Device and method for detecting moving speed

Abstract

To resolve ambiguity in speed measurement.SOLUTION: A signal processing unit 5, for combination data (V, R, I) of distance R between a transmission and reception unit 3 and an object obtained through the latest chirp frame processing, relative moving speed V of the transmission and reception unit 3 and the object, and reception intensity I, calculates a reception intensity integrated value Is obtained by integrating the value of the reception intensity I for every value of the relative moving speed V, calculates speed reliability IR on the basis of the relationship between the reception intensity integrated value Is combined with the value of observation relative speed Vo obtained through the latest chirp frame processing and the average value Isavg of the reception intensity integrated values Is excluding at least the reception intensity integrated value Is combined with the value of the observation relative speed Vo in the set of the combination data (V, Is), and outputs, as estimated relative speed Ve, a value VN calculated by performing weighted average of the value of the past estimated relative speed Ve and the value of the latest estimated relative speed Ve by using a weight determined according to the value of the speed reliability IR.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 relative movement speed between a radar device and an object 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 the object. [Background technology]

[0002] A known radar device for measuring distance and speed is a millimeter wave radar device that determines distance and speed from the frequency of a beat signal between a transmission signal and a reception signal of a continuous wave radar that has been frequency-modulated with a triangular wave (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-51055 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the reciprocal of the chirp time (in other words, the chirp period) of an FMCW (Frequency Modulated Continuous Wave) radar divided by 2 corresponds to the sampling frequency of Doppler (= relative velocity). According to the sampling theorem, frequencies above the Nyquist frequency cannot be restored by Fourier transform, so when the actual relative moving velocity between the radar device and an object increases, aliased signals appear at the velocity. For this reason, aliasing at the frequency corresponding to the velocity creates the problem of ambiguity in velocity measurement.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a moving speed detection device and a moving speed detection method that can eliminate ambiguity in speed measurement. [Means for solving the problem]

[0006] In order to solve the above problem, a moving speed detection device according to the present invention comprises a transceiver that emits a transmitted wave while alternately switching between two types of chirp times in odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave of the transmitted wave that is reflected by an object; and a signal processor that compares a set of velocity candidates generated based on the observed relative speed obtained by processing the odd-numbered chirp frames and the chirp time of the odd-numbered chirp frames, taking into account velocity aliasing, with a set of velocity candidates generated based on the observed relative speed obtained by processing the even-numbered chirp frames and the chirp time of the even-numbered chirp frames, and outputs an estimated relative speed based on a matching value, wherein the least common multiple of the aliased speed based on the chirp time of the odd-numbered chirp frames and the aliased speed based on the chirp time of the even-numbered chirp frames is equal to the relative speed between the transceiver and the object. the signal processing unit integrates the reception strength value for each value of the relative movement speed for combined data of the distance between the transmitter / receiver and the object, the relative movement speed between the transmitter / receiver and the object, and reception strength obtained by processing the latest chirp frame, to calculate an integrated reception strength value for each value of the relative movement speed, thereby generating a set of combined data of the relative movement speed and the integrated reception strength value, calculates a speed reliability based on the relationship between the integrated reception strength value combined with the value of the observed relative velocity obtained by processing the latest chirp frame in the set of combined data and an average value of the integrated reception strength values ​​excluding at least the integrated reception strength value combined with the value of the observed relative velocity, and outputs a value calculated by taking a weighted average of the value of the past estimated relative velocity and the value of the latest estimated relative velocity using a weight determined according to the value of the speed reliability as the estimated relative velocity.

[0007] The moving speed detection device according to the present invention may be configured such that the signal processing unit compares a set of velocity candidates generated in consideration of velocity folding back based on the values ​​of observed relative speeds identified by processing a plurality of the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames with a set of velocity candidates generated in consideration of velocity folding back based on the values ​​of observed relative speeds identified by processing a plurality of the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, and outputs an estimated relative speed based on the matching value.

[0008] A method of detecting a moving speed according to the present invention includes a process in which a transceiver unit emits a transmitted wave while alternately switching between two types of chirp time between odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave of the transmitted wave reflected by an object; a process in which a set of velocity candidates generated based on the observed relative velocity obtained by processing the odd-numbered chirp frame and the chirp time of the odd-numbered chirp frame, taking velocity aliasing into account, is compared with a set of velocity candidates generated based on the observed relative velocity obtained by processing the even-numbered chirp frame and the chirp time of the even-numbered chirp frame, taking velocity aliasing into account, and outputs an estimated relative speed based on a matching value; and a process in which, for combined data of the distance between the transceiver unit and the object, the relative moving speed between the transceiver unit and the object, and reception strength obtained by processing the latest chirp frame, a value of reception strength is calculated for each value of the relative moving speed. and calculating a reception intensity integrated value for each value of the relative moving speed to generate a set of combined data of the relative moving speed and the reception intensity integrated value; and calculating a speed reliability based on a relationship between the reception intensity integrated value combined with the value of the observed relative speed obtained by processing the latest chirp frame in the set of combined data and an average value of the reception intensity integrated values ​​excluding the reception intensity integrated value combined with at least the value of the observed relative speed, wherein the least common multiple of the turn-around speed based on the chirp time of the odd-numbered chirp frame and the turn-around speed based on the chirp time of the even-numbered chirp frame is equal to or greater than a maximum value that is actually assumed to be possible as the relative moving speed between the transmitter-receiver and the object, and a value calculated by taking a weighted average of the past estimated relative speed value and the latest estimated relative speed value using a weight determined according to the value of the speed reliability is output as the estimated relative speed.

[0009] The method for detecting a moving speed according to the present invention may compare a set of velocity candidates generated based on the values ​​of the observed relative speeds determined by processing a plurality of the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames, taking into account speed folding back, with a set of velocity candidates generated based on the values ​​of the observed relative speeds determined by processing a plurality of the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, taking into account speed folding back, and output an estimated relative speed based on the matching value. [Effects of the Invention]

[0010] According to the moving speed detection device and moving speed detection method of the present invention, a set of velocity candidates generated taking into account velocity aliasing based on the observed relative velocities obtained by processing odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames is compared with a set of velocity candidates generated taking into account velocity aliasing based on the observed relative velocities obtained by processing even-numbered chirp frames and the chirp times of the even-numbered chirp frames, and an estimated relative speed is output based on the matching value, thereby making it possible to eliminate ambiguity in speed measurement.

[0011] According to the moving speed detection device and moving speed detection method of the present invention, the least common multiple of the return speed based on the chirp time of odd-numbered chirp frames and the return speed based on the chirp time of even-numbered chirp frames is equal to or greater than the maximum value that is actually assumed to be possible as the relative moving speed between the transmitter / receiver and the object, thereby making it possible to reliably eliminate ambiguity in speed measurement.

[0012] The moving speed detection device and moving speed detection method of the present invention compare a set of speed candidates based on observed relative speed values ​​identified by processing multiple odd-numbered chirp frames with a set of speed candidates based on observed relative speed values ​​identified by processing multiple even-numbered chirp frames, and output an estimated relative speed based on the matching value. This makes it possible to prevent the output of abnormal estimated relative speed values, and ultimately improves the reliability of the moving speed estimation technology.

[0013] The moving speed detection device and moving speed detection method of the present invention, when configured to output as an estimated relative speed a value calculated by taking a weighted average of past estimated relative speed values ​​and the latest estimated relative speed values ​​using a weight determined according to a speed reliability value calculated using a reception strength integrated value calculated by integrating reception strength values ​​for each relative moving speed value, make it possible to prevent the output of abnormal estimated relative speed values ​​estimated when reception strength has significantly decreased due to disturbances, etc., while outputting a value weighted by the respective reliability of past estimated relative speed values ​​and the latest estimated relative speed values.In turn, it becomes possible to suppress the effect on the estimated relative speed value of a short-term decrease in reception strength, thereby improving the reliability of the moving speed estimation technology. [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] FIG. 10 is a diagram illustrating switching of modulation settings for each chirp frame in an embodiment. [Figure 3] FIG. 10 is a diagram illustrating an example of velocity folding in a set of VR data. [Figure 4] 2 is a diagram illustrating a method for estimating speed in a speed correction unit of the moving speed detection device of FIG. 1. FIG. [Figure 5] 1. FIG. 4 is a diagram illustrating another method for estimating speed in the speed correction unit of the moving speed detection device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described below based on the illustrated embodiments.

[0016] 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.

[0017] The moving speed detection device 1 is a mechanism for estimating the relative moving speed between the radar device and an object based on radar data acquired by the radar, and mainly comprises a control unit 2, a transceiver unit 3, an A / D conversion unit 4, and a signal processing unit 5.

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

[0019] The control unit 2 uses the RAM as a working area as needed by the central processing unit to execute a program for controlling the operation of the movement speed detection device 1, which is stored in the ROM, 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 of this embodiment includes a transceiver 3 that emits a transmitted wave while alternately switching between two types of chirp times Tca and Tcb between odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave that is the transmitted wave reflected back from an object; and a signal processor 5 that compares a set of velocity candidates generated based on the observed relative velocity Vo obtained by processing the odd-numbered chirp frames and the chirp time Tca of the odd-numbered chirp frames, taking into account velocity aliasing, with a set of velocity candidates generated based on the observed relative velocity Vo obtained by processing the even-numbered chirp frames and the chirp time Tcb of the even-numbered chirp frames, taking into account velocity aliasing, and outputs an estimated relative velocity Ve based on the matching value, and is configured so that the least common multiple of the aliasing velocity Vmaxa based on the chirp time Tca of the odd-numbered chirp frames and the aliasing velocity Vmaxb based on the chirp time Tcb of the even-numbered chirp frames is greater than or equal to the maximum value that is actually assumed to be the relative moving speed between the transceiver 3 and the object (see Figure 1).

[0021] In addition, the method for detecting the moving speed of this embodiment includes a process in which the transceiver 3 emits a transmitted wave while alternately switching between two types of chirp times Tca and Tcb between odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave of the transmitted wave reflected by an object; and a process in which a set of velocity candidates is generated taking into account velocity aliasing based on the observed relative velocity Vo obtained by processing the odd-numbered chirp frames and the chirp time Tca of the odd-numbered chirp frames, and a set of velocity candidates is generated taking into account velocity aliasing based on the observed relative velocity Vo obtained by processing the even-numbered chirp frames and the chirp time Tcb of the even-numbered chirp frames, and an estimated relative velocity Ve is output based on the matching value, and the least common multiple of the aliasing velocity Vmaxa based on the chirp time Tca of the odd-numbered chirp frames and the aliasing velocity Vmaxb based on the chirp time Tcb of the even-numbered chirp frames is greater than or equal to the maximum value that is actually assumed to be the relative moving speed between the transceiver 3 and the object.

[0022] The transmitter / receiver 3 includes a voltage generating circuit 31, a voltage controlled oscillator 32, a distribution circuit 33, a transmitting antenna , a receiving antenna 35, and a mixer .

[0023] The transmitter / receiver 3 generates radio waves (also called "millimeter waves") having a frequency of, for example, the 79 GHz band, 76 GHz band, or 60 GHz band, and radiates / transmits the radio waves into the surrounding space via the transmitting antenna 34. In the present invention, it is preferable to use radio waves in a high frequency band.

[0024] The transmitter / receiver 3 outputs radar data acquired by performing a radar scan using, for example, an FMCW (Frequency Modulated Continuous Wave) radar system.

[0025] 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 is reflected off the surface of an 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, specifically by performing frequency analysis in the distance direction, to calculate the distance between the transmitter / receiver 3 and the object that reflected the transmitted wave.Furthermore, the relative moving speed between the transmitter / receiver 3 and the object that reflected the transmitted wave is calculated by measuring and analyzing the phase of the frequency of the calculated distance for each continuous wave, specifically by performing frequency analysis in the speed direction.

[0026] FMCW radar is a continuous wave radar that modulates frequency over time, generating and transmitting a burst wave containing multiple chirps. Each waveform, or chirp, contained in the burst wave is generated by sweeping the frequency over time, so that the frequency changes linearly (specifically, rises or falls) over time.

[0027] Multiple chirps are emitted / 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 processing is performed for each chirp frame.

[0028] In this invention, two different chirp times (i.e., one chirp repetition period) are used, and transmission and reception are performed by alternately switching between the two different chirp times every chirp frame (see FIG. 2).

[0029] In this embodiment, the odd-numbered (i.e., 1st, 3rd, 5th, ...) chirp frames use "modulation pattern A" as the modulation setting, and the even-numbered (i.e., 2nd, 4th, 6th, ...) chirp frames use "modulation pattern B" as the modulation setting. The odd-numbered (i.e., 1st, 3rd, 5th, ...) chirp frames are called "odd frames", and the even-numbered (i.e., 2nd, 4th, 6th, ...) chirp frames are called "even frames".

[0030] The modulation settings include, for example, chirp time Tc, chirp frame time Tf (or chirp number), and chirp frequency (i.e., modulation frequency) range f1-f2. In this invention, the chirp time Tca of modulation pattern A and the chirp time Tcb of modulation pattern B are set to different values ​​(i.e., Tca ≠ Tcb) so that at least the aliasing speed Vmaxa of modulation pattern A and the aliasing speed Vmaxb of modulation pattern B are different predetermined values. Note that the chirp frame times Tfa and Tfb and the chirp frequency ranges f1a-f2a and f1b-f2b of the two modulation patterns A and B may be set to different values ​​or may be set to the same value.

[0031] Although the aliasing speed Vmaxa of modulation pattern A and the aliasing speed Vmaxb of modulation pattern B are not limited to a specific combination of values, they are adjusted and set so that the least common multiple of Vmaxa and Vmaxb is equal to or greater than the maximum value that is actually assumed to be the relative moving speed between the transceiver 3 and the object that reflects the transmitted wave.

[0032] Both the aliasing speed Vmaxa of modulation pattern A and the aliasing speed Vmaxb of modulation pattern B may be set to be smaller than the maximum value that is actually assumed to be possible as the relative movement speed between the transceiver 3 and the object that reflects the transmitted wave. In other words, it does not matter if aliasing of the speed occurs in both the transmission and reception process using modulation pattern A and the transmission and reception process using modulation pattern B. By narrowing the range of detectable relative speeds, it is possible to avoid a decrease in the resolution of the relative speed.

[0033] In this embodiment, as an example, the range of relative movement speeds between the transceiver 3 and an object that reflects the transmitted wave that is assumed to be actually possible is from −400 km / h to +400 km / h. In this embodiment, the aliasing speed Vmaxa of modulation pattern A is set to 100 km / h (i.e., the detectable range of relative speeds is from −100 km / h to +100 km / h), and the aliasing speed Vmaxb of modulation pattern B is set to 80 km / h (i.e., the detectable range of relative speeds is from −80 km / h to +80 km / h). Therefore, the least common multiple of the aliasing speed Vmaxa of modulation pattern A and the aliasing speed Vmaxb of modulation pattern B is 400, which is greater than or equal to the maximum value of the relative movement speed between the transceiver 3 and an object that reflects the transmitted wave that is assumed to be actually possible.

[0034] The voltage generating circuit 31 generates a modulation voltage in which a waveform changes in a triangular wave shape, with successive alternating sections where the level gradually increases and sections where the level gradually decreases on the time axis, and outputs the generated modulation voltage as a control voltage. Note that an FCM (short for Fast Chirp Modulation) method may be used as the radar method, and a modulation voltage that changes in a sawtooth wave shape may be generated and output as a control voltage.

[0035] In this case, the voltage generation circuit 31 alternately switches between two different modulation periods (corresponding to chirp times) for each chirp frame to generate a modulation voltage and output it as a control voltage. In this embodiment, a modulation voltage that changes according to modulation pattern A is generated in odd-numbered frames and output as a control voltage, and a modulation voltage that changes according to modulation pattern B is generated in even-numbered frames and output as a control voltage.

[0036] The generation of the modulation voltage by the voltage generation circuit 31 is controlled by the control unit 2. That is, the control unit 2 controls the voltage generation circuit 31 so that the modulation setting is switched between modulation settings according to modulation pattern A and modulation pattern B for each chirp frame to generate the modulation voltage and output it as a control voltage.

[0037] The voltage controlled oscillator 32 receives the control voltage output from the voltage generating circuit 31 as an input, and 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 alternately in accordance with the control voltage, with one waveform (in other words, one chirp) changing in a triangular wave shape. Note that an FCM method may be used as the radar method, and a transmission signal in which the frequency changes in a sawtooth wave shape may be generated and output.

[0038] In this embodiment, the voltage-controlled oscillator 32 generates and outputs a transmission signal that is frequency-modulated according to modulation pattern A in odd-numbered frames, and generates and outputs a transmission signal that is frequency-modulated according to modulation pattern B in even-numbered frames.

[0039] The distribution circuit 33 receives the transmission signal output from the voltage controlled oscillator 32, distributes the transmission signal to a transmission antenna 34 and a mixer 36 at a predetermined distribution ratio, and supplies the distributed signal.

[0040] If necessary, an amplifier circuit for amplifying the transmission signal may be provided between the distribution circuit 33 and the transmission antenna 34 .

[0041] The transmitting antenna 34 receives the transmission signal supplied from the distribution circuit 33, generates a transmission wave based on the transmission signal, and radiates / transmits the transmission wave into the surrounding space.

[0042] The receiving antenna 35 captures / receives radio waves, including radio waves (i.e., transmitted waves) emitted from the transmitting antenna 34 that are reflected off the surface of an object (in other words, a target) in the surrounding space and return (i.e., reflected waves; also called "Doppler reflected waves"), and outputs a signal corresponding to the reflected waves as a received signal.

[0043] The mixer 36 receives the transmission signal (also called the "local signal") supplied from the distribution circuit 33, and also receives the reception signal output from the reception antenna 35, mixes the transmission signal with the reception signal, and generates and outputs a differential signal (an analog signal).

[0044] Between the mixer 36 and the A / D conversion unit 4, an amplifier circuit for amplifying the differential signal, a filter circuit for suppressing unnecessary frequency components in the differential signal, and the like may be provided as needed.

[0045] The A / D conversion unit 4 receives the differential signal output from the transmission / reception unit 3, performs sampling processing (in other words, analog-to-digital conversion processing) on ​​the analog differential signal using a predetermined sampling frequency, converts the differential signal into digital data, and outputs the digitized differential signal (specifically, digital voltage data).

[0046] Here, the same sampling frequency is used for processing odd-numbered frames and even-numbered frames in the A / D conversion unit 4. That is, since the chirp time Tca of modulation pattern A and the chirp time Tcb of modulation pattern B are set to mutually different values ​​(i.e., Tca ≠ Tcb), the same sampling frequency is used for processing chirp frames according to modulation pattern A and modulation pattern B, and therefore the aliasing speed Vmaxa of modulation pattern A and the aliasing speed Vmaxb of modulation pattern B become mutually different values.

[0047] The differential signal as radar data output from the transmitter / receiver 3 after a radar scan is a signal having a frequency component that is the deviation between the frequency component of the transmission signal (local signal) distributed from the transmitting side via the distribution circuit 33 and the frequency component of the reception signal output from the reception antenna (i.e., a signal having a beat frequency, also called a "beat signal").

[0048] Every time a radar scan is performed, radar data is output from the transmitting / receiving unit 3 and input to the signal processing unit 5 via the A / D conversion unit 4.

[0049] The signal processing unit 5 performs frequency analysis of the differential signal as radar data output from the transmitting / receiving unit 3 and converted into digital data by the A / D conversion unit 4, and calculates distance information and motion information about the object that reflected the transmitted wave using the frequency analysis results. The signal processing unit 5 includes a distance frequency analysis unit 51, a velocity frequency analysis unit 52, a velocity detection unit 53, and a velocity correction unit 54.

[0050] The distance frequency analysis unit 51 performs frequency analysis in the distance direction on the differential signal (beat signal) as radar data (in other words, beat waveform data) output from the A / D conversion unit 4.

[0051] Specifically, the distance frequency analysis unit 51 performs frequency analysis processing in the distance direction using a fast Fourier transform (FFT: abbreviation for Fast Fourier Transform) on the amplitude of the differential signal (beat signal), which is the beat waveform data for one radar scan, and outputs a frequency complex spectrum in which discrete frequencies correspond to distance.

[0052] The velocity frequency analysis unit 52 performs frequency analysis in the velocity direction on the differential signal (beat signal) as radar data (beat waveform data).

[0053] Specifically, the velocity frequency analysis unit 52 receives as input the frequency complex spectrum in which the discrete frequencies output from the distance frequency analysis unit 51 correspond to distance, performs frequency analysis processing in the velocity direction using fast Fourier transform on each part of the frequency complex spectrum in which the discrete frequencies correspond to the same distance, and outputs a power spectrum in which the discrete frequencies correspond to velocity, that is, a two-dimensional frequency power spectrum that ultimately corresponds to the distance direction and the velocity direction, as a result of the two-dimensional fast Fourier transform processing in the distance direction and the velocity direction.

[0054] The velocity detection unit 53 receives the two-dimensional frequency power spectrum corresponding to the distance direction and the velocity direction output from the velocity frequency analysis unit 52, detects a portion of the two-dimensional frequency power spectrum where the signal strength / received strength is greater than a predetermined detection threshold and is a maximum as a peak, and identifies a discrete frequency in the distance direction (i.e., a discrete frequency corresponding to the distance) and a discrete frequency in the velocity direction (i.e., a discrete frequency corresponding to the velocity) corresponding to the peak. Note that when a discrete frequency transform such as a fast Fourier transform is performed, the frequencies in the distance direction and the velocity direction corresponding to the peak can be obtained as discrete frequencies.

[0055] The detection threshold is not limited to a specific value, but is set to an appropriate value as appropriate, taking into consideration that the peak of the two-dimensional frequency power spectrum can be appropriately detected, etc. The detection threshold may be determined in advance, or may be set using a dynamic threshold algorithm, CFAR (Constant False Alarm Rate).

[0056] The velocity detection unit 53 further uses the discrete frequencies in the distance direction and the discrete frequencies in the velocity direction corresponding to the peaks in the two-dimensional frequency power spectrum identified above to calculate and output, based on the principles of FMCW radar, the distance between the transmitter / receiver 3 and the object that reflected the transmitted wave (referred to as the "observed distance Ro") and the relative moving speed between the transmitter / receiver 3 and the object (specifically, the instantaneous relative speed when the transmitted wave is reflected by the surface of the object; referred to as the "observed relative speed Vo").

[0057] The signal processing unit 5 performs processing for each radar scan. That is, the observed relative velocity Vo is calculated each time a radar scan is performed.

[0058] The moving speed detection device 1 may be mounted on a vehicle such as a train or an automobile. In this case, the differential signal as radar data output from the transmitter / receiver 3 includes a velocity component corresponding to (in other words, 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, or equipment fixedly installed on the ground / land; referred to as "stationary targets"). Therefore, by focusing on the reflected waves from the stationary targets, it is possible to estimate the moving speed of the moving speed detection device 1 itself. In other words, it is possible to estimate the moving speed of the moving speed detection device 1 itself by calculating the relative speed of the device itself with the stationary targets as a reference, and ultimately it is possible to estimate the moving speed / traveling speed of the vehicle.

[0059] When the moving speed detection device 1 is mounted on a vehicle and estimates the moving speed of the moving speed detection device 1 itself, the signal strength / receiving strength values ​​may be integrated for each speed direction value (in other words, for each frequency bin / speed bin) for the two-dimensional frequency power spectrum corresponding to the distance direction and the speed direction output from the speed frequency analysis unit 52 to calculate an integrated receiving strength value for each speed direction value, and the maximum value of the integrated receiving strength values ​​may be identified, and the speed direction value corresponding to the maximum value may be output as the observed relative speed Vo. In this case, the observed relative speed Vo is the moving speed of the moving speed detection device 1 itself. Note that the integrated receiving strength value is, in other words, the integrated receiving strength value in the distance direction for each speed direction value (in other words, for each frequency bin / speed bin) in the two-dimensional frequency power spectrum.

[0060] When the moving speed detection device 1 is mounted on a vehicle and estimates the moving speed of the moving speed detection device 1 itself, the range of distance direction values ​​(in other words, frequency bins / distance bins) in the two-dimensional frequency power spectrum used for calculation processing related to the detection of the moving speed may be limited, taking into consideration the following items A to C. a) Excluding the range in which there is an object that exists in the vicinity of the transmitter / receiver 3 and moves together with the transmitter / receiver 3, so that the value of the relative moving speed with respect to the transmitter / receiver 3 becomes 0. A) Excluding areas where it is clear that there are moving objects (i.e., objects that are not stationary targets) 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, 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 mounted 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). c) Excluding 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.

[0061] In digital signal processing using digital voltage data as described above, frequency analysis is performed using a discrete Fourier transform, which causes frequency aliasing based on the sampling theorem. Specifically, the range of relative velocity that can be detected is determined by the chirp time Tc, and when the actual relative velocity between the transmitter / receiver 3 and the object that reflected the transmitted wave exceeds this range, velocity aliasing occurs. The range of relative velocity that can be detected in frequency analysis using a discrete Fourier transform is called the "relative velocity detection range."

[0062] Fig. 3 shows an example of the speed folding in a set of data (called "VR data (V, R, I)") consisting of a combination of the relative moving speed V (unit: km / h) between the transmitter / receiver 3 and the object that reflected the transmitted wave, the distance R (unit: m) between the transmitter / receiver 3 and the object, and the reception strength I, based on the two-dimensional frequency power spectrum corresponding to the distance direction and the speed direction output from the speed frequency analysis unit 52. In Fig. 3, the horizontal axis represents the relative moving speed V and the vertical axis represents the distance R, and the value of the reception strength I corresponding to the combination of (V, R) is expressed as The color changes depending on the size of the

[0063] Figure 3 shows an example in which the return speed Vmax is 100 km / h (i.e., the relative speed detection range is from -100 km / h to +100 km / h) and the actual relative movement speed between the transmitter / receiver 3 and the object that reflected the transmitted wave (called the "actual relative speed Va") is 120 km / h.Since the actual relative speed Va exceeds the relative speed detection range by 20 km / h, an alias signal appears at the return speed of -80 km / h.

[0064] Therefore, in this invention, modulation pattern A is used as the modulation setting for odd-numbered frames and modulation pattern B is used as the modulation setting for even-numbered frames, so that two different chirp times Tca and Tcb are alternately switched for each chirp frame for transmission and reception.The Nyquist frequency changes for each chirp frame, and the relative velocity detection range in the signal processing unit 5 changes for each chirp frame.This changes the velocity that folds back during one chirp frame, and the relative velocity is estimated by utilizing this.

[0065] For example, the actual relative velocity Va is estimated using the (n)th chirp frame and the (n+1)th chirp frame (where n is a natural number) (see Figure 4). In the example shown in Figure 4, the (n)th chirp frame is an odd-numbered frame, and the (n+1)th chirp frame is an even-numbered frame.

[0066] In the example shown in Figure 4, the range of possible relative movement speeds between the transmitter / receiver 3 and the object that reflects the transmitted wave is assumed to be from -400 km / h to +400 km / h, and the actual relative speed Va is assumed to be 120 km / h.

[0067] The velocity correction unit 54 receives the observed relative velocity Vo output from the velocity detection unit 53 after processing the [n]th chirp frame, and generates a set of velocity candidates within a range that is assumed to be actually possible as the relative movement velocity between the transmitter / receiver 3 and the object that reflects the transmitted wave, based on the value of the observed relative velocity Vo and the aliasing velocity Vmaxa of modulation pattern A, which is the modulation setting for odd frames.

[0068] In the example shown in Figure 4, when the [n]th chirp frame is processed and the value of the observed relative velocity Vo output from the velocity detection unit 53 is -80, the return velocity Vmaxa of modulation pattern A, which is the modulation setting for odd frames, is 100 km / h, so the velocity correction unit 54 generates a set of velocity candidates including -280, -80, 120, and 320 [km / h].

[0069] The velocity correction unit 54 also receives the observed relative velocity Vo output from the velocity detection unit 53 after processing the (n+1)th chirp frame, and generates a set of velocity candidates within the range that is assumed to be actually possible relative movement velocities between the transmitter / receiver 3 and an object that reflects the transmitted wave, based on the value of the observed relative velocity Vo and the aliasing velocity Vmaxb of modulation pattern B, which is the modulation setting for even frames.

[0070] In the example shown in Figure 4, when the (n+1)th chirp frame is processed and the value of the observed relative velocity Vo output from the velocity detection unit 53 is -40, the return velocity Vmaxb of modulation pattern B, which is the modulation setting for the even frame, is 80 km / h, so the velocity correction unit 54 generates a set of velocity candidates including -360, -200, -40, 120, and 280 [km / h].

[0071] The velocity correction unit 54 then compares the set of velocity candidates generated for the [n]th chirp frame with the set of velocity candidates generated for the [n+1]th chirp frame to identify matching values, and outputs the matching values ​​as an estimate of the relative movement velocity between the transmitter / receiver 3 and the object that reflected the transmitted wave (referred to as the "estimated relative velocity Ve").

[0072] In the example shown in FIG. 4, the speed corrector 54 identifies 120 as a matching value from the set of speed candidates, and outputs 120 [km / h] as the estimated relative speed Ve.

[0073] When comparing sets of speed candidates to identify matching values, a predetermined range for the speed candidate values ​​may be set, and if the absolute value of the difference between the speed candidate values ​​included in each set of speed candidate is within the predetermined range, the two speed candidate values ​​may be determined to match. For example, if the absolute value of the difference between the speed candidate values ​​is 0.5 km / h or less, the two speed candidate values ​​may be determined to match. In this case, the value obtained by the most recent calculation process of the two speed candidate values ​​determined to match may be output as the estimated relative speed Ve, or the average value of the two speed candidate values ​​determined to match may be output as the estimated relative speed Ve.

[0074] (When multiple odd and multiple even frames are used) To reduce the occurrence of erroneous estimation, the estimated relative velocity Ve may be calculated (i.e., the actual relative velocity Va) using a plurality of odd-numbered frames and a plurality of even-numbered frames (see FIG. 5).

[0075] In the example shown in Fig. 5, the [n]th to [n+3]th chirp frames are used to calculate the estimated relative velocity Ve (i.e., estimate the actual relative velocity Va), where n is a natural number. In the example shown in Fig. 5, the [n]th and [n+2]th chirp frames are odd-numbered frames, and the [n+1]th and [n+3]th chirp frames are even-numbered frames. The modulation settings and other conditions are assumed to be the same as those in the example shown in Fig. 4.

[0076] In the example shown in FIG. 5 , the velocity correction unit 54 receives the observed relative velocity Vo for each chirp frame output from the velocity detection unit 53 after processing the [n]th through [n+3]th chirp frames, and compares the value of the observed relative velocity Vo for the [n]th chirp frame with the value of the observed relative velocity Vo for the [n+2]th chirp frame, i.e., the values ​​of the observed relative velocity Vo for each odd-numbered frame, and also compares the value of the observed relative velocity Vo for the [n+1]th chirp frame with the value of the observed relative velocity Vo for the [n+3]th chirp frame, i.e., the values ​​of the observed relative velocity Vo for each even-numbered frame.

[0077] Next, if the absolute value of the difference between the values ​​of the observed relative velocity Vo for each odd frame is within a predetermined range, the velocity correction unit 54 determines that the values ​​of the observed relative velocity Vo in the processing of multiple odd frames are (approximately) equal and therefore that the observation has been performed appropriately, and identifies the value obtained in the most recent calculation process among the values ​​of the observed relative velocity Vo for each odd frame as the observed relative velocity Vo for the multiple odd frames, or identifies the average value of the values ​​of the observed relative velocity Vo for the multiple odd frames as the observed relative velocity Vo for the multiple odd frames.

[0078] Furthermore, if the absolute value of the difference between the values ​​of the observed relative velocity Vo for each even frame is within a predetermined range, the velocity correction unit 54 determines that the values ​​of the observed relative velocity Vo in the processing of multiple even frames are (approximately) equal and therefore that the observation has been performed appropriately, and identifies the value obtained in the most recent calculation process among the values ​​of the observed relative velocity Vo for each even frame as the observed relative velocity Vo for the multiple even frames, or identifies the average value of the values ​​of the observed relative velocity Vo for each even frame as the observed relative velocity Vo for the multiple even frames.

[0079] Note that when multiple odd-numbered frames and multiple even-numbered frames are used, it is possible that the relative movement speed between the transmitter / receiver 3 and the object may change between frames. For this reason, for example, when it is expected that the relative speed will change significantly and it is important to grasp the latest accurate relative speed, it is possible to specify the value obtained by the latest calculation process among the values ​​of the observed relative speed Vo for each odd-numbered / even-numbered frame as the observed relative speed Vo for the multiple odd-numbered / even-numbered frames. Also, when it is expected that the relative speed will not change significantly and it is important to grasp a stable relative speed, it is possible to specify the average value of the values ​​of the observed relative speed Vo for each odd-numbered / even-numbered frame as the observed relative speed Vo for the multiple odd-numbered / even-numbered frames.

[0080] The velocity correction unit 54 then generates a set of velocity candidates within a range that is assumed to be actually possible relative movement velocities between the transmitter / receiver 3 and an object that reflects the transmitted wave, based on the values ​​of the observed relative velocity Vo of the multiple odd-numbered frames identified by the above processing and the aliasing velocity Vmaxa of modulation pattern A, which is the modulation setting of the odd-numbered frames.

[0081] The velocity correction unit 54 also generates a set of velocity candidates within a range that is assumed to be actually possible relative movement velocities between the transmitter / receiver 3 and an object that reflects the transmitted wave, based on the values ​​of the observed relative velocity Vo of the multiple even frames identified by the above processing and the aliasing velocity Vmaxb of modulation pattern B, which is the modulation setting for the even frames.

[0082] The velocity correction unit 54 then compares the set of velocity candidates generated for the multiple odd-numbered frames with the set of velocity candidates generated for the multiple even-numbered frames to identify matching values ​​and outputs the matching values ​​as the estimated relative velocity Ve.

[0083] When comparing sets of speed candidates to identify matching values, a predetermined range for the speed candidate values ​​may be set, and if the absolute value of the difference between the speed candidate values ​​included in each set of speed candidate is within the predetermined range, the two speed candidate values ​​may be determined to match. For example, if the absolute value of the difference between the speed candidate values ​​is 0.5 km / h or less, the two speed candidate values ​​may be determined to match. In this case, the value obtained by the most recent calculation process of the two speed candidate values ​​determined to match may be output as the estimated relative speed Ve, or the average value of the two speed candidate values ​​determined to match may be output as the estimated relative speed Ve.

[0084] In the example shown in Figure 5, which explains the case where multiple odd-numbered frames and multiple even-numbered frames are used to calculate the estimated relative velocity Ve (i.e., estimate the actual relative velocity Va), a total of four chirp frames, [n] to [n+3], are used, but the total number of chirp frames may be five or more.

[0085] That is, when a plurality of odd-numbered frames and a plurality of even-numbered frames are used to calculate the estimated relative velocity Ve (i.e., to estimate the actual relative velocity Va), the values ​​of the observed relative velocity Vo for each odd-numbered frame may be compared to identify the observed relative velocity Vo for each odd-numbered frame, and the values ​​of the observed relative velocity Vo for each even-numbered frame may be compared to identify the observed relative velocity Vo for each even-numbered frame, and the set of velocity candidates generated for the odd-numbered frames may be compared with the set of velocity candidates generated for the even-numbered frames, and the matching value may be output as the estimated relative velocity Ve.

[0086] (When the reliability of the estimated relative velocity Ve is taken into consideration) In order to reduce the occurrence of erroneous estimation, the reliability of the estimated relative velocity Ve (in other words, the reliability of the observed relative velocity Vo) may be taken into consideration when calculating the estimated relative velocity Ve (i.e., estimating the actual relative velocity Va).

[0087] In this case, the speed correction unit 54 calculates the speed reliability I according to the following formula 1. R Calculate [dB]. (Number 1) I R = 20 × log 10 (Ismax / Isavg)

[0088] According to the above formula 1, the speed reliability I R To calculate [dB], for a set of VR data (V, R, I) based on the two-dimensional frequency power spectrum corresponding to the distance direction and the speed direction obtained by processing the latest chirp frame, the value of the reception intensity I is integrated for each value of the relative movement speed V to calculate an integrated reception intensity value Is for each value of the relative movement speed V, and a set of combined data (V, Is) of the relative movement speed V and the integrated reception intensity value Is is generated. The integrated reception intensity value Is is, in other words, the integrated value of the reception intensity I in the direction of distance R for each value of the relative movement speed V in the set of VR data (V, R, I).

[0089] In addition, in the above formula 1, Ismax is the value of the integrated reception intensity value Is combined with the value of the observed relative velocity Vo in the set of combined data (V, Is) of the relative moving velocity V and the integrated reception intensity value Is. Also, Isavg is the average value of the integrated reception intensity value Is excluding Ismax in the set of combined data (V, Is) of the relative moving velocity V and the integrated reception intensity value Is.

[0090] When calculating the average value Isavg of the integrated reception intensity values ​​Is, in addition to Ismax, values ​​of the integrated reception intensity values ​​Is combined with values ​​of relative movement speed V near the value of the observed relative speed Vo in the set of combination data (V, Is) of relative movement speed V and integrated reception intensity values ​​Is may also be excluded. For example, values ​​of the integrated reception intensity values ​​Is combined with values ​​of relative movement speed V on both sides of the value of the observed relative speed Vo may also be excluded, or values ​​of the integrated reception intensity values ​​Is combined with values ​​of relative movement speed V on both sides of the value of the observed relative speed Vo may also be excluded.

[0091] And speed reliability I R If the value of is greater than a predetermined reliability threshold, the velocity correction unit 54 outputs the value of the estimated relative velocity Ve obtained by the calculation process including the processing of the latest chirp frame, and stores the value of the estimated relative velocity Ve as a hold relative velocity Vh (specifically, for example, in a ROM or the like).

[0092] On the other hand, speed reliability I R If the value of the velocity reliability I is equal to or less than the reliability threshold, the velocity correction unit 54 outputs the value of the hold relative velocity Vh. R If the value of is equal to or less than the reliability threshold, the value of the estimated relative velocity Ve obtained in the latest calculation process is not output, but the value of the estimated relative velocity Ve obtained in the previous calculation process is held, and the value of the estimated relative velocity Ve is not updated.

[0093] The reliability threshold [dB] is not limited to a specific value, but is set to an appropriate value taking into consideration the characteristics of the output of the transmitter / receiver 3 and whether the radar data is received in good conditions with no (or little) disturbance and therefore can accurately show peaks in the reception intensity corresponding to objects that have reflected the transmission waves, or whether the radar data is received in less than good conditions due to disturbances and therefore cannot accurately show peaks in the reception intensity corresponding to objects that have reflected the transmission waves.

[0094] Furthermore, when the value of the estimated relative velocity Ve is held, if the held state of the value of the estimated relative velocity Ve continues for a period of time equal to or longer than a predetermined hold threshold, the held state of the value of the estimated relative velocity Ve is released, and the value of the estimated relative velocity Ve obtained by calculation processing including processing of the latest chirp frame is output, and the value of the estimated relative velocity Ve is stored as a hold relative velocity Vh (specifically, for example, stored in a ROM, etc.).

[0095] The hold threshold 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 need to prevent the abnormal estimated relative velocity Ve value from being held continuously due to speed hijacking or the like.

[0096] In addition, speed reliability I R The method of calculating is not limited to the above-mentioned formula 1, and for example, common logarithms may not be taken for Ismax and Isavg.

[0097] Also, speed reliability I R If the value of is equal to or less than the reliability threshold, the velocity correction unit 54 calculates the hold relative velocity Vh and the value of the estimated relative velocity Ve obtained by the calculation process including the processing of the latest chirp frame according to the following formula 2, as a velocity reliability I R The weighted average value V is determined by the weighting coefficients Wh and We, which are determined according to the value of N may be output. (Number 2) V N = (Wh×Vh+We×Ve) / (Wh+We)

[0098] In the above formula 2, the weighting coefficient Wh applied to the value Vh of the hold relative speed is the speed reliability I R The weighting coefficient We applied to the estimated relative speed Ve is determined according to the speed reliability I R In this case, the speed reliability I R Regarding the relationship between the value of and the weighting coefficients Wh and Wm, basically, the speed reliability I R The larger the value of , the larger the value of the weighting coefficients Wh and Wm. Specifically, for example, the speed reliability I R is determined in advance as a function for calculating the values ​​of the weighting coefficients Wh and Wm using the values ​​of

[0099] According to the moving speed detection device 1 and the moving speed detection method described above, a set of velocity candidates is generated taking into account velocity aliasing based on the observed relative velocity Vo obtained by processing odd frames and the chirp time Tca of the odd frames, and a set of velocity candidates is generated taking into account velocity aliasing based on the observed relative velocity Vo obtained by processing even frames and the chirp time Tcb of the even frames, and an estimated relative velocity Ve is output based on the matching value, thereby making it possible to eliminate ambiguity in velocity measurement.

[0100] According to the moving speed detection device 1 and the moving speed detection method as described above, the least common multiple of the aliasing speed Vmaxa of modulation pattern A, which is the modulation setting for odd frames, and the aliasing speed Vmaxb of modulation pattern B, which is the modulation setting for even frames, is set to be equal to or greater than the maximum value that is actually assumed to be possible as the relative moving speed between the transmitter / receiver 3 and the object that reflects the transmitted wave, so it is possible to reliably eliminate ambiguity in measuring the speed.

[0101] Furthermore, according to the moving speed detection device 1 and the moving speed detection method described above, when a set of speed candidates based on the values ​​of the observed relative speed Vo identified by processing a plurality of odd-numbered frames is compared with a set of speed candidates based on the values ​​of the observed relative speed Vo identified by processing a plurality of even-numbered frames and an estimated relative speed Ve is output based on the matching value, it becomes possible to prevent the output of an abnormal value of the estimated relative speed Ve, and ultimately to improve the reliability of the moving speed estimation technology.

[0102] According to the above-described moving speed detection device 1 and moving speed detection method, the speed reliability I is calculated according to the above-described formula 1 using the reception strength integrated value Is calculated by integrating the value of the reception strength I for each value of the relative moving speed V. RIf the value of the estimated relative velocity Ve is not updated for a predetermined period of time depending on the value of I, it becomes possible to prevent the output of an abnormal value of the estimated relative velocity Ve when the reception strength I drops significantly due to disturbances, etc., and ultimately to suppress the effect on the value of the estimated relative velocity Ve caused by a short-term drop in reception strength I, thereby improving the reliability of the technology for estimating moving velocity.

[0103] According to the above-described moving speed detection device 1 and moving speed detection method, the speed reliability I is calculated according to the above-described formula 1 using the reception strength integrated value Is calculated by integrating the value of the reception strength I for each value of the relative moving speed V. R The value V is calculated by taking a weighted average of the past estimated relative velocity Ve and the latest estimated relative velocity Ve according to the above formula 2 using weights Wh and We determined according to the value of N As the estimated relative velocity, if the above equation is set to be output, it becomes possible to prevent the output of an abnormal value of the estimated relative velocity Ve that is estimated when the reception strength I drops significantly due to disturbances or the like, while outputting a value that is a weighted average of the past value of the estimated relative velocity Ve and the latest value of the estimated relative velocity Ve, each calculated based on the reliability of each value. In turn, it becomes possible to suppress the effect of a short-term drop in reception strength I on the value of the estimated relative velocity Ve, thereby improving the reliability of the technology for estimating the moving velocity.

[0104] 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. [Explanation of symbols]

[0105] 1. Moving speed detection device 2. Control section 3 Transmitter / Receiver 31 Voltage generation circuit 32 Voltage Controlled Oscillator 33 Distribution circuit 34 transmitting antenna 35 receiving antenna 36 Mixer 4 A / D conversion section 5. Signal Processing Section 51 Distance frequency analysis unit 52 Speed ​​frequency analysis section 53 Speed ​​detection unit 54 Speed ​​correction section

Claims

1. a transceiver that emits a transmission wave while alternately switching between two types of chirp time in odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave that is the transmission wave reflected by an object and returns; a signal processing unit that compares a set of velocity candidates generated based on the observed relative velocities obtained by processing the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames, taking velocity aliasing into consideration, with a set of velocity candidates generated based on the observed relative velocities obtained by processing the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, and outputs an estimated relative velocity based on matching values; the least common multiple of the turnover speed based on the chirp time of the odd-numbered chirp frame and the turnover speed based on the chirp time of the even-numbered chirp frame is equal to or greater than the maximum value that is actually assumed to be possible as the relative moving speed between the transceiver and the object; The signal processing unit For combined data of the distance between the transmitter / receiver and the object, the relative moving speed between the transmitter / receiver and the object, and the receiving strength obtained by processing the latest chirp frame, the value of the receiving strength is integrated for each value of the relative moving speed to calculate an integrated receiving strength value for each value of the relative moving speed, thereby generating a set of combined data of the relative moving speed and the integrated receiving strength value; Calculating a velocity reliability based on a relationship between the integrated reception intensity value combined with the value of the observed relative velocity obtained by processing the latest chirp frame in the set of combined data and an average value of the integrated reception intensity values ​​excluding at least the integrated reception intensity value combined with the value of the observed relative velocity; a weighted average of the past estimated relative speed values ​​and the latest estimated relative speed value using a weight determined according to the speed reliability value, and outputting the calculated value as the estimated relative speed; A moving speed detection device characterized by:

2. The signal processing unit a set of velocity candidates generated in consideration of velocity aliasing based on the observed relative velocity values ​​identified by processing a plurality of the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames, and a set of velocity candidates generated in consideration of velocity aliasing based on the observed relative velocity values ​​identified by processing a plurality of the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, and an estimated relative velocity is output based on the matching values; 2. The moving speed detection device according to claim 1.

3. A process in which the transmitter / receiver radiates a transmission wave while alternately switching between two types of chirp time in odd-numbered chirp frames and even-numbered chirp frames, and receives a reflected wave that is the transmission wave reflected by an object and returns; a process of comparing a set of velocity candidates generated based on the observed relative velocities obtained by processing the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames, taking velocity aliasing into consideration, with a set of velocity candidates generated based on the observed relative velocities obtained by processing the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, taking velocity aliasing into consideration, and outputting an estimated relative velocity based on the matching values; a process of integrating the value of reception strength for each value of relative movement speed for combination data of the distance between the transmitter / receiver and the object, the relative movement speed between the transmitter / receiver and the object, and reception strength obtained by processing the latest chirp frame, to calculate an integrated reception strength value for each value of relative movement speed, and generating a set of combination data of the relative movement speed and the integrated reception strength value; and calculating a velocity reliability based on a relationship between the integrated reception intensity value combined with the value of the observed relative velocity obtained by processing the latest chirp frame in the set of combined data and an average value of the integrated reception intensity values ​​excluding at least the integrated reception intensity value combined with the value of the observed relative velocity, the least common multiple of the turnover speed based on the chirp time of the odd-numbered chirp frame and the turnover speed based on the chirp time of the even-numbered chirp frame is equal to or greater than the maximum value that is actually assumed to be possible as the relative moving speed between the transceiver and the object; a weighted average of the past estimated relative speed values ​​and the latest estimated relative speed value using a weight determined according to the speed reliability value, and outputting the calculated value as the estimated relative speed; A method for detecting a moving speed.

4. a set of velocity candidates generated in consideration of velocity aliasing based on the observed relative velocity values ​​identified by processing a plurality of the odd-numbered chirp frames and the chirp times of the odd-numbered chirp frames, and a set of velocity candidates generated in consideration of velocity aliasing based on the observed relative velocity values ​​identified by processing a plurality of the even-numbered chirp frames and the chirp times of the even-numbered chirp frames, and an estimated relative velocity is output based on the matching values; 4. The method for detecting a moving speed according to claim 3.

Images