JPH0829512A - Method and system for controlling tracking of mobile antenna - Google Patents

Abstract

PURPOSE:To realize good follow-up performance of beam direction at the time of turning of a mobile by rotary controlling the beam direction of a mobile antenna in response to the turning state information of a mobile and monitoring the turning state information again after rotary control of the beam direction i.n response to receiving sensitivity information in case of unturned state information of the mobile. CONSTITUTION:When a turning state detection means 7 delivers first turn,ing state information, means 3 rotary controls the beam direction of a mobile antenna 1 through an antenna control section 9 depending on the first turning state information. When the means 7 delivers second turning state information, the means 3 rotary controls the beam direction of the mobile antenna 1 through the antenna control section 9 depending on the receiving sensitivity information of a receiver 6. Upon finishing the rotary control, the turning state information from the means 7 is monitored again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking control method and a tracking control device for a mobile body mounted antenna, and more particularly to a received signal level of a signal received by a mobile body mounted antenna mounted on a mobile body such as a vehicle. And the turning state of the moving body is detected,
The present invention relates to a tracking control method and a tracking control device for a mobile body mounted antenna that controls the beam pointing direction of the mobile body mounted antenna using the detected information.

[0002]

2. Description of the Related Art When performing communication through a satellite or receiving a satellite broadcast, in order to receive a good quality, the beam width of an antenna installed on the ground station side is narrowed,
It is necessary to increase the gain in the predetermined direction. By the way, when such an antenna is mounted on a moving body such as a railroad car or an automobile and the same service is received, the elevation angle or azimuth plane of the antenna may be changed depending on the running state of the moving body or the reception state of satellite radio waves. The beam pointing direction of the antenna must be scanned with and the beam pointing direction must be controlled so as to match the satellite direction.

For example, when the moving body is an automobile,
As described in the following first to third examples, various variations occur in the reception state depending on the state of the road on which the vehicle is traveling, so it is necessary to control the beam pointing direction of the antenna in response to the variation in the reception state. is there. That is, the first is a case where a road is greatly curved, and when traveling on such a road at a relatively high speed, the azimuth angle of the satellite viewed from the vehicle changes greatly within a short time. . In this case, it is necessary to constantly scan and control the beam pointing direction of the antenna at a speed that follows the turning of the automobile, and always match the beam pointing direction of the antenna with the satellite direction. Secondly, the road is inclined like a slope, and when traveling on such an inclined road, the elevation angle of the satellite viewed from the automobile changes. In this case, it is necessary to control the beam pointing direction of the antenna according to the tilted state, and also to match the beam pointing direction of the antenna with the satellite direction. Thirdly, in the case of a road in a tunnel or a road having radio wave obstacles such as buildings around it, when traveling on such a road, the radio waves received from the satellite are blocked or momentarily cut off. In this case, when the shielding or interruption of the received radio wave is eliminated and the received radio wave returns to a state in which it can be received well again, the satellite should be immediately captured without losing the satellite direction so that the received radio wave can be quickly captured. It is necessary to prepare for tracking in the direction.

Generally, the tracking control method used in the antenna mounted on a mobile body determines the satellite direction from the intensity of the radio wave received from the satellite and directs the antenna beam in that direction. It is roughly classified into an open loop control system in which the antenna beam is directed in a predetermined azimuth direction or elevation angle direction based on information from a sensor that detects a running state. Among these, several closed loop control methods are known. For example, the directivity direction of the antenna beam is switched by a certain angle, the reception signal level is detected each time, and the detected reception signal is detected. There is a step track control system in which the signal levels are compared and the antenna beam is directed in the direction in which the received signal level is maximized. This step-track control method can perform the required tracking control only by using a general-purpose receiving means, but the tracking error becomes large when the received signal level is low or when the received signal level fluctuates greatly. I will end up. On the other hand, the open loop control method
This is a control method in which the movement of the moving body is detected by an angle sensor or an angular velocity sensor mounted on the moving body, the antenna beam is scanned so that the turning angle of the antenna due to the turning of the moving body is canceled, and the satellite is tracked. Although this open loop control system can perform tracking control regardless of whether the radio waves received from the satellite are shielded or a momentary interruption occurs, it is a feed-forward type control, so it will inevitably cause a tracking error. The angular velocity sensor is easily affected by disturbances such as changes in ambient temperature, and the sensor output fluctuates due to disturbances.
The tracking error becomes large.

Here, FIG. 5 is a schematic block diagram showing an example of a known tracking control device for an antenna mounted on a moving body, which adopts a tracking method mainly for closed loop control, and is disclosed in Japanese Patent Laid-Open No. 3-175385. It has been disclosed.

Referring to FIG. 5, a mobile body mounted antenna 51 is provided.
Is composed of a plurality of element antennas 52 and constitutes a phased array antenna capable of electrically beam scanning. The mobile-mounted antenna 51 receives a radio wave from a satellite by a plurality of element antennas 52 and outputs it to the next beam pointing direction driving means 53. Beam pointing direction driving means 53
Is a phase shift circuit 54 connected to each element antenna 52 and a synthesis circuit 5 for synthesizing outputs of these phase shift circuits 54.
It consists of 5. The beam pointing direction drive means 53 moves by changing the signal phase received by each element antenna 52 by setting the amount of phase shift of each phase shift circuit 54 by the pointing control signal supplied from the antenna controller 59. The body-mounted antenna 51 is directed so that the beam direction is a predetermined direction. In addition, each phase shift circuit 5
The output of No. 4 is power-combined by the combining circuit 55 and output to the next signal receiving means 56. The signal receiving means 56 is composed of a general-purpose radio receiver, performs processing such as frequency conversion, amplification, demodulation and the like on the received signal and sends the demodulated signal to a signal processing system (not shown). The received signal level is sent to the control unit 59. The angular velocity detecting means 57 includes an angular velocity sensor 58 for detecting a turning state of the moving body, and sends angular velocity information generated when the moving body turns from the angular velocity sensor 58 to the next antenna control unit 59. The antenna control unit 59 generates a pointing control signal based on the received signal level from the signal receiving unit 56 and the angular velocity information from the angular velocity sensor 58, and then performs a signal processing as described below to generate the pointing control signal. Is supplied to the beam pointing direction drive means 53.

FIG. 6 is a flow chart showing a main operation process when the tracking control apparatus shown in FIG. 5 performs antenna tracking control in the azimuth direction by a tracking method mainly including closed loop control.

Therefore, the outline of the antenna tracking control operation based on the known closed loop control system will be described with reference to the flow chart shown in FIG. The following control operations are all executed by the antenna controller 59.

The first three steps S50 to S52 relate to satellite acquisition means, the following two steps S53 to S54 relate to reference level setting means, and the last few steps S55. The steps S62 to S62 relate to the antenna tracking control means.

First, in the satellite search means, step S
In 51, according to the flow chart for performing satellite search shown in FIG. 7 (this flow chart will be described later), the beam directions are sequentially switched so as to direct the antenna beam in all directions, and the received signal level is changed every time the beam is switched. The direction in which the maximum received signal level (Levmax) among the detected received signal levels is detected is determined as the satellite direction.

Next, in step S52, a pointing control signal for pointing the antenna beam in the satellite direction is sent to the beam pointing direction driving means 53, and the satellite capturing means is terminated.

Secondly, the reference level setting means reads the received signal level (Lev1) in the satellite direction in step S53.

Next, in step S54, two standards are used based on the read reception signal level (Lev1), that is, a beam switching standard (SL) and a reception signal which are standards when switching (scanning) the antenna beam. A reception radio wave blocking judgment criterion (TL) which is a judgment criterion when the signal is blocked is set. The beam switching reference (SL) is the level (L
ev1), which is a level slightly smaller than that of ev1), the reception radio wave blocking determination standard (TL) is smaller than the beam switching standard (SL), and has a relationship of Lev1>SL> TL.

Thirdly, the antenna tracking control means reads the current received signal level (Lev2) in the pointing direction of the antenna beam in step S55.

Next, in step S56, it is determined whether or not the received signal level (Lev2) is lower than the beam switching reference (SL). And the level (Lev2)
When it is determined that is smaller than the reference (SL) (Y), the process proceeds to the next step S57, and when it is determined that the level (Lev2) is not smaller than the reference (SL) (N), the level (Lev2) is set. Since it is sufficiently large and it is not necessary to switch the pointing direction of the antenna beam, the process returns to the previous step S55.

Subsequently, in step S57, the reception signal level (Lev2) is the reception radio wave blocking judgment criterion (TL).
Is greater than or equal to. And the level (Le
When it is determined that v2) is larger than the reference (TL) (Y), the process proceeds to the next step S58, and the level (Lev2) is set.
When it is determined that is not larger than the reference (TL) (N), the process proceeds to another step S60.

Next, in step S58, the antenna control means 59 reads the angular velocity information obtained by the angular velocity sensor 58.

Then, in step S59, the read angular velocity information is compared with the turning judgment reference to judge whether or not the moving body is in a turning state. When it is determined that the moving body is in the turning state (Y), the process proceeds to the next step S62, and when it is determined that the moving body is not in the turning state (N), the process proceeds to another step S61.

Further, in step S60, since the received signal level (Lev2) is smaller than the reference (TL), it is determined that the received radio wave has been cut off, and the beam control is performed when the received radio wave is cut off. The beam control at the time of blocking the received radio wave is in accordance with a flow chart as shown in FIG. 8A (this flow chart will be described later), and is mainly based on open loop control. Then, when a series of operation processes in the beam control at the time of blocking the received radio wave is completed, the process returns to the previous step S55.

On the other hand, in step S61, since it is determined that the moving body is not turning, beam control is performed when the moving body goes straight. The beam control when the moving body goes straight is in accordance with a flow chart as shown in FIG. 9A (this flow chart will also be described later), and a step track control method (this control method is used) by using the received signal level. It is one of the closed loop control methods as described above), and controls the beam pointing direction. Then, when a series of operation processes in the beam control when the moving body goes straight ahead is completed, the process returns to the previous step S55.

Further, in step S62, since it is determined that the moving body is turning, beam control is performed when the moving body is turning. The beam control at the time of turning of the moving body is in accordance with a flow chart as shown in FIG. 10A (this flow chart will also be described later), and the step track is performed by using the turning direction of the moving body and the received signal level. The beam pointing direction is controlled by the method. Then, when a series of operation processes in the beam control at the time of turning the moving body is completed, the previous step S55
Return to

When the satellite tracking control is performed according to the flow chart as described above, when the received signal level is lowered due to the turning of the moving body, the antenna beam is scanned in the direction opposite to the turning direction of the moving body, and the step track control is performed. Depending on the method, the antenna beam pointing direction coincides with the direction in which the received signal level is high. Further, even if the received signal level is lowered for some reason while the moving body is moving straight, the direction of the antenna beam is made to coincide with the high received signal level direction by the step track control method. Furthermore, even if the mobile body turns while the received radio wave is blocked, the antenna beam pointing direction matches the satellite direction due to the open loop control. It is possible to capture radio waves received from satellites.

Next, FIG. 11 is a schematic block diagram showing an example of a known tracking control device for an antenna mounted on a moving body using an open loop control method, which is disclosed in IEICE Technical Research Report SANE 90-51. It has been done.

In FIG. 11, the movable body mounting antenna 51, the beam pointing direction driving means 53, and the signal receiving means 5 of this example are shown.
Reference numeral 6 has the same configuration as that of the mobile-body-mounted antenna 51, the beam pointing direction driving means 53, and the signal receiving means 56 shown in FIG. 5, and has the same connection relationship as that shown in FIG. It has a connection relationship.

The angular velocity detecting means 57 'of this example comprises an angular velocity sensor 58' and an integrated signal processing circuit 62. The angular velocity sensor 58 'is different from the angular velocity sensor 58 shown in FIG. It uses an optical fiber gyro with high detection accuracy. In addition to this, the present example uses an azimuth sensor 60 including a geomagnetic sensor 61. The geomagnetic sensor 61 detects the absolute azimuth of a moving body and sends the detected value to the next antenna control unit 59 '. To do. Furthermore, the antenna control unit 59 ′ of this example includes the signal receiving unit 5
Received signal level supplied from 6 and angular velocity detection means 5
Based on the turning angle information supplied from 7'and the absolute azimuth information of the moving body supplied from the azimuth sensor 60, a directional control signal is generated after the signal processing as described below, and this directional control signal is generated. It is supplied to the beam directing direction driving means 53.

Next, FIG. 12 is a flow chart showing a main operation process when the antenna tracking control is performed by the tracking control device shown in FIG.

Using the flowchart shown in FIG. 12,
An outline of the antenna tracking control operation by the known open loop control method will be described. The following control operations are all executed by the antenna controller 59 ′.

The first step S110 is related to the satellite acquisition means, and is followed by several steps S111.
The steps S114 to S114 relate to the antenna tracking control means.

First, in the satellite capturing means, step S1
10, the absolute direction information of the moving body detected by the direction sensor 60 and the known satellite position information (geostationary satellite) are used together to obtain the relative direction of the satellite with respect to the moving body, and the obtained direction and movement. The pointing control signal is sent to the beam pointing direction drive means 53 so that the beam pointing direction of the body-mounted antenna 51 coincides.

Next, in step S111, the tracking control means of the antenna reads the turning angle information obtained by processing the angular velocity information detected by the angular velocity sensor 58 'by the integral signal processing circuit 62.

Subsequently, in step S112, the azimuth angle control of the antenna is performed using the turning angle information. This control is performed by an open loop control method in which the beam pointing direction of the mobile-body mounted antenna 51 is scanned in the direction opposite to the turning direction of the moving body by the amount of the turning angle.

Next, in step S113, the received signal level obtained by the signal receiving means 56 is read and its statistical processing is performed. As a result, if the received signal level is 3 dB lower than the received signal level immediately after the end of capturing in step S110 and the fluctuation range is large, it is determined that the received radio wave is blocked, and the process returns to step S111. On the other hand, when the fluctuation range is small, the process proceeds to the next step S114. However, when the turning angle of the moving body is large, the process returns to step S111 without proceeding to the next step S114.

Then, in step S114, the pointing direction of the antenna beam is corrected using the received signal level. This modification scans the antenna beam pointing direction in the azimuth direction by switching angle (1 °) by the step track control method, reads the received signal level each time the scanning is performed,
The antenna beam pointing direction is made to coincide with the direction in which the received signal level is maximized. Then, after the azimuth is corrected, the process returns to step S111.

If tracking control of the satellite is performed according to such a flow chart, the tracking control by the open loop control system is executed regardless of the shielding of the received radio wave and the instantaneous interruption, and the turning obtained by the angular velocity detecting means 57 '. The beam pointing direction of the mobile body mounted antenna 51 is scanned so as to cancel the angle. For example, when the moving body turns, the beam pointing direction is corrected by the turning angle in the direction opposite to the turning of the moving body with reference to the turning angle obtained by the angular velocity detecting means 57 '. Further, even if the beam pointing direction of the mobile body mounted antenna 51 is deviated due to the accumulated error of the angle generated in the integrated signal processing circuit 62, and the received signal level is lowered, the step track control system of step S114 is started and the beam pointing direction is changed. To the direction in which the received signal level is higher. However, when the received signal level decreases and the level fluctuation is large, it is determined that the received radio wave is blocked, and the process does not proceed to step S114.
That is, the tracking by the step track control method is not performed, and the tracking error does not occur.

Here, the satellite search control S51 executed by the flowchart shown in FIG. 6, the beam control S60 when the received radio wave is blocked, the beam control S61 when the moving body goes straight,
The beam control S62 during turning of the moving body will be sequentially described. Note that all of these controls are executed by the antenna controller 59.

First, the satellite search control S51 shown in FIG. 7 is executed according to the flowchart described below.

First, in step S70, the maximum value (Levmax) of the received signal level is initialized to zero (Levmax = 0).

Then, in step S71, a pointing control signal is sent to the beam pointing direction driving means 53 to slightly switch the beam pointing direction of the movable body mounting antenna 51.

Next, in step S72, the received signal level (Lev0) is read.

Subsequently, in step S73, it is determined whether or not the read reception signal level (Lev0) is larger than the maximum reception signal level (Levmax).
Then, the level (Lev0) is the maximum value (Levmax)
When it is determined that the level is larger than the value (Y), the process proceeds to step S75, and the level (Lev0) is the maximum value (Levmax).
When it is determined that the value is not larger than (N), the process proceeds to another step S74.

Next, in step S74, the obtained level (Lev0) is set to the maximum value (Lev0) of the received signal level.
(max) and simultaneously store the beam pointing direction at that time.

Finally, in step S75, it is determined whether or not the beam pointing directions of the mobile body mounting antenna 51 have been switched to all directions. When it is determined that the omnidirectional switching has been performed (Y), the series of satellite search operations is terminated, while when it is determined that the omnidirectional switching has not been performed yet (N), the process returns to the previous step S71. .

Secondly, the beam control S60 at the time of blocking the received radio wave shown in FIG. 8A is executed according to the flow chart described below.

First, in step S76, the built-in timer is set to zero and started, and the process proceeds to the open loop control described below.

In the open loop control, first, in step S77, the angular velocity information obtained by the angular velocity sensor 58 is read.

Next, in step S78, the read angular velocity information is integrated over time to obtain the turning angle of the moving body.

Subsequently, in step S79, it is determined whether or not the obtained turning angle is larger than the switching angle (Δθ) in the beam pointing direction. When it is determined that the turning angle is larger than the switching angle (Δθ) (Y), the next step S80.
On the other hand, when it is determined that the turning angle is not larger than the switching angle (Δθ) (N), the process proceeds to another step S81.

Next, in step S80, the beam pointing direction of the antenna 51 mounted on the moving body is rotated by a switching angle (Δθ) of the beam pointing direction in the direction opposite to the turning direction of the moving body. In this case, as shown in FIG. 8B, for example, from the state in which the beam pointing direction matches the satellite direction, the moving body moves to the left twice the switching angle (Δθ) twice (2Δθ).
If the beam turns only, the beam pointing direction is switched to the right two times with the switching angle (Δθ).

Next, in step S81, after the beam pointing direction is switched, the received signal level (Lev3) is read.

In the next step S82, the read reception signal level (Lev3) is the beam switching reference (Sev).
It is determined whether it is smaller than L). When it is determined that the level (Lev3) is smaller than the reference (SL) (Y), the process proceeds to the next step S83, while it is determined that the level (Lev3) is not smaller than the reference (SL) (N). If so, the antenna beam control at the time of blocking the received radio wave is terminated.

Succeedingly, in a step S83, it is determined whether or not the timer started in the step S76 exceeds a time limit. When it is determined that the timer has exceeded the time limit (Y), the next step S8
4, and on the other hand, when it is determined that the timer has not exceeded the time limit (N), the process returns to step S77.

Next, in step S84, the flow chart of the satellite search control shown in FIG. 7 is executed.

Next, in step S85, the maximum value (Levm) of the received signal level obtained by the satellite search is obtained.
It is determined whether ax) is larger than the beam switching reference (SL). Then, the maximum value (Levmax) is the reference (S
If it is determined that the value is larger than (L) (Y), the process proceeds to the next step S86, and the maximum value (Levmax) is the reference (S).
When it is determined that it is not larger than L) (N), the process returns to the previous step S84.

Finally, in step S86, a pointing control signal for causing the beam pointing direction of the mobile-mounted antenna 51 to coincide with the satellite direction is generated, and the series of operations in the antenna beam control when the reception radio wave is cut off is completed.

Thirdly, the beam control S61 shown in FIG. 9A when the moving body goes straight is executed according to the flow chart described below.

First, in step S87, as shown in FIG. 9B, the beam directing direction of the movable body mounting antenna 51 is changed from the original position A to the position B to the left of the original position A at the switching angle (Δθ). Switch to.

Next, in step S88, the received signal level (Le
Read v5).

Succeedingly, in a step S89, it is determined whether or not the reception signal level (Lev2) obtained in the flowchart shown in FIG. 6 is higher than the reception signal level (Lev5). And the level (Lev2)
Is greater than the level (Lev5) (Y), the process proceeds to the next step S90, while the level (Lev5) is
When it is determined that v2) is not larger than the level (Lev5) (N), the beam control when the moving body goes straight is ended.

In the next step S90, the beam pointing direction of the mobile-mounted antenna 51 is changed to a switching angle (2Δθ) that is twice the switching angle (Δθ), as shown in FIG. 9B.
Is switched from the original position A to the position C in the right adjacent direction.

Next, in step S91, the received signal level (Le
Read v6).

Succeedingly, in a step S92, it is determined whether or not the reception signal level (Lev2) is higher than the reception signal level (Lev6). And the level (Lev
When it is determined that 2) is greater than the level (Lev6) (Y), the process proceeds to the next step S93, while when it is determined that the level (Lev2) is not greater than the level (Lev6) (N), this The beam control when the moving body goes straight is ended.

Finally, in step S93, the beam directing direction of the mobile body mounting antenna 51 is changed to the switching angle (Δθ).
Then, it is returned to the position (original position) A in the direction on the left side again, and the beam control when the moving body goes straight is completed.

By carrying out such control, it is possible to direct the beam in the direction in which the received signal level is high by sequentially switching the beam directing directions of the mobile-mounted antenna 51 to the two adjacent directions.

Fourthly, the beam control S62 at the time of turning of the moving body shown in FIG. 10A is executed according to the flow chart described below.

First, in step S94, the angular velocity information obtained by the angular velocity sensor 58 is read, and the turning direction of the moving body is obtained using the read angular velocity information. At this time, if the obtained turning direction is right, the process proceeds to step S95, and if the obtained turning direction is left, the process proceeds to step S99.

Next, in step S95, the beam pointing direction of the mobile-unit mounted antenna 51 is switched to the left adjacent direction opposite to the turning direction of the mobile unit.

Next, in step S96, the received signal level (Lev4) when the beam pointing direction is switched is read.

Then, in step S97, it is determined whether or not the received signal level (Lev2) obtained in the flowchart shown in FIG. 6 is higher than the received signal level (Lev4). When it is determined that the level (Lev2) is larger than the level (Lev4) (Y), the process proceeds to the next step S98, while the level (Lev2) is
When it is determined that (2) is not larger than the level (Lev4) (N), the beam control at the time of turning the moving body is terminated without returning the beam pointing direction of the moving body mounted antenna 51 to the original position.

Subsequently, in step S98, the beam directing direction of the antenna 51 mounted on the moving body is switched to the right adjacent direction to return to the original position as shown in FIG. End the beam control of.

On the other hand, in step S99, the beam pointing direction of the vehicle-mounted antenna 51 is switched to the right adjacent direction opposite to the turning direction of the vehicle.

Next, in step S100, the received signal level (Lev4) when the beam pointing direction is switched
Read.

Then, in step S101, it is determined whether or not the received signal level (Lev2) obtained in the flowchart shown in FIG. 6 is higher than the received signal level (Lev4). And the level (Lev2)
Is determined to be greater than the level (Lev4) (Y), the process proceeds to the next step S102, while the level (L
ev2) is not greater than the level (Lev4) (N)
If it is determined that the beam control direction at the time of turning of the moving body is ended without returning the beam pointing direction of the moving body mounted antenna 51 to the original position.

Subsequently, in step S102, the beam pointing direction of the moving body mounted antenna 51 is switched to the left adjacent direction to return to the original position, and the beam control when the moving body goes straight is completed.

By performing such control, it is possible to direct the beam in the direction in which the received signal level is high, while switching the beam directing direction of the mobile unit-mounted antenna 51 to the direction opposite to the turning direction of the mobile unit.

[0075]

By the way, in the known tracking method mainly based on closed loop control, when the antenna beam control is performed according to the flowchart shown in FIG. Since the turning state of the moving body is determined, a time delay occurs until the beam pointing direction of the moving body mounted antenna 51 is controlled by turning the moving body. When the moving body continuously turns at a high angular velocity, a pointing error occurs due to a time delay in tracking the moving body with respect to the turning. As described above, the known closed loop control system has a problem that the followability of the beam pointing direction to the turning of the moving body is not good.

On the other hand, in the known tracking method based on open loop control, when the tracking control in the beam pointing direction is performed according to the flowchart shown in FIG. 12, the moving body is in a stopped or non-turning state. However, since open-loop control is always performed using the output of the angle sensor, if the stationary output of the angle sensor contains a drift component, there is a problem that a tracking error corresponding to the drift component occurs. In addition, there is a problem that the tracking error must be corrected by executing the control by the correction loop as the received signal level decreases.

The present invention eliminates such a problem, and an object thereof is to improve the followability of the beam pointing direction with respect to the turning of the mobile unit and to minimize the occurrence of tracking error. To provide a tracking control method and a tracking control device.

[0078]

In order to achieve the above object, the present invention detects a turning state of a moving body and outputs turning state information, and outputs from the turning state detecting means. Monitoring means for constantly monitoring the turning state information, and beam directing direction driving means for controlling the tracking state of the mobile-mounted antenna, and the turning state detecting means generates first turning state information indicating the turning state. When I did
The beam pointing direction drive means controls the rotation of the beam pointing direction of the mobile-mounted antenna in accordance with the first turning state information, and the turning state detecting means generates second turning state information indicating a non-turning state. At this time, there is provided first means for controlling the rotation of the beam pointing direction of the moving body mounted antenna by the beam pointing direction driving means according to the receiving sensitivity information.

In order to achieve the above-mentioned object, the present invention provides a movable body-mounted antenna capable of controlling a beam directing direction, beam directing direction driving means for setting a beam directing direction of the movable body mounted antenna, and Signal receiving means for generating a reception signal level coupled to a mobile body mounted antenna, swing state detecting means for detecting a swing state of the mobile body and generating swing state information, and the received signal level and the swing state information. And a control means for controlling the beam pointing direction driving means in response to the beam pointing direction driving means, and the control means further comprises preset beam switching criteria and reception radio wave interruption determination criteria,
Storage means for respectively storing the received signal level, a preset turning judgment standard, and the turning state information, comparison of the received signal level and the beam switching standard, and the received signal level and the received radio wave interruption judgment standard Comparison means for performing comparison and comparison between the turning state information and the turning determination reference, timing means for starting or ending timing according to the comparison result of the comparison means, and directing for supplying to the beam pointing direction driving means A second control means is provided which has a directivity control signal generation means for generating a control signal and a centralized control means for centrally controlling each component in the control means.

[0080]

In the first means, when the turning state detecting means generates the first turning state information indicating that the moving body is in the turning state, the pointing control in response to the first turning state information. A signal is supplied to the beam pointing direction driving means, and the beam pointing direction of the mobile-mounted antenna is thereby controlled to rotate. On the other hand, when the turning state detecting means generates the second turning state information indicating that the moving body is in the non-turning state, the pointing control signal according to the reception sensitivity information is supplied to the beam pointing direction driving means, Thus, after the beam-directed direction of the movable body mounted antenna is controlled to be rotated, the turning state information from the turning state detecting means is monitored again.

As described above, according to the first means, the turning state of the moving body is first discriminated between the turning state and the non-turning state, and immediately when the moving body is decided to be in the turning state. The control of the beam pointing direction at the time of turning the moving body is performed.

Further, in the second means, when the turning state information is generated from the turning state detecting means, the comparing means compares the turning state information with the turning judgment reference read from the storing means. Based on the comparison result, it is determined whether the moving body is in the turning state or in the non-turning state (stationary state), and further, the cutoff time of the received signal radio wave is measured by the time measuring means, and the cutoff time is determined. Open-loop control or closed-loop control is performed according to the length of.

[0083]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a tracking control device for a mobile body mounted antenna according to the present invention, and shows an example in which an automobile is used as a mobile body.

In FIG. 1, reference numeral 1 denotes a mobile body mounted antenna,
2 is an element antenna, 3 is a beam pointing direction driving means, 4 is a phase shift circuit, 5 is a combining circuit, 6 is a signal receiving means, 7 is a turning state detecting means, 8 is an angular velocity sensor, 9 is also control means and monitoring means. The antenna controller 10 is also a storage means,
Reference numeral 11 is a comparing means, 12 is a time measuring means, 13 is an orientation control signal generating means, and 14 is a general control means.

The movable body mounting antenna 1 is composed of a plurality of element antennas 2 and constitutes a phased array antenna capable of electrically beam scanning. Mobile body mounted antenna 1
Receives a radio wave received from a satellite by a plurality of element antennas 2 and receives a received signal from the beam directing direction driving means 3 in the next step.
Supply to. The beam pointing direction driving means 3 is composed of a phase shift circuit 4 connected to each element antenna 2 and a synthesis circuit 5 that power-synthesizes the output signals of these phase shift circuits 4.
The beam pointing direction driving means 3 sets the amount of phase shift of each phase shift circuit 4 by the pointing control signal supplied from the pointing signal generating means 11 built in the antenna control unit 9, and transmits the respective element antennas 2. Change the signal phase,
The beam pointing direction of the mobile-mounted antenna 1 is changed to a predetermined direction. The signal receiving means 6 is composed of a general-purpose radio receiver, performs known signal processing such as frequency conversion, amplification and demodulation on the received signal, and sends the demodulated signal to a signal processing system (not shown). The received signal level is sent to the antenna control unit 9 of. The turning state detecting means 7 includes an angular velocity sensor 8 for detecting the turning state of the automobile, and sends the angular velocity information obtained by the angular velocity sensor 8 to the next antenna control unit 9. The antenna control unit 9 includes a storage unit 10, a comparison unit 11, a timing unit 12, a pointing control signal generation unit 13, and an integrated control unit 14. Then, the storage unit 10 stores the preset beam switching standard (SL), reception radio wave blocking judgment standard (TL), turning judgment standard, reception signal level, and angular velocity information, respectively. The comparing means 11 compares the received signal level with the beam switching reference (SL), compares the received signal level with the received radio wave blocking determination reference (TL), and compares the angular velocity information with the turning determination reference. The clocking means 12 starts or ends clocking according to the comparison result of the comparing means 11. The pointing control signal generating means 13 generates a pointing control signal and supplies it to the beam pointing direction driving means 3. The integrated control means 14
The storage unit 10, the comparison unit 11, the time counting unit 12, and the directivity control signal generation unit 13 are collectively controlled.

FIG. 2 is a flow chart showing a main operation process when the antenna tracking control is performed in the first embodiment shown in FIG.

The operation of the first embodiment will be described with reference to the flow chart shown in FIG. In this description, tracking control is performed only in the azimuth plane. Further, all of the antenna tracking control is executed by one or more constituent means 10 to 13 incorporated in the antenna control means 9.

First, in step S1, satellite search is performed. This satellite search is performed according to the flow chart shown in FIG. 7 which has already been described. While switching the beam pointing directions in all directions, the received signal level (Lev0) is detected each time the switching is performed, and the level (Lev0) is detected.
0) The pointing control signal is transmitted so that the beam pointing direction coincides with the direction showing the maximum value (Levmax).

Next, in step S2, the beam pointing direction of the vehicle-mounted antenna 1 is set to the satellite direction confirmed by the satellite search.

Next, in step S3, the received signal level (Lev1) in the satellite direction is read.

In the next step S4, the beam switching reference (SL) is determined based on the read level (Lev1).
And the received radio wave blocking judgment criterion (TL). These two
The two standards (SL) and (TL) are the mobile-mounted antenna 1
The reference when switching (scanning) the beam pointing direction of
As a reference for determining that the received radio wave has been blocked, as shown in FIG. 2, the reference (SL) is slightly smaller than the maximum value (Levmax) of the received signal level, and the reference (TL) is It is smaller than the standard (SL).

Subsequently, in step S5, the time measuring means (timer) 12 for measuring the waiting time for starting the recapture is turned off.

Next, in step S6, the angular velocity information value (angular velocity) As obtained by the angular velocity sensor 8 is read.

Next, at step S7, the difference between the angular velocity information value As and the stationary angular velocity information value As ₀ obtained by the angular velocity sensor 8 when the vehicle is stationary (non-turning) (| As
-As ₀ |) is smaller than the turning determination criterion (ΔAs). When it is determined that the difference (| As-As ₀ |) is smaller than the reference (ΔAs) (Y), it is determined that the vehicle is in a straight traveling state, and the next step S8 is performed.
While the difference (| As-As ₀ |) is the reference (ΔA
When it is determined that the value is not smaller than (s) (N), it is determined that the vehicle is in a turning state, and the process proceeds to another step S13. The reference (ΔAs) is determined so as to have a value larger than the fluctuation width due to the response error and drift of the angular velocity sensor 8.

In the next step S8, the received signal level (Lev2) is read.

Subsequently, in step S9, it is determined whether or not the read level (Lev2) is smaller than the beam switching reference (SL). And the level (Lev2)
Is smaller than the reference (SL) (Y), the process proceeds to the next step S10, while the level (Lev2) is set.
When it is determined that is not smaller than the reference (SL) (N), the process proceeds to another step S14.

Next, in step S10, it is determined whether or not the level (Lev2) is smaller than the reception radio wave blocking determination criterion (TL). When it is determined that the level (Lev2) is smaller than the reference (TL) (Y), the process proceeds to the next step S11, while it is determined that the level (Lev2) is not smaller than the reference (TL) (N). If so, the process proceeds to another step S15.

In the next step S11, it is determined whether or not the timer (clocking means) 12 is turned on.
When it is determined that the timer 12 is turned on (Y), the process proceeds to the next step S12, while the timer 12
When it is determined that is not turned on (N), the process proceeds to another step S17.

Next, in step S12, it is determined whether or not the timer 12 has timed the time limit. When the timer 12 determines that the time limit has been timed (Y), the process returns to the first step S1, while when the timer 12 determines that the time limit has not been timed (N), the process proceeds to another step S16. .

Since it is determined in step S13 that the vehicle is in a turning state,
The second beam control at the time of turning of the moving body is performed according to the flowchart as shown in FIG. The second beam control at the time of turning the moving body is a control centered on the open loop control, and a flowchart for this control will be described later.

Furthermore, in step S14, since the level (Lev2) is larger than the reference (SL), the signal reception state is good. Therefore, the beam pointing direction is not switched, the timer 12 is turned off, and the process returns to the previous step S6.

Next, in step S15, since the level (Lev2) is larger than the reference (TL) and smaller than the reference (SL) (TL≤Lev2 <SL), the signal is received due to the deviation of the beam pointing direction. It is determined that the state is slightly deteriorated, and the process proceeds to the next step S16.

In the next step S16, beam control is performed when the moving body goes straight. This control is performed according to the flow chart shown in FIG. 9A, which has already been described. The step track method is used to match the beam pointing direction with the direction in which the received signal level increases. In this case as well, after the beam control for moving the vehicle straight is performed, the timer 12 is turned off and the process returns to the previous step S6.

Next, in step S17, the timer 12, which is off, is turned on.

Finally, in step S18, the time measured by the timer 12 is initialized to 0. Then, after the initialization is completed, the process returns to the previous step S6.

Next, a flow chart for executing the second beam control S13 at the time of turning of the moving body shown in FIG. 3 will be described. It should be noted that all of this control is also executed by the respective constituent means 10 to 14 incorporated in the antenna control means 9.

First, in step S20, the difference (| A
The turning angle (α) of the automobile is obtained by time integration of s-As ₀ |.

Next, in step S21, it is determined whether or not the obtained turning angle (α) is larger than the beam switching angle (Δθ). When it is determined that the turning angle (α) is larger than the beam switching angle (Δθ) (Y), the process proceeds to the next step S22, while the turning angle (α) is larger than the beam switching angle (Δθ). If it is determined that there is no (N), the process proceeds to another step S23.

Subsequently, in step S22, the beam pointing direction of the antenna 1 mounted on the moving body is switched to the adjacent beam pointing direction opposite to the turning direction of the automobile.

Next, in step S23, it is determined whether or not the timer (clocking means) 12 is on. Then, when it is determined that the timer 12 is on (Y), the process proceeds to the next step S24, while when it is determined that the timer 12 is not on (N), the second beam control during the turning of the moving body is performed. Is ended, and the process proceeds to step S6 in the antenna tracking control shown in FIG.

Finally, in step S24, it is determined whether the timer 12 has reached the time limit. When it is determined that the timer 12 has reached the time limit (Y), the process proceeds to the first step S1 in the flowchart of the antenna tracking control shown in FIG.
When it is determined that the timer 12 has not reached the time limit (N), the second beam control at the time of turning of the moving body is ended, and the process proceeds to step S6 in the antenna tracking control shown in FIG.

If the antenna tracking control is performed according to the flow charts shown in FIGS. 2 and 3, when the vehicle turns at a large angular velocity, the angular velocity sensor 8 is used regardless of the blocking of the received radio wave and the occurrence of the instantaneous interruption. Antenna tracking control is performed by open loop control using the obtained angular velocity information, and the beam pointing direction of the mobile body mounted antenna 1 is scanned so as to cancel the turning angle of the antenna caused by turning of the automobile. In addition, when the vehicle travels on a gently curved road or a straight road, if the reception radio wave is not blocked, the antenna tracking control by the step track control is performed, and the beam pointing direction increases in the direction in which the received signal level increases. Is set. On the other hand, when the received radio wave is cut off, the antenna tracking control by the step track control is not executed, but if the cut-off time of the received radio wave is extremely short like a momentary interruption, the satellite direction is still the beam of the antenna 1 mounted on the mobile unit. Since it is within the width, the antenna tracking control by the step track control is performed after the reception signal level is recovered, and the beam pointing direction is set in the direction in which the reception signal level becomes higher.

In the antenna tracking control according to the flowcharts shown in FIGS. 2 and 3, since the turning state of the automobile is determined using the turning determination reference (ΔAs), the angular velocity sensor 8 The angular velocity output fluctuates due to temperature drift or the like, and even if an automobile that is traveling straight ahead actually appears to turn gently, the antenna tracking control by the open loop control is not performed, and the angular velocity sensor 8 A tracking error based on the fluctuation of the angular velocity output does not occur.

Further, if the antenna tracking control according to the flowcharts shown in FIGS. 2 and 3 is performed,
Even if the received signal level is lowered due to the tracking error based on the open loop control and the tracking becomes impossible, the timer 12 operates to automatically reacquire the satellite after a predetermined time has elapsed, and the antenna is re-acquired. Tracking control can be restarted.

In the above embodiment, the angular velocity sensor 8 is set so as to detect the angular velocity when the vehicle turns, and the antenna tracking control is performed within the azimuth plane of the mobile body mounted antenna 1. If two other angular velocity sensors are provided so as to detect rolling and pitching of an automobile, and the antenna tracking control of the above embodiment is performed based on the outputs of the angular velocity sensors,
The antenna tracking control can be performed within the elevation plane of the mobile-mounted antenna 1.

Further, in the above embodiment, the signal level of the carrier is used as the received signal level, but (C / N) of the received signal and (S of the demodulated signal are used.
/ N) or the like whose value changes according to the reception environment, it can be used for detection of the reception signal level like the carrier.

Next, FIG. 4 is a block diagram showing a second embodiment of a tracking control device for a mobile body mounted antenna according to the present invention, in which an automobile is used as a mobile body as in the first embodiment. explain.

In FIG. 4, 15 is an azimuth detecting means, and 16
Is an azimuth sensor, and other components that are the same as those shown in FIG. 1 are denoted by the same reference numerals.

The difference in the configuration between the second embodiment and the first embodiment is that the azimuth sensor 16 of the second embodiment is different.
In contrast to having the azimuth detecting means 15 consisting of
The third embodiment is only that the azimuth detecting means 15 is not provided, and other than that, there is no structural difference between the first embodiment and the second embodiment.

In the operation of the second embodiment, the angular velocity information obtained by the angular velocity sensor 8 and the azimuth information obtained by the azimuth sensor 16 are used in order to detect the turning state and the complete azimuth of the automobile. However, the essential operation of the antenna tracking control is the same as the operation of the antenna tracking control in the first embodiment already described. Therefore, the description of the operation of the antenna tracking control in the second embodiment will be omitted.

Also, the effect obtained by the second embodiment is almost the same as the effect obtained by the first embodiment already described, and therefore the description thereof is also omitted.

In the above-described embodiments, the moving body mounted antenna 1 has been described as a phased array antenna capable of electrically changing the beam pointing direction, but the moving body mounted antenna 1 applicable to the present invention is described. Is
The present invention is not limited to the phased array antenna, but can be similarly applied to a mobile-body-mounted antenna capable of scanning the beam pointing direction by mechanically rotating the elevation angle or azimuth angle of the antenna.

[0124]

As described above, according to the present invention,
When performing the antenna tracking control, first, the turning state of the moving body is determined, and it is roughly divided into a turning state and a non-turning state.When it is determined that the moving body is in the turning state, the moving body turns immediately. Since the antenna tracking control is started at the time, the time delay until the start of the antenna tracking control is reduced, and as a result, the responsiveness and tracking of the antenna tracking control when the moving body turns at high speed are improved. In comparison with the known antenna tracking control of this kind, there is an effect that it can be made extremely good.

Further, according to the present invention, when the turning state of the moving body is judged, the turning judgment reference is provided in consideration of the accuracy and drift of the angle sensor mounted on the moving body. Regardless of accuracy or drift, the moving body is always in a turning state and a non-turning state (stationary state)
It is possible to effectively discriminate between and, and it is possible to prevent occurrence of a detection error due to drift or the like. Further, even if the received radio wave is blocked, there is an effect that the antenna tracking control for immediately returning to the receiving state is performed after the blocking state is resolved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a tracking control device for an antenna mounted on a moving body according to the present invention.

FIG. 2 is a flowchart showing a main operation process when antenna tracking control is performed in the first embodiment shown in FIG.

FIG. 3 is a flowchart showing an operation process of the present invention when performing the second beam control when the moving body turns.

FIG. 4 is a configuration diagram showing a second embodiment of a tracking control device for a mobile body mounted antenna according to the present invention.

FIG. 5 is a schematic configuration diagram showing an example of a known tracking control device for an antenna mounted on a moving body, which adopts a system mainly based on closed loop control.

FIG. 6 is a flowchart showing a main operation process when performing antenna tracking control based on the system shown in FIG. 5, which mainly includes closed loop control.

FIG. 7 is a flowchart showing a known operation process when performing satellite search.

FIG. 8 is a flowchart showing a known operation process when performing beam control when blocking a received radio wave.

FIG. 9 is a flowchart showing a known operation process when performing beam control when a moving body goes straight.

FIG. 10 is a flowchart showing a known operation process when performing beam control during turning of a moving body.

FIG. 11 is a schematic configuration diagram showing an example of a known tracking control device for an antenna mounted on a moving body, which adopts a system mainly based on open loop control.

FIG. 12 is a flowchart showing a main operation process when performing antenna tracking control based on the method shown in FIG. 11, which is mainly based on open loop control.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 mobile body mounted antenna 2 element antenna 3 beam pointing direction driving means 4 phase shift circuit 5 combining circuit 6 signal receiving means 7 turning state detecting means 8 angular velocity sensor 9 antenna control unit (controlling means and monitoring means) 10 storage means 11 Comparing means 12 Timer (time measuring means) 13 Directional control signal generating means 14 General control means 15 Direction detecting means 16 Direction sensor

Claims (4)

[Claims] 1. A turning state detecting means for detecting a turning state of a moving body and generating turning state information, a monitoring means for constantly monitoring the turning state information output from the turning state detecting means, and a moving body mounted device. Beam pointing direction drive means for controlling a tracking state of the antenna, and when the turning state detecting means generates first turning state information indicating a turning state,
The beam pointing direction drive means controls the rotation of the beam pointing direction of the mobile-mounted antenna in accordance with the first turning state information, and the turning state detecting means generates second turning state information indicating a non-turning state. At this time, a tracking control method for a mobile body mounting antenna, wherein the beam directing direction drive means controls the rotation of the beam directing direction of the mobile body mounting antenna according to the reception sensitivity information. 2. A moving body mounted antenna capable of controlling a beam pointing direction, a beam pointing direction driving means for setting a beam pointing direction of the moving body mounted antenna, and a receiving signal level coupled to the moving body mounted antenna. A signal receiving unit that generates the signal, a turning state detecting unit that detects a turning state of the moving body and generates turning state information, and controls the beam pointing direction driving unit in response to the received signal level and the turning state information. Further comprising a control means, the control means, a storage means for respectively storing preset beam switching reference and reception radio wave interruption determination reference, the received signal level, preset turning determination reference, the turning state information,
Comparing means for comparing the reception signal level with the beam switching reference, comparing the reception signal level with the reception radio wave interruption determination reference, and comparing the turning state information with the turning determination reference, and the comparison means. The clocking means for starting or ending the clocking according to the comparison result, the pointing control signal generating means for generating the pointing control signal to be supplied to the beam pointing direction driving means, and the overall control for controlling the respective constituent means in the control means. A tracking control device for an antenna mounted on a mobile body, which has a built-in control means. 3. The beam pointing direction drive means controls rotation of the beam pointing direction of the moving body mounted antenna, and during the rotation control, the signal receiving means detects a received signal level received by the moving body mounted antenna, The maximum value of the received signal level and the beam pointing direction at that time are stored in the received signal level storage means and the beam pointing direction storage means, respectively, and the beam pointing direction storage means stores the beam pointing direction in the beam pointing direction storage means. A first step of driving and controlling the beam pointing direction of the mobile-mounted antenna; and a second step of detecting a turning angular velocity and a turning direction of the moving body by a turning state detecting means, and monitoring the turning angular velocity and a turning direction by a monitoring means. Step, and when the turning angular velocity and turning direction are detected by the monitoring means, the beam pointing direction driving means A third step of controlling the beam directing direction of the antenna mounted on the moving body with respect to the moving body in a direction opposite to the turning direction and at an angle according to the turning angular velocity, and then returning to the second step; When the turning angular velocity is not detected by the means, the signal receiving means detects the first received signal level of the signal received by the mobile-mounted antenna, and the comparing means detects the first received signal level and the beam switching reference. And a fourth step of outputting a first comparison result, and when the first reception signal level is higher than the beam switching reference according to the first comparison result, the procedure returns to the second step. 5 steps, and if the first reception signal level is smaller than the beam switching reference based on the first comparison result, then the first reception is performed by the comparison means. A sixth step of comparing the signal level with the reception radio wave interruption determination standard and outputting a second comparison result, and the first reception signal level is higher than the reception radio wave interruption determination criterion according to the second comparison result. In this case, the beam pointing direction of the mobile-mounted antenna is moved to either direction, and the signal receiving means detects the second received signal level of the signal received by the mobile-mounted antenna, and the comparison means is used. The second received signal level and the first received signal level are compared with each other, and the beam pointing direction of the mobile-mounted antenna is driven and controlled to a direction with a larger received signal level according to the result of the comparison. Second
The tracking control method of a mobile body mounted antenna, wherein tracking control in the antenna beam pointing direction is performed through each of the seventh step returning to the step. 4. When the first received signal level is smaller than the received radio wave cutoff judgment criterion as a result of the second comparison, the timekeeping means measures the time, and the timekeeping result is still within a predetermined time. When returning to the second step,
On the other hand, tracking control of the antenna beam pointing direction is performed through each of an eighth step of returning to the first step when the time measurement result exceeds a predetermined time, and the eighth step is performed. Tracking control method for mobile antennas.