JPS6147441B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a directional antenna mounted on a mobile object,
Especially regarding directional control devices for directional transmitting antennas,
In particular, the transmitting antenna is automatically directed toward the base station at all times, and the current location of the mobile object can also be detected.

Generally, when broadcasting television from a mobile body such as a ship, it is necessary to always point a directional transmitting antenna mounted on the mobile body in the direction of a base station. In addition, especially when reporting on distress incidents etc. late at night or under environmental conditions such as dense fog,
In order to arrive at a distress site safely and quickly, it is necessary to fully grasp the current position of a mobile object and the direction in which it should proceed.

Conventionally, methods for detecting the current position of a moving object include (1) methods using artificial satellites, especially navigation satellites, radars, radio navigation devices, such as so-called LORAN, (2) methods using three or more fixed radio wave sources, For example, there are methods to detect the direction of arrival of broadcast waves from radio, television, etc., but method (1) requires large and complicated equipment, lacks maneuverability, and requires the use of small fishing boats, etc. It is not appropriate for maritime emergency reporting, and (2) is
At sea or on land where there are many obstacles, errors due to radio wave diffraction are large, and disadvantages include the need to install a rotatable directional receiving antenna separately from the main relay antenna system to detect the direction of arrival of the radio waves. It was hot.

In addition, methods for controlling the pointing direction of a transmitting antenna on a mobile object include (3) a method in which a base station specifically transmits a radio wave other than that for relaying, and the arrival direction of the radio wave is detected on the mobile object; (4) As described in Japanese Utility Model Publication No. 1972-22411, which is filed by the applicant, geomagnetism is used as a common reference direction, and the deviation angle of the receiving antenna direction of the base station, that is, the direction of arrival of radio waves, from magnetic north is determined. There are methods such as transmitting to a mobile object and adjusting the deviation angle from the magnetic south of the transmitting antenna on the mobile object, but all of these methods involve transmitting radio waves different from those for relay from the base station to the mobile object. The drawback was that it needed to be sent all the time.

Moreover, all of the conventional methods described above have the disadvantage that they cannot simultaneously satisfy the various requirements described above.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, automatically detect the current position of a moving object with a relatively simple configuration, and connect the antenna mounted on the moving object to a fixed base station at all times. An object of the present invention is to provide an antenna pointing control device that can easily direct the antenna toward the object.

That is, the antenna pointing control device of the present invention provides a movable body rotatably mounted with an antenna that moves in a medium at least a direction pointed by a predetermined direction on the movable body and a relative velocity of the movable body with respect to the medium. relative velocity detection means for detecting a relative velocity vector of the moving body with respect to the medium; and displacement detection means for detecting a displacement vector of the moving body during a required time from the relative velocity vector and the flow velocity vector of the medium. and a known position vector connecting the displacement vector, the known position of the mobile body, and the fixed base station position to connect the new position of the mobile body after the required time and the position of the base station. The present invention is characterized in that it comprises a position detecting means for detecting a new position vector, and the antenna is directed in the direction of the new position vector at the new position.

The antenna pointing control device of the present invention is particularly suitable for use in emergency reporting at sea using small fishing boats, etc., but it can of course also be applied to aerial or land-based moving objects such as aircraft, helicopters, and automobiles. It is.

The invention will be explained in detail below by way of example embodiments with reference to the drawings.

First, the principle of the present invention will be explained with reference to FIG. 1 regarding an example in which the present invention is applied to a ship. In FIG. 1, O is a fixed base station,
If P is the position of the ship at the starting point on the coastline, it is easy to find the direction and magnitude of the vector from the starting point P to the base station O, that is, the reference position vector 〓 ₀ on the map. . Furthermore, if the relative speed vector of the ship to the seawater immediately after departure, that is, the ship speed vector, is ₀ , and the speed vector of the tidal current or ocean current, that is, the tidal current vector, is ₀ , then the absolute speed vector representing the progress of the ship ₀ is the ship speed. By combining the vector 〓 ₀ and the flow velocity vector 〓 ₀ , it is determined by the following formula.

〓 ₀ = 〓 ₀ + 〓 ₀ ...(1) Then, after the required minute time Δt, the ship moves to position Q.
However, the new position vector 〓 ₁ for that position Q is the product of the absolute velocity vector 〓 ₀ and the minute time Δt, then the displacement vector of the ship and the reference position vector 〓 ₀ are synthesized to form the following equation. It is determined by

〓 ₁ =〓 ₀ −〓 ₀・Δt ...(2) Similarly, ship speed vector at point Q〓
₁ and flow velocity vector〓 From ₁ to absolute velocity vector〓
₁ , and based on the absolute velocity vector 〓 ₁ and the above-mentioned position vector 〓 ₁ , a new position vector 〓 ₂ after Δt can be further calculated. As described above, by repeating the above calculation while measuring the ship speed vector 〓 and the current velocity vector 〓 at each time, the position vector 〓 at an arbitrary time can be obtained. Note that the direction of the position vector 〓 indicates the direction in which the transmitting antenna on the ship should be directed, and the relative position of the ship with respect to the base station can be known from the magnitude and direction of the position vector 〓.

Next, the mutual relationship of each vector mentioned above is expressed as
FIG. 3 shows an example of the basic configuration of the device of the present invention which performs antenna directivity control based on these vectors.

In the configuration shown in FIG. 3, first, in the transmitting antenna azimuth detection control section 1, the transmitting antenna T
The angle β between the pointing direction and the bow direction is converted into a digital value, for example, an 8-bit binary number, by an angle encoder E, and is input to the calculation unit 5. On the other hand, the calculation section 5
As will be described later, the base is calculated from the bow azimuth α detected by the bow azimuth detection section 2, the boat speed v detected by the boat speed detection section 3, and various data set in the data setting section 4. Based on the azimuth θ, the digital value of the error angle Δ in the directivity direction of the transmitting antenna T calculated by Δ=α+β−θ (3) is sent back to the transmitting antenna azimuth detection control unit 1, and the transmitting antenna azimuth is In the angle detection control section 1, the error angle Δ is converted into an analog value by the digital-to-analog converter DA, and the motor M is driven via the servo amplifier A.
The transmitting antenna T is rotated in the direction in which the error angle Δ becomes zero, that is, in the direction in which α+β matches θ.

Next, the heading angle detection section 2 is composed of a flux valve F, a synchro receiver CT, a motor M, and a control circuit C. The azimuth angle α of the bow relative to the magnetic north is detected by operating one point on the circumference in the direction of the magnetic north at all times, and the azimuth angle α is converted into a digital value by the angle encoder E. Enter.

Next, the speed detection unit 3 detects, for example, a propeller,
The ship speed v is measured by a speedometer V made of a generator or the like, converted into a digital value by an analog-to-digital converter AD, and inputted to the calculation section 5.

Next, the data setting section 4 is a section for inputting various data regarding the initial value of the calculation and the power flow into the calculation section 5, and settings are made by, for example, a potentiometer P with a knob in correspondence with the various data. A digital value obtained by converting the DC voltage obtained by analog/digital converter AD or a digital value directly set by digital dial switch D is added to the calculation unit 5, and a read command is issued by the set switch S corresponding to each data. give. A necessary number of these data setting means are provided, and various data such as the base distance l ₀ at the starting point, the base azimuth θ ₀ , the tidal current azimuth γ, and the tidal current speed u are input to the calculation unit 5.

Note that the base distance l ₀ and base azimuth θ ₀ as initial values for calculation can be found on the map, and the tidal current azimuth angle γ and tidal current speed u can be set to pre-estimated values, or Set the digital value actually measured using the above-mentioned speedometer V while the ship is stopped. Furthermore, instead of such predicted values or measured values, the azimuth angle γ and velocity u of the tidal current may be calculated from the high tide time and the current time using the method described later.

Next, the calculation unit 5 has an input/output interface.
The timing pulse generator TP, which consists of IO, arithmetic unit CP, memory ME, etc., generates a pulse train whose repetition period is the minute time Δt in equation (2).
Perform calculations based on each formula (1), (2), and (3), display the new base azimuth θ and base distance l obtained as the result of the calculation on the data display DS, and also calculate the error angle Δ. Transmission antenna azimuth detection control section 1
to rotate the transmitting antenna T. In addition,
The data display DS displays various input data and intermediate results of calculations as necessary, such as the ship's heading angle δ.
It is also possible to display the absolute speed w, etc. Also, as the arithmetic unit CP, it is appropriate to use a microprocessor such as Intel's 8080A, and furthermore, for example, AMD's microprocessor.
If you use an arithmetic processor such as the Am9511 type,
Since the accuracy and speed of calculation can be significantly improved, this method is extremely suitable for achieving the object of the present invention.

Next, to explain in detail the manner of calculation in the calculation unit 5, the above-mentioned equations (1) and (2) are extended to an arbitrary time t, and each of the above-mentioned vectors is expressed by polar coordinates according to FIG. , the relative speed vector of the ship, that is, the speed vector = (v, α), the current speed vector = (u, γ), and the absolute speed vector of the ship = (w, δ), the following (1-a) is obtained. The formula is obtained, 〓=〓+〓 ...(1-a) Also, let the displacement vector of the ship during the minute time Δt be 〓=(x, δ), and the value of the position vector at time t be 〓 =(l, θ) and the value at time t-Δt is 〓 ₋₁ =(l ₋₁ , θ ₋₁ ), then the following equations (2-a) and (2-b) are obtained.

〓=〓・Δt ……(2-a) 〓=〓 _-1 −〓 ……(2-b) Here, using the cosine theorem and the sine theorem,
From equation (1-a), w=√ ² + ² +2 (-) ...(4) δ=α+sin ^-1 [u/vsin(γ-α)] ...(5) is obtained, and (2 -a) Formula and (2-b)
From the formula, x=w・Δt...(6) l=√ ² _-1 + ² -2 _-1 ( _-1 -)...(7) θ=θ _-1 +sin ^-1 [x/lsin(θ _-1 −δ)] …(8) is obtained. Equations (7) and (8) are both recursive equations, and the position vector ((l, θ) at the next time t is calculated from the calculated value of the position vector (l, Therefore, by setting the minute time Δt to an appropriate value, for example Δt=1 second, the ship speed vector (v, α), current velocity vector (u, γ) and departure If the value of the reference position vector (l ₀ , θ ₀ ) at a point is given, the position vector (l, θ) at any time t can be calculated sequentially using equations (4) to (8), and furthermore, , (3), the error angle Δ in the directivity direction of the transmitting antenna T can be determined.

Next, we will explain how to calculate the current speed of a tidal current.Since the direction and speed of a tidal current are a function of the location and time on the ocean, the direction of the tidal current at each position within the expected range of activity on the ocean. and the maximum speed are measured in advance and stored in the memory ME, and when used, the above-mentioned direction and maximum speed are read out from the memory ME corresponding to the position vector (l, θ) calculated as above, and further, Based on the high tide time of the day and the current time,
Current velocity vector of the current at the current time (u,
γ). The current time can be obtained by counting the number of pulses in the timing pulse generator TP after closing the set switch S which sets the digital switch D and gives a read command. For example, the following equation (9) is the simplest approximation formula for the tidal current speed in a sea where the state of the tidal current is known, such as the Seto Inland Sea.

u = u _n sin [2π/T (t - t ₀ )] ...(9) where u is the tidal current speed, u _n is the maximum tidal current speed,
t is the current time, t ₀ is the high tide time, and T is the high tide cycle. Note that the calculation of tidal current velocity is not limited to the above formula (9), but can be calculated using a more precise approximate formula by setting various constants related to the moon phase and season to digital switch D. I can do it.

Next, as another example of the fundamental configuration of the antenna pointing control device of the present invention, FIG. 4 shows the configuration shown in FIG. 3 with an antenna suppression angle detection control section 6 added thereto. In the configuration shown in FIG. 4, the inclinometer I detects the vertical direction, converts the deviation angle of the central axis C from the vertical direction in the inclinometer I into a voltage, and converts the voltage to a servo amplifier A. By driving the motor M to change the inclination angle of the center axis C of the inclinometer I, the center axis C of the inclinometer I can be maintained vertically at all times regardless of the movement of the ship. can. On the other hand, in the calculation unit 5, the transmitting antenna T is calculated using the following equation (10).
Calculate the elevation angle ε at which the should be directed.

ε=tan ^-1 (h/l) ...(10) Here, l is the distance to the base station calculated by equation (7), and h is the distance between the receiving antenna of the base station and the transmitting antenna on the ship. This is the altitude difference between the two points and is set by one of the digital switches D in the data setting section 4. Note that a more precise calculation formula that takes into account the curvature of the earth can also be used instead of formula (10). Therefore, the digital value of the elevation angle ε calculated using equation (10) is converted into a digital-to-analog converter.
Convert to analog value using DA. On the other hand, the difference in inclination angle between the transmitting antenna T and the central axis C of the vertically independent inclinometer I is converted into a voltage by the potentiometer P, and further converted into an analog value of the elevation angle ε of the transmitting antenna T mentioned above. By taking the difference from the corresponding voltage, amplifying it with a servo amplifier A, and supplying it to a motor M to drive a transmitting antenna T,
The elevation angle of the transmitting antenna from the horizontal plane perpendicular to the vertical direction is made to match the above-mentioned elevation angle ε calculated by the calculation unit 5.

Further, in the configuration shown in FIG. 4, an angle encoder is used in place of the potentiometer P, and the elevation angle of the transmitting antenna T is controlled by the same configuration as in the transmitting antenna azimuth detection control section 1. You can also do it. That is, the inclination angle of the transmitting antenna T with respect to the horizontal plane is converted into a digital value and inputted to the calculation unit 5, and the calculation unit 5 calculates the difference between the inclination angle and the elevation angle ε calculated by equation (10), The difference, that is, the error angle can be converted into an analog value and then amplified to drive the motor M.

Furthermore, in the configuration shown in FIG.
is fixed to the ship and converts the movement of the ship into a voltage value,
Although the inclination angle of the transmitting antenna T can be controlled based on the difference between the voltage value corresponding to the analog value of the elevation angle ε and the above-mentioned voltage value, the accuracy of the control decreases.

In addition, in the configuration shown in FIG. 4, only the elevation angle of the transmitting antenna T is controlled, but the same configuration also controls the rotational operation of the transmitting antenna T around the radio wave emission direction, that is, the polarization plane of the emitted radio wave. It is also possible to correct the inclination. However, in general, losses due to tilting of the plane of polarization due to ship motion are relatively small, and if circularly polarized waves are used, such losses will not occur at all.

In the above description of the heading angle detection unit 2 shown in FIG. 3, a method for detecting the geomagnetic direction has been described, but in general, other means for detecting a reference direction fixed on the earth, e.g. It is also possible to use a gyroscope, a gyroscope, a combination of a geomagnetic detector and a gyroscope, etc. On the other hand, in the above explanation regarding the ship speed detection section 3, the relative speed of the ship with respect to seawater is used. We have described the method of directly measuring
If the number of rotations of the propeller shaft of a ship is proportional to its relative speed, the relative speed can be measured indirectly by measuring the number of rotations of the propeller shaft;
In the above description of the transmitting antenna elevation angle detection control section 6 shown in the figure, a method of using an inclinometer for detecting the vertical direction was described, but other means for detecting the gravity direction or the horizontal direction, such as a pendulum, a level In addition, in the explanation of the calculation in the calculation unit 5, the initial value of the position vector (l ₀ , θ
₀ ) stated that the value at the starting point P shown in Figure 1 should be found on the map and used. When passing the target, the value of the position vector (l ₀ , θ ₀ ) regarding that specific target is determined on the map, and the value is input to the calculation unit 5 to restart the above-mentioned recurrence calculation anew. , it is also possible to increase the accuracy of calculation. In addition, regardless of the presence or absence of a specific target as described above, at any time, while communicating with the base station using the conventional method, the transmitting antenna T can be manually moved in the direction where the received electric field at the base station is maximized. The azimuth of the base station corrected in this way is set as an initial value θ ₀ , and the calculation unit 5
It is also possible to improve the pointing accuracy after that time by inputting the following information. In addition, in the calculation of equation (3) in the calculation unit 5, the base station azimuth angle initial value θ ₀ in the data setting unit 4 is substituted for the base station azimuth angle θ obtained as the calculation result, and the potentiometer with knob is A manual mode control mechanism may also be provided in which the transmitting antenna T rotates in accordance with the rotation of the meter P. According to such a manual mode control mechanism, the above-described manual pointing adjustment and setting of the base station azimuth initial value θ ₀ can be easily performed.

As is clear from the above description, according to the present invention, the following remarkable effects can be obtained.

(1) Not only can the transmitting antenna on a mobile object be automatically directed towards the base station at all times, but also the current position and direction of movement of the mobile object can be displayed, so it can be When reporting on a marine accident under difficult circumstances, it is possible to arrive at the scene of the incident safely and quickly.

(2) Since the required pointing direction is calculated by a microcomputer without using a large-scale mechanism such as a rotating antenna for detecting the direction of arrival of radio waves, the antenna pointing control device can be constructed in a small and lightweight manner. , small fishing boats, etc. can be used for highly mobile reporting.

(3) Directional control of the antenna can be performed only by calculations on the mobile unit, independent of the base station, so there is no particular need for radio waves to be transmitted from the base station to the mobile unit. Therefore, it is extremely advantageous in terms of radio wave control to prevent interference of radio waves such as communication and reporting when an incident occurs.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the operating principle of the antenna pointing control device of the present invention, Fig. 2 is a vector diagram showing the interrelationship of the vectors, and Fig. 3 is an example of its basic configuration. block diagram,
FIG. 4 is a block diagram showing another example. 1... Transmission antenna azimuth detection control unit, 2...
Heading angle detection unit, 3... Ship speed detection unit, 4... Data setting unit, 5... Calculation unit, 6... Transmission antenna elevation angle detection control unit, O... Base station, T... Transmission antenna, E ...Angle encoder, M...Motor, A
...Amplifier, DA...Digital-to-analog converter, F...Flux valve, CT...Synchronized receiver, C...Control circuit, V...Speedometer, AD...
...Analog-to-digital converter, P...Potentiometer, D...Digital switch, S...Set switch, IO...Input/output interface, DS
...Data display, CP...Calculator, ME...Memory, TP...Timing pulse generator, I...Inclinometer, C...Central axis.

Claims (1)

[Claims] 1 A moving body rotatably mounted with an antenna and moving in a medium is provided with at least an image of the moving body relative to the medium based on the direction pointed by a predetermined direction on the moving body and the relative velocity of the moving body with respect to the medium. relative velocity detection means for detecting a relative velocity vector; displacement detection means for detecting a displacement vector of the movable body during a required time from the relative velocity vector and the flow velocity vector of the medium; and the displacement vector and the movable body. position detection for detecting a new position vector connecting the new position of the mobile object and the position of the base station after the required time from the known position vector connecting the known position of the mobile object and the position of the fixed base station; An antenna pointing control device comprising means for directing the antenna in the direction of the new position vector at the new position.