Moving speed detection device and detection method

Abstract

To provide a moving speed detection device capable of estimating the moving speed of a radar device itself on the basis of radar data, enabling more accurate estimation of the moving speed.SOLUTION: A moving speed detection device 1 has: a radar unit 3 that outputs radar data; a signal processing unit 4 that performs frequency analysis on the radar data to generate a frequency spectrum and generates combination data including a distance R, relative velocity V, and received intensity I in the frequency spectrum; a received intensity integration unit 5 that uses only combination data where a value of the distance R falls within a predetermined range to integrate the received intensity I for each value of the relative velocity V within each partitioned region obtained by dividing the distance within the range into predetermined regions; and a moving speed estimation unit 6 that specifies, for each divided region, a value Vm of the relative speed V corresponding to the maximum of a received intensity integration value Is. The moving speed detection device 1 estimates, as moving speed of the device itself, the value of the relative speed of the farthest divided region among the divided regions when the received intensity integration value exceeds a predetermined threshold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device and method for detecting movement speed, and more particularly to a technology for estimating the movement speed of a radar device itself based on radar data obtained by processing reflected waves that are returned after radio waves transmitted from a radar are reflected off the surface of an object. [Background technology]

[0002] A known radar device having a mechanism for detecting a target and estimating the relative speed of the target is one that includes a radar antenna configured to repeatedly transmit and receive signals while rotating in a horizontal plane, a display that displays a radar image showing the position of targets around the device, and a speed estimation unit that estimates the relative speed between the device and the target in the radiation direction component of radio waves from the device (see Patent Document 1).

[0003] Furthermore, a known moving speed detection device has a mechanism for detecting a target and estimating the relative speed of the target. The moving speed detection device performs frequency analysis of radar data that emits a transmitted wave and receives a reflected wave that is the transmitted wave reflected by an object and returns. Using only data in the generated frequency spectrum where the value of the distance to the object falls within a predetermined range, the device integrates the received strength for each value of relative speed to calculate an integrated received strength value for each value of relative speed, and identifies the relative speed value corresponding to the maximum value of the integrated received strength value as the moving speed (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-266292 [Patent Document 2] Japanese Patent Publication No. 2022-023614 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the inventors have found that the moving speed detection device described in Patent Document 2 may cause the moving speed determined by the analysis results of radar data to be lower than the actual moving speed due to the influence of the azimuth angle of the detected object. In this case, the inventors have also found that when the distance to the detected object is short, the moving speed may be lower than when the distance is long.

[0006] Therefore, an object of the present invention is to provide a moving speed detection device and a moving speed detection method that can estimate the moving speed of the radar device itself based on radar data, and that can estimate the moving speed more accurately. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the moving speed detection device of the present invention comprises: a radar unit that emits a transmission wave, receives a reflected wave that is the transmission wave reflected by an object and returns, and outputs radar data; a signal processing unit that performs frequency analysis of the radar data to generate a frequency spectrum, and calculates the distance and relative speed to the object to generate combined data of the distance, the relative speed, and the reception strength in the frequency spectrum; a reception strength integration unit that uses only the combined data where the distance value is within a predetermined range to integrate the reception strength for each value of the relative speed for each divided area obtained by dividing the distance into a predetermined number of areas; and a moving speed estimation unit that identifies the value of the relative speed that corresponds to the maximum value of the reception strength integration value for each divided area, and is characterized in that if the reception strength integration value calculated for each divided area exceeds a predetermined threshold, the relative speed value of the divided area that is farthest from the other divided areas is output as the moving speed of the device itself.

[0008] In the moving speed detection device according to the present invention, the predetermined number into which the predetermined range of distance is divided may be set to be changeable according to the distance of the predetermined range.

[0009] In the moving speed detection device according to the present invention, the radar data may be data acquired using a frequency modulated continuous wave radar.

[0010] A method for detecting a moving speed according to the present invention includes the steps of: performing frequency analysis of radar data output from a radar device that emits a transmission wave and receives a reflected wave that is returned after the transmission wave is reflected by an object, generating a frequency spectrum; calculating the distance and relative velocity to the object, and generating combined data of the distance, the relative velocity, and the reception strength in the frequency spectrum; using only the combined data in which the distance value is within a predetermined range, calculating an integrated reception strength value for each value of the relative velocity for each divided region obtained by dividing the distance into a predetermined number of regions; and identifying, for each divided region, the value of the relative velocity that corresponds to the maximum value of the integrated reception strength value; and, if the integrated reception strength value calculated for each divided region exceeds a predetermined threshold, determining the relative velocity value for the divided region that is farthest from the other divided regions as the moving speed of the device itself. [Effects of the Invention]

[0011] According to the moving speed detection device and method of the present invention, the moving speed of the radar device itself can be estimated based on radar data. Therefore, by installing a radar device, it is possible to know the moving speed of various equipment, devices, vehicles, facilities, etc. from only the received data of one system of the receiving antenna. In particular, using only data in which the distance value from the object in the frequency spectrum falls within a predetermined range, the predetermined distance range is divided into a predetermined number of regions, and an integrated reception intensity value is calculated for each divided region. If the integrated reception intensity value exceeds a predetermined threshold, the relative speed value of the farthest region among the divided regions is estimated as the moving speed of the device itself. This prevents erroneous estimation and enables more accurate moving speed estimation.

[0012] According to the moving speed detection device of the present invention, the predetermined number into which the predetermined distance range is divided is set to be changeable according to the distance of the predetermined range, so that it is possible to estimate the moving speed more accurately according to the distance.

[0013] The moving speed detection device according to the present invention can achieve the above-mentioned effects when combined with a frequency-modulated continuous wave radar. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a functional block diagram showing a schematic configuration of a moving speed detection device according to an embodiment of the present invention; [Figure 2] 2 is a flowchart showing the processing procedure in the moving speed detection device of FIG. 1 and the processing procedure of the moving speed detection method according to the embodiment of the present invention. [Figure 3] 1A is a diagram showing an example of VR data output from a signal processing unit, and FIG. 1B is a diagram showing the relationship between relative speed and integrated received intensity value for the VR data of FIG. [Figure 4] 1A is a diagram showing an example of setting an intensity integration distance range and divided regions for VR data output from a signal processing unit, and FIG. 1B is a diagram showing the relationship between relative speed and received intensity integration value for the VR data of FIG. 1A when the intensity integration distance range is taken into account. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described below based on the illustrated embodiments. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0016] Fig. 1 is a functional block diagram showing a schematic configuration of a moving speed detection device according to an embodiment of the present invention. Fig. 2 is a flowchart showing the processing procedure in the moving speed detection device 1 and the processing procedure of the moving speed detection method according to the embodiment of the present invention.

[0017] The moving speed detection device 1 is a device that estimates the moving speed of the device itself based on radar data acquired by a radar, and mainly comprises a control unit 2, a radar unit 3, a signal processing unit 4, a reception intensity integrating unit 5, and a moving speed estimation unit 6. As just one example, the moving speed detection device 1 is mounted on a vehicle such as a train or an automobile, and is used to estimate the moving speed / traveling speed of the vehicle by calculating the relative speed of the device itself (vehicle) with respect to a stationary target that exists near the moving vehicle, and estimating the moving speed of the moving speed detection device 1 itself.

[0018] The control unit 2 is a mechanism for controlling each part of the moving speed detection device 1, and is configured as a mechanism including a central processing unit 21 (CPU: Central Processing Unit) that performs calculations related to the detection of moving speed, a readable storage device ROM22 (ROM: Read Only Memory), and a readable / writable storage device RAM23 (RAM: Random Access Memory).

[0019] The control unit 2 uses the RAM 23 as a working area as needed, by having the central processing unit 21 execute a program for controlling the operation of the movement speed detection device 1, which is stored in the ROM 22, and controls the start, content, and end of processing of each part of the movement speed detection device 1 in accordance with the program.

[0020] The moving speed detection device 1 according to this embodiment includes a radar unit 3 that emits a transmission wave and receives a reflected wave that is the transmission wave reflected by an object and returns, and outputs radar data; a signal processing unit 4 that performs frequency analysis of the radar data to generate a frequency spectrum and calculates the distance R and relative velocity V to the object to generate combined data of the distance R, the relative velocity V, and the receiving intensity I in the frequency spectrum; a receiving intensity integration unit 5 that divides a predetermined distance range into a predetermined number of regions, and integrates the receiving intensity I for each value of the relative velocity V for each divided region using only the combined data where the value of the distance R is within a predetermined range; and a moving speed estimation unit 6 that identifies the value Vm of the relative velocity V corresponding to the maximum value Ismax of the receiving intensity integrated value Is for each divided region (see FIG. 1).

[0021] Furthermore, the method for detecting the moving speed according to this embodiment includes the following steps (steps S1 to S4): performing frequency analysis of radar data output from a radar unit 3 (radar device) that emits a transmission wave and receives a reflected wave that is returned after the transmission wave is reflected by an object, generating a frequency spectrum, and calculating a distance R and a relative velocity V to the object to generate combined data of the distance R, the relative velocity V, and the reception intensity I in the frequency spectrum; using only the combined data in which the value of the distance R is within a predetermined range, a process (step S5) dividing the predetermined range of distance into a predetermined number of regions, and integrating the reception intensity I for each value of the relative velocity V for each divided region to calculate an integrated reception intensity value Is for each value of the relative velocity V; and a process (step S6) identifying the value Vm of the relative velocity V corresponding to the maximum value Ismax of the integrated reception intensity value Is for each divided region (see FIG. 2).

[0022] The radar unit 3 has a transmitting unit 31 and a receiving unit 32 and has the function of transmitting and receiving radio waves, and outputs radar data acquired by performing a radar scan using, for example, an FMCW (Frequency Modulated Continuous Wave) radar method.

[0023] In the FMCW method, a frequency-modulated continuous wave (specifically, radio waves; equivalent to a transmission signal) is transmitted as a transmission wave, and a reflected wave (specifically, radio waves; equivalent to a reception signal) that is reflected off the surface of the object is received. The distance between the radar unit 3 and the object is calculated by analyzing the difference between the transmitted wave and the received wave (i.e., the reflected wave) (in other words, the frequency difference between the transmitted wave and the received wave). The relative speed between the radar unit 3 and the object is also calculated by measuring and analyzing the phase of the frequency of the calculated distance for each continuous wave.

[0024] FMCW radar is a continuous wave radar that modulates frequency over time, generating and transmitting (in other words, emitting or radiating) a burst wave containing multiple chirps. Each chirp contained in the burst wave is generated by sweeping the frequency over time, so that the frequency changes linearly (specifically, increases / decreases) over time. The modulation width and modulation period of the chirp frequency (i.e., the chirp repetition period) may be adjusted as appropriate.

[0025] Here, multiple chirps are transmitted at a predetermined time interval, and a series of these chirps is called a "chirp frame." One chirp frame corresponds to one radar scan, and each chirp frame is processed independently.

[0026] The transmitter 31 of the radar unit 3 is configured as a mechanism including, for example, a voltage generator, a voltage-controlled oscillator, and a transmitting antenna. The voltage generator generates and outputs a control voltage that changes in a triangular (or sawtooth) waveform, with successive alternating periods of gradually increasing level and gradually decreasing level on the time axis. The voltage-controlled oscillator generates and outputs a transmission signal that changes in a triangular (or sawtooth) waveform, with successive alternating periods of gradually increasing frequency and gradually decreasing frequency on the time axis, in response to the control voltage. The transmitting antenna generates a transmission wave based on the transmission signal and radiates it as a transmission wave into the space around the vehicle or the like on which the moving speed detection device 1 is mounted (referred to as the "surrounding space"; it is preferable that this space includes the space along the traveling direction of the vehicle or the like). A portion of the transmission signal is also transmitted to the receiver 32 as a local signal at a predetermined distribution ratio.

[0027] The transmitter 31 generates radio waves (also called "millimeter waves") having a frequency of, for example, 79 GHz, 76 GHz, or 60 GHz, and radiates the radio waves into the surrounding space via a transmitting antenna. In the present invention, it is preferable to use radio waves in a high frequency band.

[0028] The receiver 32 of the radar unit 3 is configured as a mechanism including, for example, a receiving antenna, a mixer, and an A / D converter. The receiver antenna receives, as received waves, radio waves emitted from the transmitter antenna of the transmitter 31 (i.e., transmitted waves) that are reflected off the surfaces of objects in the surrounding space and return (i.e., reflected waves; also called "Doppler reflected waves"), and converts the received received waves / reflected waves into received signals and outputs them. The mixer mixes the radio waves distributed and transmitted from the transmitter 31 (transmitted signals; i.e., local signals) with the radio waves output from the receiving antenna (received signals) to generate and output a differential signal (an analog signal). The A / D converter performs sampling processing (in other words, analog-to-digital conversion processing) on ​​the differential signal output from the mixer using a predetermined sampling frequency, converts the differential signal into digital data, and outputs the digitized differential signal.

[0029] The differential signal as radar data output from the radar unit 3 after a radar scan is a signal having a frequency component that is the difference between the frequency component of the radio wave (transmission signal; i.e., local signal) distributed and transmitted from the transmission unit 31 and the frequency component of the radio wave (reception signal) output from the receiving antenna (i.e., a signal having a beat frequency, also called a "beat signal").

[0030] Every time a radar scan is performed, radar data is output from the radar unit 3 and input to the signal processing unit 4 (step S1).

[0031] The signal processing unit 4 performs frequency analysis of the radar data output from the radar unit 3, and calculates distance information and relative velocity information regarding the object that reflected the transmitted wave using the frequency analysis results. The signal processing unit 4 includes a frequency analysis unit 41, a distance calculation unit 42, and a velocity calculation unit 43.

[0032] The frequency analysis unit 41 performs frequency analysis of the differential signal (beat signal) as radar data (in other words, beat waveform data) output from the radar unit 3 (specifically, the A / D converter of the receiving unit 32) (step S2).

[0033] Specifically, the frequency analysis unit 41 performs a fast Fourier transform (FFT) on beat waveform data for a sampling time width (e.g., 100 milliseconds) per radar scan, specifically the amplitude of the differential signal (beat signal), to generate and output a frequency spectrum (beat frequency spectrum) that indicates the frequency distribution of the amplitude of the differential signal. The frequency spectrum indicates the amplitude of each frequency component included in the differential signal.

[0034] The amplitude and frequency bins (or FFT bins) in the frequency spectrum correspond to the received intensity and beat frequency of the reflected wave from an object. The received intensity and beat frequency in the frequency spectrum provide distance and relative velocity information about the object, i.e., the distance and relative velocity of the object that reflected the transmitted wave.

[0035] The distance calculation unit 42 calculates and outputs the distance R between the radar unit 3 and the object based on the frequency spectrum output from the frequency analysis unit 41 (step S3). The distance R is calculated for each frequency bin in the frequency spectrum as a result of the frequency analysis in the processing of step S2.

[0036] There are known methods for calculating distance based on frequency spectrum, and the present invention is not limited to a specific method, so detailed explanation will be omitted here. For example, the distance between the radar unit 3 and an object that reflects the transmitted wave can be calculated by a known method such as a method that utilizes the fact that the difference between the frequency of the transmitted wave and the frequency of the received wave increases or decreases in proportion to the distance between the radar unit 3 and the object.

[0037] The velocity calculation unit 43 calculates and outputs the relative velocity V between the radar unit 3 and the object (specifically, the instantaneous relative velocity when the transmitted wave is reflected by the surface of the object) based on the frequency spectrum output from the frequency analysis unit 41 (step S4). The relative velocity V is calculated for each frequency bin in the frequency spectrum as a result of the frequency analysis in the processing of step S2.

[0038] There are known methods for calculating the relative velocity based on the frequency spectrum, and the present invention is not limited to a specific method, so a detailed description will be omitted here. For example, the relative velocity between the radar unit 3 and an object can be calculated by a known method, such as a method that utilizes the fact that when the radar unit 3 and an object that reflects the transmitted waves are moving relative to each other, the frequency of the radio waves reflected by the surface of the object and received by the receiving antenna (i.e., the received waves) is affected by the relative velocity of the radio waves when reflected by the surface of the object and the radar unit 3, and shifts due to the Doppler effect in accordance with the relative velocity between the radar unit 3 and the object, compared to the frequency of the radio waves transmitted from the transmitting antenna (i.e., the transmitted waves).

[0039] The signal processing unit 4 performs the above processing and outputs data (V, R, I) consisting of a combination of the relative speed V (unit: km / h) between the radar unit 3 and an object, the distance R (unit: m) between the radar unit 3 and the object, and the reception intensity I, which is the absolute value of the amplitude for each frequency bin, calculated for each frequency bin in the frequency spectrum as a result of the frequency analysis based on the radar data output from the radar unit 3. The data (V, R, I) output from the signal processing unit 4 is called "VR data."

[0040] In addition, when the distance R and relative velocity V are calculated for each frequency bin in the frequency spectrum, if there are multiple combinations of the same distance R value and relative velocity V value, the sum of the values ​​of reception intensity I for each combination of the same distance R value and relative velocity V value is used as the value of reception intensity I for the combination of the distance R value and relative velocity V value.

[0041] The signal processing unit 4 performs processing for each radar scan of a predetermined time period (in other words, a sampling time width). That is, each time a radar scan is performed, a set of VR data (V, R, I) related to the radar scan is generated and output.

[0042] An example of VR data (V, R, I) is shown in Figure 3(A). In Figure 3(A), the horizontal axis represents relative velocity V and the vertical axis represents distance R, and the value of reception strength I corresponding to the combination of (V, R) is displayed in different colors depending on the magnitude of the value.

[0043] Here, the VR data (V, R, I) includes relative velocity components that correspond to (in other words, are equivalent to) the moving speed of the moving speed detection device 1 itself, which are caused by reflected waves from surrounding stationary objects (for example, the ground / road surface, structures, or equipment fixedly installed on the ground / land; referred to as "stationary targets"). In this invention, the moving speed of the moving speed detection device 1 itself is estimated by focusing on the reflected waves from the stationary targets. In other words, in this invention, the moving speed of the moving speed detection device 1 itself is estimated by calculating the relative speed of the device itself with the stationary targets as a reference.

[0044] The reception intensity integrator 5 calculates the reception intensity integrated value for each value of the relative velocity for the set of VR data (V, R, I) output from the signal processor 4 (step S5).

[0045] The reception intensity integrating unit 5 uses a set of VR data (V, R, I) to integrate the value of reception intensity I for each value of relative velocity V to calculate an integrated reception intensity value Is for each value of relative velocity V. The integrated reception intensity value Is is an integrated value of reception intensity I in the direction of distance R for each value of relative velocity V on a VR plane such as that shown in FIG. 3, which is configured by the set of VR data (V, R, I). Note that the reception intensity integrating unit 5 may, as necessary, divide the value of relative velocity V into predetermined intervals and integrate the value of reception intensity I for each speed rank (in other words, speed bin).

[0046] Figure 3(B) shows a set of combined data (V, Is) of relative velocity V and integrated reception intensity value Is, calculated using the set of VR data (V, R, I) shown in Figure 3(A). In Figure 3(B), the horizontal axis represents relative velocity V, and the vertical axis represents integrated reception intensity value Is.

[0047] In the prior art, in order to calculate the relative speed of the device with respect to a stationary target, it is necessary to exclude the reception strength of the reflected waves from objects / structures near the radar unit 3 that are moving together with the radar unit 3. Therefore, when calculating the integrated reception strength value Is, the value of the reception strength I is integrated for each value of the relative speed V within a specific range of the distance R calculated in the processing of step S3. The range of the distance R used when calculating the integrated reception strength value Is is called the "intensity integrated distance range."

[0048] Specifically, when calculating the received intensity integrated value Is, the directivity of the transmitting / receiving antenna is taken into consideration, as well as the following items, and the range of the distance R is then limited and the intensity integrated distance range is appropriately set to an appropriate range. The range where an object exists in the vicinity of the radar unit 3, moves together with the moving speed detection device 1, and the value of the relative speed V with respect to the moving speed detection device 1 is 0 is excluded. Excluding areas where it is clear that there are moving objects relative to the ground / land. For example, when the moving speed detection device 1 is installed on a railway and estimates the traveling speed of the railway, it excludes the area where other railways are traveling (e.g., the area of ​​adjacent tracks), or when the moving speed detection device 1 is installed on a car and estimates the traveling speed of the car, it excludes the area where other cars are traveling (e.g., the area of ​​adjacent lanes). Excludes areas where there are no stationary targets or areas where the received strength of the reflected waves is extremely weak even if there are stationary targets.

[0049] As the intensity accumulation distance range, only a lower limit may be set for the range of distance R (i.e., only the value of the reception intensity I of VR data where the value of distance R is equal to or greater than a predetermined value is accumulated), or only an upper limit may be set (i.e., only the value of the reception intensity I of VR data where the value of distance R is equal to or less than a predetermined value is accumulated), or both a lower limit and an upper limit may be set (i.e., only the value of the reception intensity I of VR data where the value of distance R is equal to or greater than a predetermined value and less than a predetermined value is accumulated).

[0050] For the VR data (V, R, I) shown in Fig. 3(A), if the intensity integration distance range is set as shown in Fig. 4(A) and the received intensity integrated value Is is calculated, the result will be as shown in Fig. 4(B). In the example shown in Fig. 4, the lower limit of the intensity integration distance range is set to 10 m and the upper limit is set to 32 m, just as an example.

[0051] 3(B), peaks A, B, and C are peaks related to the reception strength of the reflected waves from a stationary target, and are peaks related to the reception strength corresponding to the movement speed of the movement speed detection device 1 itself. When the movement speed detection device 1 and a surrounding object are moving relatively closer to each other, the peaks related to the reception strength corresponding to the movement speed of the movement speed detection device 1 itself appear in a region where the value of the relative speed V is positive (it is also possible to make them appear in a negative region depending on the calculation formula used).

[0052] In this case, in a conventional moving speed detection device, the value of the relative speed corresponding to the maximum value of the integrated reception intensity is identified as the moving speed, and therefore the relative speed V corresponding to peak A shown in Fig. 3(B) is the maximum value, and the value Vm of the relative speed V corresponding to peak A is identified as the moving speed. However, as described above, due to the influence of the azimuth angle of the detected object, the relative speed may be lower than the actual moving speed, and in this case, if the distance to the detected object is close, the moving speed may be lower than if the object is far away.

[0053] Therefore, in this invention, as shown in Figure 4(A), the set intensity integration distance range is further divided into a predetermined number of divided areas (for example, three), areas 11, 12, and 13 in the example shown in Figure 4(A), and the received intensity integration value Is is calculated for each divided area (areas 11, 12, and 13).

[0054] The reception intensity integrating unit 5 sets an intensity integration distance range for the VR data (V, R, I), integrates the value of the reception intensity I for each value of the relative velocity V using only the VR data (V, R, I) whose value of the distance R falls within the intensity integration distance range, and outputs a set of data (V, Is) consisting of a combination of the relative velocity V and the reception intensity integrated value Is for each divided area (areas 11, 12, 13). The data (V, Is) output from the reception intensity integrating unit 5 is called "reception intensity integrated value data."

[0055] The moving speed estimating unit 6 estimates the moving speed of the moving speed detecting device 1 itself using the set of reception intensity integrated value data (V, Is) output from the reception intensity integrating unit 5 (step S6).

[0056] The moving speed estimation unit 6 identifies the maximum value Ismax of the integrated reception strength value Is from the set of integrated reception strength data (V, Is), and identifies and outputs the value Vm of the relative speed V combined with the identified maximum value Ismax of the integrated reception strength value Is.

[0057] As described above, when the distance to the detected object is short, the moving speed may be lower than when the distance is long, so the moving speed estimation unit 6 determines that the integrated reception intensity value Is calculated for each divided area (areas 11, 12, 13) is a candidate for the maximum value Ismax when it exceeds a predetermined threshold as shown in Fig. 4(B).Then, it identifies and outputs the value Vm of the relative speed V of the area that is farthest from the divided areas (areas 11, 12, 13).

[0058] For example, in FIG. 4(B), Peak A is the integrated value of the received signal strength in region 13, Peak B is the integrated value of the received signal strength in region 12, and Peak C is the integrated value of the received signal strength in region 11. Peaks A, B, and C all exceed the threshold, and therefore are candidates for the maximum value Ismax. As shown in FIG. 4(A), region 11 is the farthest region, and therefore the value Vm of the relative speed V corresponding to peak C is identified as the moving speed. This makes it possible to prevent the relative speed from becoming a value lower than the actual moving speed.

[0059] Here, the divided regions are divided into three regions 11, 12, and 13, but the number of divisions (predetermined number of divisions) is not limited to 3. For example, the number of divisions may be changed according to the range of distance R, which is the intensity integrated distance range, and the number of divisions may be increased if the range of distance R is long.

[0060] Furthermore, the predetermined threshold value is not limited to a specific value, and may take into consideration the characteristics related to the output of the radar unit 3, and may be a value that can distinguish whether the radar data is received in good conditions with no (or few) disturbances, etc., so that a peak in the reception intensity corresponding to an object reflecting the transmission wave can accurately appear, or whether the radar data is received in conditions that are not good due to disturbances, etc., so that a peak in the reception intensity corresponding to an object reflecting the transmission wave cannot accurately appear, and then the predetermined threshold value is appropriately set.

[0061] According to the moving speed detection device 1 and the moving speed detection method of the embodiment, only data in which the value of the distance R to the object in the frequency spectrum falls within a predetermined range is used, and the predetermined distance range is divided into a predetermined number of regions, and an integrated reception strength value is calculated for each divided region. If the integrated reception strength value exceeds a predetermined threshold, the value of the relative speed of the divided region with the farthest distance is estimated as the moving speed of the device itself. This prevents erroneous estimation and enables more accurate estimation of the moving speed.

[0062] Furthermore, the predetermined number into which the predetermined distance range is divided is set to be changeable according to the distance of the predetermined range, which allows for more accurate estimation of the moving speed according to the distance.

[0063] The above describes an embodiment of the present invention, but the specific configuration is not limited to the above embodiment, and even if there are design changes within the scope of the present invention that do not deviate from the gist of the present invention, they are included in the present invention.

[0064] Specifically, in the above embodiment, the FMCW method is used as the radar method, but the use of the FMCW method as the radar method is not an essential configuration for the present invention, and any radar method may be used as long as it can generate the VR data (V, R, I) in the above embodiment. In this respect, the specific configurations of the radar unit 3 and the signal processing unit 4 in the above embodiment are not limited to the configurations in the above embodiment. [Explanation of symbols]

[0065] 1:Detection device 2: Control section 3: Radar section 4: Signal processing section 5: Reception strength integrator 6: Moving speed estimator 11~13: area 21: Central processing unit 22:ROM 23:RAM 31: Transmitter 32: Receiving unit 41: Frequency analysis section 42: Distance calculation section 43: Speed ​​calculation section I: Reception strength Is: Integrated reception strength Ismax: Maximum value of Is R: Distance V: Relative velocity Vm: The value of relative velocity V corresponding to Ismax

Claims

1. a radar unit that emits a transmission wave, receives a reflected wave that is the transmission wave reflected by an object and returns, and outputs radar data; a signal processing unit that performs frequency analysis of the radar data to generate a frequency spectrum, and calculates a distance and a relative velocity to the object to generate combined data of the distance, the relative velocity, and the reception intensity in the frequency spectrum; a reception intensity integrating unit that calculates an integrated reception intensity value for each value of the relative velocity by integrating the reception intensity for each divided region obtained by dividing the distance range into a predetermined number of regions using only the combination data in which the distance value is within a predetermined range; and a moving speed estimating unit that identifies the value of the relative speed corresponding to the maximum value of the integrated reception intensity value for each of the divided areas, If the integrated value of the reception intensity calculated for each of the divided areas exceeds a predetermined threshold, the value of the relative speed of the area that is farthest from the divided areas is output as the moving speed of the device itself. A moving speed detection device characterized by:

2. The predetermined number into which the distance of the predetermined range is divided is set to be changeable according to the distance of the predetermined range.

2. The moving speed detection device according to claim 1.

3. The radar data is data acquired using a frequency-modulated continuous wave radar.

3. The moving speed detection device according to claim 1 or 2.

4. a process of performing frequency analysis of radar data output from a radar device that emits a transmission wave and receives a reflected wave that is the transmission wave reflected by an object, generating a frequency spectrum, and calculating a distance and relative velocity to the object to generate combined data of the distance, the relative velocity, and the reception intensity in the frequency spectrum; a process of dividing the predetermined distance range into a predetermined number of regions, and integrating the reception strength for each of the divided regions for each value of the relative speed, using only the combination data in which the distance value is within a predetermined range; and and a process of identifying the value of the relative speed corresponding to the maximum value of the integrated value of the reception intensity for each of the divided areas, If the integrated value of the received signal strength calculated for each of the divided areas exceeds a predetermined threshold, the value of the relative speed of the area that is farthest from the divided areas is set as the moving speed of the device itself. A method for detecting a moving speed.

5. The predetermined number into which the distance of the predetermined range is divided is set to be changeable according to the distance of the predetermined range.

5. The method for detecting a moving speed according to claim 4.

6. The radar data is data acquired using a frequency-modulated continuous wave radar.

6. The method for detecting a moving speed according to claim 4 or 5.

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