JP2019120613A - Rader system, method of controlling rader system, and program - Google Patents

Abstract

To remove a distance side lobe generated by a Doppler shift from a signal for detecting a body without requiring complex constitution nor computation.SOLUTION: A radar device is configured to: generate a first code and a second code which constitute complementary codes; transmit a transmission signal generated by modulating the first code and second code to each other and then putting them together; receive as a reception signal the transmission signal having been reflected by an object; calculate a first correlation value indicative of a correlation value between the reception signal and the first code and a second correlation value indicative of a correlation value between the reception signal and a code based upon the second code; and perform detection processing on the object based upon the first correlation value and the second correlation value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radar device, a control method of the radar device, and a program.

  The radar apparatus is an apparatus that transmits an electric wave (transmission signal) and receives an electric wave (reception signal) reflected by the object to perform detection of the object and measurement of the position. In the radar apparatus, one of the factors determining the performance and characteristics of the radar apparatus is the modulation method of the transmission signal. For example, in the pulse compression method among the modulation methods of the transmission signal, the transmission signal generated using the transmission code is transmitted, and an object obtained from the correlation value between the reception signal reflected back to the object and the transmission code From the detection signal, it is possible to detect an object and measure its position. According to this pulse compression method, it is possible to avoid interference due to external radio waves having a low correlation with the transmission code.

  However, when using a code in which a distance sidelobe (a signal appearing other than the position corresponding to the position of the object in the autocorrelation function) is used as the transmission code, detection of the object may fail. That is, when such a code is used, the object detection signal by the former object is the distance side of the object detection signal by the latter object when the object with small reflection intensity exists in the vicinity of the object with large reflection intensity. It may be buried in the robe.

Therefore, a code composed of a plurality of codes, called a complementary code, is often used as a transmission code for avoiding distance side lobes. For example, for a complementary code consisting of the code A and the code B, the i-th element of the code A and the code B is represented as A _i and B _i respectively. At this time, autocorrelation values R _AA (t) and R _BB (t) at times t of A and B are expressed as follows.

つまり、距離サイドローブが０となり、相関値の和のピークの位置から、物体のレーダ装置からの距離を算出することができる。 Each of the two autocorrelation values has a distance side lobe, but when the sum of these correlation values (object detection signal) is determined, the following characteristics are exhibited.

That is, the distance side lobe becomes 0, and the distance from the radar apparatus of the object can be calculated from the position of the peak of the sum of the correlation values.

つまり、自己相関値Ｒ_ＡＡとＲ_ＢＢはそれぞれメインピークとして４、距離サイドローブとして＋１もしくは−１を有することが分かる。 As an example, when the complementary code A = (1, -1, -1, -1) and the complementary code B = (1, 1, -1, 1), the autocorrelation values R _AA and R _BB are as follows: Is represented by

That is, it can be seen that the autocorrelation values R _AA and R _BB have 4 as the main peak and +1 or -1 as the distance side lobe, respectively.

となり、距離サイドローブが０となることが分かる。このような、自己相関値の和の距離サイドローブが０となる相補符号を送信符号として用いることで、距離サイドローブの発生を回避して、物体の距離を算出することが可能となる。 On the other hand, when the sum of autocorrelation values R _AA and R _BB is obtained,

It can be seen that the distance side lobe is zero. By using such a complementary code in which the distance side lobe of the sum of autocorrelation values is 0 as the transmission code, it is possible to calculate the distance of the object while avoiding the occurrence of the distance side lobe.

Also, based on the known complementary code, a complementary code having a larger number of elements can be obtained. For example, the complementary code C and the complementary code D can be obtained from the following equations using the code A and the code B that constitute the complementary code.

  Thus, the complementary code is composed of a plurality of codes, and has the property that the cross correlation value between the codes is not zero. Therefore, when using code A and code B that make up a complementary code as a transmission code, transmit code A and code B as transmission signals with a fixed interval, and transmit each transmission signal reflected by an object as a reception signal. Need to receive in split. Such time division transmission / reception causes a problem when an object to be detected moves. In other words, when the object is moving, the transmission signal is subject to Doppler shift, which causes a phase difference in the reception signal for each code, and as a result, the sum of correlation values (object detection signal) A distance side lobe will occur.

と求まる。また、算出される自己相関値の和は、

となる。（数７）から、αが０でないために距離サイドローブが０でないことが分かる。 The generation of the distance side lobe will be specifically described. Assuming that the moving speed of the object to be detected is v, the code transmission cycle is T _PRI , and the transmission radio wave wavelength λ, the phase difference (phase change amount) α is

It is determined. Also, the sum of autocorrelation values calculated is

It becomes. From equation (7), it can be seen that the distance side lobe is not zero because α is not zero.

  Several methods have been proposed as methods of suppressing the occurrence of distance side lobes accompanying movement of an object to be detected. For example, Doppler shift is obtained by acquiring received signals in time series, calculating the Doppler shift from phase time change of the reflected signal from the object, and correcting it, or determining the appropriate order of complementary code, in-code bit string reordering operation, etc. There is a method (Non-patent document 1) to suppress the influence of

E. Spano "Complementary sequences with high sidelobe suppression factors for ST / MST radar applications" IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 34 (1996)

  In the prior art described above, when performing the Doppler shift correction processing, the amount of operation processing increases for the Doppler shift calculation and the correction thereof, and the computer performance is required. In addition, when it is desired to increase the distance sidelobe attenuation amount by a method of determining an appropriate code string, it is necessary to transmit and receive more codes in an appropriate order, so problems such as increase in measurement time and processing time are required. There is.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to remove a distance side lobe generated by a Doppler shift with respect to a signal for detecting an object without requiring a complicated configuration or calculation.

  As one means for achieving the above object, the radar device of the present invention has the following configuration. That is, first generation means for generating a first code and a second code, which constitute a complementary code, and combining after modulation for each of the first code and the second code Transmitting means for transmitting a transmission signal generated thereby, receiving means for receiving the transmission signal reflected from the object as a reception signal, and a first value indicating a correlation value between the reception signal and the first code. Calculating means for calculating a second correlation value indicating a correlation value of the correlation value between the received signal and the code based on the second code; and the first correlation value calculated by the calculating means And detection means for detecting the object based on the second correlation value.

  According to the present invention, it is possible to remove distance side lobes generated by Doppler shift with respect to a signal for detecting an object without requiring complicated configuration or calculation.

It is a block diagram explaining the composition of radar installation 101 in a 1st embodiment. It is a figure explaining the code | symbol transmission timing in 1st Embodiment. It is a figure which the analog beam forming antenna in 1st Embodiment transmits an irradiation radio wave, and scans an electric power transmission angle. It is a block diagram of radar installation 101 which has a digital beam forming antenna in a 1st embodiment. It is a block diagram explaining an internal configuration of radar installation 101 in a 2nd embodiment.

  Hereinafter, the present invention will be described in detail based on an example of the embodiment with reference to the attached drawings. In addition, the structure shown in the following embodiment is only an example, and this invention is not limited to the illustrated structure.

First Embodiment
[Configuration of radar device]
FIG. 1 shows the configuration of the radar device 101 according to the first embodiment. The radar apparatus 101 generally includes a transmitting unit 1021, a receiving unit 1022, an analyzing unit 1023, a control unit 1024, and an output unit 1025.

  The transmission unit 1021 generates, modulates, and transmits a transmission code. In the transmission unit 1021, the code generation unit 103, the DA conversion unit 104, and the modulation unit 105 are configured as a pair. First, the code generation unit 103 alternately generates two codes (code A and code B) constituting a complementary code at a fixed time interval (hereinafter, code transmission cycle). A DA (digital-analog) converter 104 converts the code generated by the code generator 103 into an analog signal. The modulation unit 105 modulates the analog signal obtained by the DA conversion unit 104 using two signals output from the local oscillator 109 via the phase shifter 110. The addition unit 106 combines the two signals obtained by the modulation unit 105 to generate a sum signal. The transmission RF unit 107 performs intensity adjustment and unnecessary frequency band signal filtering on the sum signal obtained by the addition unit 106, and the transmission antenna 108 outputs (transmits) the signal obtained by the transmission RF unit 107 as a radio wave. Do. The radio wave (transmission signal) output from the transmission antenna 108 is applied to the object 100 which is an object to be detected. Although the transmission antenna 108 is illustrated as a single antenna in FIG. 1, it may be an array antenna such as a phased array antenna, and various other forms such as an omnidirectional antenna, a horn antenna, and a lens antenna are assumed. Be done.

  The reception unit 1022 performs reception processing of the signal transmitted from the transmission unit 1021. In the reception unit 1022, the demodulation unit 113 and the AD conversion unit 114 are configured as a pair. First, the reception RF unit 112 receives, as a reception signal, the radio wave output from the transmission antenna 108 and reflected by the object 100 via the reception antenna 111. Demodulation section 113 demodulates the reception signal using the same signal as the signal used as the modulation carrier by modulation section 105 (that is, using two signals whose phases are different by 90 degrees), and demodulates the IQ demodulated signal. obtain. An AD (analog-digital) conversion unit 114 converts the IQ demodulated signal obtained by the demodulation unit 113 into a digital IQ signal at each sampling time interval by performing AD conversion.

The analysis unit 1023 performs detection processing of the object 100 (detection of the object 100, measurement of the position of the object 100, and the like) using the signal obtained by the reception unit 1022. In the analysis unit 1023, the correlation value calculation unit 115 is configured as a pair, and for each code transmission cycle, the digital IQ signal generated by the AD conversion unit 114 and the two complementary codes generated by the code generation unit 103. Calculate the correlation value of The composition processing unit 116, the velocity calculation unit 117, and the averaging unit 118 are responsible for the process of detecting the object 100. The synthesis processing unit 116 uses the difference value (X _sub of two correlation values) obtained by the correlation value calculation unit 115 as an object detection signal (a signal for performing detection of an object and / or measurement of a position of an object). Calculate). The velocity calculation unit 117 uses the elements (X _sub (n, j) (n is an index of the code signal cycle and j is an index of the order of the elements) of the difference value obtained by the synthesis processing unit 116) Calculate 100 velocity spectra (F (f, j)). The averaging unit 118 integrates the velocity spectra calculated by the velocity calculating unit 117 to calculate an average velocity. The result processing unit 119 generates result data to be presented as a result to the user. Further, the result processing unit 119 measures the distance between the radar device 101 and the object 100 based on the object detection signal (difference value) obtained by the combination processing unit 116. Further, the result processing unit 119 performs control for presenting the generated result data to the user via the output unit 1025.

  The control unit 1024 is responsible for various controls in the radar apparatus 101. The output unit 1025 outputs (including displays) various data generated in the radar device 101.

[Specific Operation of Radar Device 101 in First Embodiment]
Subsequently, specific operations of the radar device 101 in the present embodiment will be described. First, the code generation unit 103 alternately and repeatedly generates two codes (code A and code B) constituting a complementary code at a code transmission period T _PRI . Further, the number of elements of each of the code A and the code B is n _c . The code A and code B generated by the code generation unit 103 are converted into an analog signal by the DA conversion unit 104, and are modulated by using the signal output from the local oscillator 109 by the modulation unit 105 as a modulation carrier wave. The phases of the signals input to the two modulators 105 differ by 90 degrees. This is realized by causing the phase shifter 110 to change the phase of one of the two signals output from the local oscillator 109 by 90 degrees.

  The two signals output from the modulator 105 are added by the adder 106 and output as a sum signal. The sum signal is subjected to intensity adjustment and unnecessary frequency band signal filtering in an appropriate form in the transmission RF unit 107, and is sent to the transmission antenna 108. The transmission antenna 108 outputs the signal obtained by the transmission RF unit as a radio wave. The radio wave output from the transmitting antenna 108 is irradiated to the object 100 and received by the receiving antenna 111.

Demodulation section 113, which has received the signal via reception RF section 112, demodulates the received signal using the same signal as the signal used as the modulation carrier by modulation section 105, and obtains an IQ demodulated signal. AD converter 114 converts into digital IQ signal for each sampling time interval _{t s} by AD converting the IQ demodulated signal. The correlation value calculation unit 115 calculates correlation values between the digital IQ signal generated by the AD conversion unit 114 and the two codes (code A and code B) generated by the code generation unit 103 for each code transmission cycle. calculate.

Here, with reference to FIG. 2, the temporal property of the code A will be described. Although the code A is described for the purpose of explanation, the same applies to the code B. FIG. 2 is a diagram for explaining code transmission timing. In FIG. 2, a time allocated to one element constituting the code A is represented as a bit duration t _bit (see the upper part of FIG. 2). The bit duration t _bit is a natural number multiple of the sampling time interval t _s . Since the number of elements of the code A is n _c , the time length of the code A is t _bit × n _c (see the middle part of FIG. 2). A code A having a time length of t _bit × n _c is generated / sent with an interval between code transmission cycles T _PRI (see the lower part of FIG. 2).

ここで、

である。 Subsequently, the process of the correlation value calculation unit 115 will be specifically described. An array obtained by multiplying each element of the code B among the code A and the code B generated by the code generation unit 103 by an imaginary unit i (i ² = −1) is set as a code B ′ (= iB). For the digital IQ signal generated by the AD conversion unit 114, the I signal component and the Q signal component obtained at the kth in the nth code transmission period are S ^I (n, k) and S ^Q (n, k), respectively. It is expressed as). Then, on the complex plane, if the I signal component (S ^I (n, k)) is assigned as the real axis and the Q signal component (S ^Q (n, k)) is assigned as the imaginary axis, the complex sequence S ^I (n, k) + iS ^Q (n, k) is obtained. The correlation value calculation unit 115 calculates the correlation value (correlation value X _A (n, k _d )) and correlation value X _B (n, k _d ) at element k _d between this complex sequence and each of the code A and the code B ′. ) Is calculated as follows. The real-time signals of the code A and the code B are represented as A (t) and B (t) (0 ≦ t ≦ t _bit × n _c ), respectively.

here,

It is.

The two correlation values (correlation value X _A (n, k _d ) and correlation value X _B (n, k _d )) are sent to the synthesis processing unit 116. The composition processing unit 116 calculates a difference value X _sub (n, k _d ) between the correlation value X _A (n, k _d ) and the correlation value X _B (n, k _d ).

となる。ここで、〈Ａ、Ｂ〉は、符号Ａと符号Ｂとの相関値を表す。２つの相関値の差分値Ｘ_ｓｕｂを求めると

が得られる。上記式において、右辺は符号Ａと符号Ｂそれぞれの自己相関値の和である。すなわち、差分値Ｘ_ｓｕｂは距離サイドローブが０となる値となる。 It can be explained as follows that the radar apparatus 101 can obtain an appropriate autocorrelation value by such processing. A signal obtained by demodulating the received signal is expressed as A + iB when using a complex number. Essentially, the intensity and the phase factor determined by the reflection cross section and the position of the object 100 are further multiplied. However, since they are not particularly affected, they are omitted in the present description. When the correlation value between A + iB and the codes A and B '(= iB) is obtained,

It becomes. Here, <A, B> represents the correlation value between the code A and the code B. _Find the difference value X _sub between two correlation values

Is obtained. In the above equation, the right side is the sum of the autocorrelation value of each of the code A and the code B. That is, the difference value X _sub is a value at which the distance side lobe is zero.

  As described above, in the present embodiment, since two codes A and B are simultaneously transmitted and received, it can be understood that the received signal is not affected by the movement of the object 100. Moreover, since all the above calculations are linear, they are also effective for detection of multiple objects and measurement of distances.

The combining processing unit 116 transmits the calculated difference value X _sub to the velocity calculating unit 117. The phase of the difference value X _sub changes due to a change in the distance between the radar device 101 and the object accompanying the movement of the object 100. Assuming that the object 100 is moving at constant velocity, the phase of the difference value X _sub changes at constant velocity. Therefore, a linear direction component passing through the radar device 101 of the speed of the object 100 and the object 100 can be obtained by frequency analysis by fast Fourier transform (FFT).

ｆ＝ｆ_ｐｅａｋにてＦ（ｆ、ｊ）がピーク値となるとき、そのピークは対象物１００の動きに由来しており、対象物１００の移動速度ｖ_ｔは電波の波長をλとすると、

と求まる。 When the j-th element in the n-th code transmission cycle of the difference value X _sub is represented as X _sub (n, j), the element X _sub (n + 1, j) obtains the element (n, j) and then the code It is obtained after the transmission period T _PRI . When the object 100 is moving, the element X _sub (n, j) and the element X _sub (n + 1, j) have a phase difference caused by the movement of the object 100 occurring between code transmission cycles T _PRI. . Therefore, the velocity calculation unit 117 performs FFT on X _sub (n, j) (n = 1, 2,..., N) to obtain the velocity spectrum F (f, j) as in the following equation. .

When F (f, j) becomes a peak value at f = f _peak , the peak is derived from the movement of the object 100, and the moving speed v _t of the object 100 is λ when the wavelength of the radio wave is

It is determined.

The element X _sub (n, j) of the difference value X _sub is obtained from the sum of all received signals received in the nth code transmission cycle, including the reflected signal to the object 100. By performing an FFT that is a linear calculation on element X _sub (n, j), it is possible to obtain the velocity spectrum of all received signals in all code transmission cycles for the same element.

となり、本実施形態と比較して最大検出速度は１／ｎ_ｐｅｒ倍となる。このように、本実施形態では、同一符号の送受信時間間隔を短くすることができるため、最大検出速度を高く設定できることができる。 Here, the moving speed v _t of the detected object obtained in the present embodiment is compared with the detectable moving speed in the prior art disclosed in Non-Patent Document 1. In the present embodiment, the speed is calculated from a plurality of received signals obtained for each code transmission cycle T _PRI . On the other hand, in the prior art, a plurality of sets of complementary codes are transmitted and received a plurality of times. For example, for codes A and B constituting a complementary code, assuming that codes A ′ and B ′ in which the elements of each code are reversed, are transmitted in the order of (A, B, A ′, B ′) Be done. That is, four codes are taken as one cycle. As data to be subjected to FFT, difference value elements X _sub (n, j) for the same elements obtained for each code transmission cycle are required. Therefore, assuming that the number of codes to be transmitted in one cycle is n _per (in the prior art, n _per = 4), data to be subjected to FFT is obtained for each n _per × T _PRI . Due to the nature of the FFT, the maximum detection rate v _max is

Thus, the maximum detection speed is 1 / n _per times that of the present embodiment. As described above, in the present embodiment, since the transmission / reception time interval of the same code can be shortened, the maximum detection speed can be set high.

  The velocity calculating unit 117 sends the obtained velocity spectrum F (f, j) to the averaging unit 118. The averaging unit 118 repeats the above procedure a plurality of times and integrates the velocity spectrum F (f, j) obtained similarly to improve the SN ratio and calculate the average velocity. The averaging unit 118 transmits the calculated average speed to the result processing unit 119.

  The result processing unit 119 generates result data via signal processing for presenting as a result to the user. For example, the case where the transmitting antenna 108 is configured by an analog beam forming antenna that forms a transmitting beam will be described. FIG. 3 shows the configuration of the analog beam forming antenna 301 as the transmitting antenna 108. As shown in FIG. The analog beam forming antenna 301 has an appropriate antenna gain, and transmits the transmission radio wave 302 to a part of the radio wave irradiation area. The analog beam forming antenna 301 is composed of a plurality of antenna elements, and the gain and phase of radio waves transmitted from each antenna element are adjusted by circuits such as the phase shifter 303 and the amplifier 304 in the antenna elements. The control of this circuit is performed by the control unit 1024 of the radar device 101. The output radio waves from all the antenna elements overlap, and the radio wave transmission direction is determined by the set gain and phase. That is, the control unit 1024 can set the power transmission angle. The radio wave can be scanned in the radio wave irradiation area by the control unit 1024 changing and setting the power transmission angle from time to time. In such a situation, the result processing unit 119 can generate result data in which each set radio wave transmission angle is associated with the average velocity calculated by the averaging unit 118.

  Also, for example, the case where the receiving antenna 111 is configured by a digital beam forming antenna that forms a receiving beam will be described. FIG. 4 shows the configuration of a radar apparatus 101 in which the receiving antenna 111 is a digital beam forming antenna. The digital beam forming antenna is composed of a plurality of element antennas, and a plurality of reception RF units 112, demodulation units 113, AD conversion units 114, correlation value calculation units 115, and combination processing units 116 corresponding to the respective element antennas. Is configured. The angular distribution of the incoming radio wave can be determined by analyzing the sum of the correlation values of the complementary codes obtained from each element antenna. There are various known methods of direction of arrival estimation, such as beamformer method, CAPON method, MUSIC method, and ESPRIT method.

  In the example of FIG. 4, the difference value obtained by the combination processing unit 116 is sent to the velocity calculation unit 117, and the velocity spectrum is calculated as described above. The velocity spectrum is further sent to the averaging unit 118 to calculate an average velocity. Further, the average velocity is sent to the arrival direction estimation unit 120, and the arrival direction estimation is performed. In such a situation, the result processing unit 119 sends the analysis result to the result processing unit 119, and the movement speed and distance of the object 100, the reflected signal intensity and phase map for each angle in the receiving antenna 111, etc. It becomes possible to generate as data. In addition, the result processing unit 119 is a signal related to object detection such as removal processing using characteristics of an object reflected wave that is considered to be out of detection in the usage environment, and machine learning that extracts a feature of the object based on a signal. Processing such as signal processing may be performed according to the intended application to generate result data.

  As described above, according to the present embodiment, even when an object to be detected is moving, a low-distance sidelobe object detection signal in which the influence of the Doppler shift included in the reflected signal from the object is avoided is used. You can get it. Moreover, since all calculations related to object detection are linear, they are also effective in separating and detecting a plurality of detected objects.

Second Embodiment
[Configuration of radar device]
As a second embodiment, a radar apparatus that changes the transmission code to be generated according to whether or not there is a moving object will be described. FIG. 5A shows the configuration of the radar device 102 according to the second embodiment. The same reference numerals as in FIG. 1 described in the first embodiment denote the same parts in FIG. In FIG. 5, the radar apparatus 102 has a movement determination unit 502 in addition to the configuration of FIG. 1, and has a combination processing unit 501 in place of the combination processing unit 116. The movement determination unit 502 determines whether a moving object is present in the radio wave irradiation area (whether or not an object to be detected is moving) based on the information received from the velocity calculation unit 117. The combining processing unit 501 performs combining processing on the correlation value obtained by the correlation value calculation unit 115.

[Specific Operation of Radar Device 102 in Second Embodiment]
Subsequently, the specific operation of the radar device 102 in the present embodiment will be described. The description of the same operations as the operations described in the first embodiment will be omitted.

  First, as in the first embodiment, it is assumed that the radar apparatus 102 transmits a sum signal generated from two codes forming complementary codes and receives a signal reflected by the object 100. The movement determination unit 502 receives the speed information of the detected object 100 from the speed calculation unit 117. The velocity information is a velocity spectrum that is the result of an FFT operation on the difference value of the correlation value obtained by the method described in the first embodiment, and the velocity spectrum corresponds to the amount of phase change (Doppler shift amount). . As shown in equation (7), the distance side lobe generated in the sum of the autocorrelation values increases when the code is transmitted and received as the phase change amount increases.

In the present embodiment, the movement determination unit 502 has a predetermined threshold value r _th for the ratio of the main lobe to the distance side lobe. The threshold r _th may be preset by the user. The movement determination unit 502 obtains the ratio r _s (φ _d ) of the main lobe and the distance side lobe from the velocity spectrum (phase change amount φ _d ) received from the velocity calculation unit 117, and this ratio r _s (φ _d ) It is determined whether the threshold value r _th is exceeded. When the ratio r _s (φ _d ) exceeds the threshold r _th , the movement determination unit 502 determines that the object 100 is moving (the object 100 is a moving object). The movement determination unit 502 may determine whether the object 100 is moving according to any other method.

  When it is determined by the movement determination unit 502 that the object 100 is moving, the radar device 102 continues the two codes forming the complementary code at the same time in the same manner as in the first embodiment. Send and receive. The combining processing unit 501 functions in the same manner as the combining processing unit 116 in FIG. 1, and calculates the difference value of the correlation value obtained by the correlation value calculation unit 115.

  On the other hand, when it is determined by the movement determination unit 502 that the object 100 is not moving (the object 100 is not a moving object), as shown in FIG. 5B, the control unit 1024 generates a code generation unit. 103, one of the DA converter 104 and the modulator 105 is stopped. FIG. 5B is a diagram in which the block in which the operation is stopped is grayed out when the movement determination unit 502 determines that there is no moving object, as compared with FIG. 5A. In the radar apparatus 102 configured as shown in FIG. 5B, the code generation unit 103 alternately and repeatedly generates two codes forming a complementary code. The code generated in this manner is the DA conversion unit 104. , Is converted into a transmission signal via the modulation unit 105, the addition unit 106, and the transmission RF unit 107, and is transmitted from the transmission antenna 108 in a time division manner The transmission signal is reflected by the object 100 and received by the reception antenna 111, Two correlation values are calculated through the reception RF unit 112, the demodulation unit 113, the AD conversion unit 114, and the correlation value calculation unit 115. Subsequently, the combination processing unit 501 calculates the sum of the two correlation values. The obtained signal is sent to the velocity calculation unit 117, and thereafter, the same signal processing as that of the first embodiment is performed. When it is determined that 00 has not moved, the signal output from the combining processing unit 501 may pass through the velocity calculating unit 117 and the averaging unit 118. In this case, in the result processing unit 119, The distance between the radar device 101 and the object 100 is measured based on the object detection signal.

  As described above, in the present embodiment, when there is a moving object in the vicinity, a low-range side lobe like object detection signal that avoids the influence of the Doppler shift is obtained, and when there is no moving object, An object detection signal is obtained by a method. That is, the radar apparatus 102 can appropriately switch the process for obtaining the object detection signal according to the movement of the object to be detected, and as a result, the processing load can be reduced.

  Also, from the viewpoint of radio regulation, when transmitting two codes simultaneously, it is necessary to weaken the maximum strength of the code modulation signal per one code to half of that when time-division transmitting two codes. . Therefore, when there is no moving object, it can be expected to extend the maximum detection distance by time-divisionally transmitting two codes adaptively.

Other Embodiments
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

101 102 radar apparatus, 1021 transmitting unit, 1222 receiving unit, 1023 analyzing unit, 1024 control unit, 1025 output unit

Claims (18)

First generation means for generating a first code and a second code that constitute a complementary code;
Transmission means for transmitting a transmission signal generated by combining the first code and the second code after modulation;
Receiving means for receiving the transmission signal reflected by the object as a reception signal;
Calculation means for calculating a second correlation value indicating a correlation value between a first correlation value indicating a correlation value between the received signal and the first code, and a correlation value between the received signal and a code based on the second code When,
Detection means for performing detection processing of the object based on the first correlation value and the second correlation value calculated by the calculation means;
The radar apparatus characterized by having. The radar apparatus according to claim 1, wherein the detection unit performs the process of detecting the object based on a difference value between the first correlation value and the second correlation value.
Radar equipment.   The apparatus further comprises second generation means for generating the transmission signal by modulating after modulation using a signal having a phase difference of 90 degrees with respect to the first code and the second code. The radar apparatus of claim 1 or 2. The signal processing apparatus further comprises third generation means for generating an IQ demodulated signal by performing demodulation on the received signal using the signal whose phase is different by 90 degrees,
The calculation means generates a complex sequence by assigning the I signal component of the IQ demodulated signal as a real axis and the Q signal component as an imaginary axis on a complex plane, and the correlation value between the complex sequence and the first code The radar apparatus according to claim 3, wherein the radar apparatus generates the first correlation value and calculates the correlation value between the complex sequence and the code based on the second code as the second correlation value. .   The radar apparatus according to claim 4, wherein the code based on the second code is a code obtained by multiplying each element of the second code by an imaginary unit.   The radar apparatus according to any one of claims 1 to 5, wherein the detection means detects a velocity of the object.   The said detection means is characterized by detecting the speed of the said target object from the result obtained by Fourier-transforming with respect to the difference value of said 1st correlation value and said 2nd correlation value. The radar apparatus according to 6.   The radar apparatus according to claim 6 or 7, further comprising presentation means for presenting the speed of the object detected by the detection means to a user.   When the transmission means forms a beam and transmits the transmission signal, or the reception means forms a beam and receives the reception signal, the presenting means provides information on the setting of the beam and the object. The radar apparatus according to claim 8, characterized in that the speed of "n" is associated with each other and presented to the user.   The radar apparatus according to any one of claims 1 to 5, wherein the detection means detects the position of the object.   11. The radar apparatus according to claim 10, further comprising presentation means for presenting the position of the object detected by the detection means to a user. The apparatus further comprises determination means for determining whether the object is moving or not.
When it is determined by the determination unit that the object has not moved:
The transmission means transmits, in time division, a first transmission signal and a second transmission signal, which are signals obtained by performing modulation on the first code and the second code, respectively.
The receiving means receives the first transmission signal and the second transmission signal reflected by the object as a first reception signal and a second reception signal, respectively.
The calculation means may include a third correlation value indicating a correlation value between the first received signal and the first code, and a fourth correlation value indicating the correlation value between the second received signal and the second code. Calculate the correlation value of
The radar apparatus according to any one of claims 1 to 11, wherein the detection means performs the detection process based on the third correlation value and the fourth correlation value.   The radar apparatus according to claim 12, wherein the detection means performs the detection process based on a sum of the third correlation value and the fourth correlation value.   14. The radar apparatus according to claim 12, further comprising measuring means for measuring a distance to the object based on a sum of the third correlation value and the fourth correlation value.   15. The apparatus according to claim 12, wherein said determination means determines whether or not the object is moving based on a difference value between the first correlation value and the second correlation value. The radar apparatus according to any one of the items.   The radar apparatus according to any one of claims 1 to 15, further comprising: a transmission antenna used to transmit the transmission signal; and a reception antenna used to receive the reception signal. A method of controlling a radar device
A first generation step of generating a first code and a second code that constitute a complementary code;
A transmitting step of transmitting a transmission signal generated by combining the first code and the second code after modulation;
Receiving the transmission signal reflected by the object as a reception signal;
Calculating a second correlation value indicating a correlation value between a first correlation value indicating a correlation value between the received signal and the first code and a correlation value between the received signal and a code based on the second code When,
A detection step of performing a detection process of the object based on the first correlation value and the second correlation value calculated in the calculation step;
A control method of a radar device, comprising:   A program for causing a computer to function as the radar device according to any one of claims 1 to 16.

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