WO2013080570A1 - レーダ装置 - Google Patents
レーダ装置 Download PDFInfo
- Publication number
- WO2013080570A1 WO2013080570A1 PCT/JP2012/007717 JP2012007717W WO2013080570A1 WO 2013080570 A1 WO2013080570 A1 WO 2013080570A1 JP 2012007717 W JP2012007717 W JP 2012007717W WO 2013080570 A1 WO2013080570 A1 WO 2013080570A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- radar
- unit
- target
- transmission
- antenna
- Prior art date
Links
Images
Classifications
-
- 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
-
- 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
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/91—Radar or analogous systems specially adapted for specific applications for traffic control
-
- 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
-
- 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
- G01S13/08—Systems for measuring distance only
- G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
- G01S13/22—Systems for measuring distance only using transmission of interrupted, pulse modulated waves using irregular pulse repetition frequency
-
- 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
- G01S13/08—Systems for measuring distance only
- G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
- G01S13/26—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
- G01S13/28—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave with time compression of received pulses
- G01S13/284—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave with time compression of received pulses using coded pulses
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/056—Detecting movement of traffic to be counted or controlled with provision for distinguishing direction of travel
-
- 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
- G01S7/28—Details of pulse systems
- G01S7/285—Receivers
- G01S7/288—Coherent receivers
- G01S7/2886—Coherent receivers using I/Q processing
Definitions
- the present disclosure relates to a radar apparatus that receives, at a receiving antenna, a reflected wave signal reflected by a target, and estimates a distance or an arrival direction to the target.
- the radar apparatus transmits a high frequency radar transmission signal from the measurement point to space, receives a reflected wave signal reflected by the target, and measures at least one of the distance and direction between the measurement point and the target.
- development of a radar device has been advanced to estimate the distance or arrival direction to a target including cars and pedestrians by measuring with high resolution using a radar transmission signal of short wavelength including microwave or millimeter wave. There is.
- the radar apparatus receives a mixed signal of each reflected wave from a close target and a far target. Range side lobes occur in the reflected wave signal from a close target, and when the range side lobe and the main lobe of the reflected wave signal from a distant target are mixed, detection of the distant target is possible Accuracy is degraded.
- low range sidelobe characteristics a transmission code with autocorrelation characteristics that results in low range sidelobe levels. Transmission of pulse waves or pulse modulated waves is required.
- the radar apparatus mixes the signal of each reflected wave from a car and a pedestrian with different radar reflection cross sections (RCS: Radar cross section) when the car and the pedestrian exist at the same distance from the measurement point.
- RCS radar reflection cross section
- a pedestrian's radar reflection cross section is lower than that of a car.
- the radar apparatus is required to properly receive each reflected wave signal from the automobile and the pedestrian even if the automobile and the pedestrian exist at the same distance from the measurement point.
- the signal level of the reflected wave signal changes depending on the distance or type of the target. For this reason, the radar apparatus is required to have a large reception dynamic range to the extent that it can receive reflected wave signals having various signal levels.
- an antenna is mechanically scanned or a narrow angle directional beam is electronically scanned to transmit a pulse wave or a pulse modulation wave, and receive a reflected wave signal reflected by a target Radar devices are known.
- the reflected wave signal reflected from the target is received by a plurality of antennas, and the reception phase difference in each received reflected wave signal is measured to obtain.
- a radar device that estimates the angle of arrival using resolution higher than directivity.
- the former radar device since a single antenna is used to transmit and receive radio waves, it takes time for the antenna to scan for detection of a target. For this reason, in order to detect a target moving at high speed, a large number of scans are required as high-resolution measurement is required, and it becomes difficult to track and detect the movement of the target.
- the latter radar device can estimate the arrival angle by thinning out the scanning interval and performing signal processing, as compared with a radar device using a single antenna, and can improve the detection accuracy of the target. Also, even if the target moves at high speed, the arrival angle can be estimated following the movement of the target.
- Patent Document 1 is known as a prior art in which a reflected wave signal having high correlation among reflected wave signals received by a plurality of antennas is separated and the direction of arrival is measured.
- the super resolution antenna of Patent Document 1 performs Fourier transform on a received signal received by a plurality of element antennas, and weights signal components for each filter bank according to the Doppler frequency generated by the Fourier transform.
- the super resolution antenna extracts a desired filter bank component from the weighted signal component, and estimates the signal arrival direction of the target based on the extracted signal component of the element antenna.
- the correlation of each target is high, and the Doppler frequency of each target is sufficiently different, the received signal from each target is separated, and the arrival direction of each target is estimated. it can.
- Patent Document 1 for example, when the radar apparatus is installed at a high position of a predetermined height from the ground, the calculation amount of the arrival direction estimation of the target is reduced, and the estimation accuracy of the arrival direction is improved. Is difficult.
- the present disclosure has been made in view of the above-described conventional circumstances, and an object of the present disclosure is to provide a radar device that reduces the amount of calculation of estimation of the arrival direction of a target and improves estimation accuracy of the arrival direction.
- the present disclosure is a radar device installed at a predetermined height from the ground, which converts a transmission code into a high frequency radar transmission signal, and a predetermined direction from the position of the predetermined height toward the ground Arrival of the target using a radar transmission unit that transmits the radar transmission signal from the transmission antenna that is tilted to the side and a plurality of antenna system processing units that receive a reflected wave signal that is the radar transmission signal reflected by the target A radar receiving unit for estimating a direction, and the radar receiving unit generates a correlation matrix including phase difference information resulting from the arrangement of receiving antennas based on the outputs from the plurality of antenna system processing units A correlation matrix generation unit, a distance estimation unit for estimating a distance to the target based on each output from the plurality of antenna system processing units, and a front based on outputs of the distance estimation unit Having determined the elevation component of the target, the output of the azimuthal component is variable with direction vector the correlation matrix generation unit, and a DOA estimating unit for estimating the direction of arrival
- FIG. 13 is a diagram showing an example of a measurement area in the case where the conventional radar device is disposed at a height of 5 m above the ground.
- the direction vector corresponding to the reception phase difference information between antennas determined by the arrival angle ⁇ of the target and the plurality of antenna spacings is affected by the inter-antenna deviation of the directivity pattern of the vertical plane of the receiving antenna (see FIG. 14). ). That is, the direction vector includes the inter-antenna deviation component depending on the elevation direction, in addition to the inter-antenna deviation component depending on the azimuth angle direction of the antenna element.
- FIG. 14 is a diagram showing an example of the characteristic of directivity in the elevation direction of the antenna.
- the perpendicular direction to the detection range of 40 m has a range of 38 degrees. 14 in the range of 5 m to 10 m, in the range of 10 m to 20 m in FIG. 13 in the range of 20 m to 40 m in FIG. Directivity (3) is used.
- the direction vector includes an inter-antenna deviation component depending on the elevation direction other than the azimuth direction of the antenna element.
- the direction estimation accuracy differs depending on the distance at which the target is present, which causes variation in the direction estimation accuracy of the radar device.
- the inter-antenna deviation component can be corrected by including in the direction vector the amplitude and phase deviation information generated depending on the azimuth angle direction ⁇ and the elevation angle direction ⁇ and generated between the receiving antenna elements.
- the arrival direction of the reflected wave signal can be estimated after the direction estimation accuracy dependence on the elevation direction ⁇ is reduced.
- the conventional radar device when installed at a high place, two variables of the azimuth angle direction ⁇ and the elevation angle direction ⁇ are used, so the amount of calculation of evaluation function values for estimating the arrival direction increases.
- the variable range of the azimuth direction ⁇ is divided into N and the variable range of the elevation direction ⁇ is divided into M
- the calculation amount of the evaluation function value is (N ⁇ M) times, and the calculation amount of the evaluation function value is Increase.
- FIG. 1 is an explanatory view of a straight line in the tilt angle ( ⁇ 0 ) direction of the radar antenna of the radar device 1 in the first embodiment and an elevation angle ⁇ (k Rx ) with respect to a target.
- the transmitting antenna Tx-ant and the plurality of receiving antennas Rx-ant1 to Rx-ant4 of the radar device 1 according to the present embodiment are collectively referred to as a radar antenna RA, and the plurality of receiving antennas Rx-ant1 to Rx- ant 4 forms an array antenna.
- a radar antenna RA of the radar device 1 is shown in FIG.
- FIG. 2 is a block diagram schematically showing the internal configuration of the radar device 1 of the first embodiment.
- FIG. 3 is a block diagram showing the internal configuration of the radar device 1 of the first embodiment in detail.
- FIG. 4 is a diagram showing the relationship between the transmission interval Tw of the radar transmission signal and the transmission period Tr.
- FIG. 5 is a block diagram showing an internal configuration of a transmission signal generation unit 2 r according to a modification of the transmission signal generation unit 2.
- the radar device 1 is installed at a predetermined height H ant from the ground GND.
- the called installation height H ant predetermined height H ant in the following description.
- the radar antenna RA of the radar device 1 is inclined in the direction of an inclination angle ( ⁇ 0 ) from the position of the installation height H ant toward the ground GND.
- the radar device 1 transmits a radar transmission signal generated by the radar transmission unit Tx from the transmission antenna Tx-ant, and receives a signal of a reflected wave in which the transmitted radar transmission signal is reflected by the target TAR at the array antenna.
- the radar device 1 performs signal processing on the signals received by the array antenna to estimate the distance between the radar device 1 and the target TAR and the arrival direction of the target.
- the target TAR is an object to be detected by the radar device 1 and includes, for example, a car or a person, and the same applies to the following embodiments.
- the radar device 1 shown in FIG. 2 is configured to include a reference signal oscillator Lo, a radar transmitter Tx, and a radar receiver Rx.
- the radar transmission unit Tx is configured to include the transmission signal generation unit 2 and the transmission RF unit 3 to which the transmission antenna Tx-ant is connected.
- the reference signal oscillator Lo is connected to the radar transmitter Tx and the radar receiver Rx, and supplies the signal from the reference signal oscillator Lo to the radar transmitter Tx and the radar receiver Rx in common, thereby enabling the radar transmitter Tx and the radar. Synchronize the processing of the reception unit Rx.
- the radar reception unit Rx is configured to include four antenna system processing units 10, 10a, 10b, and 10c, a correlation matrix generation unit 20, a distance estimation unit 21, a direction vector storage unit 22, and an arrival direction estimation unit 23.
- the radar receiver Rx shown in FIG. 2 has four antenna system processors, but the number of antenna system processors is not limited to four and may be two or more. Since each antenna system processing unit has the same configuration, hereinafter, the antenna system processing unit 10 will be described as an example.
- the antenna system processing unit 10 is configured to include the reception RF unit 11 to which the reception antenna Rx-ant 1 is connected, and the signal processing unit 12.
- the signal processing unit 12 is configured to include at least a correlation value calculation unit 18 and a coherent integration unit 19.
- the radar transmitter Tx shown in FIG. 3 is configured to include the transmission signal generator 2 and the transmission RF unit 3 to which the transmission antenna Tx-ant is connected.
- the transmission signal generation unit 2 illustrated in FIG. 3 includes a code generation unit 4, a modulation unit 5, an LPF (Low Pass Filter) 6, and a D / A conversion unit 7.
- the LPF 6 is configured to be included in the transmission signal generation unit 2
- the radar is external to the transmission signal generation unit 2 and the output from the D / A conversion unit 7 is input. It may be configured inside the transmission unit Tx.
- the transmission RF unit 3 shown in FIG. 3 is configured to include a frequency conversion unit 8 and an amplifier 9.
- the transmission signal generation unit 2 generates a transmission reference clock signal obtained by multiplying the reference signal by a predetermined factor based on the reference signal generated by the reference signal oscillator Lo. Each unit of the transmission signal generation unit 2 operates based on the generated transmission reference clock signal.
- the transmission signal generation unit 2 periodically generates a transmission signal r (k Tx , M) of the baseband shown in Expression (1) by modulating the code sequence C n of the code length L.
- n is 1 to L
- L represents the code length of the code sequence C n .
- k Tx represents discrete time in the radar transmission unit Tx
- k Tx is 1 to (Nr + Nu), which is discrete time representing modulation timing for generation of a transmission signal.
- the transmission signal r (k Tx , M) represents the transmission signal at discrete time k Tx of the Mth transmission period Tr, and is orthogonal obtained by multiplying the in-phase signal component I (k Tx , M) by the imaginary unit j. It becomes the addition result with signal component Q (k Tx , M) (refer Formula (1)).
- the code generation unit 4 generates a transmission code of a code sequence C n of a code length L for each transmission cycle Tr.
- the elements of the code sequence C n are configured using, for example, a binary value of [ ⁇ 1, 1] or a quaternary value of [1, ⁇ 1, j, ⁇ j].
- the transmission code is, for example, a code sequence forming a pair of complementary codes, a Barker code sequence, a Golay code sequence, an M-sequence code, and a code forming a spano code, because the radar device 1 has low range side lobe characteristics. It is preferable that it is a code including at least one of the sequences.
- the code generation unit 4 outputs the generated transmission code of the code sequence C n to the modulation unit 5.
- the transmission code of the code sequence C n are described as conveniently transmission code C n.
- the code generation unit 4 uses two transmission cycles (2Tr) to transmit the transmission codes P n and Q n alternately forming pairs in each transmission cycle. Generate each. That is, the code generation unit 4 generates one transmission code P n constituting the pair of complementary codes in the Mth transmission cycle, and outputs the generated transmission code P n to the modulation unit 5, and complements in the subsequent (M + 1) th transmission cycle. The other transmission code Q n constituting the code pair is generated and output to the modulation unit 5. Similarly, in the (M + 2) th and subsequent transmission cycles, the code generation unit 4 repeats the transmission codes P n and Q n using the Mth and (M + 1) th two transmission cycles as one unit. It is generated and output to the modulation unit 5.
- 2Tr two transmission cycles
- the modulator 5 receives the transmission code C n output from the code generator 4.
- the modulation unit 5 pulse-modulates the input transmission code C n to generate a baseband transmission signal r (k Tx , M) of Expression (2).
- the pulse modulation is amplitude modulation, amplitude shift keying (ASK), or phase shift keying (PSK), and the same applies to each of the following embodiments.
- phase modulation the code sequence C n is, for example, BPSK (Binary Phase Shift Keying) in binary phase modulation of [ ⁇ 1, 1], and the code sequence C n is, for example, [1, ⁇ 1, j, QPSK (Quadrature Phase Shift Keying) or 4-phase PSK is used in 4-value phase modulation of -j]. That is, in phase modulation (PSK), predetermined modulation symbols in the constellation on the IQ plane are assigned.
- Modulation unit 5 outputs generated transmission signal r (k Tx, M) transmission signal r (k Tx, M) below preset limits bandwidth of the, to the D / A converter 7 via the LPF6 Do.
- the LPF 6 may be omitted in the transmission signal generation unit 2, and the same applies to the following embodiments.
- the D / A conversion unit 7 converts the digital transmission signal r (k Tx , M) output from the modulation unit 5 into an analog transmission signal.
- the D / A converter 7 outputs an analog transmission signal to the transmission RF unit 3.
- the transmission RF unit 3 generates a transmission reference signal of a carrier frequency band obtained by multiplying the reference signal by a predetermined multiple based on the reference signal generated by the reference signal oscillator Lo. Each unit of the transmission RF unit 3 operates based on the generated transmission reference signal.
- the frequency converter 8 receives the analog transmission signal output from the D / A converter 7 and up-converts the baseband transmission signal using the input transmission signal and the transmission reference signal.
- the frequency converter 8 generates a high frequency radar transmission signal, and outputs the generated radar transmission signal to the amplifier 9.
- the amplifier 9 receives the radar transmission signal output from the frequency conversion unit 8, amplifies the signal level of the input radar transmission signal to a predetermined signal level, and outputs the signal level to the transmission antenna Tx-ant.
- the amplified radar transmission signal is transmitted via the transmission antenna Tx-ant.
- the transmission antenna Tx-ant transmits the radar transmission signal output from the transmission RF unit 3.
- the radar transmission signal shown in FIG. 4 is transmitted during the transmission period Tw in the transmission period Tr, and is not transmitted during the non-signal period (Tr-Tw).
- a signal obtained by multiplying the reference signal generated by the reference signal oscillator Lo by a predetermined multiple is commonly used in the transmission RF unit 3 and the reception RF units of the antenna system processing units 10, 10a, 10b, and 10c. It is supplied. Thereby, the processing between the transmission RF unit 3 and the plurality of reception RF units can be synchronized.
- the transmission signal generation unit 2 may be provided with a transmission code storage unit CM which stores the transmission code C n generated by the transmission signal generation unit 2 in advance without the code generation unit 4 (see FIG. 5). .
- the transmission code storage unit CM may store a pair of complementary codes, for example, transmission codes An and B n in response to a case where the transmission signal generation unit 4 generates a transmission code that is a pair of complementary codes.
- the transmission code storage unit CM is applicable not only to the first embodiment but also to each embodiment described later.
- the transmission signal generation unit 2r shown in FIG. 5 is configured to include a transmission code storage unit CM, a transmission code control unit CT3, a modulation unit 5r, an LPF 6r, and a D / A conversion unit 7.
- the transmission code control unit CT3 transmits a transmission code C n (or a pair of complementary codes for each transmission cycle Tr based on a reference clock signal obtained by multiplying the reference signal output from the reference signal oscillator Lo by a predetermined factor.
- the code A n and the transmission code B n are cyclically read from the transmission code storage unit CM and output to the modulation unit 5 r.
- the operations after being output to the modulation unit 5r are the same as those of the modulation unit 5 and the LPF 6 described above, and thus the description of the operation is omitted.
- the radar receiver Rx shown in FIG. 3 includes, for example, four antenna system processors 10, 10a, 10b and 10c, correlation matrix generator 20, and distance estimation provided corresponding to the number of receiving antennas constituting the array antenna.
- the configuration includes a unit 21, a direction vector storage unit 22, and an arrival direction estimation unit 23.
- the antenna system processing unit 10 is configured to include the reception RF unit 11 to which the reception antenna Rx-ant 1 is connected, and the signal processing unit 12.
- the reception RF unit 11 is configured to include an amplifier 13, a frequency conversion unit 14, and a quadrature detection unit 15.
- the signal processing unit 12 is configured to include two A / D conversion units 16 and 17, a correlation value calculation unit 18, and a coherent integration unit 19.
- the radar receiver 3 periodically calculates each transmission cycle Tr as a signal processing section in the signal processor of each antenna system processor.
- the reception antenna Rx-ant1 receives a reflected wave signal in which the radar transmission signal transmitted from the radar transmission unit Tx is reflected by the target TAR.
- the reception signal received by the reception antenna Rx-ant1 is input to the reception RF unit 11.
- the reception RF unit 11 Similar to the transmission RF unit 3, the reception RF unit 11 generates a reception reference signal of a carrier frequency band obtained by multiplying the reference signal by a predetermined factor based on the reference signal generated by the reference signal oscillator Lo. Each unit of the reception RF unit 11 operates based on the generated reception reference signal.
- the amplifier 13 receives the high frequency reception signal received by the reception antenna Rx-ant1, amplifies the signal level of the input reception signal, and outputs the amplified signal to the frequency conversion unit 14.
- the frequency converter 14 receives the received signal output from the amplifier 13 and down-converts the received high frequency signal using the received high frequency received signal and the received reference signal.
- the frequency converter 14 generates a baseband received signal, and outputs the generated received signal to the quadrature detector 15.
- the quadrature detection unit 15 performs quadrature detection on the reception signal output from the frequency conversion unit 14 to generate a reception signal configured using an in-phase signal and a quadrature signal. .
- the quadrature detection unit 15 outputs the in-phase signal of the generated reception signals to the A / D conversion unit 16, and outputs the quadrature signal to the A / D conversion unit 17.
- the A / D conversion unit 16 samples the in-phase signal of the baseband output from the quadrature detection unit 15 at each discrete time k Rx and converts the in-phase signal of analog data into digital data.
- the A / D converter 16 outputs the in-phase signal component of the converted digital data to the correlation value calculator 18.
- the A / D conversion unit 17 samples the baseband quadrature signal output from the quadrature detection unit 15 for each discrete time k Rx and converts the quadrature signal of analog data into digital data.
- the A / D converter 17 outputs the orthogonal signal component of the converted digital data to the correlation value calculator 18.
- the reception signal at the discrete time k Rx of the Mth transmission period Tr converted by the A / D conversion units 16 and 17 has the in-phase signal component Ir (k Rx , M) of the reception signal and the quadrature of the reception signal.
- the signal component Qr (k Rx , M) is used to represent the complex signal x (k Rx , M) of Equation (2).
- the digital received signal x (k Rx , M) output from the A / D conversion units 16 and 17 is referred to as a discrete sample value x (k Rx , M).
- the correlation value calculator 18 calculates the discrete sample values Ir (k Rx , M) and Qr (k Rx , M) output from the A / D converters 16 and 17, that is, discrete sample values x (k) as reception signals. Input Rx , M).
- the correlation value calculator 18 transmits the code length L transmitted in each transmission cycle Tr shown in the first stage of FIG. 6 at each discrete time k Rx based on the reception reference clock signal obtained by multiplying the reference signal by a predetermined factor.
- the transmission code C n of is periodically generated. n is 1 to L, and L represents the code length of the code sequence C n .
- the first stage of FIG. 6 represents the transmission timing of the radar transmission signal.
- the correlation value calculator 18 calculates a sliding correlation value AC (k Rx , M) between the input discrete sample value x (k Rx , M) and the transmission code C n .
- AC (k Rx , M) represents a sliding correlation value at discrete time k Rx .
- the sliding correlation value AC (k Rx , M) is calculated according to.
- the correlation value calculator 18 outputs the sliding correlation value AC (k Rx , M) for each discrete time k Rx calculated according to Equation (3) to the coherent integrator 19.
- the second and third stages of FIG. 6 represent the reception timing for the radar transmission signal.
- the second stage of FIG. 6 shows the range of the measurement period when the reception signal is received at the array antenna after the delay time ⁇ 1 has elapsed from the start of transmission of the radar transmission signal.
- the third stage of FIG. 6 the range of the measurement period is shown in the case where the received signal is received at array antenna after a delay time tau 2 from the time start of transmission of the radar transmission signal.
- the delay times .tau.1 and .tau.2 are given by equations (4) and (5), respectively.
- the correlation value calculator 18 may limit the measurement range, that is, the range of the discrete time k Rx according to the existing range of the target TAR to be measured by the radar device 1. Thus, the radar device 1 can further reduce the amount of calculation of the correlation value calculation unit 18.
- the radar device 1 can further reduce the amount of power consumption based on the reduction of the amount of calculation in the signal processing unit 12.
- the radar device 1 can measure the influence of the wraparound without being measured.
- the measurement range range of discrete time k Rx
- the coherent integration unit 19, the correlation matrix generation unit 20, the distance estimation unit 21, and the arrival direction estimation unit 23 also operate in the same limited measurement range. Therefore, the processing amount of each part can be reduced, and the power consumption in the radar device 1 can be reduced.
- the coherent integrator 19 inputs the sliding correlation value AC (k Rx , M) for each discrete time k Rx output from the correlation value calculator 18. Coherent integrator 19, the M-th transmission period Tr at discrete time k Rx computed sliding correlation value AC for each (k Rx, M) based on the duration of the transmission cycle Tr of a predetermined number of times (Np times) ( Add the sliding correlation value AC (k Rx , M) over Np ⁇ Tr).
- the coherent integration unit 19 adds the sliding correlation value AC (k Rx , M) for each discrete time k Rx over a period (Np ⁇ Tr) of the transmission cycle Tr a predetermined number of times (Np times).
- the m-th coherent integrated value CI (k Rx , m) is calculated according to Formula (6) for each discrete time k Rx .
- Np represents the number of times of coherent integration in the coherent integrator 19.
- m represents the ordinal number of the number of times of coherent integration in the case where the number of times of coherent integration Np of the coherent integration unit of each antenna system processing unit is one unit.
- the coherent integrator 19 outputs the calculated coherent integral value CI (k Rx , m) to the correlation matrix generator 20.
- the coherent integrator 19 suppresses noise components included in the reflected wave signal in a range where the reflected wave signal from the target TAR has a high correlation by adding Np times of the sliding correlation value AC (k Rx , M), Signal to Noise Ratio (SNR) of a wave signal can be improved. Furthermore, since the coherent integrator 19 can improve the reception quality of the reflected wave signal, it can improve the estimation accuracy of the arrival direction of the target TAR.
- the correlation matrix generation unit 20 outputs each coherent integral value CI 1 (k Rx , m),..., CI 4 (k Rx , m) output from the coherent integration unit of each of the antenna system processing units 10, 10a, 10b, 10c.
- the correlation matrix H (k Rx , m) is generated according to equation (7).
- the superscript H is an operator representing complex conjugate transposition.
- the correlation matrix generation unit 20 calculates a correlation matrix B (k Rx ) obtained by averaging Dp correlation matrices according to Equation (8) over a period (Nf ⁇ Tr) of Nf transmission cycles Tr.
- Dp represents the number of correlation matrices to be added and averaged by the correlation matrix generation unit 20 over a period (Nf ⁇ Tr) of Nf transmission cycles Tr, and satisfies Expression (9).
- the correlation matrix generation unit 20 outputs the correlation matrix B (k Rx ) that has been added and averaged to the arrival direction estimation unit 23.
- the correlation matrix generation unit 20 uses the equation (10) instead of the equation (7) to set the reception antenna of one of the plurality of antenna system processors 10, 10a, 10b and 10c as the antenna system processor.
- the correlation vector may be calculated using the phase of the received signal as the reference phase.
- the superscript asterisk (*) represents a complex conjugate operator.
- the distance estimation unit 21 calculates each coherent integral value CI 1 (k Rx , m),..., CI 4 (k Rx , m) output from the coherent integration unit of each of the antenna system processing units 10, 10a, 10b, 10c. input.
- the distance estimation unit 21 calculates a square sum RP (k Rx ) of each of the coherent integration values from the plurality of antenna system processing units 10, 10a, 10b, and 10c based on each of the input coherent integration values. Calculate according to).
- the squared addition value RP (k Rx ) corresponds to the signal level of the reflected wave signal from the target TAR for each discrete time k Rx .
- the distance estimation unit 21 selects a discrete time k Rx in the case where the square addition value RP (k Rx ) becomes equal to or higher than a predetermined value from the ambient noise level of the radar device 1 and selects a target based on the selected discrete time k Rx
- the distance Range (k Rx ) to TAR is calculated according to equation (12).
- Co represents the light velocity
- f RxBB represents the reception reference clock frequency.
- the distance estimation unit 21 outputs the calculated distance Range (k Rx ) to the target TAR to the arrival direction estimation unit 23.
- the direction vector storage unit 22 has predetermined NU and NV ranges within the range of azimuth and elevation angles at which the radar device 1 installed at the installation height H ant estimates the arrival direction of the target TAR.
- the complex response of the array antenna in the case of two-dimensional division is stored.
- the complex response of the array antenna is a direction vector D including azimuth angle component ⁇ u and elevation angle component ⁇ v when the azimuth angle and elevation angle ranges for estimating the arrival direction are divided in two dimensions.
- ⁇ u , ⁇ v u is an integer of 1 or more and NU or less
- v is an integer of 1 or more and NV or less.
- NU and NV are predetermined numbers determined according to the measurement area of the radar device 1.
- the complex response of the array antenna is, for example, measured beforehand in a radio anechoic chamber, and in addition to the phase difference information geometrically calculated at the antenna element spacing between the array antennas, the coupling between the antenna elements between the array antennas, and the amplitude and It includes deviation information including each phase error.
- the arrival direction estimation unit 23 receives the correlation matrix B (k Rx ) output from the correlation matrix generation unit 20 and the distance Range (k Rx ) to the target output from the distance estimation unit 21. Arrival direction estimation unit 23 is based on input correlation matrix B (k Rx ), distance Range to the target Range (k Rx ), and direction vector D ( ⁇ u , ⁇ v ) stored in direction vector storage unit 22. Then, estimate the arrival direction of the target TAR.
- FIG. 7 is a flow chart for explaining the operation of the arrival direction estimation unit 23 of the first embodiment.
- the arrival direction estimation unit 23 sets the discrete time k Rx as the start time of the measurement period in the radar device 1 (S11). Based on the distance Range (k Rx ) to the target TAR, the installation height H ant of the radar antenna RA, and the inclination angle ⁇ 0 of the radar antenna RA in the elevation angle direction, the arrival direction estimation unit 23 Calculate k Rx ) (S12). The elevation angle ⁇ (k Rx ) with respect to the target TAR is calculated by equation (13).
- ⁇ (k Rx ) represents the elevation angle from the radar antenna RA to the bottom of the target TAR, based on the direction of the inclination angle ( ⁇ 0 ) of the radar antenna RA.
- ⁇ b represents the angle between the bottom of the target TAR and the radar antenna RA, which is geometrically determined by the distance Range (k Rx ) to the target TAR and the installation height H ant, and is calculated according to equation (14).
- ⁇ b > 0 and ⁇ 0 ⁇ 0.
- Arrival direction estimation unit 23 fixes the elevation angle component of direction vector D ( ⁇ u , ⁇ v ) stored in direction vector storage unit 22 to the elevation angle ⁇ (k Rx ) with respect to target TAR calculated in step S12. Do.
- the arrival direction estimation unit 23 uses the direction vector D ( ⁇ u , ⁇ (k Rx )) that makes the azimuth angle component variable, to evaluate the evaluation function value P [D ( ⁇ u , ⁇ (k) of the arrival direction of the target TAR. Rx )), k Rx ] are calculated according to the equation (15) (S13).
- evaluation function values P [D ( ⁇ u , ⁇ (k Rx )), k Rx ] are known according to the arrival direction estimation algorithm, and in each embodiment including the present embodiment, for example, the following reference non-patent
- the evaluation function value of the beamformer method using the array antenna disclosed in Document 1 is used.
- the superscript H is a Hermite transpose operator.
- the Capon method or the MUSIC method may be used.
- the arrival direction estimation unit 23 determines the azimuthal angle component ⁇ u in the case where the evaluation function value P [D ( ⁇ u , ⁇ (k Rx )), k Rx ] calculated in step S 13 is the maximum value, Calculate according to).
- the arrival direction estimation unit 23 determines the azimuth angle component ⁇ u in the case where the evaluation function values P [D ( ⁇ u , ⁇ (k Rx )), k Rx ] become maximum values, the arrival direction DOA of the target TAR (k Rx ) (S14).
- arg max P (x) is an operator that takes as an output value a value in a domain where the function value P (x) is maximum.
- the arrival direction estimation unit 23 ends the operation when the discrete time k Rx is at the end of the measurement period of the radar device 1 (S15, YES). On the other hand, when the discrete time k Rx is not at the end of the measurement period of the radar device 1 (S15, NO), the arrival direction estimation unit 23 increments the discrete time k Rx (S16), and the next discrete time k Rx Repeat steps S12 to S14.
- the radar device 1 first calculates the distance Range (k Rx ) to the target TAR, which can be measured relatively accurately, compared to the calculation of the azimuth angle component, and the direction vector D ( ⁇ u , ⁇ ). Determine (fix) the elevation component of v ). Furthermore, the radar device 1 fixes the elevation angle component, and uses an orientation vector D ( ⁇ u , ⁇ (k Rx )) that makes the azimuth angle component variable, to use an evaluation function value P [D (D) for direction of arrival estimation. ⁇ u , ⁇ (k Rx )), k Rx ] are calculated, and the azimuth angle component in the case of giving the evaluation function value which becomes the maximum value is determined as the arrival direction of the target TAR.
- the radar device 1 reduces the amount of calculation for estimating the direction of arrival of the reflected wave signal from the target, and depends on the azimuth angle direction ⁇ and the elevation angle direction ⁇ , and generates amplitude and phase among the receiving antenna elements. Since the arrival direction is estimated using the deviation information, the estimation accuracy of the arrival direction can be improved.
- the radar transmitter Tx has one transmission antenna Tx-ant in this embodiment, the radar transmitter Tx has an array antenna having a configuration including a plurality of transmitter antennas as the radar receiver Rx. You may The radar transmitter Tx can vary the directivity of the radar transmission signal using an array antenna.
- Arrival direction estimation unit 23 determines evaluation function value P based on the range of a predetermined azimuth component or elevation component determined in accordance with the directivity of the radar transmission signal in direction vector D ( ⁇ u , ⁇ v ).
- the maximum value of [D ( ⁇ u , ⁇ (k Rx )), k Rx ] is calculated, and the azimuth angle component of the direction vector in the evaluation function value that becomes the maximum value is determined as the arrival direction.
- the radar transmitting unit Tx may have an array antenna having a configuration including a plurality of transmitting antennas in the same manner as the radar receiving unit Rx, which can be similarly applied to the following embodiments.
- FIG. 15 is a block diagram showing in detail the internal configuration of a radar device 1m according to a modification of the first embodiment.
- the radar device 1m shown in FIG. 15 has a configuration in which two transmitting antennas Tx-ant1 and Tx-ant2, an antenna switching portion Ancg, and an antenna switching control portion Anct are further added to the configuration of the radar transmission portion Tx shown in FIG. Have.
- the antenna switching control unit Anct outputs a switching control signal to select one of the plurality of transmission antennas Tx-ant1 and Tx-ant2 alternatively.
- the antenna switching unit Ancg switches the antenna that transmits the radar transmission signal based on the switching control signal from the antenna switching control unit Anct.
- the transmitting antennas Tx-ant1 and Tx-ant2 have different detection ranges in the transmitting antennas Tx-ant1 and Tx-ant2 with different depression angles in the vertical plane of the main beam direction of the radar transmission signal shown in FIG. Do.
- the transmit antennas Tx-ant1 and Tx-ant2 may have different vertical plane beam widths.
- the arrival direction estimation unit 23 transmits the radar transmission signal to the transmitting antennas Tx-ant1 and Tx-ant2 based on the switching control signal from the antenna switching control unit Anct in the direction vector D ( ⁇ u , ⁇ v ).
- the maximum value of evaluation function values P [D ( ⁇ u , ⁇ (k Rx )), k Rx ] is calculated based on the range of elevation angle components according to different distance ranges, and the direction in the evaluation function value that becomes the maximum value.
- the azimuthal component of the vector is determined as the direction of arrival. Thereby, the amount of calculations in the radar receiver Rxm of the radar device 1m can be further reduced.
- the radar transmitting unit Tx may have an array antenna having a configuration including a plurality of transmitting antennas in the same manner as the radar receiving unit Rxm, which can be similarly applied to the following embodiments.
- FIG. 8 is a diagram for explaining the possibility that the elevation component of the direction vector differs and the estimation accuracy of the arrival direction is degraded depending on the height of the target TAR present at a short distance.
- the target TAR calculated respectively from the reflected wave signal from the top of the target TAR and the reflected wave signal from the bottom of the target TAR It is necessary to consider the difference in distance to the end.
- the distance estimation error of the radar device tends to occur, and the arrival direction of the target TAR is estimated in order to estimate the arrival direction depending on the elevation direction ⁇ and without correctly using the amplitude and phase deviation information generated between the receiving antenna elements. Also the estimation accuracy of
- the arrival direction estimation unit uses the distance Range (k Rx ) to the target TAR calculated by the distance estimation unit to consider the elevation height component ⁇ with respect to the target TAR in consideration of the ground height H target of the target TAR. Calculate the range of k Rx ) (see FIG. 9).
- FIG. 9 is an explanatory view of a straight line in the tilt angle ( ⁇ 0 ) direction of the radar antenna of the radar device in the second embodiment and an elevation angle ⁇ (k Rx ) with respect to the target.
- the configuration of the radar device of the present embodiment is the same as that of the radar device 1 of the first embodiment, so the description of the configuration of the radar device of the present embodiment is omitted, and the operation different from that of the radar device 1 of the first embodiment Will be described.
- reference numerals of each part of the radar device 1 of the first embodiment are used for convenience.
- FIG. 10 is a flowchart for explaining the operation of the arrival direction estimation unit 23 of the second embodiment.
- the arrival direction estimation unit 23 sets the discrete time k Rx as the start time of the measurement period in the radar device 1 (S21).
- the arrival direction estimation unit 23 determines the distance Range (k Rx ) to the target TAR, the installation height H ant of the radar antenna RA, the ground height H target of the assumed target TAR, and the tilt angle ⁇ in the elevation angle direction of the radar antenna RA.
- the elevation angle ⁇ (k Rx ) with respect to the target TAR is calculated (S22).
- the elevation angle ⁇ (k Rx ) with respect to the target TAR is in the range shown in Formula (17).
- phi (k Rx) from elevation from radar antenna RA in the case where with respect to the direction of inclination of the radar antenna RA (phi 0) to the bottom of the target TAR, based on the direction of inclination of the radar antenna RA (phi 0) Represents the range from the radar antenna RA to the elevation angle of the top of the target TAR.
- ⁇ b is geometrically determined by the distance Range (k Rx ) to the target TAR and the installation height H ant, and represents the elevation angle between the bottom of the target TAR and the radar antenna RA, and is calculated by Equation (14).
- ⁇ bt is geometrically determined by the distance Range (k Rx ) to the target TAR, the installation height H ant and the ground height H target of the target TAR, and represents the elevation angle between the bottom of the target TAR and the radar antenna RA, Calculated by (14).
- the arrival direction estimation unit 23 sets the elevation angle component of the direction vector D ( ⁇ u , ⁇ v ) stored in the direction vector storage unit 22 to the range of the elevation angle ⁇ (k Rx ) with respect to the target TAR calculated in step S22. Variable in The arrival direction estimation unit 23 uses the set elevation angle component range and the direction vector D ( ⁇ u , ⁇ (k Rx )) that makes the azimuth angle component range variable, to evaluate the evaluation function value P of the arrival direction of the target TAR.
- the arrival direction estimation unit 23 determines the azimuthal angle component ⁇ u in the case where the evaluation function value P (D ( ⁇ u , ⁇ (k Rx ), k Rx ) calculated in step S 23 is the maximum value, The arrival direction estimation unit 23 calculates the azimuth component ⁇ u in the case where the evaluation function value P (D ( ⁇ u , ⁇ (k Rx ), k Rx ) becomes the maximum value, as the arrival direction DOA of the target TAR. It is determined that (k Rx ) (S24).
- the arrival direction estimation unit 23 ends the operation when the discrete time k Rx is at the end of the measurement period of the radar device 1 (S25, YES). On the other hand, when the discrete time k Rx is not at the end of the measurement period of the radar device 1 (S25, NO), the arrival direction estimation unit 23 increments the discrete time k Rx (S26), and the next discrete time k Rx Repeat steps S22 to S24.
- the radar device 1 uses the distance Range (k Rx ) to the target TAR calculated by the distance estimation unit to consider the ground height H target of the assumed target TAR with respect to the target TAR.
- the range of elevation component ⁇ (k Rx ) is calculated.
- the radar device 1 estimates the arrival direction of the target TAR in the same manner as the first embodiment, using the range of the elevation angle component ⁇ (k Rx ) with respect to the target TAR.
- the radar apparatus 1 of the present embodiment can estimate the arrival direction of the target TAR in consideration of the ground height H target of the target TAR. That is, compared with the radar device 1 according to the first embodiment, the radar device 1 according to the present embodiment depends on the elevation direction ⁇ even when the target TAR is present at a short distance, and generates amplitude between the receiving antenna elements and Since the phase deviation information is correctly used to estimate the direction of arrival, the estimation accuracy of the direction of arrival of the target TAR can be improved.
- the arrival direction estimation unit 23 varies the elevation angle component of the evaluation function value, that is, the range of elevation angle ⁇ (k Rx ) with respect to the target TAR based on the maximum value of the ground height H target of the target TAR assumed in advance.
- the maximum value of the evaluation function values may be calculated.
- the arrival direction estimation unit 23 can use a range in which the ground height H target of the target TAR is assumed in advance, and the amount of calculation of the evaluation function value can be further reduced.
- the arrival direction estimation unit 23 varies the elevation angle component ⁇ (k Rx ) with respect to the target TAR according to the distance range of the target TAR, ie, the distance from the radar antenna RA, and calculates the maximum value of the evaluation function value.
- FIG. 11 is an explanatory view of a range of elevation angle components of evaluation function values determined according to the distance range, and FIG. 11 (a) is a target existing at a short distance, and FIG. It is an existing target.
- the arrival direction estimation unit 23 performs the target TAR as compared with the case where the target TAR is present at a long distance from the radar antenna RA.
- the arrival direction estimation unit 23 performs the target TAR as compared to the case where the target TAR exists at a short distance from the radar antenna RA.
- the range of the elevation angle component ⁇ (k Rx ) with respect to is relatively narrowed.
- the arrival direction estimation unit 23 can change the range of the elevation component ⁇ (k Rx ) with respect to the target TAR according to the distance Range (k Rx ) from the radar antenna RA to the target TAR, and the calculation amount of the evaluation function value Can be further reduced.
- the arrival direction estimating unit 23 determines that the target TAR is present at a long distance, and when the distance is less than the predetermined threshold.
- the target TAR may be determined to be at a short distance.
- the direction vector D ( ⁇ u , ⁇ v ) stored in the direction vector storage unit 22 is measured and calculated in advance in a radio anechoic chamber, and is a fixed value.
- the operation state for estimating the distance and the arrival direction in the first or second embodiment is a measurement mode
- the operation state for measuring and updating a direction vector is a calibration mode
- the mode is switched to one of the modes. .
- FIG. 12 is a block diagram showing in detail the internal configuration of the radar device 1s of the third embodiment.
- the same reference numerals are given to the same portions as the radar device 1 of the first embodiment, and the descriptions of the same portions are omitted. The operation different from that of the device 1 will be described.
- the radar device 1s is installed at a predetermined height H ant from the ground GND, similarly to the radar device 1 of the first or second embodiment.
- the radar device 1s shown in FIG. 12 is configured to include a reference signal oscillator Lo, a radar transmitter Tx, and a radar receiver Rxs.
- the configuration of the radar transmitter Tx is the same as that of the radar transmitter Tx according to the first or second embodiment, and thus the description thereof will be omitted.
- the reference signal oscillator Lo is connected to the radar transmitter Tx and the radar receiver Rxs, and supplies a signal from the reference signal oscillator Lo to the radar transmitter Tx and the radar receiver Rxs in common, thereby enabling the radar transmitter Tx and the radar Synchronize the processing of the reception unit Rxs.
- the radar receiver Rxs includes four antenna system processors 10, 10a, 10b and 10c, a mode controller 24, a switch 25, a direction vector calculator 26, a correlation matrix generator 20s, a distance estimator 21s, and a direction vector memory.
- the configuration includes a unit 22s and an arrival direction estimation unit 23s.
- the radar receiver Rxs shown in FIG. 12 has four antenna system processors, but the number of antenna system processors is not limited to four and may be two or more.
- the mode control unit 24 outputs a switching signal to one of the measurement mode for estimating the distance and the arrival direction of the target TAR, and the calibration mode for measuring and updating the direction vector to the switching unit 25.
- the target TAR for calibration is placed at the point Z (distance R cal ) at a known position, and the directional vector D cal ( ⁇ cal , ⁇ at the azimuth angle component ⁇ cal and elevation angle component ⁇ cal of the point Z cal ) is measured.
- the direction vector D ( ⁇ u , ⁇ v ) at the azimuth angle component ⁇ cal and elevation angle component ⁇ cal of the point Z already stored in the direction vector storage unit 22 is measured. It is updated to cal ( ⁇ cal , ⁇ cal ).
- the mode control unit 24 sets the azimuth angle component ⁇ cal and elevation angle component ⁇ cal of the point Z with respect to the calibration target TAR disposed at the point Z (distance R cal ) at a known position.
- a control signal that causes the direction vector D cal ( ⁇ cal , ⁇ cal ) to be measured is output to the direction vector calculation unit 26.
- the control signal for measuring the direction vector D cal ( ⁇ cal , ⁇ cal ) includes each information of the discrete time k cal , the azimuth component ⁇ cal and the elevation angle ⁇ cal .
- the mode control unit 24 instructs the direction vector computing unit 26 to control the direction vector storage unit 22 s to update the direction vector D cal ( ⁇ cal , ⁇ cal ) measured at the point Z (distance R cal ) at a known position. Output.
- the switching unit 25 selects the output destination of each coherent integral value from the plurality of antenna system processing units 10, 10a, 10b, and 10c according to the correlation matrix generation unit 20s or the direction according to the switching signal output from the mode control unit 24. It switches to the vector operation part 26s. Specifically, the switching unit 25 outputs the respective coherent integral values from the plurality of antenna system processing units 10, 10a, 10b, and 10c to the correlation matrix generation unit 20s in the measurement mode. The switching unit 25 outputs the coherent integrated values from the plurality of antenna system processing units 10, 10a, 10b, and 10c to the direction vector calculation unit 26 in the calibration mode.
- Direction vector operation unit 26 sets discrete time k cal and azimuth angle component ⁇ cal based on the control signal output from mode control unit 24 at calibration target TAR disposed at point Z (distance R cal ).
- a direction vector D cal ( ⁇ cal , ⁇ cal ), which is phase difference information with respect to the reference antenna at the elevation angle ⁇ cal is calculated according to equation (19).
- the direction vector computing unit 26 stops its operation in the measurement mode.
- Ra represents the number of the reference antenna, and is any one of the plurality of receiving antennas Rx-ant1 to Rx-ant4.
- Ncal represents the number of transmission cycles (Ncal ⁇ Tr) in which the calibration mode is performed.
- the superscript asterisk (*) in equation (19) represents a complex conjugate operator.
- Direction vector calculation unit 26 based on the control signal outputted from the mode control unit 24, the direction vector D at an azimuth angle component theta cal and elevation component phi cal stored in the direction vector storage unit 22s ( ⁇ cal, ⁇ Cal ) is updated to the direction vector D cal ( ⁇ cal , ⁇ cal ) calculated at the discrete time k cal .
- the mode control unit 24 changes the azimuth angle component ⁇ cal and elevation angle component ⁇ cal of the point Z at predetermined intervals with respect to the calibration target TAR disposed at the point Z (distance R cal ) at a known position.
- the switching unit 25 and the direction vector computing unit 26 perform calibration, that is, update of the direction vector in the measurement area of the radar device 1s.
- the radar device 1s of the present embodiment operates in the measurement mode in the same manner as the radar device 1 of the first or second embodiment.
- the radar device 1s sets the azimuth angle component ⁇ cal and elevation angle component ⁇ cal of the point Z at predetermined intervals with respect to the calibration target TAR disposed at the point Z (distance R cal ) at a known position. Calibration is performed in the measurement area of the radar device 1 s by changing each time.
- the radar device 1s can easily switch between the measurement mode and the calibration mode under the environment where the radar device 1s is installed. Furthermore, the radar device 1s can update the direction vector corresponding to the azimuth angle component and the elevation angle component stored in the direction vector storage unit 22s in the calibration mode. Therefore, the radar device 1s can correct the direction vector even when the deviation (amplitude, deviation of the phase) between the array antennas (a plurality of receiving antennas) is caused by the temporal change, and the time accuracy of the estimation accuracy of the arrival direction of the radar device 1s Deterioration can be prevented.
- FIG. 17 is a block diagram showing in detail the internal configuration of a radar device 1 n according to a modification of the third embodiment.
- the radar apparatus 1n shown in FIG. 17 has a configuration in which two transmitting antennas Tx-ant1 and Tx-ant2, an antenna switching unit Ancg, and an antenna switching control unit Anct are further added to the configuration of the radar transmission unit Tx shown in FIG. Have.
- the antenna switching control unit Anct outputs a switching control signal to select one of the plurality of transmission antennas Tx-ant1 and Tx-ant2 alternatively.
- the antenna switching unit Ancg switches the antenna that transmits the radar transmission signal based on the switching control signal from the antenna switching control unit Anct.
- the transmitting antennas Tx-ant1 and Tx-ant2 have different detection ranges in the transmitting antennas Tx-ant1 and Tx-ant2 with different depression angles in the vertical plane of the main beam direction of the radar transmission signal shown in FIG. Do.
- the transmit antennas Tx-ant1 and Tx-ant2 may have different vertical plane beam widths.
- the arrival direction estimation unit 23s transmits the radar transmission signal to the transmission antennas Tx-ant1 and Tx-ant2 based on the switching control signal from the antenna switching control unit Anct in the direction vector D ( ⁇ u , ⁇ v ).
- the maximum value of evaluation function values P [D ( ⁇ u , ⁇ (k Rx )), k Rx ] is calculated based on the range of elevation angle components according to different distance ranges, and the direction in the evaluation function value that becomes the maximum value.
- the azimuthal component of the vector is determined as the direction of arrival. Thereby, the amount of calculations in the radar receiver Rxn of the radar device 1 n can be further reduced.
- the present disclosure is useful as a radar device that improves the direction estimation accuracy of each target even if the Doppler frequency of the signal of each reflected wave from each target is the same when there are multiple targets within the range resolution.
Abstract
Description
先ず、本開示に係るレーダ装置の各実施形態を説明する前に、各実施形態の内容に至る経緯について、図面を参照して説明する。
第1の実施形態のレーダ装置1を、図1~図5を参照して説明する。図1は、第1の実施形態におけるレーダ装置1のレーダアンテナの傾角(φ0)方向の直線と、ターゲットに対する仰角φ(kRx)との説明図である。以下の説明では、本実施形態のレーダ装置1の送信アンテナTx-ant及び複数の受信アンテナRx-ant1~Rx-ant4を総括してレーダアンテナRAといい、複数の受信アンテナRx-ant1~Rx-ant4はアレーアンテナを形成している。説明を簡単にするために、図1ではレーダ装置1のうちレーダアンテナRAを図示している。
次に、レーダ受信部Rxの各部の構成を、図3を参照して説明する。
なお、第1の実施形態ではレーダ送信部Txが1個の送信アンテナTx-antを有するとしたが、レーダ送信部Txが複数の送信アンテナを有し、いずれかのアンテナに切り換えても良い。図15は、第1の実施形態の変形例のレーダ装置1mの内部構成を詳細に示すブロック図である。
図8は、近距離に存在するターゲットTARの高さに応じて、方向ベクトルの仰角成分が異なり到来方向の推定精度が劣化する可能性を説明するための図である。レーダ装置から比較的近距離に存在するターゲットTARの高さ(地上高)が高いと、ターゲットTARの頂部からの反射波信号とターゲットTARの底部からの反射波信号とによりそれぞれ演算されたターゲットTARまでの距離の差異を考慮する必要がある。
第1又は第2の実施形態では、方向ベクトル記憶部22に記憶されている方向ベクトルD(θu,φv)は予め電波暗室において測定及び演算されており固定値であった。本実施形態では、第1又は第2の実施形態の距離及び到来方向を推定する動作状態を測定モードとし、方向ベクトルを測定して更新する動作状態をキャリブレーションモードとし、いずれかのモードに切り換える。
なお、第3の実施形態ではレーダ送信部Txが1個の送信アンテナTx-antを有するとしたが、レーダ送信部Txが複数の送信アンテナを有し、いずれかのアンテナに切り換えても良い。図17は、第3の実施形態の変形例のレーダ装置1nの内部構成を詳細に示すブロック図である。
2、2r 送信信号生成部
3 送信RF部
4 符号生成部
5、5r 変調部
6、6r LPF
7 D/A変調部
8、14 周波数変換部
9、13 増幅器
10、10a、10b、10c アンテナ系統処理部
11 受信RF部
12 信号処理部
15 直交検波部
16、17 A/D変換部
18 相関値演算部
19 コヒーレント積分部
20、20s 相関行列生成部
21、21s 距離推定部
22、22s 方向ベクトル記憶部
23、23s 到来方向推定部
24 モード制御部
25 切換部
26 方向ベクトル演算部
CM 送信符号記憶部
CT3 送信符号制御部
Rx、Rxs レーダ受信部
Tx レーダ送信部
Claims (12)
- 地面から所定の高さの位置に設置されたレーダ装置であって、
送信符号を高周波のレーダ送信信号に変換し、前記所定の高さの位置から前記地面に向かって所定の方向に傾けられた送信アンテナから前記レーダ送信信号を送信するレーダ送信部と、
ターゲットにて反射された前記レーダ送信信号である反射波信号を受信する複数のアンテナ系統処理部を用いて前記ターゲットの到来方向を推定するレーダ受信部と、を含み、
前記レーダ受信部は、
前記複数のアンテナ系統処理部からの各出力を基に、受信アンテナの配置に起因する位相差情報を含む相関行列を生成する相関行列生成部と、
前記複数のアンテナ系統処理部からの各出力を基に、前記ターゲットまでの距離を推定する距離推定部と、
前記距離推定部の出力を基に、前記ターゲットの仰角成分を決定し、方位角成分を可変した方向ベクトルと前記相関行列生成部の出力により、前記ターゲットの到来方向を推定する到来方向推定部と、を有するレーダ装置。 - 請求項1に記載のレーダ装置であって、
前記方向ベクトルは、方位角方向及び仰角方向に依存し、且つ前記複数のアンテナ系統処理部間において生じる振幅及び位相の偏差情報を含むレーダ装置。 - 請求項1又は2に記載のレーダ装置であって、
前記アンテナ系統処理部は、
受信信号と前記送信符号との相関値を算出する相関演算部と、
所定のコヒーレント積分数を用いてコヒーレント積分するコヒーレント積分部と、を有するレーダ装置。 - 請求項3に記載のレーダ装置であって、
前記複数のアンテナ系統処理部は、それぞれ、
前記反射波信号を受信する受信アンテナと、
前記受信された受信信号をベースバンドに変換する受信RF部と、
前記ベースバンドに変換された受信信号を、デジタルデータに変換するA/D変換部と、を有するレーダ装置。 - 請求項1~4のうちいずれか一項に記載のレーダ装置であって、
前記距離推定部は、
前記複数のアンテナ系統処理部からの各コヒーレント積分の各出力の自乗加算値を演算し、前記レーダ装置の周囲雑音レベルから所定値以上となる前記自乗加算値を基に、前記ターゲットまでの距離を演算するレーダ装置。 - 請求項1~5のうちいずれか一項に記載のレーダ装置であって、
前記複数のアンテナ系統処理部の各受信アンテナは、前記所定の高さの位置から前記地面に向かって所定の方向に傾けられ、
前記到来方向推定部は、
前記ターゲットまでの距離と、前記所定の高さと、前記送信アンテナ及び複数の前記受信アンテナの傾角とを基に、前記所定の方向を基準とした場合の前記送信アンテナから前記ターゲットへの仰角成分を演算するレーダ装置。 - 請求項6に記載のレーダ装置であって、
前記到来方向推定部は、
前記演算された仰角成分を、前記方向ベクトルにおける前記仰角成分として用いて、前記到来方向の評価関数値を演算するレーダ装置。 - 請求項1~5のうちいずれか一項に記載のレーダ装置であって、
前記複数のアンテナ系統処理部の各受信アンテナは、前記所定の高さの位置から前記地面に向かって所定の方向に傾けられ、
前記到来方向推定部は、
前記ターゲットまでの距離と、前記所定の高さと、前記ターゲットの高さと、前記送信アンテナ及び複数の前記受信アンテナの傾角とを基に、前記所定の方向を基準とした場合の前記送信アンテナから前記ターゲットの頂部の仰角成分から前記送信アンテナから前記ターゲットの底部の仰角成分までの範囲を演算するレーダ装置。 - 請求項8に記載のレーダ装置であって、
前記到来方向推定部は、
前記演算された仰角方向の範囲を、前記方向ベクトルにおける前記仰角成分の範囲として用いて、前記到来方向の評価関数値を演算するレーダ装置。 - 請求項7又は9に記載のレーダ装置であって、
前記到来方向推定部は、
前記演算された前記評価関数値の最大値を演算し、前記最大値となる前記評価関数値における前記方向ベクトルの前記方位角成分を、前記到来方向として判定するレーダ装置。 - 請求項1~10のうちいずれか一項に記載のレーダ装置であって、
前記レーダ受信部は、
前記ターゲットの距離及び到来方向を推定する測定モードと、前記方向ベクトルを更新するキャリブレーションモードとのうちいずれかのモードへの切換信号を出力するモード制御部と、
前記キャリブレーションモードではキャリブレーション用の既知の位置に対する方向ベクトルを演算する方向ベクトル演算部と、
前記切換信号に応じて、前記複数のアンテナ系統処理部からの各コヒーレント積分の各出力の出力先を、前記相関行列生成部又は前記方向ベクトル演算部に切り換える切換部と、を更に有し、
前記方向ベクトル演算部は、
前記既知の位置に対応している方向ベクトルを、前記演算された前記方向ベクトルに更新するレーダ装置。 - 請求項7、9~11のうちいずれか一項に記載のレーダ装置であって、
前記レーダ送信部は、
複数の送信アンテナを用いて前記レーダ送信信号の指向性を可変させ、
前記到来方向推定部は、
前記方向ベクトルのうち所定の方位角成分又は仰角成分の範囲を基に、前記到来方向の評価関数値の最大値を演算し、前記最大値となる前記評価関数値における前記方向ベクトルの前記方位角成分を、前記到来方向として判定するレーダ装置。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013547006A JP6148622B2 (ja) | 2011-12-02 | 2012-11-30 | レーダ装置 |
US14/360,285 US9470784B2 (en) | 2011-12-02 | 2012-11-30 | Radar device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-265020 | 2011-12-02 | ||
JP2011265020 | 2011-12-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013080570A1 true WO2013080570A1 (ja) | 2013-06-06 |
Family
ID=48535058
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/007717 WO2013080570A1 (ja) | 2011-12-02 | 2012-11-30 | レーダ装置 |
Country Status (3)
Country | Link |
---|---|
US (1) | US9470784B2 (ja) |
JP (1) | JP6148622B2 (ja) |
WO (1) | WO2013080570A1 (ja) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104155647A (zh) * | 2014-08-22 | 2014-11-19 | 西安电子科技大学 | 基于机扫米波阵列雷达的估计目标方位角的方法 |
JP2015068700A (ja) * | 2013-09-27 | 2015-04-13 | パナソニック株式会社 | レーダ装置及び物体検出方法 |
JP2015179061A (ja) * | 2014-02-28 | 2015-10-08 | パナソニック株式会社 | レーダ装置 |
JP2017516116A (ja) * | 2014-04-04 | 2017-06-15 | 日本テキサス・インスツルメンツ株式会社 | 駐車アシストレーダーのためのアンテナ構成 |
JP2017173227A (ja) * | 2016-03-25 | 2017-09-28 | パナソニック株式会社 | レーダ装置及びレーダ方法 |
JP2018151313A (ja) * | 2017-03-14 | 2018-09-27 | パナソニック株式会社 | レーダ装置及びレーダ方法 |
JP6793897B1 (ja) * | 2020-03-09 | 2020-12-02 | 三菱電機株式会社 | レーダ信号処理装置、レーダ信号処理方法及びレーダ装置 |
WO2023218632A1 (ja) * | 2022-05-13 | 2023-11-16 | 株式会社日立製作所 | レーダ装置および物標検知方法 |
JP7441807B2 (ja) | 2018-07-20 | 2024-03-01 | 京セラ株式会社 | 電子機器、電子機器の制御方法、及び電子機器の制御プログラム |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6123974B2 (ja) * | 2011-04-15 | 2017-05-10 | パナソニックIpマネジメント株式会社 | レーダ装置 |
WO2013080570A1 (ja) * | 2011-12-02 | 2013-06-06 | パナソニック株式会社 | レーダ装置 |
JP6116126B2 (ja) * | 2012-03-29 | 2017-04-19 | パナソニック株式会社 | レーダ装置 |
WO2014129142A1 (ja) * | 2013-02-21 | 2014-08-28 | パナソニック株式会社 | レーダーシステム |
JP6432221B2 (ja) * | 2014-01-15 | 2018-12-05 | パナソニック株式会社 | レーダ装置 |
US10145871B2 (en) * | 2014-04-29 | 2018-12-04 | Significs And Elements, Llc | Systems and methods for joint angle-frequency determination |
JP2016142661A (ja) * | 2015-02-03 | 2016-08-08 | オプテックス株式会社 | 車両検知装置、車両ゲートシステム、物体検知装置、車用検知装置の制御方法、車両検知プログラム |
US9705511B2 (en) | 2015-06-18 | 2017-07-11 | Yekutiel Josefsberg | Ultra low phase noise frequency synthesizer |
US9831881B2 (en) * | 2015-06-18 | 2017-11-28 | Yekutiel Josefsberg | Radar target detection system for autonomous vehicles with ultra-low phase noise frequency synthesizer |
JP6850173B2 (ja) * | 2017-03-24 | 2021-03-31 | 京セラ株式会社 | 電磁波検出装置、プログラム、および電磁波検出システム |
US10205457B1 (en) | 2018-06-01 | 2019-02-12 | Yekutiel Josefsberg | RADAR target detection system for autonomous vehicles with ultra lowphase noise frequency synthesizer |
US10404261B1 (en) | 2018-06-01 | 2019-09-03 | Yekutiel Josefsberg | Radar target detection system for autonomous vehicles with ultra low phase noise frequency synthesizer |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002099986A (ja) * | 2000-09-22 | 2002-04-05 | Natl Inst For Land & Infrastructure Management Mlit | ミリ波レーダによる走行車両検出方法 |
JP2011137650A (ja) * | 2009-12-25 | 2011-07-14 | Honda Elesys Co Ltd | 電子走査型レーダ装置、受信波方向推定方法及び受信波方向推定プログラム |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0740894B2 (ja) | 1986-08-28 | 1995-05-10 | 太陽化学株式会社 | 保存性の良い煮豆の製造法 |
JP2918024B2 (ja) * | 1996-04-15 | 1999-07-12 | 日本電気株式会社 | 車両軌跡追尾装置 |
JP3623183B2 (ja) | 2001-11-07 | 2005-02-23 | 三菱電機株式会社 | レーダ装置 |
JP3557463B2 (ja) | 2001-12-28 | 2004-08-25 | 防衛庁技術研究本部長 | スーパーリゾリューションアンテナ |
JP2006329912A (ja) | 2005-05-30 | 2006-12-07 | Hitachi Ltd | 物体検知センサ |
US7414567B2 (en) | 2006-12-22 | 2008-08-19 | Intelligent Automation, Inc. | ADS-B radar system |
JP5173623B2 (ja) | 2008-06-19 | 2013-04-03 | パナソニック株式会社 | 無線測距システム及び無線測距方法 |
WO2013080570A1 (ja) * | 2011-12-02 | 2013-06-06 | パナソニック株式会社 | レーダ装置 |
EP3508878A1 (en) * | 2012-03-19 | 2019-07-10 | Panasonic Corporation | Radar device |
JP6116126B2 (ja) * | 2012-03-29 | 2017-04-19 | パナソニック株式会社 | レーダ装置 |
-
2012
- 2012-11-30 WO PCT/JP2012/007717 patent/WO2013080570A1/ja active Application Filing
- 2012-11-30 JP JP2013547006A patent/JP6148622B2/ja not_active Expired - Fee Related
- 2012-11-30 US US14/360,285 patent/US9470784B2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002099986A (ja) * | 2000-09-22 | 2002-04-05 | Natl Inst For Land & Infrastructure Management Mlit | ミリ波レーダによる走行車両検出方法 |
JP2011137650A (ja) * | 2009-12-25 | 2011-07-14 | Honda Elesys Co Ltd | 電子走査型レーダ装置、受信波方向推定方法及び受信波方向推定プログラム |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015068700A (ja) * | 2013-09-27 | 2015-04-13 | パナソニック株式会社 | レーダ装置及び物体検出方法 |
US10126417B2 (en) | 2013-09-27 | 2018-11-13 | Panasonic Corporation | Radar apparatus and object detecting method |
JP2015179061A (ja) * | 2014-02-28 | 2015-10-08 | パナソニック株式会社 | レーダ装置 |
JP2017516116A (ja) * | 2014-04-04 | 2017-06-15 | 日本テキサス・インスツルメンツ株式会社 | 駐車アシストレーダーのためのアンテナ構成 |
CN104155647A (zh) * | 2014-08-22 | 2014-11-19 | 西安电子科技大学 | 基于机扫米波阵列雷达的估计目标方位角的方法 |
US10613195B2 (en) | 2016-03-25 | 2020-04-07 | Panasonic Corporation | Radar apparatus and radar method |
JP2017173227A (ja) * | 2016-03-25 | 2017-09-28 | パナソニック株式会社 | レーダ装置及びレーダ方法 |
CN107229046A (zh) * | 2016-03-25 | 2017-10-03 | 松下电器产业株式会社 | 雷达装置及雷达方法 |
JP2018151313A (ja) * | 2017-03-14 | 2018-09-27 | パナソニック株式会社 | レーダ装置及びレーダ方法 |
JP7441807B2 (ja) | 2018-07-20 | 2024-03-01 | 京セラ株式会社 | 電子機器、電子機器の制御方法、及び電子機器の制御プログラム |
JP6793897B1 (ja) * | 2020-03-09 | 2020-12-02 | 三菱電機株式会社 | レーダ信号処理装置、レーダ信号処理方法及びレーダ装置 |
WO2021181457A1 (ja) * | 2020-03-09 | 2021-09-16 | 三菱電機株式会社 | レーダ信号処理装置、レーダ信号処理方法及びレーダ装置 |
WO2023218632A1 (ja) * | 2022-05-13 | 2023-11-16 | 株式会社日立製作所 | レーダ装置および物標検知方法 |
Also Published As
Publication number | Publication date |
---|---|
JP6148622B2 (ja) | 2017-06-14 |
US20140327567A1 (en) | 2014-11-06 |
US9470784B2 (en) | 2016-10-18 |
JPWO2013080570A1 (ja) | 2015-04-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6148622B2 (ja) | レーダ装置 | |
US10890652B2 (en) | Radar apparatus | |
JP6818541B2 (ja) | レーダ装置および測位方法 | |
JP6035165B2 (ja) | レーダ装置 | |
US9618616B2 (en) | Radar apparatus | |
US9234956B2 (en) | Radar device | |
US9500741B2 (en) | Radar apparatus | |
US9759806B2 (en) | Radar apparatus | |
JP6105473B2 (ja) | レーダ装置 | |
US10955542B2 (en) | Radar apparatus and direction-of-arrival estimation device | |
JP2016151425A (ja) | レーダ装置 | |
JP2018146443A (ja) | レーダ装置及びレーダ方法 | |
EP2600170A1 (en) | Radar apparatus | |
EP3208632B1 (en) | Radar apparatus and radar method | |
US20220003835A1 (en) | Radar apparatus and method for determining range side lobe | |
JP2021513657A (ja) | 自動車用の角度分解型で広帯域のレーダセンサ | |
JP2012181109A (ja) | レーダ装置 | |
JP2016151424A (ja) | レーダ装置 | |
JP6688977B2 (ja) | レーダ装置 | |
JP2019174206A (ja) | 信号処理装置、信号処理方法及び信号処理プログラム | |
US20230032458A1 (en) | Communication device and communication method | |
JP2012154640A (ja) | レーダ装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12852520 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013547006 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14360285 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12852520 Country of ref document: EP Kind code of ref document: A1 |