Radar device

Abstract

A radar device according to the present disclosure is provided with: an LPRF radar device (1000) that irradiates LPRF radio waves toward the atmosphere and receives reflected waves reflected by a target; and an HPRF radar device (2000) that irradiates HPRF radio waves toward the atmosphere and receives reflected waves reflected by a target, the LPRF radar device (1000) and the HPRF radar device (2000) each include a signal processing system (700) having an LPRF system and an HPRF system, and the radar device is further provided with a target detection processing unit (3000) that detects the target from the LPRF radar device (1000) and the HPRF radar device (2000). And a target detection processing unit (3000) that detects the position and speed of the target on the basis of information transmitted from the signal processing system (1-700) of the LPRF radar device (1000) and information transmitted from the signal processing system (2-700) of the HPRF radar device (2000).

Description

Technical Field

[0001] The disclosed technology relates to a radar device. Background Art

[0002] In the technical field of radar devices, there are known technologies for improving the detection rate and reducing the false detection rate. For example, Patent Document 1 discloses the following: when measuring distance and speed, a signal modulated by a pulse sequence coded signal is sent, and the received signal is correlated with a reference signal of each of a plurality of speeds, and the speed of the reference signal whose correlation output exceeds a predetermined critical point and the position based on the correlation result are output as the distance.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-182010 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In detecting a target, it is considered to make a plurality of radar devices cooperate. In particular, if a plurality of radar devices are made to cooperate so that the radio waves generated by each radar device have different PRFs, it is expected that the target (Tgt) detection with strong noise resistance based on multiple information can be compared with the detection of the target using the radio waves of a certain PRF. However, as far as the inventor knows, there is no document that discloses how to make a plurality of radar devices cooperate.

[0008] Means used to solve problems

[0009] The radar device of the disclosed technology includes: an LPRF radar device, which irradiates LPRF radio waves toward the atmosphere and receives reflected waves reflected by a target; and an HPRF radar device, which irradiates HPRF radio waves toward the atmosphere and receives reflected waves reflected by a target, the LPRF radar device and the HPRF radar device respectively include a signal processing system having an LPRF system and an HPRF system, and the radar device also includes a target detection processing unit, which detects the position and speed of the target based on information sent from the signal processing system of the LPRF radar device and information sent from the signal processing system of the HPRF radar device.

[0010] Effects of the Invention

[0011] Since the radar device of the disclosed technology has the above structure, it is possible to make multiple radar devices such as the radio waves generated by each radar device have different PRFs to cooperate. Due to this effect, the radar device of the disclosed technology can detect a target (Tgt) with strong noise resistance based on multiple information, compared with detecting a target using a radio wave of a certain PRF. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a block diagram illustrating the functional structure of the radar device according to the disclosed technology.

[0013] Figure 2 1 is a block diagram illustrating a functional configuration of a receiving system 600 employed in a radar device according to the disclosed technology.

[0014] Figure 3 1 is a block diagram illustrating a functional structure of a signal processing system 700 used in a radar device according to the disclosed technology.

[0015] Figure 4 This is an explanatory diagram showing a method of the integration processing unit 760 in the radar device according to the first embodiment.

[0016] Figure 5 This is an explanatory diagram for explaining the azimuth angle and elevation angle.

[0017] Figure 6 This is an explanatory diagram showing the processing contents of the range-speed map generation unit 740 - 1 in the radar device according to the first embodiment.

[0018] Figure 7 This is an explanatory diagram showing the processing contents of the range-speed map generation unit 740 - 2 in the radar device according to the first embodiment.

[0019] Figure 8 1 is an explanatory diagram showing speed axis correction as the processing content of the interpolation processing unit 750 in the radar device according to the first embodiment.

[0020] Fig. 9 This is an explanatory diagram showing range axis correction as the processing content of the interpolation processing unit 750 in the radar device according to the first embodiment.

[0021] Fig.10 This is an example of a range-speed map obtained by the radar device of the disclosed technology.

[0022] Fig.11 This is a flowchart showing a grouping processing procedure performed by the target detection processing unit 3000 in the radar device according to the first embodiment.

[0023] Fig.12This is an explanatory diagram showing a grouping processing procedure performed by the target detection processing unit 3000 in the radar device according to the first embodiment.

[0024] Fig.13 This is an explanatory diagram showing the configuration of some functional blocks in the radar device according to the second embodiment.

[0025] Fig.14 This is an explanatory diagram showing a form of some functional blocks in the radar device according to the third embodiment.

[0026] Fig.15 This is a block diagram showing a detailed functional configuration of the pulse compression unit 730 ( 730 -F) in the radar device according to the third embodiment.

[0027] Fig.16 This is an explanatory diagram (part 1) showing a form of some functional blocks in a radar device according to a fourth embodiment.

[0028] Fig.17 This is an explanatory diagram (part 2) showing a form of some functional blocks in the radar device according to the fourth embodiment.

[0029] Fig.18 This is an explanatory diagram showing a form of some functional blocks in the radar device according to the fifth embodiment.

[0030] Fig.19 This is a block diagram showing a detailed functional configuration of the integration processing unit 760 in the radar device according to the fifth embodiment.

[0031] Fig. 20 This is an explanatory diagram showing a time series of a situation in which the radar apparatus according to the fifth embodiment performs transmission and reception over a plurality of CPIs.

[0032] Fig.21 This is an explanatory diagram showing the configuration of some functional blocks in a radar device according to a sixth embodiment.

[0033] Fig. 22 This is a range-speed map for explaining the case where the radar device of the sixth embodiment sets the ambiguity range. DETAILED DESCRIPTION

[0034] Implementation method 1.

[0035] Figure 1 is a block diagram illustrating the functional structure of the radar device of the disclosed technology. Figure 1As shown in FIG. 1 , the radar device of the disclosed technology is composed of an LPRF radar device 1000, an HPRF radar device 2000, and a target detection processing unit 3000. LPRF refers to Low Pulse Repetition Frequency. The distance ambiguity of LPRF is small, so it is suitable for observing the distance of the target (Tgt). In addition, HPRF refers to High Pulse Repetition Frequency. The speed ambiguity of HPRF is small, so it is suitable for observing the speed of the target (Tgt).

[0036] The LPRF radar device 1000 includes three systems: an LPRF radar transmission system 100, a reception system 600, and a signal processing system 700. Figure 1 In the specification, "1-" is added before the reference numerals of the receiving system 600 and the signal processing system 700 in the LPRF radar device 1000. In the present specification, when emphasizing that they are components in the LPRF radar device 1000, "1-" is added before the reference numerals, such as "1-600" and "1-700".

[0037] The HPRF radar device 2000 includes three systems: an HPRF radar transmission system 200, a reception system 600, and a signal processing system 700. Figure 1 In the present specification, "2-" is added before the reference numerals of the receiving system 600 and the signal processing system 700 in the HPRF radar device 2000. In the present specification, "2-" is added before the reference numerals, such as "2-600" and "2-700", when emphasizing that they are components in the HPRF radar device 2000.

[0038] Figure 1 The thick wavy arrow in shows that the LPRF pulse generated by the LPRF transmitter 110 is transmitted toward the target (Tgt) through the LPRF transmission antenna 120.

[0039] Figure 1 The thin wavy arrow in φ indicates the LPRF pulse reflected by the target (Tgt) (hereinafter referred to as “LPRF reflected wave”). The LPRF reflected wave is received by the receiving systems 600 ( 1 - 600 , 2 - 600 ) of the LPRF radar device 1000 and the HPRF radar device 2000 .

[0040] Figure 1 The thick wavy dashed arrow in illustrative figures shows that the HPRF pulse generated by the HPRF transmitter 210 is transmitted toward the target (Tgt) through the HPRF transmission antenna 220 .

[0041] Figure 1The thin wavy dashed arrow in shows the HPRF pulse reflected by the target (Tgt) (hereinafter referred to as “HPRF reflected wave”). The HPRF reflected wave is received by the receiving systems 600 (1-600, 2-600) of the LPRF radar device 1000 and the HPRF radar device 2000, respectively.

[0042] like Figure 1 As shown, the LPRF radar transmission system 100 includes an LPRF transmitter 110 and an LPRF transmission antenna 120 .

[0043] like Figure 1 As shown, the HPRF radar transmission system 200 includes an HPRF transmitter 210 and an HPRF transmission antenna 220 .

[0044] Figure 2 6 is a block diagram illustrating the functional structure of a receiving system 600 used in a radar device of the present disclosure. Figure 1 As shown, the receiving system 600 used in the radar device of the disclosed technology is included in the LPRF radar device 1000 and the HPRF radar device 2000, respectively. The receiving systems 600 (1-600, 2-600) included respectively may also have the same structure.

[0045] like Figure 2 As shown, the receiving system 600 includes an element antenna 610, a beam forming unit 620, a band pass filter 630, a receiver 640 (640-1, 640-2), and a mixing unit 650 (650-1, 650-2). Figure 2 As shown, the receiving system 600 is divided into an LPRF system and an HPRF system from the back stage of the bandpass filter 630 to the output. The structural elements in the LPRF system are a receiver 640-1 and a mixer 650-1. The structural elements in the HPRF system are a receiving system 600-2 and a mixer 650-2.

[0046] Figure 3 7 is a block diagram illustrating the functional structure of a signal processing system 700 used in a radar device of the present disclosure. Figure 3 As shown, the signal processing system 700 includes an AD converter 710 (710-1, 710-2), a pulse hitting direction processing unit 720 (720-1, 720-2), a pulse compression unit 730 (730-1, 730-2), a distance speed map generation unit 740 (740-1, 740-2), an interpolation processing unit 750, an integration processing unit 760, and a comparison processing unit 770. Figure 1As shown, the signal processing system 700 used in the radar device of the disclosed technology is included in the LPRF radar device 1000 and the HPRF radar device 2000 respectively, and the signal processing systems 700 (1-700, 2-700) respectively included may also have the same structure.

[0047] like Figure 3 As shown, the signal processing system 700 is divided into an LPRF system and an HPRF system from the front stage of the input to the interpolation processing unit 750. The structural elements of the LPRF system are an AD converter 710-1, a pulse hit direction processing unit 720-1, a pulse compression unit 730-1, and a distance speed map generation unit 740-1. The structural elements of the HPRF system are an AD converter 710-2, a pulse hit direction processing unit 720-2, a pulse compression unit 730-2, and a distance speed map generation unit 740-2.

[0048] Figure 4 1 is an explanatory diagram showing the method of the integration processing unit 760 in the radar device of the first embodiment. Figure 4 As shown, the radar device of Embodiment 1 may also perform PDI (Post Detection Integration) by the integration processing unit 760. More specifically, in the radar device of Embodiment 1, the integration processing unit 760 performs incoherent integration, that is, frequency domain integration, on the range-velocity map sent from the interpolation processing unit 750.

[0049] <Beamforming Unit 620 Constituting Reception System 600>

[0050] The beamforming unit 620 constituting the reception system 600 is a component that separates the signal received by the element antenna 610 into a plurality of regions defined by azimuth angles and elevation angles.

[0051] Figure 5 This is an explanatory diagram for explaining the azimuth angle and elevation angle. Figure 5 As shown, the space is represented by a left-handed XYZ coordinate system, and the beam direction is represented by an azimuth angle and an elevation angle.

[0052] exist Figure 5 The azimuth of the beam is represented by the character θ az (n az ) represents. Here, the parameter n az It is the number marked on the azimuth, ranging from 1 to N az That is, the radar device of the disclosed technology predefines N az different azimuth angles.

[0053] exist Figure 5 In the example, the elevation angle of the beam is represented by the character θ el (nel ) represents. Here, the parameter n el It is the number marked on the elevation angle, ranging from 1 to N el That is, the radar device of the disclosed technology predefines N el Different elevation angles.

[0054] The beam forming unit 620 outputs a signal (s j，naz，nel The signal (s) outputted from the beam forming unit 620 j，naz，nel (t)) is sent to the bandpass filter 630.

[0055] <Bandpass filter 630 constituting receiving system 600>

[0056] The bandpass filter 630 constituting the receiving system 600 is a signal (s j，naz，nel (t)) into the structural elements of the LPRF system and the HPRF system. Specifically, the bandpass filter 630 is composed of the frequency bands (B 1 ) and the frequency band of the HPRF pulse (B 2 ) of the bandpass filter (B 1 Use and B 2 Use) to form.

[0057] In the bandpass filter 630, the frequency band (B 1 ) is sent to the receiver 640-1. In the subsequent stage of the receiver 640-1, it can be considered that the same processing as the radar device of the prior art is implemented. 1 )'s signal component ends up in Figure 3 The pulse compression unit 730-1 shown in FIG. 1 becomes a range Doppler signal (s rd1 ), is sent to the range-speed map generation unit 740-1. In addition, in the character s representing the range Doppler signal rd1 In the above equation, the subscript rd comes from the first letter of the English word range doppler, and the subscript 1 indicates that it is an LPRF system. az 、n el Generate range Doppler signals (s rd1 ).

[0058] In the bandpass filter 630, the frequency band (B 2 ) is sent to the receiver 640-2. At the subsequent stage of the receiver 640-2, it can be considered that the same processing as the radar device of the prior art is performed. 2 )'s signal component ends up in Figure 3The pulse compression unit 730-2 shown in FIG. 7 is a range Doppler signal (s rd2 ), and is sent to the distance-speed map generation unit 740-2. az 、n el Generate range Doppler signals (s rd2 ).

[0059] <<Range-speed map generation unit 740-1 of the LPRF system constituting the signal processing system 700>>

[0060] The range-velocity map generator 740-1 of the LPRF system constituting the signal processing system 700 is a component for generating a range-velocity map. When generating the range-velocity map, the range-velocity map generator 740-1 of the LPRF system considers the ambiguity of the Doppler velocity (hereinafter referred to as “velocity ambiguity”). amb )”).

[0061] In the nth d The velocity of the target (Tgt) associated with the target signal of the Doppler bin is v 1 (n d ), including velocity ambiguity (v amb ) can be represented by the following formula: 1 .

[0062]

[0063] Here, n is an integer. In formula (1), c represents the speed of light, and f 1 represents the transmission frequency of the LPRF radar device 1000, T LPRI represents the pulse repetition period of the LPRF pulse. In addition, the horizontal bar used as an accent mark in equation (1) represents the value related to the real image without blur. From another point of view, equation (1) represents the velocity blur (v amb ) occurs at regular intervals. In addition, the details of the ghosting shown in formula (1) are described later. Fig.10 and Fig.12 The description becomes clear.

[0064] The range-velocity map generation unit 740-1 of the LPRF system considers the velocity ambiguity (v amb ) and performs processing such as connecting the distance-speed mapping.

[0065] Figure 6 This is an explanatory diagram showing the processing contents of the range-speed map generation unit 740 - 1 in the radar device according to the first embodiment.

[0066] Figure 6 The upper layer shows that considering the velocity ambiguity (vamb ) is set by the size of the Doppler bin (n d , 1 to N d1 ).

[0067] Figure 6 The middle layer of shows the situation that the distance-speed map generation unit 740-1 of the LPRF system connects the distance-speed map. Figure 6 The double-arrowed line segment in the middle layer of the "assumed target speed range" indicates the range of speeds that the pre-assumed target (Tgt) can take, as described in the text. The minimum value (N) of n in equation (1) is determined based on the range of speeds that the pre-assumed target (Tgt) can take. min ) and the maximum value (N max ).

[0068] Figure 6 The lower layer shows the new distance speed map (M) obtained by connecting rd1 ) Redefine the Doppler bin number (in Figure 6 Regarding the Doppler bin number (n d ), and are arranged in ascending order of speed as 1, 2, ..., N d1 .

[0069] The new range-speed map (M) generated by the range-speed map generation unit 740-1 of the LPRF system rd1 ) is sent to the interpolation processing unit 750.

[0070] <<Range-velocity map generation unit 740-2 of the HPRF system constituting the signal processing system 700>>

[0071] The range-velocity map generation unit 740-2 of the HPRF system constituting the signal processing system 700 is a component for generating a range-velocity map. When generating the range-velocity map, the range-velocity map generation unit 740-2 of the HPRF system considers the ambiguity of the distance (also called range) (hereinafter referred to as “range ambiguity (r amb )”).

[0072] In the nth r The distance of the target (Tgt) associated with the target signal of the range bin is r 2 (n r ), including the range ambiguity (r amb ) can be represented by the following formula in principle. 2 .

[0073]

[0074] Here, n is an integer. c in formula (2) represents the speed of light, T HPRI represents the pulse repetition period of the HPRF pulse. The horizontal bar used as an accent mark in equation (2) represents the value related to the real image without ambiguity. From another point of view, equation (2) represents the range ambiguity (r amb ) occurs at regular intervals. In addition, the details of the ghosting shown in equation (2) are described later. Fig.10 and Fig.12 The description becomes clear.

[0075] The range velocity map generation unit 740-2 of the HPRF system considers the range ambiguity (r amb ) to connect the distance-speed mapping.

[0076] Figure 7 This is an explanatory diagram showing the processing contents of the range-speed map generation unit 740 - 2 in the radar device according to the first embodiment.

[0077] Figure 7 The left column shows the range ambiguity (r amb ) is set by the size of the distance bin (n r , 1 to N r2 ).

[0078] Figure 7 The middle column of shows the situation where the distance-speed map generation unit 740-2 of the HPRF system connects the distance-speed map. Figure 7 The double-arrowed line segment in the middle column, which is recorded as "assumed target distance range", indicates the range of the distance (range) that the target (Tgt) can take in advance. The minimum value (N) of n in equation (2) is determined based on the range of the distance (range) that the target (Tgt) can take in advance. min ) and the maximum value (N max ).

[0079] Figure 7 The right column shows the new distance-speed mapping (M rd2 ) Redefine the distance bin number (in Figure 7 Regarding the distance bin number (n r ), and are arranged in order from near to far as 1, 2, ..., Nr2

[0080] The new range-speed map (M) generated by the range-speed map generation unit 740-2 of the HPRF system rd2 ) is sent to the interpolation processing unit 750.

[0081] <<Interpolation Processing Unit 750 Constituting Signal Processing System 700>>

[0082] The interpolation processing unit 750 constituting the signal processing system 700 is a component that performs processing for interpolating and correcting the range bins and Doppler bins in the range-velocity map in consideration of information obtained by the LPRF system and information obtained by the HPRF system.

[0083] Figure 8 1 is an explanatory diagram showing speed axis correction as the processing content of the interpolation processing unit 750 in the radar device according to Embodiment 1. Fig. 9 This is an explanatory diagram showing range axis correction as the processing content of the interpolation processing unit 750 in the radar device according to the first embodiment.

[0084] Figure 8 The upper layer shows the new distance-speed map (M) generated by the distance-speed map generation unit 740-1 of the LPRF system. rd1 ) and the new range-speed map (M) generated by the range-speed map generation unit 740-2 of the HPRF system rd2 ), there may be differences in the Doppler bins.

[0085] Figure 8 The lower layer is to set the horizontal axis to the distance speed map (M) generated by the LPRF system. rd1 ) of the Doppler bin, and the vertical axis is set to the range velocity map (M) generated by the HPRF system. rd2 ) and plotted to show their correlation. Figure 8 The lower layer, the straight line recorded as "linear approximation straight line" shows the distance velocity map (M) generated by the LPRF system. rd1 ) and the range velocity map (M) generated by the HPRF system rd2 ) there is a correlation between the Doppler bins that can be approximated as linear.

[0086] The interpolation processing unit 750 constituting the signal processing system 700 can set the correlation represented by the linear approximation straight line to be positive, and can appropriately interpolate and correct the Doppler bins in the range-velocity map.

[0087] Fig. 9 The upper layer shows the new distance-speed map (M) generated by the distance-speed map generation unit 740-1 of the LPRF system. rd1 ) and the new range-speed map (M) generated by the range-speed map generation unit 740-2 of the HPRF system rd2 ), the distance bins may differ.

[0088] Fig. 9The lower layer is to set the horizontal axis to the distance speed map (M) generated by the LPRF system. rd1 ) range bin, and the vertical axis is set to the range velocity map (M) generated by the HPRF system. rd2 ) are plotted to show their correlation. Fig. 9 The straight line recorded as “linear approximation straight line” at the lower level shows the distance velocity map (M) generated by the LPRF system. rd1 ) and the range-velocity map (M) generated by the HPRF system rd2 ) exists between the distance bins that can be approximated as linear.

[0089] The interpolation processing unit 750 constituting the signal processing system 700 can set the correlation represented by the linear approximation straight line to be positive, and can appropriately interpolate and correct the range bins in the range-speed map.

[0090] The distance-speed map interpolated and corrected in the interpolation processing unit 750 is sent to the integration processing unit 760 .

[0091] <<Integral processing unit 760 constituting signal processing system 700>>

[0092] In the technical field related to signal processing of radar devices, integration processing is often used for the purpose of improving the SN ratio. The integration processing unit 760 constituting the signal processing system 700 is a component that performs integration processing to improve the SN ratio.

[0093] As described above, the integration processing unit 760 of the first embodiment applies PDI to the distance-speed map. In this specification, the distance-speed map to which PDI is applied is referred to as a PDI signal (p rd ), which is distinguished from the distance-speed mapping before PDI is implemented. rd ) can also be considered as n r 、n d 、n az and n el is a function of the parameters. rd ) is given by the following formula, for example.

[0094] p rd (n r , n d , n az , n el )=∑M rd1 (n r , n d , n az , n el )+∑M rd2 (n r , n d , naz , n el )

[0095] or

[0096] p rd (n r , n d , n az , n el )=|M rd1 (n r , n d , n az , n el )| 2 +|M rd2 (n r , n d , n az , n el )| 2 ...(3)

[0097] Here, in the lower layer of equation (3), based on the relationship that the square of the signal amplitude represents the power, the PDI signal (p rd ).

[0098] The PDI signal (p rd ) is sent to the comparison processing unit 770.

[0099] <Comparison Processing Unit 770 Constituting Signal Processing System 700>

[0100] The comparison processing unit 770 constituting the signal processing system 700 is a component that performs the integration processing on the signal (in the first embodiment, the PDI signal (p rd )) is compared with a preset threshold (also called a critical point) to determine whether it is a target signal regarding the target (Tgt) or a useless signal.

[0101] The comparison processing unit 770 compares the PDI signals (p rd In the comparison processing unit 770, the PDI signal (p rd ) components are sent to the target detection processing unit 3000 as candidates for target signals.

[0102] As mentioned above, the PDI signal (p rd ) is considered to be n r 、n d 、n az and n el is a function of parameters. In the detection of the target (Tgt), at what n r 、nd 、n az and n el When PDI signal (p rd ) exceeds the threshold value. Therefore, the comparison processing unit 770 converts the PDI signal (p rd ) exceeds the threshold value r 、n d 、n az and n el For example, record as a construct.

[0103] The signal processing system 700 (1-700) in the LPRF radar device 1000 defines a structure (X) as follows, for example. 1 )

[0104]

[0105] Here, k 1 is a variable used in the signal processing system 700 (1-700), K 1 is the PDI signal (p rd ) exceeds the total number of threshold components. 1 ) in the elements (also called fields), in addition to the elements shown in formula (4), the kth 1 p exceeds the threshold rd The value of .

[0106] The structure (X) obtained by the signal processing system 700 (1-700) 1 ) information and PDI signal (p rd ) is sent to the target detection processing unit 3000 together with the information.

[0107] Similarly, the signal processing system 700 (2-700) in the HPRF radar device 2000 defines the following structure (X 2 )

[0108]

[0109] Here, k 2 is a variable used in the signal processing system 700 (2-700), K 2 is the PDI signal (p rd ) exceeds the total number of threshold components. 2 ) in the elements (also called fields), in addition to the elements shown in formula (5), the kth 2 p exceeds the threshold rd The value of .

[0110] The structure (X) obtained by the signal processing system 700 (2-700) 2 ) information and PDI signal (p rd ) is sent to the target detection processing unit 3000 together with the information.

[0111] 《Target Detection Processing Unit 3000》

[0112] The target detection processing unit 3000 is a component that detects a target (Tgt) based on information sent from the signal processing system 700 ( 1 - 700 ) of the LPRF radar device 1000 and information sent from the signal processing system 700 ( 2 - 700 ) of the HPRF radar device 2000 .

[0113] The processing performed by the object detection processing unit 3000 can be roughly divided into two types. The first is the confirmation of the correspondence relationship. The second is a process called "2-in-1 detection".

[0114] The confirmation of the correspondence relationship performed by the target detection processing unit 3000 is a process of comparing the structure (X) sent from the signal processing system 700 (1-700) in the LPRF radar device 1000 with the structure (X 1 ) and the structure (X) sent from the signal processing system 700 (2-700) in the HPRF radar device 2000 2 ) information, confirm the record in which a certain same target (Tgt) appears in each structure, and confirm their corresponding relationship.

[0115] For example, suppose that in comparing the constructs (X 1 ) 1 = 10 records (X 1 (10)) and the structure (X 2 ) 2 =12 records (X 2 (12)), each of the four elements (n r 、n d 、n az and n el ) are roughly the same. At this time, the target detection processing unit 3000 considers that the structure (X 1 ) 1 = 10 records and structures (X 2 ) 2 = 12 records are records about the same target (Tgt) and they are made to correspond.

[0116] When the target (Tgt) is located far enough from the distance between the LPRF radar device 1000 and the HPRF radar device 2000, the structure (X 1 ) and the structure (X 2 ) shows roughly the same trend.

[0117] The confirmation of the correspondence relationship performed by the target detection processing unit 3000 may be performed in conjunction with the tracking function of the radar device.

[0118] The "2-in-1 detection" performed by the target detection processing unit 3000 refers to processing in such a way that a target (Tgt) detected by only one of the two radar devices, the LPRF radar device 1000 and the HPRF radar device 2000, can also be output as a detection result. Specifically, the target detection processing unit 3000 collects the structure (X 1 ) and the construct (X 2 Here, the structure produced by this combination is called X ADD In the above example, the structure (X 1 ) 1 = 10 records and structures (X 2 ) 2 = 12 records are records about the same target (Tgt). In this case, in the structure (X ADD ), records about the same target (Tgt) are aggregated into 1.

[0119] In this way, the object detection processing unit 3000 performs the confirmation of the correspondence relationship and the "2 in 1 detection" process to generate a structure (X ADD ). The structure (X) generated by the object detection processing unit 3000 ADD ) includes information about a target (Tgt) detected by only one of the two radar devices, the LPRF radar device 1000 and the HPRF radar device 2000.

[0120] Fig.10 This is an example of a range-velocity map obtained by the radar device of the present disclosure. ADD ), when extracting az and n el The records of the groups are plotted (n r , n d ) point, we get Fig.10 An illustrated range-speed map. Fig.10The range-velocity map shown in the example is a range-velocity map when a certain target (Tgt) is assumed. The radar device of the disclosed technology can use the velocity ambiguity (v amb ) and the distance ambiguity (r amb ) information, and grouping the plurality of plots appearing in the distance-speed map as plots originating from a certain target (Tgt). The grouping process is implemented by the target detection processing unit 3000.

[0121] Fig.11 : is a flowchart showing the grouping processing procedure performed by the target detection processing unit 3000 in the radar device of Embodiment 1. Fig.12 1 is an explanatory diagram showing a grouping processing procedure performed by the target detection processing unit 3000 in the radar device according to the first embodiment.

[0122] exist Fig.11 The step indicated as S1 in FIG. 1 is a processing step for initializing a variable (k) used in the processing of grouping. In S1, the variable (k) is substituted with an initial value of 1.

[0123] When the processing step is at the S1 stage, the distance speed map is Fig.12 (a) shows the state. Fig.12 In the example shown in (a), there are 16 plots exceeding the threshold value in the distance-speed map.

[0124] exist Fig.11 The step denoted as S2 in the figure is based on the range ambiguity (r amb ) in the direction of distance. In S2, the target detection processing unit 3000 takes the kth plot as the center and confirms that the distance ambiguity (r amb ) to see if there are other plots at positions that are integer multiples of ).

[0125] The processing content of S2 can be Fig.12 In S2, the target detection processing unit 3000 determines the distance ambiguity (r amb ) is there any other plot at the integer multiple of . Fig.12 In the range-velocity map shown in (b), the plots for k=6, 7, and 9 are located at the range ambiguity (r amb ), so the plots are grouped.

[0126] exist Fig.11 The step denoted as S3 in the figure is based on the velocity ambiguity (v amb) in the direction of speed. In S3, the target detection processing unit 3000 takes the kth plot as the center and confirms that in the direction of speed, the speed ambiguity (v amb ) to see if there are other plots at positions that are integer multiples of ).

[0127] S3 processing content can be Fig.12 In S3, the target detection processing unit 3000 takes the k=8th plot as the center and checks whether the velocity ambiguity (v amb ) is there any other plot at the integer multiple of . Fig.12 In the range-velocity map shown in (b), the plots for k = 1, 4, and 16 are located in the velocity ambiguity direction (v amb ), so the plots are grouped.

[0128] exist Fig.11 The step indicated as S4 in FIG. 1 is a step of confirming whether the processing steps S2 and S3 have been performed on all k, that is, all plots.

[0129] If S2 and S3 have not been implemented for all plots, that is, if S4 is "No", the processing step enters S6. In S6, the variable (k) used here is incremented (the operation of adding 1 to the value). After that, the processing step enters S2 after the second round. The processing contents of S2 and S3 after the second round can be Fig.12 In the second round S2 and S3, the object detection processing unit 3000 groups the k=11th plot as the center and the k=3, 5, 10, 11, 12, 13, and 15 plots into one of the other groups.

[0130] When S2 and S3 are performed on all plots, that is, when the answer is YES in S4 , the processing sequence proceeds to S5 .

[0131] exist Fig.11 The step indicated as S5 in FIG. 1 is a step related to the treatment of the plots that are not grouped. In S5 , the object detection processing unit 3000 determines that the plots that do not belong to any group are noise and are false alarms.

[0132] The processing content of S5 can be Fig.12 The distance-speed map shown in (c) will be described. In S5, the object detection processing unit 3000 determines that the plots that do not belong to any group, that is, the plots of k=2 and 14, are noise and false alarms.

[0133] exist Fig.11The step indicated as S7 in FIG. 1 is a step of performing the following processing: for each group, a so-called virtual image plot (also called a ghost) containing blur is excluded, and a so-called real image plot containing no blur is found.

[0134] Typically, the signal intensity associated with the real image plot is stronger than the signal intensity associated with the virtual image plot. Therefore, the real image plot is found from each group considering the information based on the signal intensity.

[0135] The processing content of S7 can be Fig.12 The distance-speed mapping shown in (c) and (d) is used for illustration. Fig.12 In the example shown, the real image plot of the group grouped in the first round of the processing process is the k=8th plot, and the real image plot of the group grouped in the second round of the processing process is the k=11th plot. The k=8th plot and the k=11th plot are plots located at the intersection of the crosses of the cross-shaped grouping. Fig.12 As shown in the example, when the virtual image plot appears in a cross shape with the real image plot as the center, the plot located at the intersection of the cross can be estimated as the real image plot. However, the range ambiguity (r amb ) and velocity ambiguity (v amb ) occurs simultaneously. amb ) and velocity ambiguity (v amb ) occur simultaneously, the virtual image plot appears in a grid pattern in the range-velocity map.

[0136] As described above, the radar device of embodiment 1 has the above-mentioned structure, and therefore can detect the target (Tgt) using radio waves having a plurality of different PRFs, and can achieve target (Tgt) detection that is highly resistant to noise based on a variety of information compared to conventional radar devices.

[0137] Implementation method 2.

[0138] The radar device of Embodiment 2 is a modified example of the radar device of the disclosed technology. In Embodiment 2, the same reference numerals as those used in Embodiment 1 are used except for special descriptions. In Embodiment 2, descriptions overlapping with those in Embodiment 1 are omitted as appropriate.

[0139] Fig.13 2 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 2. More specifically, Fig.13 1 is an explanatory diagram showing the manner in which the pulse impact direction processing unit 720 and the pulse compression unit 730 in the radar device of Embodiment 2 are used. Fig.13 As shown, the radar apparatus according to the second embodiment performs pulse hit direction coherent integration in the pulse hit direction processing section 720 , and performs phase correction type pulse compression in the pulse compression section 730 .

[0140] The radar device of the second embodiment is based on the premise that the speed of the target (Tgt) can be pre-assumed. The pre-assumed speed of the target (Tgt) is a set of speeds (v c ) is given by a formula using the following notation.

[0141]

[0142] Here, the N in the subscript on the right side of formula (6) d is the Doppler bin number (n) that appears in equation (1) d ) is the total number of Doppler bins. In other words, the radar apparatus of Embodiment 2 presupposes the speed of the target (Tgt) in the total number of Doppler bins.

[0143] 《Pulse hitting direction processing unit 720 of implementation mode 2》

[0144] The pulse hitting direction processing unit 720 of the second embodiment uses a speed set (v c ), corrects the phase rotation of the signal caused by the Doppler frequency, and then performs coherent integration in the pulse hitting direction. In addition, the pulse hitting direction processing unit 720 has a case of an LPRF system (720-1) and a case of an HPRF system (720-2), but no matter which system is used, the pulse hitting direction processing unit 720 performs the same processing content.

[0145] The processing performed by the pulse impact direction processing unit 720 of the second embodiment is given by the following formula, for example.

[0146]

[0147] Here, S on the right side of formula (7) j is the signal sent from AD converter 710. The S on the left side of equation (7) f is the processed signal in the pulse hitting direction processing unit 720 (hereinafter referred to as the "coherent integration signal (S f )”). The n that appears in equation (7) h Is from 1 to N h The natural number variable (the pulse hit number), N h is the total number of discrete time signal trains sent from the AD converter 710. t is marked with the subscript n h The part represents the nth h The f on the right side of equation (7) s is the transmission frequency. In the pulse hitting direction processing unit 720 (720-1) in the LPRF system, fs is the f that appears in formula (1) 1 .

[0148] In addition, the pulse hitting direction processing unit 720 performs pulse hitting direction processing on all n az and n el The combination of is used to implement the processing shown in formula (7).

[0149] When there is a missing portion in the data, the pulse hitting direction processing unit 720 of the second embodiment can appropriately fill the missing portion with a predetermined value such as an average value, a median value, or 0.

[0150] The coherent integration signal (S) generated by the pulse hitting direction processing unit 720 of the second embodiment f ) is sent to the pulse compression unit 730.

[0151] 《Pulse compression unit 730 according to embodiment 2》

[0152] The pulse compressor 730 of the second embodiment corrects the frequency shift of the target signal power spectrum due to Doppler and performs pulse compression. The correction of the frequency shift performed by the pulse compressor 730 of the second embodiment is given by the following equation, for example.

[0153]

[0154] The signal (s′) after phase correction is performed in the pulse compressor 730 of the second embodiment f ) is sent to the distance-speed map generating unit 740. The subsequent processing contents are the same as those described in the first embodiment.

[0155] As described above, the radar device of Embodiment 2 has the above-mentioned structure, so it is possible to correct the phase rotation caused by Doppler. By this action, the radar device of Embodiment 2 has an effect of reducing the integral loss in pulse compression in addition to the effect shown in Embodiment 1.

[0156] Implementation method 3.

[0157] The radar device of Embodiment 3 is a modified example of the radar device of the disclosed technology. In Embodiment 3, the same reference numerals as those used in the existing embodiments are used except for special descriptions. In addition, in Embodiment 3, descriptions that overlap with the existing embodiments are appropriately omitted.

[0158] Fig.14 1 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 3. Fig.14As shown, the radar device of the disclosed technology also considers replacing the functions of the pulse hitting direction processing unit 720 and the pulse compression unit 730 with a pulse compression unit 730-F that performs high-speed pulse compression.

[0159] Fig.15 7 is a block diagram showing the detailed functional structure of the pulse compression unit 730-F in the radar device according to the third embodiment. Fig.15 As shown, the pulse compression unit 730-F of embodiment 3 includes a FFT unit 730-F-1 for receiving pulses, a pulse direction CZT unit 730-F-2, a reference pulse generating unit 730-F-3, a FFT unit 730-F-4 for reference pulses, a multiplication unit 730-F-5, and an IFFT processing unit 730-F-6.

[0160] <<FFT unit 730-F-1 for receiving pulses constituting pulse compression unit 730-F>>

[0161] The received pulse FFT unit 730-F-1 constituting the pulse compression unit 730-F is a component for performing FFT in the range direction (hereinafter referred to as "range FFT"). The range FFT performed by the received pulse FFT unit 730-F-1 is given by the following equation.

[0162]

[0163] Here, the transformation of F represented by handwriting with the subscript Range written on it represents the range FFT. j and s in formula (7) j The same as, represents the signal sent from AD converter 710. n in equation (9) h and n in formula (7) h The same is from 1 to N h In addition, the received pulse FFT unit 730-F-1 calculates the natural number of variables (pulse hit number). az and n el The combination of is used to implement the distance FFT shown in equation (9).

[0164] The signal (s) obtained by the received pulse FFT unit 730-F-1 based on the distance FFT fj ) is sent to the pulse direction CZT section 730-F-2.

[0165] 《Pulse direction CZT section 730-F-2 constituting the pulse compression section 730-F》

[0166] The pulse direction CZT unit 730-F-2 constituting the pulse compression unit 730-F is a structural element that performs a chirp-z transform in the pulse hitting direction. The letter CZT included in the name of the pulse direction CZT unit 730-F-2 is derived from the first letter of Chirp Z-Transform, which represents chirp z-transform. Chirp z-transform can perform convolution operations at a high speed.

[0167] The details of the chirp z-transform performed by the pulse direction CZT unit 730 -F- 2 become clear by introducing the following variables (f and g).

[0168]

[0169]

[0170] Here, A appearing in the formula (10) and W appearing in the formula (10) and the formula (11) are given as follows.

[0171]

[0172]

[0173] Here, A given by equation (12) and W given by equation (13) are variables used in the chirp z-transform. Δv appearing in equation (13) c is the set of velocities (v c That is, in the third embodiment, the speed (v c，1 、v c，2 ,…,v c，Nd ) is based on Δv c is an arithmetic progression of differences. f appears in equations (12) and (13) a This is the frequency obtained by adding a frequency that depends on the distance (such as the beat frequency when linear frequency modulation is used) to the transmission frequency. s represents the sampling period, T in equation (13) h Indicates the pulse hit interval.

[0174] The pulse direction CZT section 730-F-2 performs FFT processing on f given by equation (10) and g given by equation (11). The functions F and G obtained by the FFT processing can be expressed as follows.

[0175]

[0176] In equations (14) and (15), F represented by handwriting represents Fourier transform, that is, FFT.

[0177] In the radar device of the second embodiment, the pulse hit number (n) is shown in the equation (7) related to the processing content of the pulse hit direction processing unit 720. h ) and Doppler bin number (n d ). In the radar device of the third embodiment in which the pulse hit direction processing unit 720 is omitted, the pulse hit number (n) is shown in equations (14) and (15) related to Fourier transform. h ) and Doppler bin number (n d ). In the nature of FFT, N d Become with N h Equal values.

[0178] Finally, the pulse direction CZT unit 730-F-2 calculates the value (s′) given by the following formula: f2 ).

[0179]

[0180] The formula (16) of the third embodiment corresponds to the formula (8) of the second embodiment described above (s′ is derived). f 's formula).

[0181] s′ calculated by the pulse direction CZT unit 730-F-2 f2 Sent to multiplication unit 730-F-5.

[0182] 《Reference pulse generating unit 730-F-3 constituting the pulse compression unit 730-F》

[0183] The reference pulse generator 730-F-3 constituting the pulse compressor 730-F generates a reference pulse (s) used in the pulse compression process. s ) structural elements. With reference pulse (s s ) The sampling number associated with n s Indicates. s Take 1 to N s Natural number. Reference pulse (s s ) by the nth s The sampling time (t ns ) is given as a function of its arguments.

[0184] 《FFT unit 730-F-4 for reference pulse constituting pulse compression unit 730-F》

[0185] The reference pulse FFT unit 730-F-4 constituting the pulse compression unit 730-F performs a pulse FFT operation on the reference pulse (s s) Structural elements for implementing FFT.

[0186] Before performing FFT, the reference pulse FFT unit 730 -F- 4 may perform a correction given by the following equation, that is, a correction of the phase rotation due to Doppler.

[0187]

[0188] Where, the radial velocity is (n d -1)Δv c

[0189] Here, T s is the reference pulse (s s ) related sampling period.

[0190] The signal sequence subjected to FFT processing by the reference pulse FFT unit 730 -F- 4 (hereinafter referred to as “FFT output signal sequence”) can be expressed as follows.

[0191]

[0192] The curly brackets used in equation (18) indicate a signal sequence. Here, based on the nature of FFT, N r Become with N s Equal values.

[0193] The FFT output signal sequence generated by the reference pulse FFT unit 730-F-4 is sent to the multiplication unit 730-F-5.

[0194] <<Multiplication unit 730-F-5 constituting pulse compression unit 730-F>>

[0195] The multiplication unit 730-F-5 constituting the pulse compression unit 730-F converts the signal (s′) from the pulse direction CZT unit 730-F-2 into f2 ) and the signal (s′) from the reference pulse FFT unit 730-F-4 sf Specifically, the multiplication unit 730-F-5 implements the multiplication processing shown below.

[0196] s sf2 (n r , n d ) = s′ f2 (n r , n d )[s′ sf (n r )] * ...(19)

[0197] Here, the superscript asterisk appearing on the right side of equation (19) indicates complex conjugation.

[0198] <IFFT processing unit 730-F-6 constituting the pulse compression unit 730-F>

[0199] The IFFT processing unit 730-F-6 constituting the pulse compression unit 730-F is a component that performs inverse Fourier transform. The IFFT in the name of the IFFT processing unit 730-F-6 comes from Invers, which stands for inverse fast Fourier transform. e The first character of FastFourier Transform.

[0200] In the radar apparatus according to the third embodiment, the processing in the subsequent stage of the pulse compression unit 730 -F is the same as the processing in the radar apparatus according to the conventional embodiment.

[0201] As described above, the radar device of the third embodiment has the above-mentioned structure, and therefore can perform CZT processing. By this action, the radar device of the third embodiment can perform convolution operation at high speed and correct the phase rotation caused by Doppler in addition to the effect shown in the first embodiment.

[0202] Implementation method 4.

[0203] The radar device of Embodiment 4 is a modified example of the radar device of the disclosed technology. In Embodiment 4, the same reference numerals as those used in the existing embodiments are used except for special descriptions. In Embodiment 4, descriptions that overlap with those in the existing embodiments are appropriately omitted.

[0204] Fig.16 1 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 4. Fig.16 As shown in the upper layer of FIG. 7 , the signal processing system 700 of the disclosed technology can also implement signal processing using a filter bank. A filter bank is an array of bandpass filters, which is a circuit that divides an input signal into multiple components. Fig.16 As shown in the lower layer of the present disclosure, the target detection processing unit 3000 of the disclosed technology can also be composed of N f Independent target detection processing units 3000 (3000-#1, 3000-#2, ..., 3000-#N f ) f is the total number of bandpass filters in the filter bank. f (n f is 1, 2, ..., N f When the identification number of the bandpass filter in the filter bank is set as a natural number, no matter which signal processing system 700 in the LPRF system and the HPRF system passes through the nth fThe signal components of each bandpass filter are sent to the corresponding target detection processing unit 3000-#n f .

[0205] Fig.17 2 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 4. Fig.17 As shown, the filter bank included in the signal processing system 700 can be implemented by, for example, the integral processing unit 760 in the signal processing system 700 .

[0206] 《Integral Processing Unit 760 of Implementation Method 4》

[0207] As described in the first embodiment, the distance-speed map (M) generated by the LPRF system is sent to the integration processing unit 760 of the fourth embodiment. rd1 ) and the range-velocity map (M) generated by the HPRF system rd2 ). Distance-speed mapping (M rd1 ) and distance-speed mapping (M rd2 ) is decomposed into components by the filter group possessed by the integral processing unit 760.

[0208] The integration processing unit 760 of the fourth embodiment performs coherent integration after matching the phases of the two range-velocity maps in each component. Generally, it is not easy to know the phase difference between the two range-velocity maps. Therefore, specifically, the integration processing unit 760 of the fourth embodiment performs the processing given by the following equation.

[0209]

[0210] As shown in equation (20), the radar device of embodiment 4 is prepared in advance by N f The filter bank consists of a bandpass filter, for the distance velocity mapping (M rd1 ) and distance-speed mapping (M rd2 ) is used to map the distance velocity of either side using 2π / N f After phase correction is performed on the integer multiple of , coherent integration is performed. In this specification, M on the left side of equation (20) rd It is called the coherent integration signal (M rd ).

[0211] The integration processing unit 760 of the fourth embodiment may also calculate the power of the coherent integration signal (M) based on the relationship that the square of the signal amplitude represents the power. rd ) to calculate p rd The p performed by the integration processing unit 760 rd The calculation of is conceptually given by the following formula.

[0212] p rd =|Mrd | 2 ...(twenty one)

[0213] The formula (21) of the fourth embodiment corresponds to the formula (3) of the first embodiment.

[0214] The object detection processing unit 3000 (3000-#1, 3000-#2, ..., 3000-#N) of the fourth embodiment f )》

[0215] The object detection processing unit 3000 (3000-#1, 3000-#2, ..., 3000-#N) of the fourth embodiment f ) The signal that has been coherently integrated with minimal loss in the filter group is set as a target signal related to the target (Tgt) to detect the target (Tgt).

[0216] As described above, the radar device according to the fourth embodiment has the above-mentioned configuration, and therefore can generate a range-speed map (M rd1 ) and the range-velocity map (M) generated by the HPRF system rd2 ) performs coherent integration. Through this action, the radar device of the fourth embodiment has an effect of improving the SN ratio in addition to the effect shown in the first embodiment.

[0217] Implementation method 5.

[0218] The radar device of Embodiment 5 is a modified example of the radar device of the disclosed technology. In Embodiment 5, the same reference numerals as those used in the existing embodiments are used except for special descriptions. In addition, in Embodiment 5, descriptions that overlap with the existing embodiments are appropriately omitted.

[0219] The radar apparatus according to the fifth embodiment assumes that the LPRF transmitter 110 and the HPRF transmitter 210 perform transmission over a plurality of CPIs (Coherent Processing Intervals).

[0220] Fig.18 FIG. 5 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 5. Fig.18 As shown, the radar device of the disclosed technology can also implement and use signal processing using maximum ratio combining.

[0221] Fig.19 7 is a block diagram showing a detailed functional structure of the integral processing unit 760 in the radar device according to the fifth embodiment. Fig.19As shown, signal processing using maximum ratio synthesis can also be realized by including a memory circuit and a maximum ratio synthesis unit in the integral processing unit 760. In addition, the maximum ratio synthesis unit can include a correlation matrix generation unit, a weight calculation unit, an addition processing unit, and a CPI direction PDI.

[0222] Fig. 20 This is an explanatory diagram showing a time series of a situation in which the radar apparatus according to the fifth embodiment performs transmission and reception over a plurality of CPIs. Fig. 20 The "CPI number N cpi "N" cpi It is the total number of CPI.

[0223] 《Integral Processing Unit 760 of Implementation Method 5》

[0224] The memory circuit included in the integration processing unit 760 of the fifth embodiment is a component that stores a signal as a signal transmitted in units of CPI.

[0225] The correlation matrix generating unit included in the integral processing unit 760 of the fifth embodiment is a component that generates a correlation matrix of the transmitted signal.

[0226] The weight calculation unit included in the integral processing unit 760 of the fifth embodiment is a component that outputs an eigenvector corresponding to the maximum eigenvalue of the correlation matrix as a weight.

[0227] The addition processing unit included in the integration processing unit 760 of the fifth embodiment is a component that performs addition processing using weights.

[0228] The CPI direction PDI included in the integration processing unit 760 of the fifth embodiment is a component that performs incoherent integration in the CPI direction.

[0229] As described above, the radar apparatus of the fifth embodiment assumes that the LPRF transmitter 110 and the HPRF transmitter 210 transmit across a plurality of CPIs (hereinafter, this assumption is referred to as "precondition unique to the fifth embodiment"). That is, in the interpolation processing unit 750 of the signal processing system 700 of the fifth embodiment, the range-speed map is transmitted from both the range-speed map generating unit 740-1 of the LPRF system and the range-speed map generating unit 740-2 of the HPRF system in units of CPI. As described above, the range-speed map is, for example, as shown in equation (3), n r 、n d 、n az and n el In the signal processing system 700 of the fifth embodiment, since there are unique premises in the fifth embodiment, in addition to these four parameters, the distance-speed mapping also needs to include a number (hereinafter referred to as "CPI number") for identifying which CPI it is.cpi )" or just "n cpi ”) are further added as parameters.

[0230] Therefore, in consideration of easy viewing, this specification omits n in the parameters when expressing the distance-speed mapping of the fifth embodiment. r 、n d 、n az and n el , only records n cpi .

[0231] As described above, the correlation matrix generator included in the integral processing unit 760 of Embodiment 5 generates a correlation matrix of the transmitted signal. Specifically, the correlation matrix generator included in the integral processing unit 760 generates a correlation matrix (R) given by the following equation.

[0232] R: =A H A

[0233] in

[0234]

[0235] Here, the superscript H in the matrix A shown in equation (22) represents the Hermitian transposition. cpi and appear in Fig. 20 N cpi Similarly, is the total number of CPI. That is, n cpi Take 1 to N cpi The row size of the matrix A shown in formula (22) is N cpi .

[0236] As described above, the weight calculation unit included in the integral processing unit 760 of the fifth embodiment calculates the maximum eigenvalue (λ) of the correlation matrix (R). max ) corresponding to the eigenvector (w max ) to calculate the weight coefficient. The maximum eigenvalue (λ) of the correlation matrix (R) max ) and the eigenvector (w max ) have the following relationship.

[0237]

[0238] The lower layer of formula (23) is the eigenvector (w max ) is displayed as a component, and the eigenvector (w max ) component (w max , 1 and w max，2 ) is used as the weight coefficient.

[0239] As described above, the addition processing unit included in the integration processing unit 760 of Embodiment 5 performs weighted addition processing. Specifically, the weighted addition processing performed by the addition processing unit is given by the following equation.

[0240] M rd (n cpi ):=w max，1 M rd1 (n cpi )+w max，2 M rd2 (n cpi )...(twenty four)

[0241] Formula (24) is based on the maximum eigenvalue (λ max ) corresponding to the eigenvector (w max ) is weighted by adding the weighted sum to achieve maximum ratio synthesis. The formula (24) of the fifth embodiment corresponds to the formula (20) of the fourth embodiment.

[0242] As described above, the integral processing unit 760 of the fifth embodiment has a CPI direction PDI for the processing result (M) of the addition processing unit. rd ) performs incoherent integration in the CPI direction. Specifically, the incoherent integration in the CPI direction implemented by the CPI direction PDI is given by the following formula.

[0243]

[0244] The formula (25) of the fifth embodiment corresponds to the formula (3) of the first embodiment and the formula (21) of the fourth embodiment.

[0245] As described above, the radar device according to the fifth embodiment has the above-mentioned configuration, and therefore can generate a range-speed map (M rd1 ) and the range-velocity map (M) generated by the HPRF system rd2 ) performs maximum ratio synthesis. Through this action, the radar device of the fifth embodiment has the effect of improving the SN ratio in addition to the effect shown in the first embodiment.

[0246] Implementation method 6.

[0247] The radar device of Embodiment 6 is a modified example of the radar device of the disclosed technology. In Embodiment 6, the same reference numerals as those used in the existing embodiments are used except for special descriptions. In addition, in Embodiment 6, descriptions that overlap with the existing embodiments are appropriately omitted.

[0248] Embodiments 1 to 5 assume that blur (more precisely, a virtual image including blur) appears at a theoretically determined position. The radar device of Embodiment 6 assumes that the actually measured plot position in the range-velocity map is slightly offset from the theoretically determined position.

[0249] Fig.21 1 is an explanatory diagram showing the manner of some functional blocks in the radar device of Embodiment 6. Fig.21 As shown, in the radar device of the disclosed technology, the target detection processing unit 3000 can also be implemented by a range type target determination processing unit composed of a correspondence detection processing unit and a range setting type 2 in 1 detection processing unit.

[0250] "Object detection processing unit 3000 of implementation method 6"

[0251] The range setting type 2-in-1 detection processing unit of the target detection processing unit 3000 of the sixth embodiment is a structural element that performs 2-in-1 detection processing after setting the signal near the position where the ambiguity occurs as the range of the ambiguity of the target signal related to the target (Tgt). The position referred to as "near the position where the ambiguity occurs" is determined by the following Fig. 22 The description becomes clear.

[0252] Fig. 22 This is a range-speed map for explaining the case where the radar device of Embodiment 6 sets the ambiguity range. Fig. 22 In the illustrated range-speed map, the central circle labeled "target signal" shows a real image of the target signal related to the target (Tgt) without any ambiguity. Fig. 22 In the illustrated distance-speed map, other circles plotted at positions other than the center indicate virtual images of target signals related to the target (Tgt) including blur. The dotted circle outside the circle indicating the virtual image of the target signal related to the target (Tgt) indicates the area in which the target detection processing unit 3000 of the sixth embodiment performs range setting.

[0253] in addition, Fig. 22 This is an example of a distance-speed map when there is one target (Tgt).

[0254] The radar device according to the sixth embodiment determines that the plot appearing in the area whose range is set by the target detection processing unit 3000 is a virtual image related to the target (Tgt).

[0255] As described above, the radar device of Embodiment 6 has the above-mentioned structure, so even if a virtual image related to the target (Tgt) appears slightly offset from the theoretically calculated position, it can be processed as information related to the target (Tgt).

[0256] In addition, the radar device of the disclosed technology is not limited to the forms illustrated in the respective embodiments, and the respective embodiments can be combined, arbitrary components of the respective embodiments can be modified, or arbitrary components can be omitted in the respective embodiments.

[0257] Industrial Applicability

[0258] The radar device of the disclosed technology can be applied to the technical field of measuring the position and speed of a target to be observed, and therefore has industrial applicability.

[0259] Description of Reference Numerals

[0260] 100LPRF radar transmission system, 110LPRF transmitter, 120LPRF transmission antenna, 200HPRF radar transmission system, 210HPRF transmitter, 220HPRF transmission antenna, 600 receiving system, 610 element antenna, 620 beam forming unit, 630 band pass filter, 640 receiver, 650 mixing unit, 700 signal processing system, 710AD converter, 720 pulse hitting direction processing unit, 730 pulse compression unit, 73 0-F-1 FFT unit for receiving pulse, 730-F-2 pulse direction CZT unit, 730-F-3 reference pulse generating unit, 730-F-4 FFT unit for reference pulse, 730-F-5 multiplication unit, 730-F-6 IFFT processing unit, 740 distance-speed mapping generating unit, 750 interpolation processing unit, 760 integration processing unit, 770 comparison processing unit, 1000LPRF radar device, 2000HPRF radar device, 3000 target detection processing unit.

Claims

1. A radar device, wherein: The radar device comprises: an LPRF radar device that irradiates LPRF radio waves toward the atmosphere and receives reflected waves reflected by a target; and The HPRF radar device irradiates HPRF radio waves toward the atmosphere and receives the reflected waves reflected by the target. The LPRF radar device and the HPRF radar device include a signal processing system having an LPRF system and an HPRF system, respectively. The radar device further includes a target detection processing unit that detects the position and speed of the target based on the information sent from the signal processing system included in the LPRF radar device and the information sent from the signal processing system included in the HPRF radar device.

2. The radar device according to claim 1, wherein: The LPRF radar device also has: An LPRF radar transmission system, comprising an LPRF transmitter and an LPRF transmission antenna; and a receiving system including a bandpass filter composed of bandpass filters for a frequency band of an LPRF pulse and a frequency band of an HPRF pulse, respectively; The signal processing system processes the signal transmitted from the receiving system.

3. The radar device according to claim 1, wherein: The HPRF radar device also has: A HPRF radar transmission system comprising a HPRF transmitter and an HPRF transmission antenna; and a receiving system including a bandpass filter composed of bandpass filters for a frequency band of an LPRF pulse and a frequency band of an HPRF pulse, respectively; The signal processing system processes the signal transmitted from the receiving system.

4. The radar device according to claim 1, wherein: The signal processing systems of the LPRF radar device and the HPRF radar device respectively include: a distance-speed map generating unit, which generates a distance-speed map; an interpolation processing unit that interpolates and corrects the range bins and Doppler bins in the range-velocity map by taking into account the information obtained by the LPRF system and the information obtained by the HPRF system; An integration processing unit that performs integration processing; as well as The comparison processing unit compares the component of the signal processed by the integration processing unit with a preset threshold value.

5. The radar device according to claim 1, wherein: The target detection processing unit compares the information of the structure sent from the signal processing system in the LPRF radar device with the information of the structure sent from the signal processing system in the HPRF radar device, and confirms in which record a certain same target among the targets appears in each structure, The target detection processing unit performs processing so that a result detected by only one of the LPRF radar device and the HPRF radar device can be output as a detection result.

6. The radar device according to claim 4, wherein: The integration processing performed by the integration processing unit is post-detection integration.

7. The radar device according to claim 4, wherein: The signal processing system further comprises: A pulse hitting direction processing unit, which uses a previously assumed speed set of the target to correct the phase rotation of the signal caused by the Doppler frequency, and then performs coherent integration in the pulse hitting direction; as well as The pulse compression unit corrects the frequency shift of the power spectrum of the target signal caused by Doppler and performs pulse compression.

8. The radar device according to claim 4, wherein: The signal processing system comprises: A FFT unit for receiving pulses, which performs FFT in the range direction; A pulse direction CZT section, which performs a chirp z-transformation of the pulse hitting direction; a reference pulse generating unit for generating a reference pulse used in a pulse compression process; a reference pulse FFT unit that performs FFT on the reference pulse; a multiplication unit that multiplies the signal from the pulse direction CZT unit and the signal from the reference pulse FFT unit; and The IFFT processing unit performs inverse Fourier transform.

9. The radar device according to claim 4, wherein: The integration processing unit has a filter group consisting of a plurality of bandpass filters. The target detection processing unit performs target detection processing on the signal components that have passed through the respective bandpass filters.

10. The radar device according to claim 4, wherein: The integral processing unit comprises: A correlation matrix generating unit, which generates a correlation matrix of a signal transmitted in units of CPI; a weight calculation unit that outputs an eigenvector corresponding to the maximum eigenvalue of the correlation matrix as a weight; an addition processing unit that performs addition processing using the weight; and CPI direction PDI, which performs incoherent integration in the CPI direction.

11. The radar device according to claim 5, wherein: The target detection processing unit also sets a signal located near a position where blur occurs as a range of the blur of the target signal related to the target.

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