WO2018000667A1

WO2018000667A1 - Imaging radar, vehicle and imaging method

Info

Publication number: WO2018000667A1
Application number: PCT/CN2016/103167
Authority: WO
Inventors: 戴春杨; 高明亮; 于彬彬; 赵捷
Original assignee: 北京行易道科技有限公司
Priority date: 2016-06-30
Filing date: 2016-10-25
Publication date: 2018-01-04
Also published as: CN107561532A

Abstract

An imaging radar, a vehicle and an imaging method. The imaging radar comprises: an emitting antenna (10) provided on a side surface of a vehicle and coupled to a radio frequency module (30), used to emit a signal generated by the radio frequency module (30); a receiving antenna (20) provided on a side surface of the vehicle and coupled to the radio frequency module (30), used to receive a scattered signal generated by target objects around the vehicle scattering the signal emitted by the emitting antenna (10); a radio frequency module (30) coupled to a processor (40), used to generate a signal to be emitted, and form the scattered signal received via the receiving antenna (20) into echo data; a processor (40), used to collect echo data via the radio frequency module (30) as the vehicle moves, and generate a three-dimensional radar image according to said echo data. The present invention solves problems related to obtaining information on the driving environment surrounding a car by means of using a camera to collect images, allowing vehicle radar to adapt to any environment and lowering processing load to a certain degree.

Description

Imaging radar, vehicle, and imaging method

Technical field

The present application relates to the field of radar, and in particular to imaging radars, vehicles, and imaging methods.

Background technique

In order to make the vehicle safer, or to adapt to the need for automatic driving in the future, it is necessary to obtain the environmental conditions around the car. In the prior art, the sensor installed on the vehicle can be used to collect and analyze the two-dimensional image data around the car at any time during the driving process, so that the driver can detect the danger that may occur in advance, and can effectively increase the safety of the driving of the car. Sex.

In the prior art, two-dimensional data is obtained by a visual camera, that is, a visual camera is used to acquire image data of a surrounding environment, so that the surrounding environment of the automobile can be perceived. Real-time monitoring of objects around the car through the camera, coupled with an algorithm to calculate the distance between the object and the vehicle, thus achieving lane departure warning, front vehicle collision avoidance, pedestrian detection and other functions.

The visual camera is used as a sensor to obtain two-dimensional image data of the surrounding environment of the automobile. Since the camera adopts a method of taking photos directly to the surrounding environment, the direct photographing method is susceptible to factors such as illumination and weather. In the environment of night, glare, fog, rain and snow, because the light is not good, the shooting effect is not very good, which will result in the inability to directly distinguish the distance between the object and the vehicle in the environment, thus making the original vehicle Some features are almost impossible to work properly. In addition, since the image data is directly processed, useful information is extracted from the image data, which results in a large amount of data and a serious calculation overhead. Moreover, in order to make the calculation more rapid, it is necessary to use an expensive digital signal processing chip, which is costly.

A solution to the problem caused by the use of a camera to acquire an image in the related art to obtain a driving environment around the vehicle has not been proposed.

Summary of the invention

The present application provides an imaging radar, a vehicle, and an imaging method to at least solve the problem caused by using a camera to acquire images to obtain a driving environment around the vehicle.

According to an aspect of the present application, an imaging radar is provided, comprising: a transmitting antenna disposed on a side of a vehicle, coupled to a radio frequency module, configured to transmit a signal generated by the radio frequency module; and a receiving antenna disposed with the vehicle a side surface coupled to the radio frequency module for receiving a scatter signal formed by scattering of a signal transmitted by a target around the vehicle to a transmit antenna; the radio frequency module coupled to the processor for generating a location for transmitting a signal, and the scatter signal received by the receiving antenna to form echo data; the processor, configured to acquire, by the radio frequency module, echo data transmitted along with the vehicle motion, and according to the The echo data is generated to generate a two-dimensional radar image.

Further, the radio frequency module includes: an oscillator for generating a signal for transmitting; a first power amplifier coupled to the oscillator and the transmitting antenna for amplifying and transmitting the signal to the a transmit antenna for transmitting; a second power amplifier coupled to the mixer and the receive antenna for amplifying the received scatter signal and transmitting to the mixer; the mixer, coupled And the second power amplifier and the oscillator are configured to mix the signal and the scatter signal to generate the echo data.

Further, the transmitting antennas are one or more, and the receiving antennas are one or more.

Further, the processor is configured to acquire echo data transmitted by the vehicle motion, form a synthetic aperture according to the echo data, and generate a two-dimensional radar image.

Further, the radio frequency module is configured to generate millimeter waves as the transmitted signals.

According to another aspect of the present application, there is also provided a vehicle comprising: the imaging radar described above.

Further, the imaging radar is disposed on a side of the vehicle.

Further, the imaging radar is disposed at a side of the vehicle at a predetermined distance from a rear wheel of the vehicle and/or a front wheel of the vehicle.

Further, the imaging radar is disposed at a side of the vehicle at a predetermined distance from a headlight of the vehicle and/or a backlight of the vehicle.

Further, the imaging radar is one or more.

According to another aspect of the present application, there is also provided an imaging method comprising: transmitting a signal; receiving a scatter signal formed by scattering of the transmitted signal by a target around the vehicle; forming the scatter signal received into an echo Data; acquiring echo data transmitted back with the vehicle motion, and generating a two-dimensional radar image based on the echo data.

Further, generating the two-dimensional radar image according to the echo data comprises: forming a synthetic aperture according to the echo data to generate a two-dimensional radar image.

Further, generating the two-dimensional radar image according to the echo data includes: performing Fourier transform on the echo data, waiting for the transformed data; and obtaining pixel points according to the transformed data, The pixel calculates a distance history and a scattering intensity; the two-dimensional radar image is obtained from the distance history and the scattering intensity.

Further, the transmitting antenna transmitting the signal is one or more, and the receiving antenna receiving the scattered signal is one or more.

Further, the signal is a millimeter wave signal.

An imaging radar is used in the present application, the imaging radar includes: a transmitting antenna disposed on a side of the vehicle, coupled to the radio frequency module, configured to transmit a signal generated by the radio frequency module; and a receiving antenna disposed on a side of the vehicle, and The radio frequency module is coupled for receiving a scatter signal formed by scattering of a signal transmitted by a target around the vehicle to a transmit antenna; the radio frequency module coupled to the processor for generating the signal for transmission, and Forming the scatter signal received by the receiving antenna to form echo data; the processor, configured to acquire, by the radio frequency module, echo data transmitted along with the vehicle motion, and according to the echo data Generate a 2D radar image. The problem caused by using the camera to collect images to obtain the driving environment around the vehicle is solved, so that the vehicle radar can adapt to various environments and reduce the processing load to some extent.

DRAWINGS

The drawings described herein are intended to provide a further understanding of the present application, and are intended to be a part of this application. Moreover, other drawings may be obtained from those of ordinary skill in the art based on these drawings without undue creative work. In the drawing:

1 is a block diagram showing the structure of an imaging radar according to the present embodiment;

2 is a flow chart of an imaging method according to the present embodiment;

Figure 3 is a schematic illustration of an imaging radar setup in accordance with the present embodiment;

4 is a block diagram showing the structure of an optional two-dimensional imaging radar according to the present embodiment;

FIG. 5 is a schematic structural diagram of a radio frequency module according to the embodiment; FIG.

Fig. 6 is a flow chart showing the internal processing of the signal processor according to the present embodiment.

detailed description

It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings.

It should be noted that the steps shown in the schematic diagram of the drawing may be executed in a computer system such as a set of computer executable instructions, and although the logical sequence is shown in the flow diagram, in some cases, The steps shown or described may be performed in an order different than that herein.

In the present embodiment, an imaging radar is provided. FIG. 1 is a structural block diagram of an imaging radar according to the present embodiment. As shown in FIG. 1, the imaging radar includes: a transmitting antenna 10 disposed on a side of the vehicle, and a radio frequency. The module 30 is coupled for transmitting signals generated by the radio frequency module 30; the receiving antenna 20 is disposed with the side of the vehicle, and the radio frequency Module 30 is coupled for receiving a scatter signal formed by scattering of a signal transmitted by a target around the vehicle to transmit antenna 10; radio frequency module 30 coupled to processor 40 for generating a signal for transmission, and to pass through receive antenna 20 The received scatter signal forms echo data; the processor 40 is configured to acquire echo data transmitted by the vehicle motion through the radio frequency module 30, and generate a two-dimensional radar image according to the echo data.

Through the above imaging radar, the processing of the signal is used, and the characteristics of the vehicle's continuous motion are utilized, so that the radar can be used to identify the target around the vehicle, thereby solving the problem caused by using the camera to acquire images to obtain the driving environment around the vehicle, so that Vehicle radar can adapt to various environments and reduce the processing load to a certain extent.

There are many implementations of the RF module 30. In this embodiment, an alternative implementation is provided. The radio frequency module 30 can include an oscillator (which can employ a voltage controlled oscillator) for generating a signal for transmission, and a first power amplifier coupled to the oscillator and the transmit antenna 10 for amplifying the signal and transmitting to the transmission The antenna 10 is transmitting; a second power amplifier coupled to the mixer and the receiving antenna 20 for amplifying the received scattered signal and transmitting it to the mixer; a mixer coupled to the second power amplifier and oscillating For mixing the signal and the scatter signal to generate echo data. A power amplifier is used in this embodiment, so that the scattering of the signal and the identification of the scattered signal can be more favored.

In an optional embodiment, since the two-dimensional image needs to be generated, at this time, the transmitting antenna 10 and the receiving antenna 20 may be one. Of course, there may be multiple, and multiple transmitting antennas 10 and receiving may be utilized. Antenna 20 comes to verify the scattered signal, resulting in more realistic and reliable echo data.

In an alternative embodiment, a synthetic aperture can be utilized to generate a two-dimensional radar image. At this time, the processor 40 is configured to acquire echo data transmitted by the vehicle motion, form a synthetic aperture according to the echo data, and generate a two-dimensional radar image.

The transmitted signal can be processed using a variety of waves. In a preferred embodiment, the RF module 30 is used to generate a millimeter wave as the transmitted signal.

In the embodiment, a vehicle is further provided, comprising: the imaging radar described above. The imaging radar can be set at a position that can be set, and can be selected according to actual needs. For example, the imaging radar is disposed on the side of the vehicle. An imaging radar can be provided at a plurality of locations on the side of the vehicle, for example, on the side of the vehicle at a predetermined distance from the rear wheel of the vehicle and/or the front wheel of the vehicle. As another example, an imaging radar is disposed on a side of a vehicle that is a predetermined distance from a headlight of the vehicle and/or a backlight of the vehicle. The imaging radar described above may be one or more.

In the embodiment, an imaging method is also provided, and FIG. 2 is a flowchart of the imaging method according to the embodiment. As shown in FIG. 2, the method includes the following steps:

Step S202, transmitting a signal;

Step S204, receiving a scatter signal formed by scattering a signal transmitted by a target around the vehicle;

Step S206, forming the received scatter signal into echo data;

Step S208, acquiring echo data transmitted along with the vehicle motion, and generating a two-dimensional radar image according to the echo data.

Through the above steps, the processing of the signal is used, and the characteristics of the vehicle's continuous motion are utilized, so that the radar can be used to identify the target around the vehicle, thereby solving the problem caused by using the camera to acquire images to obtain the driving environment around the vehicle, and making the vehicle Radar can adapt to a variety of environments and to some extent reduce the processing load.

In an alternative embodiment, a synthetic aperture can be formed from the echo data to generate a two-dimensional radar image. For example, the echo data is subjected to Fourier transform, and the transformed data is waited; the pixel points are obtained according to the transformed data, the distance history and the scattering intensity are calculated for the pixel points; and the two-dimensional radar image is obtained according to the distance history and the scattering intensity.

In an optional embodiment, the present application may also provide a computer program for executing the above embodiment and a carrier for saving the above computer program, that is, the above embodiment of the present application can conform to nature through a suitable computing architecture. Regular running process. In addition, although the present application is described in the above context, the above-described computer program for implementing the execution steps is not meant to be limiting, and various aspects of the described actions and operations may also be implemented in hardware.

The principles of the application can be operated using other general purpose or special purpose computing or communication environments or configurations. Examples of well-known computing systems, environments, and configurations suitable for use with the present application include, but are not limited to, personal computers, servers, multiprocessor systems, microprocessor based systems, minicomputers, mainframe computers, smart devices, terminals (including mobile terminals) And a distributed computing environment including any of the above systems or devices.

The implementation process will be described in detail below in conjunction with an alternative embodiment.

In the present embodiment, a millimeter wave two-dimensional imaging radar for safe driving of a vehicle is provided. Since the millimeter wave is used, the alternative embodiment can operate normally in any lighting environment and any weather environment. Moreover, the imaging radar has a relatively small amount of data compared to the camera, and the calculation amount is smaller than the calculation amount of the camera acquisition mode, and the calculation amount is moderate for the vehicle.

For the selection of imaging radar, a millimeter wave imaging radar is used in this embodiment. Of course, it is also possible to use a meter wave, a decimeter wave or a centimeter band radar. In this embodiment, the millimeter wave imaging radar is used in comparison with other common radar frequency bands, for example, the meter wave, the decimeter wave, and the centimeter wave band. The millimeter wave band radar has the following advantages: the radar operating wavelength is short, and the smaller antenna size can Achieve higher angular resolution; RF transceiver chip integration is high, the entire radar RF front end can be completed with a millimeter wave RF chip; based on the highly integrated radar RF front end, the whole machine radar cost is relatively low.

In the present embodiment, the millimeter-wave radar two-dimensional imaging radar can achieve high scores in the distance direction and the azimuth direction. Identify. Among them, the radar can transmit a large bandwidth signal, and the pulse compression technology is used to achieve a high resolution of the distance. Since the imaging radar is mounted on the vehicle, the vehicle is constantly moving. Therefore, the imaging radar can also be moved, so that the imaging radar utilizes its own motion, and there is a difference in the Doppler frequency of the echoes of different azimuth targets, and Doppler processing is performed to achieve high resolution in the azimuth direction.

3 is a schematic diagram of an imaging radar arrangement according to the present embodiment. As shown in FIG. 3, the millimeter wave two-dimensional imaging radar according to the embodiment may be placed on the side of the vehicle body (for example, may be disposed near the side of the vehicle side). Or, near the edge of the rear door, or above the front wheel of the vehicle, the two-dimensional imaging radar mainly uses the car's own motion to form a synthetic aperture to achieve two-dimensional imaging of the radar.

In this embodiment, an imaging radar is involved. In the embodiment, a two-dimensional imaging radar can be used in consideration of the amount of calculation. There are many ways to construct a two-dimensional imaging radar. In this embodiment, a structural block diagram of an optional two-dimensional imaging radar is provided, and FIG. 4 is a structural block diagram of an optional two-dimensional imaging radar according to the embodiment. As shown in FIG. 4, the millimeter wave two-dimensional imaging radar may include: a transmitting and receiving antenna, a radio frequency module, and a signal processor. In FIG. 4, one transmitting antenna and one receiving antenna are included, and of course, there may be multiple transmitting antennas and receiving antennas. A large number of antennas can be distributed in different places of the antenna, so that signals of the radar can be transmitted and received, and these signals can also be processed, so that the obtained two-dimensional image is more accurate. If the cost problem is considered, a transmitting antenna and a receiving antenna may be provided. The signals of these antennas may be configured by the radio frequency module to transmit signals, and the transmitting antennas emit electromagnetic waves; the electromagnetic waves are scattered by the target in the observation area, and the receiving antenna receives the target. The signal is scattered and transmitted by the RF module to the signal processor (the signal processor can be understood as a processor).

There are also many implementations of the radio frequency module. In this embodiment, an optional implementation manner is provided. FIG. 5 is a schematic structural diagram of the radio frequency module according to the embodiment. As shown in FIG. 5, the voltage control oscillator can be used. A transmit signal is generated that is transmitted by the transmit antenna through a power amplifier. The receiving antenna receives the target echo, passes through the power amplifier, and mixes with the transmitted signal generated by the voltage controlled oscillator, and finally transmits the mixed radar echo data to the signal processor.

There are also a variety of processing methods inside the signal processor. FIG. 6 provides an alternative manner. FIG. 6 is a flowchart of internal processing of the signal processor according to the embodiment. In FIG. 6, the radar echo data is used. (t, u) indicates that t represents fast time and u represents slow time. As shown in FIG. 6, the process includes the following steps:

In step S1, the radar echo data s(t, u) is subjected to Fourier transform according to the fast time t, and the transformed data S(f, u) is obtained, that is,

S(f,u)=∫s(t,u)exp(-j2πft)dt (1)

Step S2, for the pixel points (x _n , y _n ) (n=1, 2, . . . , N) in the radar image, calculate the distance history according to the following formula, ie,

Wherein, the y-axis represents a vehicle motion direction vector; the x-axis represents a direction vector of the vehicle that is perpendicular to the y-axis and lies in a ground plane;

Indicates the coordinates of the car in the x direction;

Indicates the coordinates of the car in the y direction; h represents the height of the radar relative to the ground plane; v represents the speed of the car's motion; x _n and y _n represent the coordinates of the image pixel points on the x and y axes, respectively.

Step S3, for the pixel points (x _n , y _n ) (n=1, 2, . . . , N) in the radar image, calculate the scattering intensity value according to the following formula, ie,

Where B is the bandwidth of the transmitted signal; T is the width of the transmitted signal; f _c is the operating frequency of the radar; c is the propagation speed of the electromagnetic wave.

In this embodiment, the millimeter wave two-dimensional imaging radar is disposed on the side of the automobile, and performs radar imaging on the side target. The millimeter wave two-dimensional imaging radar may include: a transmitting antenna, a receiving antenna, a radio frequency module, and a signal processing module. Then, through the millimeter wave two-dimensional imaging radar signal processing method, the radar echo data is processed to finally obtain the radar image.

The above preferred embodiments can be used in combination. Also, as used herein, the term "module" or "unit" may refer to a software object or routine that is executed on the apparatus described above. The various modules and units described herein can be implemented as objects or processes executing on the above-described devices (eg, as separate threads), while implementations of the above-described devices using hardware or a combination of software and hardware are also possible and contemplated. .

Obviously, those skilled in the art should understand that the above modules or steps of the present application can be implemented by a general computing device, which can be concentrated on a single computing device or distributed in a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in a storage device by a computing device, or they may be fabricated into individual integrated circuit modules, or Multiple modules or steps are made into a single integrated circuit module. Thus, the application is not limited to any particular combination of hardware and software.

The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Claims

An imaging radar, comprising:

a transmitting antenna, disposed on a side of the vehicle, coupled to the radio frequency module, configured to transmit a signal generated by the radio frequency module;

a receiving antenna coupled to a side of the vehicle and coupled to the radio frequency module for receiving a scatter signal formed by scattering of a signal transmitted by a target around the vehicle to a transmitting antenna;

The radio frequency module is coupled to the processor for generating the signal for transmitting, and forming the scatter signal received by the receiving antenna to form echo data;

The processor is configured to acquire echo data transmitted by the vehicle motion through the radio frequency module, and generate a two-dimensional radar image according to the echo data.
The imaging radar of claim 1 wherein said radio frequency module comprises:

An oscillator for generating a signal for transmission;

a first power amplifier coupled to the oscillator and the transmit antenna for amplifying the signal and transmitting to the transmit antenna for transmission;

a second power amplifier coupled to the mixer and the receiving antenna for amplifying the received scatter signal and transmitting to the mixer;

The mixer is coupled to the second power amplifier and the oscillator for mixing the signal and the scattered signal to generate the echo data.
The imaging radar according to claim 1, wherein said transmitting antennas are one or more, and said receiving antennas are one or more.
The imaging radar according to claim 1, wherein said processor is configured to acquire echo data transmitted along with said vehicle motion, form a synthetic aperture based on said echo data, and generate a two-dimensional radar image.
The imaging radar according to any one of claims 1 to 4, wherein the radio frequency module is configured to generate millimeter waves as the transmitted signals.
A vehicle comprising: the imaging radar of any one of claims 1 to 5.
The vehicle of claim 6 wherein said imaging radar is disposed on a side of said vehicle.
The vehicle according to claim 7, wherein the imaging radar is disposed at a side of the vehicle at a predetermined distance from a rear wheel of the vehicle and/or a front wheel of the vehicle.
The vehicle according to claim 7, wherein said imaging radar is disposed at a headlight from said vehicle And/or the side of the vehicle at a predetermined distance from the backlight of the vehicle.
A vehicle according to any one of claims 6 to 9, wherein the imaging radar is one or more.
An imaging method, comprising:

transmit a signal;

Receiving a scatter signal formed by scattering of the transmitted signal by a target around the vehicle;

Forming the received scatter signal into echo data;

Acquiring echo data transmitted along with the vehicle motion, and generating a two-dimensional radar image based on the echo data.
The method of claim 11 wherein generating the two-dimensional radar image from the echo data comprises:

A synthetic aperture is formed based on the echo data to generate a two-dimensional radar image.
The method of claim 12, wherein generating the two-dimensional radar image from the echo data comprises:

Performing a Fourier transform on the echo data, and waiting for the transformed data;

Obtaining a pixel point according to the transformed data, and calculating a distance history and a scattering intensity for the pixel point;

The two-dimensional radar image is obtained based on the distance history and the scattering intensity.
The method according to any one of claims 11 to 13, wherein the transmitting antenna transmitting the signal is one or more, and the receiving antenna receiving the scattered signal is one or more.
The method according to any one of claims 11 to 13, wherein the signal is a millimeter wave signal.