JP2012159349A - Antenna device, lader apparatus and vehicle-mounted lader system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device that can cover a broad detection area of even surpassing 180° in spite of being formed over a single board, a lader apparatus utilizing the antenna device and a vehicle-mounted lader system.SOLUTION: In an antenna device, a planar radiation antenna part 3 whose main direction of radiation is the facial direction of an antenna board 6 and a horizontal radiation antenna part 4 whose main direction of radiation is the end direction of the antenna board 6 are formed in different pattern formation layers of the antenna board 6; in this way, the directionality of the horizontal radiation antenna part 4 can be shifted closer to a component mounting face 6b than when the two antenna parts 3 and 4 are formed in the same pattern formation layer, with the result that the detection area that can be covered by the single antenna board 6 can be broadened in angle (to, for instance, 180° or more).

Description

  The present invention relates to an antenna device used for transmission / reception of electromagnetic waves, a radar device configured using the antenna device, and an in-vehicle radar system configured using the radar device.

  Conventionally, as a technique for realizing a wide detection area in a radar apparatus, a planar radiation antenna (such as a broadside array antenna) that radiates electromagnetic waves in a direction perpendicular to the pattern formation surface of the substrate, Known is one in which a horizontal radiation antenna (an endfire array antenna or the like) that radiates electromagnetic waves in a direction parallel to a pattern formation surface is formed on the same pattern formation surface of the same substrate (for example, a patent) Reference 1).

  On this antenna substrate, a plurality of planar radiation antennas (hereinafter collectively referred to as a planar radiation antenna group) are arranged in a line, and horizontal radiation is provided at both ends of the planar radiation antenna group in the arrangement direction. An antenna is arranged. The plane radiation antenna group forms a plurality of beams having different radiation directions along the antenna arrangement direction, and the horizontal radiation antenna covers an area (detection area) covered by the beam of the plane radiation antenna group. It is set so that the beam is directed outward (a detection area is set).

JP 2007-49691 A

  However, in the antenna substrate described in Patent Document 1, although the beam direction (radiation direction) of the horizontal radiation antenna is directed outward from the detection area of the planar radiation antenna group, it is at most along the pattern formation surface. There is a problem that it is not possible to cover a wider detection area because the limit is to set in the direction.

  In order to solve the above problems, the present invention provides an antenna device capable of covering a wide detection area exceeding 180 ° despite being formed on a single substrate, and a radar device using the antenna device An object is to provide an on-vehicle radar system.

The antenna device of the present invention made to achieve the above object is configured using a substrate having two or more pattern forming layers.
Of the pattern formation layers, the outer layer, which is a pattern formation layer in which one surface is in contact with the insulating layer and the other surface is opened, has a stacking direction of the pattern formation layers (that is, a direction perpendicular to the surface of the pattern formation layer). ), And a planar radiation antenna section is formed, which is composed of a plurality of planar radiation unit antennas that radiate electromagnetic waves toward the surface.

  Further, the pattern forming layer different from the one in which the planar radiation antenna portion is formed has at least one end portion in the antenna arrangement direction, which is the arrangement direction of the planar radiation unit antennas, in the antenna arrangement direction. A horizontal radiating antenna unit including at least one horizontal radiating unit antenna that radiates electromagnetic waves is formed.

  According to the antenna device configured as described above, the horizontal radiation antenna unit is formed in a pattern forming layer different from that of the planar radiation antenna. Compared with the case where it forms in the same pattern formation layer, it can face to the back side direction with respect to the formation surface of the planar radiation antenna part more.

  The horizontal radiating antenna portion may be formed in an outer layer different from the horizontal radiating antenna portion as described in claim 2, or both sides may be formed as insulating layers as described in claim 3. You may form in the inner layer which is a pattern formation layer which faces.

  Further, as described in claim 4, the power supply to the horizontal radiation antenna unit is performed between the pattern formation layer in which the horizontal radiation antenna unit is formed and the pattern formation layer in which the planar radiation antenna unit is formed. It is desirable to perform from the pattern forming layer (inner layer) located.

In this case, since the leakage radiation of the radio wave from the feeder line can be reduced, the disturbance of the directivity of the horizontal radiation antenna unit due to the leakage radiation from the feeder line can be suppressed.
By the way, as described in claim 5, the planar radiation antenna unit includes a transmission antenna unit dedicated for transmission and a reception antenna unit dedicated for reception arranged along the antenna arrangement direction, each of which is a plurality of planar radiation components. You may be comprised with the unit antenna.

  In addition, the horizontal radiation antenna unit includes a transmission antenna unit dedicated for transmission and a reception antenna unit dedicated for reception arranged in a direction orthogonal to the antenna arrangement direction as described in claim 6. , Each may be composed of at least one horizontal radiation unit antenna.

  Thus, by performing transmission and reception of electromagnetic waves by the dedicated transmission antenna unit and reception antenna unit, respectively, an apparatus can be configured without using expensive parts such as a circulator that separates a transmission signal and a reception signal. it can.

  In the antenna device of the present invention, the unit antenna for plane radiation is configured by a plurality of patch antennas arranged in one or a plurality of columns along a direction orthogonal to the antenna arrangement direction, as described in claim 7. May be. In this case, the beam width of the unit antenna for plane radiation can be reduced in the arrangement direction of the patch antennas.

  Further, as the horizontal radiating unit antenna, for example, a tapered slot antenna may be used as described in claim 8. In this case, since the unit antenna for horizontal radiation can be increased in bandwidth, it can be suitably used for ultra wideband (UWB) modulation.

  In addition, in the outer layer different from the horizontal radiating antenna unit, as described in claim 9, the electrons constituting the transmitting unit and the receiving unit that transmit and receive electromagnetic waves via the planar radiating antenna unit and the horizontal radiating antenna unit are provided. Components may be mounted. In other words, the horizontal radiation antenna section may be formed on the component mounting surface of the substrate. In this case, the antenna device can be reduced in size.

  Next, a radar apparatus according to a tenth aspect is configured using the antenna apparatus according to any one of the first to ninth aspects, and a transmission unit is a plane that forms the antenna apparatus. Either one of the radiating antenna unit and the horizontal radiating antenna unit is selected to transmit an electromagnetic wave, and the receiving unit is one of the planar radiating antenna unit and the horizontal radiating antenna unit constituting the antenna device. Select one to receive electromagnetic waves. And a signal processing part selects the antenna part used for transmission / reception, transmits an electromagnetic wave via a transmission part, and performs the process which detects a target based on the signal acquired via the receiving part.

  According to the radar apparatus of the present invention configured as described above, by using the antenna apparatus described above, a target can be detected using a wide angle range exceeding, for example, 180 ° as a detection area.

  In addition, as described in claim 11, the transmitting unit transmits the planar radiating antenna unit by controlling the amplitude and phase of a transmission signal supplied to each of the planar radiating unit antennas used for transmitting electromagnetic waves. It is desirable to have an amplitude / phase control circuit that changes the directivity of electromagnetic waves.

  In addition, as described in claim 12, the receiving unit individually supplies a reception signal from each of the planar radiation unit antennas used for receiving electromagnetic waves to the signal processing unit, and the signal processing unit receives each received signal. It is desirable that the phase information is used to execute processing (monopulse, DBF, MUSIC, etc.) for estimating the arrival direction of electromagnetic waves (controlling reception directivity).

  Furthermore, as described in claim 13, when the transmission unit transmits electromagnetic waves via the planar radiation antenna unit, the reception unit also receives the electromagnetic waves via the planar radiation antenna unit, and the transmission unit When the electromagnetic wave is transmitted through the horizontal radiation antenna unit, the operation of the transmission unit and the reception unit may be controlled so that the reception unit also receives the electromagnetic wave through the horizontal radiation antenna unit. In this case, the target can be detected using the detection area of each antenna unit to the maximum.

  Not limited to this, the transmission unit transmits electromagnetic waves via the planar radiation antenna unit, and the reception unit receives electromagnetic waves via the horizontal radiation antenna unit, or conversely, the transmission unit is the horizontal radiation antenna unit. The operation of the transmission unit and the reception unit may be controlled such that the electromagnetic wave is transmitted through the reception unit and the reception unit receives the electromagnetic wave through the planar radiation antenna unit. However, in this case, it is necessary to configure the detection area of the horizontal radiating antenna unit and the detection area of the horizontal radiating antenna unit to partially overlap, and an area where the detection areas overlap is detected. .

  In the radar apparatus of the present invention, the transmitter and the receiver are, as described in claim 14, a pulse wave mode that is an operation mode for transmitting and receiving pulse waves, and a continuous wave mode that is an operation mode for transmitting and receiving continuous waves. You may have.

  In this case, as described in claim 15, the transmitter and the receiver operate in a continuous wave mode when the planar radiation antenna unit is used, and pulse when the horizontal radiation antenna unit is used. It is conceivable to control to operate in the wave mode.

  If a pulse that is UWB (ultra-wideband) modulated is used in the pulse wave mode, a target can be detected with high distance resolution. In the continuous wave mode, an FMCW wave, a multi-frequency CW wave, or the like can be used. In particular, when a CW wave that is not frequency-modulated is used, a target whose relative speed is 0 is not detected. For example, when the vehicle on which the device is mounted is stopped, only surrounding moving targets are detected. It can be suitably used in applications such as when detection is desired.

  Next, an on-vehicle radar system according to a sixteenth aspect includes two radar devices according to the fifteenth aspect. Then, the detection area of the planar radiation antenna unit is the first area, the detection area of the horizontal radiation antenna unit is the second area, and one of the two radar devices has the first area on the right rear side of the vehicle and the second area. Is located on the right side of the vehicle, and the other is installed on the vehicle so that the first area is located on the left rear side of the vehicle and the second area is located on the left side of the vehicle.

In this way, a wide range extending from the rear to both sides of the vehicle can be covered with the two radar devices, and the configuration of the in-vehicle radar system can be simplified.
The first area is, for example, a rear approaching vehicle detection area that is set to detect a vehicle approaching from behind, or a vehicle that is about to cross the rear of the vehicle when reversing. The second area is, for example, as described in claim 18 for detecting a vehicle existing at a position that becomes a blind spot of the driver. It is conceivable that the blind spot vehicle detection area is set to “1”.

  Further, in the in-vehicle radar system of the present invention, it is desirable that the two radar devices include a system control unit that operates simultaneously in different operation modes as described in claim 19.

  In this way, not only can the two radar devices be operated efficiently, but also interference between the two radar devices can be suppressed.

The block diagram which shows the whole structure of a radar apparatus. Explanatory drawing which shows the pattern of the antenna part for plane radiation formed on the antenna substrate, and the antenna part for horizontal radiation. Explanatory drawing which shows the structure of an antenna board | substrate, and the beam radiation direction of the antenna formed in the antenna board | substrate. The graph which shows the modulation pattern of a transmission signal. Explanatory drawing which shows schematic structure of a vehicle-mounted radar system, and the arrangement | positioning state of an antenna board | substrate. The table | surface which shows the content of the detection mode in a vehicle-mounted radar system. Explanatory drawing which shows the schematic position of a blind spot vehicle detection area and a back approaching vehicle detection area. Explanatory drawing which shows the schematic position of a blind spot vehicle detection area and a crossing vehicle detection area at the time of reverse. The flowchart which shows the content of a system control process. The flowchart which shows the content of a blind spot vehicle detection warning process. The flowchart which shows the content of back approaching vehicle detection alarm processing. The flowchart which shows the content of the crossing vehicle detection warning process at the time of reverse. The flowchart which shows the content of the system control process in 2nd Embodiment. Explanatory drawing which shows the other example of a pattern of the antenna part for plane radiation formed in the antenna board | substrate, and the antenna part for horizontal radiation. Explanatory drawing which shows the other structural example of the unit antenna for horizontal radiation.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
<Overall configuration>
FIG. 1 is a block diagram illustrating an overall configuration of a radar apparatus 1 according to an embodiment.

  As shown in FIG. 1, the radar apparatus 1 includes planar radiation transmitting antenna groups 31 and n (m (m is an integer of 2 or more) planar radiation unit antennas SBi (i = 1 to m)). n is an integer greater than or equal to 2) the planar radiation antenna unit 3 composed of the planar radiation receiving antenna group 32 composed of the number of planar radiation unit antennas RBj (j = 1 to n), and a single horizontal radiation unit. It consists of a horizontal radiation transmitting antenna 41 composed of an antenna SE and a horizontal radiation receiving antenna 42 composed of a single horizontal radiation unit antenna RE, so that the main radiation direction is different from that of the planar radiation antenna section 3. The horizontal radiating antenna unit 4 is provided.

  Further, the radar apparatus 1 includes a transmitter 10 that transmits electromagnetic waves (radar waves) via a plane radiation transmission antenna group 31 and a horizontal radiation transmission antenna 41, a plane radiation reception antenna group 32, and a horizontal radiation reception antenna. The receiver 20 that receives electromagnetic waves (reflected waves) via 42 and a well-known microcomputer are mainly configured. The transmitter 10 and the receiver 20 are provided with a modulation signal M, a transmission control signal CS, and a reception described later. A control circuit 5 that supplies a control signal CR, a transmission-side pulse control signal CPs, and a reception-side pulse control signal CPr, and as a result, performs various signal processing based on a beat signal B generated by the receiver 20; Yes.

<Antenna substrate>
2A and 2B are explanatory views showing the arrangement of patterns on the antenna substrate 6 on which the planar radiation antenna portion 3 and the horizontal radiation antenna portion 4 are formed. FIG. 2A shows the antenna formation surface 6a, and FIG. The mounting surface 6b is represented. 3A is a schematic diagram showing a cross section of the antenna substrate 6 in an enlarged manner in the plate thickness direction (vertical direction in the figure), and FIG. 3B is an explanation showing the main radiation direction of each antenna section. FIG.

  As shown in FIG. 3A, the antenna substrate 6 is configured as a so-called multilayer substrate having six pattern forming layers and five insulating (dielectric) layers that insulate each pattern forming layer. Yes.

  Hereinafter, the four pattern forming layers in contact with the insulating layer on both sides are referred to as the inner layer, and the two pattern forming layers in which only one surface is in contact with the insulating layer and the other surface is open to the outside are referred to as the outer layer. Of the two surfaces of the antenna substrate 6 on which the outer layer is formed, one is referred to as an antenna formation surface 6a and the other as a component placement surface 6b.

  Further, among the pattern forming layers of the antenna substrate 6, the inner layer facing the outer layer formed on the antenna forming surface 6a with one insulating layer interposed therebetween is for the patch antenna constituting the planar radiation antenna portion 3. The ground pattern 61 is formed. In addition, a feed line (microstrip line) 62 to the horizontal radiation antenna unit 4 is formed on the inner layer opposed to the outer layer formed on the component mounting surface 6b with one insulating layer interposed therebetween. A ground pattern 63 for the feed line (microstrip line) 62 is at least a component mounting surface on the inner layer located on the antenna forming surface side 6a with one insulating layer interposed between the inner layer on which the feed line 62 is formed. It is formed at a position facing the component mounting area 6b.

  Then, on the antenna forming surface 6a of the antenna substrate 6, as shown in FIG. 2 (a), a planar radiation transmitting antenna group 31 and a planar radiation receiving antenna group 32 constituting the planar radiation antenna unit 3 are arranged side by side. Has been. Hereinafter, the arrangement direction of both antenna groups 31 and 32 is referred to as an antenna arrangement direction.

  Further, on the component mounting surface 6b of the antenna substrate 6, as shown in FIG. 2B, the horizontal radiation transmitting antenna 41 constituting the horizontal radiation antenna unit 4 is formed at one end of the antenna substrate 6 in the antenna arrangement direction. The horizontal radiation receiving antennas 42 are arranged side by side along a direction perpendicular to the antenna arrangement direction.

  The planar radiation unit antennas SB1 to SBm constituting the planar radiation transmission antenna group 31 and the planar radiation unit antennas RB1 to RBn constituting the planar radiation reception antenna group 32 are arranged in a line along the antenna arrangement direction. Is arranged.

  However, each planar radiation unit antenna SBi, RBj is composed of a plurality of patch antennas arranged in a line at equal intervals along a direction orthogonal to the antenna arrangement direction (vertical direction in the figure). The feeder lines are wired so that signals of the same phase are fed to the patch antennas constituting the same planar radiation unit antennas SBi and RBj.

Note that the patch antennas constituting the planar radiation unit antennas SBi and RBj are set in one row here, but are not limited to this, and may be arranged in a plurality of rows.
That is, as shown in FIG. 3B, the planar radiation antenna unit 3 is a so-called broad side beam in which the direction perpendicular to the antenna formation surface 6a of the antenna substrate 6 (hereinafter referred to as “plane direction”) is the main radiation direction. It is configured as an array antenna.

  On the other hand, each of the horizontal radiating transmission antenna 41 and the horizontal radiating receiving antenna 42 constituting the horizontal radiating antenna unit 4 is configured by a tapered slot antenna having a pattern simulating a tapered slot. Is formed so that the end on the wide side is opened at the end of the antenna substrate 6.

  That is, as shown in FIG. 3B, the horizontal radiating antenna unit 4 is mainly in a direction parallel to the component placement surface 6b of the antenna substrate 6 and perpendicular to the antenna arrangement direction (hereinafter referred to as “end direction”). It is configured as a so-called endfire antenna that has a radiation direction.

  The planar radiation antenna unit 3 and the horizontal radiation antenna unit 4 are both designed to have a constant antenna gain over a wide frequency range so that ultra-wideband (UWB) modulation is possible. Yes.

<Transmitter>
Returning to FIG. 1, the transmitter 10 is configured around an oscillator that generates a high-frequency signal in the millimeter wave band, and a voltage-controlled oscillator (VCO) configured such that the oscillation frequency changes according to the modulation signal M from the control circuit 5. ) 11, an amplifier 12 for amplifying the output from the VCO 11, a branch line 13 for branching the output of the amplifier 12 into a transmission signal Ss and a local signal L, and a transmission signal Ss supplied via the branch line 13 The distributor 15 that distributes to the transmission lines connected to the unit antennas SB1 to SBm, SE constituting the transmission antenna group 31 for horizontal radiation and the transmission antenna 41 for horizontal radiation, and transmission-side pulse control from the control circuit 5 A pulse generator 14 for generating a pulse signal by conducting and blocking a transmission path from the branch line 13 to the distributor 15 according to the signal CPs, and a distributor 5 from the unit antenna SB1～SBm, and a signal control unit 16 that the amplitude and phase of the transmission signal Ss to be transmitted in the transmission lines leading to the SE, controlled according to the transmission control signal CS. The signal control unit 16 includes a phase shifter and an amplifier for each transmission path connected to the unit antennas SB1 to SBm and SE. In particular, the amplifier sets the transmission line by setting the amplification factor to zero. It is also configured to function as a switch that shuts off.

<Receiver>
The receiver 20 includes an amplifying unit 21 that individually amplifies reception signals from the unit antennas RB1 to RBn and RE that form the planar radiation receiving antenna group 32 and the horizontal radiation receiving antenna 42, and reception from the control circuit 5. In accordance with the control signal CR, one of the transmission lines connected to the unit antennas RB1 to RBn, RE is selected, and a reception switch circuit 22 that outputs a reception signal from the selected transmission line; A mixer 24 that mixes the received signal Sr with the local signal L from the branch line 13 to generate the beat signal B; an amplifier 25 that amplifies the beat signal B output from the mixer 24 and supplies the beat signal B to the control circuit 5; The transmission path of the local signal L from 13 to the mixer 24 is turned on and off according to the reception side pulse control signal CPr from the control circuit 5. More, and a pulse generator 23 for generating a pulse-like local signal L.

The transmitter 10 and the receiver 20 are designed to generate and transmit a pulse signal having a pulse width of about 1 ns, that is, a so-called ultra wideband (UWB) modulation pulse.
<Operation mode>
Next, the operation mode of the radar apparatus 1 will be described.

  Here, the operation mode for transmitting / receiving electromagnetic waves via the planar radiation antenna unit 3 is pulsed as the plane radiation mode, the operation mode for transmitting / receiving electromagnetic waves via the horizontal radiation antenna unit 4 is the horizontal radiation mode, and the transmission / reception electromagnetic wave is pulsed. An operation mode using waves is called a pulse wave mode, and an operation mode using continuous waves (FMCW waves or CW waves) as electromagnetic waves to be transmitted and received is called a continuous wave mode.

  However, the radar apparatus 1 operates according to two operation modes obtained by combining an operation mode of either the plane radiation mode or the horizontal radiation mode and an operation mode of the pulse wave mode or the continuous wave mode.

  When the operation mode is the plane radiation mode, the transmitter 10 controls the signal control unit so that the transmission signal Ss is supplied only to the planar radiation transmission antenna group 31 (unit antennas SB1 to SBm) according to the transmission control signal CS. In addition to controlling the 16 amplifiers, the phase shifter of the signal control unit 16 is controlled so that the beam formed by the planar radiation transmitting antenna group 31 is directed in the radiation direction specified by the transmission control signal CS. The Further, in the receiver 20, the reception signals from the unit antennas RB1 to RBn are sequentially and repeatedly selected according to the reception control signal CR by selecting the reception signals from the planar radiation reception antenna group 32 (unit antennas RB1 to RBn). Is supplied to the mixer 24 in a time-sharing manner.

  When the operation mode is the horizontal radiation mode, the transmitter 10 includes an amplifier of the signal control unit 16 so that the transmission signal Ss is supplied only to the horizontal radiation transmission antenna 41 (unit antenna SE) according to the transmission control signal CS. Is controlled. In the receiver 20, the reception switch circuit 22 is controlled so that only the reception signal from the horizontal radiation receiving antenna 42 (unit antenna RE) is supplied to the mixer 24 in accordance with the reception control signal CR.

  On the other hand, when the operation mode is the continuous wave mode, both the pulse generator 14 of the transmitter 10 and the pulse generator 23 of the receiver 20 operate so as to pass the transmission signal Ss and the local signal L as they are.

  Further, when the operation mode is the pulse wave mode, the pulse generator 14 of the transmitter 10 becomes longer than the time required for the electromagnetic wave to reciprocate the maximum detection distance of the radar apparatus 1 according to the transmission side pulse control signal CPs. By transmitting the transmission path from the branch line 13 to the distributor 15 for a predetermined time (for example, 1 ns) at a set constant time interval, a pulsed transmission signal Ss is generated.

  Further, the pulse generator 23 of the receiver 20 is controlled so as to conduct the transmission path from the branch line 13 to the mixer 24 for a certain period of time according to the reception side pulse control signal CPr. L is generated. However, the pulse-like local signal L is controlled so that the generation timing is delayed by the pulse width every time the pulse wave transmission is repeated and the pulse wave transmission timing is repeated. The pulse width may be set to a fixed value or may be variably set depending on conditions.

<Control circuit>
The control circuit 5 operates the transmitter 10 and the receiver 20 in the designated operation mode to execute a target detection process for detecting a target based on the beat signal B obtained from the receiver 20.

  However, when the operation mode is the pulse wave mode, the control circuit 5 supplies the modulation signal M to the VCO 11 such that the frequency of the transmission signal Ss generated by the VCO 11 is constant, as shown in FIG. To do.

  In addition, when the operation mode is the continuous wave mode, the control circuit 5 generates an FMCW wave in which the frequency of the transmission signal Ss generated by the VCO 11 repeatedly increases and decreases in a triangular shape as shown in FIG. 4B. 4 or a modulation signal M for generating a two-frequency CW wave in which the frequency of the transmission signal Ss is alternately switched in two stages as shown in FIG.

  When the operation mode is a pulse wave mode (measurement by pulse wave), the receiver 20 responds to the degree of coincidence when the reception timing of the pulse wave coincides with the transmission timing of the pulsed local signal. A beat signal B having an amplitude is output. For this reason, in the control circuit 5, as a target detection process, from the generation timing of the pulse-like local signal L when the beat signal B having the highest intensity (correlation value) is obtained to the target reflecting the pulse wave. The process of calculating the distance is executed. Since this process is a well-known process in pulse radar, the details thereof will be omitted.

That is, when the operation mode is the pulse wave mode, the distance to the target can be obtained as target information existing in the detection area by the target detection process.
When the operation mode is a continuous wave mode (measurement using an FMCW wave or a two-frequency CW wave), the receiver 20 outputs a beat signal B obtained by mixing the reception signal Sr and the local signal L. For this reason, in the control circuit 5, as a target detection process, a process for obtaining a relative speed and distance from the target is executed using a well-known technique in the FMCW radar and the two-frequency CW radar.

That is, when the operation mode is the continuous wave mode, the relative speed and distance to the target can be obtained as information on the target existing in the detection area by the target detection process.
Note that when the operation mode is the continuous wave mode, the frequency of the transmission signal Ss is not limited to the above-described FMCW wave and two-frequency CW wave, for example, as shown in FIG. ), A modulation signal M that repeatedly increases and decreases may be output to perform measurement using a multi-frequency CW wave.

  When the operation mode is the plane wave radiation mode, a beat signal B is obtained from the plane radiation receiving antenna group 32 for each of the unit antennas RB1 to RBn. For this reason, the control circuit 5 also executes a process for obtaining the arrival direction of the reflected wave, that is, the azimuth angle where the target exists, from the phase difference between the beat signals B as the target detection process. It should be noted that known methods such as monopulse, DBF, and MUSIC can be used for azimuth detection using phase difference information.

<In-vehicle radar system>
FIG. 5A is a block diagram showing an outline of an in-vehicle radar system configured using the above-described radar apparatus 1, and FIG. 5B is an explanatory diagram showing an arrangement state of the antenna substrate 6 in the vehicle.

  As shown in FIG. 5A, the in-vehicle radar system is configured using two radar devices 1 (1a, 1b), and these radar devices 1a, 1b can communicate with each other via an in-vehicle network. It is connected. Note that a function (communication control unit) that realizes communication via the in-vehicle network is included as one function of the control circuit 5.

  Then, one of the radar devices 1a and 1b is set as a master (here 1a) and the other is set as a slave (here 1b). In the master control circuit 5, in addition to the above-described target detection processing, Based on the system control processing for controlling the operation mode and operation timing of 1b and the processing results of the target detection processing of both radar apparatuses 1a and 1b, alarm processing for generating various alarms is executed.

  Further, the master 1a supplies a signal for controlling the operation mode and operation timing to the slave 1b via the in-vehicle network, acquires the detection result of the target detection process from the slave 1b, and is connected to the in-vehicle network. In addition, various types of information (for example, the vehicle speed, the position of the shift lever, the state of the direction indicator, etc.) necessary for processing are obtained from other in-vehicle devices.

  Here, the master-slave communication and the communication with other in-vehicle devices are described as being performed in the same in-vehicle network. However, both communication may be performed in separate in-vehicle networks. Good. In that case, the vehicle-mounted network that communicates with other vehicle-mounted devices may be connected only to the master.

  As shown in FIG. 5 (b), the radar apparatus 1a is arranged at the right rear corner of the vehicle, the detection area of the planar radiation antenna unit 3 is directed to the rear right of the vehicle, and the horizontal radiation antenna unit 4 The antenna substrate 6 is installed so that the detection area is directed to the right side of the vehicle so that the surface direction of the antenna substrate 6 is tilted to the left by about 30 ° from the straight forward direction of the vehicle when the rear of the vehicle is viewed from the vehicle.

  The radar apparatus 1b is arranged at the left rear corner so that the detection area of the planar radiation antenna unit 3 is directed toward the rear left side of the vehicle, and the detection area of the horizontal radiation antenna unit 4 is directed toward the left side of the vehicle. The antenna substrate 6 is installed so that the surface direction of the antenna substrate 6 is tilted to the right by about 30 ° from the vehicle's straight forward direction when the rear of the vehicle is viewed from the vehicle.

<Detection mode>
Here, FIG. 6 is a list of detection modes that define how the radar apparatus 1 is operated when the in-vehicle radar system performs target detection. FIGS. 7 and 8 are explanatory diagrams showing the approximate position of the detection area used in each detection mode.

  As shown in FIG. 6, in the in-vehicle radar system, a blind spot vehicle detection mode that is a detection mode for detecting a vehicle existing in the blind spot of the vehicle and a backward approach that is a detection mode for detecting a vehicle approaching from the rear. There is a vehicle detection mode and a reverse vehicle detection mode that is a detection mode for detecting a vehicle that is about to cross the rear of the vehicle when the vehicle is moving backward.

  Among these, in the blind spot vehicle detection mode, the radar apparatus 1 is set in the horizontal radiation mode and the pulse wave mode, and is operated in the blind spot vehicle detection area (see FIGS. 7 and 8) set on the side of the vehicle. The distance to the vehicle is determined with high accuracy.

  In the rear approaching vehicle detection mode, the radar apparatus 1 is operated in the plane emission mode and the continuous wave mode (however, the FMCW wave), so that the vehicle existing in the rear vehicle detection area (see FIG. 7) set at the rear of the vehicle. Find distance, relative speed, and azimuth.

  In the reverse crossing vehicle detection mode, the radar device 1 is operated in a plane radiation mode and a continuous wave mode (however, two CW waves), so that the reverse crossing vehicle detection area set behind the vehicle (see FIG. 8). ) To find the distance, relative speed, and azimuth angle with the vehicle.

  However, the rear vehicle detection area is set to an area centered on the end direction of the antenna board 6 so that the vehicles in the adjacent lanes can be suitably detected, while the reverse crossing vehicle detection area is relatively close to the vehicle. An area centered around a direction greatly inclined from the surface direction of the antenna substrate 6 to the end direction is set so that a vehicle or the like can be suitably detected at a close position in a wide range in the vehicle width direction.

  In addition, the detection area (directivity of the antenna) that is different between the vehicle approaching detection mode in the backward approach and the vehicle detection mode at the time of reversing when the planar radiation antenna unit 3 is used controls the phase shifter of the signal control unit 16. Is set as appropriate.

<System control processing>
Next, the contents of the system control process executed by the control circuit 5 of the master 1a will be described with reference to the flowchart shown in FIG.

This process is repeatedly executed at predetermined time intervals when the master 1a is activated.
When this process is started, in S110, the master 1a is operated in the blind spot vehicle detection mode, and the target detection process is executed according to the measurement result to thereby determine the distance from the target existing in the blind spot vehicle detection area on the right side of the vehicle. calculate.

  In S120, the master 1a is operated in the backward approaching vehicle detection mode, and the target detection process is executed in accordance with the measurement result, whereby the distance, relative speed, and direction from the target existing in the rear approaching vehicle detection area on the right side of the vehicle. Calculate the angle.

  In S130, the master 1a is operated in the reverse crossing vehicle detection mode, and the target detection process is executed according to the measurement result, thereby the distance from the target existing in the reverse crossing vehicle detection area on the right side of the vehicle, Calculate the relative speed and azimuth angle.

  In S140, the slave 1b is operated in the blind spot vehicle detection mode, and the target detection process is executed according to the measurement result, thereby calculating the distance from the target existing in the blind spot vehicle detection area on the left side of the vehicle.

  In S150, the slave 1b is operated in the backward approaching vehicle detection mode, and the target detection process is executed in accordance with the measurement result, whereby the distance, relative speed, and direction from the target existing in the backward approaching vehicle detection area on the left side of the vehicle. Calculate the angle.

  In S160, the slave 1b is operated in the reverse crossing vehicle detection mode, and the target detection process is executed according to the measurement result, thereby the distance from the target existing in the reverse crossing vehicle detection area on the left side of the vehicle, Calculate the relative speed and azimuth angle.

<Alarm processing>
Next, blind spot vehicle detection alarm processing, backward approaching vehicle detection alarm processing, backward crossing vehicle detection alarm processing executed based on information on targets existing in each detection area obtained by executing system control processing Will be described. These processes are started when the master 1a is activated.

First, the blind spot vehicle detection alarm process will be described along the flowchart shown in FIG.
When this process is started, first, in S210, it is determined whether or not the host vehicle is in a stopped state.

  Whether or not the vehicle is stopped is determined based on vehicle speed and shift lever position information acquired via the in-vehicle network. Specifically, the vehicle speed is zero and the shift lever is at the parking position. It is determined that the vehicle is in a stopped state.

  In S220, based on the detection results in the previous S110 and S140, it is determined whether or not a vehicle (target) is detected in the blind spot vehicle detection area. If detected, the process proceeds to S230 and the alarm is turned on. Then, the process returns to S210. Note that the alarm may be configured such that the manner of ringing changes according to the distance from the detected target.

  On the other hand, if a vehicle is not detected in the blind spot vehicle detection area, the process proceeds to S240, and if the alarm is ON, this is switched to OFF, and if the alarm is OFF, nothing is done, S210. Return to.

Next, the rear approaching vehicle detection alarm process will be described along the flowchart shown in FIG.
When this process is activated, first, in S310, it is determined whether or not the host vehicle is in a forward traveling state and the state of the direction indicator is ON.

  Whether or not the vehicle is in a forward state is determined based on vehicle speed and shift lever position information acquired via the in-vehicle network. Specifically, the vehicle speed has a positive value, or the shift lever It is determined that the vehicle is in the forward state when the position of is the position of the gear used for forward movement. The state of the direction indicator is also acquired via the in-vehicle network.

  In S320, based on the detection results in the previous S120 and S150, it is determined whether a vehicle (target) is detected in the rear approaching vehicle detection area. If detected, the process proceeds to S330 and the alarm is turned on. Then, the process returns to S310. Note that the alarm may be configured such that the sounding mode changes according to the detected distance to the target, the relative speed, and the azimuth angle.

  On the other hand, if the vehicle is not detected in the rear approaching vehicle detection area, the process proceeds to S340. If the alarm is ON, this is switched to OFF. If the alarm is OFF, do nothing. Return to S310.

Next, the crossing vehicle detection warning process at the time of reverse will be described along the flowchart shown in FIG.
When this process is started, first, in S410, it is determined whether or not the host vehicle is in a reverse state.

  Whether or not the vehicle is in the reverse state is determined based on vehicle speed and shift lever position information acquired via the in-vehicle network. Specifically, the vehicle speed has a negative value, or the shift lever Is determined to be in the reverse state.

  In S420, based on the detection results in the previous S130 and S160, it is determined whether or not a vehicle (target) is detected in the reverse crossing vehicle detection area, and if detected, the process proceeds to S430 and an alarm is issued. ON and return to S410. Note that the alarm may be configured such that the sounding mode changes according to the detected distance to the target, the relative speed, and the azimuth angle.

  On the other hand, if a vehicle is not detected in the crossing vehicle detection area when reversing, the process proceeds to S440, and if the alarm is ON, this is switched OFF, and if the alarm is OFF, nothing is done. Then, the process returns to S410.

<Effect>
As described above, in the radar apparatus 1, the planar radiation antenna unit 3 having the plane direction of the antenna substrate 6 as the main radiation direction, and the horizontal radiation antenna unit 4 having the end direction of the antenna substrate 6 as the main irradiation direction, However, since the antenna substrate 6 is formed in different pattern formation layers, the directivity of the horizontal radiation antenna portion 4 is flat compared with the case where both antenna portions 3 and 4 are formed in the same pattern formation layer. It can be directed in the back side direction with respect to the formation surface of the radiation antenna portion 3. As a result, the detection area that can be covered by the single antenna substrate 6 can be widened (for example, 180 ° or more).

[Second Embodiment]
Next, a second embodiment will be described.
In the present embodiment, since the contents of the system control processing executed by the radar device 1a serving as a master are only different from those in the first embodiment, this difference will be mainly described.

<System control processing>
FIG. 13 is a flowchart showing the contents of the system control process in this embodiment.
When this process is activated, first, in S510, it is determined whether or not the host vehicle is in a forward traveling state. Note that whether or not the vehicle is in the forward state is determined in the same manner as in S310.

If the host vehicle is moving forward, in S520, the master is operated in the blind spot vehicle detection mode and the slave is operated in the rear approaching vehicle detection mode.
In subsequent S530, contrary to S520, the master is operated in the backward approaching vehicle detection mode and the slave is operated in the blind spot vehicle detection mode, and then the process returns to S510.

  If it is determined in S510 that the host vehicle is not in the forward state, the process proceeds to S540, where it is determined whether or not the host vehicle is in the reverse state. If not, the process returns to S510. Whether or not the vehicle is in the reverse state is determined in the same manner as in S410.

  When it is determined in S540 that the host vehicle is in the reverse state, the master is operated in the blind spot vehicle detection mode and the slave is operated in the reverse crossing vehicle detection mode in S550.

In the subsequent S560, contrary to S550, the master is operated in the crossing vehicle detection mode during reverse movement, the slave is operated in the blind spot vehicle detection mode, and then the process returns to S510.
<Effect>
In the vehicle-mounted control system configured as described above, since the two radar devices (master and slave) 1a and 1b are simultaneously operated, the target detection can be performed efficiently.

  In addition, the detection modes of both radar apparatuses 1a and 1b are always combined so that the antenna unit to be used (and thus the detection area to be searched) and the radar wave method (pulse wave / continuous wave) used for the search are different. It is possible to prevent interference between the radar apparatuses 1a and 1b.

[Other Embodiments]
Although several embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist of the present invention. .

  In the above embodiment, the antenna board 6 having the horizontal radiation antenna portion 4 formed on the component placement surface 6b (outer layer) is used. However, as shown in FIG. The antenna substrate 7 formed on the pattern forming layer (inner layer) facing the mounting surface 7b with one insulating layer interposed therebetween may be used.

14A is a plan view of the antenna substrate 7 viewed from the component mounting surface 7b side, and FIG. 14B is a cross-sectional view of the antenna substrate 7. FIG.
As shown in FIG. 14, in the antenna substrate 7, the planar radiation antenna unit 3 is formed on the antenna forming surface 7 a similarly to the antenna substrate 6, and the ground pattern 71 and the horizontal radiation antenna unit for the planar radiation antenna unit 3 are formed. 4 is formed in a pattern forming layer (inner layer) that is opposed to the antenna units 3 and 4 to be fed with each other with a single insulating layer interposed therebetween. A ground pattern 73 for the feeder line 72 is formed on the inner layer located on the antenna formation surface side with one insulating layer interposed between the formed inner layer.

  In the above embodiment, tapered slot antennas are used as the horizontal radiating unit antennas SE and RE constituting the horizontal radiating antenna unit 4. However, as shown in FIG. 15, a dipole antenna formed by a pattern is used. Also good.

  15A is a plan view of the antenna substrate 8 viewed from the component mounting surface 8b side, FIG. 15B is a cross-sectional view of the antenna substrate 8, and FIG. 15C is a positional relationship between the feed line and the dipole antenna. It is explanatory drawing which shows.

  As shown in FIG. 15, the antenna radiation surface 3 is formed on the antenna formation surface 8a (outer layer) of the antenna substrate 8 in the same manner as the antenna substrate 6, and one insulating layer is formed on the antenna formation surface 8a. A ground pattern 81 for the planar radiating antenna unit 3 is formed on the pattern forming layer (inner layer) facing each other.

  On the other hand, on the component placement surface 8b of the antenna substrate 8, not only the horizontal radiation antenna portion 4 but also a feed line (microstrip line) 82 for the horizontal radiation antenna portion 4 is formed. On the other hand, a ground pattern 83 for the feed line 82 is formed on the pattern forming layer (inner layer) facing each other with one insulating layer interposed therebetween.

  And as shown in FIG.15 (c), the ground pattern 83 is abbreviate | omitted and the distance D of the edge part of the ground pattern 83 and the horizontal radiation antenna part 4 is the power feeding end side of the feeder 82. It is formed to have a length of about ¼ wavelength of electromagnetic waves to be transmitted and received.

  In the antenna substrate 8 on which the horizontal radiation antenna unit 4 and the feed line 82 are formed so as to have such a positional relationship with the distance D, the antenna gain can be improved and the main component of the horizontal radiation antenna unit 4 can be improved. The radiation direction (beam direction) can be shifted from the end direction to the component placement surface 8b side of the antenna substrate 8.

  In the above embodiment, a combination of operation modes of the plane radiation mode and the continuous wave mode, or the horizontal radiation mode and the pulse wave mode is used as the detection mode of the in-vehicle radar system, but the combination of the operation modes is limited to this. Instead, a combination of a plane radiation mode and a pulse wave mode, a horizontal radiation mode and a continuous wave mode may be used.

  DESCRIPTION OF SYMBOLS 1 ... Radar apparatus 1a ... Master (radar apparatus) 1b ... Slave (radar apparatus) 3 ... Planar radiation antenna part 4 ... Horizontal radiation antenna part 5 ... Control circuit 6, 7, 8 ... Antenna board 6a, 7a, 8a ... Antenna forming surface 6b, 7b, 8b ... Component placement surface 10 ... Transmitter 11 ... Voltage controlled oscillator (VCO) 2, 21, 25 ... Amplifier 13 ... Branch line 14 ... Pulse generator 15 ... Distributor 16 ... Signal control unit DESCRIPTION OF SYMBOLS 20 ... Receiver 21 ... Amplifier 22 ... Reception switch circuit 23 ... Pulse generator 24 ... Mixer 31 ... Planar radiation transmission antenna group 32 ... Planar radiation reception antenna group 41 ... Horizontal radiation transmission antenna 42 ... Horizontal radiation reception Antenna 61, 63, 71, 73, 81, 83 ... Ground pattern 62, 72, 82 ... Feed line

Claims (19)

A substrate having two or more pattern forming layers;
A plurality of plane emission elements formed on the outer layer, which is a pattern forming layer in which one surface is in contact with the insulating layer and the other surface is opened, and radiates electromagnetic waves toward the lamination direction of the pattern forming layer and is arranged in a row. A planar radiation antenna unit comprising unit antennas;
It is formed in a pattern forming layer different from the planar radiation antenna, and is disposed at at least one end of both ends of the antenna array direction which is the array direction of the planar radiation unit antennas. A horizontal radiating antenna unit comprising at least one horizontal radiating unit antenna that radiates electromagnetic waves toward the
An antenna device comprising:   The antenna apparatus according to claim 1, wherein the horizontal radiating antenna unit is formed in an outer layer different from the horizontal radiating antenna unit.   The antenna device according to claim 1, wherein the horizontal radiating antenna unit is formed in an inner layer which is a pattern forming layer having both surfaces facing an insulating layer.   Power feeding to the horizontal radiation antenna unit is performed from a pattern formation layer located between the pattern formation layer in which the horizontal radiation antenna unit is formed and the pattern formation layer in which the planar radiation antenna unit is formed. The antenna device according to claim 1, wherein the antenna device is configured as described above.   The planar radiation antenna unit includes a transmission-dedicated transmission antenna unit and a reception-dedicated reception antenna unit arranged along the antenna arrangement direction, and each of the planar radiation antenna units includes a plurality of planar radiation unit antennas. The antenna device according to any one of claims 1 to 4, wherein the antenna device is characterized.   The horizontal radiating antenna unit includes a transmission-dedicated transmission antenna unit and a reception-dedicated reception unit antenna unit arranged along a direction orthogonal to the antenna arrangement direction, each of which includes at least one horizontal radiating unit antenna. The antenna device according to claim 1, wherein the antenna device is configured as follows.   7. The planar antenna unit antenna includes a plurality of patch antennas arranged in one or a plurality of rows along a direction perpendicular to the antenna arrangement direction. The antenna device according to item.   The antenna device according to claim 1, wherein the horizontal radiating unit antenna includes a tapered slot antenna.   Electronic components constituting a transmitting unit and a receiving unit that transmit and receive electromagnetic waves via the planar radiation antenna unit and the horizontal radiation antenna unit are mounted on an outer layer different from the horizontal radiation antenna unit. The antenna device according to any one of claims 1 to 8. The antenna device according to any one of claims 1 to 9,
A transmitting unit that selects one of the planar radiating antenna unit and the horizontal radiating antenna unit constituting the antenna device and transmits electromagnetic waves;
A receiving unit that selects one of the planar radiation antenna unit and the horizontal radiation antenna unit constituting the antenna device and receives electromagnetic waves;
A signal processing unit that selects an antenna unit to be used for transmission and reception, transmits an electromagnetic wave through the transmission unit, and executes a process of detecting a target based on a signal acquired through the reception unit;
A radar apparatus comprising:   The transmitting unit controls the amplitude and phase of a transmission signal supplied to each of the planar radiation unit antennas used for transmitting electromagnetic waves, thereby changing the directivity of the electromagnetic waves transmitted by the planar radiation antenna unit. The radar apparatus according to claim 10, further comprising a phase control circuit. The reception unit individually supplies a reception signal from each of the planar radiation unit antennas used for reception of electromagnetic waves to the signal processing unit,
The radar apparatus according to claim 10 or 11, wherein the signal processing unit executes a process of estimating an arrival direction of an electromagnetic wave using phase information of each received signal.   When the transmission unit transmits an electromagnetic wave through the planar radiation antenna unit, the reception unit also receives the electromagnetic wave through the planar radiation antenna unit, and the transmission unit receives the horizontal radiation antenna. The transmission unit and the reception unit are controlled so that the reception unit also receives the electromagnetic wave through the horizontal radiation antenna unit when transmitting the electromagnetic wave through the unit. The radar apparatus according to any one of claims 10 to 12.   The transmitter and the receiver have a pulse wave mode that is an operation mode for transmitting and receiving a pulse wave and a continuous wave mode that is an operation mode for transmitting and receiving a continuous wave. The radar device according to any one of the above.   The transmission unit and the reception unit operate in a continuous wave mode when using the planar radiation antenna unit, and operate in a pulse wave mode when using the horizontal radiation antenna unit. The on-vehicle radar system according to claim 14. Two radar devices according to claim 15 are provided,
The detection area of the planar radiation antenna part is a first area, the detection area of the horizontal radiation antenna part is a second area,
Of the two radar devices, one of the first areas is located on the right rear side of the vehicle, the second area is located on the right side of the vehicle, the other is the first area on the left rear side of the vehicle, and the second area is on the left side of the vehicle. An in-vehicle radar system, which is installed in a vehicle so as to be located at   The first area is a rear approaching vehicle detection area set for detecting a vehicle approaching from the rear, or a reverse crossing vehicle detection area set for detecting a vehicle that is about to cross the rear of the vehicle when moving backward. The on-vehicle radar system according to claim 16, wherein   The in-vehicle radar system according to claim 16 or 17, wherein the second area is a blind spot vehicle detection area that is set to detect a vehicle existing at a position that is a blind spot of the driver.   The in-vehicle radar system according to any one of claims 16 to 18, further comprising a system control unit that operates the two radar devices simultaneously in different operation modes.