JPS6234597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic navigation system that automatically navigates a ship in the direction of a preset destination position.

As this type of device, for example, an automatic steering device using a magnetic compass has been conventionally used. That is, the heading direction of the own ship is detected using a magnetic compass, the detected direction is compared with a preset set direction, and the rudder is controlled so that the set direction matches the detected direction.

However, the actual course of the ship does not necessarily match the heading direction. For example, in Figure 1,
Set the bow direction θ ₁ toward the destination P ₀ and set the bow direction θ ₁
When the velocity in the direction is V ₁ and a tidal current with a velocity V ₂ acts in the θ ₂ direction, the ship actually sails in the θ ₃ direction at a velocity V ₃ . Therefore, if things continue as they are, the ship will be sailing in a direction different from the destination, so the ship must constantly check its own position and adjust its bow direction while navigating. This cannot be said to be automatic navigation.

Therefore, after the applicant first set the destination position in the earlier application, Patent Application No. 52550 of 1982 (Japanese Patent Application Laid-open No. 166611/1982), the actual route direction differed from the destination direction due to external factors. At that time, we proposed an automatic navigation system that automatically corrects the heading of a ship and sets a course toward its destination.

This invention is an improvement on the problems of the prior invention, and will be explained in sequence below.

First, the prior application will be explained with reference to FIG. 1 is a course setting device for setting the destination position; 2 is a direction detector for detecting the heading direction of the ship; for example, a magnetic compass is used.

The set course of the course setter 1 and the detected direction of the direction detector 2 are compared in a comparator circuit 3. The comparison circuit 3 detects how much the ship's heading deviates from the set heading. Note that the course setter 1, the azimuth detector 2, and the comparison circuit 3 constitute a azimuth difference signal generator 4. The orientation difference signal is applied to a control circuit 6 via an adder circuit 5. The control circuit 6 controls the rudder angle of the rudder 7 to match the detected heading with the set course, and sends a control output to the drive unit 8 that drives the rudder 7. Reference numeral 9 denotes a rudder angle detector which sends the detected rudder angle output to the control circuit 6 to prevent the hunting phenomenon of rudder angle control and to perform smooth rudder angle control.

The adding circuit 5 is supplied with a voltage corresponding to the course deviation from the course deviation amount calculation circuit 10 .

The course deviation calculation circuit 10 receives navigation signals from different transmitting stations, such as a Loran receiver, measures the time difference or phase difference between the received navigation signals of each station, and uses this time difference etc. The length of the perpendicular line drawn perpendicularly from the own ship's position to the navigation device that knows the own ship's position on the Loran map, and the linear route set up connecting the ship's departure position and destination position on the Loran chart. By measuring this, the amount of deviation from the ship's set course is calculated. By adding this amount of deviation to the heading difference signal in the adding circuit 5, the rudder is controlled so that the own ship's heading matches the set course (the normal operation of an autopilot), but instead of The bow is directed in a direction that is shifted by a certain amount in a direction closer to the set course than the course. This opening is explained using electrical signals as shown in FIG. That is, when the horizontal axis represents the azimuth error and the vertical axis represents the steering voltage, the output of the azimuth difference signal generator 4 is shown as a solid line. As can be understood from this, the steering voltage changes proportionally from +E ₁ to -E ₂ during the azimuth difference between +L ₁ and -L ₂ , but
It exhibits a characteristic of saturation for orientation differences greater than that.

For example, when the heading of the boat moves to the right with respect to the set heading, a positive voltage is generated, which controls the control circuit 6 and the drive unit 8 to move the rudder to the port side, causing the bow to turn to the left. Conversely, if the bow is to the left with respect to the set heading, a negative voltage will be generated, causing the bow to turn to the right. However, in either case, if the bow of the ship matches the set heading, the voltage becomes zero and the rudder is maintained in a straight line. If the ship is drifted while maintaining a predetermined heading due to the influence of tidal currents, etc., it will deviate from the course, but the heading will remain in line with the set heading and no voltage will be generated. Therefore, in order to return to the original course, the set heading must be corrected. However, now the addition circuit 5
If _a voltage Ex ₌ E ₀ corresponding to the amount of deviation from the course is added from _the outside to A steering signal is generated to cause the bow to turn to port. As a result, the course is controlled to approach the set course. This is the effect of the prior invention.

However, the following problem may occur. A case can be considered in which the ship is artificially deviated from the course to avoid some kind of obstacle on the initially set course, and then the device is driven to return it to the course.

In this case, since the amount of deviation from the own ship's course is quite large, the deviation amount voltage Ex may become a positive voltage larger than the maximum value E ₂ of the azimuth difference voltage, as shown by the dotted line P ₂ . Then, since a positive voltage is always supplied to the control circuit 6, the rudder turns significantly to the left and an abnormal state occurs in which the ship continues to turn to the left until the controllable region is reached.

The present invention eliminates this drawback and aims to suppress the route deviation amount signal from exceeding the maximum value of the azimuth difference signal. This will be explained below with reference to FIG. 4, but blocks with the same reference numerals as in FIG. 2 have the same functions, and their explanation will be omitted.

The output of the azimuth difference signal generator 4 is supplied to the summing circuit 5 via the resistor R ₁ while the phase inversion amplifier A ₁
Through the diode D ₁ and D ₃ through the capacitor
Charged to C ₁ and C ₂ . This maintains the maximum value of the orientation difference signal (E ₁ and -E ₂ in FIG. 3).
The outputs of capacitors C ₁ and C ₂ are amplifiers with amplification degree of 1.
They are connected to diodes D ₂ and D ₄ via A ₂ and A ₃ , respectively. A voltage from the course deviation calculation circuit 10 is applied to the other ends of the diodes D ₂ and D ₄ via a resistor R ₃ and is output to the adding circuit 5 via a resistor R ₂ . Here, the value of R ₂ is made equal to the value of R ₁ .

In the above circuit, if the circuit operates with the own ship deviating from the set course by a wide range, if the voltage from the deviation calculation circuit 10 attempts to exceed the voltage held in the capacitors C ₁ and C ₂ , the diode D ₂ or D ₄ is conductive and limited. Note that the voltage held in the capacitors C ₁ and C ₂ is set slightly lower than the output voltage of the azimuth difference signal generator 4 by making the amplification degree of A ₁ less than 1. Therefore, the ship does not rotate while the rudder is held in one direction.

Note that when the course is stable, the voltages of C ₁ and C ₂ are both zero, but in reality, some voltage is maintained due to the rocking of the ship, so there is no problem with control using external signals.

As explained above, according to the present invention, the backup operation is always performed using an external signal within the range of the azimuth difference signal, so even if the own ship deviates significantly from the course, the ship does not turn and remains on the set course. automatically returns to.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of route deviation, Fig. 2 is a block diagram showing an embodiment of the prior application, Fig. 3 is a characteristic curve diagram showing its electrical characteristics, and Fig. 4 is a block diagram showing an embodiment of the present invention. It is a diagram.

Claims (1)

[Claims] 1. A direction setting device for setting the destination position of own ship;
an azimuth detector for detecting the heading of the own ship; a azimuth difference signal generator for obtaining a azimuth difference signal from the output of the azimuth setting device and the output of the azimuth detector; A control device that matches the azimuth with the azimuth set by the azimuth setting device; and a control device that receives navigation signals from different transmitting stations and measures the time difference or phase difference between the received navigation signals of each station; Alternatively, a navigation device that knows the own ship's position on the map using phase difference, and measurement by the navigation device on the set route of the own ship, which is set based on the ship's departure position and destination position on the map. a calculation means for calculating the amount of deviation of the current position on the map, and equivalently slightly changing the set orientation of the azimuth setting device based on the amount of deviation calculated by the calculation means to reduce the amount of deviation. and means for suppressing the deviation amount representative signal so that the signal representing the deviation amount does not exceed the maximum value of the azimuth difference signal.