an autopilot device that feedback-controls the rudder angle to maintain the ship's course at the target course in response to a servo deviation signal corresponding to the deviation between the ship's target course and the actual ship's course. , a frequency discriminator that selects a long-period fluctuation component from the servo deviation signal, a hold circuit that stores a positive peak value and a negative peak value of the long-period fluctuation component, and adds the positive and negative hold signals. An integral offset correction section is provided, which includes a current steering amount adjustment section that amplifies the current steering amount signal and outputs a correction signal of an integral offset corresponding to the current steering amount. Accordingly, the steering angle was configured to be feedback-controlled.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a block diagram of one embodiment of the present invention.

In the figure, 1 is a subtracter that calculates the difference between the course setting signal D at the voltage level corresponding to the target course and the course detection signal E from the course detection section 2 corresponding to the actual course, and uses this as a subtracter. As the deviation signal ε,
It is output to the weather and steering angle ratio adjustment section 3.

Here, the course detection section 2 is composed of a magnetic compass, a gyro compass, or the like, and outputs a course detection signal E whose voltage level varies in accordance with the course.

In addition, the weather and steering angle ratio adjustment section 3 basically consists of a dead band circuit with a voltage limiting function and an amplifier circuit, and when the deviation signal ε is less than the set voltage, it is cut off and the steering angle ratio is adjusted. , a dead zone is added to stabilize the dead zone.

At this time, under bad weather conditions in which the deviation signal ε fluctuates sharply, instability of the steering angle control can be prevented by increasing this set voltage and widening the dead range.

Furthermore, the amplification factor of the deviation signal can be freely changed, so the rudder angle ratio can be adjusted according to the characteristics of the ship and the cargo situation.

The deviation signal ε that has passed through the adjustment section 3 is sent to the drive section 6 via an adder 4 and a subtracter 5, which will be described later.

The drive unit 6 basically tilts the rudder 7 (rudder angle) in the direction corresponding to the sign of the deviation signal ε (direction that makes the deviation signal ε zero), thereby changing the course. Achieve F.

Here, the tilt angle of the rudder 7 is detected by the rudder angle detector 8, and this rudder angle signal G is subtracted and fed back to the servo deviation signal ε via the subtractor 5 described above.

Therefore, the amount of tilting in the tilting drive of the rudder 7, that is, the amount of steering angle, is secured in accordance with the magnitude of the servo deviation signal ε, and the servo deviation signal ε quickly reaches zero, that is, the ship's The course is set to be pulled back to the target course.

Even in this small feedback circuit consisting of the drive section 6, rudder 7, and steering angle detection section 8, a dead zone is provided in order to stabilize the feedback operation.

That is, when the deviation between the deviation signal ε and the steering angle signal G is less than or equal to the set value, the rudder 7 is not driven to tilt, but maintains its position.

However, this dead width is usually set to a much smaller value than the dead width set by the weather and steering angle ratio adjustment section 3 described above.

In this way, the rudder 7 is feedback-controlled to reduce the deviation between the target course and the actual course, so that the ship's course is more or less stably maintained at the target course. .

By the way, as mentioned before, ships are affected by structural imbalances, cargo imbalances, winds, tidal currents, etc., and their courses are disrupted at various lengths and short periods.

To represent this disturbance virtually, adders 9, 1
0 may be used to supply the long-period disturbance signal H and the short-period disturbance signal J to the course detecting section 2.

The parts described above are basically the same as those of conventional autopilot devices, and the feature of the present invention is that it includes an integral offset correction section 11, which will be described below.

The offset correction unit 11 includes a frequency discrimination unit 12,
It consists of an offset amount storage section 13 and a current steering amount adjustment section 14, and specifically has a circuit configuration as shown in FIG.

Of these, the frequency discriminator 12 is a low-pass filter consisting of a resistor 15, a capacitor 16, an operational amplifier 17, etc., and cuts short-period fluctuation components based on the disturbance signal J from the servo deviation signal ε, thereby eliminating the main cause of integral offset. A long-period fluctuation component based on the disturbance signal H is selected.

The offset amount storage section 13 includes an operational amplifier 18,
19, a positive hold circuit consisting of a diode 20 and a capacitor 21, a negative hold circuit consisting of operational amplifiers 22, 23, a diode 24, and a capacitor 25, and an automatic clear circuit consisting of operational amplifiers 26, 27, a transistor 28, a relay 29, etc. It is composed from.

The positive hold circuit holds (stores) the positive peak value of the long period component of the deviation signal ε in the capacitor 21, and the negative hold circuit holds the negative peak value in the capacitor 25.

These hold signals are signals corresponding to the integral offset amount, and the value is
When the output voltages 8 and 22 reach the upper or lower limit, a relay 29 is opened via a transistor 28 based on the outputs of the comparison operational amplifiers 26 and 27, and is automatically cleared. Further, it can also be cleared by an external signal K.

As a result, even when the ship starts sailing after being stopped for a long time when the servo deviation signal ε is not zero, the hold signal is automatically cleared, so that the offset correction unit 11 can be activated immediately. can be done.

Further, the steering amount adjustment section 14 includes an operational amplifier 30,
This is a summing amplifier consisting of a variable resistor 31, etc., which adds the above-mentioned positive and negative hold signals, amplifies this sum signal, and corrects the integral offset (this steering amount).
Obtain the signal Δδ.

At this time, the amplification factor of the addition signal can be freely adjusted by a variable resistor 31.

In this way, the integral offset correction signal Δδ based on the long-period disturbance obtained by the offset correction section 11 is sent via the adder 4 to the servo control signal Δδ from the weather and steering angle ratio adjustment section 3 to the drive section 6. It is added to the deviation signal ε.

Therefore, in the drive unit 6, the integral offset correction signal Δδ is added to the raw servo deviation signal ε.
In addition, the rudder is tilted and driven, so integral offset can be effectively reduced, and the course can be stably and precisely maintained at the target course, especially against long-period disturbances. Become.

On the other hand, in response to this long-period disturbance, even if the servo deviation signal ε is less than the dead width specified in the weather and steering angle ratio adjustment section 3, the drive is performed in a manner that bypasses this adjustment section 3. In response to the correction signal Δδ sent to section 6, feedback control of the steering angle is performed.

At that time, the substantial dead width is the drive unit 6, rudder 7,
Since this is equal to the small dead width of the feedback circuit consisting of the steering angle detection section 8, feedback control of the steering angle can be started from a point where the deviation signal ε is small compared to the conventional method. In comparison, it becomes possible to maintain the ship's course more accurately on the target course.

Note that the device of the present invention simply adds this integral offset correction section 1 to the conventional autopilot device.
The entire structure can be constructed by simply adding 1, and therefore it is applicable to small ships both economically and in terms of scale.

By the way, if the ship continues sailing by turning the rudder based on a positive hold signal, if the amount of rudder applied is too large or the environment changes (tidal current, wind, etc.), the ship will Gradually begin to turn to the opposite side. As a result, a negative hold signal is generated this time, and the ship attempts to steer in the opposite direction.

At this time, the positive and negative hold signals are added together in the current steering amount adjustment section 14, and the value of the positive hold signal is subtracted, so that the effect of quickly performing the current steering in the opposite direction is obtained.

Next, the operating characteristics of the device of the present invention will be described with reference to the qualitative explanatory diagrams of FIGS. 4 and 5.

If no feedback control of the steering angle is performed, the servo deviation signal ε is as shown in FIG. 4R.
Let us assume a case where a long-period disturbance is applied to the ship, which gradually increases and causes the course to gradually deviate from the target course X, as shown in Figure 5 R'.

When the conventional autopilot device is operated, as shown in FIG. 4S, when the deviation signal ε exceeds the dead zone Y, feedback control of the steering angle is performed, and the deviation signal ε returns to zero.

However, from that point on, the deviation signal ε increases again with the same slope as the previous time, and when it exceeds the dead zone Y, the steering angle control is performed again.

Such operations are repeated, and as a result, the course as a whole deviates from the target course X by a certain angle of deviation while gently meandering as shown in FIG. 5S'.

On the other hand, when the autopilot device of the present invention is operated, the dead zone becomes narrower for long-period deviations as described above, so that the deviation signal ε becomes smaller than the conventional dead zone Y, as shown in FIG. As soon as the small dead zone Y' is exceeded, feedback control of the steering angle is performed and the deviation signal ε is pulled back to zero.

From this point on, the deviation signal ε increases again, but since the rudder is always tilted by the amount of correction of the integral offset (corresponding to the value of the correction signal Δδ that stores the amount of offset), the slope of the increase is It will be smaller than the previous one. Then, in the next steering angle control, the integral offset is almost completely corrected, and thereafter the deviation signal ε is maintained at almost zero.

After that, the amount of steering angle that almost completely corrects the integral offset is constantly maintained.

As a result, as shown by T' in FIG. 5, the course is maintained substantially coincident with the target course X, and the final deviation width of the course is significantly reduced compared to conventional autopilot devices.

As explained above, in the present invention, the integral offset correction section stores the long-period fluctuation component of the servo deviation signal to obtain the offset correction signal, and adds this correction signal to the servo deviation signal to adjust the steering angle. Since the feedback control is performed, the integral offset can be effectively reduced, and the ship's course can be accurately maintained at the target course, especially against long-period disturbances.

Furthermore, since the entire system can be configured by simply adding this integral offset correction section to a conventional autopilot system, it can be applied to small ships both in terms of scale and economy.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing how the course is controlled by a conventional autopilot device;
The figure is a block diagram showing the device of the present invention, FIG. 3 is a circuit diagram specifically showing the integral offset correction section in FIG. 2, and FIGS. FIG. 3 is an explanatory diagram showing the operating characteristics of the device. DESCRIPTION OF SYMBOLS 1... Subtractor, 2... Course detection part, 3... Weather and steering angle ratio adjustment part, 4... Adder, 5... Subtractor, 6... Drive part, 7... Rudder, 8... Rudder angle detection part, 9, 10 ...Adder, 11... Integral offset correction section, 12... Frequency discrimination section, 13... Offset amount storage section, 14... Current steering amount adjustment section.

Claims (1)

[Claims] 1 In an autopilot device that feedback-controls the rudder angle to maintain the ship's course at the target course in response to a servo deviation signal corresponding to the deviation between the ship's target course and the actual course, long-period fluctuation components are detected from the servo deviation signal. a frequency discriminator for selecting a frequency discriminator, a hold circuit for storing the positive peak value and a negative peak value of the long-period fluctuation component, and amplifying a signal obtained by adding the positive and negative hold signals to obtain the current steering amount. An integral offset correction section is provided, which includes a steering amount adjustment section that outputs a corresponding integral offset correction signal, and the steering angle is feedback-controlled in accordance with the addition signal of the correction signal and the servo deviation signal. An autopilot device configured as follows.