JPH0593771A - Controlling device for attitude of antenna on traveling body - Google Patents

Abstract

PURPOSE:To enable an electric wave source to be acquired in a short time by providing a means for measuring a time from a point when a reception level is below a reference value and then for setting a search-scanning range according to it. CONSTITUTION:Assuming that a gyro error is generated at a specified angle each time a specified amount electric shielding time passes, a wide range of search-scanning time is set according to conical scanning corresponding to a measurement time of a measuring means. The search-scanning means search- scans a set range in step shape when a reception signal level is below a reference based on it. A reference value is determined corresponding to a measurement time. search-scanning in a narrow range is performed when the measurement time is less than the reference value, and search-scanning in a wider range than the above one is performed when the measurement time is equal to or more than the reference value. Therefore, the search-scanning range can be variable corresponding to the electric wave shielding time, thus enabling an electric wave source to be acquired again in a short time as much as possible according to conditions at that time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna on a moving body which corrects the antenna posture in a direction in which the receiving level becomes higher in response to a decrease in received signal level due to a change in posture of a moving body such as a vehicle with respect to a radio wave source. Attitude control device.

[0002]

2. Description of the Related Art When an antenna on a moving body is always directed toward a radio wave source, if tracking (reception tracking) is performed only by a continuous roving method such as a conical scan, a sufficient tracking performance can be obtained for a fast posture change of the moving body. If it is not obtained, or if it cannot be received by an obstacle such as a tunnel or building, it becomes impossible to track.

Therefore, a technique (gyro tracking) is also used, in which a gyro is used to detect a posture change of a moving body, a posture shift of an antenna (with respect to a radio wave source) due to the posture change is predicted and calculated, and the antenna posture is corrected by that amount. There is. According to this, when there is a radio wave obstacle such as a tunnel or a building, the gyro tracking interpolates the tracking during that time. Since gyro tracking is feedforward control, reception error is likely to occur only with gyro tracking, but reception tracking such as conical scanning corrects gyro tracking errors by feedback control. 1 of this kind of attitude control device
Japanese Patent Application Laid-Open No. 64-13801.
In this gyro tracking, the attitude of the moving body is detected by the yaw angle detector and the pitch angle detector, and the attitude of the antenna (azimuth direction and elevation direction) is changed according to the change of the attitude of the moving body.

[0004]

By the way, the gyro has a measurement error, and the accumulated value of this error increases in time series. If the radio wave is blocked for a long time in a tunnel, building, etc., the gyro error will be large when the radio wave reception is restored, and the deviation of the antenna attitude due to gyro tracking will be large. Since the antenna scanning in the reception tracking such as the conical scanning for searching the optimum pointing direction with reference to the antenna reception level is a small range, the radio wave source may not be captured even by the conical scanning. Therefore, when the antenna is out of the radio wave source (reception level is lowered), it is necessary to perform a tracking search over a wider area than the conical scan. However, if scanning is performed over a wide area at all times, it takes time to re-acquire the radio wave source, and it takes a long time to recover the reception.

An object of the present invention is to shorten the reacquisition time of the radio wave source by the tracking search as much as possible.

[0006]

The attitude control device of the present invention comprises a support mechanism (110-110) for rotatably supporting an antenna (Ant) on a moving body in the azimuth direction and the elevation direction.
155); Driving means (141, 151) for rotationally driving the antenna (Ant) in the azimuth direction and the elevation direction
Receiver (BSR) connected to (ANT); Attitude detecting means (30) for detecting the attitude of the moving body; Detection value (Y) of the attitude detecting means (30)
control means for correcting the attitude of the antenna so as to correct the deviation of the pointing direction of the antenna corresponding to the change of (as)
(4); Refer to the received signal level (BSs) of the receiver (BSR), and if it is equal to or greater than the reference value (TH2) that is less than the predetermined value (TH1), perform a conical scan of the antenna in a small range and receive the signal level ( Conical scanning tracking control means (4) for changing the attitude of the antenna (Ant) in the direction of increasing BSs; the received signal level (BSs) is the reference value (T
Measuring means (4) for measuring the time (TKK) from the time when it becomes less than H2); the scanning range (RL mode, RH mode) of the search scanning which is wider than the conical scanning is measured by the measuring means (4). Corresponds to the measurement time (TKK) and it is wide (RH mode)
Search range setting means (4) to be set; and when the received signal level is less than the reference value (TH2), the scanning range (RL mode, RH mode) set by the search range setting means (4) is stepwise searched. Search scanning control means (4) for scanning is provided. Symbols in parentheses indicate corresponding elements or corresponding matters in the embodiments shown in the drawings and described later.

[0007]

The accumulated value of the gyro error is small if the radio source is lost for a short time due to an obstacle or the like, and the accumulated value of the gyro error is large if the radio source is lost for a long time. That is, it can be said that the time after the radio wave is no longer received (radio wave cutoff time) and the accumulated value of the gyro error are roughly in a proportional relation.

Therefore, according to the present invention, the radio wave interruption time is set to a predetermined angle (eg, 0.1 seconds) every time a predetermined time elapses (eg, 1 second).
Assuming that a gyro error will occur only
The scan range (RL mode, RH mode) of the search scan which is wider than the conical scan is set corresponding to the measurement time (TKK) of (4). Based on the set search scan range, the search scan control means (4) sets the received signal level (BSs) to the reference value (TH
When it is less than 2), the set range is searched for in steps. In the preferred embodiment of the present invention, the measurement time (TKK)
The standard value (TK1) is set for the measurement time (TKK)
If it is smaller than (K1), a narrow range (but wider than conical scan) search scan (scan in RL mode) is performed. If the measurement time is longer than the reference value, a search scan wider than the range (RH Mode scanning).

Therefore, since the range of the search scan is made variable in accordance with the radio wave cutoff time, the radio wave source is recaptured in a time as short as possible according to the situation at that time. Further, when performing a narrow range search scan, the amount of driving of the antenna is reduced as compared to when performing a wide range search scan, so the deterioration speed of the drive mechanism is reduced and the durability of the drive mechanism is improved. Also, it consumes less power. Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0010]

FIG. 1 shows an embodiment of the present invention. This embodiment is mounted on the vehicle shown in FIG. 5, and controls the attitude of the BS antenna Ant for receiving the stationary satellite broadcast. The vehicle is equipped with a yaw angular velocity detector 30, which is a vibration type gyro, and detects the yaw angular velocity (rotational angular velocity in the course change direction) of the vehicle and outputs an analog signal (yaw angular velocity signal) to the interface 3. give. The interface 3 subjects the yaw angular velocity signal to electrical processing such as noise removal and amplification and gives it to the microcomputer 4. The microcomputer 4 is a CPU, R
A computer system including electronic circuit elements such as an AM, a ROM, and a system controller, which reads a yaw angular velocity signal after converting it into a digital signal.

Interfaces 3 and 5 are connected to the microcomputer 4, and the operation board 22 and the BS receiver BS are connected to these interfaces 3 and 5, respectively.
R, azimuth motor driver AZD and elevation motor driver ELD are connected.

The radio wave reception signal of the BS antenna Ant is BS
It reaches a receiver, where it is demodulated into a satellite broadcast signal and given to a display BSD, which displays a still satellite television broadcast image. The satellite broadcast signal is also given to the interface 5, which converts the radio wave reception signal into an analog signal BSs representing a signal level and gives it to the microcomputer 4. The microcomputer 4 digitally converts the analog signal BSs and reads it.

In both the azimuth motor driver AZD and the elevation motor driver ELD, an electric circuit (motor driver) for selectively supplying a forward rotation energizing current and a reverse rotation energizing current to the motor and a computer circuit mainly composed of a CPU ( Controller), and responsively responds to the step rotation instruction signal (direction + rotation angle) from the microcomputer 4 to urge the motor of each mechanism to rotate by the indicated angle, or In response to the continuous rotation instruction signal (direction + speed) from the microcomputer 4, the motor of each mechanism is rotationally energized at the speed instructed in the instructed direction, and further, the rotary encoder 148 and the elevator of the azimuth mechanism are driven. The electrical signals generated by the rotary encoder 157 of the transmission mechanism The azimuth orientation (rotation position) data and elevation position (rotational position) data, and updates the posture change due to antenna drive, azimuth data indicating the antenna attitude at that time always position register AZPR
And the elevation position register ELPR.

FIG. 2 shows a mechanism for supporting the BS antenna Ant and determining its posture. This mechanism is based on BS antenna A
nt is a biaxial rotation drive mechanism that rotationally drives in the azimuth direction (centered on the first axis Y) and in the elevation direction (centered on the second axis X). The antenna Ant is a plate-shaped circular beam antenna having a relatively wide reception range, and is fixed to the antenna bracket 110.

FIG. 7 shows the directional characteristics of the BS antenna Ant. The vertical axis is the CN ratio and the horizontal axis is the light-receiving surface of the antenna (circle)
Is an angle formed by a perpendicular line passing through the center of the radio wave and a straight line connecting the center with the radio wave source (stationary satellite). When this angle is about 8 ° or less, the CN ratio shows 50% or more of the maximum CN ratio (15 dB).

Referring again to FIG. 2, the horizontal shaft 113b (the center of which is the second axis X) is fixed to the angle 113a of the antenna bracket 110. The horizontal shaft 113b extends in a direction perpendicular to the drawing, and one end of the horizontal shaft 113b is rotatably supported by a support arm 121a via a bearing (not shown). The support arm 121a is fixed to the turntable 120. The other end of the horizontal shaft 113b is
It is rotatably supported by another supporting arm (not shown) similar to the supporting arm 121a via a bearing. The other support arm (not shown) is also a turntable 120.
Of the support arm 1 with respect to the cylindrical shaft 116 described later.
It is fixed at a position symmetrical to 21a.

The rotary table 120 is generally a disk-shaped spur gear, has a guide hole 120h in the center thereof, a gear 120a on the side peripheral surface thereof, and a fixed base 130 via a bearing 122. The gear 120a is mounted rotatably around a rotation center axis (first axis) Y of the gear 120a. A gear 144 meshes with the gear 120 a of the rotary base 120.
4 is rotationally driven by an azimuth drive motor 141 via a gear shaft 145 and a speed reducer 140. The speed reducer 140 and the motor 141 are fixed to a support base 146 fixed to the fixed base 130. A rotary encoder 148 is coupled to the gear shaft 145 and generates one electric pulse for each rotation of the gear shaft 145 by a predetermined small angle. This electric pulse is given to the azimuth motor driver AZD.

A switch 147 for detecting an azimuth home position is installed so as to face the lower surface of the rotary table 120, and the operator falls to the position on the lower surface of the rotary table 120 where the operator of the switch 147 faces. A tapered hole (one point) is engraved. The switch 147 is opened (OFF) when the operator is pushed on the lower surface of the turntable 120.
When the taper hole faces the operator, the operator enters the hole, and the switch 147 is closed (ON: home position detection). During one rotation of the rotary base 120, the operator of the switch 147 enters the taper hole and is turned on (home position detection). The opening / closing signal of the switch 147 is given to the azimuth motor driver AZD, and
It is also given to the microcomputer 4 via the interface 5. Referring to FIG. 3 showing an enlarged cross section taken along line BB-BB of FIG. 2, a worm wheel 143 is fixed to the gear shaft 145 inside the speed reducer 140.
A worm 142 that meshes with the worm wheel 143 is coupled to the rotation shaft of the motor 141 (FIG. 2).

When the motor 141 rotates in the forward direction, the gear 144 rotates in one direction and the turntable 120 rotates in one direction around the first axis Y. That is, the antenna Ant is the first
It rotates in the positive direction around the axis Y. When the motor 141 rotates in the reverse direction, the antenna Ant rotates in the reverse direction.

The cylindrical shaft 116 penetrates through the guide hole 120h of the rotary table 120, and is movable in the direction in which the first axis Y extends with respect to the rotary table 120. Although not shown,
A groove parallel to the first axis Y is engraved on the side circumferential surface of the cylindrical shaft 116, and a guide hole 120h of the rotary table 120 is parallel to the first axis Y and has a rail-shaped protrusion fitted in the groove. The ridges allow the cylindrical shaft 116 to move in the direction in which the first axis Y extends with respect to the rotary table 120, but cannot rotate about the first axis Y. Therefore, when the turntable 120 rotates about the first axis Y, the cylindrical shaft 116 also rotates about the first axis Y.

A pin 117 is provided on the upper end of the cylindrical shaft 116.
Is fixed, and the lower end of the link arm 115 is rotatably connected to the pin 117. The upper end of the link arm 115 is rotatably coupled to the pin 112 fixed to the angle 111 of the bracket 110.

Since the bracket 110 is separated from the angle 113a in the horizontal direction orthogonal to the direction in which the horizontal shaft 113b extends (the direction perpendicular to the paper surface of FIG. 2), when the cylindrical shaft 116 moves upward in FIG. Ant rotates counterclockwise about the horizontal axis 113b (upward rotation), and when the cylindrical shaft 116 moves downward, the antenna Ant rotates clockwise (downward rotation).

On the outer peripheral surface of the lower half of the cylindrical shaft 116, a ring-shaped gear 116a is engraved instead of being threaded. Each of the ring-shaped gears 116a (peaks and valleys) is parallel to the direction orthogonal to the first axis Y. The gear 154 meshes with the ring-shaped gear 116a.

Referring to FIG. 4 showing an enlarged cross section taken along the line CC--CC of FIG. 2, the worm wheel 153 of the speed reducer 150 is fixed to the gear shaft 155 of the gear 154. The worm 152 meshing with the worm wheel 153 is coupled to the rotation shaft of the elevation drive motor 151 (FIG. 2). The speed reducer 150 and the motor 151 are fixed to a support base 146 fixed to the fixed base 130.

When the elevation drive motor 151 rotates forward, the gear 154 rotates clockwise in FIG. 2, the cylindrical shaft 116 moves downward, and the antenna Ant rotates clockwise (rotates upward). When the motor 151 rotates in the reverse direction, the antenna Ant rotates counterclockwise (rotates downward).

When the cylindrical shaft 116 moves up and down, a rotational force about the pin 117 is applied to the link arm 115, and the link arm 115 rotates about the pin 117. In order to prevent the rotation of the link arm 115 from being hindered during this rotation, a split groove 118 is formed on the upper end of the cylindrical shaft 116 as shown in FIG.

As mentioned above, the gear 154 meshes with the gear 116a of the cylindrical shaft 116.
Each of the peaks and valleys of the ring forms a ring that circulates the side circumferential surface of the cylindrical shaft 116, and since they are parallel to the first axis Y, both when the gear 154 is stationary and when it is rotating. But the cylindrical shaft 116
The rotation is not restricted by the gear 154 and the gear 154 can rotate about the first axis Y, and the rotation itself causes the cylindrical shaft 11 to rotate.
6 does not move up and down with respect to the gear 154. Referring to FIG. 4, the gear shaft 155 of the gear 154 has a cam plate 156.
Is stuck. This cam plate has a step at the outer peripheral edge. The upper limit switch 158 and the lower limit switch 159 are opposed to the outer peripheral surface of the cam plate 156, and when the elevation rotation angle of the antenna Ant is within a predetermined range, the operators of the switches 158 and 159 act as the cam plate 156. Both the switches 158 and 159 are open (OFF) because they face the outer surface of the small radius. When the antenna Ant rotates clockwise and reaches the clockwise rotation limit position (upward limit), the taper surface of the cam plate 156 that switches from the small radius outer peripheral surface to the large radius outer peripheral surface pushes the operator of the switch 158. Switch 158
Switches to closed (on). When the antenna Ant rotates counterclockwise and reaches the counterclockwise rotation limit position (downward limit), the tapered surface of the cam plate 156 that switches from the small radius outer peripheral surface to the large radius outer peripheral surface pushes the operator of the switch 159, As a result, the switch 159 is closed (ON). Opening / closing signals of the switches 158 and 159 are given to the elevation driver ELD and also given to the microcomputer 4 via the interface 5.

The rotary encoder 1 is attached to the worm 152.
57 is coupled to generate one electric pulse per rotation of the worm 152 by a predetermined small angle. This electric pulse is given to the elevation motor driver ELD.

As described above, the antenna Ant is connected to the first axis Y.
A speed reducer 140 and a motor 141 for rotating and driving the antenna Ant, and a reducer 150 and a reducer 150 for rotating and driving an antenna Ant about a horizontal axis 113b (second axis X) perpendicular to the first axis Y. Since the motors 151 are both fixed to the fixed base 130, the motors 14
Sliding connection means is not required to supply power to 1, 151.

Referring to FIG. 2, the converter Conv
Is attached to the antenna bracket 110, and the antenna A
1 GHz of 12 GHz band satellite broadcast radio waves received by nt
Convert to band BS-IF. The converted signal is sent to the rotary joint 160 via the cable 161,
Then it reaches the BS receiver BSR (FIG. 1).

However, the converter Conv fixed to the bracket 110, together with the antenna Ant, has the first axis Y.
Since it rotates about the horizontal axis 113b and the signal line and the receiving wire of the converter Conv and the BS in the fixed part.
It is necessary to connect the signal line and the power supply line of the receiver BSR via the sliding connection means.

In this embodiment, the elevation rotation range of the antenna Ant about the horizontal axis 113b is 46.
Since the electric cable 161 composed of the signal line and the receiving line of the converter Conv has relatively high flexibility, the electric cable 161 including the signal line and the receiving line of the converter Conv is allowed to have an extra length.
It is also possible to rotate more than a degree, and the rotary joint 160 is wired through the inner hole of the cylindrical shaft 116 and connected thereto. An electrical cable 162 from the BS receiver BSR is connected to the rotary joint 160, and the rotary joint 160 allows the cable 1
The leads of 61 and 162 to be electrically connected to each other are electrically connected to each other despite the relative rotation about the first axis Y. With respect to the rotation of the antenna Ant about the horizontal axis 113b, the cable 161 swings about the pin 117 as a center.

As described above, in this embodiment, only one set (the rotary joint 160) of the sliding connection means is used.

The elevation drive motor 151 of the elevation mechanism (150, 151) rotationally drives the drive gear 154, but since the cylindrical shaft 116 reciprocally driven by the drive gear 154 slides on the rotary base 120, The turntable 120 and the azimuth mechanism (144, 140, 141) that rotationally drives the turntable 120 are not driven by the elevation mechanism (150, 151) and do not become a load on the elevation mechanism (150, 151). The object supported by the elevation mechanism (150, 151) is
In effect, the BS antenna Ant, the BS converter Conv,
A link arm 115 and a cylindrical shaft 116,
Since the load is small, the inertial force is small, and the azimuth drive and elevation drive of the BS antenna Ant centering on the second axis (X) can be performed at a relatively high speed, and the positioning can be performed with relatively high accuracy. obtain.

Referring to FIG. 8, the operation board 22 includes
Azimuth data of antenna Ant (Azimuth data),
LCD (2) for displaying elevation (depression) data (hereinafter elevation data), reception level and various messages.
(Dimensional liquid crystal display board) 23, a start (START) key 24 for instructing the automatic attitude control of the antenna 30, a stop (STOP) key 25 for instructing to stop the automatic attitude control of the antenna Ant,
Up key (U key) for manual attitude control 2
6, down key (D key) 27, light key (R key) 2
8 and a left key (L key) 29 are provided.

FIG. 9 shows an outline of the control operation of the microcomputer 4. A power supply circuit (not shown) is connected to an on-vehicle battery to apply a predetermined voltage to each part of the electric circuit shown in FIG. 1 when the ignition key of the vehicle is in a position where the engine is operating (the ignition key switch is on). .. A battery voltage for energizing the motor is also applied to the motor drivers AZD and ELD.

The microcomputer 4 "system initializes" when a predetermined voltage is applied to itself.
(Subroutine 1: In the following, in parentheses, the word "step" or "subroutine" will be omitted and only the numbers attached to it will be executed.) To set the internal registers, timers, counters, etc. to the contents set to the standby state. , Set a signal that specifies non-operation (deactivation) to the output port. Then, in "system initialization" (1), "initialization of antenna attitude" is executed. In this case, the antenna Ant is set to the home position (switch 147 on) in the azimuth direction and the counterclockwise rotation (downward rotation) limit position in the elevation direction (downward limit position: switch 159 on), that is, the antenna Ant. Set to the posture origin and set the posture register (azimuth position:
Register AZPR / elevation position: register EL
Clear PR).

When the microcomputer 4 receives the Ready signal from both the motor drivers AZD and ELD, the microcomputer 4 executes a manual operation process of step 4 (hereinafter step is referred to as S) until the start key 24 is turned on. Make up.

The manual operation process will be described with reference to the flowchart shown in FIG. When the U key 26 is operated, the microcomputer 4 proceeds from S30 to S31, where it checks whether the elevation limit switch 158 is on (closed) or off (open). If the switch 158 is on (closed), the posture of the antenna Ant in the elevation direction is at the upper limit of the elevation angle, and further upward drive is impossible. If not, the elevation motor is moved in S32. The driver ELD is instructed to execute the upshift process by one step. When the D key 27 is operated, S3
From S3, the process proceeds to S34, where it is checked whether the elevation lower limit switch 159 is on (closed) / off (open). Antenna Ant if switch 159 is on (closed)
The attitude in the elevation direction is at the lower limit of the depression angle, and further downward drive is impossible, but otherwise S
1 step to the elevation motor driver ELD at 35
Instruct to execute the downshift process.

When the R key 28 is operated, the microcomputer 4 proceeds from S36 to S37 where it instructs the azimuth motor driver AZD to shift right by one step (clockwise rotation: forward rotation), and L When the key 29 is operated, the process proceeds from S38 to S39, where the azimuth motor driver AZD is instructed to shift 1 step left (counterclockwise rotation: reverse rotation).

Referring again to FIG. 11, the microcomputer 4 determines in S40 the motor drivers AZD, E.
Wait for 1step right shift, 1step left shift, 1step upshift or 1step downshift by LD,
In S41, the Az data and EL data transferred from the motor drivers AZD and ELD are read. Further, in S42, the reception level BSs is read and stored in the register L1, and in S43, the Az data, EL data and the reception level BSs of the register L1 are displayed on the LCD2.
Display in 3.

The microcomputer 4 uses S3 (FIG. 6).
When the START key 24 is turned on at
5, the "initial search" S5 shown in FIGS. 12, 13, 14, 15, and 16 is executed.

The contents of the "initial search" S5 will be described with reference to FIGS. 12, 13, 14, 15, and 16. First, the concept of the "initial search" S5 will be described with reference to FIG. .. In this case, the attitude of the antenna Ant in the elevation direction is monitored while monitoring the reception level BSs.
From the position indicated by the data in the register ELS, first 10 ° upward (10 steps), then from the position indicated by the data ELS register 20 ° downward (20 steps),
Next, the position + 11 ° indicated by the data in the register ELS is changed to the upper limit position, and finally the position −21 ° indicated by the data in the register ELS is changed to the lower limit position. One step is changed at 1 ° step by step, and one revolution is scanned in the azimuth direction for each step change. One rotation scanning in the azimuth direction is also changed step by step at 1 degree. The reception signal level BSs of the receiver BSR is read every 1-step driving in the azimuth direction and every 1-step driving in the elevation direction, and it is checked whether it is equal to or higher than the threshold value TH2 for determining the receivability. Then, when it becomes equal to or higher than TH2, the "initial search" S5 ends there.

More specifically, referring to FIGS. 12 and 13, first, it is checked whether the data in the register ELS indicates the elevation origin (0) (S50a). In this embodiment, since the register ELS is assigned to one area of the memory in the microcomputer 4, when the power of the computer 4 is turned off, the content of the register ELS becomes data indicating zero when the power is turned on next time. Is becoming In this case, the posture of the antenna Ant is the origin (azimuth position: 0, elevation position: 0) in "system initialization" S1. Therefore, in this case, the computer 4 instructs the elevation driver ELD to drive the elevation to the midpoint of elevation (the midpoint between the upper and lower limits).
In response to this instruction, the driver ELD responds to the antenna Ant.
Is driven to the midpoint of elevation, and position data (EL data) of the midpoint of elevation is transferred to the computer 4. The computer 4 writes this position data (midpoint) in the register ELS (S50b).

When there is data other than the origin in the register ELS when proceeding to the "initial search" (S5), this means that the "initial search" has already been performed once after the system shown in FIG. 1 is powered on. (S5) The following antenna driving is executed, and for example, the elevation position when the reception level is suitable is written in S13a described later.
In this case, the data in the register ELS is not updated.
Next, in S50, the Az data at that time is stored in the registers A1 and A2, and the EL data is stored in the register E2.
Then, ELS + 10 is stored in the register E1.

Thereafter, the reception level is read in S52.
Then, when the value is equal to or higher than the predetermined level TH1, the microcomputer 4 immediately returns from S53 to the main routine (ends the initial search), but if it is lower than the predetermined level TH1, the microcomputer 4 proceeds to S54 and below to set the antenna Ant. Change the posture. In this attitude change, first, the elevation upper limit switch 158 is not turned on, and the elevation position E2 is the upper limit E of the first search area.
If it has not reached 1, the process proceeds from S54 to S55a to S56, where the 1st is set to the elevation motor driver ELD.
An instruction to shift up ep is given, and the value of the register E2 is incremented by 1 in S57. When the signal indicating the end of shift is received from the motor driver ELD, the microcomputer 4
The "azimuth scanning" AZS shown in 3 is executed.

In the "azimuth scanning" AZS, first, the reception signal level BSs is read (S58), and TH is TH.
It is checked if it is 2 or more (S59), and if it is TH2 or more, the "initial search" is ended. If it is less than TH2, it is checked whether the azimuth home position switch 147 is on (home position). If it is not on, the azimuth position A2 is 1 ° left of the initial position (Az data when entering the "initial search" S5). It is checked whether it is in the position (one rotation) (S62), otherwise 1step
A right shift is instructed to the driver AZD, and the current azimuth position data A2 is incremented by 1 (S6
4). Returning to S58 again, while monitoring the reception level,
Repeat the above. When the home position switch 147 is turned on, the antenna is rotated once to the left in the azimuth direction (S61). This is to avoid continuous rightward rotation of two or more rotations.

When the azimuth scan (AZS) makes one rotation in the right direction (A1 to A1-1: exactly one rotation by the right rotation from A1 to A1), the process returns to S52 and shifts up one step in the elevation direction. ..

Next, referring to FIG. In this way
From the elevation position of the register ELS to a position 10 ° above (up to the upper limit when the upper limit is reached by that time), even if the search is performed in the first area of the entire circumference in the azimuth direction, the reception level BSs must be equal to or higher than TH2, Next, in order to search to a position 20 ° below the elevation position of the register ELS, first, a downward shift to the elevation position of the register ELS is instructed (S65), and then S
In 50b, the Az data at that time is stored in the register A1.
And A2 and store the EL data in register E2 and E
Store LS-20 in register E1. And this time,
A search (AZS) in the azimuth direction is performed each time the drive is moved down one step in the elevation direction. In this case, the reception level BSs is read every time one step is shifted to the right in the azimuth direction and one step is shifted downward in the elevation direction. If the reception level BSs is TH2 or more, the initial search ends there, but the register ELS From the elevation position −
If the reception level BSs does not become equal to or higher than TH2 even in the search of the second small area of 20 °, the processing shown in FIG.
AZS), the elevation position of the register ELS + 1
The third small area from 1 ° to the upper limit is searched. And, even if this does not become TH2 or more, FIG.
In the processing shown in (S67 to AZS), the fourth small area from the elevation position -21 ° of the register ELS to the lower limit is searched.

When the reception level BSs does not reach TH2 or higher even after the search for the fourth small area is completed, it means that the proper reception level was not obtained even though the entire range of the antenna attitude was searched. Become. Therefore, in this case, the process proceeds from S54d to S55d, "Unreceivable" is displayed on the LCD 23, and S3 of the main routine (FIG. 9) is performed.
Return to.

In the "initial search" S5, the reception level BSs
When the attitude of the antenna Ant where is greater than or equal to the predetermined value TH1 is searched, the yaw angular velocity Yas detected by the yaw angular velocity detector 30 is read in S6a of FIG. And yaw angular velocity Yas
Is added to the contents AJT of the drift correction value register AJT, and the sum is written in the speed register YAR (S6).
b). Then, the data YAR of the speed register YAR (the code specifies the motor rotation direction and the absolute value of the numerical value specifies the speed) is transferred to the azimuth motor driver AZD (6c).

The azimuth motor driver AZD rotates the azimuth motor 141 so as to bias the antenna Ant to the right when the sign of the data YAR is minus (the car rotates left) and to the left when the sign of the data YAR is plus. The rotational speed of the antenna Ant is calculated by monitoring the pulse generated by the rotary encoder 148, and the speed of the azimuth motor 141 is controlled so that the rotational speed of the antenna Ant matches the speed specified by YAR.

When the data YAR is transferred to the azimuth motor driver AZD in S6c, the microcomputer 4
Starts a T1 timer (internal timer), which is not shown in the drawing. And S6c, S14, S17
In order to repeat the above and the like substantially at the cycle T1, S13
When returning from d, S16c or S17 to S6a, T1
Wait for the timer to time out, and if the time expires, S6
Go to a.

At the next step S10, the microcomputer 4 reads the reception level BSs, writes it in the register L1, reads the Az data and EL data indicating the attitude of the antenna Ant from the motor drivers AZD and ELD, and then these data are displayed on the LCD 23. indicate.

(A) In S13a and S13, the reception level BSs at this time, that is, the value of the register L1 and the predetermined levels THoff and TH1 (THoff>TH1> T).
H2) is compared, and the value of the register L1 is the predetermined level THof.
As long as f or TH1 or more, S6a → S6b → S6c
→ S8 → S10 → S13a → S13 → S13c → S13
The loop of d → S6a → ... is repeated to execute the attitude control process (a) of the antenna Ant based on the yaw angular velocity Yas detected by the yaw angular velocity detector 30. At this time, interrupt is prohibited (13c) and interrupt processing (Fig. 10)
Clear the value of TKK counted in (13
d).

That is, the reception level BSs is the first set value T
If the yaw angular velocity Yas changes while H1 or more, the attitude of the antenna Ant is corrected by a corresponding amount. If the STOP key 25 is turned on while continuing this, it is read in S8 and the process returns to S3 (standby state) of the flow shown in FIG.

The above-mentioned reception level BSs is high, and the antenna A is interlocked with changes in the yaw angular velocity Yas.
Loop for executing control to change the posture of nt (S6a →
S6b → S6c → S8 → S10 → S13a → S13 → S
13c → S13d → S6a → ...), when the reception level BSs, that is, the value of the register L1 becomes less than the predetermined level TH1, the microcomputer 4 causes S13
In S13b, the value of the register L1 is changed to the first level TH.
When the reception lower limit level TH2 is lower than 1, the "reception tracking" S14 is executed. When this is finished, the reception level BSs is further read (15) and compared with the reception lower limit level TH2 lower than the first level TH1 (16). In S16 and S13b, when the reception level BSs is lower than the reception lower limit level TH2, the microcomputer 4 sets s
After permitting the interrupt in 16a and executing the interrupt process (FIG. 10), the process proceeds to S17, and "tracking search" S17 is executed. On the other hand, if the reception level BSs is equal to or higher than the reception lower limit level TH2 in S16, the interrupt is prohibited (16
b), the value of TKK is cleared (16c).

Here, the interrupt processing will be described with reference to FIG. Interrupt processing is executed each time interrupt permission is given. In the interrupt process, the value of the register TKK is incremented by 1 and the process returns to the main routine (16d). In the main routine (FIG. 9), the interrupt is permitted when the reception level BSs is lower than the reception lower limit level TH2 (16a), and the interrupt is prohibited when the reception level BSs is equal to or higher than the reception lower limit level TH2 (13c, 16b). ), And since the time to return to step 6a is counted by the timer (not shown), the value of the register TKK indicates the passage of time from the time when the reception level BSs becomes less than the reception lower limit level TH2. The value of this TKK is the reception tracking (see FIG.
7, FIG. 18, FIG. 19, and FIG. 20), it is used when the search mode is selected and set.

(B) Next, the contents of the "reception tracking" S14 will be described with reference to FIGS. 17, 18, 19, and 20.

First, the concept will be described with reference to FIG. FIG. 25 is a conceptual diagram in which a scanning position when the antenna is conically scanned in a minute range is developed on a plane. In this conical scanning in a minute range, the main beam of the antenna Ant is rotated (1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → 1 → ...
・), The reception level is substantially constant during this rotation (scanning) when the target radio wave source is at the center of rotation of the antenna beam, but when the target radio wave source is off the rotation center of the beam, the reception level is It utilizes the phenomenon that it fluctuates and the maximum value appears. In FIG. 25, squares indicate one step (1 °) in the elevation direction (U / D) and the azimuth direction (R / L), and each point 1, 2, 3, 4, 5, 6, 7
And 8 are projection points of the main beam (center) of the antenna Ant, point 0 is the center of rotation of the antenna beam (direction of orientation in the posture immediately before the start of scanning), and arrows indicate the shift direction of the posture of the antenna Ant. It is also assumed that the point a has an isotropic antenna (isotropic point radio wave source). Hereinafter, "reception tracking" from the state in which the antenna Ant is pointing to the point 0
S14 will be described with reference to FIGS. 17 to 20 and 25.

1). The antenna Ant is driven from the starting point 0 to the point 1 (S70 to S73), and the reception level is stored at the point 1 (S70).
84) After that, shift 2 steps to the right in the azimuth direction and shift 1 step downward in the elevation direction to point 2 (S74)
The reception level BSs at point 2 is stored (S84).

2). Next, it is shifted one step to the right in the azimuth direction and two steps downward in the elevation direction to point 3 (S75), and the reception level at point 3 is stored (S84).

3). Next, the azimuth direction is shifted left by one step and the elevation direction is shifted down by two steps to point toward point 4 (S76), and the reception level at point 4 is stored (S84).

4). Next, it is shifted to the left in the azimuth direction by two steps and is shifted down by one step in the elevation direction to point 5 (S77), and the reception level at point 5 is stored (S84).

5). Then, it is shifted to the left in the azimuth direction by two steps and is shifted in the elevation direction by one step to point toward point 6 (S78) and the reception level at point 6 is stored (S84).

6). Then, it is shifted one step to the left in the azimuth direction and two steps in the elevation direction to point 7 (S79), and the reception level at point 7 is stored (S84).

7). Next, it is shifted one step to the right in the azimuth direction and two steps to the elevation direction, and is directed to point 8 (S80) and the reception level at point 8 is stored (S84).

As described above, one conical scan is completed, and the reception levels BSs of all the points (8 points) are registered in the registers POR1 to POR1.
Written on 8.

8). The maximum value SPmax and the minimum value Spmin are extracted from the reception levels of all the points (S87a), the difference between them is calculated, and it is checked whether the difference is within a predetermined range (dTH) (S87b). Within the predetermined range, there is little fluctuation in the reception level during one conical scan, and the center of the antenna is substantially pointing to the radio wave source, so the maximum value SPmax is less than the threshold value TH2 for reception failure determination. It is checked if there is (reception failure) (S87c), and if it is not reception failure, the reference value TH1 for good reception determination is updated to SPmax × 0.9 (87d), and this reference value TH1 exceeds the upper limit value THoff. Check if there is (S87e). If it exceeds, the reference value TH1 becomes the upper limit value THoff.
Rewrite to (S87f). If it does not exceed the above SP
Keep max × 0.9. Large fluctuations in reception level (S
In the case of Pmax-Spmin ≧ dTH) or in the case of poor reception (SPmax ≦ TH2), such a reference value T
H1 is not updated.

9). Next, the value of the register TKK counted in the interrupt process (FIG. 10) is compared with the predetermined value TK1, and if the former is larger than the latter, the search mode (mode in tracking search described later) Is set to RH (wide range search mode), and if the former is less than the latter, the search mode is set to RL (narrow range search mode) (S87h).
~ S87J).

10). Next, the points where the reception level is SPmax (points 1 to 8 in FIG. 25) are obtained (S87 to 91).

11). Then, the posture of the antenna Ant is determined so that the rotation center point of the antenna beam is aligned with the obtained highest reception level (S92).

12). "Drift correction processing" S93 is executed. The contents will be described later with reference to FIG.

When point a shown in FIG. 25 is the position of the radio wave source, the magnitude of the reception level is point 1> point 2> point 8
> Point 3> Point 7> Point 4> Point 6> Point 5, so the highest reception level is point 1. Therefore, the posture of the antenna Ant is set so that the directional center of the antenna beam is aligned with the point 1.

As described above, in the "reception tracking" S14, the maximum point of the reception level is detected by performing a conical scan in a minute range for one cycle around the center axis (point 0) of the initial antenna beam. Then, the attitude of the antenna Ant is set so that the central axis of the antenna beam is placed there. Therefore, when the radio wave source moves relatively to the antenna Ant, the attitude control is performed in a manner that the locus of the central axis (point 0) of the antenna beam moves together with the radio wave source, and the radio wave source of the antenna Ant is controlled. Tracking is performed.

Next, the content of the "drift correction process" S93 will be described with reference to FIG. The reception level BSs
Is below the lower limit level TH2, the “tracking search” described later
When S17 is executed and the antenna is receivable (when there is no interruption of radio waves), the posture is corrected to TH2 or higher, so that “reception tracking” S14 (hence the “drift correction processing” S93 included therein) is It should be noted that the reception level BSs is substantially repeated in the T1 cycle while the reception level BSs is lower than the first level TH1 and lower than the lower limit level TH2.

In the "drift correction process" S93, the posture position updated by conical scanning immediately before that (i = M of S92).
The contents (PR contents) are referred to (S131), and the updated position (0 to 8 in FIG. 25) from the position before update (0 point in FIG. 25).
Data A indicating the direction and the length of the azimuth direction component (the right R rotation direction is + and the left rotation direction −) of the vector connecting the two is calculated (S132), and this data A is added to the integration register SU.
Subtracting from the contents of M (reversing the sign because correction needs to be performed in the opposite direction, adding), the obtained value is added to the integration register SU.
The data is updated and written in M (S133). Then, the content of the conical scan execution frequency register N is incremented by 1 (S134), and it is checked whether the content N has reached the set value CNT (S135). If the set value is CNT, it is checked whether the absolute value of the content SUM of the integration register SUM is equal to or greater than the reference value ADT (S136), and AD
If it is T or more, the code of the data SUM is checked (S137).

If the sign of the data SUM is positive (shift to the left rotation direction), the content of the correction value register AJT is set to 1
The value is updated to a unit larger value (S138). Since the contents of the correction value register AJT are added to the drive speed instruction value of the azimuth drive motor 141 in S6b shown in FIG. 6, the azimuth drive speed (-YAR) corresponding to the yaw angular speed Yas is the normal rotation value (plus: right). The rotation speed is 1 unit of speed increase, and the reverse rotation value (minus: left rotation drive) is 1 unit of speed decrease.

If the sign of the data SUM is negative (shift to the right rotation direction), the content of the correction value register AJT is updated to a value smaller by one unit (S139). Since the contents of the correction value register AJT are added to the drive speed instruction value of the azimuth drive motor 141 in S6b shown in FIG. 6, the azimuth drive speed (-YAR) corresponding to the yaw angular speed Yas is
When the value is the forward rotation value (plus: right rotation drive), the speed is reduced by 1 unit, and when the reverse rotation value (minus: left rotation drive), the speed is increased by 1 unit.

When the above-described processing of S136 to S139 is completed, the conical scan execution frequency register N is cleared (S1
40), and clears the integration register SUM.

The "drift correction process" S9 described above
The contents of item 3 are summarized as follows. That is, S7
Every time the conical scanning from 0 to S80 and the updating of the antenna attitude (S87 to S92) based on it are performed once, the azimuth component of the update vector (attitude change direction and change amount) is
It is accumulated in the register SUM. Then, each time CNT is executed, the tendency of posture deviation in the azimuth direction is determined based on the contents of the register SUM, and the azimuth drive motor speed instruction value (-YAR) is corrected so as to correct this tendency in response to this tendency. Drift correction value AJT is adjusted. Since S6a, S6b, and S6c are executed immediately before the above-mentioned one-time conical scanning and posture setting (b) (see FIG. 9),
While (B) is repeatedly performed, the attitude control (A) is also being executed.

One Conical Scan and Posture Setting (B)
When the above is finished, the reception level is not always equal to or higher than TH1. The reception level is T by conical scanning and attitude setting (b).
When it becomes H1 or more, only the above attitude control (a) is executed, but when the reception level does not become TH2 or more even by the conical scanning and the attitude setting (b), the microcomputer 4 performs the "tracking search". "S17 is executed.

(C) The contents of the "tracking search" S17 are shown in FIGS. 21, 22 and 23, and the schematic diagrams for explaining the processing concept of the "tracking search" S17 are shown in FIGS. Referring to these drawings, S100 is an initial setting, and the state in which the antenna Ant is directed to the point b shown in FIGS. 26 and 27 is assumed to be when TSC = 0. Next, the search mode set by the above-mentioned reception tracking is checked, the processing shown in FIGS. 21 and 23 is executed when the search mode is RL, and the processing shown in FIGS. 22 and 23 is executed when the search mode is RH. Run. Note that FIG. 26 is a schematic diagram for explaining the processing concept in the search mode RL.
7 is a schematic diagram for explaining the concept of processing in the search mode RH.

(1) When the search mode is RL.

1-1). In S101, check whether the TSC value is 4 or less. As long as the TSC value is 4 or less, proceed to S102 and S1
Check the state of the switch 158 with 02, and if it is not on, S1
At 03, the motor driver ELD is instructed to shift up one step. This is the scan from points 0 to 5 in FIG. S101
If the TSC value is 5 or more, the process proceeds to S104.

1-2). In S104, it is checked whether the TSC value is 54 or less. As long as the TSC value is 54 or less, the process proceeds to S105, and the motor driver AZD is instructed to shift right by one step.
This is the scan from points 5 to 55 in FIG. S104 for T
When the value of SC is 55 or more, the process proceeds to S106.

1-3). In S106, it is checked whether the TSC value is 64 or less. As long as the value of TSC is less than 65, the process proceeds to S107, the state of the switch 159 is checked in S107, and if not ON, the motor driver ELD is instructed to shift 1 step down in S108. This is the scan from points 55 to 65 in FIG.
When the TSC value is 65 or more in S106, the process proceeds to S109. 1-4). In S109, it is checked whether the TSC value is 164 or less.
As long as the value of TSC is 164 or less, the process proceeds to S110, and the motor driver AZD is instructed to shift left by one step. This is Figure 26
Scanning from points 65 to 165. When the TSC value is 165 or more in S109, the process proceeds to S111.

1-5). In S111, check whether the TSC value is 174 or less. As long as the value of TSC is 174 or less, the process proceeds to S112, the state of the switch 158 is checked in S112, and if not ON, the motor driver ELD is instructed to shift up one step in S113. This is the scan from points 165 to 175 in FIG. When the value of TSC is 175 or more in S111, the process proceeds to S114.

1-6). In S114, it is checked whether the TSC value is 224 or less. As long as the TSC value is 224 or less, the process proceeds to S115, and the motor driver AZD is instructed to shift right by one step.
This is the scanning of points 175 to 225 (previous point 5) in FIG. If the TSC value is 225 or more in S114, the process proceeds to S116.

1-7). As long as the value of TSC is 229 or less in S116, proceed to S117 to check the state of the switch 159 in S117,
If it is not ON, the motor driver ELD is instructed to shift 1 step down in S118. This is point 225 in Figure 26 (point 5 above).
Up to point 230 (previous point 0) is scanned.

1-8). When the value of TSC is 230 or more in S116, and when the shift is instructed as described above and the shift is completed, S120 is executed to read the reception level, and whether it is TH2 or more in S121. Check
When it is TH2 or more, the process returns to the main routine (FIG. 9).
When it is less than TH2, the reception level BSs is read again in S123, it is checked in S124 whether it is the second set value TH2 or more, and if it is TH2 or more, the process returns to the main routine. The value is updated to a value larger by 1, and the process proceeds to S101 via S100a.

The above S101 to S119 (FIG. 21), S120 to S125
By the process of (FIG. 23), until the reception level BSs becomes equal to or higher than the second set value TH2, as shown in FIG.
Starting from (0), points 1, 2, 3, ... 230
Search scanning is performed on a locus following (0) in this order,
At each point, it is checked whether the reception level becomes TH2 or higher. When the point 230 (b = 0) is reached while it is less than TH2, that is, when the original start point is returned, the TSC is reset to 0 in S119, and the same search scanning is performed from the point b.

(2) When the search mode is RH.

2-1). In S101a, it is checked whether the TSC value is 9 or less. As long as the value of TSC is 9 or less, the process proceeds to S102a, the state of the switch 158 is checked in S102a, and if not ON, the motor driver ELD is instructed to shift up one step in S103. This is the scan from points 0 to 10 in FIG. When the TSC value is 10 or more in S101a, the process proceeds to S104a.

2-2). In S104a, it is checked whether the TSC value is 109 or less. As long as the value of TSC is 109 or less, the process proceeds to S105a, and the motor driver AZD is instructed to shift right by one step.
This is the scan from points 10 to 110 in FIG. S104
If the TSC value is 110 or more in a, the process proceeds to S106a.

2-3). In S106a, it is checked whether the TSC value is 129 or less. As long as the TSC value is smaller than 130, the process proceeds to S107a, the state of the switch 159 is checked in S107a, and if not ON, the motor driver ELD is instructed to shift down by one step in S108a. This is the scanning of points 110 to 130 in FIG. When the TSC value is 130 or more in S106a, S109a
Go to.

2-4). In S109a, it is checked whether the TSC value is 329 or less. As long as the TSC value is 329 or less, the process proceeds to S110a, and the motor driver AZD is instructed to shift left by one step.
This is the scanning of points 130 to 330 in FIG. S1
If the value of TSC is 350 or more in 09a, proceed to S111a.

2-5). It is checked in S111a whether the TSC value is 349 or less. As long as the value of TSC is 349 or less, the process proceeds to S112a, the state of the switch 158 is checked in S112a, and if not ON, the motor driver ELD is instructed to shift up one step in S113a. This is the scanning of points 330 to 350 in FIG. When the TSC value is 350 or more in S111a, S114a
Go to.

2-6). In S114a, it is checked whether the TSC value is 449 or less. As long as the TSC value is 449 or less, the process proceeds to S115a, and the motor driver AZD is instructed to shift right by one step.
This is scanning of points 350 to 450 (previous point 5) in FIG. If the TSC value is 225 or more in S114a, the process proceeds to S116a.

2-7). As long as the value of TSC is 459 or less in S116a, the process proceeds to S117a, the state of the switch 159 is checked in S117a, and if it is not on, the motor driver ELD is set to 1s in S118a.
tep Down shift command. This is the scanning from the point 450 (previous point 5) to the point 460 (previous point 0) in FIG.

2-8). When the value of TSC is 460 or more in S116a, and when the shift is instructed as described above and the shift is completed, S120 is executed, the reception level is read, and in S121, it is TH2 or more. Check
When it is TH2 or more, the process returns to the main routine (FIG. 9).
When it is less than TH2, the reception level BSs is read again in S123, it is checked in S124 whether it is the second set value TH2 or more, and if it is TH2 or more, the process returns to the main routine. The value is updated to a value larger by 1, and the process proceeds to S101a via S100a.

The above S101a to S119a (FIG. 22), S120 to S12
By the processing of 5 (FIG. 23), until the reception level BSs becomes equal to or higher than the second set value TH2, as shown in FIG. 27, starting from point b (0), points 1, 2, 3, ...・ 46
Search scanning is performed on a locus that follows 0 (0) in this order, and it is checked at each point whether the reception level has become TH2 or higher. When it reaches the point 460 (b = 0) while it is less than TH2, that is, when it returns to the original start point, the TSC is reset to 0 in S119a, and the same search scanning is performed from the point b.

As described above, the scanning range of this search scan is determined by the value of the register TKK (see S87h to S87j), and when the value of TKK is less than or equal to the predetermined value TK1 (when the signal level of the received signal BSs is less than TH2, 26 is performed, the search scanning in the narrow range shown in FIG. 26 is performed, and when the value of TKK is larger than the predetermined value TK1 (the time after the signal level of the received signal BSs becomes less than TH2). Is long), as shown in FIG. 27, search scanning is performed in a range approximately twice the scanning range shown in FIG.

Even during such a search scan, the motor energizing parameter set (S6
a), S6b, and S6c) are executed and the attitude change corresponding to the yaw angular velocity Yas is executed, so that the position of the base point (b = 0) does not change while the attitude of the vehicle does not change. Also, if the posture of the vehicle changes, the base point automatically shifts accordingly.

While radio waves are blocked by obstacles,
The above-mentioned "tracking search" S17 is repeated, and if the posture of the vehicle changes during that time, the base point of the tracking search is shifted in conjunction with it. Therefore, when the radio wave is blocked, the position of the beam center axis of the antenna immediately before that is set as the base point (b = 0:
26), the search scanning of the locus as shown in FIG. 26 is repeated until the radio wave is received, and if there is a change in the posture of the vehicle during that time, the base point shifts in conjunction with it.

In summary, (a) while the reception level BSs is equal to or higher than the first level TH1, the attitude of the antenna Ant is changed in association with only the yaw angular velocity Yas of the automobile, that is, only in response to the change in attitude. It

(B) When the reception level BSs is less than TH1 and more than TH2, along with the above (a), the conical scan and the change of the antenna attitude in the optimum pointing direction obtained by it, and whether or not the reception level is good or not. When the reference value TH1 for determining the value is updated and the value of TKK counting the time after the reception level becomes less than TH2 is less than or equal to the predetermined value TK1, the "tracking search" search mode is set. If RL (narrow range search mode) is set and the value of TKK is larger than the predetermined value TK1, the search mode of "tracking search" is RH (wide range search mode).
And Furthermore, the azimuth component of the attitude change vector is accumulated every time a conical scan + attitude change is performed.
Each time CNT is executed, the correction data AJT of the drift correction register AJT is updated in accordance with the accumulated value (indicating the deviation tendency in the azimuth direction) to the direction in which the deviation tendency in the azimuth direction becomes zero. Thus, the relative value of the speed of the azimuth drive motor 141 with respect to the yaw angular speed Yas is adjusted.

(C) The reception level BSs is the second level TH
When it is less than 2, in addition to the above (a), a tracking search (FIGS. 26 and 27) in a wider range than the conical scan is performed. The search at this time is performed in any one of the modes (RL or RH) that are selectively set according to the value of TKK counting the time after the reception level becomes less than TH2.

From the above description of the embodiments, the present invention can be applied to moving bodies other than road vehicles such as automobiles and trains, that is, ships,
It can be easily understood that it can be applied to aircraft and the like. In the above embodiment, the antenna is rotated by the azimuth drive motor 141 corresponding to the yaw angular velocity of the automobile at substantially the same speed in the direction opposite to the rotation (steering) direction of the automobile.
The yaw angular velocity may be integrated in a predetermined short time period to obtain the yaw angle change amount, and the antenna Ant corresponding to the yaw angle change amount may be rotationally driven in the opposite direction in the cycle. In addition, the time T counted after the reception level becomes less than TH2 is counted.
Two types of search modes are selected and set according to the value of KK, but the number of these modes may be any number.

[0110]

As described above, according to the present invention, it is assumed that a gyro error occurs by a predetermined angle (for example, 0.1 °) every time a predetermined time (for example, every one second) of radio wave interruption time elapses,
The scan range (RL mode, RH mode) of the search scan, which is wider than the conical scan, is set corresponding to the measuring time (TKK) of the measuring means (4). Based on the set search scan range, the search scan control means (4) searches the set range stepwise when the received signal level (BSs) is less than the reference value (TH2). In the preferred embodiment of the present invention, the reference value (TK1) is defined with respect to the measurement time (TKK), and the measurement time (TKK)
Is smaller than the reference value (TK1), a narrow range (but wider than conical scanning) search scan (scan in RL mode) is performed. Search scan (scan in RH mode)
Do.

Therefore, since the range of the search scan is made variable according to the radio wave cutoff time, the radio wave source is recaptured in a time as short as possible according to the situation at that time. Further, when performing a narrow range search scan, the amount of driving of the antenna is reduced as compared to when performing a wide range search scan, so the deterioration speed of the drive mechanism is reduced and the durability of the drive mechanism is improved. Also, it consumes less power.

[Brief description of drawings]

FIG. 1 is a block diagram mainly showing a configuration of an electric circuit unit according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of an antenna support mechanism of the embodiment.

3 is an enlarged sectional view taken along line BB-BB in FIG.

FIG. 4 is an enlarged sectional view taken along line CC-CC in FIG.

5 is an enlarged perspective view showing an upper surface of the turntable 120 shown in FIG.

FIG. 6 is a perspective view showing a state where the antenna Ant shown in FIG. 2 is mounted on a vehicle.

7 is a graph showing a radio wave reception characteristic of the antenna Ant shown in FIG.

8 is an enlarged plan view of the operation board 22 shown in FIG.

9 is a flowchart showing an outline (main routine) of a control operation of the microcomputer 4 shown in FIG.

FIG. 10 is a flowchart showing the contents of interrupt processing.

11 is a flowchart showing the contents of "manual operation" 4 shown in FIG.

FIG. 12 is a flowchart showing the contents of an “initial search” 5 shown in FIG.

FIG. 13 is a flowchart showing the contents of an “initial search” 5 shown in FIG.

FIG. 14 is a flowchart showing the contents of an “initial search” 5 shown in FIG.

FIG. 15 is a flowchart showing the contents of “initial search” 5 shown in FIG. 9.

16 is a flowchart showing the contents of "initial search" 5 shown in FIG.

FIG. 17 is a flowchart showing the content of “reception tracking” 14 shown in FIG. 9.

FIG. 18 is a flowchart showing the content of “reception tracking” 14 shown in FIG. 9.

FIG. 19 is a flowchart showing the content of “reception tracking” 14 shown in FIG. 9.

20 is a flowchart showing the contents of "drift correction" 93 shown in FIG.

FIG. 21 is a flowchart showing the contents of “tracking search” 17 shown in FIG. 9.

FIG. 22 is a flowchart showing the contents of “tracking search” 17 shown in FIG. 9 (RL mode).

FIG. 23 is a flowchart showing the contents of “tracking search” 17 shown in FIG. 9 (RH mode).

FIG. 24 is a schematic diagram showing changes in the pointing direction of the antenna Ant by the “initial search” 5 shown in FIGS. 12, 13, 14, 15, and 16.

FIG. 25 is a graph showing the attitude change amount of the antenna Ant by the “reception tracking” 14 shown in FIGS. 17, 18, and 19, where the horizontal axis represents the azimuth direction and the vertical axis represents the elevation direction.

FIG. 26 is a graph showing the attitude change amount of the antenna Ant in the RL mode of “tracking search” 17 shown in FIGS. 21, 22, and 23, where the horizontal axis represents the azimuth direction and the vertical axis represents the elevation direction. Show.

27 is a graph showing the attitude change amount of the antenna Ant in the RH mode of the “tracking search” 17 shown in FIGS. 21, 22, and 23, where the horizontal axis represents the azimuth direction and the vertical axis represents the elevation direction. Show.

[Explanation of symbols]

3: Interface 4: Microcomputer (control means, conical scan tracking control means, search scan control means, measuring means, search range setting means) 5: Interface Ant: Antenna (antenna) Conv: BS converter BSR: BS receiver (reception Machine) BSD: CRT AZD: Azimuth motor driver ELD: Elevation motor driver 10: Azimuth rotation drive mechanism 20: Elevation rotation drive mechanism 22: Operation board 30: Yaw angular velocity detector (posture detection means) 110: Antenna bracket 111, 113a, 114a: Angle 112: Pin 113b: Second axis (X) Y: First axis 115: Link arm 116: Cylindrical shaft 116a: Ring gear 120h: Guide hole 117: Pin 118: Split groove 120: Rotating table 20a: Gear 121a: Support arm 122: Bearing 130: Fixed stand 140: Reduction gear 141: Azimuth drive motor (driving means) 142: Worm 143: Worm wheel 144: Gear 145: Gear shaft 146: Support stand 147: Azimuth home position Switch 148: Rotary encoder 150: Reduction gear 151: Elevation drive motor (driving means) 152: Worm 153: Worm wheel 154: Gear 155: Gear shaft (110 to 155: support mechanism) 157: Rotary encoder 158: On elevation Limit switch 159: Elevation lower limit switch 160: Rotary joint 161, 162:
cable

Claims (1)

[Claims] 1. A support mechanism for rotatably supporting an antenna in an azimuth direction and an elevation direction on a moving body; a drive means for rotatably driving the antenna in the azimuth direction and the elevation direction; a reception connected to the antenna. Machine; attitude detecting means for detecting the attitude of the moving body; control means for correcting the antenna attitude to an attitude that corresponds to a change in the detection value of the attitude detecting means and corrects the deviation of the pointing direction of the antenna caused thereby; Conical scanning tracking control means for referring to the received signal level of the above and changing the attitude of the antenna in the direction in which the received signal level becomes higher by conical scanning the antenna in a small range when the received signal level is not less than a predetermined value; Measuring means for measuring the time from the time when the level becomes less than the reference value; the scanning range of the search scanning having a scanning range wider than the conical scanning. A search range setting means for setting a wide range when the measurement time of the measuring means is long; and a stepwise search of the scanning range set by the search range setting means when the received signal level is less than a reference value. A posture control device for an antenna on a moving body, comprising: search scanning control means for scanning.