JPH06326509A - Automatic tracking antenna device for reception of satellite - Google Patents

Abstract

PURPOSE:To provide a compact, light-weight and inexpensive antenna device which can track a satellite in both horizontal and elevation direction by means of only a horizontal rotary driving means. CONSTITUTION:A beam tilt plane antenna 10 and a beam reflecting plate 16 are rotatably set to a round fixed base 13 via the rotary frames 15a and 15b. A controller 19 drives the motors 21 and 22 in response to the level of the reception signal sent from the antenna 10 via a low noise block converter 12 and turns the antenna 10 and the plate 16 via both frames 15a and 15b to acquire the highest level of the reception signal. Thereafter the controller 19 controls the drive of both motors 21 and 22 based on the azimuth signal supplied from a position sensor 20 and also based on the change of the azimuth signal supplied in accordance with the azimuthal variance of a vehicle body and holds a plane antenna 11 and the plate 16 in the arriving direction of the satellite radio wave in order to always acquire the highest level of the reception signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite receiving automatic tracking antenna device mounted on a moving body such as a vehicle or a ship.

[0002]

2. Description of the Related Art Conventionally, a satellite receiving automatic tracking antenna device used by being mounted on a moving body such as a vehicle or a ship is designed to horizontally rotate the beam direction of the antenna as the moving body moves in the left-right direction. It has a direction rotation tracking mechanism and an elevation angle tracking mechanism that displaces the beam direction of the antenna to the elevation angle direction when the moving body tilts up and down, and the antenna itself converts the elevation angle tracking mechanism and its received signal into frequency. Noise block converter (LNB)
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 portion side and a DC coupler for transmitting a power source and a control signal for elevation angle tracking to the rotary portion side are required.

[0004]

In the conventional automatic tracking antenna device described above, a pair of pairs of a horizontal rotation tracking mechanism operates in response to a horizontal displacement and an elevation angle tracking mechanism operates in response to an elevation angle displacement. Since it corresponds to No. 1, there is a problem that both the rotary system and the coupling system are complicated, heavy and large in size, and it is difficult to reduce the size, the weight, and the price, which are generally popular.

The present invention has been made in view of the above circumstances, and satellite tracking automatic tracking antenna apparatus capable of tracking in both horizontal and elevation directions by means of two horizontal rotation driving means and capable of achieving small size, light weight and low cost. The purpose is to provide.

[0006]

An automatic tracking antenna device for satellite reception according to the present invention includes an antenna having an antenna beam having a preset tilt angle, and the antenna being rotatable about an axis perpendicular to the antenna surface. An antenna rotation fixing means to be placed on the moving body fixing portion, an antenna rotation driving means for rotating and driving the antenna in the moving body fixing portion, a beam reflector for reflecting the beam of the antenna in the satellite direction, and this beam Reflector rotation fixing means for arranging the reflection plate in the horizontal direction in the moving body fixing portion, reflecting plate rotation driving means for rotating the beam reflecting plate in the moving body fixing portion, and Control means for controlling rotation of the antenna rotation driving means and the reflector rotation driving means according to the received signal level. .

[0007]

With the antenna beam having a preset tilt angle and the beam reflector being rotatable in the horizontal direction, it is possible to perform tracking in both the horizontal and elevation directions only by the rotation driving means in the horizontal direction. 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 can be simplified, and the size, weight, and cost can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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, and this automatic tracking antenna device is provided with a beam tilt plane antenna 10.

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

Low Noise Block Converter (LNB)
Reference numeral 12 is an intermediate frequency band in which a high frequency circuit board (SHF) and an intermediate frequency circuit board (IF) are built in, and satellite reception signals supplied from the planar antenna 10 through the high frequency rotary coupler 11 are made to correspond to receiver inputs. Convert to and amplify. The planar antenna 10 and the low noise block converter (LN
B) 12, mounted 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 thereof. The rising portions 13a and 13b have a rotating mechanism portion 14a having a ball bearing built therein. An annular antenna rotation frame 15a and a reflector rotation frame 15b are provided via 14b. Then, the flat antenna 10 is mounted on the antenna rotating frame 15a, and one end of the flat beam reflecting plate 16 which is sufficiently larger than the radiation plate surface of the flat antenna 10 is located 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 in elevation angle by the elevation angle adjustment mechanism 17 so that the antenna beam of the planar antenna 10 is reflected in the elevation angle direction corresponding to the arrival direction of satellite radio waves.

The low noise block converter (LN
B) The reception signal converted into the intermediate frequency band by 12 is supplied to the receiver through the distributor 18 (IF output), and the other is converted into a DC signal according to the reception signal level for control. Is supplied to the container 19.

Further, this automatic tracking antenna device is provided with a position sensor 20 using a displacement detecting means such as a GPS device or an azimuth detector for detecting the displacement of the moving body in the horizontal direction, the elevation angle direction or both directions. A position signal according to the displacement of the body is supplied to the controller 19.

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

As described above, the two horizontal rotation driving means for the plane antenna 10 and the plane beam reflector 16 track the satellite in both the horizontal and elevation directions.
Further, for example, an on-vehicle DC power supply is input to the power supply circuit 27 and distributed and supplied to each part of the control system and the drive system.

The controller 19 has a program-controlled CPU (macro processor), and when the received signal level supplied from the distributor 18 is below a predetermined level Lth at which it can be sufficiently received as a video signal, the reception is performed. Planar antenna 10 and beam reflector 1 so that the signal level is maximized
An initial acquisition control (wiper mode) for controlling rotation of 6 in the left-right direction, and a position sensor 2 based on the vehicle body position when the maximum reception signal level is obtained by this initial acquisition control.
Position control (continuous tracking mode) in which the plane antenna 10 and the beam reflector 16 are controlled to rotate in the left-right direction in order to set the flat antenna 10 and the beam reflector 16 at constant positions (horizontal direction and elevation angle direction) according to changes in the position signal supplied from 0; Is repeatedly controlled.
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 reflector 16, and the motor drive pulses for the angle corresponding to the change amount of the position signal from the position sensor 20 are generated. The motor drive control signal is supplied to the motor drivers 25 and 26.

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 the received signal level is equal to or lower than a preset predetermined level Lth.

When the controller 19 determines that the received signal level is below the predetermined level Lth,
The initial capture control (wiper mode) is activated, a motor drive control signal is output to the motor drivers 25 and 26, the motors 21 and 22 are driven, and the planar antenna 10 causes the roller 2 to move.
3 and the antenna rotation frame 15a, the beam is rotated rightward or leftward, and the beam reflector 16 is rotated by the roller 2
It is rotationally driven in the right or left direction via the 4 and the reflector rotating frame 15b.

At this time, when the antenna beam reflected by the beam reflector 16 is directed in the direction of the incoming radio wave from the satellite, the received signal level becomes the maximum level. Therefore, the planar antenna is obtained until the maximum received signal level is obtained. 10 and the beam reflector 16 are rotationally driven in the left-right direction. As described above, the plane antenna 10 having the tilt angle of the antenna beam and the plane beam reflector 16 are controlled to rotate in the horizontal direction, so that tracking can be performed in both the horizontal direction and the elevation angle. For example, the tilt angle of the planar antenna 10 is 10 °
In this case, the elevation angle can be ± 10 ° and the horizontal direction can be 360 °, which will be described in detail 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 direct the reflected beam to the incoming radio wave direction from the satellite. 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 to, the position signal supplied from the position sensor 20 is used as a reference, and the vehicle body after that is used as a reference. Based on the change in the position signal supplied with the position change, the pulse signal corresponding to the position change is used as the motor drive control signal by the motor driver 25,
26, so that the direction of the antenna beam reflected from the plane antenna 11 by the beam reflector 16 is maintained in the direction of arrival of the satellite radio wave in which the maximum received signal level is obtained. Become.

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

Next, the trackable angles in the horizontal and elevation angles by the horizontal rotation drive of the planar antenna 10 and the planar beam reflector 16 will be described. 2 and 3, A: antenna beam unit vector B: beam unit vector from the reflector 16 C ₁ : unit vector in the same direction as the reflector 16 C ₂ : vertical unit vector of the reflector 16 C ₃ : reflector 16 vertical unit vectors (C ₂ × C
₁ ) θa: Antenna beam tilt angle with respect to z-axis φa: Antenna beam angle with respect to x-axis θ _B : Beam angle from reflector 16 with respect to z-axis φ _B : Beam angle from reflector 16 with respect to x-axis θr: With respect to z-axis Angle φr of reflector 16: Angle of reflector 16 with respect to x-axis ix, iy, iz: If x, y, and z-axis are unit vectors, their relations are as follows.

A = sin θa cos φa ix + sin θa sin φa ii + cos θa iz C ₁ = sin θr cos φr ix + sin θr sin φr ii + cos θr iz C ₂ = cos θr cos φr ix + cos θr sin φr ii −sin θ 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 2 θr −sin θa cos 2 θr cos (φa − φr)} ・ cos φr + sin θa sin (φa −φr) sin φr] ix + [{cos θa sin 2θr −sin θa cos 2θr cos (φa −φr)} ・ sin φr −sin θa sin (φa −φr) cos [phi] r] iy + {cos [theta] a cos 2 [theta] r + sin [theta] a sin 2 [theta] r cos ([phi] a- [phi] r)} iz Therefore, the beam angles [theta] _B and [phi] _B from the reflector 16 are obtained as follows, respectively.

Θ _B = cos ⁻¹ (cos θa cos 2 θr + sin θa sin 2 θr 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 reflector 16 are each rotatable with respect to the Z axis, the antenna beam angle φa
The reflector angle φr can be selected to any value between 0 ° and 360 °. Therefore, the maximum value θ _Bmax and the minimum value θ _Bmin of the beam angle θ _B from the reflecting plate 16 are obtained as follows.

Θ _Bmax = 2θ r + θa (φa = φr) θ _Bmin = 2 θr −θa (φa = π + φr) From this, the satellite detects the beam angle θ from the reflector 16.
It can be seen that allows tracking when in range of _bmax through? _Bmin.

When the plane antenna 10 is placed horizontally, and the satellite elevation angle is θ _EL , the beam angle θ from the reflector 16 is θ.
The relationship with _B is as follows. Since θ _EL = π / 2−θ _B or more, for example, when the planar antenna 10 is placed horizontally, the trackable range around the Tokyo (BS satellite elevation angle of about 38 °) is obtained. With respect to the reflector angle 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 the satellite can be used in the range from Hokkaido to Kyushu.

It should be noted that the larger the tilt angle of the planar antenna 10, the wider the tracking range in the elevation direction, but the antenna gain decreases, so the antenna must be made larger.
Further, due to the inclination of the moving body itself, it is necessary to have a margin in the tracking range in the elevation direction (inclination of 4 ° at a 7% gradient). Therefore, the elevation angle adjusting mechanism 17 is provided so that the reflector angle θr can be changed, and tracking in the elevation angle direction is performed within a practical range. For the range beyond that, the tracking possible range is changed by adjusting the elevation angle adjusting mechanism 17. For example, in the case of from Hokkaido to Kyushu, if the tilt of the moving body itself is added by ± 4 °, the tilt angle θa = 14 ° is required. However, in most of Honshu, the satellite elevation angle is in the range of 33 ° to 43 °, so the tilt angle that can be tracked is θa = even in the elevation angle range of 29 ° to 47 ° in which the inclination of the moving body itself is ± 4 °. 9 ° is enough. At this time, the reflection plate angle θr = 26 °. Further, the elevation angle adjusting mechanism 17 allows the reflector 16 to be folded and stored compactly when not in use.

As described above, it is possible to achieve a small-sized, light-weight, low-priced satellite tracking automatic tracking antenna device which can be easily spread to the general public. Note that it is necessary to operate in all horizontal directions and all elevation angles at the time of initial acquisition of the satellite or reacquisition after moving in the tunnel, and it takes time to acquire. Further, since it is not possible to determine whether it is inside or outside the tunnel, the control is performed such that the reacquisition operation is performed every 10 seconds, for example, and the wasteful reacquisition operation must be continued until the vehicle exits the tunnel. As a solution to this, for example, a position sensor 20 including a GPS device, an inclinometer, and an azimuth meter is used as a controller 19
By connecting with, the approximate position of the satellite with respect to the antenna device can be calculated by the CPU, and the acquisition time at the time of initial acquisition of the satellite and reacquisition after moving in the tunnel can be shortened. Further, when there is a shield in the tunnel or between the satellite and satellites, it can be discriminated by the presence or absence of GPS waves, and the extra operation of reacquisition in the tunnel does not occur.

[0030]

As described above in detail, according to the present invention, since the beam tilt plane antenna and the beam reflector are rotationally controlled in the horizontal direction to track the radio waves from the satellite, two horizontal rotations are performed. The driving means enables tracking in both horizontal and elevation directions, and can achieve size reduction, weight reduction, and cost reduction.

[Brief description of drawings]

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

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

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

[Explanation 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

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[Procedure amendment]

[Submission date] June 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

Θ _Bmax = 2θr + θa ( φa = π + φr ) θ _Bmin = 2θr −θa ( φa = φr ) From this, the satellite detects the beam angle θ from the reflector 16.
It can be seen that allows tracking when in range of _bmax through? _Bmin.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (2)

[Claims] 1. An antenna having an antenna beam having a preset tilt angle; antenna rotation fixing means for rotatably disposing this antenna on an axis perpendicular to an antenna surface and arranging it on a movable body fixing portion; Antenna rotation driving means for rotatably driving the antenna in the body fixing portion, a beam reflecting plate for reflecting the beam of the antenna in the satellite direction, and the beam reflecting plate rotatably in the horizontal direction and arranged in the moving body fixing portion. Rotating means for rotating the reflecting plate, rotating means for rotating the rotating plate of the beam in the fixed portion of the moving body, and rotating means for rotating the antenna and rotating means for rotating the reflecting plate according to the received signal level from the antenna. An automatic tracking antenna device for satellite reception, comprising: 2. A displacement detecting means for detecting at least one displacement of a moving body fixing portion in a horizontal direction and an elevation angle direction, and the antenna rotation driving means and a reflector according to the displacement of the moving body fixing portion by the displacement detecting means. 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.