JPH07105655B2 - Attitude control device for mobile antenna - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to attitude control of an antenna on a moving body, and more particularly to designation control of a directional antenna that tracks a radio wave source on the moving body.

[Conventional technology]

For example, a mobile unit such as a vehicle, a ship, or an aircraft (hereinafter referred to as a vehicle) is connected to a fixed station or an artificial satellite station for mobile communication, television broadcast reception, radio broadcast reception, or self-position recognition. An antenna used for communication is installed.

In order to always direct this directional antenna to a prescribed radio wave source or radio wave reflector, conventionally, by conical scan method, etc., the radio wave source is actually received while scanning and driving the antenna, and the radio wave source is searched from the reception level. When a certain reception level is obtained after tracking, the tracking operation is stopped or only the tracking by the continuous robin method is stopped.

[Problems to be Solved by the Invention]

However, if the reception level threshold value for determining the necessity of antenna scanning is set high, the reception level is lower than the threshold value and the antenna scanning continues in bad weather, resulting in unnecessary power consumption and mechanism wear. Bring If the threshold value is low, there is a problem that antenna scanning does not start even if reception can be performed at a higher reception level. There is a demand for an antenna attitude control device that does not perform useless antenna scanning as much as possible in response to changes in the reception level due to changes in the weather, and that performs reception at the highest possible reception level.

An object of the present invention is to automatically avoid a substantially useless automatic tracking operation and receive at a level as high as possible.

[Structure of Invention]

(Means for Solving the Problems) An attitude control device for an antenna on a moving body according to the present invention is an antenna (31, 32) supported on a moving body (CAT) so that its attitude can be changed; ) A drive mechanism (46,57) for changing the attitude of the antenna; reception level detection means (5a, 5b, 5c) for detecting the reception level of the antenna (31,32); and comparing the reception level with a set value. In the attitude control device for an antenna on a moving body, which comprises a control means (1) for setting the antenna attitude via the drive mechanism in a direction in which the reception level is equal to or higher than a set value, the reception level is higher than a reception lower limit level. The second setting value (TH
2) In the above case, the small range scanning control means (1) for scanning the antenna (31, 32) in a small range and setting the attitude of the antenna (31, 32) in the direction in which the receiving level is high during that; When the value is less than the second set value (TH2), a search scan control means (1) for searching and scanning the antenna (31, 32) in a wider range than the scan of the small range; and a reception level during the scan of the small range. Fluctuation (HR-LR) is detected, and when the fluctuation (HR-LR) is less than a third set value (TH3) which is a threshold value for determining whether there is a change, the first set value (TH1) is set to A set value updating means (1) for updating to a value (0.9 · HR) slightly smaller than the high value (HR) of the reception level during the scanning of a small range is provided. The symbols in parentheses are
Corresponding elements or value display symbols are shown in the embodiments described later with reference to the drawings.

(Operation) (I) When the reception level is less than the first set value (TH1) and not less than the second set value (TH2), the small range scanning control means (1)
The antenna (31, 32) is scanned in a small range (Fig. 13), and the attitude of the antenna (31, 32) is set in the direction in which the reception level is high during that period.

As a result, when the reception level exceeds the first set value (TH1), antenna scanning is not performed.

(II) When the reception level falls below the second set value due to an obstacle or the like or a sudden posture change of the vehicle or the like, the search scan control means (1) causes a wider range than the small range scan (Fig. 13). Search the antenna (31, 32) with (Fig. 14)
To do. When the reception level becomes equal to or higher than the second set value (TH2) by this search scanning, the above (I) is obtained. This (II) continues while it is less than the second set value (TH2).

As described above, while the vehicle or the like is moving in a place where there is no obstacle with a relatively slow attitude change, the attitude control of (I) above is performed when the reception level becomes lower than the first set value (TH1). However, when the first set value (TH1) is exceeded, antenna scanning is stopped.

When the orientation of the antenna with respect to the radio wave source deviates relatively largely due to obstacles or because the antenna attitude control cannot respond to a sudden attitude change of the vehicle etc.,
The above control (II) is started and is continued until the reception level is equal to or higher than the second set value (TH2). Therefore, when there is no obstacle or when there is no sudden change in posture of the vehicle or the like, the above (I) is automatically obtained.

In this way, the control of (II) above is a function that automatically detects the change from the unreceivable state to the receivable state and automatically sets the antenna attitude so that it can be tracked by scanning in a small range. Have. With this (II), the continuity of automatic tracking is automatically ensured even when the antenna attitude control speed is slow with respect to a relatively sudden attitude change of the vehicle, etc., so the responsiveness of the antenna attitude control system is improved. Even if it is not particularly expensive, it is possible to realize practically sufficient automatic tracking.

(III) In the above (I), setting value updating means (1)
Detects the fluctuation (HR-LR) of the reception level during a small range of scanning (Fig. 13), and the fluctuation (HR-LR) is the third set value (TH
When it is less than 3), the first set value (TH1) is updated to a value (0.9 · HR) slightly smaller than the high value (HR) of the reception level during the scanning of the small range (FIG. 13).

If the fluctuation (HR-LR) is equal to or greater than the third set value (TH3), it may be possible to receive a higher reception level.
It is also conceivable that the electric field of the radio wave is unstable due to a change of the electric field of the radio wave due to a sudden change of the weather or obstacles during the scanning of a small area. In this case, since the first set value (TH1) is not updated, it is highly likely that the scanning of a small range will be performed again after that, and the antenna attitude will be set in the direction of a higher reception level, or the radio field will be stable. There is a high possibility that the reception level will be detected in the state where

When the fluctuation (HR-LR) is less than the third set value (TH3), the antenna pointing direction at that time is well aligned with the arrival direction of the radio wave and the reception is stable. Since the first setting value (TH1) is updated to a value slightly smaller than the high reception level value at this time, the reliability of the first setting value (TH1) is high. Moreover, the threshold value (TH1) for whether or not to scan the antenna in a small range automatically shifts in synchronization with changes in the reception status, so even if the radio field changes due to changes in the weather, it is useless. Scanning is not performed, and the posture of low-level reception is not maintained when directing to a higher reception level is possible.

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 the appearance of an embodiment of the present invention. In FIG. 1, the CAR is a vehicle (moving body), and an antenna (hereinafter, simply referred to as an antenna) 30 for receiving satellite broadcasting is installed on the roof Rf thereof. In this embodiment, the antenna 30
Uses a commercially available satellite dish for satellite broadcasting.

The antenna 30 will be described with reference to FIGS. 3a and 3b.

First, referring to FIG. 3a, 31 is a parabolic reflector, 32 is BS.
It is a primary radiator integrated with a converter. The parabolic reflector 31 and the primary radiator 32 form a radiation lobe (main lobe: the same applies hereinafter) having a half-value angle of 2 ° at the operating frequency.

A primary radiator 32 (hereinafter referred to as a BS converter) integrated with a BS converter is fixed to a parabolic reflector 31 by supporting arms 33 and 34, and the parabolic reflector 31 is pivotally attached to a support box 35. The support box 35 is fixed to the turntable 38 of the antenna 30 by the frames 36 and 37. The rotary table 38 is rotatably supported by a fixed table 40 via a bearing 39. The fixed base 40 is fixed to a circular recess of the roof Rf of the vehicle CAR, and a weather strip 41 is attached to a contact portion between the roof Rf and the fixed base 38.

Ring-shaped inner teeth 42 are engraved on the rotary table 38, and a gear 43 meshes with the inner teeth 42. The shaft 44 to which the gear 43 is fixed is engaged with the rotation shaft of the azimuth drive motor 46 via a gear box 45. Azimuth drive motor 46
A rotary encoder 47 is coupled to the rotary shaft of the.

Since the azimuth drive motor 46 is fixed to the fixed base 40, when the azimuth drive motor 46 is forwardly biased, it rotates the rotary base 38 to the right when viewed from directly above (Fig. 3b) (clockwise in the azimuth direction). Move),
When it is biased in the reverse direction, the turntable 38 is viewed from directly above (Fig. 3b).
Turn left (turn left in azimuth direction). That is,
The forward rotation bias of the azimuth drive motor 46 causes the radiation lobe of the antenna 30 to face right, and the reverse rotation bias causes the radiation lobe of the antenna 30 to face left. The rotary encoder 47 outputs one pulse each time the attitude of the antenna 30 in the azimuth direction changes by 0.5 °.

Reference numeral 49 denotes a photo interrupter (hereinafter, referred to as an Az sensor) for detecting a home position of the antenna 30 in the azimuth direction, and a light blocking filler provided on the lower surface of the turntable 38 enters at the home position.

A cable 48 connected to an electric element in the support box 35 of the antenna 30 is connected to a fixed side cable (not shown) via a disc-shaped slip ring unit 50.

The electrical cable connected to the output end of the BS converter 32 is
Fixed-side cable via cylindrical rotary joint 51
Connected to 52.

FIG. 3b is a plan view of FIG. 3a seen from directly above, and the inside of the support box 35 will be described with reference to this figure.

A fan gear 54 is fixed to a rotating shaft 53 fixed to the parabolic reflector 31 of the antenna 30. A gear 55 fixed to the output shaft of the gearbox 56 meshes with this gear. The rotation shaft of the elevation drive motor 57 is engaged with the input shaft of the gearbox 56. A rotary encoder 58 is coupled to the rotation shaft of the elevation drive motor 57.

Since the elevation drive motor 57 is fixed to the support box 35, when it is biased in the forward direction, the parabolic reflector 31 and the BS converter 32 and the like are integrally rotated upward (clockwise rotation in FIG. 3a: When it is biased in the reverse direction, the parabolic reflector 31 and the BS converter 32 are rotated upward in the elevation direction.
Etc. rotate downward together (rotate left in FIG. 3a: rotate downward in the elevation direction). That is, the radiation lobe of the antenna 30 faces upward due to the forward drive of the elevation drive motor 57, and the radiation lobe of the antenna 30 faces downward in the reverse posture.
The rotary encoder 58 outputs one pulse each time the attitude of the antenna 30 in the elevation direction changes by 0.5 °. 59U on the back side is antenna 3
This is a limit switch that detects the limit of the elevation angle of 0, and the front side 59D is a limit switch that detects the limit of the depression angle of the antenna 30. Further, reference numeral 60 denotes a photo interrupter (hereinafter referred to as an antenna El sensor) for detecting a home position of the antenna 30 in the elevation direction, and at the home position, a light shielding filler provided on the rotating shaft 53 enters.

In the present embodiment, when the Az sensor 49 and the El sensor 60 detect the home position, the main lobe of the antenna 30 is aligned in the front direction of the vehicle CAR (the traveling direction of the CAR when traveling straight ahead: the same applies hereinafter). Then, it will be parallel to the roof Rf.

FIG. 2a shows the configuration of an electric control system which controls the attitude of the antenna 30.

This control system is a microcomputer (MP
U) It is composed around 1. A read-only memory (hereinafter, ROM) 2, a read / write memory (hereinafter, RAM) 3, a timer 4, and an input / output port (hereinafter, I / O) 5, 6, 7 and 8 are connected to the bus line of MPU1. ing.

The reception level detection unit of the antenna 30 is connected to the I / O. The reception level detection unit is the BS of the antenna 30.
It comprises a converter 32, a distributor 5a, a BS level detector 5b including an amplifier, a frequency converter and a detector, and an A / D converter 5c. The distributor 5a is a BS converter 32 of the antenna 30.
Is distributed to the BS level detector 5b and the BS tuner 5d. The BS level detector 5b detects the level of the received signal and
It is given to the D converter 5c. In response to the instruction from MPU1, the A / D converter 5c digitally converts the level of the signal received by the BS level detector 5b and transfers it to the MPU1.

Further, the BS tuner 5d is connected with a television receiver TV for receiving satellite broadcasting and a radio receiver RD.

A vehicle attitude detection unit is connected to the I / O6. Vehicle attitude detection unit is pitching / rolling angle detection free gyro GYrp, yawing angle detection gyro GYy
a, pitch angle detector 6a, roll angle detector 6b, yaw angle detector 6d
It also consists of gyro drivers 6c and 6e.

The gyro GYrp has a degree of freedom around the pitch axis and the roll axis. The pitch angle detector 6a detects rotation angle data (digital value) around the pitch axis, and the roll angle detector 6b rotates around the roll axis. Detects corner data (digital value).

The gyro GYya has a degree of freedom around the yaw axis, and the yaw angle detector 6d detects rotation angle data (digital value) around the yaw axis.

The gyro drivers 6c and 6d rotationally bias the rotor of the corresponding gyro GYrp or GYya, respectively.

An operation board 22 is connected to the I / O7. Operation board 22
Is installed on the console board in the car CAR, and its appearance is shown in Fig. 4.

Referring to FIG. 4, this operation is performed on the board 22 with the azimuth data (hereinafter referred to as azimuth data) of the antenna 30 and the elevation (depression).
Small CRT display 23 for displaying angle data (hereinafter elevation data), reception level, and various messages, start (START) key 24 for instructing automatic attitude control of antenna 30, instructing to stop automatic attitude control of antenna 30 A stop key 25, an up key (U key) 26 for manual attitude control, a down key (D key) 27, a right key (R key) 28, and a left key (L key) 29 are provided.

Inside the operation board 22, a key encoder for reading the operation of these keys in response to the instruction of the MPU1 and a CR
CRT for displaying various messages on T display 23
It has a driver.

A motor control unit 10 including an azimuth drive motor 46, an elevation drive motor 57, etc. is connected to the I / O 8.

The structure of the motor control unit 10 is shown in FIG. 2b.

Referring to FIG. 2b, the motor control unit 10
Is a microprocessor (hereinafter CPU) 10a, an azimuth unit AzU, an elevation unit ElU, an input buffer 18, and the like.

The azimuth unit AzU is a D / A converter 11a, power amplifier 12a, base drivers 13a, 14a, waveform shaping circuit 15a, up / down counter 16a, parallel out / serial in shift register (PS register) 17a, azimuth drive motor. 46, rotary encoder 47, power transistor
It is composed of Tr1a, Tr2a, Tr3a and Tr4a.

The elevation unit ElU includes a D / A converter 11b, a power amplifier 12b, base drivers 13b and 14b, a waveform shaping circuit 15b,
It is composed of an up / down counter 16b, a PS register 17b, an elevation drive motor 57, a rotary encoder 58, power transistors Tr1b, Tr2b, Tr3b and Tr4b.

In the input buffer 18, the Az sensor 49, El sensor 60,
Limit switches 59U and 59D are connected.

The CPU 10a responds to the instruction from the MPU 1 and responds to the motors 46 and 57.
Is subjected to forward / reverse urging control at a designated speed to read the azimuth attitude data (angle) and elevation attitude data (angle), and the states of the limit switches 59U and 59d, and transfer them to the MPU1.

Since the azimuth unit AzU and the elevation unit ElU have the same configuration although there are slight differences in the specifications of the components, the azimuth unit AzU will be described here.

For the D / A converter 11a of the azimuth unit AzU, the CPU10a
From the output port P1 of 1, the voltage data corresponding to the energizing speed of the motor 46, which is instructed from the MPU 1, is given. The D / A converter 11a outputs a voltage corresponding to this voltage data and applies it to the power amplifier 12a. The power amplifier 12a is
The output voltage of the D / A converter 11a is converted into the drive voltage of the motor 46 and applied to the collectors of the power transistors Tr1a and Tr3a. The emitter of the power transistor Tr1a is connected to the collector of the power transistor Tr4a, the emitter of the power transistor Tr3a is connected to the collector of the power transistor Tr2a, and the emitters of the power transistor Tr4a and the power transistor Tr2a are grounded. The bases of the power transistors Tr1a and Tr2a are connected to the output terminal of the base driver 13a, and the bases of the power transistors Tr3a and Tr4a are connected to the output terminal of the base driver 14a. Base driver 13
The input terminal of a is connected to the output port P2 of the CPU 10a, the input terminal of the base driver 14a is connected to the output port P3 of the CPU 10a, and the CPU 10a outputs from the output port P2 when energizing the motor 46 in the forward direction. The H level (high level) is output and the power transistors Tr1a and T1 are supplied to the base driver 13a.
The r2a is instructed to be turned on, the output port P3 outputs an L level (low level), and the base driver 14a is instructed to turn off the power transistors Tr3a and Tr4a.
When biasing 46 in the reverse direction, an L level is output from the output port P2 and the power transistor Tr1a is output to the base driver 13a.
And Tr2a are instructed to be turned off, and an H level is output from the output port P3 to instruct the base driver 14a to turn on the power transistors Tr3a and Tr4a. When the motor 46 is deenergized, the output ports P2 and P3 are turned on. The L level is output to instruct the base drivers 13a and 14a to turn off the power transistors Tr1a, Tr2a, Tr3a and Tr4a.

Since the motor 46 is inserted on the line connecting the connection point between the power transistors Tr1a and Tr4a and the connection point between the power transistors Tr2a and Tr3a, the power transistors Tr1a and Tr2a are turned on and the power transistors Tr3a and Tr3a When Tr4a is turned off, a forward rotation energizing circuit composed of the output of power amplifier 12a, power transistor Tr1a, motor 46, power transistor Tr2a and ground is configured, and forward rotation energization is performed at the voltage set by D / A converter 11a. The power transistors Tr1a and Tr2a are turned off.
When Tr3a and Tr4a are turned on, a reverse biasing circuit consisting of the power amplifier 12a output, power transistor Tr3a, motor 46, power transistor Tr4a, and ground is configured, and the reverse biasing voltage is set by the D / A converter 11a. To be done.

The output of the rotary encoder 47 is waveform-shaped by the waveform shaping circuit 15a and applied to the input port R1 of the CPU 1a and the input terminal In of the up / down counter 16a. The up-down counter 16a counts up at the rising edge of the pulse applied to the input terminal In when the U terminal is at the H level and the D terminal is at the L level, and the U terminal is at the L level and the D terminal is at the H level. Input terminal when level is given
Counts down at the rising edge of the pulse given to In. This counter 16a is a 720-ary counter (10 bits), and when the value is 719 and it counts up, the value becomes 0,
When the value is 0, the countdown is 719.

The reset input terminal Rst of the up / down counter 16a is CPU1
It is connected to the output port P4 of 0a, and the 10-bit parallel output terminal is connected to the parallel input terminal of the PS register 17a. The shift load input terminal SL of the PS register 17a is given from the shift load pulse from the output port P5 of the CPU 10a, the clock inhibit input terminal CI is given the clock inhibit signal from the output port P6 of the CPU 10a, and the clock input terminal CK is given. A clock pulse is given from the output port P7 of the CPU 10a.

The PS register 17a presets the data given to the parallel input terminal to each bit at the rising edge of the shift load pulse, and outputs the preset data in synchronization with the clock pulse from the output terminal OUT when the clock inhibit signal shifts to the H level. Serial output to the serial input port R2 of the CPU 10a.

Referring again to FIG. 2a, the power supply of this system is the on-board battery BAT, and the constant voltage Vc and V are supplied from the constant voltage circuit Reg via the Acc switch (accessory mode switch).
s is supplied to each part. The constant voltage Vc mainly serves as a power source for each part of the electric control system, and the constant voltage Vs serves mainly as a power source for driving the motor and the gyro.

Next, the antenna attitude control of the embodiment apparatus brought about by the above configuration and the control operation of the MPU 1 and the CPU 10a will be described.

The flowcharts shown in FIGS. 5a and 5b show the main routine of the MPU 1, and the flowchart shown in FIG. 10 shows the main routine of the CPU 10a. In the following description, "S-" indicates a number assigned to each step in the flowchart ("S" is omitted in the flowchart).

Referring to FIG. 5a, when the Acc switch is turned on and a predetermined voltage is supplied to each unit, the MPU1 resets each input / output port, internal register, flag, RAM3, etc. in S1 and initializes and receives. The standard value TH1s of the first set value is stored in the register TH1 which stores the first set value which is higher than the second set value which is the lower limit level and which is the threshold value for judging the high and low of the reception level. Of the CPU10a in S2
Configure a loop that waits for a Ready signal.

Referring to FIG. 10, at this time, in the CPU 10a, the input / output port, the internal register and the like are reset and initialized, and then the initialization is executed. By default, antenna 30
Is set to the home position in the azimuth direction and the elevation direction. That is, the motor 46 is normally biased to search for an azimuth direction posture in which the Az sensor 49 is turned on, and then the motor 57 is normally biased to find the elevation direction posture in which the El sensor 60 is turned on. While searching, the attitude of the antenna 30 in the elevation direction becomes the elevation angle limit during searching, and when the limit switch 59U is turned on,
The motor 57 is biased in the reverse direction to search for an attitude in the elevation direction in which the El sensor 60 is turned on. CPU10a is antenna 30
Counters 16a and 1 when the home position in the azimuth direction and elevation position is completed.
6b is reset and a Ready signal is output to MPU1. After this, 1step right shift processing, 1step left shift processing, 1step up shift processing, 1st according to the instruction mode from MPU1
ep Down shift processing, right shift processing, left shift processing, up shift processing, down shift processing, or stop processing is executed. These processes will be described later.

When MPU1 receives Ready signal from CPU10a, START key
A loop that executes the manual operation process of S4 is configured until 24 is turned on.

The manual operation process will be described with reference to the flowchart shown in FIG. When the U key 26 is operated, the MPU1 will move to S3
Proceed from 0 to S31 to check the state of the limit switch 59U. Antenna 30 if switch 59U is on
The posture in the elevation direction is at the limit of elevation angle, and further upward drive is impossible, but otherwise S32
Then, the CPU 10a is instructed to execute the shift process by one step. When the D key 27 is operated, the process proceeds from S33 to S34, where the state of the limit switch 59D is checked. If the switch 59D is turned on, the attitude of the antenna 30 in the elevation direction is at the limit of the depression angle, and further downward drive is impossible, but if not so, the CPU T10a in S35 is shifted down one step. To execute.

If the R key 28 is operated, the MPU 1 will move from S36 to S37.
If the CPU 10a is instructed to execute the 1step right shift process and the L key 29 is operated, the process proceeds to S38 to S39.
Then, the CPU 10a is instructed to execute the 1step left shift treatment.

In response to such a 1-step driving instruction of the MPU 1, the 1-step right shift processing executed by the CPU 10a is shown in FIG. 11, the 1-step left shift processing is shown in FIG. 11b, the 1-step upper shift processing is shown in FIG.
The lower shift processing is shown in FIG. 11d, respectively.

The 1-step right shift processing will be described with reference to FIG. 11a.
The U10a outputs the voltage data corresponding to the maximum speed of the motor 46 from the output port P1 and gives it to the D / A converter 11a, and outputs the H level from the output port P2 and the L level from the P3 to the base driver 13a. The power transistors Tr1a and Tr2a are turned on, the base driver 14a is instructed to turn off the power transistors Tr3a and Tr4a, and the up-down counter 16a is instructed to up-count. Thereafter, when the motor 46 rotates in the forward direction and the output pulse of the rotary encoder 47 via the waveform shaping circuit 15a is detected at the input port R1, the L level is output from P2 and the power transistors Tr1a and Tr2a are output to the base driver 13a. The off driving of the motor 46 is instructed to deactivate the motor 46. That is, 1step
In the right shift processing, the posture of the antenna 30 in the azimuth direction is shifted by one step, that is, 0.5 ° to the right.

Similarly, in the 1-step left shift processing shown in FIG. 11b,
The CPU 10a shifts the azimuth direction attitude of the antenna 30 to the left by 0.5 ° (one step), and then shifts it to the 1st position shown in FIG. 11c.
In the ep upshift processing, the antenna 30 attitude in the elevation direction is shifted upward by 0.5 ° (one step), and in the 1step downshift processing shown in Fig. 11d, the antenna 30 attitude in the elevation direction is 0.5 °. (Down one step) Shift down.

When the CPU 10a completes the 1-step right shift process (Fig. 11a), 1-step left shift process (Fig. 11b), 1-step up shift process (Fig. 11c) or 1-step down shift process (Fig. 11d), it indicates the end of shift. The signal, the attitude data in the azimuth direction (Az data) and the attitude data in the elevation direction (El data) are transferred to the MPU1.

Referring again to FIG. 6, the MPU 1 determines that the CPU 10a in S40
The CPU waits for execution of 1 step right shift processing, 1 step left shift processing, 1 step up shift processing or 1 step down shift processing by, and reads the Az data and El data transferred in S41. Further, in S42, the reception level is read and stored in the register L1, and in S43, the Az data, El data and the reception level of the register L1 are displayed on the CRT 23.

MPU1 is STA on S3A in S3A, S4 and S5 (Fig. 5a)
When the RT key 24 is detected to be turned on, it is checked in S3B whether the reception level is equal to or higher than the second setting value TH2 which is the reception lower limit level, and if not, the initial search process shown in FIG. 7 is executed in S5.

The contents of the initial search process S5 will be described with reference to FIG. 7. First, the concept of the initial search process S5 will be described with reference to FIG. In this, while monitoring the reception level, the attitude of the antenna 30 in the elevation direction is repeatedly shifted up by one step from the lower limit position (depression angle limit) to the upper limit position (elevation angle limit). The posture of the antenna 30 is shifted to the right one step, and this time the lower shift is repeated from the upper limit position to the lower limit position. When the lower limit position is reached, the posture of the antenna 30 in the azimuth direction is shifted to the right one step, and the above is received. Is repeated over the entire circumference until it reaches a level sufficient for reception (actually, one step is 0.5 °, so it is much thinner than in FIG. 12).

More specifically referring to FIG. 7, in S50, the Az data at that time is stored in the registers A1 and A2, and the El data is stored in the registers E1 and E2.
The flag F1 is reset (0) with. The flag F1 is a flag for setting the shift direction (up / down) in the elevation direction.

After that, the reception level is read in S52 and the value is stored in the register L1. When the reception level at this time, that is, the value of the register L1 is the second set value TH2 or more, the MPU1
Returns from S53 to the main routine immediately,
If it is less than the second set value TH2, proceed to S54 and below
Make 30 posture changes. In this change, first, when the flag F1 is reset (0), the limit switch 59U
If is not on, proceed to S54 → S55 → S56, where CPU10
Instruct a to execute the above-mentioned 1-step upward shift processing, and increment the value of the register E2 by 1 in S57. Upon receiving the shift end signal from the CPU 10a, the MPU 1 returns to S52 again and repeats the above while monitoring the reception level. If the switch 59U is turned on before the reception level becomes equal to or higher than the second set value TH2, the flag F1 is set (1) in S58, the CPU 10a is instructed to execute the 1-step right shift process in S59, and the register is executed in S60. Increment the value of A2 by 1 (However, register A2
When the value of is 720, it is set to 0).

After setting (1) the flag F1, the process proceeds to S54 → S61 → S63, in which the CPU 10a is instructed to execute the above-mentioned 1-step lower shift processing, and the value of the register E2 is decremented by 1 in S64.
If the switch 59D is turned on before the reception level becomes equal to or higher than the second set value TH2 by repeating this process, the flag is set in S62.
F1 is reset (0), the CPU 10a is instructed to execute the 1-step right shift processing in S59, and the value of the register A2 is incremented by 1 in S60 (however, it is set to 0 when the value of the register A2 becomes 720). ).

While the above processing is repeated, the reception level is the second set value TH.
When it becomes 2 or more, the process returns to the main routine, but when the attitude of the antenna 30 starts the initial search process before the reception level becomes 2nd setting value TH2 or more, that is,
When the value of register A2 becomes equal to the value of register A1 and the value of register E2 becomes equal to the value of register E1, respectively, S66 to S67.
Proceed to and display "Unable to receive" on the CRT 23, and return to S3 of the main routine.

In the initial search process S5, when the attitude of the antenna 30 in which the reception level becomes equal to or higher than the second set value TH2 is searched, the gyro data is set in S6 of FIG. 5a. In this process, S6a
After storing the yaw angle data from the yaw angle detector 6d in the register Ry, the roll angle data from the roll angle detector 6b in the register Rr, and the pitch angle data from the pitch angle detector 6a in the register Rp. , S6b is converted into data in the azimuth direction and data in the elevation direction of the antenna 30 by using the conversion matrix (A) (in S6b of the flowchart, description of higher order terms is omitted). This conversion operation is executed by referring to the conversion table stored in ROM2. The converted gyro data in the azimuth direction is stored in the register Ra1, and the converted gyro data in the elevation direction is stored in the register Re1.

When gyro data is set in S6, the T1 timer (internal timer) is cleared and started in S7.

Next, referring to FIG. 5b, in the motor energization parameter setting process of S9, the MPU 1 first registers the register Ra1 in S9a.
The gyro data in the azimuth direction stored in the register Ra2 is saved in the register Ra2, and the gyro data in the elevation direction stored in the register Re1 is saved in the register Re2.
Then, in S9b, the gyro data set process equivalent to the process in S6 is performed, and the azimuth and elevation values are detected from the yaw angle data (Ry), roll angle data (Rr), and pitch angle data (Rp) detected at that time. Gyro data in the direction of the motion is obtained and stored in registers Ra1 and Re1 respectively. In S9c, the difference between registers Ra2 and Ra1 is calculated by register Ra3.
Then, the difference between the registers Re2 and Re1 is stored in the register Re3. That is, the values of the registers Ra3 and Re3 indicate the amount of change in the gyro data since the gyro data set process was performed before that. Since the T1 timer measures the time during this gyro data setting process, the value obtained by dividing the value of the register Ra3 by the value of the T1 timer indicates the displacement speed in the azimuth direction (the sign is the direction), The value obtained by dividing the value of the register Re3 by the value of the T1 timer indicates the displacement speed in the elevation direction (the sign is the direction). Therefore, in S9d, the urging speed and the urging direction of the motors 46 and 57 are calculated from these values, and the urging speed and the right / left shift or the up / down shift are instructed to the CPU 10a. This calculation is performed by referring to the table stored in ROM2.

When the MPU 1 instructs the right shift, the CPU 10a displays the 11e
As shown in the figure, the output port P1 outputs the voltage data corresponding to the instructed speed, the output port P2 outputs the H level to instruct the base driver 13a to turn on the power transistors Tr1a and Tr2a, and the output port P3. Output L level from the power transistor Tr3 to the base driver 14a.
When a and Tr4a are instructed to be turned off and left shift is instructed, voltage data corresponding to the instructed speed is output from the output port P1 and output port P2 as shown in FIG. 11f.
From the output port P3 to instruct the base driver 13a to turn off the power transistors Tr1a and Tr2a, and to output to the base driver 14a to turn on the power transistors Tr3a and Tr4a.
When the upshift is instructed, as shown in FIG. 11g, the output port P8 outputs voltage data corresponding to the instructed speed, and the output port P9 outputs the H level to output power transistors Tr1b and Tr2b to the base driver 13b. To drive the power transistors Tr3b and Tr4 to the base driver 14b.
When the OFF drive of b is instructed and the down shift is instructed, the voltage data corresponding to the instructed speed is output from the output port P8 and the L level is output from the output port P9, as shown in FIG. 11h. Command the base driver 13b to turn off the power transistors Tr1b and Tr2b, and
The H level is output from P10 to instruct the base driver 14b to turn on the power transistors Tr3b and Tr4b.

In the next S9e, MPU1 clears and starts the T1 timer.

The MPU1 reads the reception level at the next S10 and the antenna at S11.
After reading the Az data and El data indicating the postures of 30, these data are displayed on the CRT 23 in S12.

(0) In S13, the reception level at this time, that is, the value of the register L1 is compared with the first set value TH1 of the register TH1, and as long as the value of the register L1 is equal to or more than the first set value TH1, S
The loop of 8 → S9 → S10 → S11 → S12 → S13 → S8 → ... Is repeated to execute the attitude control process (0) of the antenna 30 based on the gyro data. That is, while the reception level is equal to or higher than the first set value TH1, if the gyro data changes, the attitude of the antenna 30 is corrected by an amount corresponding to the change. If the STOP key 2 is turned on while continuing this, it is read in S8 and the flow shown in FIG.
Return to S3 (standby state).

In the loop (S8 to S13), in which the reception level is high and the control for changing the attitude of the antenna 30 in association with the change based on the gyro data is performed at the reception level,
That is, when the value of the register L1 becomes less than the first set value TH1, the MPU1 detects this in S13 and proceeds from S13 to S14.
Further, the value of the register L1 is compared with the second set value TH2 which is the reception lower limit level and the reception lower limit level. In S14, register L1
When the value of is equal to or higher than the second set value TH2 which is the reception lower limit level, the MPU 1 proceeds to S15 and executes the reception tracking process.

(I) The reception tracking process will be described with reference to FIG. 8. First, the concept will be described with reference to FIG. Figure 13 shows
It is the conceptual diagram which developed the scanning position at the time of carrying out the conical scanning of a minute range on the antenna. This conical scanning in a minute range rotates the main beam of the antenna 30 (1 → 2 → 3 →
4 → 5 → 6 → 7 → 8 → 1 → ...) and the target radio wave source is at the center of rotation of the antenna beam, the reception level becomes substantially constant during scanning, but the target radio wave source is This utilizes a phenomenon in which the reception level fluctuates during scanning and the maximum value appears when the center of rotation deviates. In Fig. 13, the squares indicate one step (0.5 °) in the elevation direction (U / D) and 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 30, point 0 is the center of rotation of the antenna beam, and arrows indicate the shift direction of the attitude of the antenna 30. It is also assumed that the point a has an isotropic antenna (isotropic point radio wave source). Hereinafter, the reception tracking process from the state where the antenna 30 is directed to the point 0 will be described with reference to FIGS. 8 and 13.

1). Drive the antenna 30 from the starting point 0 to the point 1 (S70 to S7
3) After memorizing the reception level at point 1 (S84), point to point 2 as a 2-step shift to the right in the azimuth direction and a 1-step shift downward in the elevation direction (S74), point 2
The reception level of is stored (S84).

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

3). Then, it is shifted one step to the left in the azimuth direction and two steps downward in the elevation direction to point to point 4 (S76), and the reception level at point 4 is stored (S84).

4. Next, shift 2 steps to the left in the azimuth direction and shift 1 step downward in the elevation direction to point 5 (S7
7) The reception level at point 5 is stored (S84).

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

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

With the above, one conical scan is completed, and all the points (8
The reception level of (point) is written in the registers POR1 to POR8.

8). Next, the reception levels from point 1 to point 8 are compared, and the maximum value (HR) of the reception level and that point (HP) and the minimum value (LR) and that point (LP) are obtained (S87 to 90H, L, 91).

9. Next, in S92, the left HR-LR of the maximum value HR and the minimum value LR is less than the third set value TH3 which is the threshold value for determining the presence or absence of the reception level fluctuation during the above-mentioned conical scanning. Is checked, and if the maximum value HR is greater than or equal to the second set value in S93, and both are established, the first value is determined in S94.
Set value TH1 (content of register TH1) is detected maximum value HR
Is updated to a value obtained by multiplying 0.9 by 0.9, and the attitude of the antenna 30 is determined so that the rotation center point of the antenna beam is aligned with the obtained point HP of the maximum value HR (S95).

The difference between the maximum value HR and the minimum value LR in S92 is HR-LR is the third set value TH3.
In the above case, or when the maximum value HR is less than the second set value TH2, the first set value TH1 is not updated and the calculated maximum value HR is obtained.
The posture of the antenna 30 is determined so that the rotation center point of the antenna beam is aligned with the point HP (S95).

When point a shown in FIG. 13 is the position of the radio wave source,
The size of the reception level is point 1> point 2> point 8> point 3> point 7
Since> point 4> point 6> point 5, the highest point of the reception level is point 1. Therefore, the posture of the antenna 30 is set so that the directional center of the antenna beam is aligned with the point 1.

As described above, in the reception tracking processing S15, the conical scanning of a minute range of one cycle is performed around the center axis (point 0) of the original antenna beam to detect the highest reception point,
Antenna 30 so that the central axis of the antenna beam is placed there
Set the posture of. Therefore, when the radio wave source moves relative to the antenna 30, the attitude control is performed in such a manner that the locus of the central axis (point 0) of the antenna beam moves with the radio wave source, and Tracking is performed.

When the above-mentioned one-time conical scanning and attitude setting (I) are completed, the reception level is not always TH1 or higher. Reception level is TH1 with conical scanning and attitude setting (I)
When it becomes the above, the above-mentioned attitude control (0) is executed, but when the reception level does not become TH1 or more even by the conical scanning and the attitude setting (I), the MPU 1 makes the fifth
The subroutine of motor attitude parameter setting (S9) shown in Fig. b is executed, and through S10 to S13, reception tracking (S9) starts again from S13.
15; FIG. 8) That is, another conical scan and attitude setting (I) are executed once again. Since the motor parameter set of S9 is executed between the preceding conical one scan and the following conical one scan, when the conical scan is repeated, the center position (0 in FIG. 13) is changed to the posture change of the vehicle. Correspondingly shift. In other words, the antenna attitude automatically shifts in response to changes in the vehicle attitude even during repeated conical scanning.

(III) The antenna is oriented in the optimum direction (TR-LR is TH3
However, if the reception level decreases, S94
Since the first set value TH1 is updated to 0.9 times the detected maximum value (sequentially lowered), the conical scanning does not continuously stop when the reception level decreases due to weather or the like. That problem disappears. When the weather recovers and the reception level rises, the first set value TH1 rises in conjunction with it, so that a poor reception state in which the antenna attitude does not change while the low level reception is maintained can be avoided.

(II) Please refer to FIG. 5b again. In S14, when the reception level is less than the second setting value TH2 which is the reception lower limit level, the process proceeds to S16 and the tracking search process is executed.

FIG. 9 shows a flowchart of the tracking search process, and FIG. 14 shows a schematic diagram for explaining the concept of the tracking search process. The contents of the tracking search process of S16 will be described with reference to these drawings. S100 is an initial setting, and the state in which the antenna 30 is directed to the point b shown in FIG. To do.

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 switch 59U in S102.
Check the state of, and if it is not on, 1 step to CPU 10a in S103
Instruct to execute the upper shift processing. This is point 0 in Fig. 14.
Up to 5 scans. When the TSC value is 5 or more in S101, the process proceeds to S104.

2) In S104, check whether the TSC value is 54 or less. As long as the value of TSC is 54 or less, the process proceeds to S105, and the CPU 10a is instructed to execute the 1-step right shift process. This is the scan from points 5 to 55 in FIG. If the TSC value is 55 or more in S104, ST106
Go to.

3) Check whether the TSC value is 64 or less in S106. As long as the value of TSC is less than 65, the process proceeds to S107, the state of the switch 59D is checked in S107, and if not ON, the CPU 10a is instructed to execute the 1-step downshift process in S108. This is points 55 to 65 in Fig. 14.
Up to the scan. If the TSC value is 65 or more in S106, S
Continue to 109.

4) In S109, check whether the TSC value is 164 or less. As long as the TSC value is 164 or less, the process proceeds to S110, and the CPU 10a is instructed to execute the 1-step left shift process. This is the scan from points 65 to 165 in FIG. If the TSC value is 165 or higher in S109, S1
Proceed to 11.

5) In S111, check whether the TSC value is 174 or less. As long as the TSC value is 174 or less, proceed to S112 and switch 59U in S112.
Check the state of, and if it is not on, 1 step to CPU 10a in S113
Instruct to execute the upper shift processing. This is point 165 in Fig. 14.
~ 175 scans. When the TSC value is 175 or more in S111, the process proceeds to S114.

6) In S114, check whether the TSC value is 224 or less. As long as the value of TSC is 224 or less, the process proceeds to S115, and the CPU 10a is instructed to execute the 1-step right shift process. This is point 175 to 225 in Fig. 14.
This is the scanning of (point 5 above). When the TSC value is 225 or more in S114, the process proceeds to S116.

7) As long as the value of TSC is less than 229 in S116, proceed to S117
Check the state of switch 59D with 117, and if it is not on, S118
Then, the CPU 10a is instructed to execute the shift processing of 1 step down. This is the scanning from the point 225 (the previous point 5) to the point 230 (the previous point 0) in FIG.

8) When the value of TSC is 230 or more in S116, and when the shift process is instructed as described above and the shift process is completed, S120 is executed to read the reception level,
In S121, it is checked whether it is TH2 or more, and when it is TH2 or more, the process returns to the Mayroutine (Fig. 5b). If it is less than TH2, execute the motor energizing parameter set of S122 (this content is the same as the content of S9 in Fig. 5b), read the reception level again in S123, and check if it is the second set value TH2 or more in S124. Check, and if TH2 or more, return to the main routine, but if less than TH2, set the TSC value to 1 in S125.
Update to a larger value and proceed to S101.

By the above processing of S101 to S125, until the reception level becomes equal to or higher than the second set value TH2, as shown in FIG.
Starting from (0), a search scan is performed along a locus that traces points 1, 2, 3, ... 230 (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 230 (b = 0) while it is less than TH2, that is, when it returns to the original start point, TSC is reset to 0 in S119, and the same search scanning is performed from the point b.

Even during such a search scan, each time each point is reached,
Since the motor energizing parameter set is executed in S122 and the posture change corresponding to the change in the detected value of the gyro is executed, the position of the base point (b = 0) does not change while the bill of the vehicle does not change. If there is a change in the attitude of the vehicle, the base point automatically shifts accordingly, but the search scanning range (Fig. 14) with respect to the base point does not change.

While the electric wave is blocked by the obstacle, the above-described search scanning is repeated, and if the posture of the vehicle is changed during that time, the base point of the search scanning 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: Fig. 14), and the search scanning of the locus shown in Fig. 14 is repeated until the radio wave is received. If there is a change in the posture of the vehicle in the meantime, the base point shifts in conjunction with it.

Even when the antenna tracking (0) and (I) cannot be performed in time and the reception level drops below TH2 due to a relatively abrupt posture change of the vehicle, the above search scan (I
I) is executed.

From the above description of the embodiments, it can be easily understood that the present invention can be applied to a moving body other than a road vehicle, that is, a ship, an aircraft or the like.

〔The invention's effect〕

Like the conventional tracking device, when the comparison level TH1 is fixed when it is fixed and the reception level is compared with this to determine the necessity of antenna scanning in a small range, if the maximum reception level changes due to changes in the weather, When TH1 is high, scanning does not stop continuously during bad weather, and when TH1 is low, low low level despite high reception without scanning when weather is good. The antenna will be maintained in the receiving posture of.

According to the present invention, by changing the value of the first set value TH1 which is the threshold value for judging the high or low of the reception level according to the magnitude of the fluctuation of the reception level during the scanning of the small range, the bad weather condition can be improved. When the (reception level is low), a low value is automatically set, and when the weather is good (reception level is high), a high value is automatically set to eliminate the conventional inconvenience. this is,
It effectively controls the small-range scanning when it is effective, and otherwise stops the small-range scanning, which wastes unnecessary power and accelerates wear of the mechanism. The problem is solved, and there is a benefit that the reception is always performed at the highest level possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention. FIG. 2a is a block diagram showing the electrical configuration of the antenna attitude control system of one embodiment of the present invention, and FIG. 2b is a block diagram showing details of the motor control unit 10 shown in FIG. 2a. 3a and 3b are partial sectional views showing the structure of the antenna 30 shown in FIG. FIG. 4 is a plan view showing the appearance of the operation board 22 shown in FIG. 5a, 5b, 6, 7, 8 and 9 are flowcharts showing the operation of the microcomputer 1 shown in FIG. 2a. Fig. 10, Fig. 11a, Fig. 11b, Fig. 11c, Fig. 11d, Fig. 11e
FIG. 11, FIG. 11f, FIG. 11g and FIG. 11h are flowcharts showing the operation of the microprocessor 10a shown in FIG. 2b. FIG. 12 is a schematic diagram for explaining the concept of the initial search process executed by the microcomputer 1 shown in FIG. 2a. FIG. 13 is a schematic diagram for explaining the concept of the reception tracking process executed by the microcomputer 1 shown in FIG. 2a. FIG. 14 is a schematic diagram for explaining the concept of the tracking search process executed by the microcomputer 1 shown in FIG. 2a. 1: Microcomputer (small range scanning control means, search control means, set value updating means) 2: Read-only memory, 3: Read / write memory 4: Timer, 5,6,7,8: I / O port 5a: Distributor, 5b: BS level detector 5c: A / D converter, 5d: BS tuner (5a to 5c: reception level detecting means) 6a: Pitch angle detector, 6b: Roll angle detector 6c, 6e: Gyro driver, 6d: Yaw Angle detector 10: Motor control unit 10a: Microprocessor, 11a, 11b: D / A converter 12a, 12b: Power amplifier, 13a, 13b, 14a, 14b: Base driver 15a, 15b: Wave shaping circuit, 16a, 16b: Up-down counter 17a, 17b: Parallel-in / serial-out shift register 18: Input buffer, 22: Operation board 23: CRT display, 24, 25, 26, 27, 28, 29: Operation key 30: Satellite broadcasting reception antenna , 31: Parabolic reflector 32: Primary radiator integrated with BS converter (31, 32: Antenna) 33, 34: Support Holding arm, 35: Support box 36, 37: Frame, 38: Rotating table 39: Bearing, 40: Fixed table 41: Weather strip, 42: Internal teeth 43, 55: Gear, 44: Shaft 45, 56: Gear box, 46: Azimuth drive motor 47,58: Rotary encoder, 48: Cable (46,57: Drive mechanism) 49,60: Photo interrupter, 50: Slip ring unit 51: Rotary joint, 52: Fixed side cable 53: Rotating shaft, 54: Fan gear 57: Elevation drive motor 59U, 59D: Limit switch, CAR: Vehicle (moving body) Rf: Roof, TV: Television receiver RD: Radio, GYrp, GYya: Gyro Acc: Accessory mode switch Reg: Constant voltage circuit, BAT: Vehicle battery AzU: Azimuth unit, ElU: Elevation unit

Claims (1)

[Claims] 1. An antenna supported on a moving body so that its attitude can be freely changed; a drive mechanism for changing the attitude of the antenna; a reception level detecting means for detecting the reception level of the antenna; and the reception level. An attitude control device for an antenna on a moving body, comprising: a control unit that sets an antenna attitude via a drive mechanism in a direction that is greater than or equal to a set value compared to a set value, wherein the reception level is higher than a reception lower limit level. When it is less than 1 set value and more than the 2nd set value which is the reception lower limit level,
Small range scanning control means for scanning the antenna in a small range and setting the attitude of the antenna in a direction in which the reception level is high during that; when the reception level is less than a second set value, the antenna is set in a wider range than the small range scanning. Search scan control means for performing a search scan; and a change in the reception level during the scan in the small range, and when the change is less than a third set value which is a threshold value for determining whether there is a change, the first setting An attitude control device for an antenna on a moving body, comprising: a setting value updating means for updating the value to a value slightly smaller than a high value of the reception level during the scanning of the small range.