Distributed radar device and system, automobile, distributed radar detection method, computer readable storage medium and electronic equipment

Abstract

The invention provides a distributed radar device, which comprises a first radar unit and a second radar unit, and is characterized in that transmitting and receiving antenna arrays in the first radar unit and the second radar unit are placed on the same horizontal line at an interval larger than the placement range of a single radar horizontal array; each of the transmitting and receiving antenna arrays comprises a transmitting antenna array and a receiving antenna array; the transmitting antenna array comprises transmitting antennas positioned at four vertex positions in an array placement range and uniformly distributed transmitting antennas positioned on horizontal connecting lines of the vertex transmitting antennas; the receiving antenna array comprises receiving antennas which are sequentially arranged at the right side half-wavelength interval, the right side half-wavelength interval, the upper minimum interval and the left side half-wavelength interval of the transmitting antennas at the corresponding vertexes along the anticlockwise direction by taking the transmitting antenna at the first vertex at the left upper part as a starting point, and a plurality of other uniformly arranged receiving antennas. And the angle resolution in pitching and horizontal directions is improved.

Description

Technical Field

[0001] The present invention relates to the field of automobile radar positioning, and in particular to a distributed radar device, a system, an automobile, a distributed radar detection method, a computer-readable storage medium and an electronic device. Background Art

[0002] Millimeter wave radar is a key perception technology for automotive and industrial applications. In dense urban driving scenarios, advanced autonomous driving requires radars with higher angular resolution to accurately predict object trajectories and make autonomous driving decisions. Improving the angular resolution of radar can be solved by increasing the aperture of the antenna array. Due to the physical size and weight limitations of the sensor placed in the front of the car, a single sensor with a very large physical size cannot be used, and it is impossible to continuously increase the number of antennas on a single sensor to obtain a larger aperture and improve the angular resolution.

[0003] Distributed radar networks are another solution that can achieve high-resolution radar. This solution is commercially attractive because each sensor component installed on the front of the car can maintain a small physical size and simple analog circuit structure, transferring hardware complexity to software. However, the current proposed vehicle-mounted coherent radar networks have very limited improvements in the angle resolution capability of the pitch dimension, and the technical difficulty of establishing the time, frequency and phase synchronization between signals required for coherence is high, making it difficult to achieve a truly distributed network architecture without physical connections.

[0004] Therefore, developing a radar device that does not require hardware connection and has a larger virtual aperture, a larger vertical array aperture, and a distributed radar device that can achieve improved angular resolution in both the elevation and horizontal directions has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0005] In order to overcome the above technical defects, the purpose of the present invention is to provide a distributed radar device, system, automobile, distributed radar detection method, computer-readable storage medium and electronic device. In the present invention, each radar unit is arranged with a specific antenna array and placed at an interval greater than the horizontal array placement range of a single radar, so that the virtual radar array obtained can maximize the virtual aperture of a single radar unit, while maximizing the array aperture in the vertical direction, and obtaining an improvement in the angular resolution in the pitch and horizontal directions.

[0006] A first aspect of the present invention discloses a distributed radar device, comprising:

[0007] A first radar unit and a second radar unit, wherein the transceiver antenna array in the first radar unit and the transceiver antenna array in the second radar unit are placed on the same horizontal line at a distance greater than the placement range of a single radar horizontal array;

[0008] The transceiver antenna array in the first radar unit and the transceiver antenna array in the second radar unit both include: a transmitting antenna array and a receiving antenna array;

[0009] The transmitting antenna array comprises: a plurality of transmitting antennas located at four vertex positions within the array placement range, and a plurality of evenly arranged transmitting antennas located on a horizontal connection line of the vertex transmitting antennas;

[0010] The receiving antenna array includes: starting from the transmitting antenna at the first vertex position on the upper left, receiving antennas are arranged in sequence in a counterclockwise direction at the right half-wavelength interval, the right half-wavelength interval, the upper minimum interval and the left half-wavelength interval of the corresponding vertex position transmitting antenna, and other uniformly arranged receiving antennas; the minimum interval is the size of a single array element.

[0011] Optionally, the transmitting antenna at the vertex position is arranged at a position of the maximum size of the range in which the array elements in the radar unit can be placed, and the intervals between the vertex array elements satisfy an integer multiple of half a wavelength.

[0012] A second aspect of the present invention further discloses a distributed radar system, comprising:

[0013] The distributed radar device as described above in the present invention;

[0014] The distributed radar device comprises: the first radar unit and the second radar unit, which are used to respectively transmit radar transmission signals and receive echo signals transmitted by the first radar unit and other radar units after being reflected by target objects;

[0015] The distributed radar system further comprises:

[0016] The central control platform is used to generate and trigger the first radar unit and the second radar unit to transmit radar transmission signals through a frame trigger signal, and to obtain the echo signals fed back by the first radar unit and the second radar unit and transmitted by themselves and other radar units after being reflected by the target object;

[0017] It is also used to perform channel separation on the echo signals of the radar transmission signals received by the first radar unit and the second radar unit and the echo signals received by other radar units;

[0018] And it is used to select the echo signal of the cross channel in the echo signal, perform synchronous parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronous echo signal, and estimate the distance, speed and angle of the target object according to the synchronous echo signal.

[0019] Optionally, the central control platform includes: a channel separation module, a signal synchronization module and an echo signal coherent processing module;

[0020] The channel separation module is used to perform channel separation on the echo signals of the radar transmission signals received by the first radar unit and the second radar unit and the echo signals received by other radar units;

[0021] The signal synchronization module is used to select the echo signal of the cross channel in the echo signal, perform synchronization parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronized echo signal, and output it to the echo signal coherent processing module;

[0022] The echo signal coherent processing module is used to estimate the distance, speed and angle of the target object according to the synchronous echo signal.

[0023] The third aspect of the present invention further discloses a car of the present invention, comprising the distributed radar system as described in the second aspect of the present invention.

[0024] A fourth aspect of the present invention further discloses a distributed radar detection method, which is applied to the distributed radar system described in the second aspect of the present invention, and the method comprises:

[0025] The central control platform generates a frame trigger signal and sends it to the first radar unit and the second radar unit;

[0026] After receiving the frame trigger signal, the first radar unit and the second radar unit respectively transmit the transmitting radar transmission signal, and simultaneously receive the echo signal of their own radar transmission signal and the echo signal of other radar units, and feed back to the central control platform;

[0027] The central control platform receives the echo signal and performs channel separation on the echo signal from the respective radar transmission signals received by the first radar unit and the second radar unit and the echo signal received by other radar units;

[0028] Selecting the echo signal in the cross channel, performing synchronization parameter estimation on the frequency and phase of the echo signal in the cross channel to obtain a synchronous echo signal;

[0029] The distance, speed and angle of the target object are estimated according to the synchronous echo signal.

[0030] Optionally, the channel separation module performs channel separation on the echo signals of the respective radar transmission signals received by the first radar unit and the second radar unit and the echo signals of other radar units;

[0031] The signal synchronization module selects the echo signal of the cross channel, performs synchronization parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronized echo signal, and outputs the synchronized echo signal to the echo signal coherent processing module;

[0032] The echo signal coherent processing module estimates the distance, speed and angle of the target object according to the synchronous echo signal.

[0033] In a fifth aspect of the present invention, a computer-readable storage medium is further disclosed, on which a computer program is stored. When the computer program is executed by a processor, the steps of the distributed radar detection method as described in the fourth aspect of the present invention are implemented.

[0034] In a sixth aspect of the present invention, an electronic device is disclosed, comprising a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps of the distributed radar detection method as described in the fourth aspect of the present invention are implemented.

[0035] Compared with the prior art, the above technical solution has the following beneficial effects:

[0036] 1. By using the above-mentioned specific antenna array arrangement for each radar unit and placing it at a spacing greater than the horizontal array placement range of a single radar, the virtual aperture of a single radar unit can be maximized, that is, three times the horizontal aperture of a single radar, while maximizing the array aperture in the vertical direction, thereby achieving an improvement in the angular resolution in the pitch and horizontal directions.

[0037] 2. Through channel separation and signal synchronization, cross channels are added, and the frequency and phase of the echo signals of the cross channels are synchronized and estimated, thus achieving the technical effect of radar positioning by using a virtual array equivalent to the synchronized echo signal.

[0038] 3. The central control platform realizes the synchronization of time, frequency and phase at the signal processing end through software algorithms. The central control platform sends frame trigger signals for frame synchronization, realizing signal coherent processing between distributed radar units without hardware connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of an array arrangement of six-receive and six-transmit transceiver antennas in accordance with an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of an arrangement of array elements DP1\DP2 of a first radar unit and a second radar unit and a virtual radar array CP1\CP2 formed by two cross channels in accordance with an embodiment of the present invention;

[0041] Figure 3A real-life view of the installation location of a distributed radar device in accordance with an embodiment of the present invention;

[0042] Figure 4 A schematic diagram of the structure of a distributed radar system in accordance with an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of a distributed radar detection method according to an embodiment of the present invention;

[0044] Reference numerals:

[0045] 1- first radar unit;

[0046] 11- transceiver antenna array in the first radar unit;

[0047] 2- Second radar unit;

[0048] 21- transceiver antenna array in the second radar unit;

[0049] 3- Central control platform;

[0050] 4- echo signal coherent processing module;

[0051] 5-channel separation module;

[0052] 6-Signal synchronization module;

[0053] 7- Transmitting antenna;

[0054] 8- Receiving antenna;

[0055] 9-Virtual array. DETAILED DESCRIPTION

[0056] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0057] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0058] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0059] In the description of the present invention, it is necessary to understand that the terms "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0060] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0061] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0062] The present invention provides a distributed radar device, which includes: a first radar unit 1 and a second radar unit 2. The first radar unit 1 and the second radar unit 2 both include a transceiver antenna array. Figure 1 , Figure 1 A transceiver antenna array in accordance with an embodiment of the present invention is shown; the array in the left figure is the transceiver antenna array 11 in the first radar unit, and the array in the right figure is the transceiver antenna array 21 in the second radar unit.

[0063] The transceiver antenna array in the first radar unit 1 and the transceiver antenna array in the second radar unit 2 are placed on the same horizontal line with a spacing greater than the horizontal array placement range of a single radar.

[0064] The transceiver antenna array in the first radar unit 1 and the transceiver antenna array in the second radar unit 2 both include: a transmitting antenna array and a receiving antenna array.

[0065] The transmitting antenna array includes: a plurality of transmitting antennas 7 located at four vertex positions within the array placement range, and a plurality of transmitting antennas 7 evenly arranged on a horizontal connection line of the transmitting antennas 7 at the vertex positions.

[0066] The receiving antenna array includes: starting from the transmitting antenna 7 at the first vertex position on the upper left, the receiving antennas 8 arranged in sequence at the right half-wavelength interval, the right half-wavelength interval, the upper minimum interval, and the left half-wavelength interval of the corresponding vertex position transmitting antenna 7 in a counterclockwise direction, and other uniformly arranged receiving antennas 8; the minimum interval is the size of a single array element. In this embodiment, the transmitting antenna 7 at the vertex position is arranged at the maximum size position of the array element placement range in the radar unit, and the interval between the vertex array elements satisfies an integer multiple of a half wavelength; the maximum size of the array element placement range in the radar unit is usually determined by the acceptable maximum size of the radar unit.

[0067] Specifically, Figure 1 In the illustrated embodiment, taking six transmitting and six receiving as an example, the interval d0 between the transmitting and receiving antenna arrays of radar unit 1 and radar unit 2 is placed at an interval greater than the range of placement of a single radar horizontal array. For a single radar unit 1 or radar unit 2, the range of placement of the transmitting and receiving antenna array is used as a constraint condition. When the array element spacing satisfies an integer multiple of half a wavelength, the transmitting antennas 7 of the four transmitting antennas 7 are placed at the four corner positions within the range as much as possible. The remaining transmitting antennas 7 are placed evenly and non-overlappingly on the connecting line of the four transmitting antennas 7, for example, the remaining two transmitting antennas 7 are placed at the midpoint of the upper and lower connecting lines. The four receiving antennas 8 are placed in sequence at the half-wavelength interval on the right side of the upper left and lower left transmitting antennas 7, the minimum interval above the lower right transmitting antenna 7, and the half-wavelength interval on the left side of the upper right transmitting antenna 7. The remaining two receiving antennas 8 are arranged at any position, as evenly as possible to ensure that the sparsity is not too high; the minimum interval depends on the size of a single antenna array element.

[0068] See also Figure 2 , Figure 2 A schematic diagram of array element arrangement of a transceiver antenna array and an equivalent virtual array 9 according to an embodiment of the present invention is shown.

[0069] The first radar unit 1 transceiver antenna array DP1 and the second radar unit 2 transceiver antenna array DP2 are placed on the same horizontal line with a spacing greater than the horizontal array placement range of a single radar (approximately equal to d0). The transmitting antenna array of the first radar unit 1 and the receiving antenna array of the second radar unit 2 are equivalent to Figure 2 In the CP1 virtual array 9, the transmitting antenna 7 of the second radar unit 2 and the receiving antenna 8 of the first radar unit 1 can be equivalent to Figure 2 CP2 virtual array 9; for the first radar unit 1 and the second radar unit 2 respectively adopt the same transmit and receive antenna array design as above, forming as follows Figure 2 The virtual array element CP1 in the arrangement shown in the middle completely overlaps with CP1.

[0070] Figure 2 In the figure, the first radar unit 1 and the second radar unit 2 are placed in the same way, CP1 and CP2 completely overlap, the horizontal apertures of the equivalent transceiver antenna arrays CP1 and CP2 are the same as the horizontal apertures of the transceiver antenna arrays DP1 and DP2, and the obtained four virtual arrays CP1, CP2, DP1, and DP2 together constitute the total horizontal aperture of the entire system, which is three times the horizontal aperture of a single radar (the horizontal aperture of a single radar is the horizontal aperture of the virtual array 9DP1 / 2), and at the same time maximizes the array aperture in the vertical direction, thereby obtaining an improvement in the angular resolution in the pitch and horizontal directions.

[0071] It can be seen that the present invention arranges each radar unit using the above-mentioned specific antenna array and arranges them at intervals larger than the horizontal array placement range of a single radar, and installs them in front of the vehicle body (such as Figure 3 As shown in the figure, it is possible to maximize the virtual aperture of a single radar unit, which is three times the horizontal aperture of a single radar, while maximizing the array aperture in the vertical direction, thereby improving the angular resolution in the pitch and horizontal directions.

[0072] The present invention also discloses a distributed radar system, see Figure 4 , Figure 4 The schematic diagram of the structure of a distributed radar system according to an embodiment of the present invention is shown. The distributed radar system comprises: the distributed radar device as described above in the present invention and a central control platform 3.

[0073] The distributed radar device includes: the first radar unit 1 and the second radar unit 2, which are used to transmit radar transmission signals and receive echo signals transmitted by the first radar unit and other radar units after being reflected by the target object. The echo signal includes the radar transmission signal and the radar reception signal. The first radar unit 1 and the second radar unit 2 communicate with the central control platform 3 via Ethernet. Figure 4 In the illustrated embodiment, both the radar unit and the central control platform 3 are provided with a high-speed Ethernet interface for realizing Ethernet communication; the first radar unit 1 is radar unit 1, and the second radar unit 2 is radar unit 2, and both also include a crystal oscillator, a radio frequency signal transmitting module, a radio frequency signal generating module, a radio frequency signal receiving module, a frequency mixing, an analog-to-digital conversion module, and an FFT operation module. When each radar unit receives a frame trigger signal, it sequentially transmits a radar transmission signal to the space through a crystal oscillator, a radio frequency signal generating module, a radio frequency signal transmitting module, and a transceiver antenna array, and receives the echo signal reflected by the target object emitted by itself and other radar units through the transceiver antenna array and the radio frequency signal receiving module. The echo signal is mixed, filtered, sampled by an ADC (analog-to-digital conversion module), and processed by a slow-time Fourier transform of the FFT operation module, and the processed echo signal data is sent to the central control platform 3 via Ethernet.

[0074] The central control platform 3 is used to generate and transmit through Ethernet through a frame trigger signal and trigger the first radar unit 1 and the second radar unit 2 to transmit a radar transmission signal, and to obtain the echo signals fed back by the first radar unit 1 and the second radar unit 2 and emitted by other radar units after being reflected by the target object; it is also used to perform channel separation on the echo signals of the radar transmission signals received by the first radar unit 1 and the second radar unit 2 themselves and the echo signals received by other radar units; and it is used to select the echo signals of the cross-channels in the echo signals, perform synchronous parameter estimation on the frequency and phase of the echo signals of the cross-channels to obtain a synchronous echo signal, and estimate the distance, speed and angle of the target object according to the synchronous echo signal.

[0075] Conventional radars cannot use echo signals from other radars (signals in CP1 and CP2) to estimate target parameters without frequency and phase synchronization. The present invention uses a central control platform 3, through channel separation and signal synchronization, to add cross channels, and realizes synchronous parameter estimation of the frequency and phase of the echo signals of the cross channels, realizes frequency and phase synchronization, performs parameter estimation on the frequency phase offset and then synchronously corrects it to obtain a synchronous echo signal, so that the central control platform 3 can use the echo signals of other radars (signals in CP1 and CP2), thereby realizing the joint processing of echo signals of different radar units, so that Figure 2 The middle virtual array 9 can be used for target object position monitoring.

[0076] The present invention is based on a distributed radar device with a specific array arrangement, obtains a synchronous echo signal through a central control platform 3, realizes radar positioning by using a virtual array 9 equivalent to a cross-channel, and improves the target detection rate and angular resolution of the system.

[0077] Figure 3 A distributed radar system installation diagram is shown. Figure 3 The present invention proposes a vehicle-mounted millimeter-wave coherent radar network consisting of two front-end radar units and a central control platform 3. The central control platform 3 realizes the synchronization of time, frequency and phase at the signal processing end through a software algorithm. The central control platform 3 sends a frame trigger signal for frame synchronization, thereby realizing signal coherent processing between distributed radar units without hardware connection.

[0078] In a further specific solution, the central control platform 3 includes: a channel separation module 5, a signal synchronization module 6 and an echo signal coherent processing module 4. The channel separation module 5 is used to separate the channels of the echo signals of the radar transmission signals received by the first radar unit 1 and the second radar unit 2 and the echo signals received by other radar units. Figure 4 In the embodiment shown, the channel separation module 5 divides the radar echo signal received by the radar unit into the self-channel DP1, the cross channel CP1, the self-channel DP2 and the cross channel CP2; the channel DP1 is the channel through which the radar unit 1 sends the radar transmission signal and receives the self-echo signal, and CP1 is the channel through which the radar unit 1 sends the radar transmission signal and the radar unit 2 receives the echo signal, which is used to equivalently output Figure 2 The CP1 virtual array 9 is shown in FIG. 1 . Channel DP2 is the channel through which radar unit 2 sends radar transmission signals and receives echo signals. CP2 is the channel through which radar unit 2 sends radar transmission signals and radar unit 1 receives echo signals, and is used to equivalently output Figure 2 The CP2 virtual array 9 is shown in FIG. The echo signals are transmitted to the echo signal coherent processing module 4 from the self-channel DP1, the cross-channel CP1, the self-channel DP2 and the cross-channel CP2.

[0079] The signal synchronization module 6 is used to select the echo signal of the cross channel in the echo signal, perform synchronization parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronized echo signal, and output it to the echo signal coherent processing module 4.

[0080] The echo signal coherent processing module 4 is used to estimate the distance, speed and angle of the target object according to the synchronous echo signal.

[0081] The present invention also discloses a distributed radar detection method, which is applied to the distributed radar system described in the present invention. Figure 5 , Figure 5 A schematic flow chart of a distributed radar detection method according to an embodiment of the present invention is shown.

[0082] The steps of the distributed radar detection method include:

[0083] S1: The central control platform generates a frame trigger signal and sends it to the first radar unit and the second radar unit.

[0084] S2: After receiving the frame trigger signal, the first radar unit and the second radar unit respectively transmit the transmitted radar transmission signal, and simultaneously receive the echo signal of their own radar transmission signal and the echo signal of other radar units, and feed back to the central control platform.

[0085] S3: The central control platform receives the echo signal and performs channel separation on the echo signals from the respective radar transmission signals received by the first radar unit and the second radar unit and the echo signals from other radar units.

[0086] S4: Select the echo signal in the cross channel, and perform synchronization parameter estimation on the frequency and phase of the echo signal in the cross channel to obtain a synchronized echo signal.

[0087] S5: Estimate the distance, speed and angle of the target object according to the synchronous echo signal.

[0088] In an optional solution, the channel separation module performs channel separation on the echo signals of the respective radar transmission signals received by the first radar unit and the second radar unit and the echo signals of other radar units. The signal synchronization module selects the echo signals of the cross-channels, performs synchronization parameter estimation on the frequency and phase of the echo signals of the cross-channels to obtain the synchronous echo signals, and outputs them to the echo signal coherent processing module. The echo signal coherent processing module estimates the distance, speed and angle of the target object based on the synchronous echo signals. This target parameter estimation method is the same as the traditional automotive radar processing method, and the present invention will not be repeated here.

[0089] In an optional solution, the signal synchronization module performs a step of synchronous parameter estimation on the frequency of the echo signal of the cross channel, specifically comprising: using radar q and radar p to represent the first radar unit and the second radar unit, or to represent the second radar unit and the first radar unit, respectively; and representing the radar transmission signal of radar q as:

[0090]

[0091] The radar receiving signal of radar p is expressed as:

[0092]

[0093] in is the flight time, that is, the time it takes for the radar signal to propagate in space from the time it is transmitted by radar q to the time it is received by radar p. is the frequency sweep slope of radar i (i=p,q);

[0094] For the echo signal of the cross channel: radar receiving signal s of radar p r,p (t), radar transmission signal s of radar q t,q (t), according to formula (1), the intermediate frequency signal s is obtained by mixing through the mixer IF,q,p (t):

[0095]

[0096] in,

[0097]

[0098] Δf 0，p，q =f 0，q-f 0，p , Δt j，p，q =t j，q -t j，p , ΔS p，q =S q -S p ;

[0099] Similarly, the intermediate frequency signal s transmitted by radar p and received by radar q is calculated IF,p，q (t).

[0100] The intermediate frequency signal s IF,p,q (t) According to formula (2), the frequency domain signal is obtained by two-dimensional Fourier transform:

[0101] X p，q，k (f r , f v )=2DFFT{s IF,p，q，k (t)} formula (2); where k is the radar receiving antenna index;

[0102] For the frequency domain signal s IF,p,q，k (t) According to equation (3), the signal Y transmitted by radar q and received by radar p is obtained by incoherent accumulation: p，q :

[0103]

[0104] At the same time, the intermediate frequency signal s IF,q,p,k (t) According to formula (4), the frequency domain signal is obtained by two-dimensional Fourier transform:

[0105] X q,p,k (f r , f v )=2DFFT{s IF,q,p,k (t)} formula (4);

[0106] For the frequency domain signal s IF,q,p,k (t) According to equation (4), the signal Y transmitted by radar p and received by radar q is obtained by incoherent accumulation: p，p ;

[0107]

[0108] Radar q transmits the signal Y that radar p receives p，q Radar p transmits signal Y which is received by radar q q，p , and do the correlation according to formula (5):

[0109]

[0110] The frequency offset is calculated according to formula (6):

[0111]

[0112] For signal X p，q，k and signal X q,p,,k Frequency shift and Complete frequency synchronization.

[0113] In order to coherently use the entire radar network for arrival angle estimation, it is necessary to perform parameter estimation on the phase difference Y between the subarrays. The method by which the signal synchronization module performs synchronization parameter estimation on the frequency of the echo signal of the cross channel to obtain the synchronized echo signal is similar to frequency synchronization. The signal synchronization module is completed using redundant virtual channels with overlapping equivalent spatial positions. Specifically, for signals in redundant virtual channels in different subarrays, the flight time is equal. The phase difference of the received signal in the redundant virtual channels different from the subarray can be compared with the phase offset between the estimated subapertures, and then the phase offset can be compensated to each subarray, thereby achieving phase synchronization. After the frequency and phase are synchronized, the synchronized echo signal can be obtained.

[0114] At present, vehicle-mounted radars can only establish coherence by connecting coaxial cables or other wiring harnesses between different radar units to share local oscillator signals or clock signals. The frequency phase synchronization parameter estimation scheme proposed in the present invention can establish coherence through signal processing means without wiring harness connection. After synchronization, the echo data from different radars can be jointly input into the traditional angle measurement module for angle measurement (the traditional solution can be used for angle measurement).

[0115] The invention also discloses a car of the invention, comprising the distributed radar system of the invention.

[0116] The present invention also discloses a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the distributed radar detection method according to the present invention are implemented.

[0117] The present invention also discloses an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps of the distributed radar detection method described in the present invention are implemented.

[0118] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A distributed radar device, comprising: The first radar unit and the second radar unit are characterized in that: The transceiver antenna array in the first radar unit and the transceiver antenna array in the second radar unit are placed on the same horizontal line at a distance greater than the horizontal array placement range of a single radar; The transceiver antenna array in the first radar unit and the transceiver antenna array in the second radar unit both include: a transmitting antenna array and a receiving antenna array; The transmitting antenna array comprises: a plurality of transmitting antennas located at four vertex positions within the array placement range, and a plurality of evenly arranged transmitting antennas located on a horizontal connection line of the vertex transmitting antennas; The receiving antenna array includes: starting from the transmitting antenna at the first vertex position on the upper left, receiving antennas are arranged in sequence in a counterclockwise direction at the right half-wavelength interval, the right half-wavelength interval, the upper minimum interval and the left half-wavelength interval of the corresponding vertex position transmitting antenna, and other uniformly arranged receiving antennas; the minimum interval is the size of a single array element.

2. The distributed radar device according to claim 1, characterized in that: The transmitting antenna at the vertex position is arranged at the maximum size position of the array element placement range in the radar unit, and the interval between the vertex array elements meets the integer multiple of half the wavelength.

3. A distributed radar system, It is characterized in that The method comprises: a distributed radar device as claimed in claim 1 or 2; the distributed radar device comprises: a first radar unit and a second radar unit, which are used to transmit radar transmission signals respectively, and receive echo signals transmitted by the first radar unit and other radar units after being reflected by target objects; The distributed radar system further comprises: Central control platform; used to generate and trigger the first radar unit and the second radar unit to transmit radar transmission signals through frame trigger signals, and to obtain echo signals fed back by the first radar unit and the second radar unit and transmitted by themselves and other radar units after being reflected by the target object; It is also used to perform channel separation on the echo signals of the radar transmission signals received by the first radar unit and the second radar unit and the echo signals received by other radar units; And it is used to select the echo signal of the cross channel, perform synchronous parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronous echo signal, and estimate the distance, speed and angle of the target object according to the synchronous echo signal.

4. The distributed radar system according to claim 3, characterized in that: The central control platform includes: a channel separation module, a signal synchronization module and an echo signal coherent processing module; The channel separation module is used to perform channel separation on the echo signals of the radar transmission signals received by the first radar unit and the second radar unit and the echo signals received by other radar units; The signal synchronization module is used to select the echo signal of the cross channel, perform synchronization parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronized echo signal, and output it to the echo signal coherent processing module; The echo signal coherent processing module is used to estimate the distance, speed and angle of the target object according to the synchronous echo signal.

5. A car, characterized in that: Comprising a distributed radar system as claimed in claim 3 or 4.

6. A distributed radar detection method, characterized in that: Applied to the distributed radar system of claim 3 or 4, the method comprising: The central control platform generates a frame trigger signal and sends it to the first radar unit and the second radar unit; After receiving the frame trigger signal, the first radar unit and the second radar unit respectively transmit the transmitting radar transmission signal, and simultaneously receive the echo signal of their own radar transmission signal and the echo signal of other radar units, and feed back to the central control platform; The central control platform receives the echo signal and performs channel separation on the echo signal from the respective radar transmission signals received by the first radar unit and the second radar unit and the echo signal received by other radar units; Selecting the echo signal in the cross channel, performing synchronization parameter estimation on the frequency and phase of the echo signal in the cross channel to obtain a synchronous echo signal; And the distance, speed and angle of the target object are estimated according to the synchronous echo signal.

7. The distributed radar detection method according to claim 6, characterized in that: The channel separation module performs channel separation on the echo signals of the radar transmission signals received by the first radar unit and the second radar unit and the echo signals of other radar units; The signal synchronization module selects the echo signal of the cross channel, performs synchronization parameter estimation on the frequency and phase of the echo signal of the cross channel to obtain a synchronized echo signal, and outputs the synchronized echo signal to the echo signal coherent processing module; The echo signal coherent processing module estimates the distance, speed and angle of the target object according to the synchronous echo signal.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the distributed radar detection method according to claim 6 or 7 are implemented.

9. An electronic device, characterized in that: It includes a memory and a processor, wherein the memory stores a computer program, and when the processor calls the computer program in the memory, the steps of the distributed radar detection method as described in 6 or 7 are implemented.

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