WO2021240810A1 - Dispositif radar et procédé de traitement de signaux radar - Google Patents

Dispositif radar et procédé de traitement de signaux radar Download PDF

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Publication number
WO2021240810A1
WO2021240810A1 PCT/JP2020/021447 JP2020021447W WO2021240810A1 WO 2021240810 A1 WO2021240810 A1 WO 2021240810A1 JP 2020021447 W JP2020021447 W JP 2020021447W WO 2021240810 A1 WO2021240810 A1 WO 2021240810A1
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Prior art keywords
integration
signal
unit
antennas
radar
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PCT/JP2020/021447
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English (en)
Japanese (ja)
Inventor
聡 影目
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三菱電機株式会社
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Priority to JP2022527465A priority Critical patent/JP7109710B2/ja
Priority to PCT/JP2020/021447 priority patent/WO2021240810A1/fr
Publication of WO2021240810A1 publication Critical patent/WO2021240810A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/42—Simultaneous measurement of distance and other co-ordinates
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00

Definitions

  • This disclosure relates to a radar device and a radar signal processing method.
  • Patent Document 1 discloses a radar device using a plurality of transmitting antennas and a plurality of receiving antennas.
  • a plurality of transmitting antennas and a plurality of receiving antennas are arranged so as to be orthogonal to each other. As a result, the antenna opening is expanded in the horizontal direction and the antenna opening is expanded in the vertical direction.
  • the antenna aperture length in a radar device is proportional to the angular resolution of the radar device. Therefore, by using a plurality of antennas, the angular resolution of the radar device can be improved.
  • the angle value corresponding to the target differs for each antenna. That is, a state occurs in which the target is located in the near field with respect to a plurality of antennas. This makes it difficult to integrate for angle measurement, and there is a problem that the amount of calculation for angle measurement increases.
  • the present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to reduce the amount of calculation for angle measurement in a radar device using a plurality of antennas.
  • the radar device is a radar device including a plurality of antennas including one or more transmitting antennas and a plurality of receiving antennas, and a radar signal processing device, wherein the radar signal processing device is a plurality of radar devices.
  • the integral unit calculation unit that sets a plurality of integral groups by grouping the receiving antennas of the above, and the first coherent integral for the signals in the integral group corresponding to each of the plurality of integral groups.
  • the first integral unit that generates a plurality of first integral signals corresponding to each of the integral groups of the above, and the second integral unit that generates the second integral signal by executing the second coherent integral for the plurality of first integral signals. It includes an integration unit and an angle calculation unit that calculates an angle value corresponding to each target candidate using a second integration signal.
  • the integration for angle measurement can be facilitated.
  • the amount of calculation for angle measurement can be reduced.
  • FIG. 1 It is a block diagram which shows the main part of the radar apparatus which concerns on Embodiment 1.
  • FIG. It is a block diagram which shows the main part of the 1st antenna module in the radar apparatus which concerns on Embodiment 1.
  • FIG. It is a block diagram which shows the main part of the 1st signal processor in the radar apparatus which concerns on Embodiment 1.
  • FIG. It is a block diagram which shows the hardware composition of the main part of the 1st signal processor in the radar apparatus which concerns on Embodiment 1.
  • FIG. It is a block diagram which shows the other hardware composition of the main part of the 1st signal processor in the radar apparatus which concerns on Embodiment 1.
  • FIG. It is a flowchart which shows the operation of the 1st signal processor in the radar apparatus which concerns on Embodiment 1.
  • FIG. It is explanatory drawing which shows the example of the distance bin number corresponding to a plurality of distance speed signals, the distance bin number corresponding to each distance speed signal, and the speed bin number corresponding to each distance speed signal.
  • It is explanatory drawing which shows the example of the incoherent integration signal, the distance bin number corresponding to an incoherent integration signal, and the velocity bin number corresponding to an incoherent integration signal.
  • FIG. It is a block diagram which shows the main part of the 1st signal processor and the 2nd signal processor in the radar apparatus which concerns on Embodiment 2.
  • FIG. It is explanatory drawing which shows the example of the plurality of integration groups corresponding one-to-one with a plurality of antenna modules. It is explanatory drawing which shows the example of the state in which a plurality of antennas are virtually arranged at equal intervals, while showing the example of the plurality of antenna arrangement intervals which are different from each other. It is explanatory drawing which shows the example of the state which the grating level exceeds a desired level. It is explanatory drawing which shows the example of the state which suppressed the grating level to a desired level or less.
  • FIG. 2nd signal processor It is a block diagram which shows the hardware composition of the main part of the 2nd signal processor in the radar apparatus which concerns on Embodiment 2.
  • FIG. 2nd signal processor It is a block diagram which shows the other hardware composition of the main part of the 2nd signal processor in the radar apparatus which concerns on Embodiment 2.
  • FIG. 2nd signal processor It is a block diagram which shows the other hardware composition of the main part of the 2nd signal processor in the radar apparatus which concerns on Embodiment 2.
  • FIG. 1 is a block diagram showing a main part of the radar device according to the first embodiment.
  • FIG. 2 is a block diagram showing a main part of the first antenna module in the radar device according to the first embodiment.
  • FIG. 3 is a block diagram showing a main part of the first signal processor in the radar device according to the first embodiment. The radar device according to the first embodiment will be described with reference to FIGS. 1 to 3.
  • the radar device 1 includes a plurality of antenna groups. Each antenna group includes one or more antennas. More specifically, the plurality of antenna groups include one or more transmitting antenna groups and one or more receiving antenna groups. Each transmitting antenna group includes one or more transmitting antennas. Each receiving antenna group includes a plurality of receiving antennas.
  • the radar device 1 includes one or more antenna modules. Each antenna group is provided in one of the corresponding antenna modules out of one or more antenna modules.
  • each antenna module includes at least one transmitting antenna group and at least one receiving antenna group.
  • each antenna module comprises at least one receiving antenna group.
  • each antenna module comprises at least one transmit antenna group.
  • an antenna module including at least one transmitting antenna group and at least one receiving antenna group may be referred to as a "first antenna module”. Further, an antenna module including at least one receiving antenna group may be referred to as a "second antenna module”. Further, an antenna module including at least one transmitting antenna group may be referred to as a "third antenna module”.
  • the individual antenna modules are provided in the vehicle, for example. More specifically, the individual antenna modules are provided, for example, on the edge of the front window of the vehicle, the edge of the rear window of the vehicle, the pillars of the vehicle, the front bumper of the vehicle or the rear bumper of the vehicle. ing.
  • the radar device 1 includes a first antenna module 2_1, a first signal processor 3_1, and a display 4.
  • the first antenna module 2_1 includes a transmitting unit 5 and a first receiving unit 6_1.
  • the first signal processor 3_1 constitutes the main part of the radar signal processor 7.
  • the transmission unit 5 includes a local oscillation signal generation unit 11, a code modulation unit 12, a plurality of transmitters 13, and a plurality of transmission antennas 14.
  • the transmitting antenna group 15 is composed of a plurality of transmitting antennas 14.
  • the first receiving unit 6_1 includes a plurality of receiving antennas 21, a plurality of receivers 22, and a plurality of analog-to-digital converters (hereinafter referred to as “A / D converters”) 23.
  • the receiving antenna group 24 is composed of a plurality of receiving antennas 21.
  • NTx indicates the number of transmission channels (hereinafter referred to as “the number of transmission channels”).
  • the number of transmission channels NTx corresponds to the number of transmission antennas 14. That is, the number of transmission channels NTx corresponds to the number of transmitters 13.
  • the number n Tx indicating each transmission channel may be referred to as a “transmission channel number”.
  • NRx indicates the number of receiving channels (hereinafter referred to as “number of receiving channels”).
  • the number of receiving channels N Rx corresponds to the number of receiving antennas 21. That is, the number of receiving channels N Rx corresponds to the number of receivers 22 and corresponds to the number of A / D converters 23.
  • the number n Rx indicating each receiving channel may be referred to as a “receiving channel number”.
  • the RF (Radio Frequency) signal transmitted by the individual transmitting antenna 14 or the RF signal transmitted by the individual transmitting antenna 14 is collectively referred to as “transmission RF signal” or “transmission signal”.
  • transmission RF signal the RF signal received by each receiving antenna 21
  • reflected RF signal the RF signal received by each receiving antenna 21
  • received RF signal the RF signal received by each receiving antenna 21
  • the local oscillation signal generation unit 11 generates a local oscillation signal.
  • the local oscillation signal generation unit 11 outputs the generated local oscillation signal to the code modulation unit 12. Further, the local oscillation signal generation unit 11 outputs the generated local oscillation signal to each receiver 22.
  • the local oscillation signal generation unit 11 is configured by, for example, a dedicated circuit.
  • the code modulation unit 12 acquires the local oscillation signal output by the local oscillation signal generation unit 11.
  • the code modulation unit 12 executes code modulation for the acquired locally oscillated signal. This produces a transmit RF signal corresponding to each transmit channel.
  • the code modulation unit 12 outputs the generated transmission RF signal to the corresponding transmitter 13.
  • the code modulation unit 12 is composed of, for example, a dedicated circuit.
  • the individual transmitter 13 acquires the transmission RF signal output by the code modulation unit 12.
  • the individual transmitter 13 outputs the acquired transmission RF signal to the corresponding transmission antenna 14.
  • the individual transmitting antenna 14 receives the input of the transmitting RF signal output by the corresponding transmitter 13. Each transmitting antenna 14 radiates the input transmitted RF signal into space.
  • the transmitted RF signal radiated by the individual transmitting antennas 14 is reflected by the target. This produces a reflected RF signal.
  • the generated reflected RF signal is incident on each receiving antenna 21.
  • the individual receiving antennas 21 output the received RF signal corresponding to the incident reflected RF signal to the corresponding receiver 22.
  • Each receiver 22 acquires the local oscillation signal output by the local oscillation signal generation unit 11. Further, each receiver 22 acquires the received RF signal output by the corresponding receiving antenna 21. Each receiver 22 uses the acquired local oscillation signal and the acquired received RF signal to generate a beat signal corresponding to the corresponding receiving channel. Each receiver 22 outputs the generated beat signal to the corresponding A / D converter 23.
  • the beat signal corresponding to each receive channel includes a component corresponding to NTx transmission channels (that is, a component corresponding to NTx transmission RF signals).
  • the beat signal corresponding to each received channel is referred to as a “received beat signal”.
  • the received RF signal or the received beat signal may be collectively referred to as a “received signal”.
  • the individual A / D converter 23 acquires the received beat signal output by the corresponding receiver 22.
  • the individual A / D converter 23 converts the acquired received beat signal from an analog signal to a digital signal.
  • Each A / D converter 23 outputs the converted received beat signal to the first signal processor 3_1.
  • the first signal processor 3_1 includes a separation unit 31, a signal generation unit 32, an incoherent integration unit 33, a target candidate detection unit 34, an integration unit calculation unit 35, a first integration unit 36, and a second integration unit. It has a unit 37 and an angle calculation unit 38.
  • the integration unit calculation unit 35, the first integration unit 36, and the second integration unit 37 constitute the main part of the coherent integration unit 39.
  • the separation unit 31 acquires the received beat signal output by each A / D converter 23.
  • the separation unit 31 demodulates the acquired received beat signal.
  • the demodulated received beat signal is separated into signals corresponding to individual transmission channels and separated into signals corresponding to individual reception channels.
  • the separation unit 31 outputs the demodulated received beat signal to the signal generation unit 32.
  • the signal generation unit 32 acquires the received beat signal output by the separation unit 31.
  • the signal generation unit 32 executes a discrete Fourier transform on the acquired received beat signal.
  • a signal corresponding to the distance of each target candidate and the speed of each target candidate (hereinafter referred to as “distance speed signal”) is generated for each transmission channel and each reception channel.
  • the signal generation unit 32 outputs the generated distance velocity signal to the incoherent integration unit 33.
  • the incoherent integration unit 33 acquires the distance velocity signal output by the signal generation unit 32.
  • the incoherent integration unit 33 executes incoherent integration on the acquired distance velocity signal.
  • the incoherent integration unit 33 outputs a signal generated by executing such incoherent integration (hereinafter referred to as “incoherent integration signal”) to the target candidate detection unit 34.
  • the target candidate detection unit 34 acquires the incoherent integration signal output by the incoherent integration unit 33.
  • the target candidate detection unit 34 uses the acquired incoherent integration signal to calculate the distance value corresponding to each target candidate and the speed value corresponding to each target candidate. As a result, individual target candidates are detected.
  • the target candidate detection unit 34 specifies a distance speed signal corresponding to each target candidate, a speed bin number corresponding to each target candidate, and a distance bin number corresponding to each target candidate.
  • the speed bin number indicates a sampling number in the speed direction.
  • the distance bin number indicates a sampling number in the distance direction.
  • the target candidate detection unit 34 outputs the specified distance velocity signal, the specified velocity bin number, and the specified distance bin number to the coherent integration unit 39.
  • the integration unit calculation unit 35 sets a plurality of groups for integration (hereinafter referred to as "integration group” or “integration unit”) by grouping a plurality of receiving antennas 21. At this time, the integration unit calculation unit 35 sets a plurality of integration groups so that each target candidate is approximated to be located in a distant field with respect to each integration group.
  • the first integration unit 36 executes coherent integration (hereinafter referred to as “first coherent integration”) for a signal corresponding to each integration group (hereinafter referred to as “integration group signal”) for each target candidate.
  • first coherent integration coherent integration
  • integration group signal a signal corresponding to each integration group
  • the first integration unit 36 outputs a signal generated by executing the first coherent integration (hereinafter referred to as “first integration signal”) to the second integration unit 37. That is, the first integration unit 36 outputs the first integration signal corresponding to each integration group to the second integration unit 37.
  • first integration signal a signal generated by executing the first coherent integration
  • the second integration unit 37 acquires the first integration signal output by the first integration unit 36.
  • the second integration unit 37 executes coherent integration (hereinafter referred to as “second coherent integration”) with respect to the acquired second integration signal for each target candidate.
  • the second integration unit 37 outputs a signal (hereinafter referred to as “second integration signal”) generated by executing the second coherent integration to the angle calculation unit 38.
  • the angle calculation unit 38 acquires the second integration signal output by the second integration unit 37.
  • the angle calculation unit 38 calculates the angle value corresponding to each target candidate by using the acquired second integral signal.
  • Each angle value indicates the azimuth angle of the corresponding target candidate.
  • the display 4 acquires the distance value calculated by the target candidate detection unit 34, the speed value calculated by the target candidate detection unit 34, and the angle value calculated by the angle calculation unit 38. The display 4 displays these values.
  • the processes executed by the separation unit 31 may be collectively referred to as “separation processing”.
  • the processing executed by the signal generation unit 32 may be generically referred to as “signal generation processing”.
  • the processing executed by the incoherent integration unit 33 may be collectively referred to as “incoherent integration processing”.
  • the processes executed by the target candidate detection unit 34 may be collectively referred to as “target candidate detection process”.
  • the processes executed by the integral unit calculation unit 35 may be collectively referred to as “integral unit calculation process”.
  • the processes executed by the first integral unit 36 may be collectively referred to as "first integral process”.
  • the processes executed by the second integral unit 37 may be collectively referred to as "second integral process”.
  • the processes executed by the angle calculation unit 38 may be collectively referred to as "angle calculation process”.
  • the functions of the separation unit 31 may be collectively referred to as "separation function".
  • the functions of the signal generation unit 32 may be collectively referred to as a "signal generation function”.
  • the functions of the incoherent integration unit 33 may be collectively referred to as “incoherent integration function”.
  • the functions of the target candidate detection unit 34 may be collectively referred to as “target candidate detection function”.
  • the functions of the integration unit calculation unit 35 may be collectively referred to as "integration unit calculation function”.
  • the functions of the first integration unit 36 may be collectively referred to as the "first integration function”.
  • the functions of the second integration unit 37 may be collectively referred to as “second integration function”.
  • the functions of the angle calculation unit 38 may be collectively referred to as an "angle calculation function”.
  • the code of "F1” may be used for the separation function.
  • the code of "F2” may be used for the signal generation function.
  • the code of "F3” may be used for the incoherent integration function.
  • the code of "F4" may be used for the target candidate detection function.
  • the code of "F5" may be used for the integration unit calculation function.
  • the code of "F6” may be used for the first integration function.
  • the code of "F7” may be used for the second integration function.
  • the code of "F8” may be used for the angle calculation function.
  • the first signal processor 3_1 has a processor 41 and a memory 42.
  • the memory 42 includes a plurality of functions (including a separation function, a signal generation function, an incoherent integration function, a target candidate detection function, an integration unit calculation function, a first integration function, a second integration function, and an angle calculation function) F1.
  • the program corresponding to ⁇ F8 is stored.
  • the processor 41 reads and executes the program stored in the memory 42. As a result, a plurality of functions F1 to F8 are realized.
  • the first signal processor 3_1 has a processing circuit 43.
  • the processing circuit 43 executes processing corresponding to a plurality of functions F1 to F8. As a result, a plurality of functions F1 to F8 are realized.
  • the first signal processor 3_1 has a processor 41, a memory 42, and a processing circuit 43.
  • a program corresponding to a part of the plurality of functions F1 to F8 is stored in the memory 42.
  • the processor 41 reads and executes the program stored in the memory 42. As a result, some of these functions are realized.
  • the processing circuit 43 executes processing corresponding to the remaining functions of the plurality of functions F1 to F8. As a result, such residual functions are realized.
  • the processor 41 is composed of one or more processors.
  • a CPU Central Processing Unit
  • a GPU Graphics Processing Unit
  • a microprocessor a microprocessor
  • a microprocessor a microprocessor
  • a DSP Digital Signal Processor
  • the memory 42 is composed of one or more non-volatile memories.
  • the memory 42 is composed of one or more non-volatile memories and one or more volatile memories. That is, the memory 42 is composed of one or more memories.
  • the individual memory uses, for example, a semiconductor memory, a magnetic disk, an optical disk, a magneto-optical disk, a magnetic tape, or a magnetic drum. More specifically, each volatile memory uses, for example, a RAM (Random Access Memory).
  • the individual non-volatile memories include, for example, a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electricularly Erasable Digital Memory), a flexible drive disk, a drive disk A compact disc, a DVD (Digital Versaille Disc), a Blu-ray disc, or a mini disc is used.
  • the processing circuit 43 is composed of one or more digital circuits.
  • the processing circuit 43 is composed of one or more digital circuits and one or more analog circuits. That is, the processing circuit 43 is composed of one or more processing circuits.
  • the individual processing circuits are, for example, ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), FPGA (Field Programmable Gate Array), System LSI (Sy), and System (Sy). Is.
  • the processor 41 when the processor 41 is composed of a plurality of processors, the correspondence between the plurality of functions F1 to F8 and the plurality of processors is arbitrary. That is, each of the plurality of processors may read and execute a program corresponding to one or more corresponding functions among the plurality of functions F1 to F8.
  • the processor 41 may include a dedicated processor corresponding to each of the plurality of functions F1 to F8.
  • each of the plurality of memories may store a program corresponding to one or more corresponding functions among the plurality of functions F1 to F8.
  • the memory 42 may include a dedicated memory corresponding to each of the plurality of functions F1 to F8.
  • the processing circuit 43 when the processing circuit 43 is composed of a plurality of processing circuits, the correspondence between the plurality of functions F1 to F8 and the plurality of processing circuits is arbitrary. That is, each of the plurality of processing circuits may execute processing corresponding to one or more corresponding functions among the plurality of functions F1 to F8.
  • the processing circuit 43 may include a dedicated processing circuit corresponding to each of the plurality of functions F1 to F8.
  • the separation unit 31 executes the separation process (step ST1).
  • the signal generation unit 32 executes the signal generation process (step ST2).
  • the incoherent integration unit 33 executes the incoherent integration process (step ST3).
  • the target candidate detection unit 34 executes the target candidate detection process (step ST4).
  • the integration unit calculation unit 35 executes the integration unit calculation process (step ST5).
  • the first integration unit 36 executes the first integration process (step ST6).
  • the second integration unit 37 executes the second integration process (step ST7).
  • the angle calculation unit 38 executes the angle calculation process (step ST8).
  • any element in an arbitrary formula is described in a sentence, the element is described in a non-italic type regardless of whether the typeface of the element in the formula is italic. Further, regardless of whether or not the typeface of the element in the mathematical formula is bold, the element is described in non-bold type. This is mainly due to the request for electronic filing. For the typeface of each element, the typeface in the mathematical formula is correct.
  • the local oscillation signal generation unit 11 generates the local oscillation signal L 1 (h, t).
  • the local oscillation signal generation unit 11 outputs the generated local oscillation signal L 1 (h, t) to the code modulation unit 12, and receives the generated local oscillation signal L 1 (h, t) individually. Output to the machine 22.
  • the local oscillation signal L 1 (h, t) is expressed by the following equation (1).
  • j is an imaginary unit.
  • phi 0 is an initial phase of the local oscillation signal.
  • h is a hit number.
  • H is the number of hits.
  • AL is the amplitude of the locally oscillated signal.
  • f 0 is the transmission frequency of the transmission RF signal.
  • B 0 is a modulation band of the transmission RF signal.
  • T 0 is the modulation time.
  • t is time.
  • T chp is a transmission repetition cycle of the transmission RF signal corresponding to the transmission channel number n Tx.
  • T chp is expressed by the following equation (2).
  • TTx is a transmission repetition period.
  • TTx is expressed by the following equation (3).
  • T 1 is the time until the next modulation is executed.
  • the code modulation unit 12 acquires the local oscillation signal L 1 (h, t) output by the local oscillation signal generation unit 11.
  • the code modulation unit 12 executes code modulation for the acquired local oscillation signal L 1 (h, t).
  • the code modulation unit 12 adds a modulation code to the acquired local oscillation signal L 1 (h, t), whereby the transmission RF signal Tx (n Tx , h, t) corresponding to each transmission channel is added. ) Is generated.
  • the local oscillation signal L 1 (h, t) corresponding to each transmission channel is code-modulated. This makes it possible to improve the orthogonality of the radio waves transmitted by the individual transmitting antennas 14. As a result, it is possible to facilitate the separation of the signals corresponding to the individual transmission channels. In addition, it is possible to suppress the occurrence of interference between transmission channels and the occurrence of interference with the radar device 1 due to external radio waves.
  • the code modulation unit 12 cyclically shifts the cyclic code C 0 (h) with the cyclic shift amount ⁇ h (n Tx ) according to the following equation (4).
  • the cyclic code C 0 (h) is preset.
  • the cyclic shift amount ⁇ h (n Tx ) is set for each transmission channel.
  • the modulation code Code 1 (n Tx , h) corresponding to each transmission channel is generated.
  • the cyclic code C 0 (h) an M sequence (Maximal Sequence Sequence), a Gold sequence, or a scissors sequence may be used.
  • the code modulation unit 12 uses the local oscillation signal L 1 (h, t) and the modulation code Code 1 (n Tx , h) according to the following equation (5) to correspond to the transmission RF corresponding to each transmission channel. Generate a signal Tx (n Tx , h, t).
  • the code modulation unit 12 outputs the generated transmission RF signal Tx (n Tx , h, t) to the corresponding transmitter 13.
  • Each transmitter 13 acquires the transmission RF signal Tx (n Tx , h, t) output by the code modulation unit 12. Each transmitter 13 outputs the acquired transmission RF signal Tx (n Tx , h, t) to the corresponding transmission antenna 14.
  • Each transmitting antenna 14 receives an input of a transmitting RF signal Tx (n Tx , h, t) output by the corresponding transmitter 13. Each transmitting antenna 14 radiates the input transmission RF signal Tx (n Tx , h, t) into space.
  • ⁇ Receiving antenna 21 The transmit RF signal Tx (n Tx , h, t) radiated by the individual transmit antennas 14 is reflected by the target. This produces a reflected RF signal. The generated reflected RF signal is incident on each receiving antenna 21. Each receiving antenna 21 outputs the received RF signal Rx 1 (n Rx , h, t) corresponding to the incident reflected RF signal to the corresponding receiver 22.
  • the received RF signal Rx 1 (n Rx , h, t) is expressed by the following equation (6).
  • the received RF signal Rx 1 (n Rx , h, t) corresponding to each receiving channel is N Tx reflected RF signals Rx 0 (n Tx , n Rx , h, t). It is represented by the sum of.
  • the N Tx reflected RF signals Rx 0 (n Tx , n Rx , h, t) correspond to the N Tx transmission channels, respectively.
  • the reflected RF signal Rx 0 (n Tx , n Rx , h, t) corresponding to each transmission channel is expressed by the following equation (7).
  • a R is the amplitude of the received RF signal.
  • R Tx (n Tx , h, t) is the distance between each transmit channel and the target.
  • R Rx (n Rx , h, t) is the distance between each receive channel and the target.
  • c is the speed of light.
  • t' is the time within one hit.
  • Each receiver 22 acquires the local oscillation signal L 1 (h, t) output by the local oscillation signal generation unit 11. Further, each receiver 22 acquires the received RF signal Rx 1 (n Rx , h, t) output by the corresponding receiving antenna 21.
  • Each receiver 22 down-converts the acquired received RF signal Rx 1 (n Rx , h, t) using the acquired local oscillation signal L 1 (h, t). The individual receivers 22 then use a band filter to filter the down-converted signal. The individual receivers 22 then amplify the strength of the filtered signal. The individual receivers 22 then use the amplified signal to perform phase detection.
  • the reception beat signal V '1 corresponding to the receiving channel corresponding (n Rx, h, t) is generated. That is, in the N Rx number of receivers 22, N Rx number of receiving the beat signal V '1 corresponding to N Rx number of receiving channels (n Rx, h, t) is generated.
  • Received beat signal V '1 (, n Rx, h t) corresponding to each of the receiving channels is represented by the following equation (13).
  • a V is the amplitude of the received beat signal V '1 (n Rx, h , t).
  • received corresponding to each reception channel beat signal V '1 (n Rx, h , t) is, N Tx number of receiving the beat signal V' 0 (n Tx, n Rx, h, It is represented by the sum of t).
  • N Tx number of receiving the beat signal V '0 (n Tx, n Rx, h, t) respectively correspond to the N Tx number of transmission channels.
  • Received beat signal V '0 corresponding to the individual transmission channels (n Tx, n Rx, h , t) is expressed by the following equation (14).
  • Individual receiver 22 outputs thus received beat signal generated by V '1 (n Rx, h , t) to the corresponding A / D converter 23 a.
  • ⁇ A / D converter 23 Individual A / D converter 23, the corresponding received output by the receiver 22 beat signal V '1 (n Rx, h , t) to obtain a. Individual A / D converter 23 converts the received beat signal is the acquired V '1 (n Rx, h , t) to a digital signal from an analog signal. As a result, the received beat signal V 1 (n Rx , h, m) represented by the following equation (15) is generated.
  • the received beat signal V 1 (n Rx , h, m) represented by the equation (15) corresponds to each received channel.
  • receiving the beat signal corresponding to the individual receiving channel V 1 (n Rx, h, m) is, N Tx number of receiving the beat signal V 0 (n Tx, n Rx , h, m) It is represented by the sum of.
  • N Tx of received beat signals V 0 (n Tx , n Rx , h, m) correspond to N T x of transmission channels, respectively.
  • the received beat signal V 0 (n Tx , n Rx , h, m) corresponding to each transmission channel is expressed by the following equation (16).
  • ⁇ t is the sampling interval within the modulation time T 0.
  • m is the sampling number of the received beat signal is sampled at the modulation time T within 0.
  • M is the number of samples received beat signal within the modulation time T 0.
  • the terms including ⁇ t 2 and 1 / c 2 are expressed approximately.
  • Each A / D converter 23 outputs the received beat signal V 1 (n Rx , h, m) thus generated to the first signal processor 3_1.
  • ⁇ Separation unit 31 (step ST1)> The separation unit 31 acquires the received beat signal V 1 (n Rx , h, m) output by each A / D converter 23. The separation unit 31 demodulates the acquired received beat signal V 1 (n Rx , h, m) using the modulation code Code 1 (n Tx, h) corresponding to each transmission channel. That is, the separation unit 31 demodulates the acquired received beat signal V 1 (n Rx , h, m) by the following equation (17).
  • the received beat signals V 1, C (n Tx , n Rx , h, m) after demodulation are generated.
  • the received beat signals V 1, C (n Tx , n Rx , h, m) after demodulation correspond to individual transmission channels and correspond to individual reception channels.
  • the demodulated received beat signals V 1, C (n Tx , n Rx , h, m) are separated into signals corresponding to the individual transmission channels and correspond to the individual reception channels. Separated into signals.
  • the separation unit 31 outputs the demodulated received beat signals V 1, C (n Tx , n Rx , h, m) to the signal generation unit 32.
  • ⁇ Signal generation unit 32 (step ST2)>
  • the signal generation unit 32 acquires the received beat signals V 1, C (n Tx , n Rx , h, m) after demodulation.
  • the signal generation unit 32 executes a discrete Fourier transform on the acquired received beat signals V 1, C (n Tx , n Rx, h, m). Specifically, for example, the signal generation unit 32 executes the discrete Fourier transform according to the following equation (20).
  • a distance velocity signal f b, 1 (n Tx , n Rx , q, k) is generated.
  • the distance velocity signals f b, 1 (n Tx , n Rx , q, k) correspond to individual transmission channels and correspond to individual reception channels.
  • a distance velocity signal f b, 1 (n Tx , n Rx , q, k) is generated for each transmission channel and each reception channel.
  • q is a speed bin number.
  • k is a distance bin number.
  • the discrete Fourier transform is executed for each sampling number m and for each hit number h, so that the distance velocity signals f b, 1 (n Tx , n Rx , q, k) corresponding to the individual target candidates are executed. ) Is generated.
  • the target candidate detection unit 34 which will be described later, can calculate the distance value corresponding to each target candidate and the speed value corresponding to each target candidate.
  • the signal-to-noise ratio (Signal to Noise Ratio, SNR) is improved according to the 10 log 10 (HM). As a result, the target detection capability of the radar device 1 can be improved.
  • the signal generation unit 32 may use a fast Fourier transform (FFT) instead of the discrete Fourier transform.
  • FFT fast Fourier transform
  • the amount of calculation in the signal generation unit 32 can be reduced.
  • the processing speed of the signal generation unit 32 can be increased. As a result, the cost of the radar device 1 can be reduced, and the processing time of the radar signal processing device 7 can be shortened.
  • the signal generation unit 32 outputs the distance velocity signals f b, 1 (n Tx , n Rx , q, k) thus generated to the incoherent integration unit 33.
  • the incoherent integration unit 33 acquires the distance velocity signals f b, 1 (n Tx , n Rx , q, k) output by the signal generation unit 32.
  • the incoherent integration unit 33 executes incoherent integration on the acquired distance velocity signals f b, 1 (n Tx , n Rx , q, k). Specifically, for example, the incoherent integration unit 33 executes the incoherent integration according to the following equation (21).
  • incoherent integration signals f b, 1, inch (q, k) are generated.
  • the incoherent integration unit 33 outputs the generated incoherent integration signals f b, 1, inch (q, k) to the target candidate detection unit 34.
  • FIG. 8 shows the distance velocity signal f b, 1 (n Tx , n Rx , q, k) and the distance velocity signal f b, 1 (n Tx , n Rx , q) for each transmission channel and each reception channel.
  • K an example of the speed bin number corresponding to the distance velocity signal f b, 1 (n Tx , n Rx, q, k) are shown.
  • a noise component is superimposed on the distance velocity signals f b, 1 (n Tx , n Rx , q, k).
  • FIG. 9 shows the incoherent integrated signal f b, 1, inch (q, k), the distance bin number corresponding to the incoherent integrated signal f b, 1, inch (q, k), and the incoherent.
  • An example of the speed bin number corresponding to the integrated signal f b, 1, inch (q, k) is shown.
  • the electric power in the plurality of distance velocity signals f b, 1 (n Tx , n Rx , q, k) is integrated. That is, the signal strengths of N Tx ⁇ N Rx distance velocity signals f b, 1 (n Tx , n Rx , q, k) are integrated. As a result, the noise components are averaged (see FIGS. 8 and 9). As a result, the target detection capability of the radar device 1 can be improved.
  • ⁇ Target candidate detection unit 34 (step ST4)>
  • the target candidate detection unit 34 acquires the incoherent integration signals f b, 1, inch (q, k) output by the incoherent integration unit 33.
  • the target candidate detection unit 34 calculates the distance value corresponding to each target candidate based on the signal strength in the acquired incoherent integrated signal f b, 1, inch (q, k), and also calculates the distance value corresponding to each target candidate, and the individual target candidate. Calculate the speed value corresponding to.
  • individual target candidates are detected.
  • CA-CFAR Cell Average Constant False Allarm Rate
  • the number n tgt indicating each target candidate may be referred to as a “target candidate number”.
  • the target candidate detection unit 34 identifies the distance velocity signals f b, 1 (n Tx , n Rx , q ntgt , k ntgt) corresponding to each target candidate. Further, the target candidate detection unit 34 identifies the speed bin number qntgt corresponding to each target candidate. Further, the target candidate detection unit 34 identifies the distance bin number kntgt corresponding to each target candidate.
  • the target candidate detection unit 34 has the specified distance velocity signal f b, 1 (n Tx , n Rx , q ntgt , k ntgt ), the specified velocity bin number q ntgt, and the specified distance bin number k.
  • the ntgt is output to the coherent integrating unit 39.
  • the azimuth angles of the targets with respect to the individual receiving antennas can be regarded as the same.
  • the arrival distance difference ⁇ r nRx corresponding to each receiving antenna is expressed by the following equation (22).
  • the target azimuth angles ⁇ nRx and ⁇ 0 for each receiving antenna are expressed by the following equation (23).
  • ⁇ 0 is the target azimuth angle with respect to the reference point.
  • R Rx, 0 (n Rx ) is the distance between each receiving antenna and the target.
  • R0 is the distance between the reference point and the target.
  • ⁇ r Far, nRx, and ⁇ 0 are the arrival distance differences corresponding to the individual receiving antennas when the target azimuth with respect to the reference point is ⁇ 0 and the target is located in the distant field.
  • d nRx is the receiving antenna interval.
  • d nTx is the transmission antenna interval.
  • the target azimuths ⁇ nRx and ⁇ 0 with respect to the individual receiving antennas are approximated by the target azimuths ⁇ 0 with respect to the reference point. That is, the target azimuth angles ⁇ nRx and ⁇ 0 for each receiving antenna are approximated by the same value.
  • the signals f b, 1 (n Tx , n Rx , q ntgt , k ntgt ) corresponding to each transmission channel and corresponding to each reception channel are f b. , 1 (n Tx , n Rx ).
  • s 0 is a signal including a phase represented by the distance difference between the reference point and the target.
  • N fft is the Fourier transform score.
  • n fft is the bin number after the Fourier transform.
  • the phase difference between the receiving antennas is an integer multiple of d Rx sin ⁇ 0. Therefore, a fast Fourier transform can be performed. As a result, coherent integration can be performed with a small amount of calculation for signals corresponding to a plurality of receiving antennas (that is, signals corresponding to all receiving antennas).
  • the angular resolution can be improved by increasing the antenna opening. Therefore, it is conceivable to increase the antenna opening by increasing the number of receiving antennas.
  • one target may be located in the near field with respect to the plurality of receiving antennas, as shown in FIG. In this case, the target azimuths for each antenna will be different from each other.
  • the arrival distance difference ⁇ r nRx corresponding to each receiving antenna is expressed by the following equation (27). Further, the target azimuth angles ⁇ nRx and ⁇ 0 for each receiving antenna are expressed by the following equation (28).
  • the azimuth angle theta nRx goals for the individual receiving antennas, .theta.0 becomes azimuth theta 0 values different target relative to the reference point. That is, the target azimuth angles ⁇ nRx and ⁇ 0 for each receiving antenna have different values.
  • the target azimuth angles ⁇ nRx and ⁇ 0 with respect to the individual receiving antennas are different from each other. Therefore, it is difficult to perform a fast Fourier transform on a signal corresponding to a plurality of receiving antennas (that is, a signal corresponding to all receiving antennas). Therefore, the conventional radar device performs coherent integration on the signal by using the discrete Fourier transform. As a result, there is a problem that the amount of calculation increases as compared with the case of using the fast Fourier transform.
  • a plurality of integration groups are set so that each target candidate is approximated to be located in a distant field with respect to each integration group. Then, a coherent integral (that is, a first coherent integral) is performed on the signal corresponding to each integral group (that is, the signal in the integral group). This ensures that the first coherent integral is based on the far field, even if the individual targets are located in the near field with respect to the receiving antenna group. Therefore, a fast Fourier transform or a chirp Z transform (Chirp Z-Transform, CZT) can be used for the first coherent integral. This is intended to reduce the amount of calculation.
  • FIG. 12 shows an example of a plurality of integration groups.
  • FIG. 13 shows an example of one integral group among a plurality of integral groups.
  • NG indicates the number of integration groups (hereinafter referred to as “the number of integration groups”).
  • the number n G indicating each integral group may be referred to as an “integral group number”.
  • NRx and Far indicate the number of receiving antennas included in each integration group (hereinafter referred to as “the number of receiving antennas”).
  • the numbers n Rx and Far indicating individual receiving antennas in each integration group may be referred to as “receiving antenna numbers”.
  • the azimuth angle ⁇ ' is the azimuth angle ⁇ ". It is set within a range that can be approximated to be the same value as.
  • the target is located in the near field with respect to NRx, Far ⁇ NG receiving antennas (that is, all receiving antennas). In other words, the target is located in the vicinity of the NG integral group. However, as shown in FIG. 13, the target is approximated to be located in the distant field for each integral group.
  • ⁇ Integral unit calculation unit 35 (step ST5)>
  • the number of integration groups NG and the number of receiving antennas N Rx, Far are preset.
  • the integration unit calculation unit 35 calculates the number of integration groups NG and the number of receiving antennas N Rx, Far as follows.
  • the integration unit calculation unit 35 calculates the opening D Far in each integration group based on the azimuth angle difference ⁇ Far in each integration group according to the desired angular resolution and the desired integration performance. More specifically, the integration unit calculation unit 35 calculates the opening D Far that satisfies the condition shown in the following equation (29).
  • K Far is a preset coefficient.
  • D Near is an opening in the entire receiving antenna 21, that is, an opening in the receiving antenna group 24.
  • the integration unit calculation unit 35 calculates the number of receiving antennas N Rx, Far by the following equation (30). Further, the integration unit calculation unit 35 calculates the number of integration groups NG by the following equation (31).
  • floor (x) indicates the largest integer among the integers smaller than the variable x.
  • a plurality of integration unit calculation units 35 are used based on the set number of integration groups NG and the number of receiving antennas N Rx, Far , or based on the above-calculated number of integration groups NG and the number of receiving antennas N Rx, Far.
  • the receiving antennas 21 of the above are grouped. As a result, a plurality of integration groups are set.
  • the signals f b, 1 (n Tx , n Rx ) are represented by the signals f'b, 1 (n Tx , n G , n Rx, Far ).
  • the signals f b, 1 (n Tx , n Rx ) are signals corresponding to individual transmission channels and corresponding to individual reception channels for each target candidate.
  • the signals f'b , 1 (n Tx , n G , n Rx, Far ) are signals corresponding to individual transmission channels and individual integration groups for individual target candidates. ..
  • the signals f'b , 1 (n Tx , n G , n Rx, Far ) are represented by a distant field within the integration group.
  • the signals f'b , 1 (n Tx , n G , n Rx, Far ) are represented by the neighborhood field between the integration groups.
  • the signals f'b , 1 (n Tx , n G , n Rx, Far ) in the integration group are signals corresponding to the individual integration groups, that is, signals in the integration group.
  • the first integration unit 36 performs a chirp Z-transform for the signals f'b, 1 (n Tx , n G , n Rx, Far) in the integration group for each target candidate. Specifically, for example, the first integration unit 36 executes the chirp Z transform according to the following equation (33). As a result, the first integral signal f CZT (n Tx , n G , n czt ) corresponding to each integral group is generated.
  • AnG is a conversion start phase corresponding to each integration group.
  • W nG is the conversion phase interval corresponding to each integration group.
  • d czt, nG is the conversion distance interval corresponding to each integration group.
  • ⁇ s and nG are conversion start azimuths corresponding to individual integration groups.
  • ⁇ e and nG are conversion end azimuths corresponding to individual integration groups.
  • N czt is the CZT score corresponding to each integration group.
  • n czt is the azimuth bin number of the CZT corresponding to each integration group.
  • FIG. 14 shows an example of the receiving antenna position corresponding to each integration group, the conversion start azimuth ⁇ s, nG corresponding to each integration group, and the conversion end azimuth ⁇ e, nG corresponding to each integration group. ing.
  • the maximum power is shown at angles ⁇ nG and ⁇ 0.
  • the first integrated signal f CZT (n Tx , n G , n czt ) has the same azimuth bin number n'regardless of the receiving antenna position in the corresponding integration group.
  • the maximum power is shown in czt.
  • the first integral signals corresponding to the individual integral groups have different azimuth bin numbers. It indicates the maximum power. As a result, processing for associating these azimuth bin numbers is required.
  • the first integral signal f CZT (n Tx , n G , n czt ) corresponding to each integral group shows the maximum power at the same azimuth bin number n'cst. This makes it possible to eliminate the need for the process of associating the azimuth bin numbers. Therefore, the amount of calculation in the first integration unit 36 can be reduced. In addition, the integration loss in the first integration unit 36 can be reduced.
  • the chirp Z transform shown in the equation (33) can be realized by using the fast Fourier transform. As a result, the amount of calculation in the first integration unit 36 can be reduced. Further, the processing time by the first integration unit 36 can be shortened.
  • the first coherent integral can be executed in parallel for a plurality of integral groups.
  • the processing time by the first integration unit 36 can be shortened.
  • the first integration unit 36 outputs the first integration signal f CZT (n Tx , n G , n czt ) generated in this way to the second integration unit 37.
  • the first integration unit 36 may execute the fast Fourier transform shown in the following equation (38) instead of executing the chirp Z transform shown in the equation (33). As a result, the first integral signal f'ft (n Tx , n G , n fft ) corresponding to each integral group is generated.
  • the maximum power is shown at angles ⁇ nG and ⁇ 0.
  • the amount of calculation in the first integrating unit 36 can be reduced as compared with the case of using the discrete Fourier transform (that is, compared with the conventional radar device). ..
  • the integration loss in the first integration unit 36 can be reduced.
  • processing for associating the angle bin number indicating the maximum power is required (see FIG. 15).
  • ⁇ Second integration unit 37 (step ST7)>
  • the second integration unit 37 acquires the first integration signal f CZT (n Tx , n G , n czt ) output by the first integration unit 36.
  • the second integration unit 37 executes coherent integration with respect to the acquired first integration signal f CZT (n Tx , n G , n czt). That is, the second integration unit 37 executes the second coherent integration.
  • the second integral signal f DFT (n czt ) is generated.
  • the second coherent integral is based on the near field.
  • the second integration unit 37 executes the coherent integration according to the following equation (40).
  • R'0 is a relative distance to each target candidate.
  • P ncst is the target position in the azimuth bin number ncst of CZT.
  • P nczt is expressed by the following equation (41).
  • P nG is expressed by the following equation (42).
  • the azimuth angle ⁇ 0 satisfying the condition shown in the following equation (43) indicates the maximum power.
  • the azimuth angle ⁇ 0 indicating the maximum power is referred to as “ ⁇ 0, peak ”.
  • the azimuth bin number n ctz indicating the maximum power is described as "n ctz, peak ".
  • the second integration unit 37 outputs the second integration signal f DFT (n czt ) generated in this way to the angle calculation unit 38.
  • FIG. 17 shows an example of a plurality of first integral signals f CZT (n Tx , n G , n czt) corresponding to a plurality of integral groups. That is, FIG. 17 shows an example of N G number of first integration signal f CZT corresponding to N G number of integral group (n Tx, n G, n czt). Further, FIG. 17 shows an example of the N G number of first integration signal f CZT (n Tx, n G , n czt) second integration signal corresponding to f DFT (n czt).
  • a second integrated signal f DFT (n czt ) is generated by coherent integration with a plurality of first integrated signals f CZT (n Tx , n G , n czt).
  • the antenna opening can be increased by using a plurality of receiving antennas 21, but also a virtual array can be formed by using a plurality of transmitting antennas 14. This makes it possible to further increase the antenna opening. As a result, the angular resolution can be further improved.
  • the modulation processing in the transmission RF signal corresponding to each transmission channel is not limited to the code modulation (that is, code division) by the code modulation unit 12.
  • Such modulation processing may be performed as long as the separation unit 31 can realize the separation of the signals corresponding to the individual transmission channels.
  • such modulation processing may use time division, code division, frequency division, time division and code division, or frequency division and code division.
  • ⁇ Angle calculation unit 38 (step ST8)> The angle calculation unit 38 acquires the second integration signal f DFT (n czt ) output by the second integration unit 37. The angle calculation unit 38 calculates an angle value corresponding to each target candidate by using the acquired second integral signal f DFT (n czt).
  • the angle calculation unit 38 calculates the azimuth angles ⁇ 0, peak corresponding to the corresponding azimuth bin numbers n ctz, peak for each target candidate.
  • the azimuth angle ⁇ 0, peak is calculated by the following equation (44).
  • the radar device 1 includes a plurality of antennas (14, 21) including one or more transmitting antennas 14 and a plurality of receiving antennas 21, a radar signal processing device 7, and a radar signal processing device 7.
  • the radar signal processing device 7 includes an integration unit calculation unit 35 that sets a plurality of integration groups by grouping a plurality of receiving antennas 21, and each of the plurality of integration groups.
  • the first integral unit 36 that generates a plurality of first integral signals corresponding to a plurality of integral groups by executing the first coherent integral for the signals in the integral group corresponding to the above, and the plurality of first integrals.
  • a second integration unit 37 that generates a second integration signal by executing a second coherent integration on the signal, and an angle calculation unit 38 that calculates an angle value corresponding to each target candidate using the second integration signal.
  • the angular resolution can be improved by increasing the antenna aperture by using a plurality of antennas (14, 21). Further, by setting a plurality of integration groups, coherent integration for angle measurement can be facilitated. As a result, the amount of calculation can be reduced.
  • the radar signal processing method includes a plurality of antennas (14, 21) including one or more transmitting antennas 14 and a plurality of receiving antennas 21, and a radar signal processing device 7.
  • step ST5 in which the radar signal processing device 7 sets a plurality of integration groups by grouping a plurality of receiving antennas 21, and the radar signal processing device 7 Step ST6 to generate a plurality of first integrated signals corresponding to each of the plurality of integration groups by performing the first coherent integration for the signals in the integration group corresponding to each of the plurality of integration groups, and the radar signal.
  • Step ST7 in which the processing device 7 generates the second integrated signal by performing the second coherent integration on the plurality of first integrated signals, and the radar signal processing device 7 individually use the second integrated signal.
  • a step ST8 for calculating an angle value corresponding to a target candidate is provided.
  • the angular resolution can be improved by increasing the antenna aperture by using a plurality of antennas (14, 21). Further, by setting a plurality of integration groups, coherent integration for angle measurement can be facilitated. As a result, the amount of calculation can be reduced.
  • FIG. 18 is a block diagram showing a main part of the radar device according to the second embodiment.
  • FIG. 19 is a block diagram showing a main part of the second antenna module in the radar device according to the second embodiment.
  • FIG. 20 is a block diagram showing a main part of the first signal processor and the second signal processor in the radar device according to the second embodiment. The radar device according to the second embodiment will be described with reference to FIGS. 18 to 20.
  • FIG. 18 the same blocks as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Further, in FIG. 19, the same blocks as those shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. Further, in FIG. 20, the same blocks as those shown in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.
  • the radar device 1a includes a first antenna module 2_1, a first signal processor 3_1, and a display 4.
  • the radar device 1a includes a plurality of second antenna modules 2_2.
  • the radar device 1a includes a plurality of second antenna modules 2_2 and a plurality of second signal processors 3_2 corresponding to one-to-one.
  • Each second signal processor 3_2 includes a second receiver 6_2.
  • the first signal processor 3_1 and the plurality of second signal processors 3_2 constitute the main part of the radar signal processor 7a.
  • FIG. 18 only one second antenna module 2_2 out of the plurality of second antenna modules 2_2 is shown. Further, in FIG. 18, only one second signal processor 3_2 out of the plurality of second signal processors 3_2 is shown.
  • the second receiving unit 6_2 in each second antenna module 2_2 includes a local oscillation signal generation unit 11, a plurality of receiving antennas 21, a plurality of receivers 22, and a plurality of A / D converters. 23 is included.
  • the receiving antenna group 24 is composed of a plurality of receiving antennas 21.
  • the local oscillation signal generation unit 11 in the second reception unit 6_2 is the same as the local oscillation signal generation unit 11 in the transmission unit 5.
  • the plurality of receiving antennas 21, the plurality of receivers 22 and the plurality of A / D converters 23 in the second receiving unit 6_1 are the plurality of receiving antennas 21 and the plurality of receivers 22 in the first receiving unit 6_1. And a plurality of A / D converters 23. Therefore, detailed description thereof will be omitted.
  • the number of antenna modules N MDL in the radar device 1a may be referred to as “the number of modules”. Further, the number n MDL indicating each antenna module in the radar device 1a may be referred to as a “module number”.
  • the radar device 1a includes a plurality of antenna modules (including one first antenna module 2_1 and NMDL- 1 second antenna module 2_2).
  • the plurality of antenna modules may be arranged at equal intervals or may be arranged at irregular intervals.
  • an example in which a plurality of antenna modules are arranged at unequal intervals will be mainly described.
  • the individual antenna modules is intended to include a plurality of antennas (N including Tx transmit antennas 14 and N Rx receive antennas 21. Or comprises N Rx receive antennas 21.).
  • the plurality of antennas in the individual antenna modules may be arranged at equal intervals or may be arranged at irregular intervals.
  • an example in which a plurality of antennas in each antenna module are arranged at uneven intervals will be mainly described.
  • each second signal processor 3_2 includes a separation unit 31 and a signal generation unit 32.
  • the separation unit 31 and the signal generation unit 32 in the individual second signal processor 3_1 are the same as the separation unit 31 and the signal generation unit 32 in the first signal processor 3_1. Therefore, detailed description thereof will be omitted. Note that FIG. 20 illustrates only one second signal processor 3_2 out of the plurality of second signal processors 3_2.
  • the first signal processor 3_1 in the radar device 1a includes a separation unit 31, a signal generation unit 32, an incoherent integration unit 33, a target candidate detection unit 34, an integration unit calculation unit 35, and a first integration unit 36.
  • the second integration unit 37 and the angle calculation unit 38 are included.
  • the first signal processor 3_1 in the radar device 1a includes an arrangement equal spacing section 51.
  • the integration unit calculation unit 35, the first integration unit 36, the second integration unit 37, and the arrangement equal spacing unit 51 constitute the main part of the coherent integration unit 39a.
  • the radar device 1a includes a receiving antenna group 24 of NMDLs. That is, the radar device 1a includes N Rx ⁇ N MDL receiving antennas 21.
  • the integration unit calculation unit 35 sets N MDL integration groups by grouping N Rx ⁇ N MDL receiving antennas 21 for each antenna module.
  • each antenna module the plurality of antennas in each antenna module are arranged at unequal intervals. Therefore, in each antenna module, there are a plurality of antenna arrangement intervals d Rx, nRx, and Far that are different from each other. In other words, in each integration group, there are a plurality of antenna arrangement intervals d Rx, nRx, Far that are different from each other (see FIG. 22).
  • the arrangement equal spacing unit 51 calculates the greatest common divisor ⁇ d Rx, Far in a plurality of antenna arrangement intervals d Rx, nRx, Far for each integration group. Specifically, for example, the arrangement equal spacing unit 51 calculates the greatest common divisor ⁇ d Rx, Far by the following equation (45).
  • GCD (x) indicates the greatest common divisor in the array x.
  • the arrangement equal spacing unit 51 is based on the calculated greatest common divisor ⁇ d Rx, Far , and the following signals in the integration group f'b , 1 (n Tx, n G , n Rx, Far, GCD). ) Is generated. That is, the signal f'b , 1 (n Tx , n G , n Rx, Far, GCD ) in the integration group is a signal corresponding to each transmission channel and is a signal corresponding to each integration group. ..
  • a plurality of signals f'b , 1 (n Tx , n G , n Rx, Far, GCD ) in the integration group are included in the corresponding integration group based on the greatest common divisor ⁇ d Rx, Far calculated above.
  • This is a signal in a state where the antennas of the above are virtually arranged at equal intervals.
  • FIG. 22 shows an example of such a state.
  • the arrangement equal spacing unit 51 generates signals f'b, 1 (n Tx , n G , n Rx, Far, GCD ) in the integration group by the following equation (46).
  • n Rx, Far, and GCD are receiving antenna numbers in a state where a plurality of antennas in the corresponding integration group are virtually arranged at equal intervals.
  • the arrangement equal spacing unit 51 outputs the signals f'b , 1 (n Tx , n G , n Rx, Far, GCD ) in the integration group thus generated to the first integration unit 36. ..
  • the first integration unit 36 acquires signals f'b, 1 (n Tx , n G , n Rx, Far, GCD ) in the integration group output by the arrangement equalization unit 51.
  • the first integration unit 36 replaces the signals f'b, 1 (n Tx , n G , n Rx, Far) in the integration group described in the first embodiment.
  • the acquired signals in the integration group f'b , 1 (n Tx, n G , n Rx, Far, GCD ) are used.
  • a fast Fourier transform or a chirp Z transform is used for the first coherent integral.
  • the first integration signal f CZT (n Tx , n G , n czt ) is generated.
  • the first integration unit 36 outputs the generated first integration signal f CZT (n Tx , n G , n czt ) to the second integration unit 37.
  • the operation of the second integrating unit 37 is the same as that described in the first embodiment. Further, the operation of the angle calculation unit 38 is the same as that described in the first embodiment. Therefore, detailed description thereof will be omitted.
  • the grating level becomes large (see FIG. 23). As a result, the grating level may exceed the desired level. This also applies when the antenna arrangement interval exceeds the wavelength of the radio wave (see FIG. 23).
  • the grating can be reduced by arranging a plurality of antenna modules at unequal intervals (see FIG. 24). Therefore, the total number of antenna modules in the radar device 1a (hereinafter referred to as “total number of modules”) can be reduced in order to suppress the grating level to a desired level or lower. Further, by arranging a plurality of antennas in each antenna module at unequal intervals, the grating can be reduced (see FIG. 24). Therefore, in order to suppress the grating level to a desired level or less, the total number of antennas in each antenna module (hereinafter referred to as “total number of antennas”) can be reduced.
  • arrangement equal spacing processing the processes executed by the arrangement equal spacing unit 51 may be collectively referred to as "arrangement equal spacing processing".
  • functions of the arrangement equal spacing unit 51 may be collectively referred to as “arrangement equal spacing function”.
  • the reference numeral of "F11" may be used for the arrangement equal spacing function.
  • the hardware configuration of the main part of the first signal processor 3_1 is the same as that described with reference to FIGS. 4 to 6 in the first embodiment. Therefore, detailed description thereof will be omitted.
  • the first signal processor 3_1 has a plurality of functions (separation function, signal generation function, incoherent integration function, target candidate detection function, integration unit calculation function, arrangement equal spacing function, first integration function, second. It includes an integration function and an angle calculation function.) It has F1 to F8 and F11.
  • Each of the plurality of functions F1 to F8 and F11 may be realized by the processor 41 and the memory 42, or may be realized by the processing circuit 43.
  • the processor 41 may include a dedicated processor corresponding to each of the plurality of functions F1 to F8 and F11.
  • the memory 42 may include a dedicated memory corresponding to each of the plurality of functions F1 to F8 and F11.
  • the processing circuit 43 may include a dedicated processing circuit corresponding to each of the plurality of functions F1 to F8 and F11.
  • the hardware configuration of the main part of the second signal processor 3_1 is the same as the hardware configuration of the main part of the first signal processor 3_1. Therefore, detailed description thereof will be omitted.
  • the second signal processor 3_2 has a plurality of functions (including a separation function and a signal generation function) F1 and F2.
  • Each of the plurality of functions F1 and F2 may be realized by the processor 41 and the memory 42, or may be realized by the processing circuit 43 (FIG. 25, FIG. 26 or FIG. 27). reference).
  • the processor 41 may include a dedicated processor corresponding to each of the plurality of functions F1 and F2.
  • the memory 42 may include a dedicated memory corresponding to each of the plurality of functions F1 and F2.
  • the processing circuit 43 may include a dedicated processing circuit corresponding to each of the plurality of functions F1 and F2.
  • the separation unit 31 executes the separation process (step ST11).
  • the signal generation unit 32 executes the signal generation process (step ST12).
  • step ST5 the integration unit calculation unit 35 sets a plurality of integration groups corresponding to a plurality of antenna modules on a one-to-one basis.
  • the placement equal spacing unit 51 executes the placement equal spacing process (step ST21).
  • step ST6 the first integration unit 36 replaces the signal f'b , 1 (n Tx, n G , n Rx, Far ) in the integration group with the signal f'b , 1 (n Tx) in the integration group. , N G , n Rx, Far, GCD ).
  • the plurality of antenna modules (2_1, _1) are arranged at unequal intervals. As a result, the total number of modules can be reduced in achieving the desired grating level. As a result, the radar device 1a can be realized at low cost.
  • a plurality of antennas (14, 21) are arranged at unequal intervals. As a result, the total number of antennas can be reduced in achieving the desired grating level. As a result, the radar device 1a can be realized at low cost.
  • the plurality of antennas (14, 21) are evenly spaced based on the greatest common divisor in the plurality of arrangement intervals (antenna arrangement intervals) corresponding to the plurality of antennas (14, 21).
  • the first coherent integral is performed assuming that it is arranged in, and the first coherent integral uses a fast Fourier transform. This makes it possible to facilitate the first coherent integration even when a plurality of antennas (14, 21) are arranged at unequal intervals. That is, the amount of calculation can be reduced and the processing time can be shortened.
  • the plurality of antennas (14, 21) are evenly spaced based on the greatest common divisor in the plurality of arrangement intervals (antenna arrangement intervals) corresponding to the plurality of antennas (14, 21).
  • the first coherent integral is performed assuming that it is arranged in, and the first coherent integral uses the charp Z-transform. This makes it possible to facilitate the first coherent integration even when a plurality of antennas (14, 21) are arranged at unequal intervals. That is, the amount of calculation can be reduced and the processing time can be shortened.
  • the radar signal processing method according to the present disclosure can be used for a radar device.
  • the radar device according to the present disclosure can be used, for example, in a vehicle.
  • 1,1a Radar device 2_1 1st antenna module, 2_1 2nd antenna module, 3_1 1st signal processor, 3_1 2nd signal processor, 4 display, 5 transmitter, 6_1 first receiver, 6_1 second receiver Unit, 7, 7a radar signal processing device, 11 local oscillation signal generator, 12 code modulator, 13 transmitter, 14 transmit antenna, 15 transmit antenna group, 21 receive antenna, 22 receiver, 23 A / D converter, 24 receiving antenna group, 31 separation unit, 32 signal generation unit, 33 incoherent integration unit, 34 target candidate detection unit, 35 integration unit calculation unit, 36 first integration unit, 37 second integration unit, 38 angle calculation unit, 39 , 39a Coherent integration unit, 41 processor, 42 memory, 43 processing circuit, 51 arrangement equal spacing unit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

L'invention concerne un dispositif radar (1) comprenant : une pluralité d'antennes (14, 21) comprenant une ou plusieurs antennes d'émission (14) et une pluralité d'antennes de réception (21) ; et un dispositif de traitement de signaux radar (7). Le dispositif de traitement de signaux radar (7) comprend : une unité de calcul d'unités d'intégration (35) qui définit une pluralité de groupes d'intégration par regroupement de la pluralité d'antennes de réception (21) ; une première unité d'intégration (36) qui exécute une première intégration cohérente sur un signal interne de groupe d'intégration correspondant à chaque groupe de la pluralité de groupes d'intégration, de manière à générer une pluralité de premiers signaux d'intégration correspondant respectivement à la pluralité de premiers groupes d'intégration ; une seconde unité d'intégration (37) qui exécute une seconde intégration cohérente sur la pluralité de premiers signaux d'intégration de façon à générer un second signal d'intégration ; et une unité de calcul d'angle (38) qui calcule une valeur d'angle correspondant à chaque candidat cible individuel à l'aide du second signal d'intégration.
PCT/JP2020/021447 2020-05-29 2020-05-29 Dispositif radar et procédé de traitement de signaux radar WO2021240810A1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003240832A (ja) * 2002-02-21 2003-08-27 Toshiba Corp 電波到来角度推定装置、及び推定方法
JP2005257384A (ja) * 2004-03-10 2005-09-22 Mitsubishi Electric Corp レーダ装置およびアンテナ装置
WO2011092813A1 (fr) * 2010-01-28 2011-08-04 トヨタ自動車株式会社 Dispositif de détection d'obstacles
WO2014199609A1 (fr) * 2013-06-13 2014-12-18 パナソニック株式会社 Dispositif de radar
WO2017149596A1 (fr) * 2016-02-29 2017-09-08 三菱電機株式会社 Dispositif de radar
WO2018046353A1 (fr) * 2016-09-08 2018-03-15 Audi Ag Véhicule à moteur muni d'un dispositif de détection pour la détection à résolution angulaire de l'environnement du véhicule à moteur

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Publication number Priority date Publication date Assignee Title
JP2003240832A (ja) * 2002-02-21 2003-08-27 Toshiba Corp 電波到来角度推定装置、及び推定方法
JP2005257384A (ja) * 2004-03-10 2005-09-22 Mitsubishi Electric Corp レーダ装置およびアンテナ装置
WO2011092813A1 (fr) * 2010-01-28 2011-08-04 トヨタ自動車株式会社 Dispositif de détection d'obstacles
WO2014199609A1 (fr) * 2013-06-13 2014-12-18 パナソニック株式会社 Dispositif de radar
WO2017149596A1 (fr) * 2016-02-29 2017-09-08 三菱電機株式会社 Dispositif de radar
WO2018046353A1 (fr) * 2016-09-08 2018-03-15 Audi Ag Véhicule à moteur muni d'un dispositif de détection pour la détection à résolution angulaire de l'environnement du véhicule à moteur

Non-Patent Citations (1)

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Title
KAGEME, SATOSHI ET AL.: "Coherent Integration method of Frequency Division MIMO Radar Using the Chirp Z-Transform for a Moving Target", IEICE TECHNICAL REPORT, vol. 117, no. 403, 18 January 2018 (2018-01-18), pages 47 - 52, XP009519045, ISSN: 0913-5685 *

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