JPH1084213A - Antenna tracking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the fast and stable tracking and also to reduce the wear and fatigue of every component parts, the energy consumption and the operating noises respectively in drive mode by controlling the drive of an oscillation means according to the revolving state of a mobile object. SOLUTION: A mobile object operation detection part 32 inputs the receiving level sent from a C/N (carrier/noise) detection part 31 and also calculates the revolving direction and speed of a mobile object based on the operation (control) information on a motor 4 that is given from a drive control part 33. The part 33 fetches the receiving level sent from the part 31 and controls the motor 4 via a drive control line 43 to turn an antenna 2 toward a satellite by a step track system and also fetches the information on the revolving direction and speed on the mobile object from the part 32 and controls the motor 4 via the line 43 to quickly turn the antenna 2 toward the satellite despite a direction change or the mobile object. In otner words, the fight (left) revolving speed is increased when the right (left) oscillation time is long, so that the revolving speed of the mobile object is kept constant to the satellite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking device for an antenna mounted on a moving body such as an automobile, and more particularly to a tracking device for an antenna for controlling the direction of the antenna so as to always face a broadcasting satellite.

[0002]

2. Description of the Related Art FIG. 15 is a schematic block diagram showing a conventional antenna tracking control device. Note that components having the same function are denoted by the same reference numerals throughout the drawings.
As shown in the figure, an antenna 2 mounted on a mobile unit that receives broadcast radio waves from a satellite 1 includes an antenna main unit 21 composed of elements for receiving radio waves, and an antenna main unit 21.
Is fixed thereon, and a turntable 22 for rotating the antenna body 21 so that the direction of the antenna (directivity) is directed toward the satellite 1, and a down converter for converting the frequency of a signal received by the antenna body 21 25. The turntable 22 includes a driving unit 4 composed of a motor or the like for rotating the turntable 22 and a turntable 22 for rotating the turntable 22.
And a rotary joint unit 5 for outputting a signal received by the antenna main body unit 21 to a satellite broadcast receiver provided in the vehicle interior. The tracking control unit 3 takes in the received signal from the rotary joint unit 5, forms a signal for controlling the driving of the turntable driving unit 4, and outputs a control signal to the turntable driving unit 4. The tracking control unit 3 receives a received signal via an A / D converter (Analog Digital Converter) (not shown) and, based on the level of the input signal, a central processing unit (CPU) (not shown). ) To perform tracking processing.

An antenna tracking control section 3 performs tracking by rotating an antenna body section 21 in a horizontal plane in order to receive a radio wave from the satellite 1. As a main method, a step track tracking method described below is used. Is often adopted. FIG.
FIG. 6 is a schematic diagram for explaining a conventional step track tracking method. As shown in FIG. 16, an antenna 2 mounted on a mobile body that receives broadcast radio waves from a satellite swings right and left at a certain range of angles around a certain direction θ ₃ (centering direction of swing). And measure the reception level at the time of swinging motion,
The reception levels in the left and right directions in the swing operation are compared, and the center of the swing is moved to the higher reception levels θ ₂ and θ ₁ . By repeating this, the direction of the antenna 2 gradually approaches the direction θ _{0 at} which the peak value of the reception level is obtained. Although this step track tracking method can be realized at a low cost with a simple device configuration, there is a problem in that tracking performance (direction followability) is low. The reason is as follows.

In the step track tracking method, the antenna 2 is always swung near the direction of the satellite, the state of the reception level is detected, and the direction of the satellite is estimated. In such a trial-and-error tracking method, it is easy to remove the tracking when a sudden change in the direction of the moving object or radio wave shielding occurs. In other words, if the direction of the satellite, that is, the direction of the reception peak goes out of the swing range due to a sudden change in the direction of the moving object, the center of the swing will not be the direction of the satellite in one swing. It is only possible to gradually approach the direction of the antenna 2 to the direction of the satellite by repeating the turn or swing, and in the worst case, it is difficult to detect which side of the left or right of the center of the swing is the satellite. Become.

[0005]

As a method of solving this problem, there is a method in which control using the rotation direction and speed data of a moving body is added to the above-described step track tracking method. For example, an angular velocity sensor such as a gyro sensor for detecting an angular acceleration is mounted on a moving body, and a rotation direction and a speed of the moving body are obtained based on a signal from the angular velocity sensor. And
The tracking control unit 3 to which the received signal from the antenna 2 and the rotation direction and speed signal of the moving object are input, calculates the rotation direction and amount of the moving object from the signal from the angular velocity sensor when the direction of the moving object changes rapidly. The step track control is performed by changing the direction and amount of rotation of the moving body obtained by calculating the direction of the swing center in the swing control. Accordingly, the direction of the satellite is always included in the swing range, and the speed at which the antenna 2 is directed in the direction of the satellite increases, and the tracking performance of the satellite increases. However, since this method uses an angular velocity sensor such as a gyro sensor, there is a problem that the cost increases.

The conventional tracking antenna 2 usually performs a wide-range (wide-angle) mechanical search when it is impossible to detect the direction of arrival of the radio wave (the direction of the satellite). , Or by rotating the antenna 2 360 ° or infinitely. In general, the mechanical search is often performed at a relatively high speed in order to reduce the undetectable time at that time. In addition, even when long-time shielding of radio waves or the like occurs, the above-described high-speed mechanical search is performed although it is actually useless. As described above, when the high-speed search is performed for a long time, there is a problem that movable parts such as a driving part and a driving contact part such as a bearing are quickly worn out, fatigued, and the like. There is also a problem that the energy (electric power) consumed is increased due to the high-speed driving. further,
When high-speed driving is performed, operation noise increases, and a problem of noise also occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides an antenna tracking capable of performing high-speed and stable tracking and reducing wear and fatigue of each component during driving, energy consumption, and operation noise. It is intended to provide a device.

[0008]

In order to achieve the above object, an antenna tracking device (1) according to the present invention is arranged such that the direction of an antenna provided on a mobile body for receiving a broadcast wave from a satellite is adjusted. In a tracking control device for an antenna for tracking so as to face a direction of a satellite, a swinging operation for performing a swinging operation of shifting the direction of the antenna over a predetermined angle from side to side so that the direction of the satellite is the center of the swinging. Means, an antenna control means for controlling the direction of the antenna by changing the center of the oscillation according to the state of the received signal during the oscillation operation, and a rotation speed storage means for storing the rotation speed of the oscillation operation A rotation speed control unit that drives and controls the oscillating unit according to the rotation speed stored in the rotation speed storage unit;
Rotation state detection means for detecting the rotation state of the moving body in accordance with the reception state of the broadcast radio wave during the swinging operation, and the rotation in accordance with the rotation state of the moving body detected by the rotation state detection means A rotation speed calculating unit configured to increase or decrease the rotation speed stored in the speed storage unit by a predetermined amount.

An antenna tracking device (2) according to the present invention tracks an antenna provided on a moving body for receiving a broadcast wave from a satellite so as to face the satellite. In the control device, a oscillating means for performing an oscillating operation of shifting the direction of the antenna over a predetermined angle to the left and right so that the direction of the satellite is the oscillating center, and a reception signal during the oscillating operation. Antenna control means for controlling the direction of the antenna by changing the oscillating center in accordance with a state; rotating speed storing means for storing the rotating speed of the oscillating operation; and rotating speed stored in the rotating speed storing means. Rotation speed control means for driving and controlling the oscillating means in accordance with, and moving body rotation speed detecting means for detecting the rotating speed of the moving body in accordance with the reception state of broadcast radio waves during the oscillating operation; A rotation speed for newly storing the rotation speed obtained by adding the added rotation speed according to the rotation speed of the moving body detected by the moving body rotation speed detection unit and the rotation speed of the moving body in the rotation speed storage unit; And rotation speed setting means for setting the rotation speed.

[0010] An antenna tracking device (3) according to the present invention tracks an antenna provided on a mobile body for receiving a broadcast wave from a satellite so as to face the satellite. In the control device, a oscillating means for performing an oscillating operation of shifting the direction of the antenna over a predetermined angle to the left and right so that the direction of the satellite is the oscillating center, and a reception signal during the oscillating operation. Antenna control means for controlling the direction of the antenna by changing the oscillating center in accordance with a state; rotating speed storing means for storing the rotating speed of the oscillating operation; and rotating speed stored in the rotating speed storing means. A rotational speed control means for drivingly controlling the oscillating means in accordance with the rotational speed; and a moving body rotational acceleration detecting means for detecting a rotational acceleration of the moving body in accordance with a broadcast radio wave reception state during the oscillating operation. And a rotation speed obtained by adding the added rotation speed according to the rotation acceleration of the moving body detected by the moving body rotation acceleration detection unit and the rotation speed of the moving body to the rotation speed storage unit. Rotation speed setting means for setting the rotation speed.

Further, in the antenna tracking device (4) according to the present invention, in the antenna tracking device (1), the rotation state detecting means determines a time between a point in time when the received signal level becomes a predetermined level during the swing operation. It is characterized in that it detects the rotational state of the moving body.

Also, in the antenna tracking device (5) according to the present invention, in the antenna tracking device (1), the rotation state detecting means may detect a signal level during a time when the received signal level becomes a predetermined level during the swing operation. The rotation state of the moving object is detected by the integrated value of

Further, in the antenna tracking device (6) according to the present invention, in the antenna tracking device (1), the rotation state detecting means may determine that the rotation level detecting means has a predetermined level during a time when the received signal level becomes a predetermined level during the swing operation. The rotational state of the moving object is detected based on the amount of change (differential value) of the received signal level at the step (1).

An antenna tracking device (7) according to the present invention tracks an antenna provided on a moving body for receiving a broadcast wave from a satellite so as to face the satellite. In the control device, a oscillating means for performing an oscillating operation of shifting the direction of the antenna over a predetermined angle to the left and right so that the direction of the satellite is the oscillating center, and a reception signal during the oscillating operation. Antenna control means for controlling the direction of the antenna by changing the center of the swing according to the state, and comparing the received signal level with a predetermined comparison level during the swing operation, and the received signal level becomes the comparison level. And an inverting means for outputting an inversion signal for inverting the direction of movement of the antenna to the oscillating means, and the comparison level is reduced for a predetermined period after the inversion of the antenna. It is characterized in that it comprises a compare level reducing means.

The antenna tracking device (8) according to the present invention, in any one of the antenna tracking devices (1) to (3), compares a received signal level with a predetermined comparison level during a swing operation. Inverting means for outputting an inverted signal for inverting the direction of movement of the antenna to the oscillating means when the received signal level becomes the comparison level, and for a predetermined period after the inversion of the antenna, lowering the comparison level. And a comparing level lowering means.

The antenna tracking device (9) according to the present invention is characterized in that the predetermined period in the antenna tracking device (7) or the antenna tracking device (8) is a fixed time.

The antenna tracking device (1) according to the present invention
0) is characterized in that the predetermined period in the antenna tracking device (7) or the antenna tracking device (8) is a period in which the received signal level exceeds a return level higher than the comparison level.

The antenna tracking device (1) according to the present invention
1) In any one of the antenna tracking devices (1) to (3), maximum value storage means for storing a maximum value of a received signal level in a swing operation, a received signal level in a swing operation and the maximum value. An abnormality detecting means for calculating a difference between the maximum value stored in the value storage means and determining that the reception is abnormal when the level difference is equal to or more than a predetermined value; and A change prohibition unit for prohibiting a change of the swing center is provided.

The antenna tracking device (1) according to the present invention
2) The antenna tracking device (11) includes a maintenance unit that maintains the rotational speed stored in the rotational speed storage unit when the abnormal state is detected by the abnormal state detection unit in the antenna tracking device, and receives the signal when the abnormal reception state is released. It is characterized in that tracking control of the antenna is performed under conditions before abnormality detection.

The antenna tracking device (1) according to the present invention
3) is provided with an exploration range enlarging means for widening the swing angle in the swing operation when the detection of abnormal reception by the abnormality detecting means in the antenna tracking device (12) continues for a predetermined time or more. It is characterized by:

The antenna tracking device (1) according to the present invention
4) In the antenna tracking device (13), when the swing range is widened by the search range expanding means in the antenna tracking device (13), a swing speed reducing means for reducing the swing speed in the swing operation is provided. Features.

Further, the antenna tracking device (1) according to the present invention
5) In any one of the antenna tracking devices (1) to (3), a non-rotational state detecting means for detecting that the rotational speed of the moving body is 0, and the moving body by the non-rotating state detecting means. And stopping means for stopping the antenna at the center of the swing when it is detected that the rotation speed is zero.

The antenna tracking device (1) according to the present invention
6) In the antenna tracking device (15), the moving body is an automobile, and the non-rotation state detecting means detects that the rotation speed of the automobile is 0 from a signal of a speedometer of the automobile. It is characterized by having.

The antenna tracking device (1) according to the present invention
7) In the antenna tracking device (15), the moving body is an automobile, and the non-rotational state detecting means determines that the difference between the rotational speeds of the left and right wheels of the automobile is 0, Is detected to be 0.

The antenna tracking device (1) according to the present invention
8) In the antenna tracking device (15), the moving body is an automobile, and the non-rotation state detecting means detects that the rotation speed of the automobile is 0 based on a parking brake state of the automobile. It is characterized by having.

The antenna tracking device (1) according to the present invention
9) In the antenna tracking device (15), the moving body is an automobile, and the non-rotational state detecting means detects a rotation speed of the automobile when a shift position of a transmission in the automobile is a neutral or parking position. Is 0
Is detected.

The antenna tracking device (2) according to the present invention
0) In the antenna tracking device (15), the non-rotational state detection means determines that the rotational speed of the moving body is 0 when the state of the received signal level in each of the horizontal swing motions is the same. Is detected.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an antenna tracking device according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of the antenna tracking device according to the embodiment. As shown in FIG. 1, fixed to the moving body,
The antenna base 2 which rotates when the moving body rotates.
An antenna main body 21 is fixed to a turntable 22 rotatably fixed to 3, and the antenna main body 21 can be rotated 360 ° with respect to a moving body. The antenna body 21 is formed of a planar antenna such as a known patch antenna, slot antenna, or helical antenna, and its directivity is constant with respect to a plane.
The elevation direction is a direction substantially coincident with the direction of the satellite in the use area, and has a relatively sharp (narrow) directional characteristic. On the upper surface of the antenna base 23, there is provided a down converter 25 for converting the frequency of the received satellite broadcast wave into a frequency that can be processed by the satellite broadcast receiver. Antenna base 23
A motor 4 for rotating and driving the turntable 22 is provided above. Since there is an angular displacement between the antenna main body 21 and the down converter 25 due to rotation, connection is made by a connection mechanism (rotary joint part 5) having a relatively marginal signal line or a contact having a rotatable slip ring or the like. Have been.

The tuner 10 of the satellite broadcast receiver is connected to the down converter 25 via a reception signal line 41. The tuner 10 demodulates a satellite broadcast wave and outputs a video signal and an audio signal.
And a tracking control unit 3 for controlling the direction of the camera 1. The tracking control unit 3 is connected to the power supply unit 30 that supplies power to the motor 4 via the power supply line 42, is connected to the antenna main unit 21 (down converter 25) via the reception signal line 41, and has a large carrier and noise level. / N to detect the reception level based on the
(Carrier-to-noise ratio) A reception level from the detection unit 31 and the reception level from the C / N detection unit 31 are input, and the rotation direction and speed of the moving body are determined from operation (control) information of the motor 4 from the drive control unit 33. The moving body motion detection unit 32 to be calculated and the C / N detection unit 3
1 is received so that the antenna 2 faces the satellite by the step track method, and information on the rotation direction and speed of the moving body is taken from the moving body operation detection unit 32, and the antenna 2 is changed even if the direction of the moving body changes. Has a drive control unit 33 that supplies a signal for controlling the motor 4 to the motor 4 via the drive control line 43 so as to quickly turn to the direction of the satellite. Note that the drive control unit 33 and the moving body operation detection unit 32 are configured by a microcomputer (microcomputer) 34.

Further, various signals indicating the state of the vehicle are input to the drive control unit 33 from various control devices of the vehicle, the engine control device, the transmission control device and the like. These signals include a signal indicating a transmission state (neutral, parking), a signal indicating a speed given to a speedometer or the like, a signal indicating a parking state given to a parking brake display section of a display, a light emitting / receiving element and a magnetic sensing element. And includes a signal from a wheel speed sensor that is provided on left and right wheels (generally non-driven wheels) and outputs a signal corresponding to the rotation speed of the left and right wheels.

The signal flow is as follows: a radio wave from a satellite is received by the antenna main body 21, passes through the rotary joint 5 installed near the center of the turntable 22, passes through the down converter 25, and passes through the C / N detector 31. Detects the reception level. Specifically, a drive signal is sent to the motor 4 so that the antenna main body 21 (turntable 22) is rotated with respect to the antenna base 23 at the same speed as the rotation speed of the moving body in the direction opposite to the rotation direction of the moving body. Given.

The turntable 22 of the antenna 2 is mounted on an antenna base 23. This antenna base 23 is attached to a moving body, and when the moving body rotates,
The antenna base 23 also rotates. Then, as shown in FIG. 2, when the antenna 2 is facing the satellite,
The drive control unit 33 sets this direction to the center (the center of the swing).
As the direction, a swing operation of Δθ (oscillation angle) is performed in each rotation direction around the center direction around the center direction (right swing: + direction, left swing:-direction).

First, a method of detecting the rotational speed of the moving body by the moving body operation detecting section 32 will be described. Since the oscillating speed is for a satellite (geostationary satellite) or the earth, the oscillating speed is as follows. Swing speed = rotation speed of moving object + rotation speed of turntable 22 (1) The rotation speed of turntable 22 is determined by antenna base 23.
That is, the rotation speed with respect to the moving body. When the rotation direction of the turntable 22 is the same as the rotation direction of the moving body, the sign ± of the expression (1) becomes +, and the sign ± becomes − in the opposite case.

FIG. 3 is a graph for explaining a change in reception level near the center direction when there is no rotational movement of the moving body. As shown in FIG. 3, the reception level changes in a chevron with respect to the swinging motion (angle). This swing operation is performed between the left and right swing angles (+ Δθ to −Δθ) where the C / N of the received wave is monitored and the C / N is at a predetermined level. That is, when the C / N falls below the predetermined level, the rotation direction of the turntable 22 is reversed.
By controlling the rotation of the motor 4, the swinging operation is performed. In this way, the swinging operation is performed centering on the satellite direction. Note that the C / N at the time when the turntable 22 is inverted is shown.
The (comparison level) is set to a C / N value that allows good reception, so that a good reception state can always be maintained during the swing operation.

FIGS. 4A to 4D are graphs showing a change over time of the reception level using the swing speed as a parameter when there is no rotational movement of the moving body. 10a in (a)
/ S (second) rotation speed, (b) 20 °
(C) shows a state in a swing operation at a rotation speed of 30 ° / s, and (d) shows a state in a swing operation at a rotation speed of 40 ° / s. The swing motion is
As described above, since the adjustment is performed based on the C / N, the adjustment is performed at a predetermined swing angle (+ Δθ to −Δθ) regardless of the swing speed. Therefore, the reversal interval of the swing motion (swing time Δt)
Is inversely proportional to the swing speed, and the time change of the reception level at each rotation speed is as shown in FIG.

Therefore, the swing speed can be obtained based on the swing time Δt, and the swing speed and the motor 4
The rotation speed of the moving body can be obtained from the rotation speed of the (turntable 22). Similarly, the swing angle (+ Δθ
−−Δθ), the swing speed and the rotation speed of the moving body can be obtained from the area of the reception level between −Δθ). In addition, the swing speed can be obtained based on the inclination of the reception level with respect to time between the swing angles (+ Δθ to −Δθ), and the rotation speed of the moving body can be obtained therefrom. Note that the swing angle needs to be obtained before calculating each rotation speed, and is measured and stored at the time of product manufacture or at the time of design, or when the moving body is stopped (in the case of a car, a speed meter, In this case, a method of detecting and storing the rotation angle of the turntable 22 during the actual swing operation is adopted. The swing time and the rotational speed of the moving body are combined with each other or switched according to the situation, in combination with the swing time, the area of the reception level between the swing angles, and the inclination of the reception level with respect to the time between the swing angles. Can also be requested.

Next, a method of detecting the rotation direction of the moving body will be described. FIGS. 5A and 5B are graphs showing the time change of the reception level when the turntable 22 is swung at 20 ° / s while the moving body is stopped. Since the rotation speed of the moving object is 0 ° / s, the change over time of the reception level during right swing in FIG. 5A and left swing in FIG. 5B is the same. In this case, both the left and right swing speeds are 20 °
/ S.

FIG. 6 is a graph showing the change over time of the reception level when the turntable 22 is swung at 20 ° / s while the moving body is rotating clockwise at 10 ° / s. Since the rotating speed of the moving body is 10 ° / s, the rotating speed of the antenna main body 21 is obtained by adding the rotating speed of the moving body to the swinging speed of the turntable 22 when the right-hand swing of FIG. And the swing speed becomes 30 ° / s. FIG.
In the case of (b) the left swing, the rotation speed of the antenna body 21 is obtained by subtracting the rotation speed of the moving body from the swing speed of the turntable 22, and the swing speed is 10 ° / s.

As described above, when the moving object is stopped,
The time change of the reception level is the same between left and right swing,
When the moving body rotates, the temporal change of the reception level differs between the left and right swings. In the case of swinging in the same direction as the rotation direction of the moving body, the slope of the chevron of the time change of the reception level becomes steeper, and the swinging time becomes shorter. Therefore, from the difference in the swinging time during the swinging operation in the horizontal direction, the rotational direction of the moving body
Speed can be determined.

The direction of rotation of the moving body can be obtained by comparing the areas of the reception levels between the swing angles during the left and right swing operations. Then, the rotation direction of the moving body can be obtained by comparing the inclination of the change in the reception level during the left and right swing operations. Further, the rotation direction of the moving body may be obtained by combining these or switching according to the situation. In this way, the rotation direction and the rotation speed of the moving body can be detected without using expensive components such as a gyro sensor.

FIG. 7 is a graph showing the reception level at the time of the swing operation when the radio wave from the satellite is shielded. As shown in the figure, if the reception level when the head is swung when there is no influence of the radio wave is A and the reception level when the head is swung when there is the influence of the radio wave is B, the radio wave is shielded. The reception level decreases in a short time due to the influence of
The swing motion should be performed during -Δθ.
A swing motion is performed at φ. As a result, originally -Δθ, Δ
The direction of the satellite that should be θ0 at the center between θ is −Δθ, Δ
The center φ0 between φ is detected, and Δθ ~ −
The rotation speed of the moving body for which the swing time is calculated between Δθ is also Δθ
Calculated from the swing time at .DELTA..phi., And the control becomes abnormal.

Therefore, during the swing operation, the peak value V ₀ of the reception level (filtered by moving average processing or the like) is stored, and the peak value V ₀ and the reception level detected during the swing operation are stored. Compare with the peak value V.
In this comparison, it is determined that there is no abnormality only when the difference falls within a certain set value, and control is continued by calculating a control condition such as a swing speed. At other times, it is determined to be abnormal, control under the control conditions up to this point is continued for a predetermined time, and if it returns to a normal state within the predetermined time, the detected rotation state of the moving body is detected and the swing condition is determined. The control returns to the above-described normal state control in which a swing operation is performed. If the normal state is not returned within a predetermined time, a high-speed search operation is performed by 360 ° swing or infinite rotation. In this high-speed search, the reception signal may be cut off by a tunnel or the like, and it is relatively likely that the operation is useless. In addition, the detection is not possible at a very high speed. Rotation speed is low.

Next, the processing performed by the microcomputer 34 will be described based on a flowchart. For the sake of simplicity, each process will be described separately for each function, but these processes are selected and used in combination. These processes are started when the satellite broadcast receiver is activated, and are repeatedly performed.

(A) Basic swing processing (FIG. 8) In step S1, the C / N is read, and the routine proceeds to step S2.
In step S2, a branch process based on the C / N value is performed. C
If / N is equal to or less than the level α1 at which tracking is determined to be out of tracking, the process proceeds to step S3. If C / N is less than the inversion level α2, the process proceeds to step S4. Finish. Note that in the relationship of α1 <α2,
Α2 is set to a value that allows good reception when the C / N is equal to or more than α2. In step S3, a high-speed search, such as a 360-degree swing (or infinite rotation) of the antenna, is performed, the tracking is restored, and the process ends. In step S4, the antenna rotation direction is reversed, and the process ends.

(B) Swing Speed Control Process 1 (FIG. 9) In step S11, the swing time and the rotation speed of the automobile (moving body) are calculated by the above-described method. Step S1
In step 2, a branching process is performed according to the swing time. In the present embodiment, a condition is set that the swing time when the vehicle is stopped is 100 ms (millisecond), and the swing speed is not changed in the range of 60 to 140 ms. Further, the swing speed is detected for the swing in one direction (+ (right) direction). When the swing time is less than 60 ms, step S15 is performed. When the swing time is more than 140 ms, step S13 is performed. The swing time is 60 ms or more and 140 ms.
In the following cases, the process proceeds to step S14.

The process proceeds to step S13 when the swinging time is long, that is, when the rotating direction of the antenna is opposite to the rotating direction of the vehicle. Therefore, in step S14, a predetermined speed (5 ° / s) is added to the correction speed V, and the process proceeds to step S17. The process proceeds to step S15 when the swinging time is short, and therefore when the rotation direction of the antenna is the same as the rotation direction of the vehicle. Therefore, in step S16, the predetermined speed (5 ° / s) is subtracted from the correction speed V, and the process proceeds to step S17. Then, in step S16, the process proceeds to step S17 without correcting the correction speed V.

In step S16, the standard swing speed ± V0
The control signal is output to the motor drive circuit so that the control speed becomes the control speed VC obtained by adding the correction speed V to the control speed (for example, ± 20 ° / s: + indicates rightward swing and − indicates leftward swing). In other words, when the rightward swing time is long (when the leftward swing time is short), the rightward rotational speed is increased (the leftward rotational speed is decreased), and the rightward rotational speed is decreased. If the swing time to the satellite is short (when the swing time to the left is long), reduce the rotation speed to the right (increase the rotation speed to the left) to obtain the satellite (ground) Is controlled so that the rotation speed with respect to is constant.

With this control, even if a rotational motion occurs in the moving object, it is possible to control the rotation speed of the antenna with respect to the satellite (the ground) so that the rotational motion of the moving object during tracking control is generated. In this case, the satellite can be prevented from being lost, and stable tracking control of the antenna can be performed.

(C) Swing Speed Control Process 2 (FIG. 10) In step S21, the rotation speed of the automobile (moving body) is calculated by the above-described method. In step S22, a branching process is performed according to the rotation speed of the vehicle. In the present embodiment, the rotation speed of the automobile is less than 10 ° / s,
/ S and 30 ° / s, the processing is changed. When the rotation speed is lower than 10 ° / s, step S25 is performed. When the rotation speed is higher than 30 ° / s, step S23 is performed. The rotation speed is 10 ° / s or more and 30 ° / s.
In the following cases, the process moves to step S24.

Since the operation proceeds to step S23 when the rotation speed of the vehicle is high, it is necessary to increase the rotation speed of the antenna with respect to the satellite. Therefore, step S23
In this example, the reference speed is set to 30 ° / s, and the speed obtained by reversing the sign of the detected vehicle rotation speed VM is added to the control speed, so that the rotation speed of the antenna with respect to the satellite is set to 30 ° / s. . In addition, since the process proceeds to step S24 when the rotation speed of the vehicle is medium, it is necessary to slightly increase the rotation speed of the antenna with respect to the satellite. Therefore, in step S24, the reference speed is set to 20 ° /
s and the control speed is the speed obtained by inverting the sign of the detected vehicle rotation speed VM, thereby setting the rotation speed of the antenna relative to the satellite to 20 ° / s. Then, the process proceeds to step S25 when the rotation speed of the vehicle is low or zero, so that it is not necessary to increase the rotation speed of the antenna with respect to the satellite. Therefore, in step S25, the reference speed is set to 10 ° / s, and the speed obtained by inverting the sign of the detected vehicle rotation speed VM is added to the control speed, thereby setting the rotation speed of the antenna with respect to the satellite to 10 °. / S.

According to such control, the rotation speed of the antenna with respect to the satellite (ground) is variably controlled in accordance with the rotation speed of the moving body. Therefore, the swing speed of the antenna during tracking control is increased more than necessary. Without the proper speed. Therefore, the tracking performance can be sufficiently improved, and at the same time, abrasion of mechanical parts such as motors and bearings, generation of noise,
Waste of power and the like can be suppressed.

(C) Swing Speed Control Process 3 (FIG. 11) In step S30, the rotational speed of the automobile (moving body) is calculated by the above-described method. In step S31, the rotational speed calculated in step S30 is differentiated to calculate a rotational acceleration A. In step S32, a branching process is performed according to the rotational acceleration of the vehicle. In the present embodiment, the rotational acceleration of the vehicle is less than 10 ° / s · s,
The processing is divided into cases where the value exceeds s · s and 20 ° / s · s. When the rotational acceleration falls below 10 ° / s · s, step S35, the rotational speed becomes 20 ° / s · s
Is exceeded, step S33, the rotation speed is 10 ° /
In the case of not less than s · s and not more than 20 ° / s · s, step S3
Move to 4.

Since the process proceeds to step S33 when the rotational speed of the vehicle is rapidly increasing, it is necessary to increase the rotational speed of the antenna with respect to the satellite. Therefore, in step S33, the reference speed is set to 30 ° / s, and the speed obtained by inverting the sign of the detected vehicle rotation speed VM is added to the control speed, thereby setting the rotation speed of the antenna with respect to the satellite to 30 °. / S. Further, the process proceeds to step S34 when the rotation speed of the vehicle is about to increase abruptly, so that the rotation speed of the antenna with respect to the satellite needs to be slightly increased. Accordingly, in step S34, the reference speed is set to 20 ° / s, and the speed obtained by inverting the sign of the detected vehicle rotation speed VM is added to the control speed. / S. And step S
Moving to 35, when the rotational speed of the vehicle is not changing much, there is no need to increase the rotational speed of the antenna relative to the satellite. Therefore, step S35
In this example, the reference speed is set to 10 ° / s, and the speed obtained by reversing the sign of the detected vehicle rotation speed VM is added to the control speed, thereby setting the rotation speed of the antenna with respect to the satellite to 10 ° / s. . If the swing speed of the antenna is controlled in accordance with both the rotation speed and the rotation acceleration of the automobile, finer control becomes possible.

According to such control, the rotation speed of the antenna with respect to the satellite (ground) is variably controlled in accordance with the rotation acceleration of the moving body, so that the swing speed of the antenna during tracking control is increased more than necessary. Without the proper speed. And since the control based on the acceleration has a strong tendency of the predictive control, particularly on a curved road where the car frequently rotates,
For example, it is effective on mountain roads and complicated coastal roads. Therefore, tracking performance can be sufficiently improved, and wear of mechanical parts such as motors and bearings, generation of noise, and waste of power and the like can be suppressed.

(C) Swing stop control processing (FIG. 12) In step S40, the rotation speed of the automobile (moving body) is calculated by the above-described method (detection of rotation speed based on reception signal level). In step S41, it is determined whether or not the rotation speed calculated in step S40 is 0. If 0, the process proceeds to step S42, and if not, the process proceeds to step S45. In step S42, the state of the vehicle is determined. If the state of the vehicle requires the antenna swing control, the process proceeds to step S45 for performing the swing control. Step S44 to stop vibration
Move on to The necessity of the swing control of the antenna is determined as follows.

(1) When the speed of the vehicle read from the speedometer of the vehicle is 0, the vehicle is in a stopped state, and therefore, the swing control of the antenna is unnecessary. Therefore, when the speed of the vehicle read from the speedometer of the vehicle is 0, the process proceeds to step S44, and when the speed of the vehicle is not 0, the process proceeds to step S45.

(2) A signal indicating the state of the parking brake is read from the parking brake state display section of the display of the vehicle, and when the parking brake is applied, the vehicle is in a stopped state, so that the antenna swings. Becomes unnecessary. Therefore, when the parking brake of the car is applied, the process proceeds to step S44, and when the parking brake is not applied, the process proceeds to step S45.
Move on to

(3) A signal indicating the state of the transmission is read from the transmission control device of the automobile or the shift position display section of the display. When the vehicle is in the neutral state or the parking state, the vehicle is in the stopped state, and the antenna No swing control is required. Therefore, when the transmission of the vehicle is in the neutral or parking state, the process proceeds to step S44, and otherwise, the process proceeds to step S45.

(4) The rotation speed signals of the left and right wheels are read from the wheel rotation speed sensors provided on the left and right wheels of the vehicle. If the rotation speed difference between the left and right wheels is 0, the vehicle is stopped or goes straight. In this state, the swing control of the antenna is unnecessary. Therefore, when the difference between the rotational speeds of the left and right wheels of the automobile is 0, the process proceeds to step S44, and when it is not 0, the process proceeds to step S45. Since it is not affected by the driving force of the engine, it is desirable to compare the rotation speeds of the non-driving wheels. Also, the anti-lock system in which the vehicle controls the braking force in accordance with the rotation state of the wheels to prevent tire locking. When a brake system is provided, the processing in the microcomputer 34 is simplified by using the wheel rotation speed data calculated by the antilock brake system.

(D) Swing inversion control processing (FIG. 13) This processing is an improvement of the basic swing processing shown in FIG. In step S50, the C / N detection unit 31
/ N is read, and the routine goes to Step S51. Step S51
Then, it is determined whether the C / N is equal to or more than the threshold value α. If the C / N is equal to or more than the predetermined value α, the process returns to step S50, and if not, the process proceeds to step S52. In step S52, the rotation direction of the turntable 22 is reversed, and the routine goes to step S53. In step S53, the threshold value of C / N is reduced to β, and the process proceeds to step S54.

In step S54, the C / N is read from the C / N detector 31, and the flow advances to step S55. Step S
At 55, the C / N area is determined, and branch processing is performed. C
If / N is less than the value γ that would be taken in the case of a blocked state such as a building shadow or the like, the flow proceeds to step S56, and the block processing (3
A high-speed search such as a 60 ° swing is performed, and the process ends. C
If / N exceeds the threshold β, the process moves to step S57, and the C / N threshold is returned to the original α. If C / N is equal to or smaller than the threshold value β and equal to or larger than γ, the process returns to step S54, and the area determination processing is repeated.

According to the above-described processing, the C / N threshold value for judging the inversion is temporarily reduced when the antenna swinging operation is inverted, so that the C / N is temporarily reduced due to noise or the like. Even if it is slightly reduced, erroneous detection of the inversion timing can be prevented, and erroneous inversion operation can be prevented. It should be noted that a timer process is provided instead of the C / N area inversion processing in steps S55 to S57, and the C / N threshold value is set to β for a predetermined time from the time of the inversion processing of the turntable 22,
After the elapse of a predetermined time, control for returning the threshold value of C / N to α is also possible.

(E) Abnormal process (FIG. 14) In step S60, the maximum value CM of C / N in the immediately preceding swing operation is detected, and the routine goes to step S61. This is C /
This is performed by reading and monitoring the C / N from the N detector 31. In step S61, a moving average calculation of the maximum value of C / N is performed, and the moving average value CS is stored.
Move on to In the calculation of the moving average value, the stored moving average value CS is multiplied by a coefficient x (0 <x <1), and the maximum value CM of C / N in the immediately preceding swing motion is calculated by a coefficient (1-x )
, And adding these two. In step S62, the previous maximum value CM of C / N is compared with the moving average value C / N of C / N. If the difference is equal to or larger than a predetermined value, it is determined that the reception is abnormal, and the process proceeds to step S63.
If it is not determined that the reception is abnormal, the process ends.

In step S63, the immediately preceding swing condition (swing speed) is stored, and the flow advances to step S64. Step S6
In 4, the process of changing the swing speed is stopped using the swing condition (swing speed) as an initial setting value, and the process proceeds to step S65.
In step S65, the maximum value CM of C / N in the immediately preceding swing motion is detected, and the routine goes to step S66. Step S
At 66, the immediately preceding maximum value CM of C / N is compared with the moving average value CS of C / N, and if the difference is equal to or greater than a predetermined value, it is determined that the reception abnormality is continuing, and the process proceeds to step S67. The process proceeds to step S69 if it is not determined that the reception is abnormal.
Move on to

In step S67, it is determined whether or not the abnormal reception state has continued for a predetermined time. If the abnormal reception state has continued for a predetermined time or more, the process proceeds to step S68, and if not, the process returns to step S65. In step S68, a high-speed search process (360 ° swing operation or the like) is performed, and the process ends. In step S69, this process ends with the swing condition (swing speed) stored as the swing condition immediately before the occurrence of the abnormality.

By the above-described processing, when the reception is abnormal such that the C / N is abnormally lowered (when passing through a building shadow, a tunnel, or the like), the swing operation is initialized, and useless high-speed operation is performed. Since the swing operation is not performed, wear of mechanical parts such as a motor and a bearing, generation of noise, and waste of power and the like can be suppressed. Further, when the reception abnormality continues for a long time, a high-speed search such as a 360 ° swing operation is performed, so that the reception state is quickly normalized and the high-speed search is performed at a low speed. Also, wear of mechanical parts such as motors and bearings, generation of noise, and waste of power and the like can be suppressed. In this case, since the possibility that the abnormal state is continuing is relatively high, there is almost no influence on the reduction of the response (reduction of the return speed to the normal reception state) even at the low speed rotation. Then, when returning to the normal reception state, since the swing operation is performed under the swing condition immediately before the occurrence of the abnormality, it is possible to quickly and appropriately perform the swing operation.

[0067]

As described above, according to the present invention, there is provided an antenna tracking device capable of performing high-speed and stable tracking and reducing wear and fatigue of each component during driving, energy consumption and operation noise. Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an antenna tracking device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating characteristics and operations of an antenna.

FIG. 3 is a graph showing a change in a reception level when a moving object is stopped.

FIGS. 4A to 4D are graphs showing fluctuations in the reception level at each swing speed when the moving body stops.

5 (a) and 5 (b) are graphs showing a change in a reception level at the time of right and left swing operation when the moving body is stopped.

FIGS. 6A and 6B are graphs showing fluctuations in a reception level during a left-right swing operation when the moving body is rotating.

FIG. 7 is a graph showing a change in reception level when radio waves are cut off.

FIG. 8 is a flowchart showing basic swing processing.

FIG. 9 is a flowchart illustrating a swing speed control process 1;

FIG. 10 is a flowchart showing a swing speed control process 2;

FIG. 11 is a flowchart showing a swing speed control process 3;

FIG. 12 is a flowchart illustrating a swing stop control process.

FIG. 13 is a flowchart showing a swing reversal control process.

FIG. 14 is a flowchart illustrating an abnormal state process.

FIG. 15 is a block diagram showing a configuration of a conventional antenna tracking control device.

FIGS. 16A and 16B are explanatory diagrams showing a conventional step track method.

[Explanation of symbols]

 2 Antenna 3 Tracking controller 21 Antenna body 22 Turntable 31 C / N detector 32 Moving body motion detector 33 Drive controller

Claims (20)

[Claims] 1. An antenna tracking control device for tracking an antenna provided on a mobile object to receive broadcast radio waves from a satellite so as to face the satellite, comprising: A oscillating means for performing an oscillating operation of shifting over a predetermined angle to the left and right so that the direction becomes the oscillating center, and changing the oscillating center according to a state of a received signal during the oscillating operation. Antenna control means for controlling the direction of the antenna; rotation speed storage means for storing the rotation speed of the swinging operation; rotation for driving and controlling the swinging means in accordance with the rotation speed stored in the rotation speed storage means Speed control means, rotation state detection means for detecting a rotation state of the moving body in accordance with a reception state of broadcast radio waves at the time of the swing operation, and the moving body detected by the rotation state detection means And a rotation speed calculating means for increasing or decreasing the rotation speed stored in the rotation speed storage means by a predetermined amount according to the rotation state of the antenna tracking device. 2. A tracking control apparatus for an antenna provided to a mobile unit for receiving a broadcast wave from a satellite so as to track the direction of the satellite so as to face the satellite. A oscillating means for performing an oscillating operation of shifting over a predetermined angle to the left and right so that the direction becomes the oscillating center, and changing the oscillating center according to a state of a received signal during the oscillating operation. Antenna control means for controlling the direction of the antenna; rotation speed storage means for storing the rotation speed of the swinging operation; rotation for driving and controlling the swinging means in accordance with the rotation speed stored in the rotation speed storage means Speed control means, moving body rotation speed detection means for detecting the rotation speed of the moving body in accordance with the reception state of the broadcast radio wave during the swinging operation, and the moving body rotation speed detection means Rotation speed setting means for setting a rotation speed obtained by adding an addition rotation speed according to the rotation speed of the moving body and the rotation speed of the moving body as a rotation speed to be newly stored in the rotation speed storage means. An antenna tracking device, comprising: 3. An antenna tracking control device for tracking an antenna provided on a mobile object to receive a broadcast wave from a satellite so as to face the satellite, comprising: A oscillating means for performing an oscillating operation of shifting over a predetermined angle to the left and right so that the direction becomes the oscillating center, and changing the oscillating center according to a state of a received signal during the oscillating operation. Antenna control means for controlling the direction of the antenna; rotation speed storage means for storing the rotation speed of the swinging operation; rotation for driving and controlling the swinging means in accordance with the rotation speed stored in the rotation speed storage means Speed control means, moving body rotational acceleration detecting means for detecting the rotational acceleration of the moving body in accordance with the reception state of the broadcast radio wave during the swinging operation, and detecting by the moving body rotational acceleration detecting means. Rotation speed setting means for setting a rotation speed obtained by adding the added rotation speed according to the issued rotation acceleration of the moving body and the rotation speed of the moving body as a rotation speed to be newly stored in the rotation speed storage means; An antenna tracking device comprising: 4. The apparatus according to claim 1, wherein the rotation state detection means detects the rotation state of the moving body based on a time between a point in time when the reception signal level reaches a predetermined level during the swing operation. An antenna tracking device according to any of the preceding claims. 5. The rotation state detecting means detects a rotation state of a moving body by an integrated value of a signal level during a time when a reception signal level becomes a predetermined level during a swing operation. The antenna tracking device according to claim 1, wherein 6. The rotation state detection means detects the rotation state of the moving object by a change amount (differential value) of the reception signal level at a predetermined level during a time when the reception signal level becomes a predetermined level during the swing operation. 2. The antenna tracking device according to claim 1, wherein the antenna tracking device detects. 7. An antenna tracking control device for tracking an antenna provided on a mobile object to receive a broadcast wave from a satellite so as to face the satellite, comprising: A oscillating means for performing an oscillating operation of shifting over a predetermined angle to the left and right so that the direction becomes the oscillating center, and changing the oscillating center according to a state of a received signal during the oscillating operation. Antenna control means for controlling the direction of the antenna; and an inversion signal for comparing a received signal level with a predetermined comparison level during a swing operation, and inverting a displacement direction of the antenna when the received signal level becomes the comparison level. And a comparison level lowering means for lowering the comparison level for a predetermined period after the antenna is inverted. Antenna tracking device to. 8. The swinging means compares a received signal level with a predetermined comparison level during a swing operation, and sends an inverted signal for inverting a direction of displacement of the antenna when the received signal level becomes the comparison level to the swing means. The output device according to any one of claims 1 to 3, further comprising: an inverting unit that outputs the signal; and a comparison level lowering unit that lowers the comparison level for a predetermined period after the antenna is inverted. Antenna tracking device. 9. The antenna tracking device according to claim 7, wherein the predetermined period is a fixed time. 10. The antenna tracking device according to claim 7, wherein the predetermined period is a period in which the received signal level exceeds a return level higher than the comparison level. 11. A maximum value storing means for storing a maximum value of a received signal level in a swing operation, and calculating a difference between the received signal level in a swing operation and a maximum value stored in the maximum value storage means. Abnormality detection means for determining that reception is abnormal when the level difference is equal to or greater than a predetermined value; and change prohibition means for prohibiting change of the swing center when reception abnormality is detected by the abnormality detection means. The antenna tracking device according to claim 1, wherein: 12. When the abnormal condition is detected by the abnormal condition detecting means, a maintaining means for maintaining the rotational speed stored in the rotational speed storing means is provided. The antenna tracking device according to claim 11, wherein the tracking control is performed. 13. An exploration range enlarging means for widening a swing angle in the swing operation when detection of a reception abnormal state by the abnormality detection means has continued for a predetermined time or more. 13. The antenna tracking device according to claim 12. 14. The apparatus according to claim 13, further comprising: a swing speed reducing unit configured to reduce a swing speed in the swing operation when the swing range is widened by the search range expanding unit. Antenna tracking device. 15. A non-rotational state detecting means for detecting that the rotational speed of the moving body is 0, and a rotational speed of the moving body is 0 by the non-rotating state detecting means.
The antenna tracking device according to any one of claims 1 to 3, further comprising: stopping means for stopping the antenna at the center of the swing when it is detected that the antenna tracking is performed. 16. The vehicle according to claim 16, wherein the moving body is an automobile, and the non-rotational state detecting means detects that the rotation speed of the automobile is 0 based on a signal from a speedometer of the automobile. Item 16. An antenna tracking device according to item 15. 17. The non-rotating state detecting means detects that the rotational speed of the vehicle is 0 since the difference between the rotational speeds of the left and right wheels of the vehicle is 0. The antenna tracking device according to claim 15, wherein the antenna tracking device is a device. 18. The vehicle according to claim 18, wherein the moving body is an automobile, and the non-rotation state detecting means detects that the rotation speed of the automobile is 0 based on a parking brake state of the automobile. Item 16. An antenna tracking device according to item 15. 19. The non-rotating state detecting means detects that the rotation speed of the vehicle is 0 when the shift position of the transmission in the vehicle is a neutral position or a parking position. The antenna tracking device according to claim 15, wherein the antenna tracking device is a device. 20. The non-rotational state detecting means detects that the rotational speed of the moving body is 0 when the state of the received signal level in each of the horizontal swing motions is the same. The antenna tracking device according to claim 15, wherein: