JPS6135038B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in marine automatic steering systems.

Conventionally, in order to determine the position of the rudder, the rudder is driven by a drive means according to the deviation between a steering command value and an electric signal representing the rudder position so that this deviation becomes zero. The driving means includes a solenoid valve and a hydraulic cylinder operated by the solenoid valve, and is configured such that the rudder is angularly displaced by the hydraulic cylinder.

A block diagram of a conventional steering device is shown in FIG.
1 is a subtraction circuit that subtracts the steering command value and the feedback signal; 2 is a first level discrimination circuit that discriminates the level of the output of 1; 3 is a driving means including a solenoid valve, a hydraulic cylinder, and a steering device; 4 is a A potentiometer is shown that detects the helm position and generates a feedback signal. In this device, when the steering angle deviation signal which is the output of the subtraction circuit 1 exceeds the dead zone of the first level discrimination circuit 2, the rudder is moved in a direction to reduce the steering angle deviation, and the steering angle deviation signal is transmitted to the first level discrimination circuit 2. The rudder will stop when it falls below the dead zone 2. In this device, on/off control is performed by the first level discrimination circuit 3, so the steering command value is automatically determined from the course deviation signal, which is the difference between the ship's set course and the actual course, as an input signal to this device. When using the output signal of the automatic steering system determined as follows, the steering command value changes continuously, the first level discrimination circuit 2 repeatedly turns on and off, and the solenoid valve 3 becomes overworked. The number of times the first level discrimination circuit 2 repeats on/off is greater when the steering command value changes slowly than when the steering command value changes rapidly, and has the property of overworking the electromagnetic valve.

A typical prior art autopilot system diagram for reducing the number of maneuvers is shown in FIG. The weather adjustment circuit 60 for reducing the number of times of steering is such that when the hull undergoes yawing due to external factors such as waves, the azimuth deviation signal fluctuates and the rudder angle command changes frequently, making it difficult to perform steering. It is intended to prevent The weather adjustment circuit 60 is, for example,
In 6701, it was used as a dead band circuit, and also
Then, as a filter circuit,
-30917 is known as the automatic limit level setting mechanism. Tokuko Sho 47-6701 and Tokuko Sho 47-9146
In this example, the characteristics of the weather adjustment circuit 60 are automatically set according to the steering frequency. Tokuko Showa 50-30917
In this method, the characteristics of the weather adjustment circuit are automatically changed according to the frequency of fluctuations in azimuth deviation. The steering angle command value from the weather adjustment circuit and the actual steering angle from the detector 61 are subtracted by a subtractor 62 to obtain a steering angle deviation. This steering angle deviation is amplified in an amplifier circuit 63 and applied to a circuit 64 including a solenoid valve and a relay, and a power unit 65 changes the steering angle. This changes the orientation of the ship 66. The azimuth deviation is given to a proportional-integral control circuit 67. Such prior art attempts to reduce the number of steering operations by not giving a rudder angle command value when the hull yaws frequently, and the rudder angle control system always forms a loop. There is. The steering angle control system includes components for on/off control such as electromagnetic valves and relays, as shown by reference numeral 64.

If the azimuth deviation causes low frequency fluctuations due to low frequency undulations, the steering angle command value causes low frequency fluctuations as shown in FIG. 81. At this time, when trying to make the steering angle follow the command value by on/off control, the difference between the steering angle command value and the actual steering angle shown in FIG. 82, that is, the steering angle deviation shown in FIG. occurs, and when this steering angle deviation occurs slightly, steering will be carried out, and the solenoid valve or relay will be repeatedly turned on and off as shown in Fig. 8, 4, and therefore the steering and stopping will be Frequently repeated, the solenoid valve or relay will be overworked.

Another prior art is, for example, Japanese Unexamined Patent Publication No. 49-26992, the structure of which is shown in FIG. In this marine automatic steering system, an azimuth deviation signal, which is the difference between the azimuth command signal and the azimuth detector 80, is given to an autopilot 81 to derive a steering angle command signal. The steering angle deviation, which is the difference between this steering angle command signal and the actual steering angle detected by the steering angle detector 82, is given to a relay element 83, and the power unit 84 is activated by the output of this relay element 83. When activated, the actual steering angle can be obtained. The actual orientation of the hull 85 is detected by the orientation detector 80. The characteristics of the relay element 83 are such that instead of using a small hysteresis width as shown in FIG. 12, the hysteresis width is widened as shown in FIG. 13, thereby further reducing the number of steering operations. There is.

In general, the dead band width of the relay element 83 is about 0.1 degrees in an actual ship usage environment, and is set to about 0.3 degrees at most. This is because the width of the dead zone determines the positioning accuracy of the steering angle, and it is not normally done to make it larger than this. Therefore, in this prior art, the effect of reducing the number of steering operations is large for a change in the steering angle command value of about 0.1 to 0.3 degrees, and it may be difficult to obtain the reduction effect depending on the fluctuation of the steering angle command value.

FIG. 14 shows the response characteristics in the prior art shown in FIG. 11 above. In this Figure 14,
As the steering angle command value like lines l8 to l10,
When inputting a lamp signal, lines l8a to l1
The actual steering angle movement is shown as 0a. In the prior art, steering is performed when the difference between the commanded steering angle and the actual steering angle, that is, the magnitude of the steering angle deviation, exceeds the dead band width.
In such prior art, as described above, when the steering angle command value changes quickly and the steering angle deviation frequently changes greatly, there is a problem that the steering becomes frequent.

The purpose of the present invention is to prevent the rudder from being driven for a long time when the rudder angle deviation is small and have little effect on the ship's course, and to quickly respond when the rudder angle deviation is large and have a large effect on the ship's course to reduce the course error. To provide a circuit for reducing the number of steering operations, which reduces wasteful steering by not increasing the number of steering wheels, thereby improving the life of a rudder drive means including a solenoid valve, and suppressing the occurrence of failure. That's true.

FIG. 2 is a block diagram of a steering system according to the invention. Parts corresponding to those in FIG. 1 are given the same reference numerals. 5 is a relay or semiconductor switching circuit, 6 is an integrating circuit, 7 is a second level discrimination circuit, and 8 is a holding circuit. The function of the holding circuit 8 is
The output signal of the second level discrimination circuit 7 connects the switching circuit 5 to the deviation signal side and resets the integration circuit 6.
The steering angle deviation signal and the grounding signal calculated by the subtracting circuit 1 are inputted to the switching circuit 5, and the steering angle deviation signal and the grounding signal are switched according to the output signal of the holding circuit 8, and the rudder is in a movable state and a stopped state. control. When the ground signal is connected, the steering angle deviation signal is integrated, and when the absolute value of the integration result exceeds the second discrimination level, a signal is output from the second level discrimination circuit 7 and is passed through the holding circuit 8 to the switching circuit 5. and connect the steering angle deviation signal to perform steering. When the rudder starts to move, the holding circuit 8 is activated and the switching circuit 5 maintains the connection of the rudder angle deviation signal, and when the rudder angle signal becomes below the discrimination level of the first level discrimination circuit 2 and the rudder stops, the switching circuit 5 operates. Switch circuit 5 and connect the ground signal. Further, while the rudder is moving, the integrating circuit 6 is reset by the output signal of the holding circuit 8, and when the rudder stops, the integrating circuit 6 starts integrating.

FIG. 3 is an electrical circuit diagram of one embodiment of the present invention. The rudder 45 of the ship is driven by the drive means 3. This driving means 3 includes lines 37a and 37b.
responds to input signals applied to it. A steering command signal from the marine automatic steering system 9 is given to the subtraction circuit 1. This marine automatic steering system 9 derives a signal having a level corresponding to the difference between the set course of the ship and the actual course. The subtraction circuit 1 is supplied with a signal from a potentiometer 4 associated with a piston rod 43 of a double-acting cylinder 42 which drives a rudder 45 in angular displacement about a rudder axle 44 . The deviation thus derived from the subtraction circuit 1 to the line 10 is an electrical signal obtained by subtracting the value representing the rudder position from the steering command value.

Deviation from line 10 is determined by switching circuit 5
is applied to the first level discriminator circuit 2 via a line 29. The switching circuit 5 is connected to the line 25
When the signal applied to the line 10 is at a high level, the common contact 26 is made conductive to the individual contact 27 to provide the deviation from the line 10 to the first level discrimination circuit 2. Further, when the line 25 is at a low level, this switching circuit 5 conducts the common contact 26 to the individual contact 28 to keep the input of the first level discrimination circuit 2 at a low level, so that the deviation is transmitted to the first level discrimination circuit 2. Block out what is given. This makes it possible to control the state in which the rudder 45 follows the rudder angle command value and the state in which the rudder 45 is forcibly stopped.

Deviations from the line 10 are applied to the integrator circuit 6 via a resistor 11 with a large resistance value, so that the common contact 26 of the aforementioned switching circuit is connected to the individual contact 2.
When connected to 8, the deviation is integrated. The integrating circuit 6 includes an operational amplifier 12, an integrating capacitor 13, and a switching transistor 14 that discharges and resets the integrating capacitor 13.
and a resistor 48 having a small resistance value. Due to the conduction of the transistor 14, the capacitor 12
is instantly discharged. Integral operation is possible when transistor 14 is cut off.

The output from the integrating circuit 6 is given to a second level discrimination circuit 7. The signal from line 52, from which the integrated output from integrating circuit 6 is derived, is passed to comparator 19,
20 is received at one input. This comparator 1
9 and 20 have discrimination levels E3 and E4 determined by voltage dividing resistors 15 to 18, respectively. Comparator 19 derives a high level signal when the integral output from line 52 exceeds discrimination level E3, and vice versa, derives a low level signal. Comparator 20 derives a low level signal when the integral output from line 52 exceeds discrimination level E4, and vice versa, a high level signal. In this manner, the second level discrimination circuit 7 determines whether the integral output is within the second range defined by the discrimination levels E3 and E4. Comparator 1
The outputs from 9 and 20 are applied to the set input S of the flip-flop 23 of the holding circuit 8 via the OR gate 21, and the set output Q of the flip-flop
controls the level of line 25. When the line 25 becomes high level, a deviation signal is applied to the first level discrimination circuit 2 via the switching circuit 5.

The first level discrimination circuit 2 includes a switching circuit 5
a comparator 34, 35 receiving on one respective input the deviation from line 29 via a common contact 26 of the comparators 34, 35, and voltage dividing resistors 30-- connected in connection with the other respective inputs of these comparators 34, 35. 33. Voltage dividing resistors 30 to 33 determine discrimination levels E1 and E2 of comparators 34 and 35, respectively.

The comparator 34 derives a high level output when the deviation via the switching circuit 5 exceeds the discrimination level E1 determined by the voltage dividing resistors 30 and 31, and conversely outputs a low level signal when the deviation is low. Derive. The comparator 35 has a deviation from the voltage dividing resistors 32 and 3.
3, a low level signal is derived, and vice versa, a high level signal is derived. The first range defined by the discrimination levels E1 and E2 is
Determines the level of deviation at which the drive means 3 does not drive the rudder 45. The outputs of comparators 34 and 35 are on line 37
a, 37b to the driving means 3, and also OR
The signal is applied to the inverting circuit 22 via the gate 36. The output signal of the inversion circuit 22 is applied to one terminal of an AND gate 24. Further, the output signal of the OR gate 36 is applied to a delay circuit 53 consisting of a resistor 49 and a capacitor 50, and a delayed signal from the delay circuit 53 is applied to the other terminal of the AND gate 24.
The output signal of AND gate 24 is applied to reset input R of flip-flop 23. As a result, when the output signal of the OR gate 36 changes from high level to low level, the flip-flop 23
will be reset. In addition, flip-flop 2
The set output Q of 3 is applied to the transistor 14 of the integrating circuit 6, and is also applied to the switching circuit 5 from the line 25. As a result, the deviation signal exceeds the level of the first level discrimination circuit 2, and the rudder 4
When the circuit 5 is being driven, that state is maintained and the integrating circuit 6 is reset. Furthermore, when the deviation signal becomes below the level of the first level discrimination circuit 2 and the rudder 45 stops, the common contact 26 of the switching circuit 5 is connected to the individual contact 28, and the integrating circuit 6 is caused to start integration.

In the driving means 3, the outputs from the lines 37a and 37b are amplified by amplifier circuits 38 and 39, respectively, and when there is a signal in either of the amplifier circuits 38 or 39, the solenoid valve 40 is moved to the valve position 40a or 40b.
When there is no signal in the amplifier circuits 38 and 39, the center position 40c is taken. Pressure oil from a hydraulic source 41 is applied to a double-acting cylinder 42 from a solenoid valve 40 . The piston rod 43 of the double-acting cylinder 42 drives the rudder 45 via the rudder handle, and the rudder 45
is angularly displaced around the rudder shaft 44 according to the displacement of the piston rod 43.

The operation of the circuit will be explained with reference to FIG. The steering command value from the marine automatic steering system 9 is shown in FIG.
The signal derived to zero is shown in FIG. Now, assume that the common contact 26 of the switching circuit 5 is electrically connected to the individual contact 28. The integrating circuit 6 integrates the deviation from the line 10 from time t0. The integral output from line 52 increases over time as shown in FIG. 42. The integral output on line 52 reaches the discrimination level E3 at comparator 19 of second level discrimination circuit 7 at time t1, where comparator 19 derives a high level signal which is applied to set input S of flip-flop 23. , the line 25 becomes high level as shown in FIG. 4, and the common contact 26 of the switching circuit 5 becomes conductive to the individual contact 27.

Note that the time required for the integral output to reach the discrimination level E3 in the comparator 19 of the second level discrimination circuit 7 changes depending on the deviation signal on the line 10. That is, when the level of the deviation signal is low, the integration time is long, and when the level of the deviation signal is high, the integration time is short. As shown in FIG. 4, a deviation from line 10 is given to line 29 after time t1 when line 25 becomes high level. If this deviation exceeds the discrimination level E1 of the comparator 34 in the first level discrimination circuit 2 as shown in FIG.
A high-level signal is derived and amplified by the amplifier circuit 38, and the electromagnetic valve 40 becomes the valve position 40a, and the rudder 45 is angularly displaced. In this way, the rudder 45 operates at time t1.
~t2, the angular displacement continues as shown in FIG. 4. Therefore, the output from the potentiometer 4 changes, so that the deviation in the line 10 decreases from time t1 to t2 as shown in FIG. 4. During this period from time t1 to t2, the set output Q of the flip-flop 23 is
Common contact 26 of switching circuit 5 is connected to individual contact 2
7 remains conductive, and the transistor 14 of the integrating circuit 6 is made conductive, and the capacitor 1
3 is discharged, and the integrating circuit 6 is kept in a reset state. At time t2, when the output from the first level discrimination circuit 2 changes from high level to low level, flip-flop 23 is reset. Therefore, the common contact 26 of the switching circuit 5 becomes conductive to the individual contact 28, and the transistor 14 remains cut off. In this way, from time t2 onwards, the integrating circuit 6 is brought into an active state.

If the signal from the marine automatic steering system 9 is negative and therefore the output from the integrating circuit 6 increases in the negative direction, the integral from line 15 is calculated at the discrimination level E4 instead of the discrimination level E3. The output is level discriminated.

In this way, when the steering command value changes rapidly, tracking is performed with little delay, and when the steering command value changes slowly, it is possible to reduce the number of times the steering is performed without performing steering for a long time. Since the integration circuit 6 evaluates the degree of error in the course due to no steering, it is possible to reduce unnecessary steering that is not necessary for course maintenance.

Further, when the steering command value ranging from positive to negative is derived from the marine automatic steering system 9 in a short cycle with a small amplitude as shown in FIG. 5, the integrated output from the line 52 of the integrating circuit 6 is 2, the discrimination level is within the range of E3 to E4, and the outputs from the comparators 19 and 20 remain at low level. Therefore, the common contact 2 of the switching circuit 5
6 is disconnected from the individual contact 27 and is electrically connected to the individual contact 28. In this way, the drive means 3 is not activated unnecessarily.

FIG. 6 is a system diagram of a driving means according to another embodiment of the present invention. In this drive means, the double-acting cylinder 4
The output from 2 controls the tilt angle of the pump 46 whose discharge amount can be adjusted. As a result, the discharge amount from the pump 46 is changed by the double-acting cylinder 47.
Pressure oil from pump 46 actuates double-acting cylinder 47, which causes angular displacement of rudder 45. The displacement of the double-acting cylinder 47 works to reduce the tilting angle of the pump 46 by the link mechanism. Such a drive means with a variable displacement pump 46 can also be used in the present invention.

As described above, according to the present invention, the deviation is integrated by the integrating circuit, and the integrated output is the predetermined second
When the deviation exceeds the range of , the deviation is given to the first level discrimination circuit, and the driving means is activated only when the deviation exceeds a predetermined first range of the first level discrimination circuit. Therefore, the drive means does not drive or stop the rudder unnecessarily frequently.
As a result, the life of the driving means is increased, the occurrence of failures is suppressed, and maintenance becomes easier.

The present invention is not intended for weather adjustment of an autopilot as described in connection with the prior art described above, but in the present invention, as shown in FIG. By inserting the circuit 71 and cutting the steering angle control loop, the steering angle deviation while the steering is stopped is integrated by the integrator 72, and the integral value is a constant value determined by the level discrimination circuit 73. When the value exceeds the value, the steering angle control is performed, and when the steering angle command value and the actual steering angle match, the steering angle control system is turned off again, the steering is stopped, and the integrator 72
Reset and start integration again. The output from the switching circuit 71 is applied to a circuit 74, such as a solenoid valve or a relay, and a power unit 75 is activated to drive the rudder. Therefore, in the present invention, the number of steering operations is reduced by cutting the steering angle control loop, and when a large steering angle deviation occurs, the steering angle control loop is formed in a short period of time, and a small steering angle deviation occurs. Sometimes, the steering angle control is not performed until a long period of time has elapsed. This reduces the number of steering operations and prevents the solenoid valve from being overworked. An azimuth deviation is determined based on the azimuth of the ship 76 and the set azimuth, and this azimuth deviation is given to the autopilot 77 to derive a rudder angle command value and given to the rudder angle control system.

According to the basic configuration of the present invention shown in FIG. 9, the steering angle deviation shown in FIG. 10 is integrated, and the integrated result of the steering angle deviation is displayed in FIG. Steering is performed only when the absolute value of the value is accumulated above a certain value. FIG. 10 shows the steering angle command value and the actual steering angle. Therefore, when the steering angle deviation is small, the steering is stopped for a long time, and when the steering angle deviation is large, the steering is started in a short time. Therefore, if the effect on the ship's course is small, i.e., the rudder angle deviation is small, the steering is stopped for a long time and the number of times the steering is reduced, and if the ship's course is greatly affected, i.e., the rudder angle deviation is large. A feature of the present invention is that the time required to stop the steering is short. That is, according to the present invention, it is possible to reduce steering operations that are not important in maintaining the heading of the ship. In this manner, the drive is performed as described above, and the rudder is not stopped unnecessarily frequently, thus increasing the life of the drive means, reducing the occurrence of breakdowns, and facilitating maintenance.

In the present invention, while the steering angle deviation signal is cut off by the switching relay 71 as shown in FIG.
The integrator 72 continues to integrate the steering angle deviation signal. When the integral value of the integrator 72 exceeds the value set by the comparator 73, the switching relay 71 is operated to input the steering angle deviation signal to the relay element 74 to perform steering, and the steering angle deviation signal is transmitted to the relay element 74. When it returns below the dead band width of element 74, integrator 72 is reset. Therefore, the switching relay 71 cuts off the steering angle deviation signal, and the integrator 72 starts integrating again.

Therefore, according to the present invention, the azimuth angle of about 5 to 10 degrees that occurs during automatic navigation, including minute changes in the rudder angle command of less than about 0.3 degrees, as described in connection with the prior art described above. It is also possible to reduce the number of times of steering for yawing, and even when the steering angle command value changes by, for example, about 5 to 10 degrees during yawing, the effect of reducing the number of times of steering can be achieved.

In the present invention, as shown in FIG. 15, the steering is started when the integral values S1, S2, and S3 of the steering angle deviation exceed predetermined values. When the command value of the rudder angle moves quickly, the actual rudder angle responds in a short time as shown by lines l12a and l13a, and when the command value of the command rudder angle moves slowly as shown by lines l12 and line l13. In this way, it takes a long time to respond to the actual steering angle, thereby reducing the number of steering operations. Such an effect cannot be achieved by the above-mentioned prior art, and is a unique effect of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional steering device, FIG. 2 is a block diagram of a steering device according to the present invention, FIG. 3 is an overall electrical circuit diagram of an embodiment of the present invention, and FIGS. 4 and 5 are A waveform diagram to explain its operation,
FIG. 6 is a system diagram of a driving means implemented in conjunction with the present invention, FIG. 7 is a system diagram of a typical prior art, and FIG. 8 explains the operation of the prior art shown in FIG. FIG. 9 is a system diagram showing the basic configuration of the present invention. FIG. 10 is a waveform diagram explaining the operation of the system diagram shown in FIG. 12 and 13 are diagrams showing the characteristics of the relay element 83 of the prior art shown in FIG. 11, FIG. 14 is a diagram showing the characteristics of the prior art shown in FIG. 11, and FIG. FIG. 3 is a diagram showing characteristics of an embodiment of the invention. 1... Subtraction circuit, 2... First level discrimination circuit,
3... Drive means, 4... Potentiometer, 5...
... Switching circuit, 6 ... Integrating circuit, 7 ... Second level discrimination circuit, 8 ... Holding circuit, 9 ... Marine automatic steering device, 21, 36 ... OR gate, 22
...Inverting circuit, 23...Flip-flop, 24
...AND gate, 40 ... solenoid valve, 42 ... double-acting cylinder, 45 ... rudder.

Claims (1)

[Claims] 1. A first level discrimination circuit that discriminates whether or not the deviation between the steering command position from the marine automatic steering system and the rudder position is within a predetermined first range;
further applying the output of the first level discrimination circuit to the drive means, thereby disabling the drive means when the deviation is within a first range and activating the drive means when the deviation exceeds the first range; In a control circuit of a marine steering device that drives a rudder, a switching circuit is provided that can switch between a deviation signal and a ground signal according to a signal given from another source and provide the signal to the first level discrimination circuit, and a switching circuit that integrates the deviation; It is equipped with an integrating circuit whose integral output can be reset to zero, and a second level discrimination circuit that discriminates the level of whether the output from the integrating circuit is within a predetermined second range, and the switching circuit is configured to output a ground signal. When the rudder is forced to stop by connecting the integrator, the integrator integrates the deviation signal, and if the integration result output exceeds the range of the second level discrimination circuit, the switching circuit connects the deviation signal and activates the switching circuit. If the deviation exceeds the range of the first level discrimination circuit and the rudder is driven, the integrating circuit is reset and the switching circuit keeps the deviation signal connected, the rudder is driven and the deviation is detected by the first level discrimination circuit. 1. A steering frequency reduction circuit for a marine automatic steering system, characterized in that a switching circuit connects a ground signal and an integrator integrates a deviation signal when the switching circuit enters a range of .