JPH04204171A - Attitude controllor for antenna on moving body - Google Patents

Abstract

PURPOSE:To make it possible to keep the received quality constant and to shorten the receiving time even if the receiving level of an antenna on a moving body is fluctuated by providing an initial search control means for driving the antenna in the elevation and azimuth directions. CONSTITUTION:A first control means (CPU) 4 checks the received signal level BSs of a BS receiver BSR and changes the attitude of a BS antenna Ant in the direction where the signal level becomes high. Before the correction of the attitude of the antenna Ant, an initial search control means (CPU) 4'' drives the antenna Ant through an azimuth mechanism 141 and an elevation mechanism 151 stepwise in elevation and azimuth until the received signal level BSs of the receiver BSR becomes a preset value or higher. The driving amount of one step is determined as large when the signal level is high and determined as small when the signal level is low in response to the received signal level BSs of the receiver BSR which is checked by the CPU 4. In the environment wherein only the low received signal level BSs is obtained, the driving amount of one step of the antenna is made small. Therefore, the high receiving quality is obtained.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention monitors the reception level of an antenna mounted on a moving body such as a vehicle, and adjusts the antenna posture in a direction that increases the reception level. The present invention relates to an attitude control device for an antenna on a mobile body.

(Prior art) For example, an antenna used for communication with a fixed station, an artificial satellite station, etc. is installed on a mobile object such as a vehicle, a ship, or an aircraft for mobile communication, television broadcast reception, self-location recognition, etc. It will be installed.

As a method of always pointing this directional antenna toward a predetermined radio wave source or radio wave reflector, a continuous roving method such as conical scanning is used to actually receive radio waves while scanning the antenna, and search for the radio wave source based on the reception level. S is known to track people.

However, if the antenna is not picking up the radio wave source.

It was necessary to perform an omnidirectional search (initial search) to capture the radio wave source.

As the name suggests, the omnidirectional search scans the antenna over the entire movable range (posture origin to posture end point) until the reception level exceeds a set value.

(Issues to be solved by the invention) In omnidirectional search (initial search), when trying to shorten the time until the reception level reaches a set value or higher,
It is desirable that the directional angle displacement of the antenna from one reception level detection point in the azimuth direction and elevation direction of the antenna to the next reception level detection point be large.
Considering the reception quality, it is desirable that the directional angle displacement of the antenna is smaller, since level fluctuations due to omnidirectional search are smaller.

When actually receiving radio waves on a mobile object, the reception level obtained varies greatly depending on the weather and reception area, even if antennas with the same gain are used and there is no pointing error. Therefore, conventional omnidirectional search (initial search) In this receiving device, the directional angle displacement of the antenna was small and constant so that reception could be performed even when the reception level was low.

However, in an environment where a high reception level can be obtained, if the directivity angle displacement of the antenna is small, there is a problem that the time until reception becomes long and the power consumption increases because there is a lot of unnecessary movement of the antenna.

An object of the present invention is to keep reception quality constant even if the reception level of an antenna on a mobile body varies depending on the environment, and to shorten reception time.

[Structure of the invention]

(Means for Solving the Problems) The attitude control device of the present invention provides an antenna (Ant) on a moving object.
) support mechanism (110 to 155) that rotatably supports the antenna (
driving means (141, 151) for rotationally driving the antenna (
Receiver (BSR) connected to the receiver (Ant); Receiver (B
A first control means (4) that refers to the received signal level (BSs) of the SR) and changes the attitude of the antenna (Ant) in a direction in which it becomes higher via the driving means (141, 151):
Prior to changing the attitude of the antenna (Ant) of the first control means (4), the received signal level (BSR) of the receiver (BSR) is
The driving means (1
initial search control means (4) for driving the antenna (Ant) stepwise in the elevation direction and azimuth direction via the first control means (41, 151); and the first control means (4);
) refers to the received signal level (BSR) of the receiver (BSR).
s) and it is high and large (search mode =
RH), and the lower it is, the smaller it is (search mode = RL), which determines the one-step drive amount of the initial search control means (4).
Control means (4);

Note that symbols in parentheses indicate corresponding elements or corresponding matters in the embodiments shown in the drawings and described later.

(Function) The first control means (4) refers to the received signal level (BSs) of the receiver (BSR) and changes the attitude of the antenna (AfiI) in a direction in which the received signal level (BSs) increases via the drive means (141, 151). change. As a result, the antenna (Ant) is adjusted to a posture that provides a good reception level with respect to the radio wave source.

Prior to the attitude correction of the antenna (AnI), the initial search control means (4) performs the following steps until the received signal level (BSs) of the receiver (BSR) becomes equal to or higher than the set value (T) [2].
The antenna (Ant) is connected via the driving means (141, 151)
) is driven stepwise in the elevation direction and azimuth direction. The second control means (
4) is the receiver (BSR) that the first control means (4) refers to.
), the higher the received signal level (BSs), the higher it is (search mode = RH), and the lower it is, the lower it is (search mode = RL).

Therefore, for example, in the initial search, in an environment where a high received signal level (BSs) can be obtained, the one-step drive amount (direction angle displacement) of the antenna (Ant) is increased.
The time (initial search time) until the received signal level (BSs) of the receiver (BSR) reaches or exceeds the set value (TH2) is substantially shortened, and unnecessary movement of the antenna is reduced.

In addition, in an environment where a low received signal level (BSs) L- cannot be obtained, the one-step drive amount (
111 angle displacement) is reduced, high reception quality can be obtained.

Therefore, even if the reception level of the antenna on the mobile body varies depending on the environment, the reception quality can be kept constant and the reception time can be shortened.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Example) FIG. 1 shows an example of the present invention. This example is the second e
It is mounted on the vehicle shown in the figure, and controls the attitude of the BS antenna Ant for receiving geostationary satellite broadcasting.

Microninputer 4 has a CPU, RAM, ROM,
This is a computer system that includes electronic circuit elements such as system controllers.

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

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

Both the azimuth motor driver AZD and the elevation motor driver ELD consist of an electric circuit (motor driver) for selectively flowing forward rotation energizing current and reverse rotation energizing current to the motor, and a computer circuit (controller) mainly composed of a CPU. Each step rotation instruction signal (direction and ten rotation angles) is sent from the microcomputer 4.
In response to this, the motor of each mechanism is energized to rotate by the specified angle in the specified direction, or the microcomputer 4
In response to a continuous rotation instruction signal (direction + speed) from the rotary encoder 1 of the azimuth mechanism, the motors of each mechanism are energized to rotate in the specified direction and at the specified speed.
48 and elevation mechanism rotary encoder 1
Count the electric pulses generated by antenna A.
nt's azimuth attitude (rotational position) data and elevation attitude (rotational position) data are updated by the attitude change due to antenna drive, and the data indicating the antenna attitude at that time is always stored in the azimuth position register AZPR and the elevation position register ELPR. Hold.

FIG. 2a shows a mechanism for supporting the BS antenna Ant and determining its attitude. This mechanism connects the BS antenna Ant to
rotationally driven in the azimuth direction (centered on the first axis Y),
It is a two-axis rotational drive mechanism that rotates in the elevation direction (centered on the second axis X).

The antenna Ant is a flat circular beam antenna with a relatively wide reception range, and is attached to the antenna bracket 110.
is fixed to.

FIG. 3 shows the directivity characteristics of the BS antenna Ant. The vertical axis is the CN ratio, and the horizontal axis is the angle between a perpendicular line passing through the center of the light-receiving surface (circular) of the antenna and a straight line connecting the center and the radio wave source (geostationary 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. 2a, the antenna bracket 110
A horizontal shaft 113b (the center of which is the second axis X) is fixed to the angle 113a.

The horizontal shaft 113b extends in a direction perpendicular to the drawing, and one end thereof is rotatably supported by a support arm 121a via a bearing (not shown). The support arm 121a is fixed to the rotating table 120. horizontal axis 11
The other end of 3b is connected to the support arm 12 via a bearing.
It is rotatably supported by another support arm (not shown) similar to 1a. The other support arm (not shown) is also fixed to the rotary table 120 at a position symmetrical to the support arm 121a with respect to the cylindrical shaft 116, which will be described later.

The rotary table 120 is roughly a disk-shaped spur gear, and has a guide hole 120h in its center and a gear 120 on its side circumferential surface.
a, and to the fixed base 130 via the bearing 122,
The gear 120a is rotatably mounted around the rotation center axis (first axis) Y of the gear 120a.

A gear 144 is engaged with the gear 120a of the rotary table 120, and this gear 144 is connected to the gear shaft 145 and the reducer 14.
0 and is rotationally driven by an azimuth drive motor 141. The speed reducer 140 and the motor 141 are fixed to a support base 146 that is 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 through a predetermined small angle. This electric pulse is applied to an azimuth motor driver AZD.

A switch 147 for detecting the azimuth home position is installed opposite the bottom surface of the rotary table 120, and a tapered hole (into which the operator falls into) is provided at a position on the bottom surface of the rotary table 120 where the operator of the switch 147 faces. - dot) is engraved. The switch 147 has an operator that is connected to the turntable 12.
When pressed by the lower surface of 0, it is open (off), and when the tapered hole faces the operator, the operator enters the hole,
The switch 147 is closed (on: home position detection). While the turntable 120 rotates once, the switch 14
The operator No. 7 enters the tapered hole and turns on (home position detection). The open/close signal of the switch 147 is given to the azimuth motor driver AZD and also to the microcomputer 4 via the interface 5.

Referring to FIG. 2b, which shows a large cross-section taken along line IIB-nB in FIG. 2a, inside the reducer 140, the gear shaft 145
A worm wheel 143 is fixed to the worm wheel 143, and a worm 142 that meshes with the worm wheel 143 is connected to the rotating shaft of a motor 141 (FIG. 2a).

When the motor 141 rotates forward, the gear 144 rotates in one direction, and the rotary table 120 rotates in one direction about the first axis Y. That is, the antenna Ant rotates about the first axis Y in the positive direction. When the motor 141 rotates in the opposite direction, the antenna Ant rotates in the opposite direction.

The guide hole 120h of the rotary table 120 is connected to the cylindrical shaft 116.
passes through 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 carved on the side peripheral surface of the cylindrical shaft 116, and a groove parallel to the first axis Y is formed in the guide hole 120h of the rotary table 120. There is a rail-like protrusion, and this protrusion allows the cylindrical shaft 116 to move in the direction in which the first axis Y extends with respect to the rotary table 120.
Rotation around is not possible. Therefore, turntable 1
20 rotates around the first axis Y, the cylindrical shaft 116 also rotates around the first axis Y.

A bin 117 is fixed to the upper end of the cylindrical shaft 116, and the link arm 11 is rotatably attached to the bin 117.
The lower ends of 5 are joined. The upper end of the link arm 115 is rotatably connected to a pin 112 fixed to the angle 111 of the bracket 110.

The bracket 110 is attached to the horizontal axis 11 from the angle 113a.
3b in the horizontal direction perpendicular to the extending direction (perpendicular to the plane of the paper in FIG. 2a), so when the cylindrical shaft 116 moves upward in FIG. 2a, the antenna Ant
rotates counterclockwise (rotates upward) about the horizontal axis 113b, and when the cylindrical shaft 116 moves downward, the antenna Ant rotates clockwise (rotates downward).

The outer surface of the lower half of the cylindrical shaft 116 is carved with a gear 116a, which is ring-shaped rather than threaded. Each of the crests and troughs of the ring-shaped gear 116a is parallel to the direction perpendicular to the first axis Y. A gear 154 meshes with this ring-shaped gear 116a.

Referring also to FIG. 2C showing an enlarged cross section taken along the line nc-nc in FIG.
A worm wheel 153 is fixedly attached thereto. A worm 152 meshing with a worm wheel 153 is connected to a rotating shaft of an elevation drive motor 151 (FIG. 2a). The reducer 150 and the motor 151 are mounted on the fixed base 1
It is fixed to a support stand 146 fixed to 30.

When the elevation drive motor 151 rotates forward, gear 1
54 rotates clockwise in FIG. 2a to form the cylindrical shaft 11.
6 moves upward, and the antenna Ant rotates clockwise (rotates upward). When the motor 151 rotates in the opposite direction, the antenna A
nt rotates counterclockwise (rotates downward).

The link arm 11 is moved upward and downward by the cylindrical shaft 116.
5 is applied with a rotational force about the pin 117, and the link arm 115 rotates about the pin 117. During this rotation, so that the rotation of the link arm 115 is not hindered,
A groove 118 is cut into the upper end of the cylindrical shaft 116, as shown in FIG. 2d.

As described above, the gear 154 meshes with the gear 116a of the cylindrical shaft 116, and each of the peaks and valleys of the five gears 116a forms a ring that goes around the side circumferential surface of the cylindrical shaft 116. Since it is parallel to the first axis Y, the cylindrical shaft 116 is not restricted in rotation by the gear 154 and rotates about the first axis Y both when the gear 154 is stationary and when it is rotating. It can rotate, and the cylindrical shaft 116 is connected to the gear 15 by this rotation.
It does not go up or down with respect to 4.

Referring to FIG. 2c, a cam plate 156 is fixed to the gear shaft 155 of the gear 154. As shown in FIG. This cam plate has a step on its outer peripheral edge.

An upper limit switch 158 is provided on the outer peripheral surface of this cam plate 156.
and the lower limit switch 159 are facing each other, and when the elevation rotation angle of the antenna Ant is within a predetermined range, the operators of the switches 158 and 159 are opposite to the cam plate 1.
Since it faces the small radius outer peripheral surface of switch 15
Both 8 and 159 are open (off). When the antenna Ant rotates clockwise and reaches the clockwise rotation limit position (upward limit), the taber surface of the cam plate 156 that switches from the small radius outer circumferential surface to the large radius outer circumferential surface presses the operator of the switch 158, and thereby Switch 158 is turned closed (on). When the antenna Ant rotates in the direction of the half-hour hand and reaches the mint position (downward limit), the taber surface of the cam plate 156 that switches from the small radius outer circumferential surface to the large radius outer circumferential surface presses the operator of the switch 159. This turns switch 159 closed (on). switch 15
The opening/closing signals of 8 and 159 are from the elevation driver E.
The signal is applied to the LD and also to the microcomputer 4 via the interface 5.

A rotary encoder 157 is connected to the worm 152, and the rotary encoder 157 is connected to a rotary encoder 157.
Generates pulsed electrical pulses.

This electric pulse is generated by the elevation motor driver ELD.
given to.

As described above, the reducer 140 and the motor 141 are used to rotate the antenna Ant around the first axis Y, and the horizontal axis 113b (second axis X) is perpendicular to the first axis Y. Since the speed reducer 150 and the motor 151 for rotationally driving the motor 150 are both fixed to the fixed base 130, no sliding connection means is required to supply power to the motors 141 and 151.

Referring to FIG. 2a, the converter Conv is attached to the antenna bracket 110 and converts the 12 GHz band satellite broadcast radio waves received by the antenna Ant to the IGHz band BS-
Convert to IF. The converted signal is sent to the rotary joint 160 via cable 161 and then sent to the BS
This leads to the receiver BSR (Figure 1).

However, the converter Co fixed to the bracket 110
Since nv rotates around the first axis Y and the horizontal axis 113b together with the antenna Ant, = the signal line and power receiving line of the converter Conv and the BS receiver BSR in the fixed part
It is necessary to connect the signal line and the power supply line through a sliding connection means.

In this embodiment, since the elevation rotation range of the antenna Ant about the horizontal axis 113b only needs to be 360 degrees or less, the electric cable 161 consisting of the signal line and the power receiving line of the converter Conv is relatively flexible. In addition, the shaft has a length that allows for rotation of 360 degrees or more, and is connected to the rotary joint 160 by passing through the inner diameter of the cylindrical shaft 116. The rotary joint 160 has a BS receiver BS
An electrical cable 162 from R is connected, and this rotary joint 160 connects cables 161 and 16.
The two leads to be electrically connected to each other are electrically connected to each other despite 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 approximately about the bin 117.

Thus, in this embodiment, only one set of sliding connection means (rotary joint 160) 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 with respect to the rotary table 120, one rotary table 1
20 and an azimuth mechanism (144,
140°141) is the elevation mechanism (150°1
51) and is not driven by the elevation mechanism ('
150.151). The object supported by the elevation mechanism (150, 151) is substantially BS
The antenna Ant, the BS converter Conv, the link arm 115, and the cylindrical shaft 116 have a small load, so the inertia force is small, and the azimuth drive and elevation drive of the BS antenna Ant centered on the second axis (X) can be relatively performed. It is possible to perform the positioning at high speed and with relatively high precision.

Referring to FIG. 4, the operation board 22 has an antenna A.
++j azimuth data (hereinafter referred to as azimuth data), elevation (depression) angle data (hereinafter referred to as elevation data).

LC for displaying reception level and various messages
D (Two-dimensional liquid crystal display board)23. START key 24 for instructing automatic attitude control of antenna Ant
．． Stop (STOP) key 25. Instructs to stop automatic attitude control of antenna Aru. Up key (U key) for manual attitude control 26. Down key (D key) 2
7. right key (R key) 28, and left key (L key)
key) 29 is provided.

FIG. 5 shows an outline of the control operation of the microcomputer 4. A power supply circuit (not shown) is connected to the vehicle battery when the vehicle ignition key is in the engine operating position (ignition key switch on).
A predetermined voltage is applied to each part of the electric circuit shown in FIG.

Note that a battery voltage is also applied to the motor drivers AZD and ELD for energizing the motor.

When a predetermined voltage is applied to itself, the microcomputer 4 executes "system initialization" (subroutine 1: hereinafter, the words "step" and "subroutine" are omitted in parentheses, and only the numbers assigned to them are written). , internal register.

The timer, counter, etc. are set to the contents specified for the standby state, and a signal specifying non-operation (de-energization) is set to the output boat. Then, "System Initialize" (
In step 1), "initialization of antenna posture" is executed. In this case, the antenna Ant is set at the home position (switch 147 on) in the azimuth direction, and at the mint position (downward limit position (switch 159 on) with half-hour hand direction rotation (downward rotation) in the elevation direction, that is, the antenna Set the attitude as the origin and clear the attitude register (azimuth position register AZPR/elevation position register ELPR).

Upon receiving the Reidy signal from both motor drivers AZD and ELD, microcomputer 4 outputs 5T.
A loop is formed to execute the manual operation process of step 4 (hereinafter referred to as S) until the ART key 24 is turned on.

The manual operation process will be explained 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 turns on (close)/closes the elevation rim inch 158.
Check for off (open).

If switch 158 is on (closed), antenna A
nt's attitude in the elevation direction is at the upper limit of the elevation angle, and upward driving beyond that is impossible, but if not, in S32, the elevation motor driver ELD is set to 1.
Instructs execution of sleep up shift processing. Further, when the D key 27 is operated, the process proceeds from S33 to 334, where the lower elevation limit switch 159 is turned on (closed).
/ Check OFF (open). If the switch 159 is on (closed), the attitude of the antenna ^nl in the elevation direction is at the lower limit of the depression angle, and further downward movement is impossible. Instructs the motor driver ELD to execute a 15 step downward shift process.

When the R key 28 is operated, the microcomputer 4 proceeds from 336 to 337, where it instructs the azimuth motor driver AZD to shift I Nep to the right (clockwise rotation: forward rotation), and then presses the L key 29. If there is an operation, the process proceeds from 338 to S39, where the azimuth motor driver AZD is instructed to shift left by 15 steps (rotation in the direction of the half-hour hand: reverse rotation).

Referring again to FIG. 6, the microcomputer 4
Motor driver AZD in S40.

15 tep right shift, 154 ep left shift by ELD.

Wait for I Nep up shift or 15 step down shift to be executed, and at 541 motor driver AZD
, reads the AZ data and EL data transferred from the ELD. Further, in S42, the reception level BSs is read and stored in the register L1, and in 34.3, the reception level BSs is read and stored in the register L1.
The z data, the EL data, and the reception level BSs of the register L1 are displayed on the LCD 23.

The microcomputer 4, at 33 (FIG. 5),
When the 5TART key 24 is turned on, step 7a is activated in S5.
The "initial search" shown in FIGS. 7b and 7c is executed.

The contents of the initial search JS5 will be explained with reference to FIGS. 7a, 7b, and 7c. First, the concept of the initial search JS5 will be explained with reference to FIGS. 10a and 10b. Figure 10a shows the attitude of the antenna Ant in the azimuth direction and the elevation direction by 1 step per 16 steps.
The case where the received signal level BSs is detected every step (search mode = RL) is shown in Fig. 2.
A case is shown in which the received signal level BSs is detected for each step (search mode=RH). The search mode is determined in "reception tracking" S14, which will be described later.

In Fig. 10a (search mode = RL), while monitoring the reception level BSs, the attitude of the antenna Ant in the elevation direction is first moved upward by 10'' (10 steps), then upward from the position indicated by the data in the register ELS. 20' downward from the position indicated by the data in register ELS.
(20 steps), then change from the position +116 indicated by the data in the register ELS to the upper limit position, and finally from the position -216 indicated by the data in the register ELS to the downward mint position. Change one step at a time with one step 1", and scan one rotation in the azimuth direction for each step change. One rotation scan in the azimuth direction also takes one step 1".
Change it one step at a time. Every step of driving in the azimuth direction and every step of driving in the elevation direction, the received signal level BSs of the receiver BSR is read and checked whether it is equal to or higher than the threshold value 782 for determining whether reception is possible. However, when it reaches 782 or more, the message ``End initial search JS5.''

Next, in FIG. 10b (search mode=RH),
As in the case of Fig. 10a, while monitoring the reception level BSs, change the attitude of the antenna Ant in the elevation direction from the position indicated by the data in the register ELS, first upward at 10@, then at the position indicated by the data in the register ELS. from,
20 degrees downward, then from the position +11' indicated by the data in register ELS to the upper limit position, and finally to the register E
It changes from the position -21'' indicated by the LS data to the lower limit position, but unlike the case in Fig. 10a, it changes every 2 steps in the azimuth direction with 1 step 16, and every 2 steps in the elevation direction. , reads the received signal level BSs of the receiver BSR and checks whether it is equal to or higher than the threshold value TH2 for determining receivability, and if it becomes equal to or higher than 782, then [Initial search JS5 ends].

In the embodiment, the received signal level BSs of the receiver BSR is read every two step driving in the search mode ÷RH, and every one step driving in the search mode=RL, but there is no particular need to limit it to this.

To explain more specifically with reference to FIG. 7a, first, it is checked whether the data in the register ELS indicates the elevation origin (0) (350a). In this embodiment, the register ELS is allocated to an area of the memory in the microcomputer 4, so when the computer 4 is powered off, the next time the computer 4 is powered on, the contents of the register ELS will be zero data. It has become.

In this case, "In the system initialization JSI, the attitude of the antenna Ant is the origin (azimuth position: 0, elevation position 20). Therefore, in this case,
Computer 4 connects the elevation driver ELD to
Instructs elevation drive to the elevation midpoint (midpoint between the upper and lower limits). In response to this instruction, the driver ELD drives the antenna Ant to the midpoint of the elevation, and transfers the position data (EL data) of the midpoint of the elevation to the computer 4. Computer 4 writes this position data (midpoint) to register ELS (S
50b).

"Register E when proceeding to initial search J (S5)
When the LS has data other than the origin, this means that the antenna drive below "Initial Search J (S5)" has already been executed once since the power was turned on to the system shown in Figure 1, and for example, The elevation position when the reception level is suitable is written in 313a, which will be described later.In this case, the data in the register ELS is not updated.

After that, check the contents of register C3M.
), and its content is RH, the value of the coefficient
(Search mode ~ = RH) and set 550d), and if RL, set the value of X to 1 (Search mode = RL) (S
50 e). Note that the contents of the register C3M are written in a nonvolatile memory (not shown) included in the computer 4.

In addition, the contents of register C3M are "reception tracking" S, which will be described later.
14, it is set corresponding to the received signal level BSs.

Next, in S50, the Az data at that time is stored in registers A1 and A2, and the EL data is stored in register E2.
Then, ELS+10 is stored in register E1.

After this, the reception level is read at 352. When the value is equal to or higher than the predetermined level TH2, the microcomputer 4 immediately returns to the main routine from 353 (ends the initial search), but at the predetermined level TH2.
If it is less than 354, the process proceeds to step 354 and the attitude of the antenna Ant is changed. In this attitude change, first, if the elevation upper limit switch 158 is not on and the elevation position E2 has not reached the upper limit E1 of the first search area, the process proceeds from 354→555a-=S56, where the elevation motor driver The ELD is instructed to shift up by X (X=2° if search mode=RH, X=1 if search mode=RL) step, and in step 357, the value of register E2 is incremented by X. Motor driver EL
Upon receiving the shift end signal from D, the microcomputer 4 executes [azimuth scanning JAZS].

In the azimuth scanning JAZS, the received signal level BSs is first read (358), and it is checked whether it is 782 or higher (S59). If it is 782 or higher, the "initial search" is terminated.

If it is less than TH2, it is checked whether the azimuth home position switch 147 is on (home position), and if it is not on, the azimuth position RA2 is at the initial position ("Az data when entering the initial search JS5) x"<
If search mode=RH, X=2. Search mode = R
In the case of L, check whether it is in the left position (one rotation) (562), if not, instruct the driver AZD to shift X5jep to the right, and increment the current azimuth position data A2 by X (562). S64).

Returning to 858 again, the above steps are repeated while monitoring the reception level. When the home position switch 147 is turned on, the antenna is rotated once in the azimuth direction to the left (561). This is to avoid continuous clockwise rotation of two or more rotations.

Azimuth scan (AZS) rotates once in the right direction (from A1 to A
I-X: To be exact, when the clockwise rotation from A1 to A1 becomes one rotation, it returns to 352 and moves to X5te in the elevation direction.
P shift up now.

Reference is now made to Figure 7b. In this way, register E
From the LS elevation position to the position 10° above (if the upper limit is reached by then, the upper limit will be reached), even if the azimuth direction is searched in the first area around the entire circumference, the reception level is B.
If Ss does not become 782 or more, then register ELS
In order to search from the elevation position of 206 to the lower position, first instruct the register ELS to shift downward to the elevation position (365), then in 5sob, the Az data at that time is transferred to registers A1 and A2.
and store the EL data in register E2, ELS-20
is stored in register E1. Then, every time the motor is driven down by X (X=2 in the case of search mode=RH, X=1 in the case of search mode=RL) step in the elevation direction, a search (AZS) in the azimuth direction is performed. In this case, the reception level BSs is read every time it is shifted to the right in the azimuth direction by XNep, and every time it is shifted down by Xs+ep in the elevation direction, and if it is 782 or more, the initial search is ended there, but the register ELS is Even when searching the second small area 120'' from the elevation position, if the reception level BSs does not reach 782 or higher, the 7th c
In the process shown in the right half of the figure (S66 to AZS), the third small area from the elevation position +116 of the register ELS to the upper limit is searched. And even this is 7
If it is not 82 or more, the left half of Figure 7c (S67~A
In the process shown in ZS), the fourth small area from the elevation position -21° of the register ELS to the downward limit is scanned.

If the reception level BSs does not reach 782 or higher even after completing the search for this fourth small area, it means that an appropriate reception level has not been obtained even though the entire range of antenna postures has been searched.

Therefore, in this case, proceed from 554d to 555d and L
``Unreceivable'' is displayed on the CD 23 and the process returns to 53 of the main routine (FIG. 5).

As mentioned above, in "Initial Search JS5,"
The timing of reading the reception level BSs of the receiver BSR is changed in accordance with the reception level BSs in "reception tracking" S14. That is, if the reception level BSs is predicted to be sufficiently large, the reception level BSs of the receiver BSR is read every time the attitude of the antenna Ant is driven two steps in the azimuth direction and the elevation direction (search mode = RH). Since a certain level of reception quality is ensured, the search time can be shortened. Also, reception level B
If it is predicted that Ss will not be obtained sufficiently, each time the attitude of the antenna Ant is driven one step in the azimuth direction and the elevation direction (search mode = RL),
Since the reception level BSs of the receiver BSR is read, high reception quality can be obtained.

"In the initial search JS5, the reception level BSs is the predetermined value 78.
When searching for the attitude of antenna Ant that is 2 or more, the fifth
At 310 in the figure, the microcomputer 4 reads the next reception level BSs, writes it to the register L1, and
After reading Az data and EL data indicating the attitude of nt from the motor drivers AZD and ELD, these data are displayed on the LCD 23.

In 313, the reception level BSs at this time, that is,
The value of register L1 is compared with a predetermined level THI, and as long as the value of register L1 is greater than or equal to the predetermined level THI, S8
→S10→313→513a-=S8→... repeats the loop.

While this is continuing, if the 5TOP key 25 is turned on, this is read in S8 and the process returns to step 33 (standby state) of the flow shown in FIG.

At step 313a, the elevation position data when proceeding there is updated and stored in the register ELS. Therefore, when tracking is stopped in response to turning on the stop instruction key 25 and then executing F initial search J (S5) in response to turning on the start key 24 again, the received level BSs is Since the last elevation position data where THI or more is written, starting from the last elevation position where THI or more is above, the first small area, the second small area, and the 3
Area searches are performed in this order until the small area, the fourth small area, and the TH2H2O mass level are obtained.

When the aforementioned reception level BSs is high and the value of the register L1 becomes less than the predetermined level THI, the microcomputer 4 detects this at 313, proceeds from 313 to 314, and executes "reception tracking" S14. After completing this, further read the reception level BSs (15), and
It is compared with the lower reception lower limit level TH2 (16).

In S16, when the reception level BSs is less than the reception lower limit level 782, the microcomputer 4 proceeds to 517 and reads "
Execute "Tracking Search".

“Receive Tracking” 314 with reference to FIGS. 8a and 8b.
Explain the contents.

First, the concept will be explained with reference to FIG.

FIG. 11 is a conceptual diagram showing a scanning position developed in a plane when the antenna is conically scanned over a minute range.

This conical scanning of a minute range rotates the main beam of the antenna Ant (1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → 1 →
...), and if the target radio wave source is at the center of rotation of the antenna beam, the reception level will be constant over this rotation (scanning), but if the target radio wave source is deviated from the rotation center of the beam, the reception level will be This method takes advantage of the phenomenon in which the maximum value appears as a result of fluctuations during scanning.
), each point 1°2.3,4
, 5, 6.7 and 8 are the projection points 9 and 0 of the main beam (center) of the antenna Ant. 0 is the rotation center of the antenna beam (direction in the attitude just before starting scanning), and the arrow indicates the antenna Ant.
indicates the direction of attitude shift. In addition, RL and RH shown in the figure
indicates a conical scan mode, and RH is a conical scan swing angle (=nical scan radius of rotation) larger than RL (twice in this embodiment). Note that it is assumed that there is an isotropic antenna (isotropic point radio wave source) at point a. Hereinafter, "reception tracking" 514 from a state where the antenna Ant is directed to point 0 will be explained with reference to FIGS. 8a to 8c and FIG. 11.

1) Register C written in the non-volatile memory mentioned above
If the content of 3M is RL, conical scan mode R
Drive the antenna Ant from the starting point 0 to the point 1 by L570-371a-371b-372a-373a),
After storing the reception level at point 1 (584), shift 2 steps in the azimuth direction, shift 1 step downward in the elevation direction, and direct the reception level BSs at point 2 to point 2 (mode RL) 374a). Remember (38
4).

2) First, shift one step to the azimuth direction cloth.

It shifts two steps in the elevation direction to point to point 3 (mode RL) 575a), and stores the reception level at point 3 (384).

3) 6 Next, shift one step to the left in the azimuth direction.

It shifts two steps downward in the elevation direction to point to point 4 (mode RL) 376a), and stores the reception level at point 4 (3+14).

4) Next, shift 2 steps to the left in the azimuth direction.

The signal is shifted one step downward in the direction of the light beam to point 577 to point 5 (mode RL), and the reception level at point 5 is stored (S84).

5) 8th, shift 2 steps to the left in the azimuth direction.

It shifts by one step in the elevation direction to point to point 6 (mode RL) (378i), and stores the reception level at point 6 (Sl14).

6) Next, shift one step to the left in the azimuth direction.

It shifts two steps in the elevation direction to point to point 7 (mode RL) 579a), and stores the reception level at point 7 (384).

7) Next, shift one step to the right in the azimuth direction.

It shifts two steps in the elevation direction to point 8 (mode RL) 580a), and stores the reception level at point 8 (S84).

With the above, ] times of conical scanning (mode RL) are completed,
The reception level BSs of all points (8 points) is in the register FO.
It is written in RI~8.

8), the highest value SPmax among the reception levels of all points
and the lowest value S Pm1n (387a), calculate the difference between the two and check whether the eye difference is within a predetermined range (dTH) (388). If it is within the predetermined range, the There is little variation in reception level, and the antenna Ant
Since the center of is essentially pointing towards the radio wave source, the highest value SP
m1x is less than or equal to the threshold value TH2 for determining poor reception (
If there is no poor reception, the reference value THI for determining good reception is checked (Sl19a).
axXo, updated to 9 (59Qa), this reference value TH
Check whether I is greater than or equal to a certain value HLV (S91
a). If it is above a certain value HLV, the contents of register C3M are set to RH (conical scan mode is set to RH)592
a) If it is less than a certain value HLV, set the contents of register C3M to RL (conical scan mode to RL).
393ri. Note that the contents of this register C3M also set the "initial search JS5 mode" described above in addition to the conical scan mode.

9) Next, find the points (points 1 to 8 in mode RL in FIG. 11) where the reception level is SPmaz (594a to 3).
98).

lO), and the attitude of the antenna Ant is determined so that the center of rotation of the antenna beam is aligned with the point where the received level is the highest, and the process returns (39!l). This results in
When point a shown in Fig. 11 is the position of the radio wave source, the magnitude of the reception level is as follows: point 1> point 2> point 8> point 3> point 7> point 4> point 6> point 5 Therefore, the highest point of reception level is point 1. Therefore, the attitude of the antenna Ant is set so that the directional center of the antenna beam is aligned with point 1.

11) First, in step 91i, the reference value THI
is less than a certain value HLV, the contents of register C3M are R
L (conical scan mode is RL), so (39
3a) The above processes 1) to 10) are repeated, but if the reference value THI is equal to or higher than the fixed value HLV, the register C
The content of 3M becomes RH (conical scan mode is RH) (S92a), and step 371b changes the 8th c
Perform the processing shown in the figure. That is, the antenna Ant is driven from the starting point 0 to the point 1 using the conical scan mode RH.
b) After storing the reception level at point 1 (384), shift the azimuth direction by 4 steps to the right, shift the elevation direction by 2 steps downward to point to point 2 (mode RH) 574b), and store the reception level at point 2. Memorize BSs (
584).

12) First, shift 2 steps to the right in the azimuth direction.

It shifts 4 steps downward in the elevation direction to point to point 3 (mode RH) 575b), and stores the reception level at point 3 (5114).

13) First, shift 2 steps to the left in the azimuth direction.

It shifts 4 steps downward in the elevation direction to point to point 4 (mode RH) 576b), and stores the reception level at point 4 (5114).

14) Next, shift 4 steps to the left in the azimuth direction.

It shifts two steps downward in the elevation direction to point toward point 5 (mode RH) 577b), and stores the reception level at point 5 (384).

15) First, shift 4 steps to the left in the azimuth direction.

It shifts two steps in the elevation direction to point 6 (mode RH) 578b), and stores the reception level at point 6 (384).

16) Next, shift 2 steps to the left in the azimuth direction.

It shifts four steps in the elevation direction to point 7 (mode RH) (579b), and stores the reception level at point 7 (384).

17) First, shift 2 steps to the right in the azimuth direction.

Shift 4 steps upward in the elevation direction to point 8 (
mode RH) (580b), and stores the reception level at point 8 (384).

With this, one conical scan in mode RH has been completed, and the reception levels BSs of all points (8 points) have been written in registers FORI-8.

18), hereinafter, the same processing as shown in 8) to ]0) is performed (S87b to 399), and the antenna An is adjusted so that the center of rotation of the antenna beam is aligned with the point where the reception level is highest.
Set the attitude of t and return.

As described above, in "reception tracking" S14, one cycle of conical scanning of a minute range is performed around the center axis (point 0) of the original antenna beam, the highest point of the reception level is detected, and the highest point of the reception level is detected. The attitude of the antenna Ant is set so that the center axis of the antenna beam is placed at . Therefore, when the radio wave source moves relative to the antenna Ant,
Attitude control is performed in such a manner that the locus of the central axis (point 0) of the antenna beam moves together with the radio wave source, and the antenna Ant tracks the radio wave source. Furthermore, since the deflection angle of the conical scan is varied based on the reception level obtained at that time, the reception quality can be kept constant even if the reception level fluctuates due to the environment (changes in weather, etc.). In other words, when a high reception level is obtained, the deflection angle is increased while maintaining a certain reception quality (conical scan mode = RH), resulting in higher tracking performance, and when only a low reception level is obtained, the deflection angle is increased. Since it is made smaller (conical scan mode=RL), higher reception quality can be obtained.

When the conical scan described above is completed, the reception level is 78.
It does not necessarily have to be 1 or more. When the reception level becomes 781 or higher during conical scanning, it is assumed that there is no pointing error and nothing is done; however, when the reception level does not rise above 782 even after conical scanning,
The microcomputer 4 executes "tracking search" S17.

9a and 9b show the contents of "tracking search" 317, and FIG. 12 shows a schematic diagram for explaining the processing concept of "tracking search" 317.

Referring to these drawings, S]00 is the initial setting, and the state in which the antenna Ant is directed to the dot shown in FIG. 12 is assumed to be when TSC=O.

1) Check whether the TSC value is 4 or less in 5 lots.

As long as the TSC value is 4 or less, proceed to 5102 5102
Check the status of the switch 158, and if it is not on, 51
At 03, the motor driver ELD is instructed to shift up by one step. This is the scan from points 0 to 5 in FIG. If the TSC value is 5 or more in 5101, the process advances to 5104.

2) Check whether the TSC value is 54 or less at 5104. As long as the value of TSC is 54 or less, the process advances to 5105 and instructs the mortar driver AZD to shift right by 1 step. This is the scan from points 5 to 55 in FIG. 51
04 and the TSC value is 55 or more.

Proceed to 3106.

3) Check at 3106 whether the TSC value is 64 or less. As long as the value of TSC is smaller than 65, the process proceeds to step 3107, where the state of the switch 159 is checked, and if it is not on, the step 3108 instructs the motor driver ELD to shift down by one step. This is the scan from points 55 to 65 in FIG. If the TSC value is 65 or more in 3106, the process advances to 3109.

4) Check whether the TSC value is 164 or less at 3109. As long as the value of TSC is 164 or less, the process advances to 3110 and instructs the motor driver AZD to shift left by 1 step. This is the scan from points 65 to 165 in FIG. 5109 and the TSC value is 165 or more, 5i
Proceed to ll.

5) Check whether the TSC value is 174 or less at 5lll. As long as the value of TSC is ]74 or less, proceed to 5112, check the state of the switch 158 in 3112, and if it is not on, take one step to the motor driver ELD in 3113.
Instructs to shift up. This is points 165-17 in Figure 12.
This is a scan up to 5. Sl]1 and the TSC value is 175 or more, the process advances to 5114.

6) Check whether the TSC value is 224 or less at 3114. As long as the value of TSC is 224 or less, the process advances to 5115 and instructs the motor driver AZD to shift right by 1 step. This is points 175-225 in Figure 12 (previous point 5)
This is a scan of If the TSC value is 225 or more in 3114, the process advances to 3116.

7) As long as the value of TSC is 229 or less in 3116, the process advances to 5117, and the state of the switch 159 is checked in 3117, and if it is not on, the motor driver ELD is instructed to shift down by 1 step in 3118. This is point 2 in Figure 12.
25 (previous point 5) to point 230 (previous point 0).

8) When the TSC value is 230 or more in 3116, and when the shift is completed by instructing the shift as described above, execute 5120 to read the reception level, and in 5121 it is 782 or more. If it is 782 or more, the process returns to the main routine (FIG. 5).

If the value is less than 782, the TSC value is updated to a value 1 greater than 3125, and the process proceeds to 5101.

By the above processing of 3101 to 5125, reception level B
Until Ss reaches the second set value TH2 or more, as shown in FIG.
．． 3. ...230(0) in this order, and it is checked whether the reception level is 782 or higher at each point. 23 points with less than 782
When reaching 0 (b=o), that is, returning to the original starting point, the TSC is reset to 0 at 5119,
Since the light is turned on again, the same search scan is performed.

To summarize here, the reception level BSs is
During the above period, it is assumed that there is no pointing error and nothing is done. Reception level BSs is less than THI and 782
If THI is above a certain value HLV, mode RH with a large deflection angle is used, and if THI is less than a certain value HLV, mode RL with a small deflection angle is used. The antenna attitude is changed to . When the reception level BSs is less than the second level TH2, a tracking search (FIG. 12) is performed over a wider range than the conical scan. Also,
Next, "When the initial search JS5 is performed, the search mode is RH if the conical scan mode is RH, and the search mode is RL if the conical scan mode is RL.

From the description of the above embodiments, it can be seen that the present invention applies to moving objects other than road vehicles such as automobiles, trains, etc., that is, ships.

It is easy to understand that it can also be applied to aircraft etc.

In the embodiment described above, the elevation position when the reception level is suitable is written in one area (register ELS) of the internal memory of the computer 4, so when the power of the computer 4 is turned off, the elevation position when the reception level is suitable is written there. Location information disappears.

Therefore, in this case, the midpoint of the entire search area in the antenna elevation direction is written in the register ELS, and searches of small areas are alternately performed from the midpoint. The search area (attitude change area) of the antenna Ant is centered in the elevation direction at the point with the highest setting probability, so the previous good reception point data is stored in the register EL.
When the antenna is not located at S, the antenna search efficiency is high by using the midpoint as the starting point. Note that the computer 4 may be provided with a non-volatile memory and the data of the register ELS may be written therein, or the computer 4 may be provided with a power supply circuit that backs up the power from the onboard battery even when the engine key switch is off. Good too.

In addition, in the embodiment, the contents of the register C3M for setting the search mode and conical scan mode are written to the nonvolatile memory of the computer 4, but even when the engine key switch is off, the computer 4 can be written to the onboard battery power supply. The power supply circuit may be provided with a power supply circuit for bank-up.

〔Effect of the invention〕

As described above, according to the present invention, the first control means (4) refers to the received signal level (BS s ) of the receiver (BSR) and controls the drive means (141, 151) in a direction in which the received signal level (BS s ) increases. Change the attitude of the antenna (An + ). As a result, the antenna (^nt) is adjusted to a posture that provides a good reception level with respect to the radio wave source.

Prior to this attitude correction of the antenna (+1vt), the initial search control means (4) performs the following steps until the received signal level (BSs) of the receiver (BSR) becomes equal to or higher than the set value (TH2).
The antenna (Atu
) is driven stepwise in the elevation direction and azimuth direction. The second control means (
4) is the receiver (BSR) that the first control means (4) refers to.
), the higher the received signal level (BSs), the higher the signal level (search mode = RH), and the lower the signal level (BSs), the lower the signal level (search mode = RO).

Therefore, for example, in the initial search, in an environment where a high received signal level (BSs) can be obtained, the one-step drive amount (direction angle displacement) of the antenna (Ant) is increased.
The time (initial search time) until the received signal level (BSs) of the receiver (BSR) reaches or exceeds the set value (TH2) is substantially shortened, and unnecessary movement of the antenna is reduced.

Furthermore, in an environment where only a low received signal level (BSs) can be obtained, the one-step drive amount (direction angle displacement) of the antenna (An4) is reduced, so that high reception quality can be obtained.

Therefore, even if the reception level of the antenna on the mobile body varies depending on the environment, the reception quality can be kept constant and the reception time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram mainly showing the configuration of an electric circuit section according to an embodiment of the present invention. FIG. 2a is a longitudinal sectional view of the antenna support mechanism of this embodiment. FIG. 2b is an enlarged sectional view taken along line UB-4B of FIG. 2a. FIG. 2 is an enlarged sectional view taken along the line nc-nc in FIG. 2a. FIG. 2d is an enlarged perspective view showing the top surface of the turntable 120 shown in FIG. 2a. FIG. 2e is a perspective view showing the antenna Ant 1 shown in FIG. 2a mounted on an automobile. FIG. 3 is a graph showing the radio wave reception characteristics of the antenna Ant shown in FIG. 2a. FIG. 4 is an enlarged plan view of the operation board 22 shown in FIG. 1. FIG. 5 is a flowchart showing an outline (main routine) of the control operation of the microcomputer 4 shown in FIG. FIG. 6 is a flowchart showing the contents of "manual operation" S4 shown in FIG. Figures 7a, 7b and 7c are similar to those shown in Figure 5.
It is a flowchart which shows the content of initial search JS5. FIGS. 8a, 8b and 8C are shown in FIG.
It is a flowchart which shows the content of reception tracking S14. FIGS. 9a and 9b are flowcharts showing the contents of "tracking search" S17 shown in FIG. FIGS. 10a and 10b are schematic diagrams showing changes in the pointing direction of the antenna Ant according to the initial search JS5 shown in FIGS. 7a, 7b, and 7c. It is a graph showing the amount of attitude change of the antenna Ant due to the "reception tracking" S14 shown in FIGS. 8b and 8c, where the horizontal axis shows the azimuth direction and the vertical axis shows the elevation direction. FIG. 12 is a graph showing the amount of attitude change of the antenna Ant due to the tracking search J 317 shown in FIGS. 9a and 9b, where the horizontal axis shows the azimuth direction and the vertical axis shows the elevation direction. 3: Interface 4: Microcomputer (first control means, second control means, initial search control means) 5: Interface Ant: Antenna (antenna) Conv: BS converter BSR: BS receiver (receiver) BSD: CRT AZD: Azimuth motor driver ELD: Elevation motor driver 10: Azimuth rotation drive mechanism 20: Elevation rotation drive mechanism 22: Operation board 110: Antenna bracket 111.113a, 114a: Angle 112: Bin
113b: Second axis (X) Y: First axis 11
5: Link arm 116: Cylindrical shaft 116a: Ring gear 120h guide hole 117: Pin 118: Split groove 120: Rotating table 120a: Gear 121a: Support arm 122
: Bearing 130: Fixed base 140, reducer 141゛Azimuth drive motor (drive means) 142 Worm 143 Worm wheel 144° gear
145゛Gear shaft 146: Support stand 147 Azimuth home position switch 148: Rotary encoder 150° reducer 151: Elevation drive motor (drive means) 152
: Worm 153, Worm wheel 154: Gear 155: Gear shaft (110~155゛ support mechanism) 157°
Rotary encoder 158: Elevation upper limit switch 159: Elevation upper limit switch 160: Rotary joint 161.162 + cable Figure 2b Figure 20 Figure 2d Figure 20 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7a Figure 9b Figure 10a Search mode = RL Figure 10b Search mode = RH

Claims (1)

[Claims] A support mechanism that rotatably supports the antenna in the elevation direction and the azimuth direction on a moving body; a driving means that rotationally drives the antenna in the elevation direction and the azimuth direction; Receiver; A first control means that refers to the received signal level of the receiver and changes the attitude of the antenna via the drive means in a direction in which the received signal level becomes higher; Changing the attitude of the antenna by the first control means; an initial search control means for driving the antenna stepwise in an elevation direction and an azimuth direction via the driving means until the received signal level of the receiver reaches a set value or more; and the first control means refers to a received signal level of said receiver corresponding to the higher it is;
An attitude control device for an antenna on a moving body, comprising: a second control means that determines a one-step drive amount of the initial search control means, which is smaller when the lower value is lower.