JPS5919875B2 - automatic steering system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic steering system that obtains a commanded rudder angle based on a deviation signal corresponding to the deviation between the ship's heading and a set course, and particularly to a weather adjustment system that avoids unnecessary response control during bad weather. Involved.

In conventional automatic steering systems of this type, when the ship's heading deviates even slightly from the set course due to waves or wind in bad weather, a corresponding deviation signal is immediately generated, and this deviation signal is used to control the command rudder. An angle is generated and action is taken to control the rudder.

However, if a commanded rudder angle is generated even with a small deviation signal due to fluctuations caused by waves or wind, the rudder will be steered many times, which is undesirable as it will increase fuel consumption. From this point of view, weather adjustment devices have been provided in the past to prevent the commanded steering angle from occurring due to slight fluctuations in bad weather. That is, as shown in Fig. 1, the difference between the set course signal ψs from the terminal 11 and the heading signal ψi from the terminal 12 is taken by the difference circuit 13, and the deviation signal ψ from this is taken as a dead zone as a weather adjustment device. The signal is supplied to the circuit 14. This dead band circuit 14 does not respond to a deviation signal that is smaller in absolute value than a certain level according to the setting from the terminal 15, and only deviation signals that are larger than a certain level pass through this circuit and are supplied to the arithmetic circuit 16. configured to be used. Necessary calculations are performed in the calculation circuit 16, and this output is supplied as the commanded steering angle δ to the difference circuit IT, where it is compared with the signal δf from the angle transmitter 18 corresponding to the current steering angle δo. The difference is taken. The output of the difference is amplified by the servo amplifier 19, and the power switch 21 is controlled on and off by the output, and the power unit 22 is further controlled by the switch, thereby controlling the steering gear (not shown). controlled. By the way, weather adjustment device 1 in this conventional device
4 is a dead band circuit as mentioned above, and the deviation signal generated by the fluctuations due to weather such as waves and wind is sent to the calculation circuit 16.
Since the rudder angle is no longer supplied to the rudder, the rudder angle command is no longer generated by such fluctuations due to waves or wind.

However, since such small deviation signals are not supplied to the calculation circuit 16, small deviation signals generated when there is a slight difference between the set course and the heading are also blocked and do not reach the calculation circuit 16. Therefore, in such a case, the ship would naturally deviate from the set course, resulting in poor course keeping. Furthermore, as shown in FIG. 2, a conventional weather adjustment device has been proposed in which the output of a difference circuit 13 is supplied to an arithmetic circuit 16 through a low frequency filter 24 as a weather adjustment device.

The frequency of disturbances caused by waves and wind is generally higher than the frequency of the deviation signal for steering. Therefore, high frequency components due to disturbance in the deviation signal are removed by the door transducer 24, and only effective deviation signals are allowed to pass through the door transducer 24. In this case, the low-level effective deviation signal passes through the door wave device 24, so course keeping will not deteriorate, but the cutoff frequency of the door wave device 24 to remove disturbances such as weather is It is necessary to set this value to the optimum value by a signal applied to the terminal 26, and it is necessary to set this value to the optimum value depending on the weather conditions, the loading condition of the ship, etc. It is difficult to make adjustments to achieve this, and it changes depending on various conditions, so
It is difficult to set the optimum cutoff frequency, and this has resulted in drawbacks such as unnecessary steering or relatively high frequency components of the effective deviation signal being cut off, resulting in poor response. From this point of view, the present invention supplies a deviation signal to the first P-wave device that blocks disturbances with components higher than the response frequency specific to the navigation vehicle and the second P-wave device that blocks disturbances with frequency components lower than the response frequency. Compare the output of the Ryoto wave generator,
The level of the commanded rudder angle is controlled according to the output. In other words, when the output level of the second P-wave device is large, it is assumed that the disturbance is large and the commanded rudder angle is attenuated to maintain good course-keeping performance, while special strictness is required in setting the cutoff frequency of the door-wave device. Therefore, an automatic steering device that can realize accurate operation without any trouble can be obtained. FIG. 3 shows an example of an automatic steering system according to the present invention, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In this invention, the deviation signal, that is, the output of the difference circuit 13, is transmitted to the first P-wave device 27 for low-pass and the second P-wave device 2 for high-pass.
8, respectively. The cutoff frequencies of these wavers 27 and 28 are selected to be approximately equal, and the frequency corresponds to the highest component of the speed that the ship follows when the rudder is turned, the fastest speed that the ship can follow with a normal rudder, In other words, it is selected as a response frequency unique to the navigation vehicle. Therefore, for example, as shown in FIG.
The P-wave device 28 has a characteristic such that it passes through FO or more, as shown by a curve 32. Dotted lines 33 and 34 are the wave devices 27, respectively.
, 28. The cutoff frequencies of these door breakers 27 and 28 can be changed by setting signals at terminals 35 and 36, respectively. Outputs ψL, ψ of these door wave devices 27, 28. is supplied to a comparator 37.

Suppose that the output ψL of the first P-wave device 27 is given to the non-inverting input terminal of the comparator 37, and the output ψH of the second P-wave device 27 is given to the inverting terminal, respectively. When ψL≦ψH, the output of the comparator 37 is a saturated positive potential, and when ψL≦ψH, a saturated negative potential is obtained as the output of the comparator 37. The level of the command steering angle is controlled by the output of the comparator 37.

For example, the command steering angle δ from the output of the arithmetic circuit 16 is supplied to the difference circuit 17 through the steering angle adjuster 38, and the coefficient K of the steering angle adjuster 38 is controlled by the output of the comparator 37. The control is such that when the output of the second P-wave device 28 is large and the output of the comparator 37 is negative, the commanded steering angle δ is attenuated by the steering angle adjuster 38. In the steering angle adjuster 38, for example, as shown in FIG. 5, a steering angle command δ from a terminal 39 is supplied to a non-inverting input terminal of an operational amplifier 42 through a resistor 41, and a field effect transistor 43 is connected to both ends of this resistor 41. Its source and drain are connected to each other, and its gate is connected to the output side of the comparator 37 through a diode 44.

A non-inverting input terminal of the operational amplifier 42 is connected to a common potential point through a resistor 45, and an inverting input terminal is connected to the common potential point through a resistor 46 and to an output terminal through a feedback resistor 47. The output ψL of the first P-wave device 27 is
When the output of the comparator 37 is at a positive potential and is larger than the output ψH of the P wave generator 28, the diode 44 is non-conducting, the field effect transistor 43 is conducting, and the command steering angle δ from the terminal 39 is a resistance. The signal is supplied directly to the amplifier 42 without passing through the amplifier 41, that is, without being attenuated.

However, when the output ψH of the second P-wave device becomes larger than ψL, the output of the comparator 37 becomes a negative potential, and the diode 4
4 becomes conductive, transistor 43 becomes non-conductive, and the command steering angle δ reaches the amplifier 42 after being divided by the resistors 41 and 45, that is, attenuated. Now resistors 41, 45,
If the respective resistance values of 46 and 47 are Rl, R2, R3, and R4, the steering angle ratio K is as follows.

Therefore, when the change state of the steering angle ratio K with respect to the frequency is shown in correspondence with FIG. 4, as shown in FIG. Wave device 27
When the output of is zero, K becomes a small value KL. Between these, since the signals supplied to the comparator 37 are both alternating current signals, the signals change from KH to KL depending on their level and phase. The rudder is controlled by this average value, but it is better to make this part as narrow as possible. In this way, the gain K in the steering angle adjuster 38 changes depending on the yawing frequency, and if the gain K is less than f1, the commanded steering angle δ passes with almost no attenuation, and if the yawing frequency is greater than F2. If so, the steering angle command is greatly attenuated, compressed as a small command, and supplied to the difference circuit 17.

The steering angle ratio K is automatically controlled according to the yawing frequency, and in the case of bad weather such as waves or wind, the yawing frequency increases, and the steering angle command is attenuated so as not to respond to such high frequency components. . Therefore, unnecessary steering angles will not be taken. However, when the yawing frequency is low, even if the level of the deviation signal is low, it passes through the rudder angle adjuster 38 without being attenuated, so even if the heading is slightly deviated from the set course, this can be corrected. It has good course keeping properties.

In this case, the cutoff frequencies of the door wavers 27 and 28 are adjusted in advance to a predetermined value depending on the size and shape of the ship, but this is not very strict. In short, the relative ratio between large disturbance components and non-large disturbance components can be set relatively easily, and correct control can be performed in a manner that realizes economical rudder operation in bad weather. It is only necessary to control the gain of the commanded steering angle δ, and therefore, the steering angle gain must be controlled in accordance with the output of the comparator 37 not only in the position of the steering angle adjuster but also in other parts of the steering angle control system using the deviation signal. Bye. Further, in the above description, the deviation signal ψ is supplied to the arithmetic circuit 16 through the first P-wave device 27 of low frequency, but the deviation signal ψ may be directly supplied to the arithmetic circuit 16 without passing through the wave device 2r.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing a conventional automatic steering device, FIG. 3 is a block diagram showing an example of an automatic steering device according to the present invention, and FIG. 4 is a block diagram showing the first P wave device and the second
FIG. 5 is a connection diagram showing an example of the steering angle adjuster 38, and FIG. 6 is a characteristic curve diagram of the steering angle adjuster. 11...Setting course signal input terminal, 12...
... Heading signal input terminal, 13 ... Difference circuit, 16 ... Arithmetic circuit for obtaining command rudder angle, 27 ...
... 1st P wave device, 28 ... 2nd P wave device, 3
7... Comparator, 38... Rudder angle adjuster.

Claims (1)

[Claims] 1. In an automatic steering system that obtains a command rudder angle using a deviation signal corresponding to the deviation between the ship's heading and a set course, the above deviation signal is supplied to prevent disturbances having frequency components higher than the response frequency specific to the vessel. a first filter, a second filter to which the deviation signal is supplied and which blocks signals having components below the response frequency specific to the navigation object, a comparison circuit for comparing the outputs of both filters; An automatic steering system characterized by comprising means for automatically attenuating the commanded steering angle when the frequency of the deviation signal exceeds a response frequency specific to the navigation object based on the output of a comparison circuit.