JPH07170464A - Television receiver for mobile body - Google Patents

Abstract

PURPOSE:To obtain a stably sharp television picture even when a mobile body moves. CONSTITUTION:A detection means 5 of the GPS system employing a positioning satellite detects a current position and a progressing direction of a mobile body, the position of a transmission station of a television broadcast and the service area and either of vertically polarized and horizontally polarized waves are stored in a memory 9 and directive antennas 1, 2 are driven around a perpendicular line. Thus, the antennas 1, 2 are always directed toward a receptible transmission station and a sharp television picture is obtained with excellent reception sensitivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver used in a moving body such as a ship, train or bus.

[0002]

2. Description of the Related Art A typical prior art is, for example, Japanese Patent Laid-Open No.
6-57365, JP-A-61-5682 and JP-A-4
-160905 and the like. In these prior arts, a plurality of television antennas are fixed to a mobile body, and by comparing the output signal levels of the respective antennas, the antenna with the best reception condition is selected, and the output from the selected antennas is selected. Is receiving a television broadcast by.

[0003]

In each of the above prior arts, all the antennas are fixed to the moving body.
Of these antennas, even if the antenna is switched to the antenna with the best reception status to receive the television broadcast, the selected antenna does not always face the transmitting station of the television broadcast exactly. Therefore, a clear television image may not be obtained.

Further, in this prior art, since a finite number, for example, 2 to 4 antennas are used to cover the 360 ° direction, it is necessary to use an antenna having a certain wide directivity. An antenna having such a wide directivity has lower reception performance than an antenna having a strong directivity. Therefore, it is difficult to obtain a clear television image.

Furthermore, in each of these prior arts, each antenna receives both horizontally polarized waves and vertically polarized waves, and thus the reception sensitivity is reduced. Therefore, a clear television image may not be obtained.

It is an object of the present invention to provide a television receiver for a mobile body capable of obtaining a clear television image.

[0007]

According to the present invention, there is provided a detecting means for detecting a current position and a traveling direction of a moving body, a memory for storing a position of a transmitting station for television broadcasting, a directional antenna, A moving body, comprising: driving means for angularly driving the antenna about a vertical axis; and control means for directing the antenna to the transmitting station by the driving means in response to the output of the detecting means and the memory. It is a television receiver.

Further, according to the present invention, a service area capable of receiving a plurality of television broadcasts is stored in the memory, and the control means selects a television broadcast transmission station whose current position is within the service area. It is characterized in that the driving means is operated.

Further, according to the present invention, the antenna is provided with a vertically polarized wave and a horizontally polarized wave, respectively, and the memory has:
Stores whether the television broadcast from each of the multiple transmitting stations is transmitted in vertical polarization or horizontal polarization,
The control means selects an antenna for vertical polarization when the television broadcast is transmitted by vertical polarization, selects an antenna for horizontal polarization when it is transmitted by horizontal polarization, and outputs the output of each antenna. It is characterized by deriving.

Further, the detecting means of the present invention is a positioning device which calculates and calculates the present position and the traveling direction based on the received signals from a plurality of positioning satellites that orbit the earth.

Still further, according to the present invention, the detecting means includes
An azimuth sensor is provided together with the positioning device, and the detection result of the positioning device is used when the traveling speed of the moving body is equal to or more than a predetermined first value in the traveling direction, and when the traveling speed is less than the first value, the azimuth sensor is detected. It is characterized by using the detection result.

According to the present invention, a calibrating means is provided in association with the azimuth sensor, and the calibrating means is provided for the azimuth sensor when the moving speed becomes equal to or more than a predetermined second value equal to or more than the first value. The difference between the detection result and the detection result of the positioning device is obtained, and when the angular displacement of the antenna is driven by the output of the direction sensor, the output of the direction sensor is corrected by the difference and output.

Furthermore, the azimuth sensor of the present invention is a magnetic azimuth sensor.

[0014]

According to the present invention, the moving body is provided with the detecting means for detecting the current position and the traveling direction, and in response to the detection result, the position of the television broadcasting transmitting station stored in the memory is The drive means is operated by the control means so that the directional antenna is oriented, and the antenna is angularly displaced about the vertical axis. In this way, it is possible to always receive a television broadcast in a good reception state by using an antenna having a sharp directivity and thus a high reception performance, and to obtain a clear television image.

Further, preferably, the memory also stores a service area in which the television broadcast can be received, and a transmitting station located in the service area in accordance with the current position of the moving body detected by the detecting means. Can be selected and received, and all the television broadcasts transmitted by those transmitting stations can be selected and received.

Furthermore, preferably, the memory also stores whether the television broadcast of each transmitting station is vertically polarized or horizontally polarized, and the mobile body stores vertically polarized waves and horizontally polarized waves. A directional antenna for polarized waves is installed, switching each antenna according to the polarization direction of the transmitting station,
This can improve the reception sensitivity.

Further, preferably, the detecting means is a positioning device which calculates and calculates the current position and the traveling direction based on the received signals from a plurality of positioning satellites that orbit the earth.

Therefore, compared with the case where the current position is obtained by dead reckoning using a gyro sensor or the like,
The detection accuracy can be dramatically improved.

Further preferably, the detecting means is
An azimuth sensor realized by a magnetic azimuth sensor or the like is provided together with the positioning device, and the detection result of these positioning device or the azimuth sensor is selectively used as the traveling direction. That is, the detection result of the positioning device is used when the traveling speed is a predetermined first value, for example, 10 km / h or more, and the detection result of the azimuth sensor is used when the traveling speed is less than the first value.

As described above, when the detection result of the traveling direction of the positioning device has many errors due to the decrease of the traveling speed, an orientation sensor such as a magnetic orientation sensor whose detection accuracy does not change with the decrease of the traveling speed is used. Thus, as the azimuth sensor, a relatively inexpensive azimuth sensor such as the magnetic azimuth sensor can be used when the traveling speed is low, without using an unnecessarily expensive high-precision sensor such as an optical fiber gyro sensor. By performing the detection, it is possible to achieve both low cost and high accuracy.

Further, preferably, in the configuration using the positioning device and the azimuth sensor as the detecting means, a calibrating means is provided in association with the azimuth sensor. When the traveling speed reaches a predetermined second value, for example, 30 km / h or more, at which the traveling speed is equal to or higher than the first value and the positioning device has sufficient accuracy, the calibrating means outputs the detection result of the azimuth sensor at that time. The difference with respect to the detection result of the positioning device is obtained. Using this difference,
When the traveling speed at which the angular displacement of the antenna is driven by the output of the azimuth sensor is low, the detection result of the azimuth sensor is calibrated and output to obtain a relatively accurate traveling direction even when the traveling speed is low. You can

[0022]

1 is a block diagram showing the electrical construction of a television receiver for a mobile body according to an embodiment of the present invention.
The vertically polarized television antenna 1 and the horizontally polarized television antenna 2 are rotated by a rotating shaft 4 which is vertical to the moving body 3 shown in FIG. 2 while the moving body 3 travels in a horizontal plane. Mounted as possible. The moving body 3 is shown in FIG.
Although a vehicle such as a bus is shown in, the other examples may be a ship and a train,
Further, it may be a moving body that moves along a predetermined moving route such as a bus or a train as described above, or a moving body that moves on another route.

The mobile unit 3 has a GPS (Gloval Positionin
g System, Global Positioning System) detection means 5 is provided. The detecting means 5 includes an antenna 6 and a GPS unit 7. As shown in FIG. 3, the antenna 6 is a microstrip line antenna provided on the roof of the moving body 3 and has an elevation angle θ of 10 degrees or more when horizontally arranged, and covers a wide range. Receive signals from at least four positioning satellites. GPS
Based on the signal from this antenna 6, the unit 7
The distance from each positioning satellite is calculated, triangulation is performed from the distance and the position of each satellite, the three-dimensional current position including latitude and longitude is calculated, and the Doppler shift amount of the signal from each positioning satellite is calculated. Based on, the traveling direction 18 and the traveling speed are detected.

The output of the GPS unit 7 is given to the control means 8 realized by a microcomputer or the like. A memory 9 is connected to the control means 8. In the memory 9, as shown in Table 1 below, position information of latitudes and longitudes of a plurality of transmission stations of each television broadcast, and information indicating a transmission polarization plane of vertical polarization or horizontal polarization and a service area. And are stored at each transmitting station.

[0025]

[Table 1]

In the polarization column of Table 1 above, "1" indicates that the plane of polarization is horizontal, and "0" indicates that the plane of polarization is vertical. The control means 8 determines the receiving target transmitting station based on the position and service area of the transmitting station regardless of whether the moving route is known in advance, and the antennas 1 and 2 move in the direction of the transmitting station. The pulse motor 10 is driven so as to face, and the antennas 1 and 2 are angularly displaced about the vertical axis. The outputs from the antennas 1 and 2 are given to the television receiver 12 via the changeover switch 11. The control means 8 controls the switching state of the changeover switch 11 in accordance with the polarization plane of the television broadcast to be received.

The operation of the control means 8 as described above is shown in FIG. Go to step n2 from step n1
The S type detection means 5 detects the current position and the traveling direction of the moving body 3. The reference numeral 13 in FIG.
Represents the current position of, and its latitude and longitude are indicated by xa and ya, respectively. In the next step n3, the transmitting station where the current position 13 of the mobile unit 3 is within the service area is selected and read from the memory 9 as the target transmitting station. Thus, for example, when the latitude and the longitude of the position 14 of the transmitting station are x1 and y1, respectively, the direction 15 of the antennas 1 and 2 is made to coincide with the virtual straight line 16 connecting the positions 13 and 14. The rotation angle θ1 is calculated in step n4. The pointing directions of the antennas 1 and 2 are assumed to be parallel within one plane.

In step n5, the motor 10 is driven to rotate the antennas 1 and 2 by the rotation angle θ1. At step n6, one of the antennas 1 and 2 that matches the polarization plane of the transmitting station is selected, and the changeover switch 11 is set so that the signal from the selected antenna 1 or 2 is given to the television receiver 12. Control. By constantly performing such a series of operations, the antennas 1 and 2 are
Can always be directed to a transmitting station whose current position of the mobile 3 is included in the service area.

Although the detecting means 5 is of the GPS type in the above-mentioned embodiment, it may have another structure as another embodiment of the present invention. The antennas 1 and 2 may be Yagi antennas, for example.

As described above, according to the present invention, since the receivable transmitting station is always tracked, antennas having a strong directivity can be used as the antennas 1 and 2, and a clear television image can be obtained. Further, the service area of each transmitting station is also stored in the memory 9, so that it is possible to select and receive all the television broadcasts transmitted by the transmitting stations in the service area. Furthermore, since the vertical polarization antenna 1 and the horizontal polarization antenna 2 are switched and received, the polarization directions can be changed by switching these two antennas 1 and 2 according to the polarization direction of the transmitting station. Regardless of this, high reception sensitivity can always be obtained.

FIG. 6 is a block diagram showing an electrical construction of a television receiver for a mobile body according to another embodiment of the present invention. This embodiment is similar to the above-mentioned embodiment, and the corresponding portions are the same. With the reference sign. It should be noted that in this embodiment, the detecting means 5a is provided with the magnetic bearing sensor 21 together with the GPS receiver including the antenna 6 and the GPS unit 7. GPS unit 7
Outputs the current position information to the control means 8 as described above, and also derives outputs indicating the traveling direction and the traveling speed. The control means 8 switches the output in the traveling direction to the detection result of the magnetic azimuth sensor 21 and outputs it to the GPS unit 7 when the traveling speed becomes less than a predetermined first speed V1, for example, 10 km / h.

FIG. 7 is a block diagram showing an electrical configuration of the magnetic direction sensor 21. This magnetic direction sensor 21
Generally includes a detection circuit 22 and an arithmetic processing unit 23 implemented by a microcomputer or the like. A sensor body 24 provided in the detection circuit 22
Is formed by winding two pairs of coils 27, 28; 29, 30 around an annular core 25 made of a ferromagnetic material. The exciting coils 27 and 28 are wound so as to be orthogonal to each other on the diameter line of the core 25. Similarly,
The detection coils 29 and 30 are wound around the core 25 so as to be orthogonal to each other, and the excitation coils 27 and 28 and the detection coils 29 and 30 are arranged so as to be displaced by 45 degrees in the circumferential direction. The sensor body 24 is used with an annular core 25 placed horizontally.

The exciting coil 27, 28 is provided with an oscillator 3
The oscillation signal from 1 is commonly given to the oscillation signal of the frequency fo divided by the frequency divider 32. As a result, from the detection coils 29 and 30, as shown by reference characters L1 and L2 in FIG. The outputs of the detection coils 29 and 30 are input to the phase detection circuits 33 and 34, respectively. Phase detection circuit 3
3 and 34 also include the frequency 2 from the frequency divider 32.
Since the oscillating signal of fo is given, therefore, the phase detecting circuits 33 and 34 output a beat signal having a frequency of approximately fo. This beat signal is supplied to the integrating circuits 35 and 36.
After being respectively integrated with each other, they are amplified by the DC amplifiers 37 and 38 and input to the arithmetic processing unit 23. As a result, the arithmetic processing unit 23 can detect the relative azimuth of magnetic north with respect to the reference azimuth 41.

A stabilizing power supply circuit 39 and a reference voltage generating circuit 40 are also provided in the detecting circuit 22, and after the power from the power supply is stabilized by the stabilizing power supply circuit 39, a reference voltage is generated. It is supplied after being limited by the circuit 40 to a voltage suitable for each circuit in the detection circuit 22.

The television receiver thus constructed is attached to a passenger ship 42 as shown in FIG. 9, for example. In this passenger ship 42, the magnetic direction sensor 21 is installed in, for example, a snake control room so that the reference direction 41 of the magnetic direction sensor 21 coincides with the axis 43 of the passenger ship 42.

FIG. 10 is a flow chart for explaining the operation of the above-mentioned television receiving apparatus, which is shown in FIG.
Similar to the operation shown by, the same reference numerals are given to corresponding parts. In this embodiment, the process moves from step n1 to n11 and the GPS unit 7 obtains the current position and the traveling speed V. In step n12, it is determined whether or not the traveling speed V is equal to or higher than the speed V1, and if so, in step n13, the detection result θG of the GPS unit 7 is set to the traveling direction θ, and then to step n3. If not, after the detection result θM of the magnetic bearing sensor 21 is set to the traveling direction θ in step n14,
The process moves to step n3.

In this way, when the error of the GPS detection result θG is relatively large and the error due to the influence of the ocean current is less than the speed V1, the detection result θM of the magnetic azimuth sensor 21 is used to obtain the speed V1 or more. Then, it is possible to detect the traveling direction θ with high accuracy based on the detection result θG of the GPS unit 7. Further, when the passenger ship 42 is at a low speed such as when the passenger ship 42 is stopped, the detection result θM of the magnetic bearing sensor 21 is used to detect the accuracy by the GPS. The direction of travel can be accurately determined by compensating for the decrease.

Further, by using the GPS and the azimuth sensor in combination as described above, it is not necessary to use the azimuth sensor such as the optical fiber gyro sensor which is inaccurately high in accuracy in the magnetic azimuth sensor 21, which is relatively inexpensive. With such a configuration, the accuracy at low speed can be improved.

When a highly accurate azimuth sensor such as the optical fiber gyro sensor is used, it is not necessary to switch the output θG of the GPS unit 7 in this way, and only the output θM from the azimuth sensor is used. Should be used. Further, when an output is obtained from a highly accurate navigation gyro sensor provided on the ship side, such a direction sensor may be omitted.

FIG. 11 is a block diagram showing the electrical construction of a television receiving apparatus according to still another embodiment of the present invention, which is similar to the above-mentioned embodiment and the same reference numerals are given to corresponding portions. It should be noted that in this embodiment, the detecting means 5b
In addition, a calibration circuit 50 for calibrating the output from the magnetic direction sensor 21 is provided. Calibration circuit 50
Receives the information about the traveling direction and the traveling speed from the GPS unit 7, and detects the GPS unit 7 when the traveling speed V is a second predetermined speed V2 which is equal to or higher than the speed V1, for example, 30 km / h or higher. Result θG
Error Δθ of the detection result θM of the magnetic azimuth sensor 21 with respect to
When the speed V is less than the speed V1 and the output from the magnetic azimuth sensor 21 is used, the output is corrected by the error Δθ and output.

That is, as shown in FIG. 12, step n
At 12 and n13, after the speed V is equal to or higher than the speed V1 and the detection result θG of the GPS unit 7 is set in the traveling direction θ, the process proceeds to step n21, and it is determined whether or not the speed V is equal to or higher than the speed V2. , If so, step n2
In step 2, the detection result θM of the magnetic azimuth sensor 21 is read, and in step n23, the difference Δ between the detection results θG and θM.
After θ is obtained, the process proceeds to step n3, and if not, the process directly proceeds to step n3. Using the error Δθ obtained in this way, the traveling direction θ once set in the detection result θM of the magnetic azimuth sensor 21 in step n14 is
Further, after being corrected by the error Δθ in step n24, the process proceeds to step n3.

In this way, by calibrating the detection result θM of the magnetic direction sensor 21 with respect to the factors that disturb the geomagnetism of the deck and the bridge, the detection accuracy can be further improved even if the inexpensive magnetic direction sensor 21 is used. it can.

[0043]

As described above, according to the present invention, the directional antenna is determined based on the current position and traveling direction of the moving body detected by the detecting means and the position of the transmitting station stored in the memory. The drive means can drive the angular displacement about the vertical axis, thus directing the antenna to the transmitting station. Therefore, a television broadcast can be received by an antenna having sharp directivity and high reception performance, and a clear television image can always be obtained. In addition, such a directional sharp antenna,
The receiver sensitivity can be improved because it can be automatically directed to the direction of the transmitting station of the television broadcast.

Further, preferably, a transmitting station in which the current position of the mobile body is within the service area is selected and an antenna is driven toward the transmitting station, whereby all the television stations transmitting by these transmitting stations are selected. Broadcast can be received.

Still more preferably, it is possible to automatically select an antenna that matches the transmission polarization plane, thereby improving the reception sensitivity. In this way, a stable and clearer television image can be obtained even while the moving body is moving.

Further, preferably, the detecting means is a positioning device that calculates the current position based on the received signals from a plurality of positioning satellites that orbit the earth, so that the current position can be obtained with high accuracy.

Further preferably, the detecting means is
Along with the positioning device, an azimuth sensor such as a magnetic azimuth sensor is provided, and the detection result of the azimuth sensor is used when the traveling speed of the moving body decreases below the first speed and the accuracy of detection of the traveling direction by the positioning device decreases. Highly accurate and low cost are achieved by detecting the traveling direction with high accuracy at normal times and with a low-cost structure at low speeds by using a relatively inexpensive direction sensor such as the magnetic direction sensor. can do.

Further, preferably, when the traveling speed of the moving body becomes equal to or higher than the first speed and equal to or higher than the second speed, the detection result of the azimuth sensor at that time is corrected by the detection result of the positioning device. It is possible to calibrate errors due to body structures and the like, and it is possible to further improve the detection accuracy even when using a low-cost direction sensor.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall electrical configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a simplified configuration of a moving body 3.

FIG. 3 is a vertical cross-sectional view showing an antenna 6 included in the GPS type detection means 5.

FIG. 4 is a flow chart for explaining the operation of control means 8.

FIG. 5 is a diagram for explaining a calculation operation of a control means 8.

FIG. 6 is a block diagram showing an electrical configuration of another embodiment of the present invention.

7 is a block diagram showing an electrical configuration of a magnetic direction sensor 21 used in the embodiment shown in FIG.

FIG. 8 is a diagram for explaining the detection operation of the magnetic direction sensor 21.

9 is a perspective view of a passenger ship 42 in which the embodiment shown in FIG. 6 is used.

10 is a flowchart for explaining the operation of the embodiment shown in FIG.

FIG. 11 is a block diagram showing an electrical configuration of still another embodiment of the present invention.

12 is a flowchart for explaining the operation of the embodiment shown in FIG.

[Explanation of symbols]

 1 Vertically polarized television antenna 2 Horizontally polarized television antenna 3 Moving body 4 Rotation axis 5, 5a, 5b Detection means 6 Microstrip line antenna 7 GPS unit 8 Control means 9 Memory 10 Pulse motor 11 Changeover switch 12 Television John receiver 21 Magnetic direction sensor 41 Reference direction 42 Passenger ship 43 Axis 50 Calibration circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // G01S 5/14 4240-5J (72) Inventor Shin Hiramatsu 1-1 Kawasaki-cho, Akashi-shi, Hyogo No. Kawasaki Heavy Industries Ltd., Akashi Plant (72) Inventor Kazuyuki Nakamura 1-1 Kawasaki-cho, Akashi City, Hyogo Prefecture Kawasaki Heavy Industries Ltd., Akashi Plant

Claims (7)

[Claims] 1. A detecting means for detecting a current position and a traveling direction of a mobile body, a memory for storing a position of a transmitting station of a television broadcast, a directional antenna, and an antenna for arranging the antenna around a vertical axis. A television receiver for a mobile body, comprising: a drive unit for driving displacement, and a control unit for directing an antenna to a transmitting station by the drive unit in response to the detection unit and the output of the memory. 2. A service area capable of receiving a plurality of television broadcasts is stored in the memory, and the control means selects a television broadcast transmitting station whose current position is within the service area to drive the drive means. The television receiver for a mobile body according to claim 1, which is operated. 3. The antenna is provided for vertical polarization and horizontal polarization, respectively, and the television broadcast from each of the plurality of transmitting stations is transmitted in either vertical polarization or horizontal polarization in the memory. The control means selects the vertical polarization antenna when the television broadcast is transmitted in the vertical polarization, and selects the horizontal polarization antenna when the television broadcast is transmitted in the horizontal polarization. The mobile television receiver according to claim 1 or 2, wherein the output of each antenna is derived. 4. The positioning device is a positioning device that calculates and calculates the current position and the traveling direction based on received signals from a plurality of positioning satellites that orbit the earth. The television receiver for a mobile body according to any one of 3 above. 5. An azimuth sensor is provided in the detecting means together with the positioning device, and when the traveling speed of the moving body in the traveling direction is equal to or more than a predetermined first value, the detection result of the positioning device is used, The television receiver for a mobile body according to claim 4, wherein the detection result of the azimuth sensor is used when it is less than the first value. 6. A calibrating means is provided in relation to the azimuth sensor, and the calibrating means detects the detection result of the azimuth sensor when the moving speed becomes equal to or more than a predetermined second value equal to or more than the first value. The television reception for a mobile body according to claim 5, wherein a difference with respect to a detection result of the positioning device is obtained, and when the angular displacement of the antenna is driven by the output of the azimuth sensor, the output of the azimuth sensor is corrected by the difference and output. apparatus. 7. The television receiver for a mobile body according to claim 5, wherein the azimuth sensor is a magnetic azimuth sensor.