WO2020230694A1

WO2020230694A1 - Mobile body

Info

Publication number: WO2020230694A1
Application number: PCT/JP2020/018544
Authority: WO
Inventors: 吉澤　淳
Original assignee: ソニー株式会社
Priority date: 2019-05-16
Filing date: 2020-05-07
Publication date: 2020-11-19

Abstract

The present disclosure pertains to a mobile body in which it is possible to suppress reflection or refraction that occurs at an interface with a vehicle body when radar transmission waves are transmitted such that the transmission directions of the radar transmission waves intersect the central axis of the vehicle body in front of the vehicle. The mobile body is provided with two or more vertical polarization-type radar transmitters arranged such that the transmission directions of the radar transmission waves intersect. The portion of the vehicle body in front of the plurality of radar transmitters is composed of members not having a relative permeability of one. The present technology can be applied to mobile bodies.

Description

Mobile

The present disclosure relates to a mobile body, and more particularly to a mobile body capable of improving detection sensitivity by reducing reflection and refraction with respect to radar transmitted waves.

Technology related to autonomous driving is becoming widespread. Various sensing devices mounted on vehicles are indispensable for realizing this automatic driving.

In particular, in-vehicle radar is an important configuration as a sensing device that supports automatic driving due to its excellent environmental resistance in bad weather such as rainy weather and fog, or in environments where camera sensing is not good, such as tunnel entrances and exits. Expected as an element.

In addition to this, in recent years, the performance of in-vehicle radar has been improved, and by more actively utilizing the information acquired by the in-vehicle radar, for example, reduction of the blind spot of the camera, motion recognition by microdoppler information, and SLAM ( It is expected to be applied to technologies such as acquisition of detailed road information by Simultaneous Localization and Mapping).

In a radar device used for such a new motive, an object is detected by arranging the transmission range of the radar transmission wave in front of the vehicle in the traveling direction so as to intersect from the left and right. A method for improving the viewing angle of is proposed.

More specifically, for example, by a radar device arranged at the left and right front ends of the vehicle so that the transmission range of the radar transmission wave is set diagonally forward so as to face the vehicle body central axis in the traveling direction. A technique has been proposed in which the radar transmission wave of the radar device installed on the left side of the vehicle detects the front right side of the vehicle, and the radar transmission wave of the radar device installed on the right side of the vehicle detects the front left side of the vehicle ( See Patent Document 1).

By setting diagonally so that the transmission ranges of such radar transmission waves intersect, it is expected that the viewing angle in the diagonally forward direction will be improved.

However, when the radar transmitting device is arranged in an oblique direction so that the transmission ranges of the radar transmitting waves intersect as proposed in Patent Document 1, the body, bumper, or other vehicle body arranged in front of the radar device causes the radar transmission device to be arranged in an oblique direction. There is a concern that unintended deterioration may occur in the radar transmission wave.

That is, the radar transmission wave, which is an electromagnetic wave, is obliquely incident on the interface with the vehicle body such as a bumper or a vehicle body composed of a dielectric material, so that the radar transmission wave such as reflection or refraction is reflected or refracted at the interface. The undesired phenomenon may cause deterioration of the detection sensitivity of the radar device.

Therefore, by installing radar devices on the curved parts on both sides of the vehicle for signals radiated diagonally to the outside of the vehicle body such as the bumper and body, the radar transmission waves are reflected and refracted by the vehicle body such as the bumper and body. A technique for reducing the influence has been proposed (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2010-018244 Japanese Patent No. 4766402

However, the technique of Patent Document 2 is a solution when the transmission direction of the radar transmission wave is directed outward from the corner of the vehicle, and is toward the central axis of the vehicle with respect to the traveling direction from the left and right ends in front of the vehicle. It cannot be applied when the radar transmission wave is transmitted so that the transmission range intersects on the vehicle body center axis in front of the vehicle.

The present disclosure has been made in view of such a situation, and occurs at an interface with the vehicle body, particularly when the transmission direction of the radar transmission wave is transmitted so as to intersect on the vehicle body central axis in front of the vehicle. It makes it possible to suppress reflection and refraction, and improves the detection sensitivity of the radar device.

The moving body on one side of the present disclosure includes two or more vertically polarized radar transmission wave transmitters arranged so that the transmission directions of the radar transmission waves intersect with respect to the radar transmission wave transmitter. A part of the vehicle body placed in front is a moving body made of a member having a relative magnetic permeability of not 1.

In one aspect of the present disclosure, two or more vertically polarized radar transmission wave transmitters arranged so that the transmission directions of the respective radar transmission waves intersect are provided with respect to the radar transmission wave transmitter. , A part of the vehicle body placed in front is composed of a member whose relative magnetic permeability is not 1.

It is a figure explaining that the transmission range of the radar transmission wave by the radar apparatus for a plurality of distances is set. It is a figure explaining the setting example of the transmission range of the medium-range radar transmission wave. It is a block diagram explaining the difference in the expected angle when recognizing an object when different transmission ranges are set. It is a figure explaining the example that the transmission range of the radar transmission wave transmitted by the radar apparatus provided at the left and right front end intersects at the center position of a vehicle. It is a figure explaining the installation example of the radar apparatus which is the outline of this disclosure. It is a figure explaining another example of the installation example of the radar apparatus which is the outline of this disclosure. It is a figure explaining the structural example of the vehicle which is a moving body of this disclosure. It is a figure explaining the installation example of the radar apparatus of this disclosure. It is a figure explaining another example of the installation example of the radar apparatus of this disclosure. It is a circuit block diagram explaining the configuration example of a radar apparatus. It is a block diagram explaining the configuration example of a phase shifter. It is a figure explaining other configuration example of a power distributor. It is a figure explaining the structural example of the power distributor of FIG. It is a figure explaining the structural example of the signal processing unit. It is a figure explaining the configuration example of the array antenna as an element antenna. It is a figure explaining the configuration example of the array antenna including a plurality of element antennas. It is a figure explaining the example of the characteristic of the array antenna as a plurality of element antennas. It is a figure explaining the Brewster angle. It is a figure explaining the structural example of the member which has a relative permittivity not 1.

The preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings below. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

Hereinafter, modes for implementing the present technology will be described. The explanation will be given in the following order.
1. 1. Outline of the present disclosure 2. Suitable Embodiment

<< 1. Summary of the present disclosure >>
The present disclosure reduces reflections and refractions that occur at the interface with the vehicle body when the radar transmission waves are transmitted in front of the vehicle and intersect on the vehicle body central axis in a direction orthogonal to the vehicle traveling direction. It is a thing.

As a method of transmitting radar transmission waves in the forward direction in the traveling direction, it has been generally practiced to transmit a combination of a plurality of radar transmission waves having different characteristics according to the sensing distance.

For example, the left part of FIG. 1 shows an example in which three types of transmission waves, a short-range radar transmission wave, a medium-range radar transmission wave, and a long-range radar transmission wave, are used in combination. ..

In the left part of FIG. 1, the transmission range Z _SL , Z _SR , in which the short-range radar transmission wave is transmitted from the left and right in front of the vehicle C1, and the transmission range Z _ML , in which the medium-range radar transmission wave is transmitted, The Z _MR and the transmission range Z _{L at} which the long-range radar transmission wave is transmitted from the front center are set.

Further, for example, the right part of FIG. 1 shows an example in which two types of transmission waves, a medium-range radar transmission wave and a long-range radar transmission wave, are used in combination.

In the right part of FIG. 1, the transmission range Z _ML and Z _{MR in which} the medium-range radar transmission wave is transmitted from the left and right in front of the vehicle C2, and the transmission range ZL in which the long-range radar transmission wave is transmitted from the front center. Is set.

Normally, short-range radar transmission waves cover the widest field of view and are mainly used to sense the surrounding environment at short distances.

On the other hand, the long-range radar transmission wave is optimized to detect a distant target such as 100 to 300 m away, and normally, the radar device transmits the highest gain beam-like radar transmission wave.

In addition, a medium-range radar transmission wave may be adopted as a radar transmission wave having an intermediate performance between a short-range radar transmission wave and a long-range radar transmission wave.

The medium-range radar transmission wave is used, for example, to sense the situation several tens of meters away, and covers an intermediate distance and viewing angle.

In the present disclosure, a radar device that transmits a medium-range radar transmission wave or a radar transmission wave having performance equivalent to a short-range radar transmission wave is assumed.

Here, among the medium-range radar transmission wave and the radar transmission wave having the performance equivalent to the short-range radar transmission wave, for example, the radar device that transmits the medium-range radar transmission wave is located in front of the vehicle. When arranged at both ends, the transmission range of the radar transmission wave is assumed to have, for example, three types of configurations shown in the left portion, the center portion, and the right portion of FIG.

For example, as shown on the left side of FIG. 2, the central directions of the transmission ranges Z _ML1 and Z _MR1 are set to the front front so that the radar transmission wave is transmitted from the front ends of the vehicle C21 to the front front. The configuration is conceivable.

Further, as shown in the central portion of FIG. 2, the transmission is performed from both front end portions of the vehicle C21 toward the vehicle body center axis of the vehicle C21 in the direction perpendicular to the traveling direction, and is transmitted in the center directions of the transmission ranges Z _ML2 and Z _MR2 . Can be considered to be set so as to intersect on the central axis of the vehicle body.

Further, as shown in the right part of FIG. 2, the transmission range Z is such that the radar transmission wave is transmitted from the front end portions of the vehicle C21 to the outside from the vehicle body center axis of the vehicle C21 in the direction perpendicular to the traveling direction. _It is conceivable that the center direction of the _ML3 and Z _MR3 is set to the outside of the vehicle body.

However, in the case of the left part of FIG. 2, when the vehicle C21 is traveling in the traveling lane L1 of the road, the radar transmission wave transmitted to the vehicle C22 traveling in the oncoming lane L2 is only a part of the transmission range Z _MR1 . Therefore, it cannot be said that the transmission range is suitable for searching the vehicle C22.

Further, in the case of the central portion and the right portion of FIG. 2, the vehicle C22 in the oncoming lane L2 can be transmitted from almost the front at the substantially center positions of the transmission ranges Z _ML2 and Z _MR3 , respectively, and the vehicle C22 can be transmitted. It can be said that the transmission range is suitable for searching.

However, within the transmission range Z _ML2 , when the radar transmission wave is transmitted to the vehicle C22, the radar transmission wave is transmitted at the expected angle θ1 as shown in the left part of FIG.

On the other hand, when the radar transmission wave is transmitted to the vehicle C22 within the transmission range Z _MR3 , the radar transmission wave is transmitted at a viewing angle θ2 (<θ1) as shown in the right part of FIG. It will be.

As a result, in order to detect more feature points in the vehicle C22 by transmitting the radar transmission wave, the vehicle travels by the transmission range Z _ML2 having a prospect angle θ2 wider than the prospect angle θ1, that is, from both ends in front of the vehicle C21. It can be said that it is desirable to have a configuration in which the transmission range of the radar transmission wave is set in the front inner direction toward the vehicle center axis in the direction perpendicular to the direction.

Here, as shown in FIG. 4, radar devices RL and RR are provided at the left and right ends in front of the vehicle C51, and the center line of the transmission range of the radar transmission wave transmitted from the left and right radar devices RL and RR is set. Consider a case where radar devices RL and RR are provided so as to intersect on the vehicle center axis represented by the alternate long and short dash line in the figure in front of the vehicle C51, which is the upper part in the figure.

That is, as shown in FIG. 4, the radar device RL is arranged at the front left end and is arranged so that the center line of the transmission range of the radar transmission wave faces to the right.

Further, the radar device RR is arranged at the front right end, and is arranged so that the center line of the transmission range of the radar transmission wave faces to the left.

When the left and right radar devices RL and RR are arranged in this way, the transmission ranges of the radar transmission waves of each other are configured to intersect in the space in front of the vehicle C51.

At this time, in the medium-range and short-range ranges, the transmission range of the radar transmission wave can be widened by increasing the viewing angle θ11 in the transmission range of the radar transmission wave of the radar devices RL and RR.

However, in the case of FIG. 4, when the viewing angle θ11 of the radar transmission wave transmitted by each radar device RL, RR becomes large, the radar transmission wave of the vehicle body (or bumper) B or the like in front of the radar devices RL, RR. The difference between the angles of view θ31 and θ32 incident on the vehicle body B at both ends of the transmission range of the radar transmission wave is significantly different.

That is, since the difference between the incident angles θ31 and θ32 in the figure becomes large, the reflection and refraction of the radar transmitted wave in the vehicle body (or bumper) B vary greatly, and the performance of the radar devices RL and RR deteriorates. ..

Therefore, in the present disclosure, as shown in FIG. 5, instead of the radar devices RL and RR, radar devices ARL1 and ARR1 provided with a plurality of phase shifters and an array antenna are provided, and further, the vehicle body is further provided. A member FL having a relative magnetic permeability of not 1 is arranged in a part of (or bumper) B.

By using the radar devices ARL1 and ARR1 equipped with an array antenna, the viewing angle θ of the transmission range is narrowed by beamforming the radar transmission wave, and the radar transmission wave passing through the vehicle body (or bumper) B is reduced.

By reducing the viewing angle θ of the transmission range of the radar transmission wave passing through the vehicle body (or bumper) B in this way, the influence of undesired characteristic variation due to the reflection and refraction of the radar transmission wave at the interface with the vehicle body B is affected. Reduce.

In addition, the radar devices ARL1 and ARR1 equipped with a phase shifter and an array antenna make the transmission range of the radar transmission wave variable, and selectively transmit the radar transmission wave in the forward and diagonal directions to transmit the optimum radar transmission wave. Realize.

That is, as shown in FIG. 5, radar devices ARL and ARR equipped with a phase shifter and an array antenna are provided so as to face the vehicle body B, and the beamforming of the radar transmission wave is performed in the front direction of the vehicle body B. The transmission ranges Z _MRC and Z _MLC are formed with respect to the vehicle body B, and the transmission ranges Z _MRS and Z _MLS are formed with respect to the diagonal direction of the vehicle body B.

Here, since the transmission ranges Z _MRC and Z _MLC formed with respect to the front direction of the vehicle body B are the optimum points as the transmission direction of the radar transmission wave, the deterioration of the characteristics can be reduced.

In addition, the phase shifters and array antennas of the radar devices ARL1 and ARR1 set the optimum points for the transmission ranges Z _MRS and Z _MLS formed by beamforming in the oblique direction of the vehicle body B, and the vehicle body. A member FL having a relative magnetic permeability of not 1 is provided in a part of the range overlapping the transmission ranges Z _MRS and Z _MLS in B. As a result, the variation due to reflection and refraction generated at the interface with the vehicle body B due to the radar transmission wave is reduced, so that the deterioration of the characteristics can be reduced.

As a result, it is possible to reduce the variation due to reflection and refraction in the vehicle body B while increasing the horizontal viewing angle of the radar device, and it is possible to reduce the deterioration of the characteristics.

Further, as shown in FIG. 6, the radar devices ARL2 and ARR2 having the radar devices ARL1 and ARR1 provided with the array antenna facing the central axis of the vehicle C71 are provided so as to provide the optimum points with respect to the facing direction. By transmitting radar transmission waves to the transmission range Z _MRC and Z _MLC in which is set, it may be used for searching for objects on the left and right sides.

At this time, the front direction of the vehicle C71 is set so that the optimum point is set in the transmission ranges Z _MRS and Z _MLS formed in the oblique direction of the vehicle body B by the phase shifter and the array antenna of the radar devices ARL2 and ARR2. Used to search for objects in.

Transmission range Z A member FL whose relative permeability is not 1 is provided in a part of the vehicle body B that overlaps with Z _MRS and Z _MLS, and the variation due to reflection and refraction due to radar transmission waves is small, so the deterioration of characteristics is reduced. be able to.

<< 2. Preferable Embodiment >>
FIG. 7 is a block diagram showing a configuration example of a schematic function of the vehicle control system 100 in the vehicle 91, which is an example of a mobile control system to which the present technology can be applied.

Hereinafter, when a vehicle provided with the vehicle control system 100 is distinguished from other vehicles, it is referred to as a own vehicle or a own vehicle.

The vehicle control system 100 includes an input unit 101, a data acquisition unit 102, a communication unit 103, an in-vehicle device 104, an output control unit 105, an output unit 106, a drive system control unit 107, a drive system system 108, a body system control unit 109, and a body. It includes a system system 110, a storage unit 111, and an automatic operation control unit 112. The input unit 101, the data acquisition unit 102, the communication unit 103, the output control unit 105, the drive system control unit 107, the body system control unit 109, the storage unit 111, and the automatic operation control unit 112 are connected via the communication network 121. They are interconnected. The communication network 121 is, for example, from an in-vehicle communication network or bus that conforms to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), or FlexRay (registered trademark). Become. In addition, each part of the vehicle control system 100 may be directly connected without going through the communication network 121.

In the following, when each part of the vehicle control system 100 communicates via the communication network 121, the description of the communication network 121 shall be omitted. For example, when the input unit 101 and the automatic operation control unit 112 communicate with each other via the communication network 121, it is described that the input unit 101 and the automatic operation control unit 112 simply communicate with each other.

The input unit 101 includes a device used by the passenger to input various data, instructions, and the like. For example, the input unit 101 includes an operation device such as a touch panel, a button, a microphone, a switch, and a lever, and an operation device capable of inputting by a method other than manual operation by voice or gesture. Further, for example, the input unit 101 may be a remote control device using infrared rays or other radio waves, or an externally connected device such as a mobile device or a wearable device corresponding to the operation of the vehicle control system 100. The input unit 101 generates an input signal based on data, instructions, and the like input by the passenger, and supplies the input signal to each unit of the vehicle control system 100.

The data acquisition unit 102 includes various sensors and the like that acquire data used for processing of the vehicle control system 100, and supplies the acquired data to each unit of the vehicle control system 100.

For example, the data acquisition unit 102 includes various sensors for detecting the state of the own vehicle and the like. Specifically, for example, the data acquisition unit 102 includes a gyro sensor, an acceleration sensor, an inertial measurement unit (IMU), an accelerator pedal operation amount, a brake pedal operation amount, a steering wheel steering angle, and an engine speed. It is equipped with a sensor or the like for detecting the rotation speed of the motor or the rotation speed of the wheels.

Further, for example, the data acquisition unit 102 includes various sensors for detecting information outside the own vehicle. Specifically, for example, the data acquisition unit 102 includes an imaging device such as a ToF (TimeOfFlight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. Further, for example, the data acquisition unit 102 includes an environment sensor for detecting the weather or the weather, and a surrounding information detection sensor for detecting an object around the own vehicle. The environment sensor includes, for example, a raindrop sensor, a fog sensor, a sunshine sensor, a snow sensor, and the like. The ambient information detection sensor includes, for example, an ultrasonic sensor, a radar, LiDAR (Light Detection and Ringing, Laser Imaging Detection and Ringing), a sonar, and the like. As an example of the ambient information detection sensor, a radar device 201 corresponding to the radar devices ARL1, ARL2, ARR1, ARR2 provided with the array antennas in FIGS. 5 and 6 is provided.

Further, for example, the data acquisition unit 102 includes various sensors for detecting the current position of the own vehicle. Specifically, for example, the data acquisition unit 102 includes a GNSS receiver or the like that receives a GNSS signal from a GNSS (Global Navigation Satellite System) satellite.

Further, for example, the data acquisition unit 102 includes various sensors for detecting information in the vehicle. Specifically, for example, the data acquisition unit 102 includes an imaging device that images the driver, a biosensor that detects the driver's biological information, a microphone that collects sound in the vehicle interior, and the like. The biosensor is provided on, for example, the seat surface or the steering wheel, and detects the biometric information of the passenger sitting on the seat or the driver holding the steering wheel.

The communication unit 103 communicates with the in-vehicle device 104 and various devices, servers, base stations, etc. outside the vehicle, transmits data supplied from each unit of the vehicle control system 100, and transmits the received data to the vehicle control system. It is supplied to each part of 100. The communication protocol supported by the communication unit 103 is not particularly limited, and the communication unit 103 may support a plurality of types of communication protocols.

For example, the communication unit 103 wirelessly communicates with the in-vehicle device 104 by wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), WUSB (Wireless USB), or the like. Further, for example, the communication unit 103 uses USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface) (registered trademark), or MHL (registered trademark) via a connection terminal (and a cable if necessary) (not shown). Wired communication is performed with the in-vehicle device 104 by Mobile High-definition Link) or the like.

Further, for example, the communication unit 103 is connected to a device (for example, an application server or a control server) existing on an external network (for example, the Internet, a cloud network or a network unique to a business operator) via a base station or an access point. Communicate. Further, for example, the communication unit 103 uses P2P (Peer To Peer) technology to connect with a terminal (for example, a pedestrian or store terminal, or an MTC (Machine Type Communication) terminal) existing in the vicinity of the own vehicle. Communicate. Further, for example, the communication unit 103 includes vehicle-to-vehicle (Vehicle to Vehicle) communication, road-to-vehicle (Vehicle to Infrastructure) communication, vehicle-to-house (Vehicle to Home) communication, and pedestrian-to-vehicle (Vehicle to Pedestrian) communication. ) Perform V2X communication such as communication. Further, for example, the communication unit 103 is provided with a beacon receiving unit, receives radio waves or electromagnetic waves transmitted from a radio station or the like installed on the road, and acquires information such as the current position, traffic congestion, traffic regulation, or required time. To do.

The in-vehicle device 104 includes, for example, a mobile device or a wearable device owned by a passenger, an information device carried in or attached to the own vehicle, a navigation device for searching a route to an arbitrary destination, and the like.

The output control unit 105 controls the output of various information to the passengers of the own vehicle or the outside of the vehicle. For example, the output control unit 105 generates an output signal including at least one of visual information (for example, image data) and auditory information (for example, audio data) and supplies it to the output unit 106 to supply the output unit 105. Controls the output of visual and auditory information from 106. Specifically, for example, the output control unit 105 synthesizes image data captured by different imaging devices of the data acquisition unit 102 to generate a bird's-eye view image, a panoramic image, or the like, and outputs an output signal including the generated image. It is supplied to the output unit 106. Further, for example, the output control unit 105 generates voice data including a warning sound or a warning message for dangers such as collision, contact, and entry into a danger zone, and outputs an output signal including the generated voice data to the output unit 106. Supply.

The output unit 106 is provided with a device capable of outputting visual information or auditory information to the passengers of the own vehicle or the outside of the vehicle. For example, the output unit 106 includes a display device, an instrument panel, an audio speaker, headphones, a wearable device such as a spectacle-type display worn by a passenger, a projector, a lamp, and the like. The display device included in the output unit 106 displays visual information in the driver's field of view, such as a head-up display, a transmissive display, and a device having an AR (Augmented Reality) display function, in addition to the device having a normal display. It may be a display device.

The drive system control unit 107 controls the drive system system 108 by generating various control signals and supplying them to the drive system system 108. Further, the drive system control unit 107 supplies a control signal to each unit other than the drive system system 108 as necessary, and notifies the control state of the drive system system 108.

The drive system system 108 includes various devices related to the drive system of the own vehicle. For example, the drive system system 108 includes a drive force generator for generating a drive force of an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle, and the like. It is equipped with a braking device that generates braking force, ABS (Antilock Brake System), ESC (Electronic Stability Control), an electric power steering device, and the like.

The body system control unit 109 controls the body system 110 by generating various control signals and supplying them to the body system 110. Further, the body system control unit 109 supplies control signals to each unit other than the body system 110 as necessary, and notifies the control state of the body system 110.

The body system 110 includes various body devices equipped on the vehicle body. For example, the body system 110 includes a keyless entry system, a smart key system, a power window device, a power seat, a steering wheel, an air conditioner, and various lamps (for example, head lamps, back lamps, brake lamps, winkers, fog lamps, etc.). Etc.

The storage unit 111 includes, for example, a magnetic storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, an optical magnetic storage device, and the like. .. The storage unit 111 stores various programs, data, and the like used by each unit of the vehicle control system 100. For example, the storage unit 111 contains map data such as a three-dimensional high-precision map such as a dynamic map, a global map which is less accurate than the high-precision map and covers a wide area, and a local map including information around the own vehicle. Remember.

The automatic driving control unit 112 controls automatic driving such as autonomous driving or driving support. Specifically, for example, the automatic driving control unit 112 issues collision avoidance or impact mitigation of the own vehicle, follow-up running based on the inter-vehicle distance, vehicle speed maintenance running, collision warning of the own vehicle, lane deviation warning of the own vehicle, and the like. Collision control is performed for the purpose of realizing the functions of ADAS (Advanced Driver Assistance System) including. Further, for example, the automatic driving control unit 112 performs coordinated control for the purpose of automatic driving in which the vehicle autonomously travels without depending on the operation of the driver. The automatic operation control unit 112 includes a detection unit 131, a self-position estimation unit 132, a situation analysis unit 133, a planning unit 134, and an operation control unit 135.

The detection unit 131 detects various types of information necessary for controlling automatic operation. The detection unit 131 includes an outside information detection unit 141, an inside information detection unit 142, and a vehicle state detection unit 143.

The vehicle outside information detection unit 141 performs detection processing of information outside the own vehicle based on data or signals from each unit of the vehicle control system 100. For example, the vehicle outside information detection unit 141 performs detection processing, recognition processing, tracking processing, and distance detection processing for an object around the own vehicle. Objects to be detected include, for example, vehicles, people, obstacles, structures, roads, traffic lights, traffic signs, road markings, and the like. Further, for example, the vehicle outside information detection unit 141 performs detection processing of the environment around the own vehicle. The surrounding environment to be detected includes, for example, weather, temperature, humidity, brightness, road surface condition, and the like. The vehicle outside information detection unit 141 outputs data indicating the result of the detection process to the self-position estimation unit 132, the map analysis unit 151 of the situation analysis unit 133, the traffic rule recognition unit 152, the situation recognition unit 153, and the operation control unit 135. It is supplied to the emergency situation avoidance unit 171 and the like.

The in-vehicle information detection unit 142 performs in-vehicle information detection processing based on data or signals from each unit of the vehicle control system 100. For example, the vehicle interior information detection unit 142 performs driver authentication processing and recognition processing, driver status detection processing, passenger detection processing, vehicle interior environment detection processing, and the like. The state of the driver to be detected includes, for example, physical condition, alertness, concentration, fatigue, gaze direction, and the like. The environment inside the vehicle to be detected includes, for example, temperature, humidity, brightness, odor, and the like. The vehicle interior information detection unit 142 supplies data indicating the result of the detection process to the situational awareness unit 153 of the situational analysis unit 133, the emergency situation avoidance unit 171 of the motion control unit 135, and the like.

The vehicle state detection unit 143 performs the state detection process of the own vehicle based on the data or signals from each part of the vehicle control system 100. The states of the own vehicle to be detected include, for example, speed, acceleration, steering angle, presence / absence and content of abnormality, driving operation state, power seat position / tilt, door lock state, and other in-vehicle devices. The state etc. are included. The vehicle state detection unit 143 supplies data indicating the result of the detection process to the situation recognition unit 153 of the situation analysis unit 133, the emergency situation avoidance unit 171 of the operation control unit 135, and the like.

The self-position estimation unit 132 estimates the position and attitude of the own vehicle based on data or signals from each unit of the vehicle control system 100 such as the vehicle exterior information detection unit 141 and the situation recognition unit 153 of the situation analysis unit 133. Perform processing. In addition, the self-position estimation unit 132 generates a local map (hereinafter, referred to as a self-position estimation map) used for self-position estimation, if necessary. The map for self-position estimation is, for example, a highly accurate map using a technique such as SLAM (Simultaneous Localization and Mapping). The self-position estimation unit 132 supplies data indicating the result of the estimation process to the map analysis unit 151, the traffic rule recognition unit 152, the situation recognition unit 153, and the like of the situation analysis unit 133. Further, the self-position estimation unit 132 stores the self-position estimation map in the storage unit 111.

The situation analysis unit 133 analyzes the situation of the own vehicle and the surroundings. The situation analysis unit 133 includes a map analysis unit 151, a traffic rule recognition unit 152, a situation recognition unit 153, and a situation prediction unit 154.

The map analysis unit 151 uses data or signals from each unit of the vehicle control system 100 such as the self-position estimation unit 132 and the vehicle exterior information detection unit 141 as necessary, and the map analysis unit 151 of various maps stored in the storage unit 111. Perform analysis processing and build a map containing information necessary for automatic driving processing. The map analysis unit 151 applies the constructed map to the traffic rule recognition unit 152, the situation recognition unit 153, the situation prediction unit 154, the route planning unit 161 of the planning unit 134, the action planning unit 162, the operation planning unit 163, and the like. Supply to.

The traffic rule recognition unit 152 determines the traffic rules around the own vehicle based on data or signals from each unit of the vehicle control system 100 such as the self-position estimation unit 132, the vehicle outside information detection unit 141, and the map analysis unit 151. Perform recognition processing. By this recognition process, for example, the position and state of the signal around the own vehicle, the content of the traffic regulation around the own vehicle, the lane in which the vehicle can travel, and the like are recognized. The traffic rule recognition unit 152 supplies data indicating the result of the recognition process to the situation prediction unit 154 and the like.

The situation recognition unit 153 can be used for data or signals from each unit of the vehicle control system 100 such as the self-position estimation unit 132, the vehicle exterior information detection unit 141, the vehicle interior information detection unit 142, the vehicle condition detection unit 143, and the map analysis unit 151. Based on this, the situation recognition process related to the own vehicle is performed. For example, the situational awareness unit 153 performs recognition processing such as the situation of the own vehicle, the situation around the own vehicle, and the situation of the driver of the own vehicle. In addition, the situational awareness unit 153 generates a local map (hereinafter, referred to as a situational awareness map) used for recognizing the situation around the own vehicle, if necessary. The situational awareness map is, for example, an occupied grid map (OccupancyGridMap).

The status of the own vehicle to be recognized includes, for example, the position, posture, movement (for example, speed, acceleration, moving direction, etc.) of the own vehicle, and the presence / absence and contents of an abnormality. The surrounding conditions of the vehicle to be recognized include, for example, the type and position of surrounding stationary objects, the type, position and movement of surrounding animals (for example, speed, acceleration, moving direction, etc.), and the surrounding roads. The composition and road surface condition, as well as the surrounding weather, temperature, humidity, brightness, etc. are included. The state of the driver to be recognized includes, for example, physical condition, arousal level, concentration level, fatigue level, eye movement, driving operation, and the like.

The situational awareness unit 153 supplies data indicating the result of the recognition process (including a situational awareness map, if necessary) to the self-position estimation unit 132, the situation prediction unit 154, and the like. Further, the situational awareness unit 153 stores the situational awareness map in the storage unit 111.

The situation prediction unit 154 performs a situation prediction process related to the own vehicle based on data or signals from each part of the vehicle control system 100 such as the map analysis unit 151, the traffic rule recognition unit 152, and the situation recognition unit 153. For example, the situation prediction unit 154 performs prediction processing such as the situation of the own vehicle, the situation around the own vehicle, and the situation of the driver.

The situation of the own vehicle to be predicted includes, for example, the behavior of the own vehicle, the occurrence of an abnormality, the mileage, and the like. The situation around the own vehicle to be predicted includes, for example, the behavior of the animal body around the own vehicle, the change in the signal state, the change in the environment such as the weather, and the like. The driver's situation to be predicted includes, for example, the driver's behavior and physical condition.

The situation prediction unit 154, together with the data from the traffic rule recognition unit 152 and the situation recognition unit 153, provides the data indicating the result of the prediction processing to the route planning unit 161, the action planning unit 162, and the operation planning unit 163 of the planning unit 134. And so on.

The route planning unit 161 plans a route to the destination based on data or signals from each unit of the vehicle control system 100 such as the map analysis unit 151 and the situation prediction unit 154. For example, the route planning unit 161 sets a route from the current position to the specified destination based on the global map. Further, for example, the route planning unit 161 appropriately changes the route based on the conditions of traffic congestion, accidents, traffic restrictions, construction, etc., and the physical condition of the driver. The route planning unit 161 supplies data indicating the planned route to the action planning unit 162 and the like.

The action planning unit 162 safely routes the route planned by the route planning unit 161 within the planned time based on the data or signals from each unit of the vehicle control system 100 such as the map analysis unit 151 and the situation prediction unit 154. Plan your vehicle's actions to drive. For example, the action planning unit 162 plans starting, stopping, traveling direction (for example, forward, backward, left turn, right turn, change of direction, etc.), traveling lane, traveling speed, and overtaking. The action planning unit 162 supplies data indicating the planned behavior of the own vehicle to the motion planning unit 163 and the like.

The motion planning unit 163 is the operation of the own vehicle for realizing the action planned by the action planning unit 162 based on the data or signals from each unit of the vehicle control system 100 such as the map analysis unit 151 and the situation prediction unit 154. Plan. For example, the motion planning unit 163 plans acceleration, deceleration, traveling track, and the like. The motion planning unit 163 supplies data indicating the planned operation of the own vehicle to the acceleration / deceleration control unit 172 and the direction control unit 173 of the motion control unit 135.

The motion control unit 135 controls the motion of the own vehicle. The operation control unit 135 includes an emergency situation avoidance unit 171, an acceleration / deceleration control unit 172, and a direction control unit 173.

Based on the detection results of the outside information detection unit 141, the inside information detection unit 142, and the vehicle condition detection unit 143, the emergency situation avoidance unit 171 may collide, contact, enter a danger zone, have a driver abnormality, or cause a vehicle. Performs emergency detection processing such as abnormalities. When the emergency situation avoidance unit 171 detects the occurrence of an emergency situation, it plans the operation of the own vehicle to avoid an emergency situation such as a sudden stop or a sharp turn. The emergency situation avoidance unit 171 supplies data indicating the planned operation of the own vehicle to the acceleration / deceleration control unit 172, the direction control unit 173, and the like.

The acceleration / deceleration control unit 172 performs acceleration / deceleration control for realizing the operation of the own vehicle planned by the motion planning unit 163 or the emergency situation avoidance unit 171. For example, the acceleration / deceleration control unit 172 calculates a control target value of a driving force generator or a braking device for realizing a planned acceleration, deceleration, or sudden stop, and drives a control command indicating the calculated control target value. It is supplied to the system control unit 107.

The direction control unit 173 performs direction control for realizing the operation of the own vehicle planned by the motion planning unit 163 or the emergency situation avoidance unit 171. For example, the direction control unit 173 calculates the control target value of the steering mechanism for realizing the traveling track or the sharp turn planned by the motion planning unit 163 or the emergency situation avoidance unit 171 and controls to indicate the calculated control target value. The command is supplied to the drive system control unit 107.

<Installation example of radar device>
Next, an installation example of the radar device 201 will be described.

As shown in FIG. 8, the radar device 201 is provided at the front left and right ends of the vehicle 91. In FIG. 8, the radar device 201 provided at the left end portion in front of the vehicle 91 is referred to as a radar device 201L, and the radar device 201 provided at the right end portion in front of the vehicle 91 is referred to as a radar device 201R.

In the following, when it is not necessary to distinguish the

radar devices

201L and 201R, the

radar devices

201L and 201R shall be simply referred to as the radar device 201, and other configurations shall be the same.

Further, the radar device 201 is configured to include a phase shifter and an array antenna in combination, and adjusts the transmission direction (irradiation direction) and width (viewing angle) by adjusting the amount of phase change by the phase shifter. Then, the radar transmission wave is transmitted (irradiated).

In FIG. 8, as the transmission range of the radar transmission wave of the

radar devices

201L and 201R, the transmission range Z in the front front direction of the vehicle, in which the central direction of the transmission range faces the surfaces 201fL and 201fR formed by the array antenna. _{The MLC} and Z _MRC and the transmission ranges Z _MLS and Z _MRS that intersect on the central axis of the vehicle 91 indicated by the alternate long and _short dash line are set, respectively.

Generally, in the radar device 201 provided with the array antenna, the direction facing the surface formed by the array antenna is the optimum point of the detection accuracy of the radar device 201.

Therefore, in the

radar devices

201L and 201R of FIG. 8, the transmission ranges Z _MLC and Z _MRC are set to the optimum points of detection accuracy.

Further, in the vehicle body 91a which is the body and bumper portion of the vehicle 91, the range overlapping the transmission ranges Z _MLS and Z _MRS is composed of

members

221L and 221R having a relative magnetic permeability of not 1.

As described above, in the range overlapping with the transmission ranges Z _MLS and Z _MRS in the vehicle body 91a which is the body and bumper portion of the vehicle 91, the transmission range Z is formed by configuring the

members

221L and 221R whose relative magnetic permeability is not 1. It is possible to transmit radar transmission waves in _MLS and Z _MRS with high efficiency.

That is, it is assumed that the members generally used for the vehicle body 91a, which is the body and bumper portion of the vehicle 91, are made of a dielectric material such as polypropylene, and the dielectric constant is about 2.2 to 2.6. The radar transmission wave is reflected or refracted according to the incident angle.

For this reason, in particular, the radar transmission waves of the transmission ranges Z _MLS and Z _MRS in FIG. 8 have a large incident angle with respect to the vehicle body 91a, so that the vehicle body 91a made of a general dielectric material exists. Then, since the radar transmission wave is reflected or refracted, it is not transmitted forward from the vehicle body 91a, and there is a possibility that sufficient detection accuracy as the radar device 201 cannot be obtained.

Therefore, the range of the vehicle body 91a that overlaps with the transmission ranges Z _MLS and Z _MRS is composed of the

members

221L and 221R having a relative magnetic permeability of not 1, so that the radar transmission wave from the radar device 201 can be transmitted to the vehicle 91. It is configured so that it can be transmitted forward.

With such a configuration, even if the radar transmission waves of the transmission ranges Z _MLS and Z _MRS in FIG. 8 are incident on the vehicle 91 at an incident angle larger than a predetermined angle of incidence, they pass through the vehicle body 91a and the vehicle. Since it is transmitted in front of 91, it is possible to obtain sufficient detection accuracy.

The principle of the

members

221L and 221R having a relative magnetic permeability of not 1 transmitting the radar transmission wave from the radar device 201 will be described in detail later.

Further, regarding the radar transmission waves of the transmission ranges Z _MLC and Z _MRC in FIG. 8, since the reflection or refraction is small because the incident angle with respect to the vehicle body 91a is close to about 0 degrees, the vehicle body 91a is transparent. Even if it is not composed of

members

221L and 221R having a magnetic coefficient other than 1, and is composed of a dielectric material such as polypropylene, it can pass through the vehicle body 91a, so that sufficient detection accuracy can be ensured. It is possible.

Further, in the above, as shown in FIG. 8, an example has been described in which the surfaces 201fL and 201fR formed by the array antennas of the

radar devices

201L and 201R face the front direction of the front of the vehicle.

However, for example, as shown in FIG. 9, the surfaces 201fL'and 201fR'formed by the array antenna are configured to be directed toward the center of the vehicle 91 indicated by the alternate long and short dash line, and the vehicle is indicated by the alternate long and short dash line. Radar devices 201L', 201R'may be provided in place of the

radar devices

201L, 201R so that the central direction of 91 is covered by the transmission ranges Z _MLC and Z _MRC .

In the case of FIG. 9, the radar transmission from the radar device 201 is made so that the transmission range Z _MLC and Z _MRC in the vehicle body 91a are composed of the members 221L'and 221R' whose relative magnetic permeability is not 1. It is possible to transmit waves in front of the vehicle 91.

Further, in the case of FIG. 9, the transmission ranges Z _MLS and Z _MRS are formed in the front front direction of the vehicle 91 by adjusting the phase shifter by the combination of the phase shifter provided in the radar device 201 and the array antenna. Will be done.

Further, with respect to the radar transmission waves of the transmission ranges Z _MLS and Z _MRS in FIG. 9, since the reflection or refraction is small because the incident angle with respect to the vehicle body 91a is close to about 0 degrees, the vehicle body 91a is transparent. It is not composed of

members

221L and 221R having a magnetic coefficient of not 1, and even if it is composed of a dielectric material such as polypropylene, it can pass through the vehicle body 91a, so that sufficient detection accuracy can be ensured. It is possible.

In the present embodiment, the radar device 201 will be described as a configuration example provided at two locations on the left and right, but if the radar transmission waves are provided so as to overlap the transmission ranges, the radar device 201 will be described. The number of radar devices 201 may be provided.

<Circuit configuration example of radar device>
Next, a circuit configuration example of the radar device 201 will be described with reference to FIG.

The radar device 201 is composed of a transmission unit 231, a reception unit 232, a calibration data generation unit 233, a calibration data storage unit 234, a phase control unit 235, and a chirp signal generation unit 236.

The transmission unit 231 generates a radar transmission wave based on the chirp signal generated by the chirp signal generation unit 236, and transmits the transmission ranges Z _MLC , Z _MRC , and Z _MLS described with reference to FIGS. 8 and 9. , Z Send to _MRS .

More specifically, the transmission unit 231 is composed of an amplification unit 241, a power distributor 242, phase shifters 243-1 to 243-n, and an array antenna 244.

The array antenna 244 is composed of element antennas 244-1 to 244-n.

The amplification unit 241 amplifies the chirp signal generated by the chirp signal generation unit 236 and outputs it to the power distributor 242.

The power distributor 242 distributes chirp signals by the number corresponding to the plurality of element antennas 244a-1 to 244an and outputs them to the phase shifters 243-1 to 243-n, respectively.

The phase shifters 243-1 to 243-n are controlled by the phase control unit 235, control the phase of the radar transmission wave output from the element antennas 244a-1 to 244an, respectively, and transmit the radar from the array antenna 244. Send waves.

The phase shifter 243 may be realized by an individual phase shift circuit provided independently for each array antenna, but in order to realize an inexpensive and compact radar, the phase shifter is realized as an integrated circuit. Is desirable.

For example, “A High-Linearity 76-85-GHz 16-Element 8-Transmit / 8-Receive Phased-Array Chip With High Isolation and Flip-Chip Packaging,” IEEE Transaction on Microwave Theory and Techniques, vol. 62, no. 10, Oct. 2014 discloses an example of a phase shifter integrated by a semiconductor circuit.

FIG. 11 shows a configuration example of the integrated phase shifter 243. For a detailed description of the configuration, refer to “A High-Linearity 76-85-GHz 16-Element 8-Transmit / 8- See Receive Phased-Array Chip With High Isolation and Flip-Chip Packaging, ”IEEE Transaction on Microwave Theory and Techniques, vol. 62, no. 10, Oct. 2014.

It is desirable that the phase shifter 243 can usually change the phase by 360 ° and can rotate the input signal to an arbitrary phase.

The phase control unit 235 uses the calibration data stored in the calibration data storage unit 234 to adjust the amount of phase change by the phase shifters 243-1 to 243-n, whereby the element antennas 244a-1 to It is possible to adjust the phase of the radar transmission wave output from 244an and set the transmission direction of the radar transmission wave transmitted from the array antenna 244.

That is, by adjusting the amount of phase change by the phase control unit 235, for example, the transmission ranges Z _MLC , Z _MRC , and Z _MLS , Z _MRS of the radar transmission wave transmitted from the surfaces 201fL, 201fR formed by the array antenna 244 are set. Set.

Further, the power distributor 242 may have a configuration other than that shown in FIG. 10, and distributes the power distributor 242 to the four element antennas 244a-1 to 244a-4, for example, as shown in FIG. In this case, the power distributors 242'-1 to 242'-3, which distribute 1: 2, may be used to distribute the power in two stages, and the phase shifters 243-1 to 243-4 may be used for output.

The power distributor 242'in FIG. 12 may be composed of a distributor known as a so-called Wilkinson distributor, for example, as shown in FIG.

That is, in FIG. 13, the signals input by ports P1-1 and P1-2 are distributed to ports P2-1 to P2-2 and ports P3-1 to P3-2.

The details of the configuration of the element antenna 244a will be described later.

Return to the explanation of FIG.

The receiving unit 232 receives the reflected wave reflected by the object from the radar transmission wave transmitted from the transmitting unit 231 and determines the distance to the object, the speed of the object, and the direction of the object based on the received reflected wave. Detect and output the detection result.

More specifically, the receiving unit 232 includes receiving antennas 251-1 to 251-n, amplification units 252-1 to 252-n, synthesis units 253-1 to 253-n, and amplification units 254-1 to 254-n. It is composed of AD converters 255-1 to 255-n and a signal processing unit 256.

The receiving antennas 251-1 to 251-n receive the reflected wave whose radar transmission wave is reflected by the object and output it as a received signal to the amplification units 252-1 to 252-n, respectively.

The amplification units 252-1 to 252-n amplify the reception signal supplied from the reception antennas 251-1 to 251-n and output it to the synthesis unit 253-1 to 253-n, respectively.

The synthesis units 253-1 to 253-n synthesize the amplified signal of the received signal supplied from the amplification units 252-1 to 252-n and the chirp signal, respectively, and use the amplification unit 254-1 as a composite signal. Output to ~ 254-n.

The amplification units 254-1 to 254-n amplify the composite signal supplied from the synthesis unit 253-1 to 253-n and output it to the AD converters 255-1 to 255-n, respectively.

The AD converters 255-1 to 255-n perform AD conversion of the amplified composite signal supplied from the amplification units 254-1 to 254-n and output each to the signal processing unit 256.

The signal processing unit 256 calculates the distance, speed, and direction of the target object by adding the combined signals supplied from the AD converters 255-1 to 255-n and multiplying them by FFT (Fast Fourier Transform). And output as a detection result.

By adding the signals received by the plurality of receiving antennas 251 it is possible to increase the receiving sensitivity for a specific direction.

More specifically, the signal processing unit 256 has, for example, a configuration as shown in FIG. 14, and includes a distance FFT unit 271, a speed FFT unit 272, an azimuth FFT unit 273, and a DSP 274.

The distance FFT unit 271 converts a composite signal in which a chirp signal is synthesized based on the reception signal received by the reception antenna 251 into a discrete signal by applying FFT, and based on the discrete signal, reaches an object. The distance is calculated and output to DSP274.

The speed FFT unit 272 converts the composite signal in which the chirp signal is synthesized based on the received signal received by the reception antenna 251 into a discrete signal by applying FFT, and the speed of the object is based on the discrete signal. Is calculated and output to DSP274.

The azimuth FFT unit 273 converts the composite signal in which the chirp signal is synthesized based on the reception signal received by the reception antenna 251 into a discrete signal by applying the FFT, and the azimuth of the object is based on the discrete signal. Is calculated and output to DSP274.

The DSP (Digital Signal Processor) 274 digitally processes and outputs information on the distance supplied by the distance FFT unit 271, the speed supplied by the speed FFT unit 272, and the azimuth supplied by the azimuth FFT unit 273.

The calibration data generation unit 233 generates calibration data based on the detection result received by the reception unit 232 at the time of calibrating the transmission range of the radar transmission wave transmitted by the transmission unit 231, and stores the calibration data. It is stored in the part 234.

That is, the phase control unit 235 controls the phase change amount of the phase shifters 243-1 to 243-n based on the calibration data stored in the calibration data storage unit 234 to serve as the array antenna 244. Controls the transmission direction of the radar transmission wave to be transmitted.

<Configuration example of array antenna>
Next, with reference to FIG. 15, each of the element antennas 244a-1 to 244an that constitute the array antenna 244 as a whole will be described. When it is not necessary to distinguish each of the element antennas 244a-1 to 244an, it is simply referred to as an element antenna 244a.

FIG. 15 shows a configuration example of the element antenna 244a.

In order to mount the element antennas 244a-1 to 244an for forming the array antenna 244 in the limited space at the front left and right ends of the vehicle body 91a in the vehicle 91, the element antennas 244a-1 to 244an are used. It is desired that each of them is small and has high position accuracy.

The element antenna 244a of FIG. 15 is, for example, an antenna in which square copper foil patches 244p-1 to 244p-8 formed in a pattern on a high-frequency substrate are connected in series, and is generally referred to as a series-fed patch antenna. Will be done. In FIG. 15, an example in which the number of copper foil patches 244p-1 to 244p-8 is eight is shown, but the number may be other than that.

As shown in FIG. 15, the element antenna 244a is relatively inexpensive, compact, and has high position accuracy, and therefore is generally adopted as an element antenna for forming an array antenna as a whole.

The element antenna 244a composed of a series-fed patch antenna operates so as to narrow the directivity in the vertical direction by a plurality of patches 244p arranged vertically, and improves the separation performance in the vertical direction.

On the other hand, the horizontal directivity of the element antenna 244a composed of the series-fed patch antenna obtains sharp radiation characteristics as a whole by arranging the element antennas 244a in an array.

Note that the element antenna 244a is not necessarily limited to the example shown in FIG. 15, and may be any other as long as it has the same characteristics.

Using a plurality of element antennas 244a as shown in FIG. 15, the array antenna 244 as shown in FIG. 16 is configured, and the transmission range of the radar transmission wave is set. In FIG. 16, an example of the array antenna 244 when eight element antennas 244a-1 to 244a-8 are used is shown.

Here, the interval between the element antennas 244a-1 to 244a-8 in the array antenna 244 shown in FIG. 16 is usually about half the wavelength of the radar transmission wave. By arranging the element antennas 244a-1 to 244a-8 in an array in this way, it is possible to narrow the viewing angle of the transmission range of the radar transmission wave and sharpen the transmission range. In general, as the number of element antennas 244a increases, it becomes possible to form a sharper beam-shaped transmission range.

A plurality of element antennas 244a-1 to 244an configured in this way are arranged in a plurality of elements, and the amount of phase change of the phase shifters 243-1 to 243-n is controlled by the phase control unit 235. , So-called beamforming is realized, which sets the shape of the transmission range of the radar transmission wave.

<Characteristics of element antenna>
Next, with reference to FIG. 17, the characteristics of the element antenna 244a as a single unit will be described.

The left part of FIG. 17 shows a typical distribution (waveform HW, VW) of the gain in the horizontally polarized component and the vertically polarized component according to the angle in the horizontal direction of the antenna with respect to the element antenna 244a of FIG.

That is, as shown in the left part of FIG. 17, the waveform HW of the horizontally polarized component corresponding to the angle in the horizontal direction of the antenna with respect to the element antenna 244a is a waveform having a peak centered on 0 degrees with respect to the horizontal direction. is there.

Further, the waveform VW of the vertically polarized component corresponding to the angle in the horizontal direction of the antenna with respect to the element antenna 244a is a waveform that has a minimum value at 0 degrees with respect to the horizontal direction and a peak at 45 degrees symmetrically.

Further, the right part of FIG. 17 shows a typical gain distribution (waveforms HW, VW) in the horizontally polarized component and the vertically polarized component according to the angle in the vertical direction of the antenna of the element antenna 244a of FIG. ..

That is, as shown in the right part of FIG. 17, the waveform HW of the horizontally polarized component corresponding to the angle in the vertical direction of the antenna with respect to the array antenna 244 is a waveform without large unevenness with respect to all angles.

Further, the waveform VW of the vertically polarized component corresponding to the angle in the vertical direction of the antenna with respect to the array antenna 244 is a waveform that peaks at 0 degrees with respect to the vertical direction.

Further, in both the left part and the right part of FIG. 17, the gain of the vertically polarized wave component is larger than that of the horizontally polarized wave component, and it is shown that the polarized wave component is dominant.

When the array antenna 244 is configured by using a plurality of such element antennas 244a, when the radar transmission wave is incident on the vehicle body 91a such as the body or the bumper portion with the incident angle set to be large, it is reflected at the interface. There is a risk that the radar transmission wave cannot be transmitted to the transmission range in front of the vehicle 91 because the vehicle body 91a cannot be transmitted due to refraction.

<Reflection and refraction of electromagnetic waves at the dielectric interface>
A typical example of the polarization dependence of the reflection characteristic of an electromagnetic wave on a dielectric is the characteristic shown in FIG. 18, for example.

The bumper constituting the vehicle body 91a, for example, is assumed to be made of a dielectric material such as polypropylene, and its dielectric constant is about 2.2 to 2.6. Therefore, in FIG. 18, a dielectric having a dielectric constant of 2.5 The reflection characteristics at the interface of are shown.

Now, regarding the reflection / refraction phenomenon of electromagnetic waves at the dielectric interface, we will consider the phenomenon by dividing it into two polarizations, that is, p-polarization and s-polarization.

Here, the p-polarized light is a polarization component whose direction is parallel to the incoming / reflective surface of the electric field with respect to the dielectric, and the s-polarized light is a polarized light whose direction is perpendicular to the incoming / reflected surface of the electric field with respect to the dielectric. It is an ingredient.

In FIG. 17, the dotted waveform SW shows the reflection characteristic of the s polarization component, and the solid waveform PW shows the reflection characteristic of the p polarization component.

The amount of reflection of the s-polarized light component indicated by the waveform SW increases monotonically as the incident angle of the electromagnetic wave with respect to the dielectric increases. On the other hand, the p-polarized light component represented by the waveform PW gradually decreases as the incident angle of the electromagnetic wave with respect to the dielectric increases, the amount of reflection becomes zero at a predetermined incident angle, and increases again.

Generally, the incident angle BA at which the amount of reflection in the p-polarized light component is zero is known as Brewster's angle.

That is, the amount of reflection of the p-polarized light component becomes zero when the angle of incidence on the dielectric is the Brewster's angle.

For example, when the radar device 201 provided with the array antenna 244 as shown in FIG. 16 is mounted on the vehicle 91, in order to maximize the beam directivity of the transmission range of the radar transmission wave, it is inevitable. The board is erected vertically so that each of the patches 244p of the element antenna 244a is vertically connected and arranged, and mounted on the vehicle 91.

However, when each of the element antennas 244a is arranged so that the patches 244p are connected in the vertical direction and arranged side by side in this way, the main polarization component radiated from each element antenna 244a is vertically polarized, so that the radar transmission wave is generated. , When the antenna is obliquely incident on the interface with the vehicle body 91a such as the body or bumper so as to have an incident angle of a predetermined size or more, it corresponds to the s polarization component as shown by the waveform SW in FIG. The behavior has reflection characteristics.

That is, when the radar transmission wave transmitted from the radar device 201 constituting the array antenna as a whole is obliquely incident at the interface with the vehicle body 91a made of the body or bumper at an incident angle larger than a predetermined incident angle, a large reflection occurs. It will occur.

Such a large reflection is a loss of the radar transmission wave and may increase a received signal which is unfavorable for the radar device 201.

Therefore, in the range related to the transmission range of the radar transmission wave in the vehicle body 91a, a member having characteristics different from that of the conventional member made of a dielectric is arranged.

Specifically, the member 221 having a relative permittivity other than 1 is arranged in the range related to the transmission range of the radar transmission wave in the vehicle body 91a. With such a configuration, the Brewster angle is configured with respect to the s polarization component.

Generally, it is known that the Brewster angle exists for the p-polarized component, but the same phenomenon does not exist for the s-polarized component.

However, this is a result of the relative permeability of ordinary substances in nature being 1.

Therefore, by configuring the member 221 whose relative magnetic permeability is not 1 in the front stage of the radar device 201, the reflection of the radar transmission wave is suppressed.

That is, after adjusting and installing the surfaces 201fL and 201fR of the

radar devices

201R and 201L, it is possible to adjust the transmission range of the radar transmission wave by using the phase shifter 243 and the array antenna 244.

As a result, the radar transmission wave is incident on the portion of the vehicle body 91a formed by the member 221 having a relative magnetic permeability of not 1, so that the incident angle near the center of the transmission range forms a Brewster angle. , It becomes possible to adjust the transmission range to a viewing angle narrower than a predetermined viewing angle.

Therefore, when the radar transmission wave is transmitted through the portion formed by the member 221 whose relative magnetic permeability is not 1 of the vehicle body 91a, the disturbance and variation of the radar transmission wave are suppressed, and the phenomenon such as reflection or refraction is suppressed. Is possible.

As a result, it is possible to transmit the radar transmission wave with high efficiency to the transmission range set in front of the vehicle 91 (vehicle body 91a), and it is possible to improve the detection sensitivity of the radar device 201.

<Members whose relative permeability is not 1>
The member 221 having a relative magnetic permeability of not 1 includes, for example, as shown in FIG. 19, substrates PN1 to PN3 and PN11 to PN13 in which minute ring-shaped patterns M1 and M2 are repeatedly formed, which are called split ring resonators. It is arranged in a three-dimensional combination. In FIG. 19, ring-shaped patterns M1 formed so as to surround the ring-shaped pattern M2 are arranged on the substrates PN1 to PN3 and PN11 to PN13 at substantially equal intervals in the horizontal direction and the vertical direction.

Generally, a material whose dielectric constant and magnetic permeability are artificially controlled as shown in FIG. 19 is called a metamaterial material.

Metamaterial materials are materials with electrical properties that do not exist in nature by appropriately adjusting the values of relative permittivity and relative magnetic permeability.

In FIG. 19, the substrates PN1 to PN3 and PN11 to PN13 are assembled in a well shape.

Further, the incident direction of the radar transmission wave with respect to the member 221 made of the metamaterial material in FIG. 19 and having a relative magnetic permeability of not 1 is the direction indicated by the arrow in the drawing, and the substrates PN1 to PN3 (or PN11 to PN13). ) Is perpendicular to.

The dimensions per unit cell composed of the outer patterns M1 constituting the patterns M1 and M2 of the double split ring in the member 221 made of the metamaterial material shown in FIG. 19 and having a relative permittivity of not 1 are roughly the wavelengths used. It is required to be sufficiently smaller than the wavelength of the signal (approximately 0.2λ (λ is a wavelength)), and for example, 0.14λ (λ is a wavelength) is used.

That is, assuming that the frequency used is 77 GHz, the wavelength is about 4 mm, so 0.14λ corresponds to 0.56 mm. Therefore, when the operating frequency is 77 GHz, the diameter dimension of the pattern M1 on the outer peripheral side of the patterns M1 and M2 of the double dividing ring is about 0.56 mm.

On the other hand, the size of the repeating structure of the unit cell (the distance between the ring-shaped patterns M1 and M2) needs to be sufficiently large with respect to the wavelength, and for example, the size of 10 to 20 wavelengths is secured. .. In this case, the size of the repeating structure of the unit cell is about several cm.

For example, suppose that a material for which the values of the relative permittivity and the relative magnetic permeability given in FIG. 18 are exactly exchanged is realized by a member 221 made of the metamaterial material in FIG. 19 and having a relative magnetic permeability of not 1, the characteristics thereof are shown in FIG. In No. 18, the waveform SW showing the characteristics of the s polarization component and the waveform PW showing the characteristics of the p polarization component are exchanged.

Therefore, in the case of a material in which the values of the relative permittivity and the relative magnetic permeability given in FIG. 18 are exactly exchanged, there is a Brewster angle with respect to the characteristics of the s polarization component.

Theoretically, it is known that Brewster's angle occurs when the relative permeability of a substance becomes a value other than 1.

Therefore, in the present disclosure, as the member 221 having a relative magnetic permeability of not 1, a metamaterial material having a relative magnetic permeability other than 1 is previously formed, and the member 221 made of the metamaterial material is a vehicle body 91a such as a body or a bumper portion. Therefore, it is used for the part that overlaps with the transmission range of the radar transmission wave. With such a configuration, it is possible to reduce the amount of reflection and increase the amount of transmission of the radar transmitted wave output from the radar device 201 passing through the vehicle body 91a, and the sensitivity of the radar device 201. Can be increased.

For the method of generating metamaterial materials, refer to "Observation of Brewster's effect for transverse-electric electromagnetic waves in metamaterials," Physical Review B73, 193104 (2006) (hereinafter, also referred to as a reference). Further, a dimensional example (0.14λ (λ)) per unit cell composed of the outer patterns M1 constituting the patterns M1 and M2 of the double dividing ring in the member 221 made of the metamaterial material whose relative permittivity is not 1 shown in FIG. Is a wavelength)) is based on the description in the references. Further, the metamaterial material may have a structure other than the structure in which the substrates PN1 to PN3 and PN11 to PN13 are assembled in a well shape as shown in FIG. 19, for example, fixed by a resin pattern and as shown in FIG. It may be formed as a three-dimensional structure of a double split ring.

Note that this disclosure can also have the following structure.

<1> Provided with two or more vertically polarized radar transmission wave transmitters arranged so that the transmission directions of the respective radar transmission waves intersect.
A moving body in which a part of the vehicle body placed in front of the radar transmitting wave transmitting unit is a member having a relative magnetic permeability of not 1.
<2> The radar transmission wave transmitter has an array antenna and a phase shifter.
The mobile body according to <1>, wherein the phase shifter adjusts the amount of phase change of the array antenna to adjust the transmission range of the radar transmission wave transmitted from the array antenna.
<3> The array antenna is composed of a plurality of element antennas.
The mobile body according to <2>, wherein the phase shifter adjusts the phase change amount of each of the plurality of element antennas to adjust the transmission range of the radar transmission wave transmitted from the array antenna.
<4> The mobile body according to <3>, wherein each of the plurality of element antennas is a series-fed patch antenna in which copper foil patches are vertically connected in series.
<5> A part of the vehicle body in front of the array antenna, which overlaps with the transmission range of the radar transmission wave transmitted from the array antenna, is composed of a member having a relative magnetic permeability of not 1. <2> The moving body described in.
<6> The transmission range of the radar transmission wave is in the first direction which is front of the moving direction of the moving body and in the central axis of the moving body in the direction perpendicular to the moving direction of the moving body. The moving body according to <5>, which is set in a second direction in which the centers of the transmission ranges of the radar transmission waves intersect.
<7> A part of the vehicle body in front of the array antenna, which overlaps with the transmission range of the radar transmission wave transmitted from the array antenna in the second direction, is a member whose relative magnetic permeability is not 1. The moving body according to <6>.
<8> The specific reflectance of the radar transmission wave transmitted from the array antenna, which is a part of the vehicle body in front of the array antenna and overlaps with the transmission range in the second direction, is not 1. The moving body according to <7>, wherein the member is configured at a position where the radar transmission wave is incident at an incident angle that minimizes the reflectance to the member whose specific magnetic permeability is not 1.
<9> The relative magnetic permeability of the radar transmission wave transmitted from the array antenna, which is a part of the vehicle body placed in front of the array antenna and overlaps with the transmission range in the second direction, is not 1. The moving body according to <8>, wherein the member is configured at a position where the radar transmission wave is incident at a Brewster angle with respect to the member whose relative magnetic permeability is not 1.
<10> The radar transmission wave transmission unit is installed so that the transmission range of the radar transmission wave is in the first direction when the phase change amount by the phase shifter is not adjusted with respect to the array antenna. The moving body according to <6>, wherein the transmission range of the radar transmission wave is set to the second direction by adjusting the amount of phase change by the phase shifter with respect to the array antenna.
<11> The radar transmission wave transmission unit is installed so that the transmission range of the radar transmission wave is in the second direction when the phase change amount by the phase shifter is not adjusted with respect to the array antenna. The moving body according to <6>, wherein the transmission range of the radar transmission wave is set to the first direction by adjusting the amount of phase change by the phase shifter with respect to the array antenna.
<12> The moving body according to any one of <1> to <11>, which is a metamaterial material, is the member whose relative magnetic permeability is not 1.
<13> The moving body according to <12>, wherein the metamaterial material is a split ring resonator.
<14> The moving body according to <13>, wherein the split ring resonator is a board in which a substrate having a minute ring-shaped pattern is formed is assembled in a well shape.
<15> The moving body according to <14>, wherein the diameter of the minute ring-shaped pattern is smaller than approximately 0.2 times the wavelength of the radar transmission wave.
<16> The moving body according to <14>, wherein the arrangement interval of the minute ring-shaped pattern is approximately 10 to approximately 20 times the wavelength of the radar transmission wave.
<17> The moving body according to <13>, wherein the split ring resonator is a micro ring-shaped pattern made of resin formed as a three-dimensional structure.

91 mobile body (vehicle), 91a car body, 201, 201L, 201R, 201L', 201R'radar device, surface formed by 201fL, 201fR array antenna, 244, 244-1 to 244-n array antenna, 244a patch

Claims

It is equipped with two or more vertically polarized radar transmission wave transmitters arranged so that the transmission directions of the respective radar transmission waves intersect.
A moving body in which a part of the vehicle body placed in front of the radar transmitting wave transmitting unit is a member having a relative magnetic permeability of not 1.
The radar transmission wave transmitter has an array antenna and a phase shifter.
The mobile body according to claim 1, wherein the phase shifter adjusts the amount of phase change of the array antenna to adjust the transmission range of the radar transmission wave transmitted from the array antenna.
The array antenna is composed of a plurality of element antennas.
The mobile body according to claim 2, wherein the phase shifter adjusts the phase change amount of each of the plurality of element antennas to adjust the transmission range of the radar transmission wave transmitted from the array antenna.
The mobile body according to claim 3, wherein each of the plurality of element antennas is a series-fed patch antenna in which copper foil patches are vertically connected in series.
The second aspect of claim 2, wherein a part of the vehicle body placed in front of the array antenna, which overlaps with the transmission range of the radar transmission wave transmitted from the array antenna, is composed of a member having a relative magnetic permeability of not 1. Mobile body.
The transmission range of the radar transmission wave is the first direction that is front of the moving direction of the moving body and the central axis of the moving body that is perpendicular to the moving direction of the moving body. The mobile body according to claim 5, which is set in a second direction in which the center of the transmission range of the radar transmission wave intersects.
A part of the vehicle body placed in front of the array antenna, which overlaps the transmission range of the radar transmission wave transmitted from the array antenna in the second direction, is composed of a member having a relative magnetic permeability of not 1. The moving body according to claim 6.
The member whose specific reflectance is not 1 and which is a part of the vehicle body placed in front of the array antenna, which overlaps with the transmission range of the radar transmission wave transmitted from the array antenna in the second direction, is The moving body according to claim 7, wherein the radar transmission wave is configured at a position where the radar transmission wave is incident at an incident angle that minimizes the reflectance to the member whose specific magnetic permeability is not 1.
The member having a relative magnetic permeability of not 1 which is a part of the vehicle body placed in front of the array antenna and which overlaps with the transmission range of the radar transmission wave transmitted from the array antenna in the second direction is The moving body according to claim 8, wherein the radar transmission wave is configured at a position where the radar transmission wave is incident at a Brewster angle with respect to the member whose relative magnetic permeability is not 1.
The radar transmission wave transmission unit is installed so that the transmission range of the radar transmission wave is in the first direction when the amount of phase change by the phase shifter is not adjusted with respect to the array antenna. The moving body according to claim 6, wherein the transmission range of the radar transmission wave is set to the second direction by adjusting the amount of phase change by the phase shifter.
The radar transmission wave transmitter is installed so that the transmission range of the radar transmission wave is in the second direction when the amount of phase change by the phase shifter is not adjusted with respect to the array antenna. The moving body according to claim 6, wherein the transmission range of the radar transmission wave is set to the first direction by adjusting the amount of phase change by the phase shifter.
The moving body according to claim 1, wherein the member having a relative magnetic permeability of not 1 is a metamaterial material.
The moving body according to claim 12, wherein the metamaterial material is a split ring resonator.
The moving body according to claim 13, wherein the split ring resonator is formed by assembling a substrate on which a minute ring-shaped pattern is formed into a well shape.
The mobile body according to claim 14, wherein the diameter of the minute ring-shaped pattern is smaller than approximately 0.2 times the wavelength of the radar transmission wave.
The mobile body according to claim 14, wherein the arrangement interval of the minute ring-shaped pattern is approximately 10 to approximately 20 times the wavelength of the radar transmission wave.
The moving body according to claim 13, wherein the split ring resonator is a micro ring-shaped pattern made of resin formed as a three-dimensional structure.