Radar device

Abstract

The radar device includes a vehicle speed acquisition unit that acquires a speed of a vehicle, a transmission unit that transmits a transmission signal to a region including a direction orthogonal to a traveling direction of the vehicle, a reception unit that receives a reflection signal of the transmission signal transmitted by the transmission unit, a pseudo signal generation unit that generates a number of pseudo reception signals corresponding to the speed of the vehicle acquired by the vehicle speed acquisition unit based on the reflection signal received by the reception unit, and a distance detection unit that detects a distance to an object present in the direction orthogonal to the traveling direction of the vehicle based on the reflection signal received by the reception unit and the pseudo reception signals generated by the pseudo signal generation unit.

Description

Technical Field

[0001] This invention relates to radar devices. Background Technology

[0002] Patent Document 1 discloses a radar device that detects the distance of an object by illuminating it with light within a search range and receiving the reflected light from the object. The device also discloses a technique for reducing the number of times light is received and emitted when the vehicle is performing a specific task, with the aim of reducing power consumption.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-25449 Summary of the Invention

[0006] -The problem the invention aims to solve-

[0007] However, in the technology described in Patent Document 1, the accuracy of detecting the distance to the object may be reduced due to the reduction in the number of times light is received and emitted.

[0008] -Methods for solving problems-

[0009] One embodiment of the radar apparatus includes: a vehicle speed acquisition unit for acquiring the speed of a vehicle; a transmission unit for transmitting a transmission signal to a region including a direction orthogonal to the vehicle's direction of travel; a receiving unit for receiving a reflected signal of the transmission signal transmitted by the transmission unit; a spurious signal generation unit for generating a number of spurious received signals corresponding to the vehicle speed acquired by the vehicle speed acquisition unit based on the reflected signals received by the receiving unit; and a distance detection unit for detecting the distance of an object existing in a direction orthogonal to the vehicle's direction of travel based on the reflected signals received by the receiving unit and the spurious received signals generated by the spurious signal generation unit.

[0010] -Invention Effects-

[0011] According to one embodiment of the radar device, a radar device is provided that can detect the distance of objects around a vehicle with high accuracy and suppress power consumption related to signal transmission and reception. Attached Figure Description

[0012] Figure 1 This is a system structure diagram of a radar device according to one implementation method.

[0013] Figure 2 This is a diagram showing the structure of a radar range detection unit included in a radar device according to one embodiment.

[0014] Figure 3 This is a flowchart illustrating an example of the processing steps of a radar device according to one embodiment.

[0015] Figure 4 This is a flowchart illustrating an example of the range detection processing steps performed by a radar range detection unit included in a radar device according to one embodiment.

[0016] Figure 5 This is a graph showing the relationship between transmission time and frame period used for calculating the reference transmission pulse count.

[0017] Figure 6 This is a graph showing the relationship between the reference transmission pulse number N and the transmission pulse number M in a detection cycle.

[0018] Figure 7A This diagram illustrates an example of signals transmitted and received by a radar device according to one embodiment.

[0019] Figure 7B This diagram illustrates an example of signals transmitted and received by a radar device according to one embodiment.

[0020] Figure 7C This diagram illustrates an example of signals transmitted and received by a radar device according to one embodiment.

[0021] Figure 8 This is a diagram illustrating an example of generating a parking space image of a radar device according to one embodiment.

[0022] Figure 9 This is a diagram illustrating an example of a parking space image generated by a radar device according to one embodiment. Detailed Implementation

[0023] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

[0024] (System structure of radar device 100)

[0025] Figure 1 This is a system structure diagram of a radar device 100 according to one embodiment. For example... Figure 1 As shown, the radar device 100 includes a radar distance detection unit 101, a camera distance detection unit 102, a vehicle speed / coordinate detection unit 103, a memory 104, a radar obstacle map generation unit 105, a camera obstacle map generation unit 106, a parking space detection unit 107, a parking space image generation unit 108, and a display 109.

[0026] The radar distance detection unit 101 uses radar waves to detect the distance to objects existing to the side of the vehicle (an example of a direction orthogonal to the vehicle's direction of travel).

[0027] The camera distance detection unit 102 uses a camera to capture an image of the side of the vehicle and performs image recognition processing on the image to detect the distance of objects existing on the side of the vehicle.

[0028] The vehicle speed / coordinate detection unit 103 acquires the vehicle's speed and coordinates. For example, the vehicle speed / coordinate detection unit 103 acquires the vehicle's speed and coordinates from various sensors or ECUs mounted on the vehicle. That is, the vehicle speed / coordinate detection unit 103 functions as a "vehicle speed acquisition unit".

[0029] The memory 104 stores the distance to the object detected by the radar distance detection unit 101, the distance to the object detected by the camera distance detection unit 102, and the speed and coordinates of the vehicle detected by the vehicle speed / coordinate detection unit 103.

[0030] The radar obstacle map generation unit 105 generates a radar obstacle map based on multiple distances (distances to objects) detected by the radar distance detection unit 101. The radar obstacle map represents the presence or absence of objects (obstacles) in the area surrounding the vehicle, centered on the vehicle, as detected by the radar distance detection unit 101, in a two-dimensional matrix.

[0031] The camera obstacle map generation unit 106 generates a camera obstacle map based on multiple distances (distances to objects) detected by the camera distance detection unit 102. The camera obstacle map represents the presence or absence of objects (obstacles) in the area surrounding the vehicle, centered on the vehicle, as detected by the camera distance detection unit 102, in a two-dimensional matrix.

[0032] The parking space detection unit 107 detects parking spaces around the vehicle based on a radar obstacle map generated by the radar obstacle map generation unit 105 and a camera obstacle map generated by the camera obstacle map generation unit 106. For example, based on the radar obstacle map and the camera obstacle map, the parking space detection unit 107 detects spaces around the vehicle that are rectangular boxes containing non-existent objects (obstacles) of sufficient size to allow the vehicle to park as parking spaces.

[0033] The parking space image generation unit 108 generates an image of the parking space detected by the parking space detection unit 107. For example, the parking space image generation unit 108 generates a two-dimensional image representing the area surrounding the vehicle centered on the vehicle. In this two-dimensional image, the parking space is emphasized using a given emphasis display method (e.g., displaying a rectangle, etc.), thereby generating an image of the parking space.

[0034] The display 109 displays an image of the parking space generated by the parking space image generation unit 108.

[0035] (Structure of radar range detection unit 101)

[0036] Figure 2 This is a diagram showing the structure of the radar range detection unit 101 included in a radar device 100 according to one embodiment.

[0037] like Figure 2 As shown, the radar range detection unit 101 includes a transmitting unit 210, a receiving unit 220, and a signal processing unit 230.

[0038] The transmitting unit 210 transmits a transmission signal (radar wave) toward the side of the vehicle. In particular, the transmitting unit 210 transmits a transmission signal comprising M transmission pulses in each detection cycle. Here, M is the number of transmission pulses calculated by the transmission pulse parameter calculation unit 231 (i.e., the number of transmission pulses less than the reference number of transmission pulses N that satisfies a given distance detection accuracy).

[0039] Specifically, the transmitting unit 210 includes a controller 211, a modulator 212, an oscillator 213, an amplifier 214, and a transmitting antenna 215. The controller 211 generates a transmission code. The modulator 212 generates a modulated signal by frequency modulating the transmission code generated by the controller 211. The oscillator 213 generates a transmission signal (e.g., a radar wave such as an FMCW wave) with an oscillation frequency corresponding to the modulated signal generated by the modulator 212. The amplifier 214 amplifies the signal level of the transmission signal generated by the oscillator 213. The transmitting antenna 215 radiates the amplified transmission signal into space.

[0040] Whenever the transmitting unit 210 transmits a transmission signal, the receiving unit 220 receives the reflected signal of the transmission signal transmitted by the transmitting unit 210. That is, the receiving unit 220 receives the reflected signal consisting of M receiving pulses in the case where the transmitting unit 210 transmits a transmission signal consisting of M transmission pulses.

[0041] Specifically, the receiving unit 220 includes a receiving antenna 221, an amplifier 222, a mixer 223, and an analog-to-digital converter (A / D) 224. The receiving antenna 221 receives reflected signals from space. The amplifier 222 amplifies the reflected signals received by the receiving antenna 221. The mixer 223 performs phase detection by mixing the transmitted signal and the reflected signal to generate an intermediate frequency (IF) signal. The A / D converter 224 is an A / D converter that converts the IF signal generated by the mixer 223 from an analog signal to a digital signal. The receiving unit 220 outputs the IF signal (digital signal) from the A / D converter 224 to the signal processing unit 230.

[0042] Alternatively, the transmitting unit 210 and the receiving unit 220 may be implemented, for example, by a radar transmitter / receiver 100A installed in the vehicle such that the side of the vehicle is the direction of signal transmission and reception.

[0043] The signal processing unit 230 includes a transmission pulse parameter calculation unit 231, a supplementary parameter calculation unit 232, a FET unit 233, a pseudo signal generation unit 234, and a distance detection unit 235.

[0044] The transmission pulse parameter calculation unit 231 calculates the reference transmission pulse number N and the transmission pulse number M as transmission pulse parameters. The reference transmission pulse number N is the number of transmission pulses required to meet the given distance detection accuracy (the number of transmission pulses per detection cycle). The lower the vehicle speed obtained by the vehicle speed / coordinate detection unit 103, the larger the reference transmission pulse number N is set by the transmission pulse parameter calculation unit 231. This is because the lower the vehicle speed, the smaller the relative speed between the vehicle and the object, thus requiring higher resolution. The transmission pulse number M is the actual number of transmission pulses transmitted by the transmission unit 210 (the number of transmission pulses per detection cycle).

[0045] The supplementary parameter calculation unit 232 calculates the number of pseudo-received signals K and uses the number of pulses I as a supplementary parameter. The number of pseudo-received signals K is the number of pseudo-received signals required to meet a given distance detection accuracy. That is, the number of pseudo-received signals K is obtained by subtracting the number of transmitted pulses M from the reference transmitted pulse number N. The number of pulses I is the number of received pulses out of M received pulses used for generating pseudo-received signals.

[0046] The FET unit 233 generates distance data (frequency spectrum) representing the distance to an object by performing a Fourier transform on the reflected signal received by the receiving unit 220 (specifically, the intermediate frequency signal output from the receiving unit 220). The transmitting unit 210 of the FET unit 233 continuously transmits a transmission signal including M transmission pulses multiple times, and the receiving unit 220 continuously generates multiple distance data based on continuously receiving a reflected signal including M reception pulses multiple times.

[0047] The pseudo signal generation unit 234 generates a pseudo signal based on the reflected signal including multiple received pulses received by the receiving unit 220, which is calculated by the supplementary parameter calculation unit 232 as the pseudo received signal number K (that is, the number corresponding to the vehicle speed obtained by the vehicle speed / coordinate detection unit 103).

[0048] In particular, the pseudo signal generation unit 234 generates K pseudo received signals for each detection cycle, where K is the difference between the reference transmission pulse number N corresponding to the vehicle speed obtained by the vehicle speed / coordinate detection unit 103 and the transmission pulse number M of the transmission signal of the transmission unit 210.

[0049] Furthermore, the pseudo signal generation unit 234 generates K pseudo received signals based on the reflected signals including M pulses received by the receiving unit 220 using statistical calculations.

[0050] The distance detection unit 235 detects the distance to an object located to the side of the vehicle based on the reflected signals of M received pulses received by the receiving unit 220 and the K pseudo received signals generated by the pseudo signal generation unit 234. Specifically, the distance detection unit 235 detects the distance to an object located to the side of the vehicle by performing coherent integration on the M received pulses and the K pseudo received signals.

[0051] (An example of the processing steps of radar device 100)

[0052] Figure 3 This is a flowchart illustrating an example of the processing steps of a radar device 100 according to one embodiment.

[0053] First, the vehicle speed / coordinate detection unit 103 begins to acquire the vehicle's speed and coordinates (step S301). For example, the vehicle speed / coordinate detection unit 103 acquires the vehicle's speed and coordinates using a vehicle speed sensor, a position sensor, etc., at each given sampling period (e.g., every 1 second, every 0.5 seconds, etc.).

[0054] Next, the radar device 100 executes steps S302 to S304 and steps S305 to S307 in parallel.

[0055] <Steps S302~S304>

[0056] In step S302, the camera distance detection unit 102 uses a camera to detect the distance to an object present on the side of the vehicle. For example, the camera distance detection unit 102 uses a camera positioned to the side of the vehicle and detects the distance to an object present on the side of the vehicle at given sampling intervals (e.g., every 1 second, every 0.5 seconds, etc.).

[0057] Next, the radar device 100 determines whether a given distance has been traveled based on the coordinates obtained by the vehicle speed / coordinate detection unit 103 (step S303).

[0058] In step S303, if it is determined that the given distance has not been traveled (step S303: No), the radar device 100 executes step S302 again.

[0059] On the other hand, in step S303, if it is determined that a given distance has been traveled (step S303: Yes), the camera obstacle map generation unit 106 generates a camera obstacle map based on multiple distances detected by the camera distance detection unit 102 (step S304).

[0060] <Steps S305~S307>

[0061] In step S305, the radar distance detection unit 101 uses radar waves to detect the distance of objects existing to the side of the vehicle. For example, the radar distance detection unit 101 uses a radar transmitter and receiver 100A (i.e., transmitter 210 and receiver 220) disposed to the side of the vehicle to detect the distance of objects existing to the side of the vehicle at given sampling periods (e.g., every 1 second, every 0.5 seconds, etc.).

[0062] Next, the radar device 100 determines whether a given distance has been traveled based on the coordinates obtained by the vehicle speed / coordinate detection unit 103 (step S306).

[0063] In step S306, if it is determined that the given distance has not been traveled (step S306: No), the radar device 100 executes step S305 again.

[0064] On the other hand, in step S306, if it is determined that a given distance has been traveled (step S306: Yes), the radar obstacle map generation unit 105 generates a radar obstacle map based on multiple distances detected by the radar distance detection unit 101 (step S307).

[0065] <Step S308~>

[0066] If a camera obstacle map is generated in step S304 and a radar obstacle map is generated in step S307, the parking space detection unit 107 detects the parking space around the vehicle based on the radar obstacle map and the camera obstacle map (step S308).

[0067] Next, the parking space image generation unit 108 generates an image of the parking space detected in step S308 (step S309).

[0068] Then, the display 109 shows the image of the parking space generated in step S309 (step S310), and the radar device 100 ends. Figure 3 The series of processes shown.

[0069] (An example of the range detection processing steps performed by the radar range detection unit 101)

[0070] Figure 4 This is a flowchart illustrating an example of the distance detection processing steps of the radar distance detection unit 101 included in a radar device 100 according to one embodiment. Figure 4 Detailed Figure 3An example of the distance detection processing (step S305) of the radar distance detection unit 101 shown.

[0071] First, the radar range detection unit 101 determines whether it is the first execution (step S401).

[0072] In step S401, if it is determined that this is the first execution (step S401: Yes), the radar range detection unit 101 sets given initial values ​​for the number of transmitted pulses M, the number of pseudo-received signals K, and the number of utilized pulses I (step S402). Then, the radar range detection unit 101 causes the processing to proceed to step S409.

[0073] On the other hand, in step S401, if it is determined that this is not the first execution (step S401: no), the radar distance detection unit 101 determines whether the change in vehicle speed is above a given threshold A (step S403).

[0074] In step S403, if it is determined that the change in vehicle speed is not above the given threshold A (step S403: No), the radar distance detection unit 101 causes the processing to proceed to step S409.

[0075] On the other hand, in step S403, if it is determined that the change in vehicle speed is above a given threshold A (step S403: Yes), the pulse parameter calculation unit 231 calculates the reference pulse number N, Nmin (step S404).

[0076] Then, the radar range detection unit 101 determines whether N / Nmin is above the given threshold B (step S405).

[0077] In step S405, if it is determined that N / Nmin is greater than or equal to the given threshold B (step S405: Yes), the transmit pulse parameter calculation unit 231 sets N / B for the transmit pulse number M, and the supplementary parameter calculation unit 232 sets M for the pulse number I (step S407). Then, the supplementary parameter calculation unit 232 calculates the number of pseudo-received signals K = NM (step S408), and the radar range detection unit 101 causes the processing to proceed to step S409.

[0078] On the other hand, in step S405, if it is determined that N / Nmin is not above the given threshold B (step S405: No), the transmission pulse parameter calculation unit 231 sets Nmin for the number of transmission pulses M, and the supplementary parameter calculation unit 232 sets M for the number of pulses I (step S406). Then, the supplementary parameter calculation unit 232 calculates the number of pseudo-received signals K = NM (step S408), and the radar range detection unit 101 causes the processing to proceed to step S409.

[0079] In step S409, the transmitting unit 210 transmits a transmission signal comprising M transmission pulses to the side of the vehicle, and the receiving unit 220 receives a reflected signal comprising M reception pulses. Here, M is the number of transmission pulses set in step S402, step S406, or step S407.

[0080] Next, the FET unit 233 performs a Fourier transform on the intermediate frequency signal generated based on the reflected signal including the M received pulses received in step S409, thereby generating M distance data representing the distance to the object (step S410).

[0081] Next, the pseudo-signal generation unit 234 generates K pseudo-received signals based on the M received pulses received in step S409 and the distance data obtained from the distance data generated in step S410 based on the I received pulses (step S411). The pseudo-received signals are pseudo-distance data obtained from the distance data generated from the I received pulses. Here, K is the number of pseudo-received signals set in step S402 or step S408. Furthermore, I is the number of pulses used set in step S402, step S406, or step S407.

[0082] Next, the distance detection unit 235 performs coherent integration on the M distance data generated in step S410 and the K pseudo-received signals generated in step S411, thereby detecting the distance of objects existing to the side of the vehicle (step S412).

[0083] The distance detection unit 235 can detect the spectral intensity with a frequency of zero in the result obtained by FET conversion as the distance to an object with a relative speed of 0 relative to the vehicle by performing coherent integration.

[0084] After that, the radar range detection unit 101 ended. Figure 4 The series of processes shown.

[0085] (Example of calculating the reference number of transmitted pulses N)

[0086] Reference Figure 5 The calculation example of the reference number of transmitted pulses N of the transmitted pulse parameter calculation unit 231 will be explained. Figure 5 This is a graph showing the relationship between the transmission time Tsweep and the frame period Tframe, used to calculate the reference transmission pulse number N.

[0087] First, the pulse parameter calculation unit 231 calculates the transmission time Tsweep for each pulse using the following mathematical formula (1). Here, Vmax is the maximum vehicle speed used in parking space detection, and λ is the wavelength of the radar wave transmitted from the transmission unit of the radar range detection unit 101.

[0088] Tsweep=4(Vmax×λ)…(1)

[0089] Next, the pulse parameter calculation unit 231 calculates the frame period Tframe that satisfies the distance accuracy based on the current vehicle speed V using the following mathematical formula (2). Here, Xacc is the distance accuracy in the X-axis direction (the direction corresponding to the left-right direction of the vehicle).

[0090] Tframe=Xacc / V…(2)

[0091] Next, the pulse parameter calculation unit 231 calculates the reference number of transmitted pulses N using the following mathematical formula (3).

[0092] N = Tframe / Tsweep…(3)

[0093] Additionally, distance accuracy Xacc is a design consideration; for example, it is set to "10cm" (however, it is not limited to this). Furthermore, maximum vehicle speed Vmax is a design consideration; for example, it is set to "30km / h" (however, it is not limited to this).

[0094] (Example of the calculation of pseudo-received signal number K and pulse number I)

[0095] Reference Figure 6 The calculation examples of the pseudo received signal number K calculated by the supplementary parameter calculation unit 232 and the calculation of the pulse number I will be explained. Figure 6 This is a graph showing the relationship between the reference transmission pulse number N and the transmission pulse number M in a detection cycle.

[0096] Prior to this, the pulse parameter calculation unit 231 transmits the pulse parameter calculation unit via... Figure 5 The calculation method shown calculates the reference transmission pulse number Nmin required at the maximum vehicle speed Vmax and the reference transmission pulse number N required at the current vehicle speed V. Specifically, the transmission pulse parameter calculation unit 231 calculates the reference transmission pulse number N as if the current vehicle speed V is the maximum vehicle speed Vmax, assuming the current vehicle speed V exceeds the maximum vehicle speed Vmax.

[0097] When (reference number of transmitted pulses N / reference number of transmitted pulses Nmin) is below a threshold B (e.g., 4), that is, when the vehicle speed is relatively high, the transmission pulse parameter calculation unit 231 sets the reference number of transmitted pulses Nmin to the number of transmitted pulses M. In addition, the supplementary parameter calculation unit 232 sets the number of transmitted pulses M using the number of pulses I.

[0098] On the other hand, when (reference number of transmitted pulses N / reference number of transmitted pulses Nmin) exceeds a threshold B (e.g., 4), that is, when the vehicle speed is relatively slow, the transmission pulse parameter calculation unit 231 sets the transmission pulse number M to (reference number of transmitted pulses N / threshold B). In addition, the supplementary parameter calculation unit 232 sets the transmission pulse number M using the pulse number I.

[0099] Then, the supplementary parameter calculation unit 232 calculates the number of pseudo-received signals K using the following mathematical formula (4).

[0100] K = NM···(4)

[0101] For example, Figure 6 This example illustrates setting the reference pulse number Nmin required for one detection cycle to "16" when the vehicle speed is at its maximum. In this case, to reproduce the waveform of the quantity in one detection cycle, the number of pulses M needs to be at least "4" (more than 1 / 4 of the quantity in one detection cycle). Based on this idea, it is preferable to set the threshold B to "4". Moreover, when the vehicle speed is below the maximum, the reference pulse number N required for one detection cycle increases. In this case, by increasing the number of pulses M using (M = reference pulse number N / threshold B), it is possible to make the number of pulses M "4" or more (more than 1 / 4 of the quantity in one detection cycle).

[0102] (An example of sending and receiving signals)

[0103] Figures 7A to 7C This diagram illustrates an example of signals transmitted and received by a radar device 100 according to one embodiment. Figures 7A to 7C In the diagram, the upper solid line represents the waveform of the transmitted signal, which includes multiple transmit pulses; the lower solid line represents the waveform of the received signal, which includes multiple receive pulses; and the lower dotted line represents the waveform of the pseudo-received signal.

[0104] Figures 7A to 7C In one embodiment, a radar device 100 transmits a transmission signal comprising a plurality of frequency-modulated transmission pulses via a transmission unit 210. Correspondingly, in another embodiment, the radar device 100 receives a reflected signal comprising the same number of receive pulses as the transmission pulses via a receiving unit 220. Figures 7A to 7C In the example shown, regardless of the vehicle speed, the number of pulses sent and received is always "4".

[0105] On the other hand, Figures 7A to 7CIn the example shown, the number of pseudo-received signals K changes according to the change in the number of pulses (i.e., the reference number of transmitted pulses N) required to meet a given distance detection accuracy as the vehicle speed changes. Specifically, the number of pseudo-received signals K is increased corresponding to the case that the lower the vehicle speed, the more pulses (i.e., the reference number of transmitted pulses N) required to meet the given distance detection accuracy. Thus, the radar device 100 according to one embodiment suppresses power consumption by reducing the number of pulses of the actually transmitted signal and can falsely increase the number of pulses of the received signal, thereby enabling high-precision detection of the distance to an object.

[0106] (An example of a pseudo-received signal generation method)

[0107] For example, the pseudo-signal generation unit 234 can use the statistical method shown below to generate a pseudo-signal based on M received pulses X1, X2, ..., X... M To calculate the coefficient a that minimizes the prediction error. N Using the calculated coefficient a N To generate a false received signal. The statistical method shown below is one example, but the false signal generation unit 234 may also use other statistical methods to generate the false received signal.

[0108] First, the pseudo-signal generation unit 234 generates the signal by receiving pulses X2 to X3 using the following mathematical formula (5). M The linear coupling (weighted sum) is used to calculate the predicted value of the received pulse X1.

[0109] [Mathematical Expression 1]

[0110]

[0111] Next, the pseudo signal generation unit 234 calculates the difference between the measured value and the predicted value of the received pulse X1 as the backward error using the following mathematical formula (6).

[0112] [Mathematical Expression 2]

[0113]

[0114] Next, the pseudo-signal generation unit 234 uses the following mathematical formula (7) to receive pulse X. M-1 The linear coupling (weighted sum) of ~X1 is used to calculate the received pulse X. M The predicted value.

[0115] [Mathematical Expression 3]

[0116]

[0117] Next, the pseudo-signal generation unit 234 calculates the received pulse X using the following mathematical formula (8). MThe difference between the measured value and the predicted value is used as the forward error.

[0118] [Mathematical Expression 4]

[0119]

[0120] Next, the pseudo-signal generation unit 234 calculates the coefficients a2 to a1 that minimize the sum of the squares of the backward error and the forward error. N .

[0121] Then, the pseudo-signal generation unit 234 can use the calculated coefficients a2 to a N The following mathematical formula (9) is used to calculate the received pulse X. M+1 As a false received signal.

[0122] [Mathematical Expression 5]

[0123] X M+1 =a2*X M +a3*X M-1 +…+a M *X2…(9)

[0124] (Example of parking space image generation)

[0125] Next, refer to Figure 8 as well as Figure 9 An example of generating a parking space image of a radar device 100 according to one embodiment will be described. Figure 8 This is a diagram illustrating an example of generating a parking space image of a radar device 100 according to one embodiment. Figure 9 This is a diagram illustrating an example of a parking space image generated by a radar device 100 according to one embodiment.

[0126] Figure 8 This represents an example of vehicle 10 being parked in parking lot 14. For example... Figure 8 As shown, the radar device 100 mounted on the vehicle 10 has radar transmitters and receivers 100A at the left front corner and right front corner of the vehicle 10, respectively. Each radar transmitter and receiver 100A can transmit radar waves (transmit signals) to the detection area 12 at the left and right front of the vehicle, and can receive reflected signals from objects present in the detection area 12.

[0127] To generate an image of the parking space, vehicle 10 passes through passageway 14C between parking lot 14A on the left and parking lot 14B on the right of parking lot 14. Thus, radar transmitter / receiver 100A can scan (transmit and receive signals) the entire area of ​​parking lot 14A and parking lot 14B using each radar transmitter / receiver 100A.

[0128] Then, based on the scanning results of each radar transmitter-receiver 100A, the radar device 100 detects the distance to an object in the parking space 14A to the left of the vehicle 10 and the distance to an object in the parking space 14B to the right of the vehicle 10, according to each given detection cycle. Based on these detection results, such as Figure 9 As shown, it is possible to generate a parking space image 20 for parking lot 14.

[0129] At this time, as explained above, the radar device 100 suppresses the actual number of transmitted pulses M in each detection cycle and compensates for the insufficient number of received pulses with a spurious received signal, thereby suppressing power consumption and detecting the distance of the object with high accuracy.

[0130] like Figure 9 As shown, the parking space image 20 includes a parking space image 21, a parking space image 22, a vehicle image 23, and a parking frame image 24.

[0131] Parking lot image 21 is a plan view of parking lot 14A, with white indicating areas where objects exist and black indicating areas where no objects exist.

[0132] Parking lot image 22 is a plan view of parking lot 14B, with white indicating areas where objects exist and black indicating areas where no objects exist.

[0133] Vehicle image 23 is a planar image of vehicle 10, displayed in parking space image 20 at a position corresponding to the current position of vehicle 10. That is, in parking space image 20, the display position of vehicle 10 changes as vehicle 10 moves.

[0134] The parking frame image 24 is a rectangular frame image representing the space where the vehicle 10 can park. For parking space images 21 and 22, the parking frame image 24 represents the area above a given size in which the vehicle 10 can park in the area where no objects exist (the black part) as a rectangular frame.

[0135] One embodiment of the radar device 100 enables users (such as the driver of vehicle 10) to visually grasp the space in the parking lot 14 where the vehicle 10 can park by displaying such a parking space image 20 on the display 109.

[0136] The above describes one embodiment of the present invention in detail, but the present invention is not limited to these embodiments, and various modifications or alterations can be made within the scope of the spirit of the present invention as set forth in the claims.

[0137] This international application claims priority based on Japanese Patent Application No. 2021-107061, filed on June 28, 2021, the entire contents of which are incorporated herein by reference.

[0138] -Explanation of Figure Markers-

[0139] 10 vehicles

[0140] 12 Detection Areas

[0141] 14 Parking Lots

[0142] Parking spaces 14A and 14B

[0143] 14C pathway

[0144] 20 Parking space images

[0145] 21 Images of parking spaces

[0146] 22 Images of parking spaces

[0147] 23 Vehicle Images

[0148] 24. Capable of displaying parking frame images.

[0149] 100 radar devices

[0150] 100A Radar Transmitter / Receiver

[0151] 101 Radar Range Detection Department

[0152] 102 Camera Distance Detection Unit

[0153] 103 Vehicle Speed / Coordinate Detection Department

[0154] 104 Memory

[0155] 105 Radar Obstacle Map Generation Department

[0156] 106 Camera Obstacle Map Generation Unit

[0157] 107 Parking Space Inspection Department

[0158] 108 Parking Space Image Generation Unit

[0159] 109 Monitor

[0160] 210 Sending Department

[0161] 220 Receiving Department

[0162] 230 Signal Processing Department

[0163] 231 Transmit Pulse Parameter Calculation Unit

[0164] 232 Supplementary Parameter Calculation Department

[0165] 233 FET section

[0166] 234 Pseudo-signal generation unit

[0167] 235 Distance Detection Department.

Claims

1. A radar device, characterized in that, have: Vehicle speed acquisition unit acquires the vehicle's speed; The transmitting unit transmits a transmission signal to a region including a direction orthogonal to the direction of travel of the vehicle; The receiving unit receives the reflected signal of the transmitted signal sent by the transmitting unit; The spurious signal generation unit generates a number of spurious received signals corresponding to the speed of the vehicle obtained by the vehicle speed acquisition unit, based on the reflected signals received by the receiving unit. as well as The distance detection unit detects the distance to an object existing in a direction orthogonal to the vehicle's direction of travel based on the reflected signal received by the receiving unit and the spurious received signal generated by the spurious signal generation unit. The transmitting unit transmits a signal with fewer pulses than the reference number of pulses required to satisfy a given distance detection accuracy. The pseudo signal generation unit generates a pseudo received signal that is the difference between the number of reference transmitted pulses corresponding to the speed of the vehicle obtained by the vehicle speed acquisition unit and the number of pulses of the transmitted signal.

2. The radar device according to claim 1, wherein, The lower the speed of the vehicle obtained by the vehicle speed acquisition unit, the more reference transmission pulses are transmitted.

3. The radar device according to claim 1 or 2, wherein, The distance detection unit detects the distance to the object whose relative speed to the vehicle is zero.

4. The radar device according to claim 1 or 2, wherein, The pseudo-signal generation unit generates the pseudo-received signal based on the reflected signal received by the receiving unit using statistical calculations.

5. The radar device according to claim 1 or 2, wherein, The radar device includes a parking space detection unit that detects available parking spaces around the vehicle based on the distance to the object detected by the distance detection unit.

6. The radar device according to claim 5, wherein, The radar device includes a parking space image generation unit, which generates an image of the parking space detected by the parking space detection unit based on the distances to the plurality of objects detected by the distance detection unit.

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