JPH11153668A - Radar system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar system of which attachment to a moving body is very easy. SOLUTION: Antennas 48, 50 and 52 are fixed to a stage 70 loaded on a self car, emit a radio wave to the front of the self car and receive a reflection wave from the front car. The antenna 50 emits the radio wave to the front and the antennas 48 and 52 emit the radio wave to inclined front to the left and the right. An operation means 8 detects the azimuth of the front car from the reference of the antenna front direction based on the reception signal intensity from each antenna. Also the operation means 8 calculates running speed from the frequency change of the reflection wave from the ground and obtains the running direction using the difference of the running speed calculated with the reception signal of the antennas 48 and 52. The stage 70 is controlled so as to adjust the antenna front direction to the running direction. As the result, the azimuth of the front car detected with the reference of the antenna front direction always becomes that referred by the running direction of the self car even with low fixing accuracy of the antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar system which is mounted on a moving body such as an automobile and detects the azimuth of another moving body running ahead of the moving body.

[0002]

2. Description of the Related Art In recent years, radar devices, especially millimeter wave radar devices, have been used to detect other vehicles, obstacles, traveling lanes, etc., traveling ahead from the viewpoint of ensuring the safety of vehicles, preventing collisions, or automatically driving. Technology is being actively researched and developed. For such applications, a millimeter-wave radar device mounted on an automobile must be able to identify a lane 100 m away, and therefore use a highly directional antenna having a narrow beam width of radiated radio waves. Japanese Patent Application Laid-Open No. 6-24 discloses an example of an apparatus for detecting the direction of a preceding vehicle traveling in front of a host vehicle (automobile equipped with a radar device) using such an antenna.
2230.

[0003]

However, in order to accurately detect the azimuth of the vehicle ahead using an antenna having high directivity, the antenna must be attached to the vehicle with high accuracy. For an antenna about 3 degrees,
The mounting error in the azimuth direction must be less than 1 degree. Therefore, in the past, great care had to be taken when attaching an antenna to a car, and the attaching work was a time-consuming and labor-intensive work. The present invention has been made to solve such a problem, and an object of the present invention is to provide a radar system which is extremely easy to mount on a moving body.

[0004]

In order to achieve the above object, the present invention provides a radar means for detecting the direction of a target in front of a moving object based on the front direction of an antenna, and the radar based on the antenna front direction. Traveling direction detecting means for detecting a traveling direction of a moving body; a head mounted on the moving body, supporting the antenna, and swinging the antenna in a substantially horizontal plane based on a control signal; Head control means for outputting the control signal based on the traveling direction of the moving body detected by the means, and controlling the head so that the front direction of the antenna coincides with the traveling direction of the moving body. The antenna radiates radio waves in at least first and second directions having different directions with respect to the front direction of the antenna to receive a reflected wave, and the traveling direction detecting means includes: And frequency of the received signal from antenna, the antenna and the speed calculating means for calculating a traveling speed of the movable body based on the difference between the frequency of the radio wave radiated,
A first traveling speed calculated by the speed calculation means based on a reception signal from the antenna when the antenna radiates a radio wave in the first direction; and the antenna radiates a radio wave in the second direction. And a traveling direction calculating means for calculating a traveling direction of the moving body in accordance with the second traveling speed calculated by the speed computing means based on the reception signal from the antenna at the time of the operation.

[0005] In the radar system of the present invention, the radar means mounted on the moving body detects the azimuth of the target in front of the moving body with reference to the front direction of the antenna. The direction is detected based on the front direction of the antenna. Then, the pan head control means outputs a control signal based on the traveling direction of the moving body detected by the traveling direction detecting means, and controls the pan head so that the front direction of the antenna coincides with the traveling direction of the moving body. Here, in a state where there is no target such as another moving body ahead, the radar means radiates radio waves from the antenna in at least first and second directions having different directions and receives the radio waves reflected on the ground. As a result, the speed calculating means of the traveling direction detecting means moves based on the difference between the frequency of the received signal and the frequency of the radio wave radiated by the antenna because the frequency of the received signal changes due to the Doppler effect. The running speed of the body can be calculated. The traveling direction calculating means of the traveling direction detecting means includes: a first traveling speed calculated by the speed computing means based on a reception signal from the antenna when the antenna radiates radio waves in the first direction; The traveling direction of the moving body is calculated in accordance with the second traveling speed calculated by the speed computing unit based on the reception signal from the antenna when the radio wave is radiated in the direction 2, and the result is supplied to the pan head control unit. . Therefore, in the radar system of the present invention, the direction of the moving object detected by the radar means is always based on the traveling direction of the moving object.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a block diagram showing an example of a radar system according to the present invention. The radar system 2 is mounted on an automobile as a moving body, and includes a millimeter wave radar unit 4, a calculation unit 8 (CPU), and a camera platform 70. In this embodiment, the millimeter-wave radar unit 4 and the arithmetic unit 8 constitute a radar unit according to the present invention. As described in more detail later, the millimeter-wave radar unit 4 has a millimeter-wave band whose frequency changes with time. To the front of the own vehicle to receive a reflected wave from a preceding vehicle (target) traveling in front of the own vehicle, generate a beat signal, and supply a signal representing the frequency analysis result to the arithmetic means 8. . Then, the calculating means 8 detects the azimuth of the preceding vehicle (that is, the azimuth angle) based on the signal from the millimeter wave radar unit 4 with reference to the front direction of the antenna. Further, the millimeter wave radar unit 4 and the arithmetic unit 8 constitute a traveling direction detecting unit according to the present invention, and the arithmetic unit 8 is based on a signal from the millimeter wave radar unit 4 as described in more detail later. Calculate the traveling direction of the own vehicle.

The millimeter wave radar unit 4 includes a transmitting unit 10 and a receiving unit 12. The transmitting unit 10 includes a triangular wave generator 14, an oscillator 16, a splitter 18 (H), a switch 20 (TXSW),
The receiving unit 12 includes an amplifier 22 and a switch 24.
(RXSW), mixers 26, 28, 30, selector 3
2. It is composed of an A / D converter 34 and a frequency analyzer 36 (FFT).

The triangular wave generator 14 of the transmitting unit 10 generates a triangular wave signal based on the timing signal from the timing control circuit 38, and the oscillator 16 of the transmitting unit 10 periodically generates a triangular wave signal based on the triangular wave signal generated by the triangular wave generator 14. As time passes, a transmission signal is generated whose frequency gradually increases and decreases. The transmission signal is output to the switches 20 and 24 by the branching unit 18, and the switching units 20 and 24 output the transmission signal by sequentially switching from the output terminals 40, 42 and 44 according to the timing signal from the timing control circuit 38. I do. The amplifier 22 amplifies these transmission signals to a required level, and outputs the signals to the antennas 48, 50, and 52 through the circulator 46.

As shown in FIG. 2, the antennas 48, 50, and 52 are arranged in a horizontal row at intervals and emit radio waves having substantially the same intensity. The central antenna 50 emits a radio wave in front of it to form a beam 51, and the antennas 48 and 52 on both sides radiate a radio wave in a direction slightly away from the beam 51 to form a beam 4.
9 and 53 are formed. In FIG. 2, the center line 54 of the beam 51 is substantially orthogonal to the arrangement direction of the antennas 48, 50, 52, and the beams 49,
It is the center line of a beam (not shown) obtained by combining 51 and 53. The direction of the center line 54 is the front direction of the antenna. The antennas 48, 50 and 52 are mounted on a head 70 mounted on the vehicle.
Is provided with a motor, and swings the antenna in a substantially horizontal plane and a substantially vertical plane based on a control signal from the calculating means 8.

On the other hand, the mixers 26, 28,
The signals received from the antennas 48, 50, and 52 are input to the circulator 30 through the circulator 46, respectively.
Transmission signals are input from output terminals 40, 42 and 44 of the switch 24. Then, each of the mixers 26, 28, 30
Generates a beat signal by mixing the reception signal and the transmission signal, and supplies the beat signal to the selector 32. Selector 32
Selects these beat signals by sequentially switching them based on the timing signal from the arithmetic means 8 and supplies them to the A / D converter 34. The A / D converter 34 converts the beat signal from the selector 32 into a digital signal and outputs the digital signal to the frequency analyzer 36. The frequency analyzer 36 performs frequency analysis on the digitized beat signal. A signal representing the signal amplitude for each signal frequency and a signal representing the reception intensity are generated and output to the calculating means 8.

The arithmetic means 8 is constituted by, for example, a microcomputer. As will be described in detail later, the operation means according to the present invention calculates the traveling direction of the vehicle,
0, and calculates the azimuth of the preceding vehicle based on the traveling direction of the own vehicle. The calculating means 8 also calculates the distance to the preceding vehicle based on the center frequency of the frequency spectrum based on the signal from the frequency analyzer 36, and calculates the traveling speed of the preceding vehicle from the frequency displacement due to the Doppler effect.

Next, the operation of the radar system 2 configured as described above will be described. 3A and 3B are timing charts showing the operation of the radar system 2, and FIG. 4 is a flowchart showing the operation of the radar system 2. Hereinafter, these drawings will be referred to as appropriate. First, an operation for detecting the azimuth of the preceding vehicle based on the front direction of the antenna will be described. In this case, the calculation means 8 outputs a control signal to the camera platform 70, and
The swing direction of the camera platform 70 in a substantially vertical plane of the camera platform 70 is set so that radio waves are emitted from 8, 50, and 52. The timing control circuit 38 outputs a timing signal to the triangular wave generator 14 at a constant cycle based on the control signal from the calculating means 8, and the triangular wave generator 14 has a cycle having a period as shown in FIG. A triangular wave signal ts which is equal to the cycle of the timing signal and whose amplitude changes in a period Tm in each cycle is generated. The oscillator 16 periodically increases the frequency with time based on the triangular wave signal ts generated by the triangular wave generator 14 and gradually increases and decreases the transmission signal (F).
M modulated signal).

The transmission signal is supplied to the switch 2 by the branch 18.
0, and the switch 20 sequentially switches from the output terminals 40, 42, and 44 according to the timing signal from the timing control circuit 38 and outputs the transmission signal, as shown in FIG. The amplifier 22 amplifies these transmission signals to a required level, and outputs the signals to the antennas 48, 50, and 52 through the circulator 46. As a result, radio waves are sequentially emitted from the antennas 48, 50, and 52 in the directions shown in FIG.

If another vehicle is present in front of the own vehicle, the radio waves radiated by the antennas 48, 50 and 52 are reflected by the preceding vehicle, and the antennas 48, 50 and 52 receive the reflected waves respectively. Then, each received signal is input to each of the mixers 26, 28, 30 through the circulator 46.
To each of the mixers 26, 28, and 30, a transmission signal is input from an output terminal 40, 42, and 44 of the switch 24 together with each reception signal. The switch 24 includes a timing control circuit 38
When the switch 20 is outputting the transmission signal to the output terminal 40 based on the timing signal from the switch 20, the switch 20 outputs the transmission signal to the output terminal 40 of the switch 24 and the output terminal 42, 44. When it is, the transmission signal is output to the output terminals 42 and 44 of the switch 24, respectively. As a result, each of the mixers 26, 28, and 30 mixes the received signal and the transmitted signal to generate a beat signal, and supplies the beat signal to the selector 32 at the timing shown in FIG. Selector 32
Selects these beat signals by sequentially switching them based on the timing signal from the arithmetic means 8 and supplies them to the A / D converter 34.

The A / D converter 34 is connected to the selector 32
Is converted into a digital signal and output to the frequency analyzer 36. The frequency analyzer 36 performs a frequency analysis on the digitized beat signal, and outputs a signal representing a signal amplitude for each signal frequency. And a signal representing the received signal strength is generated and output to the calculating means 8.

As described above, since the switches 20 and 24 switch the terminal for outputting the transmission signal based on the timing signal from the timing control circuit 38, the antennas 48, 50 and 52 emit radio waves in order. , And receives the reflected wave. Then, the calculating means 8 determines whether each of the antennas 48, 5
Each time transmission and reception is performed at 0 and 52, the frequency analyzer 36
Detects the azimuth of the preceding vehicle on the basis of the signal indicating the reception intensity output from the vehicle. That is, for example, when a vehicle ahead is present at the position 62 in FIG. 2, the signal received by the antenna 48 is the strongest, and the signal received by the antenna 52 is the weakest. The calculating means 8 detects the azimuth of the preceding vehicle on the basis of such a difference in reception strength between the antennas.

The calculating means 8 calculates the distance to the preceding vehicle based on the center frequency of the frequency spectrum based on the signal from the frequency analyzer 36 in addition to the direction of the preceding vehicle. The traveling speed of the preceding vehicle is calculated from the displacement amount.

Next, the traveling direction of the own vehicle is detected and the pan head 70 is detected.
The operation when controlling is described. FIG. 4 is a flowchart showing an operation in the case where the traveling direction of the own vehicle is detected and the camera platform 70 is controlled, and the drawings will be appropriately referred to below. When detecting the traveling direction of the vehicle, the calculating means 8 outputs a control signal to the camera platform 70 to swing the camera platform 70 slightly downward (step S1), as shown in the schematic diagram of FIG. As described above, the antennas 48, 50, and 52 emit the radio wave 74 toward the ground 72 and receive the reflected wave from the ground 72.

The arithmetic means 8 controls the triangular wave generator 14 through the timing control circuit 38 and stops its operation. As a result, a DC voltage having a constant amplitude is output from the triangular wave generator 14 as shown in FIG.
Then, the oscillator 16 outputs a transmission signal having a constant frequency.
In such a state, each unit of the millimeter wave radar unit 4 operates as described above, and the transmission signal output from the oscillator 16 is output to the switch 20 by the splitter 18, and the switch 20
As shown in (B), the transmission signal having the duration Ts is output by sequentially switching from the output terminals 40, 42, and 44 according to the timing signal from the timing control circuit 38. As a result, from the antennas 48, 50, 52,
A radio wave 74 having a constant frequency is emitted. Antennas 48, 5
The radio waves 74 radiated by the antennas 0 and 52 are reflected on the ground in front of the own vehicle because the antennas are directed slightly downward, and the antennas 48, 50 and 52 receive the reflected waves, respectively (step S2). Then, each received signal is transmitted to the circulator 4
6, the mixer 26, 28, 30 generates a beat signal in the same manner as described above, and supplies the beat signal to the selector 32 at the timing shown in FIG. I do. The selector 32 sequentially switches and selects these beat signals based on the timing signal from the arithmetic means 8, and supplies them to the A / D converter 34.
The A / D converter 34 converts the beat signal from the selector 32 into a digital signal and outputs the digital signal to the frequency analyzer 36. The frequency analyzer 36 performs a frequency analysis on the digitized beat signal, and Is output to the calculating means 8.

The calculating means 8 operates as a speed calculating means according to the present invention, checks the center frequency of the frequency spectrum based on the signal from the frequency analyzer 36, and calculates the center frequency of the own vehicle from the displacement of the frequency due to the Doppler effect. The traveling speed is calculated (Step S3). As described above, the switches 20, 2
Since the terminal 4 switches the terminal for outputting the transmission signal based on the timing signal from the timing control circuit 38, the antennas 48, 50, and 52 sequentially emit the radio wave 74 and receive the reflected wave (step S4). ). Then, every time the transmission / reception is performed by each of the antennas 48, 50, and 52 (step S2), the calculating means 8 sets the frequency analyzer 3
The traveling speed of the own vehicle is calculated on the basis of the signal output by 6 (step S3).

Here, the running speed of the own vehicle calculated by the arithmetic means 8 every time transmission / reception is performed by each antenna is different from the actual running speed of the own vehicle. The reason is that the directions of the antennas 48 and 52 are inclined with respect to the front direction of the antenna, and since the front direction of the antenna is usually deviated from the traveling direction, the radio waves 74
Is not coincident with the traveling direction. Here, when transmission / reception is performed by the antenna 48, the calculating means 8
Let V2 be the running speed calculated by the computer, and let V3 be the running speed calculated by the calculating means 8 when transmission / reception is performed by the antenna 52.

FIG. 6 is a schematic diagram for explaining a method of calculating the traveling direction of the own vehicle based on the calculated traveling speed of the own vehicle. As shown in this figure, the angle formed between the direction of the beam 51 and the direction of the beam 49, the angle formed between the direction of the beam 51 and the direction of the beam 49, and the direction of the beam 51 (the front direction of the antenna) are referred to. Assuming that the azimuth angle of the traveling direction is Ψ and the actual traveling speed of the vehicle 80 is V0, V2
= V0cos (Φ + Ψ), V3 = V0cos (Φ-Ψ)
By solving this simultaneous equation, the following equation representing the azimuth Ψ of the traveling direction based on the front direction of the antenna is obtained.

[0024]

Ψ = Acttan [(1−Va / Vb) / ｛t
anΦa · (1 + Va / Vb)｝] The calculating means 8 operates as a running direction calculating means here, and calculates the azimuth の of the running direction of the vehicle based on the front direction of the antenna based on this formula (step S5). ). The calculating means 8 thereafter operates as a pan head control means according to the present invention, and outputs a control signal to the pan head 70 based on the traveling direction of the vehicle based on the front direction of the antenna obtained as described above. Then, the camera platform 70 is swung in the horizontal plane by Ψ. As a result, the antenna front direction is correctly matched with the traveling direction of the vehicle (step S6).
Thereafter, the calculating means 8 controls the camera platform 70 to return the direction of the antenna to almost horizontal, and in this state, the azimuth of the preceding vehicle calculated by the calculating means 8 as described above is determined by the traveling direction of the own vehicle. It is the direction of the preceding vehicle based on the reference.

Therefore, for example, when the driving vehicle is desirably traveling at a relatively high speed and no other automobile is traveling in front of the own vehicle, the radar system 2
, Once the operation of matching the front direction of the antenna with the traveling direction of the own vehicle is performed, the azimuth angle of the preceding vehicle calculated by the calculating means 8 is always based on the running direction of the own vehicle. It becomes the azimuth of the preceding vehicle. Therefore, in this embodiment, when the antenna is mounted on the own vehicle, the direction of the antenna does not need to be set with particularly high precision as in the related art, and the mounting of the antenna can be performed extremely easily and in a short time.

The azimuth of the preceding vehicle, the distance to the preceding vehicle, and the traveling speed of the preceding vehicle obtained by the arithmetic means 8 are supplied to, for example, an alarm determination unit and an automatic driving control unit (not shown). It can be used for issuing an alarm to a driver or controlling a steering mechanism, an accelerator, a brake and the like of an automobile to perform automatic driving.

In this embodiment, the calculating means 8 calculates the calculated
Based on the traveling direction of the vehicle based on the front direction of the antenna, a control signal is output to the camera platform 70 to swing the camera platform 70 by Ψ in the horizontal plane, as shown in the flowchart of FIG. After the swing control of the camera platform 70 (step S
6) The traveling direction of the own vehicle is again determined based on the front direction of the antenna, and the detection of the traveling direction and the camera platform 7 are performed until the difference (deviation amount) between the front direction of the antenna and the traveling direction is within an allowable range.
It is also effective to adopt a configuration in which the control of 0 is repeated (step S7). In such a configuration, the difference between the front direction of the antenna and the traveling direction is always within the allowable range, so that the direction of the preceding vehicle can be detected more accurately. In FIG. 7, the same steps as those in the flowchart of FIG. 4 are denoted by the same reference numerals. Further, in the present embodiment, the total number of antennas is three, but the number of antennas is not limited to this, and may be two or four or more.

Further, in this embodiment, when measuring the traveling speed of the own vehicle with the antenna pointing downward, radio waves having a constant frequency are emitted. However, similarly to the case of detecting the direction of the preceding vehicle, a modulated wave is emitted. It is also possible to use. However, in this case, the transmission time in each cycle becomes slightly shorter as can be seen by comparing (A) and (B) in FIG.
m), from the viewpoint of emphasizing the measurement accuracy, it is desirable to use no modulation when measuring the traveling speed as in the present embodiment. If the transmission frequency is f0, the light speed is c, and the traveling speed is V, the Doppler frequency fd is fd = 2V * f0
/ C, the speed accuracy δV is δV = c / (2f0
Ts). For example, when f0 is 60 GHz, if Ts is 10 ms, the speed accuracy is 1 km / h. Further, in this embodiment, when detecting the traveling direction of the own vehicle, the antenna is switched slightly downward, but the direction of the antenna may be always constant in the vertical direction. Even with such a configuration, the reflected wave from the ground can be detected depending on the position of the antenna, the vertical direction of the antenna, or the width of the beam radiated from the antenna in the vertical direction, and the traveling direction of the vehicle Can be detected.

[0029]

As described above, in the radar system of the present invention, the radar means mounted on the moving body detects the direction of the target in front of the moving body with reference to the front direction of the antenna.
On the other hand, the traveling direction detecting means detects the traveling direction of the moving body based on the front direction of the antenna. Then, the pan head control means outputs a control signal based on the traveling direction of the moving body detected by the traveling direction detecting means, and controls the pan head so that the front direction of the antenna coincides with the traveling direction of the moving body. Here, in a state where there is no target such as another moving body ahead, the radar means radiates radio waves from the antenna in at least first and second directions having different directions and receives the radio waves reflected on the ground. As a result, the speed calculating means of the traveling direction detecting means, because the frequency of the received signal has changed due to the Doppler effect, the frequency of the received signal,
The traveling speed of the moving object can be calculated based on the difference from the frequency of the radio wave emitted by the antenna. The traveling direction calculating means of the traveling direction detecting means includes: a first traveling speed calculated by the speed computing means based on a reception signal from the antenna when the antenna radiates radio waves in the first direction; The traveling direction of the moving body is calculated in accordance with the second traveling speed calculated by the speed computing unit based on the reception signal from the antenna when the radio wave is radiated in the direction 2, and the result is supplied to the pan head control unit. . Therefore, in the radar system of the present invention, the direction of the moving object detected by the radar means is always based on the traveling direction of the moving object. Therefore, when the antenna is mounted on the moving body, the direction of the antenna does not need to be set with particularly high precision as in the related art, and the mounting of the antenna can be performed extremely easily and in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a radar system according to the present invention.

FIG. 2 is a schematic diagram illustrating a beam pattern of a radio wave emitted by an antenna included in the radar system of FIG. 1;

FIG. 3A is a timing chart showing an operation when detecting the traveling direction of a preceding vehicle, and FIG. 3B is a timing chart showing an operation when detecting the traveling direction of the own vehicle.

FIG. 4 is a flowchart showing an operation in a case where the traveling direction of the own vehicle is detected to control the camera platform.

FIG. 5 is a schematic diagram showing a direction of a radio wave beam emitted when detecting a traveling direction of the own vehicle.

FIG. 6 is a schematic diagram for explaining a method of calculating the traveling direction of the own vehicle based on the calculated traveling speed of the own vehicle.

FIG. 7 is a flowchart showing an operation in a case where repetitive control is performed to keep a difference between the front direction of the antenna and the traveling direction within an allowable range. [Brief description of drawings]

[Explanation of symbols]

2 ... Radar system, 4 ... Millimeter wave radar unit, 6 ...
Running direction detecting means, 8 arithmetic means, 14 triangular wave generator, 16 oscillator, 20, 24, switcher, 26,
28, 30 ... mixer, 32 ... selector, 34 ... A
/ D converter, 36 frequency analyzer, 48, 50, 52
…… antenna, 70 …… head.

Claims (9)

[Claims] 1. Radar means for detecting a direction of a target in front of a moving object based on a front direction of an antenna; running direction detecting means for detecting a running direction of the moving body based on a front direction of the antenna; A head mounted on the moving body, supporting the antenna, and swinging the antenna in a substantially horizontal plane based on a control signal; and based on the running direction of the moving body detected by the running direction detecting means. Head control means for outputting the control signal and controlling the head so that the front direction of the antenna coincides with the traveling direction of the moving body, wherein the antenna has an azimuth based on the front direction of the antenna. Radiating radio waves in at least first and second directions different from each other to receive a reflected wave, wherein the traveling direction detecting means comprises: a frequency of a signal received from the antenna; Speed calculating means for calculating a traveling speed of the moving object based on a difference between the frequency of the radio wave emitted by the antenna and a signal received from the antenna when the antenna emits a radio wave in the first direction. A second running speed calculated by the speed calculating means based on a first running speed calculated by the speed calculating means and a signal received from the antenna when the antenna radiates radio waves in the second direction. A traveling direction calculating means for calculating a traveling direction of the moving body according to a speed. 2. The travel direction detection means and the pan head control means repeatedly detect the travel direction until the difference between the front direction of the antenna and the travel direction of the moving body is within an allowable range. The radar system according to claim 1, which controls a camera platform. 3. The azimuths of the first and second directions based on the front direction of the antenna have different signs and substantially equal absolute values. The absolute value of the azimuth is Φ, and the first and second azimuths are Φ. When the traveling speed of the moving object is Va and Vb, respectively, and the traveling direction of the moving body is 方向, the traveling direction calculation means calculates the equation Ψ = Act
an [(1−Va / Vb) / ｛tanΦ · (1 + Va /
The radar system according to claim 1, wherein the traveling direction of the moving body is calculated by Vb)｝]. 4. The pan head swings the antenna even in a substantially vertical plane, and when detecting a traveling direction of the moving body, the pan head control means outputs the control signal to control the pan head. The radar system according to claim 1, wherein the radar system swings slightly downward. 5. The antenna is configured by arranging a plurality of antennas including first and second antennas that radiate radio waves in the first and second directions in a horizontal line at intervals. Emit radio waves in different directions,
2. The radar system according to claim 1, wherein said radar means radiates radio waves having substantially the same intensity from each antenna and detects the azimuth of said target based on a difference in intensity of reflected waves received by each antenna. 6. The radar system according to claim 5, wherein the total number of antennas is three, and the third antenna emits a radio wave in an intermediate direction between the first and second directions. 7. The radar device according to claim 1, wherein said radar means comprises:
7. The radar system according to claim 6, wherein the antennas are sequentially switched to emit the radio waves and receive the reflected waves. 8. The radar system according to claim 1, wherein the antenna radiates the radio wave in a millimeter wave band. 9. The radar means, when detecting the azimuth of the target, radiates the radio wave whose frequency changes according to a change in the amplitude of a triangular wave having a predetermined period from the antenna, and changes a traveling direction of the moving body. The radar system according to claim 1, wherein upon detection, the radio wave having a constant frequency is radiated from the antenna.