JP5495611B2 - Radar equipment - Google Patents

Description

  The present invention relates to a radar apparatus that calculates a relative distance and a relative speed with respect to a target and performs target detection.

  First, a conventional target detection apparatus that removes a false speed target will be described (for example, see Patent Document 1). FIG. 27 is a configuration diagram of a conventional target detection apparatus. The signal processor 5 of the target detection apparatus disclosed in Patent Document 1 includes a distance-speed map creation means 206, a target candidate detection means 207, a distance-speed estimated value calculation means A8, and a target determination means A9. A conventional target detection apparatus calculates a target candidate, its relative distance, and relative speed using a distance-speed map creation means 206 and a target candidate detection means 207.

Next, a method for detecting the target by removing the false speed target will be specifically described. FIG. 28 is an explanatory diagram showing a method for detecting a target by removing a false speed target in a conventional target detection apparatus. The distance R1 at a certain time, as the target candidate, and the true target 114a having a velocity _{v 11,} and false speed target 115a having a velocity _{v 12} indicates the case where it is detected.

  The distance-speed estimated value calculating means A8 calculates a distance R2 corresponding to the predicted position of the true target 114a after a certain time has elapsed. The target determination unit A9 determines that the target is a target when the true target 114b is detected at a distance R2 corresponding to the predicted position of the true target 114a after a certain time has elapsed. On the other hand, if the false speed target 115a is not detected at the distance R2 corresponding to the predicted position of the true target 114a after a certain period of time, it is removed as a false speed target. In this way, the target detection performance can be improved by removing the false speed target.

Japanese Patent Laid-Open No. 10-232280

  However, the prior art has the following problems. In this conventional target detection device, if it is not detected at a predicted position after a certain time has elapsed, it is removed as a false speed target. For this reason, acceleration targets that are not detected at the predicted position after a certain time have also been removed, and the target detection performance may be degraded. FIG. 29 is an explanatory diagram showing a case where the acceleration target is removed as a false speed target in the conventional target detection apparatus, and shows a case where the acceleration target 116a is removed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a radar apparatus with improved target detection performance by removing JEM (Jet Engine Modulation) without removing an acceleration target. And

A radar apparatus according to the present invention is a radar apparatus that calculates a relative distance and a relative velocity with respect to a target and performs target detection, and a transmission unit that radiates a transmission signal in which a carrier signal is pulse-modulated at a predetermined time interval; Receiving means for receiving a transmission signal reflected and returned from the target as a received signal; distance for calculating a target relative distance and relative speed from the received signal received by the receiving means; distance for creating a speed map; The speed map creation means and the distance-speed map created by the distance-speed map creation means based on the received signal received at the first time are subjected to CFAR processing to detect target candidates at the first time, the relative distance between the target candidate, and a target candidate detection means for calculating the relative velocity of the target candidates detected in the target candidate detecting means, is a predetermined time before time than the first time The distance-speed estimated value calculating means for calculating the range of the distance-speed estimated value at two times and the target candidate detected by the target candidate detecting means based on the distance-speed map at the second time are the distance-speed estimated values. A target determination unit that determines that the target candidate detected at the first time is a target when the target candidate is within the range of the distance-speed estimated value at the second time calculated by the calculation unit; and a second time The target candidate detected by the target candidate detection means based on the distance-speed map at is not within the range of the distance-speed estimated value at the second time of the target candidate calculated by the distance-speed estimated value calculating means. And when it exists in the range of the distance-speed estimated value at the second time of JEM calculated by the distance-speed estimated value calculating means, the target candidate detected at the first time A target candidate determined as JEM, and a second target determination unit that uses the target candidate determined as JEM and the target candidate determined as a target by the target determination unit as a second target candidate. .

  The radar apparatus according to the present invention is a radar apparatus that calculates a relative distance and a relative velocity with respect to a target and performs target detection, and transmits a transmission signal in which a carrier signal is pulse-modulated at a predetermined time interval. Means, receiving means for receiving the transmission signal reflected back from the target as a received signal, and creating a distance-speed map for calculating the relative distance and relative speed of the target from the received signal received by the receiving means CFAR processing is performed on the distance-speed map created by the distance-speed map creating means and the distance-speed map creating means based on the received signal received at the first time to detect a target candidate at the first time. And a target candidate detecting means for calculating a relative distance and a relative speed with respect to the target candidate, and a target candidate detected by the target candidate detecting means after a predetermined time from the first time. The distance-speed estimated value calculating means for calculating the range of the distance-speed estimated value at the time and the target candidate detected by the target candidate detecting means based on the distance-speed map at the third time are calculated as the distance-speed estimated value. If the target candidate calculated by the means is within the range of the distance-speed estimated value at the third time, target determining means for determining the target candidate detected at the third time as the target, and at the third time The target candidate detected by the target candidate detecting means based on the distance-speed map does not exist within the range of the distance-speed estimated value at the third time of the target candidate calculated by the distance-speed estimated value calculating means, And when it exists in the range of the distance-speed estimated value in the 3rd time of JEM calculated by the distance-speed estimated value calculation means, the target candidate detected in the 3rd time is selected. A target candidate determined as EM, and a target candidate determined as JEM, and a second target determination unit that uses the remaining target candidates excluding the target candidate determined as a target by the target determination unit as a second target candidate. .

  According to the radar apparatus of the present invention, the acceleration target is removed by including the second target determination unit that identifies the target candidate that has not been determined as the target by the target determination unit, as JEM and other targets. Without removing JEM (Jet Engine Modulation), a radar apparatus with improved target detection performance can be obtained.

It is a block diagram of the radar apparatus in Embodiment 1 of this invention. It is explanatory drawing which showed the processing content of the distance-speed map preparation means in Embodiment 1 of this invention. It is an illustration figure of the distance-speed map created by the distance-speed map preparation means of Embodiment 1 of this invention. It is explanatory drawing of the target detection process by the target candidate detection means of Embodiment 1 of this invention. In the target candidate detection means of Embodiment 1 of this invention, it is explanatory drawing of the processing content when the cell exceeding a CFAR threshold value gathers as a result of CFAR processing. FIG. 7 is an explanatory diagram showing distance-speed estimated values at time t−Δt when two target candidates are detected at time t and distance R (t) by the target candidate detecting unit according to the first embodiment of the present invention. is there. It is explanatory drawing of the target determination process by the target determination means of Embodiment 1 of this invention. It is a figure for demonstrating the target detection of the acceleration target in Embodiment 1 of this invention. It is explanatory drawing of the 2nd target determination method in Embodiment 1 of this invention. It is explanatory drawing regarding the determination method of JEM by the 2nd target determination means of Embodiment 1 of this invention. It is explanatory drawing of the 2nd target determination method in Embodiment 1 of this invention. It is a block diagram of the radar apparatus in Embodiment 2 of this invention. It is explanatory drawing about the relative speed calculation method of the target candidate in consideration of the number of speed turns in Embodiment 2 of this invention. It is a comparison explanatory drawing about the relative speed calculation method of the target candidate when not considering the number of speed turns in Embodiment 2 of this invention, and when it considers. It is a block diagram of the radar apparatus in Embodiment 3 of this invention. It is explanatory drawing which showed the distance-speed estimated value in the time t + (DELTA) t when the target candidate detection means of Embodiment 3 of this invention detects two target candidates in the distance R (t) at the time t. It is explanatory drawing of the target determination process by the target determination means of Embodiment 3 of this invention. It is a block diagram of the radar apparatus in Embodiment 4 of this invention. It is explanatory drawing which showed the frequency of the transmission signal of a speed measurement phase and the ranging phase in Embodiment 4 of this invention, and a received signal. It is explanatory drawing which showed the processing flow of the target candidate detection in Embodiment 4 of this invention. It is explanatory drawing which shows the case where 1 target is detected in each phase in Embodiment 4 of this invention. It is explanatory drawing of the target detection process in the frequency domain by the target candidate detection means 207B of Embodiment 4 of this invention. It is explanatory drawing which shows the condition in case the 2 target and JEM exist in each phase in the time t in the Embodiment 4 of this invention, and time t- (DELTA) t. It is explanatory drawing which shows the case where 2 targets and JEM are detected in each phase in the time t in Embodiment 4 of this invention. It is a figure which shows the ranging result calculated from the combination when two targets and JEM are detected in each phase in the time t in Embodiment 4 of this invention. In the fourth embodiment of the present invention, the distance measurement results of fv and _{T1 in the} speed measurement phase and the distance measurement 1 phase, and the distance measurement results of fv _{and T1 in the} speed measurement phase and the distance measurement 2 phase It is explanatory drawing for calculating the relative distance of a target candidate from a difference. It is a block diagram of the conventional target detection apparatus. It is explanatory drawing which showed the method of removing a false speed target and detecting a target in the conventional target detection apparatus. It is explanatory drawing which showed the case where the acceleration target is removed as a false speed target in the conventional target detection apparatus.

  A preferred embodiment of a radar apparatus according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a radar apparatus according to Embodiment 1 of the present invention. The radar apparatus in FIG. 1 includes an antenna 1, a transmitter 2, a transmission / reception switch 3, a receiver 4, a signal processor 205A, and a display 20.

  Further, the signal processor 205A includes a distance-speed map creating unit 206, a target candidate detecting unit 207, a distance-speed estimated value calculating unit 208, a target determining unit 209, and a second target determining unit 210. Hereinafter, an operation until a reception video signal is generated will be described.

  The transmitter 2 performs pulse modulation on the carrier signal at a pulse repetition interval (hereinafter referred to as PRI) to generate a transmission RF signal, and outputs the transmission RF signal to the transmission / reception switch 3. The transmission / reception switch 3 outputs the transmission RF signal input from the transmitter 2 to the antenna 1. As a result, the transmission RF signal is radiated from the antenna 1 into the air.

  The transmission RF signal radiated into the air is reflected by the target and enters the antenna 1 as a reflected RF signal. Therefore, the antenna 1 receives the incident reflected RF signal and outputs it to the transmission / reception switch 3 as a received RF signal. The transmission / reception switch 3 outputs the reception RF signal input from the antenna 1 to the receiver 4. The receiver 4 amplifies and phase-detects the received RF signal input from the transmission / reception switch 3, converts it to a received video signal, and outputs it to the signal processor 205A.

  The signal processor 205A is composed of a computer having a CPU, a RAM, a ROM, and an interface circuit, and arithmetic processing is performed by the CPU in accordance with a program stored in the ROM. The processing result of the signal processor 205A is recorded in the computer.

Hereinafter, processing contents of each unit will be described.
FIG. 2 is an explanatory diagram showing the processing contents of the distance-speed map creation means 206 according to Embodiment 1 of the present invention. The distance-velocity map creating means 206 performs chirp pulse compression in the distance direction in order to create a distance-velocity map. The received video signal V (s, n, m) input to the distance-speed map creating means 206 is expressed by the following equation (1).

Here, each code | symbol in the said Formula (1) means the following.
A _tgt : Amplitude of the received video signal f ₀ : Transmission center frequency of the transmission RF signal T ₀ : Transmission pulse width of the transmission RF signal R ₀ (s): Initial relative distance from the target when creating the distance-speed map v _tgt : Relative speed with target T _pri : Pulse repetition period s: Distance-speed map number S: Number of distance-speed map creation n: Pulse number N: Number of pulses m: 1 Sampling number in PRI M: Number of sampling points in PRI

  Further, chirp is assigned 1 when the transmission RF signal is up-chirp modulated, and is assigned -1 when it is down-chirp modulated.

Further, the initial relative distance R ₀ (s) to the target at the time of creating the distance-speed map is expressed by the following equation (2).

  The distance-velocity map creation means 206 performs correlation calculation between the received video signal V (s, n, m) and the reference signal, and performs chirp pulse compression.

The reference signal Ex (m _τ ) used by the distance-velocity map creating unit 206 has a complex conjugate relationship with the modulation component of the transmission RF signal, and is represented by the following expression (3). Further, the number of sampling points _Mτ of the reference signal is expressed by the following equation (4).
Here, the symbols in the following formulas (3) and (4) mean the following.
A ′: Reference signal amplitude m _τ : Reference signal sampling number Samp_f: Sampling frequency for the received video signal

The distance-velocity map creating means 206 converts the received video signal V (s, n, m) and the reference signal Ex (m _τ ) into fast Fourier transforms (FFT: Fast Fourier) according to the following equations (5) and (6). (Transform), and then multiply according to the following equation (7). Here, l represents the range bin number, and L ′ represents the number of FFT points in the range direction. However, when L ′> M, 0 is substituted for V (s, n, m), and when L ′> M _τ , 0 is substituted for Ex (m _τ ).

  Further, when the signal after chirp pulse compression is sampled with higher accuracy than the sampling interval before chirp pulse compression, the distance-velocity map creating means 206 sets 0 by the following equation (8). Here, L is the number of inverse fast Fourier transforms (IFFT) in the range direction, and is expressed by the following equation (9). However, q is an integer greater than or equal to 0. When q = 0, the sampling interval is the same as the sampling interval before chirp pulse compression.

The distance-velocity map creating means 206 performs inverse fast Fourier transform (IFFT) on the multiplication result according to the following equation (10), and obtains the result of correlation calculation, that is, the signal R _{V. Ex} (s, n, l) is output.

Further, the distance-velocity map creating means 206 performs fast Fourier transform processing on the signal R _{V · Ex} (s, n, l) after the chirp pulse compression in the pulse direction according to the following equation (11), for each range bin. , That is, a frequency spectrum, and a distance-speed map FR (s, k _h , l) is created. Here, _{k h} is the frequency bin number, H is representative of a pulse direction FFT points. However, when H> N, R _{V · Ex} (s, n, l) is zero-padded. The relative velocity vel corresponding to a frequency bin number _{(k h)} is expressed by the following equation (12).

  As described above, the distance-speed map creating unit 206 creates a distance-speed map by performing chirp pulse compression in the range direction and fast Fourier transform in the pulse direction. FIG. 3 is an exemplary diagram of a distance-speed map created by the distance-speed map creating unit 206 according to the first embodiment of the present invention. The created distance-speed map is output to the target candidate detection means 207.

  Next, processing contents of target detection by CFAR (Constant False Alarm Rate) processing performed in the target candidate detection unit 207 will be described. FIG. 4 is an explanatory diagram of the target detection process performed by the target candidate detection unit 207 according to the first embodiment of the present invention. More specifically, FIG. 4 is a diagram for explaining a target cell, a guard cell, and a sample cell related to the CFAR process.

The target candidate detection means 207 performs CFAR processing on the distance-speed map obtained from the distance-speed map creation means 206 by the following equation (13) to detect target candidates. Here, FR _CFAR (s, k _h , l) represents a target candidate detection result by the CFAR process, and 0 is set as the target candidate.

Further, CFAR threshold _{CFAR_th (s, k h, l} ) is calculated by the following equation (14). Here, CFAR_cor represents a CFAR coefficient, Samp_cell (s, k _h , l) represents a sample cell, and ave (Z (p)) represents an average value of the array Z (p). However, when cells exceeding the CFAR threshold value CFAR_th (s, k _h , l) are collected, a cell indicating the maximum amplitude value in the set is detected as a target candidate. FIG. 5 is an explanatory diagram of processing contents when cells exceeding the CFAR threshold are gathered as a result of the CFAR processing in the target candidate detection unit 207 according to the first embodiment of the present invention.

Next, the distance-speed estimated value calculating unit 208 calculates the distance and speed estimated values of the past target candidates from the target candidates obtained from the target candidate detecting unit 207. FIG. 6 shows distance-speed estimated values at time t−Δt when two target candidates are detected at time t and distance R (t) by the target candidate detecting unit 207 according to the first embodiment of the present invention. It is explanatory drawing shown. More specifically, the distance-speed estimated value at time t-Δt when the target is detected as target candidate 1 and JEM is detected as target candidate 2 is shown. Here, it is assumed that the speed of the target candidate 1 at time t is v ₁ and the speed of the target candidate 2 is v ₂ .

  The distance-speed estimated value calculating means 208 calculates the distance-speed estimated value of the target candidate at time t-Δt by the following equations (15), (16).

Here, the respective symbols in FIG. 6 and the above equations (15) and (16) mean the following.
R ₁ , ₁ and R _1,2 : Range of distance estimate of target candidate 1 at time t−Δt R _{2, 1} and R _{2, 2} : Range of distance estimate of target candidate 2 at time t−Δt W _R : Distance estimation width at time t-Δt v _1,1, and v _1,2 : Range of speed estimation value of target candidate 1 at time t-Δt v _2,1, and v _2,2 : Target candidate at time t-Δt 2 Speed estimation value range W _v : Speed estimation width at time t−Δt

  The target detection performance can be improved by giving an estimation range to the past distance-speed estimation value and considering the estimation error between the distance and the speed.

  Next, processing contents at time t−Δt will be described. FIG. 7 is an explanatory diagram of target determination processing by the target determination unit 209 according to Embodiment 1 of the present invention. More specifically, FIG. 7 shows a distance-speed map at time t-Δt, and the target candidate detection unit 207 uses the distance-speed map at time t-Δt to detect the distance R (t−Δt ) Shows a case where target candidate 1 and target candidate 2 are detected.

  The target determination unit 209 uses the distance-speed map at the time t-Δt to detect the target candidate within the range of the distance-speed estimated value of the target candidate at the time t-Δt obtained from the distance-speed estimated value calculation unit 208. If the means 207 has detected a target candidate, it is determined as a target.

  The conventional target detection apparatus disclosed in Patent Document 1 determines that the range of the distance-speed estimated value is within the range, and removes the range outside the range as JEM, that is, a false speed target. However, in the case of the acceleration target, the conventional target detection device has a problem that the target detection performance deteriorates because the acceleration target is removed as a false speed target. Therefore, the target determination unit 209 performs only target determination for improving target detection performance, and the second target determination unit 210 determines JEM and acceleration target.

  FIG. 8 is a diagram for explaining target detection of an acceleration target in the first embodiment of the present invention. FIG. 9 is a flowchart of the second target determination method according to Embodiment 1 of the present invention. In the first embodiment, determination of JEM and acceleration target is performed by the second target determination unit 210.

  The second target determination unit 210 performs the second target determination on the target candidates that have not been determined as target by the target determination unit 209. More specifically, as shown in FIG. 9, the second target determination unit 210 performs three types of determination: JEM, acceleration target, and second target candidate. Here, the second target candidate represents a target candidate that has not been determined as any of the target, JEM, and acceleration target among the target candidates.

  FIG. 10 is an explanatory diagram relating to a JEM determination method performed by the second target determination unit 210 according to Embodiment 1 of the present invention. The second target determination unit 210 determines the range of the distance estimation value of the target candidate 1 determined as the target obtained from the distance-speed estimation value calculation unit 208 and the range of the distance estimation value of the JEM. 2 is set as the range of the estimated speed value. The second target determination unit 210 detects a target candidate within the range of the JEM distance-speed estimated value at time t-Δt, and sets the target candidate as the distance-speed estimated value of target candidate 2 at time t-Δt. Is detected as JEM.

  As described above, even when JEM is continuously detected as a target candidate, using the JEM distance-speed estimated value and the target candidate 2 distance-speed estimated value at time t-Δt, the JEM may be mistaken as a target. It can be expected that the target detection performance will be improved.

Next, a method of determining an acceleration target as a second target candidate without removing the acceleration target as JEM will be described. FIG. 11 is an explanatory diagram of a second target determination method according to Embodiment 1 of the present invention. More specifically, at the time t−Δt when the target candidate is detected as the target candidate 3 having the speed v ₃ at the distance R ₃ (t−Δt) at the time t−Δt by the target candidate detection unit 207. A distance-speed map is shown.

When the target candidate 2 detected at the distance R (t) at the time t and the target candidate 3 detected at the distance R ₃ (t−Δt) at the time t−Δt are the same target having the acceleration a, The relationship of the following formula (17) is established. The second target determination unit 210 calculates the acceleration estimated value a _est by the following equation (18).

The second target determination unit 210 does not detect the target candidate in the JEM distance-speed estimated value at time t-Δt, and detects the target candidate in the distance-speed estimated value of target candidate 2 at time t-Δt. If not, a target candidate that satisfies the following equation (19) is determined as an acceleration target, and a target candidate that does not satisfy the following equation (19) is determined as a second target candidate. Here, a ₁ and a ₂ represent the range of acceleration estimated values.

  Thereafter, the processing of the distance-speed map creating means 206 and the target candidate detecting means 207 is continued. When the target candidate detecting unit 207 detects the target candidate, the comparison with the second target candidate at time t−Δt is performed by comparing the distance-speed estimated value calculating unit 208, the target determining unit 209, and the second target determining unit. By using the means 210, the target detection performance is improved.

  When it is determined that the target is a target or an acceleration target from the target candidates, the display unit 20 displays the relative distance and the relative speed at time t on the screen as target information.

  As described above, according to the first embodiment, JEM, acceleration target, target, JEM, and second target determination unit are used for target candidates that have not been determined as target by the target determination unit. It has a configuration for identifying three types of target candidates that are not determined as any of the acceleration targets. As a result, the acceleration target is not erroneously detected as JEM and removed, and a radar apparatus with improved target detection performance can be obtained.

  Further, when a target candidate is detected, a configuration is provided in which the target candidate is compared with the target candidate whose time is back. For this reason, the presence or absence of the target can be determined before the target approaches the radar apparatus, and the target can be promptly dealt with, thereby further improving the target detection performance of the radar apparatus.

Embodiment 2. FIG.
FIG. 12 is a configuration diagram of the radar apparatus according to Embodiment 2 of the present invention. 12 includes an antenna 1, a transmitter 2, a transmission / reception switch 3, a receiver 4, a signal processor 205B, and a display 20.

  In addition to the distance-speed map creation unit 206, the target candidate detection unit 207, the distance-speed estimated value calculation unit 208, the target determination unit 209, and the second target determination unit 210, the signal processor 205B further includes a speed. Folding number calculating means 211 is provided.

  That is, the configuration of FIG. 12 in the second embodiment is different from the configuration of FIG. 1 in the first embodiment in the configuration of the signal processors (205A, 205B). More specifically, the signal processor 205B according to the second embodiment is further provided with a speed turn number calculating means 211 between the target candidate detecting means 207 and the distance-speed estimated value calculating means 208. Is different.

  In the target detection device in the previous Patent Document 1, the speed information calculation method has not been clarified, but in a general radar device, as in the first embodiment, by performing FFT in the pulse direction, Calculate the relative speed with the target. However, in such a calculation method, when the target speed is turned back, there is a possibility that the distance-speed estimation value is incorrect and the target detection performance is deteriorated. Therefore, the radar apparatus according to the second embodiment calculates the number of speed wraps for the purpose of improving the target detection performance, and makes it possible to calculate an accurate relative speed.

FIG. 13 is an explanatory diagram of a target candidate relative speed calculation method in consideration of the number of speed turns according to the second embodiment of the present invention. The speed folding number calculating means 211 calculates the speed estimated value v _est by the following equation (20). Here, R (t) represents the relative distance of the target candidate at time t, and R (t−Δt) represents the relative distance of the target candidate at time t−Δt.

The speed turn number calculating means 211 calculates a target candidate relative speed candidate by the following equation (21). Further, the folding speed v _band is represented by the following expression (22).

Here, each code | symbol in the above Formula (21) means the following.
v _{1, est} (i): target candidate 1 relative speed candidate v _{2, est} (i): target candidate 2 relative speed candidate i: speed folding number v _band : folding speed v ′ ₁ : folded target candidate 1 Relative speed v ′ ₂ : relative speed of target candidate 2 that has been turned back I: maximum number of speed turns

The speed turn number calculating means 211 calculates the difference between the speed estimated value v _est and the target candidate relative speed candidate by the following equation (23). Further, the speed return number calculation unit 211 calculates the speed return number of the target candidate by the following equation (24).

Here, each code | symbol in the said Formula (23) and (24) means the following.
Δv _{1, est} (i): difference between the speed estimated value v _est and the target candidate 1 relative speed candidate v _{1, est} (i) Δv _{2, est} (i): the speed estimated value v _est and the target candidate 2 relative speed Difference between candidates v _{2 and est} (i) abs (X): Maximum value of variable X i _{1, est} : Number of speed wraps of target candidate 1 i _{2 est} : Number of speed wraps of target candidate 2 min_i (Y (i) ): I indicating the minimum value of the array Y (i)

  Furthermore, the speed return number calculating unit 211 calculates the relative speed of the target candidate considering the speed return by the following equation (25).

Here, each symbol in the above formula (25) means the following.
v ″ _{1, est} : Relative speed of target candidate 1 considering speed folding v ″ _{2, est} : Relative speed of target candidate 2 considering speed folding

  FIG. 14 is a comparative explanatory diagram for the method for calculating the relative speed of the target candidate when the number of speed turns in the second embodiment of the present invention is not considered and when it is considered. As shown in FIG. 14A, when the distance-speed estimated value is calculated using the relative speed of the target candidate whose speed is turned back, the accuracy of the distance-speed estimated value deteriorates and the target detection performance deteriorates.

  On the other hand, as shown in FIG. 14B, the speed return number calculation unit 211 accurately calculates the relative speed of the target candidate considering the speed return number and the speed return. As a result, the accuracy of the distance-speed estimated value is improved, and the target detection performance can be improved.

  As described above, according to the second embodiment, the configuration is further provided with the speed return number calculation means that can consider the speed return number and the speed return. As a result, even when the speed is turned back, it is possible to calculate the relative speed of the target candidate with high accuracy, and it is possible to obtain a radar apparatus that improves the target relative speed calculation accuracy and the target detection performance.

  Furthermore, even when the speed is turned back, the JEM can be determined with high accuracy and the acceleration target can be set as the second target candidate in the same manner as in the first embodiment, thereby improving the target detection performance. The illustrated radar apparatus can be obtained.

Embodiment 3 FIG.
FIG. 15 is a configuration diagram of the radar apparatus according to Embodiment 3 of the present invention. The radar apparatus in FIG. 15 includes an antenna 1, a transmitter 2, a transmission / reception switch 3, a receiver 4, a signal processor 205C, and a display 20.

  Further, the signal processor 205C includes a distance-speed map creating unit 206, a target candidate detecting unit 207, a distance-speed estimated value calculating unit 208B, a target determining unit 209B, and a second target determining unit 210B.

  That is, the configuration of FIG. 15 in the third embodiment is different from the configuration of FIG. 1 in the first embodiment in the configuration of the signal processors (205A, 205C). More specifically, the signal processor 205C in the second embodiment is the distance-speed estimated value calculation means 208, the target determination means 209, and the second target determination of the signal processor 205A in the first embodiment. Instead of the means 210, a difference is that a distance-speed estimated value calculation means 208B, a target determination means 209B, and a second target determination means 210B are provided.

  When the target, JEM, acceleration target, and second target candidate are determined, the previous embodiment 1 compares with the past target candidate, whereas the present embodiment 3 shows that after a certain time has elapsed. Comparison with target candidates. Therefore, distance-speed estimated value calculation means 208B and target determination means 209B will be described as a processing example to be compared with target candidates after a certain period of time, and description of second target determination means 210B performed in the same way will be omitted. To do.

The distance-speed estimated value calculating means 208B calculates the distance and speed estimated values of the target candidate after a certain time from the target candidates obtained from the target candidate detecting means 207. FIG. 16 shows the distance-speed estimated value at time t + Δt when two target candidates are detected at the distance R (t) at time t by the target candidate detecting unit 207 according to the third embodiment of the present invention. It is explanatory drawing. Further, the speed of target candidate 1 at time t is v ₁ , and the speed of target candidate 2 is v ₂ .

  The distance-speed estimated value calculation means 208B calculates the distance-speed estimated value of the target candidate at time t + Δt by the following equations (26), (27).

Here, each code | symbol in the said Formula (26) and (27) means the following.
R ″ ₁ , ₁ and R ″ _1,2 : Range of distance estimated value of target candidate 1 at time t + Δt R ″ ₂ , ₁ and R ″ _{2, 2} : Range of distance estimated value of target candidate 2 at time t + Δt W ″ _R : Distance estimation width at time t + Δt v ″ ₁ , ₁ and v ″ _{1, 2} : Range of speed estimation value of target candidate 1 at time t + Δt v ″ _{2, 1} and v ″ _{2, 2} : Target candidate 2 at time t + Δt Speed estimation value range W ″ _v : Speed estimation width at time t + Δt

  The target detection performance can be improved by giving an estimation range to the distance-speed estimation value after a certain period of time and considering the estimation error of the distance and speed.

  Next, processing contents at time t + Δt will be described. FIG. 17 is an explanatory diagram of the target determination process performed by the target determination unit 209B according to Embodiment 3 of the present invention. More specifically, FIG. 17 shows a distance-velocity map at time t + Δt. Using the distance-velocity map at time t + Δt, the target candidate detecting unit 207 determines that the target candidate 1 and the target candidate 1 at distance R (t + Δt). The case where the target candidate 2 is detected is shown.

  When the target candidate is detected within the range of the distance-speed estimated value of the target candidate at time t + Δt obtained from the distance-speed estimated value calculating means 208B, the target determining means 209B determines as a target.

  As described above, according to the third embodiment, the target determination unit that determines the target using the target candidate at time t and the target candidate at time t + Δt is provided. Further, the target candidate that was not determined as the target by the target determination means was not determined as JEM, acceleration target, target, JEM, or acceleration target by using the second target determination means. It has a configuration for identifying three types of target candidates. As a result, the acceleration target is not erroneously detected as JEM and removed, and a radar apparatus with improved target detection performance can be obtained.

Embodiment 4 FIG.
FIG. 18 is a configuration diagram of a radar apparatus according to Embodiment 4 of the present invention. The radar apparatus in FIG. 18 includes an antenna 1, a transmitter 2B, a transmission / reception switch 3, a receiver 4B, a signal processor 205D, and a display 20.

  The signal processor 205D includes a frequency domain conversion unit 212, a target candidate detection unit 207B, a second target candidate detection unit 213, a distance-speed estimated value calculation unit 208, a target determination unit 209, and a second target determination unit. 210 is provided.

  That is, in the configuration of FIG. 18 in the fourth embodiment, the transmitter (2, 2B), the receiver (4, 4B), the signal processor (205A) are compared with the configuration of FIG. 1 in the first embodiment. , 205D) is different.

  More specifically, the transmitter 2B and the receiver 4B according to the fourth embodiment handle the transmission signal and the reception signal of a carrier signal having a constant frequency in the speed measurement phase, and the distance measurement 1 phase and the distance measurement 2 The difference is that it handles transmission signals and reception signals that are frequency-modulated in different phases. Further, the signal processor 205D includes a frequency domain conversion unit 212 instead of the distance-speed map creation unit 206, a target candidate detection unit 207B and a second target candidate detection unit 213 instead of the target candidate detection unit 207. The point is different.

  FIG. 19 is an explanatory diagram showing the frequencies of the transmission signal and the reception signal in the speed measurement phase and the distance measurement phase according to Embodiment 4 of the present invention. As shown in FIG. 19, according to the fourth embodiment, in the speed measurement phase, a relative speed with respect to the target or JEM is calculated by transmitting and receiving a carrier signal having a constant frequency, and a distance measurement 1 phase and a distance measurement 2 In the phase, the relative distance from the target or JEM is calculated by transmitting and receiving a frequency-modulated carrier signal.

Here, f _{0 and H} are transmission minimum frequencies in the fourth embodiment, B _{0 and R} are frequency modulation bandwidths in the fourth embodiment, and T _obs are observations of each phase in the fourth embodiment. time, f _v is the frequency observed in the measured speed phase, f _R1, the frequency observed in the range finding one phase, f _R2 respectively represent the frequency observed in the distance measuring two-phase. Further, FIG. 19 shows a case where the observation time of each phase is the same, but this observation time may be different. FIG. 19 shows a case where the frequency modulation bandwidths of the ranging 1 phase and ranging 2 phase are the same, but different frequency modulations may be performed.

  FIG. 20 is an explanatory diagram showing a processing flow for target candidate detection in the fourth embodiment of the present invention. Hereinafter, the target candidate detection process flow will be described in detail with reference to FIG.

First, the operation of the transmitter 2B in each phase will be described.
In the speed measurement phase, the transmitter 2B generates a transmission RF signal Tx _v (t) obtained by pulse-modulating a carrier signal having a constant frequency expressed by the following equation (28) with PRI, and outputs it to the transmission / reception switch 3. .

Here, each symbol in the above formula (28) means the following.
f _{0, H} : Transmission minimum frequency A _{Tx, v} : Amplitude of transmission signal in speed measurement phase T _{pri, v} : Pulse repetition period of speed measurement phase n _v : Pulse number of speed measurement phase N _v : Pulse in speed measurement phase Number T _{0, v} : Pulse width of speed measurement phase

The transmission / reception switch 3 outputs the transmission RF signal Tx _v (t) input from the transmitter 2B to the antenna 1. As a result, the transmission RF signal Tx _v (t) is radiated from the antenna 1 into the air. Thus, since there is a speed measurement phase for speed measurement, it is possible to calculate the relative speed with high accuracy without speed ambiguity.

Next, in the case of the ranging 1 phase, the transmitter 2B generates a transmission RF signal Tx _R1 (t) by pulse-modulating the frequency-modulated carrier signal represented by the following equation (29) with the PRI, and transmits and receives Output to the switch 3 and the receiver 4B.

  Here, each code | symbol in said Formula (29) means the following.

A _{Tx, R} : Amplitude of transmission signal of ranging 1 phase and ranging 2 phase T _{pri, R} : Pulse repetition period of ranging 1 phase and ranging 2 phase n _R : of ranging 1 phase and ranging 2 phase Pulse number N _R : Number of pulses in ranging 1 phase and ranging 2 phase T _{0, R} : Pulse width of ranging 1 phase and ranging 2 phase

The transmission / reception switch 3 outputs the transmission RF signal Tx _R1 (t) input from the transmitter 2B to the antenna 1. As a result, the transmission RF signal Tx _R1 (t) is radiated from the antenna 1 into the air.

Further, in the case of the ranging 2 phase, the transmitter 2B performs pulse modulation on the carrier signal, which has been frequency-modulated different from the ranging 1 phase represented by the following equation (30), with the transmission RF signal Tx _R2 (t). Is output to the transmission / reception switch 3 and the receiver 4B.

Here, frequency modulation in the ranging 1 phase and ranging 2 phase uses the same chirp change rate and different signs, but the same code and different chirp change rates may be used. The transmission / reception switch 3 outputs the transmission RF signal Tx _R2 (t) input from the transmitter 2B to the antenna 1. As a result, the transmission RF signal Tx _R1 (t) is radiated from the antenna 1 into the air.

  The transmission RF signal radiated into the air in each phase (speed measurement phase, distance measurement 1 phase, and distance measurement 2 phase) is reflected by the target and enters the antenna 1 as a reflected RF signal. Therefore, the antenna 1 receives the incident reflected RF signal and outputs it to the transmission / reception switch 3 as a received RF signal.

  The transmission / reception switch 3 outputs the reception RF signal input from the antenna 1 to the receiver 4B. The receiver 4B amplifies and phase-detects the received RF signal input from the transmission / reception switch 3, and then converts the received RF signal into a received video signal in the case of the speed measurement phase, and performs ranging 1 phase and ranging 2 phase. In this case, it is converted into a received beat signal and output to the signal processor 205D.

Next, the operation of the receiver 4B in each phase will be described. However, the case where there is one target will be described.
In the speed measurement phase, the reflected RF signal Rx _v (t) reflected by the target is expressed by the following equation (31). Here, R ₀ represents an initial relative distance from the target, and v represents a relative speed with respect to the target.

The receiver 4B passes the reflected RF signal Rx _v (t) input from the transmission / reception switch 3 through a narrowband filter, and then receives the received video signal V _v (n _v ) represented by the following equation (32). Is output to the signal processor 205D.

In the case of the ranging 1 phase, the reflected RF signal Rx _R1 (t) reflected by the target is expressed by the following equation (33).

The receiver 4B down-converts the reflected RF signal Rx _R1 (t) input from the transmission / reception switch 3 using the transmission RF signal Tx _R1 (t) input from the transmitter 2B, and then: The received beat signal V _R1 (n _R1 ) represented by (34) is output to the signal processor 205D.

In the case of the ranging 2 phase, the reflected RF signal Rx _R2 (t) reflected by the target is expressed by the following equation (35).

The receiver 4B down-converts the reflected RF signal Rx _R2 (t) input from the transmission / reception switch 3 using the transmission RF signal Tx _R1 (t) input from the transmitter 2B, and then: The received beat signal V _R2 (n _R2 ) represented by 36) is output to the signal processor 205D.

The frequency domain converting means 212 converts the time-domain received video signal and received beat signal input from the receiver 4B into the frequency domain.
In the case of the speed measurement phase, the frequency domain transforming means 212 performs fast Fourier transform represented by the following equation (37) on the received video signal V _v (n _v1 ) in the time domain, and receives the signal converted into the frequency domain. The video signal F _Vv (k _v ) is output to the target candidate detection means 207B. Here, L ′ _v represents the number of FFT points. However, 0 is substituted when L ′ _v > N _v .

Further, in the case of the ranging 1 phase, the frequency domain converting means 212 performs fast Fourier transform expressed by the following equation (38) on the received beat signal V _R1 (n _R ) in the time domain and converts it into the frequency domain. The received beat signal F _VR1 (k _R ) is output to the target candidate detecting means 207B. Here, L ′ _R represents the number of FFT points. However, when L ′ _R > N _R , 0 is substituted.

Further, in the case of the ranging 2 phase, the frequency domain transforming means 212 performs fast Fourier transform represented by the following equation (39) on the received beat signal V _R2 (n _R ) in the time domain, and transforms it into the frequency domain. The received beat signal F _VR2 (k _R ) is output to the target candidate detection means 207B.

  Next, processing contents of target detection by CFAR processing performed in the target candidate detection unit 207B will be described. First, a case where one target is detected in each phase will be described. FIG. 21 is an explanatory diagram showing a case where one target is detected in each phase in the fourth embodiment of the present invention. FIG. 22 is an explanatory diagram of target detection processing in the frequency domain by the target candidate detection unit 207B according to the fourth embodiment of the present invention. More specifically, FIG. 22 is a diagram for explaining a cell of interest, a guard cell, and a sample cell related to CFAR processing.

  Further, here, in order to explain the method of calculating the relative speed and the relative distance from the target by the target candidate detecting means 207B, a case where one target is detected in each phase as shown in FIG. 21 will be described.

First, in the speed measurement phase, the target candidate detecting unit 207B performs CFAR processing on the received video signal F _Vv (k _v ) in the frequency domain obtained from the frequency domain converting unit 212 by the following equation (40). , Detect target candidates.

Here, F _{Vv, CFAR} (k _v ) represents a speed measurement phase target candidate detection result by CFAR processing of the received video signal in the frequency domain of the speed measurement phase, and 0 is set as the target candidate for the speed measurement phase.

The CFAR threshold value CFAR_th _v (k _v ) is calculated by the following equation (41). Here, CFAR_cor _v is the CFAR coefficient of the speed measurement phase, Samp_cell (k _v ) is the sample cell, and ave (Z (p)) is the average value of the array Z (p).

In the speed measurement phase, the target candidate detection unit 207B calculates the relative speeds v _{v and T} of the detected target candidate using the following equation (42).

Next, in the case of the ranging 1 phase, the target candidate detecting unit 207B performs the CFAR process on the frequency domain received beat signal F _VR1 (k _R ) obtained from the frequency domain converting unit 212 by the following equation (43). The target candidate of the ranging 1 phase is detected.

Here, F _{VR1 and CFAR} (k _R ) represent target candidate detection results by CFAR processing of received beat signals in the frequency domain of ranging 1 phase, and 0 is set as the ranging candidate candidate for ranging 1 phase.

The CFAR threshold value CFAR_th _R1 (k _R ) is calculated by the following equation (44). Here, CFAR_cor _R1 represents a CFAR coefficient of ranging 1 phase.

In the case of the ranging 1 phase, the target candidate detection unit 207B calculates the relative speeds R ′ _{0, R1, and T} of the detected target candidates by the following expression (45). Further, when using the frequencies f_R ′ _{0, R1, and T} corresponding to the relative speeds R ′ _{0, R1, and T} of the target candidates, the calculation is performed by the following equation (46).

Also in the distance measurement 2 phase, as in the distance measurement 1 phase, the target candidate detection unit 207B applies the above equation (43) to the received beat signal F _VR2 (k _R ) in the frequency domain obtained from the frequency domain conversion unit 212. ) To carry out CFAR processing and detect target candidates for ranging 2 phase.

In the ranging 2 phase, the target candidate detecting unit 207B calculates the relative speeds R′0 _{, R2, and T} of the detected target candidates by the following equation (47). Further, when using the frequencies f_R ′ _{0, R2, and T} corresponding to the target candidate relative speeds R ′ _{0, R2, and T} , the calculation is performed by the following equation (48).

  As described above, when one target is detected in each phase, it is possible to calculate the target relative speed and relative distance. However, as shown in FIG. 24 to be described later, when a plurality of detections are made in each phase (two targets, one JEM is detected for each), the above-described method calculates an accurate target relative speed and relative distance. Can not do it.

  Therefore, a method for accurately calculating the relative speed and relative distance of the target when a plurality of detections are made in each phase (two targets, one JEM is detected) will be described next. When a plurality of target candidates are detected in each phase, the target candidate detection unit 207B calculates the relative speed and relative distance of the target candidates from the combination of target candidates detected in each phase.

  FIG. 23 is an explanatory diagram showing a situation when there are two targets and JEMs in each phase at time t and time t−Δt in the fourth embodiment of the present invention. Here, in the case shown in FIG. 23, a method for calculating the relative speed and the relative distance of the target candidate by the target candidate detecting unit 207B will be described.

  FIG. 24 is an explanatory diagram showing a case where two targets and JEM are detected in each phase at time t in Embodiment 4 of the present invention. Using the case of FIG. 24 as an example, a method for calculating the relative speed and relative distance of the target candidate by the target candidate detecting means 207B for the case of a plurality of targets will be described.

  When there are a plurality of target candidates in each phase, the target candidate detection unit 207B calculates a relative distance from the combination of target candidates detected in each phase, and detects the relative speed and relative distance of the target candidate as a second target candidate. Output to means 213.

FIG. 25 is a diagram illustrating a distance measurement result calculated from a combination when two targets and JEM are detected in each phase at time t in Embodiment 4 of the present invention. More specifically, FIG. 25A shows a relative distance calculated from a combination of target candidates detected in the speed measurement phase and the distance measurement 1 phase at time t. Here, R ₀₁ ″ (f _{v, T 1} , f _{R 1, T 1} ) is the target candidate frequency f _{v, T} 1 detected in the speed measurement phase and the target candidate frequency f _R 1 detected in the distance measurement phase 1 _{; This} is a distance measurement result calculated from the combination of _T1 using the above equation (45), and other combinations can be calculated in the same manner.

On the other hand, FIG. 25B shows a relative distance calculated from a combination of target candidates detected in the speed measurement phase and the distance measurement 2 phase at time t. Here, R ₀₂ ″ (f _{v, T 1} , f _{R 1, T 1} ) is a target candidate frequency f _{v, T 1} detected in the speed measurement phase and a target candidate frequency f _R 2 detected in the distance measurement phase _{2, This} is a distance measurement result calculated from the combination of _T1 using the above equation (47), and other combinations can be calculated in the same manner.

  Calculated only from the relative distance calculated from the combination of target candidates detected in the speed measurement phase and ranging 1 phase at time t, or from the combination of target candidates detected in the speed measurement phase and ranging 2 phase at time t Only with the relative distance, the relative distance with respect to the relative speed of the target candidate calculated in the speed measurement phase cannot be determined.

Therefore, the second target candidate detection means 213 calculates the relative distance calculated from the combination of the target candidate frequencies f _{v and T1} detected in the speed measurement phase at time t and the target candidates detected in the distance measurement 1 phase, and the time The difference between the frequency _{fv and T1} of the target candidate detected in the speed measurement phase of t and the relative distance calculated from the combination of the target candidates detected in the distance measurement 2 phase is calculated.

FIG. 26 shows the results of distance measurement in the speed measurement phase fv _{, T1} and the distance measurement 1 phase, and the speed measurement phase _{fv, T1} and the distance measurement 2 phase in Embodiment 4 of the present invention. It is explanatory drawing for calculating the relative distance of a target candidate from the difference of a ranging result. When the difference is equal to or smaller than a predetermined value, the second target candidate detection unit 213 determines a target candidate at a relative distance of relative speed f _{v and T1} . Here, | X | represents the absolute value of the variable X. For other relative velocities, the relative distance can be calculated by the same method.

  Thus, even when a plurality of target candidates are detected in each phase, it is possible to calculate the relative speed and relative distance of the target candidates. Also at the time t−Δt, it is possible to obtain the target candidate's relative speed and relative distance by the same method. However, when target candidates having different relative velocities at the same relative distance are calculated, it is not possible to determine whether the target is JEM or acceleration based on the result of only time t or only time t−Δt.

  For this reason, the fourth embodiment uses the distance-speed estimated value calculation means 208, the target determination means 209, and the second target determination means 210 as in the first embodiment, and uses the JEM, the acceleration target, and the like. , Target, JEM, and target candidate not determined as any of the acceleration targets are identified. Also, when using the result of time t and time t + Δt, it is possible to identify similarly.

  In the above description, the target candidate detection unit 207B and the second target candidate detection unit 213 are described as separate components. However, the target candidate detection unit 207B includes the functions of the second target candidate detection unit 213. It is also possible to implement the configuration.

  As described above, according to the fourth embodiment, even when the distance-speed map creating means is not used as in the first to third embodiments, the speed measurement phase for transmitting / receiving different carrier frequencies, the distance measurement 1 It is possible to calculate the target relative speed and relative distance using the phase and the distance measuring 2 phase as in the first to third embodiments. Further, in the speed measurement phase, speed measurement can be performed with high accuracy.

  In addition, even when there are a plurality of target candidates, the second candidate determination unit is used for the target candidates that are not determined as targets by the target determination unit, using the JEM, the acceleration target, the target, the JEM, It has a configuration for identifying three types of target candidates that are not determined as any of the acceleration targets. As a result, the acceleration target is not erroneously detected as JEM and removed, and a radar apparatus with improved target detection performance can be obtained.

  1 Antenna 2, 2, 2B Transmitter, 3 Transmission / Reception Switch, 4, 4B Receiver, 5 Signal Processor, 20 Display, 205A, 205B, 205C, 205D Signal Processor, 206 Speed Map Generation Unit, 207, 207B Target Candidate detection means, 208, 208B Speed estimated value calculation means, 209, 209B Target determination means, 210, 210B Second target determination means, 211 Speed aliasing number calculation means, 212 Frequency domain conversion means, 213 Second target candidate detection Means (target candidate detection means).

Claims (7)

A radar apparatus that calculates a relative distance and a relative speed with respect to a target and performs target detection,
Transmitting means for emitting a transmission signal in which a carrier signal is pulse-modulated at a predetermined time interval;
Receiving means for receiving the transmission signal reflected and returned by the target as a reception signal;
A distance-speed map creating means for creating a distance-speed map for calculating a target relative distance and a relative speed from the received signal received by the receiving means;
For the distance-speed map created by the distance-speed map creating means based on the received signal received at the first time, a target candidate at the first time is detected based on the signal strength, and the target Target candidate detection means for calculating relative distance and relative speed with the candidate;
A velocity estimation value calculating means, - the target candidate detected by the detecting means that said target candidate, the distance in the second time is the time of the predetermined time before the first time - the distance to calculate a range of velocity estimates
The target candidate detected by the target candidate detecting means based on the distance-speed map at the second time is the distance-speed estimation at the second time of the target candidate calculated by the distance-speed estimated value calculating means. A target determination unit that determines that the target candidate detected at the first time is a target if it exists within a range of values;
The target candidate detected by the target candidate detecting means based on the distance-speed map at the second time is the distance-speed estimation at the second time of the target candidate calculated by the distance-speed estimated value calculating means. If it is not within the range of the value and is within the range of the distance-speed estimated value at the second time of the JEM calculated by the distance-speed estimated value calculating means, it is detected at the first time. The determined target candidate is determined as JEM, and the second target candidate is set as the second target candidate except the target candidate determined as JEM and the target candidate determined as the target by the target determination unit. A radar apparatus comprising: a determination unit. The radar apparatus according to claim 1, wherein
The second target determination means is detected by the target candidate detection means at the first time and the target candidate detection means at the second time among the second target candidates. If the calculated target acceleration is assumed to be the same target, and the calculated acceleration is within a predetermined acceleration range, the target candidate detected at the first time is determined as an acceleration target. The radar apparatus according to claim 1, wherein the acceleration target is further removed from the second target candidates to form a new second target candidate. The radar apparatus according to claim 1 or 2,
A speed at which the target candidate speed wrapping number is calculated using the relative distance and the relative speed calculated by the target candidate detecting means, and the target candidate relative speed is calculated in consideration of the calculated speed wrapping number. It further comprises a folding number calculation means,
The distance-speed estimated value calculating means calculates the target candidate detected by the target candidate detecting means based on the relative speed of the target candidate considering the speed return number calculated by the speed return number calculating means. A range of a distance-speed estimated value at a second time is calculated. A radar apparatus that calculates a relative distance and a relative speed with respect to a target and performs target detection,
Transmitting means for emitting a transmission signal in which a carrier signal is pulse-modulated at a predetermined time interval;
Receiving means for receiving the transmission signal reflected and returned by the target as a reception signal;
A distance-speed map creating means for creating a distance-speed map for calculating a target relative distance and a relative speed from the received signal received by the receiving means;
For the distance-speed map created by the distance-speed map creating means based on the received signal received at the first time, a target candidate at the first time is detected based on the signal strength, and the target Target candidate detection means for calculating relative distance and relative speed with the candidate;
A distance-speed estimated value calculating means for calculating a range of a distance-speed estimated value at a third time after a predetermined time has elapsed from the first time of the target candidate detected by the target candidate detecting means;
The target candidate detected by the target candidate detecting means based on the distance-speed map at the third time is the distance-speed estimation at the third time of the target candidate calculated by the distance-speed estimated value calculating means. A target determination unit that determines the target candidate detected at the third time as a target when the value is within a range of values;
The target candidate detected by the target candidate detecting means based on the distance-speed map at the third time is the distance-speed estimation at the third time of the target candidate calculated by the distance-speed estimated value calculating means. If it is not within the range of the value and is within the range of the distance-speed estimated value at the third time of JEM calculated by the distance-speed estimated value calculating means, it is detected at the third time. The determined target candidate is determined as JEM, and the second target candidate is set as the second target candidate except the target candidate determined as JEM and the target candidate determined as the target by the target determination unit. A radar apparatus comprising: a determination unit. The radar apparatus according to claim 4, wherein
The second target determination means is detected by the target candidate detection means at the first time and the target candidate detection means at the third time among the second target candidates. If the calculated target acceleration is assumed to be the same target, and the calculated acceleration is within a predetermined acceleration range, the target candidate detected at the third time is determined as an acceleration target. The radar apparatus according to claim 1, wherein the acceleration target is further removed from the second target candidates to form a new second target candidate. The radar apparatus according to claim 1 or 4,
The transmission means radiates the transmission signal in a time division manner in three phases of a speed measurement phase, a distance measurement 1 phase, and a distance measurement 2 phase. In the speed measurement phase, a carrier signal having a constant frequency is a predetermined frequency. A transmission signal that is pulse-modulated at a time interval is emitted, and in the ranging 1 phase, a carrier signal that is frequency-modulated is a transmission signal that is pulse-modulated at a predetermined time interval, and in the ranging 2 phase Radiating a transmission signal in which a carrier signal modulated at a frequency different from that of the ranging 1 phase is pulse-modulated at a predetermined time interval;
The frequency domain converting means provided instead of the distance-speed map creating means converts the time domain received signal received by the receiving means into the frequency domain,
The target candidate detecting means includes
Performing arithmetic processing based on the intensity of the signal in the frequency domain received signal transformed by the frequency domain transforming means, and detecting the target candidate at the first time in the speed measurement phase and relative to the target candidate A speed is calculated, and in the ranging 1 phase and ranging 2 phase, a target candidate at the first time is detected, and a relative distance to the target candidate or a frequency corresponding to the relative distance is calculated. Radar device. The radar apparatus according to claim 6, wherein
The target candidate detecting means, when detecting a plurality of target candidates in the three phases, calculates a first relative distance corresponding to a combination of target candidates detected in each of the speed measurement phase and the ranging 1 phase. And calculating a second relative distance corresponding to a combination of target candidates detected in each of the speed measurement phase and the distance measurement 2 phase,
Based on the difference between the first relative distance and the second relative distance, the target candidate at the first time is specified, and the relative speed and relative distance with the specified target candidate are calculated. Radar device.

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