Apparatus and method for detecting moving speed

Abstract

To enable estimating a moving speed of a radar device itself on the basis of radar data.SOLUTION: A moving speed detection device has: a radar unit 3 that radiates a transmission wave, and after the transmission wave is reflected upon an object, receives a returning reflected wave; a signal processing unit 4 that performs a frequency analysis of the radar data to generate a frequency spectrum, calculate a distance R to the object. and a relative speed V, and then, generates combination data on reception intensity in the distance R, the relative speed V, and the frequency spectrum; a reception intensity integration unit 5 that integrates the reception intensity I every a value of the relative speed I using only the combination data in which a value of the distance R falls within a prescribed range, and calculates a reception intensity integration value Is by a value of the relative speed V; a moving speed estimation unit 6 that identifies a value Vm of the relative speed V corresponding to a maximum value Ismax of the reception intensity integration value Is; and a reliability degree determination unit 7 that calculates a speed reliability degree IR on the basis of a relation between the maximum value Ismax of the reception intensity integration value Is and an average value of the reception intensity integration value Is at least excluding the maximum value Ismax.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device and method for detecting moving speed, and in particular to a technology for estimating the moving 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 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 positions 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). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-266292 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, if it were possible to estimate the moving speed of the radar device itself based on radar data acquired using a radio wave sensor / radar device, it would be useful to know the moving speeds of various equipment, devices, vehicles, facilities, etc. by installing the radio wave sensor / radar device.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an apparatus and method for detecting a moving speed that are capable of estimating the moving speed of a radar device itself based on radar data. [Means for solving the problem]

[0006] In order to solve the above problem, the invention described in claim 1 is a moving speed detection device comprising: a radar unit that emits a transmission wave, receives a reflected wave of the transmission wave that is 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 integrates the reception strength for each value of the relative speed using only the combined data in which the distance value is within a predetermined range, to calculate an integrated reception strength value for each value of the relative speed; a moving speed estimation unit that identifies the value of the relative speed corresponding to the maximum value of the integrated reception strength value; and a reliability determination unit that calculates a speed reliability based on the relationship between the maximum value of the integrated reception strength value and at least an average value of the integrated reception strength value excluding the maximum value, wherein the identified value of the relative speed is output as the moving speed of the device itself, and a value calculated by taking a weighted average of past moving speed values ​​and latest moving speed value using a weight determined according to the value of the speed reliability is output as the moving speed of the device itself.

[0007] The invention described in claim 2 is characterized in that, in the moving speed detection device described in claim 1, the radar data is data acquired using a frequency modulated continuous wave radar.

[0008] The invention described in claim 3 is a method for detecting a moving speed, comprising 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, and calculating a distance and relative speed to the object to generate combined data of the distance, the relative speed, and the receiving strength in the frequency spectrum; integrating the receiving strength for each value of the relative speed using only the combined data in which the distance value is within a predetermined range to calculate an integrated receiving strength value for each value of the relative speed; identifying a value of the relative speed corresponding to a maximum value of the integrated receiving strength value; and calculating a speed reliability based on a relationship between the maximum value of the integrated receiving strength value and at least an average value of the integrated receiving strength value excluding the maximum value, wherein the identified value of the relative speed is set as the moving speed of the device itself, and a value calculated by taking a weighted average of past moving speed values ​​and latest moving speed value using a weight determined according to the value of the speed reliability is set as the moving speed of the device itself.

[0009] The invention described in claim 4 is characterized in that, in the moving speed detection method described in claim 3, the radar data is data acquired using a frequency modulated continuous wave radar. Effect of the Invention

[0010] According to the inventions recited in claims 1 and 3, the moving speed of the radar device itself can be estimated based on radar data, so that by installing a radar device, it becomes possible to know the moving speeds of various equipment, devices, vehicles, facilities, etc., from only the data received from one receiving antenna. According to the inventions recited in claims 1 and 5, in particular, the moving speed of the device itself is estimated using the integrated value of the reception intensity for each value of the relative speed calculated using only data whose distance value is within a predetermined range, so that it is possible to prevent erroneous estimation and more accurately estimate the moving speed of the device itself in various environments.

[0011] In addition, according to the invention described in claim 1 and claim 3, it is possible to prevent the output of abnormal values ​​of the estimated moving speed when the reception strength is significantly reduced due to external disturbances, etc., and output a value that is a weighted average of the past moving speed value and the latest moving speed value based on their respective reliability, thereby making it possible to avoid sudden fluctuations in the estimated moving speed value and maintain the continuity of the estimated moving speed value, and ultimately to improve the reliability of the technology for estimating moving speed by suppressing the impact of a short-term decrease in reception strength on the estimated moving speed value.

[0012] According to the invention recited in claim 2 and claim 4, the above-mentioned advantageous effects can be achieved by combining with a frequency modulated continuous wave radar. [Brief description of the drawings]

[0013] [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; [Diagram 2] 2 is a flowchart showing a processing procedure in the moving speed detection device of FIG. 1 and also a processing procedure of a moving speed detection method according to the embodiment of the present invention. [Diagram 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 the relative speed and the integrated reception intensity value for the VR data of FIG. [Figure 4] 1A is a diagram showing an example of setting an intensity integration distance range for VR data output from a signal processing unit, and FIG. 1B is a diagram showing the relationship between the relative speed and the received intensity integration value when the intensity integration distance range is taken into account for the VR data of FIG. [Diagram 5] FIG. 11 is a diagram for explaining the content of calculation of speed reliability. [Figure 6] 10 is a flowchart showing another processing procedure in the moving speed detection device of FIG. 1 and also showing a processing procedure of a moving speed detection method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the present invention will be described based on the illustrated embodiment.

[0015] Fig. 1 is a functional block diagram showing a schematic configuration of a moving speed detection device 1 according to an embodiment of the present invention. Fig. 2 is a flowchart showing a processing procedure in the moving speed detection device 1 and a processing procedure of a moving speed detection method according to the embodiment of the present invention.

[0016] The moving speed detection device 1 is a mechanism for estimating the moving speed of the device itself based on radar data acquired by a radar, and mainly includes a control unit 2, a radar unit 3, a signal processing unit 4, a reception intensity integrating unit 5, a moving speed estimating unit 6, and a reliability determining unit 7. For example, as merely 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 estimating the moving speed of the moving speed detection device 1 itself.

[0017] The control unit 2 is a mechanism for controlling each part of the moving speed detection device 1, and is configured as a mechanism equipped with a central processing unit 21 (CPU: abbreviation for Central Processing Unit) that performs calculations related to the detection of moving speed, a ROM 22 (ROM: abbreviation for Read Only Memory) which is a readable storage device, and a RAM 23 (RAM: abbreviation for Random Access Memory) which is a readable / writable storage device.

[0018] The control unit 2 uses the RAM 23 as a working area as necessary by executing a program for controlling the operation of the moving speed detection device 1, stored in the ROM 22, via the central processing unit 21, and coordinates and controls the start, content, and end of processing of each part of the moving speed detection device 1 in accordance with the program, while using the RAM 23 as a working area as necessary.

[0019] The moving speed detection device 1 of this embodiment has a radar unit 3 that emits a transmission wave and receives a reflected wave that is 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 calculates the receiving intensity integrated value Is for each value of the relative velocity V by integrating the receiving intensity I for each value of the relative velocity V using only the combined data in which the value of the distance R is within a predetermined range; and a moving speed estimation unit 6 that specifies the value Vm of the relative velocity V corresponding to the maximum value Ismax of the receiving intensity integrated value Is (see FIG. 1).

[0020] The moving speed detection device 1 according to this embodiment further calculates a speed reliability I based on the relationship between the maximum value Ismax of the integrated reception strength value Is and the average value Isavg of the integrated reception strength value Is excluding at least the maximum value Ismax. R The reliability determination unit 7 further calculates the speed reliability I R The value of the moving speed of the own device is not updated for a predetermined period of time according to the value of (see FIG. 1).

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

[0022] The method for detecting the moving speed according to this embodiment further includes: calculating a speed reliability I based on the relationship between the maximum value Ismax of the integrated reception strength value Is and an average value Isavg of the integrated reception strength value Is excluding at least the maximum value Ismax. R The method further includes a process of calculating the speed reliability I R The value of the moving speed of the own device is not updated for a predetermined period of time according to the value of (steps S8, S10, S11) (see FIG. 2).

[0023] The radar unit 3 is equipped with a transmitter 31 and a receiver 32 and has the function of transmitting and receiving radio waves, and outputs radar data acquired by performing a radar scan using a radar method such as FMCW (abbreviation for Frequency Modulated-Continuous Wave).

[0024] In the FMCW method, a frequency-modulated continuous wave (specifically, radio waves; equivalent to the transmitted signal) is transmitted as the transmitted wave, and a reflected wave (specifically, radio waves; equivalent to the received signal) that reflects off the surface of the object is received. 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) is analyzed to calculate the distance between the radar unit 3 and the object, and the relative speed between the radar unit 3 and the object is calculated by measuring and analyzing the phase of the frequency of the calculated distance for each continuous wave.

[0025] FMCW radar is a continuous wave radar that performs frequency modulation over time, and generates and transmits (in other words, emits or radiates) 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 over time (specifically, increases / decreases). The modulation width and modulation period of the chirp frequency (i.e., the repetition period of the chirp) may be adjusted as appropriate.

[0026] Here, multiple chirps are transmitted at a predetermined time interval, and a series of multiple chirps that form a single unit is called a "chirp frame." One chirp frame corresponds to one radar scan, and each chirp frame is processed independently.

[0027] The transmitting section 31 of the radar section 3 is configured as a mechanism including, for example, a voltage generator, a voltage controlled oscillator, and a transmitting antenna.

[0028] The voltage generator generates and outputs a control voltage that changes in a triangular (or sawtooth) waveform, with successive alternating sections on the time axis where the level gradually increases and sections where the level gradually decreases.

[0029] The voltage-controlled oscillator generates and outputs a transmission signal in which modulation sections in which the frequency gradually increases and modulation sections in which the frequency gradually decreases on the time axis alternate in succession, forming a triangular wave (or a sawtooth wave) in response to the control voltage.

[0030] The transmitting antenna generates a transmission wave based on the transmission signal, and radiates the wave to the space around the vehicle on which the moving speed detection device 1 is mounted (referred to as the "surrounding space"; it is preferable that the space includes a space along the traveling direction of the vehicle). A part of the transmission signal is also transmitted to the receiving unit 32 as a local signal at a predetermined distribution ratio.

[0031] 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 transmission antenna. In the present invention, it is preferable to use radio waves in a high frequency band.

[0032] The receiving section 32 of the radar unit 3 is configured as a mechanism including, for example, a receiving antenna, a mixer, and an A / D converter.

[0033] The receiving antenna receives radio waves as received waves, including radio waves that are emitted from the transmitting antenna of the transmitting unit 31 (i.e., transmitted waves) and are reflected off the surface of an object in the surrounding space and return (i.e., reflected waves; also called "Doppler reflected waves"), and converts the received received waves / reflected waves into a received signal and outputs it.

[0034] The mixer mixes the radio waves (transmission signal; i.e., local signal) distributed and transmitted from the transmitter 31 with the radio waves (received signal) output from the receiving antenna to generate and output a differential signal (which is an analog signal).

[0035] 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.

[0036] The differential signal output as radar data from the radar unit 3 after a radar scan is a signal having a frequency component which 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").

[0037] 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).

[0038] The signal processing unit 4 performs frequency analysis of the radar data output from the radar unit 3, and calculates distance information and motion information regarding the object that reflected the transmission wave using the frequency analysis result. The signal processing unit 4 includes a frequency analysis unit 41, a distance calculation unit 42, and a speed calculation unit 43.

[0039] The frequency analysis unit 41 performs frequency analysis of a 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).

[0040] Specifically, the frequency analysis unit 41 performs a fast Fourier transform (FFT: abbreviation of Fast Fourier Transform) process on beat waveform data for a sampling time width (e.g., 100 milliseconds) per radar scan, specifically, on the amplitude of a difference signal (beat signal), to generate and output a frequency spectrum (beat frequency spectrum) that indicates the frequency distribution of the amplitude of the difference signal. The frequency spectrum indicates the amplitude of each frequency component included in the difference signal.

[0041] 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. From the received intensity and beat frequency in the frequency spectrum, the relative distance and relative speed of the object that reflected the transmitted wave can be calculated as distance and motion information about the object.

[0042] 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.

[0043] There are known methods for calculating distance based on the 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.

[0044] 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.

[0045] There are known methods for calculating the relative speed based on the frequency spectrum, and the present invention is not limited to a specific method, so detailed explanations will be omitted here. For example, the relative speed 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 relatively to each other, the frequency of the radio waves (i.e., the received waves) reflected by the surface of the object and received by the receiving antenna is affected by the relative speed of the radio waves with respect to the frequency of the radio waves (i.e., the transmitted waves) transmitted from the transmitting antenna when reflected by the surface of the object, and shifts according to the relative speed between the radar unit 3 and the object due to the Doppler effect.

[0046] The signal processing unit 4 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 an object, and the reception intensity I which is the absolute value of the amplitude for each frequency bin, which are 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".

[0047] 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 reception strength I values ​​for each combination of the same distance R value and relative velocity V value is used as the reception strength I value for that combination of distance R value and relative velocity V value.

[0048] 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, every time a radar scan is performed, a set of VR data (V, R, I) related to the radar scan is generated and output.

[0049] An example of VR data (V, R, I) is shown in Fig. 3(A). In Fig. 3(A), the horizontal axis is the relative velocity V and the vertical axis is the distance R, and the reception strength corresponding to the combination of (V, R) is shown. The value of degree I is displayed in different colors according to the magnitude of the value.

[0050] Here, the VR data (V, R, I) includes a speed component that corresponds to (in other words, is equivalent to) the moving speed of the moving speed detection device 1 itself, which is caused by reflected waves from surrounding stationary objects (for example, the ground / road surface, structures, and 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 own device with respect to the stationary target.

[0051] The reception intensity integrator 5 calculates an integrated reception intensity 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).

[0052] The reception strength integrating unit 5 uses a set of VR data (V, R, I) to integrate the value of reception strength I for each value of relative speed V to calculate an integrated reception strength value Is for each value of relative speed V. The integrated reception strength value Is is, in other words, an integrated value of reception strength I in the direction of distance R for each value of relative speed V in a VR plane as shown in Fig. 3, which is configured by a set of VR data (V, R, I). Note that the reception strength integrating unit 5 may, as necessary, divide the value of relative speed V into a predetermined range and integrate the value of reception strength I for each speed rank (in other words, speed bin).

[0053] 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 shows relative velocity V, and the vertical axis shows integrated reception intensity value Is.

[0054] 3B, peak A is a peak related to the reception strength of the reflected wave from an object near the radar unit 3 (particularly the transmitting antenna and the receiving antenna), for example, the reflected wave from a part of the vehicle structure. In this case, the object is moving together with the radar unit 3, so the value of the relative velocity V is 0, and therefore the peak appears at the position where the value of the relative velocity V on the horizontal axis is 0.

[0055] On the other hand, peak B is a peak related to the reception strength of the reflected wave from a stationary target, and is a peak related to the reception strength corresponding to the own movement speed of the moving speed detection device 1. When the moving speed detection device 1 and a surrounding object are moving relatively closer to each other, the peak related to the reception strength corresponding to the own movement speed of the moving speed detection device 1 appears in a region where the value of the relative speed V is negative (it can also be made to appear in a positive region depending on the calculation formula used).

[0056] From the above, in order to determine the relative speed of the device with respect to a stationary target, it is necessary to exclude the received strength of reflected waves from objects / structures in the vicinity of the radar unit 3 that are moving together with the radar unit 3.

[0057] In addition, the stationary targets that are the reference for calculating the relative speed of the own device are not distributed over the entire range of the distance R calculated in the processing of step S3. For this reason, if the value of the reception strength I is integrated for each value of the relative speed V for the entire range of the distance R calculated in the processing of step S3 for a set of VR data (V, R, I), a problem occurs in that a large amount of noise is integrated, resulting in a small S / N ratio (Signal-to-Noise ratio).

[0058] Therefore, in this invention, when calculating the reception intensity integrated value Is, the value of the reception intensity 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 when calculating the reception intensity integrated value Is is called the "intensity integrated distance range."

[0059] Specifically, when calculating the received intensity integrated value Is, the directivity of the transmitting / receiving antennas 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. a) Excluding the range in which there is an object that 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 becomes zero. a) Excluding the range where it is clear that there is an object moving relative to the ground / land. For example, when the moving speed detection device 1 is mounted on a railway and estimates the traveling speed of the railway, the range where other railways run (e.g., the range of adjacent tracks) is excluded, or when the moving speed detection device 1 is mounted on an automobile and estimates the traveling speed of the automobile, the range where other automobiles run (e.g., the range of adjacent lanes) is excluded. c) Excluding ranges where there are no stationary targets or where the received strength of the reflected waves is extremely weak even if a stationary target is present.

[0060] As the intensity accumulation distance range, only a lower limit may be set for the range of distance R (i.e., only the values ​​of reception intensity I of VR data where the value of distance R is equal to or greater than a predetermined value are accumulated), only an upper limit may be set (i.e., only the values ​​of reception intensity I of VR data where the value of distance R is equal to or less than a predetermined value are accumulated), or both a lower limit and an upper limit may be set (i.e., only the values ​​of reception intensity I of VR data where the value of distance R is equal to or greater than a predetermined value and equal to or less than a predetermined value are accumulated).

[0061] 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 integration 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 12 m and the upper limit is set to 30 m, just as an example.

[0062] In the example shown in FIG. 4(B), there is no peak (peak A in FIG. 3(B)) in the reception strength of the reflected wave from an object near the radar unit 3 (particularly the transmitting antenna and the receiving antenna), but peak B (see also FIG. 3(B)) in the reception strength of the reflected wave from a stationary target appears. In other words, the influence of objects near the radar unit 3 is eliminated and the S / N ratio of the stationary target is increased, so that the relative speed of the device itself can be accurately calculated, and ultimately the moving speed of the moving speed detection device 1 itself can be accurately estimated.

[0063] The reception intensity integrator 5 sets an intensity integrated distance range for the VR data (V, R, I), integrates the value of the reception intensity I for each value of the relative speed V using only the VR data (V, R, I) whose value of the distance R falls within the intensity integrated distance range, and outputs a set of data (V, Is) consisting of a combination of the relative speed V and the reception intensity integrated value Is. The data (V, Is) output from the reception intensity integrator 5 is called "reception intensity integrated value data."

[0064] The moving speed estimating unit 6 estimates the moving speed of the moving speed detecting device 1 itself by using the set of reception intensity integrated value data (V, Is) output from the reception intensity integrating unit 5 (step S6).

[0065] 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 value 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.

[0066] Here, the value Vm of the relative speed V to be identified as the moving speed of the moving speed detection device 1 itself is the relative speed with respect to surrounding stationary objects that reflect the transmitted wave (for example, structures or equipment fixedly installed on the ground / land; that is, stationary targets). However, in an environment where a stationary target cannot be detected, or an environment where a stationary target can be detected but the reception strength is below the noise level, a speed at which the stationary target does not actually exist, in other words, a speed corresponding to a reflected wave not from a stationary target, may be erroneously detected as the moving speed of the moving speed detection device 1 itself.

[0067] Therefore, in this embodiment, a reliability determination unit 7 is provided as a mechanism for suppressing the influence on the estimated value of the moving speed when the value of the relative speed V corresponding to a reflected wave not from a stationary target is erroneously detected as the moving speed of the moving speed detection device 1 itself.

[0068] The reliability determination unit 7 determines the reliability of the value Vm of the relative speed V output from the moving speed estimation unit 6 as the moving speed of the moving speed detection device 1 itself, and determines how to handle the value Vm of the relative speed V. The reliability determination unit 7 includes a reliability calculation unit 71, a reliability evaluation unit 72, and a hold determination unit 73.

[0069] The reliability calculation unit 71 calculates a speed reliability I as an index for evaluating the reliability of the value Vm of the relative speed V as the moving speed of the moving speed detection device 1 itself. R is calculated (step S7).

[0070] Specifically, the reliability calculation unit 71 calculates the speed reliability I based on the distribution of the reception intensity integrated value Is for each value of the relative speed V by the following formula 1. R In Equation 1, Ismax is the maximum value of the integrated reception strength value Is, that is, the value of the integrated reception strength value Is combined with the value Vm of the relative speed V in the set of integrated reception strength value data (V, Is), and Isavg is the average value of the integrated reception strength values ​​Is excluding Ismax (see FIG. 5). (Number 1) IR = 20 × log 10 (Ismax / Isavg)

[0071] When calculating the average value Isavg of the integrated reception intensity Is, in addition to the maximum value Ismax of the integrated reception intensity Is, the values ​​of the integrated reception intensity Is corresponding to the value of the relative speed V near the value Vm of the relative speed V corresponding to the maximum value Ismax may also be excluded. For example, when the value of the integrated reception intensity Is is integrated for each speed bin, the values ​​of the integrated reception intensity Is of the speed bins on both sides of the speed bin corresponding to the maximum value Ismax of the integrated reception intensity Is may also be excluded, or the values ​​of the integrated reception intensity Is of the speed bins on both sides of the speed bin corresponding to the maximum value Ismax of the integrated reception intensity Is may also be excluded.

[0072] The reliability evaluation unit 72 evaluates the speed reliability I calculated by the reliability calculation unit 71. R Based on this, the reliability of the value Vm of the relative speed V output from the moving speed estimating unit 6 as the moving speed of the moving speed detecting device 1 itself is evaluated (step S8).

[0073] Specifically, speed reliability I R The value of is the confidence threshold T R If it is greater than the value Vm of the relative speed V output from the moving speed estimation unit 6 (step S8: Yes), the reliability evaluation unit 72 outputs the value Vm of the relative speed V output from the moving speed estimation unit 6 as the moving speed of the moving speed detection device 1 itself, and sets the value Vm of the relative speed V as the hold relative speed value Vm. H (specifically, for example, stored in the ROM 23, etc.), and sets the value of the hold count C to 0 (step S9). After that, the reliability evaluation unit 72 returns the processing procedure for detecting the moving speed to the processing of step S1.

[0074] On the other hand, speed reliability I R The value of is the confidence threshold T R In the following cases (step S8: No), the reliability evaluation unit 72 calculates the hold relative velocity value V HThe detection device 1 outputs the moving speed as the moving speed of the detection device 1 itself, and adds 1 to the value of the hold count C (step S10).

[0075] In other words, speed reliability I R The value of is the confidence threshold T R In the following cases (step S8: No), the value Vm of the relative velocity V estimated based on the set of VR data (V, R, I) generated from the radar data acquired by the radar scan in question (step S1) and output from the movement speed estimation unit 6 is not output as the movement speed of the movement speed detection device 1 itself, but the value of the movement speed of the movement speed detection device 1 itself in the previous processing is held (i.e., the value of the movement speed of the movement speed detection device 1 itself is not updated).

[0076] Confidence threshold T R [dB] is not limited to a specific value, but is appropriately set to an appropriate value taking into consideration the characteristics related to the output of the radar unit 3 and whether the radar data is received in a good condition with no (or few) disturbances and the like, and therefore the peak of the reception intensity corresponding to an object reflecting the transmission wave can be accurately represented, or whether the radar data is received in a condition that cannot be considered good due to disturbances and so the peak of the reception intensity corresponding to an object reflecting the transmission wave cannot be accurately represented. R Specifically, [dB] may be set to an appropriate value within the range of about 2 to 8 [dB], for example, as one example only.

[0077] The hold determination unit 73 determines whether or not to continue holding the value of the moving speed of the moving speed detection device 1 itself, based on the value of the hold count C (step S11).

[0078] Specifically, the value of the hold count C is equal to or smaller than the hold threshold T C If it is equal to (step S11: Yes), the hold determination unit 73 sets the speed reliability I R The value of is the confidence threshold T RIn the following cases, the hold state of the moving speed value is released, and the value Vm of the relative speed V estimated based on the set of VR data (V, R, I) in the radar scan in question (step S1) and output from the moving speed estimation unit 6 is set as the hold relative speed value V H and sets the value of the hold count C to 0 (step S12). After that, the hold judging unit 73 returns the processing procedure for detecting the moving speed to the processing of step S1.

[0079] On the other hand, the value of the hold count C is the hold threshold T C If it is not equal to (step S11: No), the hold determination unit 73 returns the process of detecting the moving speed to the process of step S1. As a result, the moving speed of the moving speed detection device 1 itself is not updated for a predetermined period of time.

[0080] Hold Threshold T C is not limited to a specific value, but is set to an appropriate value taking into consideration the sampling time width per radar scan, and the prevention of a situation in which an abnormal relative velocity V value is held continuously due to an occurrence of speed hijacking, etc.

[0081] According to the above-mentioned moving speed detection device 1 and moving speed detection method, the moving speed of the radar device (radar unit 3) itself can be estimated based on radar data, so that by installing a radar device, it becomes possible to know the moving speed of various equipment, devices, vehicles, facilities, etc., from only the reception data of one receiving antenna system. According to the above-mentioned moving speed detection device 1 and moving speed detection method, in particular, the moving speed of the device itself is estimated using the reception intensity integrated value Is for each value of the relative speed V calculated using only data in which the value of the distance R falls within the intensity integrated distance range, so that it is possible to prevent erroneous estimation and more accurately estimate the moving speed of the device itself in various environments.

[0082] According to the above-described moving speed detection device 1 and moving speed detection method, and also by the processing by the reliability determination unit 7 (i.e., the processing of steps S7 to S12), it is possible to prevent the output of abnormal values ​​of the estimated moving speed when the reception strength is significantly reduced due to disturbances, etc., and it is possible to avoid sudden fluctuations in the estimated value of the moving speed and maintain the continuity of the estimated value of the moving speed, which in turn makes it possible to suppress the influence of a short-term reduction in reception strength on the estimated value of the moving speed, thereby improving the reliability of the technology for estimating the moving speed.

[0083] Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above embodiment, and even if there are design changes and the like within the scope of the gist of the present invention, they are included in the present invention.

[0084] 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 of the present invention, and any radar method may be used as long as it is capable of generating 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 those in the above embodiment.

[0085] Furthermore, in the above embodiment, the reliability determination unit 7 is provided to determine the reliability of the value Vm of the relative speed V as the moving speed of the moving speed detection device 1 itself; however, the processing by the reliability determination unit 7 (i.e., the processing of steps S7 to S12) is not an essential configuration for this invention, and the moving speed detection device 1 may have the value Vm of the relative speed V identified by the moving speed estimation unit 6 (step S6) and output as the moving speed of the moving speed detection device 1 itself.

[0086] In the above embodiment, the speed reliability I R [dB] is calculated, but the speed reliability I RThe calculation method is not limited to Equation 1. Specifically, for example, common logarithms may not be taken for the maximum value Ismax or the average value Isavg of the integrated reception intensity value Is.

[0087] Also, speed reliability I R The value of is the confidence threshold T R In the following case (step S8: No), in addition to the above embodiment, the reliability evaluation unit 72 calculates the hold relative velocity value V according to the following formula 2 as the process of step S10. H and the value of relative velocity V, Vm, are used as the velocity reliability I R The weighting factor W is determined according to the value of H and Wm weighted average value V N may be output as the moving speed of the moving speed detection device 1 itself (note that, in the process of step S10, the value of the hold count C is further incremented by 1) (see FIG. 6). (Number 2) V N = (W H ×V H +Wm × Vm) / (W H +Wm)

[0088] In this case, the moving speed detection device 1 calculates the speed reliability I based on the relationship between the maximum value Ismax of the integrated reception strength value Is and the average value Isavg of the integrated reception strength value Is excluding at least the maximum value Ismax. R The reliability determination unit 7 further calculates the speed reliability I R The weighting factor W is determined according to the value of H , Wm is used to calculate the past moving speed (specifically, the hold relative speed value V H ) and the most recent moving speed value (specifically, the relative speed V value Vm) N is output as the moving speed of the own device.

[0089] The value of the hold relative velocity in formula 2, V H Weighting factor W H is the relative velocity value for the hold V H The speed reliability I for the value Vm of the relative speed V stored asR The weighting coefficient Wm applied to the value Vm of the relative speed V is determined according to the speed reliability I R In this case, the speed reliability I R and the weighting factor W H Regarding the relationship between the value of Wm and the speed reliability I R The larger the value of the weighting factor W H ,Wm is larger, for example, the speed reliability I R The weighting coefficient W H , Wm is determined in advance as a function for calculating the values ​​of Wm. [Explanation of symbols]

[0090] 1. Movement speed detection device 2. Control section 21 Central Processing Unit 22 ROM 23 RAM 3. Radar Section 31 Transmitter 32 Receiving section 4. Signal Processing Section 41 Frequency analysis section 42 Distance calculation section 43 Speed ​​calculation section 5. Reception strength integrator 6 Moving speed estimator 7. Reliability judgment section 71 Reliability Calculation Unit 72 Reliability Evaluation Unit 73 Hold Judgment Section

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 strength integrating unit that integrates the reception strength for each value of the relative speed by using only the combination data in which the distance value is within a predetermined range, and calculates an integrated reception strength value for each value of the relative speed; a moving speed estimating unit that identifies a value of the relative speed corresponding to a maximum value of the integrated reception strength value; a reliability determination unit that calculates a speed reliability based on a relationship between the maximum value of the integrated reception strength value and an average value of the integrated reception strength value excluding at least the maximum value, outputting the determined value of the relative speed as a moving speed of the own device; a weighted average of a past value of the moving speed and a latest value of the moving speed using a weight determined according to the value of the speed reliability, and outputting the weighted average as the moving speed of the own device; A moving speed detection device characterized by:

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

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

3. A process of performing frequency analysis of radar data output from a radar device that emits a transmission wave and receives a reflected wave of the transmission wave that is reflected by an object, generating a frequency spectrum, and calculating a distance and a relative speed to the object to generate combined data of the distance, the relative speed, and the reception intensity in the frequency spectrum; A process of integrating the reception strength for each value of the relative speed by using only the combination data in which the distance value is within a predetermined range, and calculating an integrated reception strength value for each value of the relative speed; A process of identifying a value of the relative velocity corresponding to a maximum value of the integrated reception intensity value; and calculating a speed reliability based on a relationship between the maximum value of the integrated reception strength value and an average value of the integrated reception strength value excluding at least the maximum value, The specified value of the relative speed is set as a moving speed of the own device, a value calculated by weighting the past moving speed value and the latest moving speed value using a weight determined according to the value of the speed reliability, the value being set as the moving speed of the own device; A method for detecting a moving speed.

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

4. The method for detecting a moving speed according to claim 3.

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