JP3305805B2 - Automatic tracking antenna device for satellite reception - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tracking antenna for satellite reception which is used by being mounted on a moving body such as a vehicle or a ship.

[0002]

2. Description of the Related Art Conventionally, an automatic tracking antenna apparatus for satellite reception which is used by being mounted on a moving body such as a vehicle or a ship is a horizontal type in which the beam direction of the antenna is horizontally rotated as the moving body moves in the left and right directions. It has a directional rotation tracking mechanism and an elevation direction tracking mechanism that displaces the beam direction of the antenna in the elevation direction with the vertical tilt of the moving body, and the antenna itself performs the elevation direction tracking mechanism and frequency-converts the received signal. Noise block converter (LNB) for extracting
It is equipped with.

For this reason, the low-noise block converter (LN) is provided between the moving body fixed portion side and the rotating portion side.
A high frequency rotary coupler for introducing the received signal from B) to the fixed unit side and a DC coupler for transmitting a power supply and a control signal for elevation tracking to the rotary unit side are required.

[0004]

In the conventional automatic tracking antenna apparatus described above, the horizontal rotation tracking mechanism operates with respect to the horizontal displacement, and the elevation tracking mechanism operates with respect to the elevation displacement. Therefore, both the rotating system and the coupling system are complicated, heavy and large, and there is a problem that it is difficult to reduce the size, weight, and cost, which are easily spread.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to perform tracking in both the horizontal and elevation directions by two horizontal rotation driving means, thereby achieving a small, lightweight, and low-cost automatic tracking antenna apparatus for satellite reception. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION An automatic tracking antenna apparatus for satellite reception according to the present invention comprises an antenna having an antenna beam having a preset tilt angle and a rotatable antenna with respect to an axis perpendicular to the antenna surface. Antenna rotation fixing means arranged on the moving body fixing portion, antenna rotation driving means for rotating the antenna in the moving body fixing portion, a beam reflecting plate for reflecting the beam of the antenna in a satellite direction, and this beam A reflector rotating and fixing means for disposing a reflecting plate so as to be freely rotatable in the horizontal direction and disposing the reflector on the moving body fixing portion; a reflecting plate rotating and driving means for rotating and driving the beam reflector in the moving body fixing portion; Control means for controlling rotation of the antenna rotation driving means and the reflector rotation driving means in accordance with the reception signal level. .

[0007]

Since the antenna beam and the beam reflector have a preset tilt angle and can be freely rotated in the horizontal direction, tracking in both the horizontal and elevation directions can be performed only by the horizontal rotation driving means. For example, if the tilt angle is 10 °, the elevation angle direction can be ± 10 ° and the horizontal direction can be 360 °. Therefore, the tracking mechanism is simplified, and the size, weight, and cost can be reduced.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an automatic tracking antenna device for satellite reception. The automatic tracking antenna device includes a beam tilt plane antenna 10.

The flat antenna 10 has an antenna beam having a preset tilt angle, and a low-noise block converter (LNB) 12 is disposed at the center of the lower surface thereof via a high-frequency rotary coupler 11. .

Low noise block converter (LNB)
Reference numeral 12 denotes an intermediate frequency band which incorporates a high frequency circuit board (SHF) and an intermediate frequency circuit board (IF), and which corresponds to a satellite input signal supplied from the planar antenna 10 via the high frequency rotary coupler 11 to a receiver input. Convert and amplify. The planar antenna 10 and the low noise block converter (LN
B) 12, placed and fixed on a circular fixed base 13 fixed to the moving body.

The fixed base 13 is provided with two rising portions 13a and 13b concentrically along the peripheral edge portion. The rotating portions 14a and 13b having a built-in ball bearing in the rising portions 13a and 13b. An annular antenna rotating frame 15a and a reflector rotating frame 15b are provided via 14b. Then, the planar antenna 10 is mounted on the antenna rotating frame 15a, and one end of the planar beam reflecting plate 16 which is sufficiently larger than the radiation plate surface of the planar antenna 10 is positioned at an arbitrary position on the reflecting plate rotating frame 15b. Mounted via The reflector rotating frame 15b rotates the reflector 16 in the horizontal direction on the outer periphery of the planar antenna 10. The reflection plate 16 is adjusted by the elevation adjustment mechanism 17 so that the antenna beam of the planar antenna 10 is reflected in the elevation direction corresponding to the arrival direction of the satellite radio wave.

The low noise block converter (LN)
B) The received signal converted into the intermediate frequency band by 12 is supplied to a receiver via a distributor 18 (IF output), and the other is converted into a DC signal corresponding to the received signal level and controlled. Is supplied to the vessel 19.

Further, the automatic tracking antenna device is provided with a displacement sensor for detecting displacement of the moving body in the horizontal direction and / or the elevation direction or both directions, for example, a GPS device, a compass, and the like. A position signal corresponding to the displacement of the body is supplied to the controller 19.

On the other hand, an antenna rotating frame 15a for horizontally rotating the planar antenna 10 and a reflector rotating frame 15b for horizontally rotating the beam reflector 16 are roller-driven by an antenna motor (M) 21 and a reflector motor (M) 22, respectively. It is rotated via 23,24. The motor 21,
A pulse motor is used as 22, and the motor drivers 25 and 2 are driven in response to a motor drive control signal from the controller 19.
6 driven.

As described above, tracking is performed in both the horizontal and elevation directions with respect to the satellite by the two horizontal rotation driving means for the plane antenna 10 and the plane beam reflector 16.
In addition, for example, a DC power supply for a vehicle is input to the power supply circuit 27 and distributed and supplied to the control system and the drive system.

The controller 19 has a CPU (macro processor) controlled by a program. When the level of the received signal supplied from the distributor 18 is equal to or lower than a predetermined level Lth sufficient to receive a video signal, the controller 19 receives the received signal. Planar antenna 10 and beam reflector 1 so that the signal level is maximized.
Acquisition control (wiper mode) for controlling the rotation of the motor 6 in the left-right direction, and the position sensor 2 based on the vehicle body position when the maximum reception signal level is obtained by the initial acquisition control.
Position control (continuous tracking mode) in which the plane antenna 10 and the beam reflector 16 are rotationally controlled in the left-right direction in order to set the planar antenna 10 and the beam reflector 16 at fixed positions (horizontal and elevation directions) in accordance with a change in the position signal supplied from 0. Is repeated.
In this case, the number of drive pulses of the motors 21 and 22 is proportional to the rotation angles of the planar antenna 10 and the beam reflection plate 16, and the motor drive pulses of an angle corresponding to a change in the position signal from the position sensor 20 are generated. It is supplied to the motor drivers 25 and 26 as the motor drive control signal.

Next, the operation of the above embodiment will be described. When the device power supply 27 is turned on, the level of the received signal supplied from the distributor 18 to the controller 19 is sampled, and it is determined whether or not the level is lower than a predetermined level Lth.

Here, when the controller 19 determines that the received signal level is lower than the predetermined level Lth,
The initial capture control (wiper mode) is activated, motor drive control signals are output to the motor drivers 25 and 26, the motors 21 and 22 are driven, and the flat antenna 10
3 and the antenna rotating frame 15a, and is driven to rotate to the right or left.
4 and is driven to rotate to the right or left via the reflector rotating frame 15b.

At this time, when the antenna beam reflected by the beam reflector 16 is directed to the direction of the radio wave arriving from the satellite, the received signal level becomes the maximum level. 10 and the beam reflector 16 are driven to rotate in the left-right direction. As described above, the horizontal antenna and the elevation angle can be tracked by controlling the rotation of the planar antenna 10 and the planar beam reflector 16 in which the antenna beam has a tilt angle in the horizontal direction. For example, the tilt angle of the planar antenna 10 is 10 °
Then, the elevation angle direction can be ± 10 ° and the horizontal direction can be 360 °, and the details will be described later.

When the level of the received signal supplied to the controller 19 becomes maximum, the output of the motor drive control signal is stopped, and the plane antenna 10 and the beam reflector 16 change the reflected beam in the direction of the incoming radio wave from the satellite. , And the control mode of the controller 19 is switched from the initial capture control (wiper mode) to the position control (continuous tracking mode).

That is, when the maximum received signal level is obtained, that is, when the position control (continuous tracking mode) is switched, the position signal supplied from the position sensor 20 is used as a reference, Based on a change in the position signal supplied in accordance with the position change, a pulse signal corresponding to the position change is used as a motor drive control signal as a motor drive 25,
26, so that the direction of the antenna beam reflected by the beam reflector 16 from the planar antenna 11 is maintained in the arrival direction of the satellite radio wave at which the maximum received signal level is obtained. Become.

FIG. 2 is a diagram showing a coordinate system of the planar antenna 10, in which the center point of the antenna opening surface is defined as the origin O. Also, x
The axis and the y axis are on the same plane as the antenna aperture surface, and the z axis is the same direction as the antenna beam as the positive direction. FIG. 3 is a diagram showing a beam reflected by the reflector 16 in the case where the reflector 16 is flat.

Next, a description will be given of the tracking angles in the horizontal and elevation directions by the horizontal rotation driving of the planar antenna 10 and the planar beam reflector 16. 2 and FIG. 3, A: the antenna beam unit vector B: Beam unit vector C ₁ from the reflection plate 16: reflector 16 in the same direction unit vector C _2: vertical unit vector C ₃ of the reflector 16: reflector 16 vertical unit vectors (C ₂ × C
₁₎ .theta.a: antenna beam tilt angle with respect to the z-axis .phi.a: antenna beam angle theta _B relative to the x-axis: the beam angle from the reflection plate 16 with respect to the z-axis phi _B: beam angle θr from the reflection plate 16 with respect to x-axis: for z-axis The angle φr of the reflecting plate 16: the angle of the reflecting plate 16 with respect to the x-axis ix, iy, iz: the unit vectors of the x-, y-, and z-axes, respectively, are as follows.

A = sin θa cos φa ix + sin θa sin φa iy + cos θa iz C ₁ = sin θr cos φr ix + sin θr sin φr iy + cos θr iz C ₂ = cos θr cos φr ix −cos θr sin _{iz C 3 = C 2 × C} 1 = -sin φr ix + cos φr iy B = sin θ B cos φ B ix + sin θ B sin φ B iy + cos θ B iz B = (A · C 1) C 1 - (A _{· C 2) C 2 + (} A · C 3) C 3 ∴sin θ B cos φ B ix + sin θ B sin φ B iy + cos θ B iz = [{cos θa sin 2θr -sin θa cos 2θr cos (φa - φr)｝ ・ cos φr + sin θa sin (φa -φr) sin φr] ix + [scos θa sin 2θr -sin θa cos 2θr cos (φa -φr)｝ ・ sin φr -sin θa sin (φa -φr) cos φr] iy + ｛cos θa cos 2θr + sin θa sin 2θr cos (φa−φr)｝ iz Therefore, the beam angles θ _B and φ _B from the reflection plate 16 are obtained as follows.

[0025] ^{_{θ B = cos -1 (cosθa cos}} 2θr + sin θa sin 2θr cos (φa -φr)) φ B = tan -1 ((Gsin φr + Hcos φr) / (Gcos φr -Hsin φr)) G = cos θa sin 2θr−sin θa cos 2θr cos (φa−φr) H = sin θa sin (φa−φr) Since the planar antenna 10 and the reflecting plate 16 are each rotatable with respect to the Z axis, the antenna beam angle φa
And the reflector angle φr can be selected to any value between 0 ° and 360 °. Accordingly, the maximum value θ _Bmax and the minimum value θ _Bmin of the beam angle θ _B from the reflection plate 16 are obtained as follows.

[0026] _{θ Bmax = 2θr + θa (φa} = π + φr) θ Bmin = 2θr -θa from (φa = φr) This beam angle from satellite reflector 16 theta
It can be seen that allows tracking when in range of _bmax through? _Bmin.

[0027] When placing the planar antenna 10 horizontally, when the satellite elevation angle and theta _EL, beam angle from the reflection plate 16 theta
The relationship with _B is as follows. θ _EL = π / 2-θ From the above _B, for example, in a state of placing the planar antenna 10 horizontally, when obtaining the tracking range of the time around the Tokyo (BS satellite elevation angle approximately 38 °), z-axis Θr = 26 °, and when the tilt angle θa = 10 °, _θBmax = 62 ° and _θBmin = 42 °. Therefore, the satellite elevation angle θ _EL can be tracked between 28 ° and 48 °, and can be used in the range from Hokkaido to Kyushu.

Although the tracking range in the elevation direction increases as the tilt angle of the planar antenna 10 increases, the antenna gain decreases, and the antenna must be enlarged.
In addition, since the moving body itself tilts, there is a need for a margin in the tracking range in the elevation direction (4% tilt at 7% gradient). Therefore, the elevation angle adjusting mechanism 17 is provided so that the reflection plate angle θr can be changed, and tracking in the elevation angle direction can be performed within a practical range, and the tracking range can be changed by adjusting the elevation angle adjusting mechanism 17 in a range larger than that. For example, in the case from Hokkaido to Kyushu, a tilt angle θa = 14 ° is required when adding the inclination of the moving object itself ± 4 °. However, since the elevation angle of the satellite in most of Honshu is in the range of 33 ° to 43 °, even in the range of 29 ° to 47 ° in which the inclination of the moving object itself is added ± 4 °, the tilt angle that can be tracked is θa = 9 ° is enough. At this time, the reflection plate angle θr = 26 °. In addition, the reflector 16 can be folded and stored compactly when not in use by the elevation angle adjusting mechanism 17.

As described above, it is possible to achieve a small-sized, light-weight, and low-cost satellite receiving automatic tracking antenna apparatus that can be easily spread to the general public. In addition, at the time of initial acquisition of the satellite or re-acquisition after moving in the tunnel, it is necessary to operate in all horizontal directions and all elevation directions, and it takes time to acquire. In addition, since it cannot be determined whether the vehicle is inside or outside the tunnel, the control is performed such that a re-capture operation is performed, for example, every 10 seconds, and the useless re-capture operation must be continued until the user leaves the tunnel. As a solution to this, for example, a position sensor 20 including a GPS device, an inclinometer,
By connecting to the CPU, the approximate position of the satellite with respect to the antenna device is calculated by the CPU, and the time required for initial acquisition of the satellite and reacquisition after moving in the tunnel can be reduced. Further, it is possible to determine whether there is an obstruction in the tunnel or between the satellite and the satellite based on the presence or absence of the GPS wave, so that the unnecessary operation of re-capturing in the tunnel is not performed.

[0030]

As described above in detail, according to the present invention, the beam tilt plane antenna and the beam reflector are controlled to rotate in the horizontal direction to track the radio wave from the satellite. The driving means enables tracking in both the horizontal and elevation directions, and can be reduced in size, weight, and cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an automatic tracking antenna device for satellite reception according to an embodiment of the present invention.

FIG. 2 is a diagram showing a coordinate system of the antenna in the embodiment.

FIG. 3 is a diagram showing a state where an antenna beam is reflected by a reflector in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Planar antenna 11 High frequency rotation coupler 12 Low noise block converter (LNB) 13 Fixed base 14a, 14b Rotation mechanism part 15a Antenna rotation frame 15b Reflector rotation frame 16 Beam reflection plate 17 Elevation angle adjustment mechanism 18 Distributor 19 Controller 20 Position sensor 21 Antenna motor (M) 22 Reflector motor (M) 23, 24 Roller 25, 26 Motor driver 27 Power supply

Claims (2)

(57) [Claims] 1. An antenna having an antenna beam having a preset tilt angle, antenna rotation fixing means for arranging the antenna so as to be rotatable with respect to an axis perpendicular to the antenna surface, and disposing the antenna on a movable body fixing portion, Antenna rotation driving means for rotating and driving the antenna in the body fixing portion; a beam reflector for reflecting the beam of the antenna in the direction of the satellite; and a beam reflector which can be freely rotated in the horizontal direction and is arranged on the movable body fixing portion. Reflector rotating and fixing means, reflector rotating driving means for rotating and driving the beam reflector in the moving body fixing section, antenna rotating driving means and reflector rotating driving means in accordance with a signal level received from the antenna Control means for controlling the rotation of the automatic tracking antenna device for satellite reception. 2. A displacement detecting means for detecting at least one displacement of the moving body fixing part in the horizontal direction and the elevation angle direction, the antenna rotation driving means and the reflecting plate according to the displacement of the moving body fixing part by the displacement detecting means. 2. The automatic tracking antenna device for satellite reception according to claim 1, further comprising: displacement control means for controlling rotation of the rotation driving means.