JP2012026791A - Radar device, position/speed detection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar device, position/speed detection method, and program in which it can be determined whether or not an object separated in a long distance symmetrically returns a half frequency of a sampling frequency without increase of costs of the device, and positional information based on the return by the object separated in a long distance can be appropriately excluded in accordance with the environment.SOLUTION: A radar device includes: transmitters (3, 4, 9, 10) for transmitting modulation waves of the same sweep bandwidth and modulation frequencies different from each other as transmission signals; receivers (1-1 to 1-n) for receiving reflection signals from a target in response to the transmission signals transmitted by the transmitters; beat signal generators (2-1 to 2-n) for generating beat signals by mixing the transmission signals and reception signals received by the receivers; and a return target discrimination section 30 for discriminating whether or not the beat signal is a return target for the object separated in a long distance on the basis of a reception level of the beat signal, and excluding information based on the return target if the beat signal is the return target.

Description

  The present invention relates to a radar apparatus, a position / velocity detection method, and a program.

  2. Description of the Related Art In recent years, a detection device has been proposed that uses a millimeter wave radar to measure the position of a distant vehicle, the moving distance, and the distance between the vehicle and the vehicle based on the reflected signal of an object such as a vehicle ahead of the radar or a structure. . In this case, an FMCW (Frequency-Modulated Continuous Wave) method that can simultaneously acquire a distance and a relative velocity is known as a vertical direction detection unit, and a DBF (horizontal direction detection unit) is known as a horizontal direction detection unit. There are known methods such as orientation detection by the Digital Beam Forming method and object separation by the MUSIC (MUlitiple Signal Classification) method.

  In the FMCW method, a modulated wave is transmitted, a reflected wave of an object such as a vehicle ahead of a radar or a structure is received, and a beat signal is generated by mixing the transmission signal and the reception signal with a mixer. Then, the generated beat signal is converted into a digital signal by an A / D converter and is taken in, and a frequency component for a distant vehicle is extracted by performing FFT (Fast Fourier Transform) processing. The relative speed and distance of the distant vehicle are calculated based on the combination of the frequency components extracted in the increase section and the decrease section (see, for example, Patent Document 1).

Japanese Patent No. 3988571

  When the FMCW method is used, the radar apparatus receives a reflected signal from a vehicle far from the detection range and processes the received reflected signal, so that the object is actually located at a position where the vehicle does not exist. May be detected.

  FIG. 8 is a conceptual diagram for explaining detection using the FMCW method according to the prior art. An outline of the detection method in the case of the FMCW method using the first triangular wave and the second triangular wave having different modulation periods for the transmission signal will be described. The radar apparatus generates the first triangular wave W1 and the second triangular wave W2 having the same sweep bandwidth Δf and different only in the modulation frequency fm such as fm1 and fm2. Further, the radar apparatus FM-modulates the carrier wave with a modulation signal having a triangular wave waveform, and transmits a transmission wave having an increase section and a decrease section of the modulation frequency toward the object. Then, the radar apparatus receives the reflected wave that is transmitted and reflected by the object.

  In FIG. 8, the detection range of the first triangular wave is Rm_max, and the detection range of the second triangular wave is Rs_max. When the vehicle that is the detection object is located at R1 within the detection range of the first triangular wave and the second triangular wave, the radar apparatus is based on the reflected waves of the first triangular wave and the second triangular wave, and both at the same position R1. Detect.

  On the other hand, when the detection target is located at the relative distance R2, the radar apparatus detects at the distance R2 because the reflected wave of the first triangular wave is within the detection range. In this case, the radar device detects the object located at the distance R1 at the distance R2s because the reflected wave of the second triangular wave is outside the detection range Rs_max. As described above, since the positions of the reflected wave of the first triangular wave and the reflected wave of the second triangular wave do not coincide with each other, the radar apparatus can determine whether the signal is the return signal of the object within the detection range or the object at a long distance. .

  Further, when the object is located at the relative distance R3, the radar device exceeds the detection range for both the first triangular wave and the second triangular wave. Detects objects. Also in this case, as in the case of the distance R2, since the detection positions of the reflected wave of the first triangular wave and the reflected wave of the second triangular wave do not coincide with each other, the radar apparatus determines whether the object is a return signal of the object at a long distance. Can be determined.

  On the other hand, when the object is located at the relative distance R4, both the first triangular wave and the second triangular wave exceed the detection range, and thus the radar apparatus detects each return signal at the same distance R5. As described above, when the object is located at the relative distance R4, when both the first triangular wave and the second triangular wave exceed the detection range, the radar apparatus detects the object within the detection range and the object at a long distance. It is not possible to determine whether the signal is a return signal.

  As described above, in the prior art, it is determined whether or not the signal is a folding signal by comparing the positional relationship between the first triangular wave and the second triangular wave of the radar. For this reason, when a long-distance object is located outside the detection range, there is a problem in that it is not possible to determine whether the object is within the detection range or a long-distance object by using only the reflected waves. .

  Although it is conceivable to identify the above-mentioned problems with hardware, a high-order filter circuit or a high-speed A / D converter that performs oversampling is required, leading to an increase in the cost of the apparatus. is there.

  The present invention has been made in consideration of such circumstances, and its purpose is that a long-distance object folds back half the sampling frequency symmetrically without increasing the cost of the apparatus. To provide a radar apparatus, a position / velocity detection method, and a program that can determine whether or not there is, and can remove position information due to the return of an object at a long distance according to the environment. is there.

  In order to solve the above-described problem, a radar apparatus according to the present invention is a radar apparatus that detects a position or velocity of a target or a position and velocity of the target from a reflected signal from the target, and has the same sweep bandwidth. A transmitter that transmits modulated waves having different modulation frequencies as a transmission signal, a receiver that receives a reflected signal from the target with respect to the transmission signal transmitted by the transmitter, and a signal received by the transmission signal and the receiver. A beat signal generation unit that generates a beat signal by mixing the received signal, and whether or not the target is a return target of a long-distance object based on the reception level of the beat signal. A folding target determination unit that removes information based on the folding target in some cases, and To have.

  In the radar apparatus according to the present invention, the folding target determination unit may include a beat signal of the reception signal with respect to a transmission signal having a shorter period and a reception signal with respect to a transmission signal having a longer period of the transmission signal. Based on the reception level with the beat signal, it may be determined whether or not the target is a return target of a long-distance object. If the target is a return target, information based on the return target may be removed.

  Further, in the radar apparatus according to the present invention, the folding target determination unit is configured to detect a long distance based on a background noise level included in a beat signal of the reception signal with respect to one of the transmission signals. You may make it determine whether it is the determination of whether it is the said return target of a target object, and the removal of the information based on a return target.

  In order to solve the above-described problem, the position / velocity detection method according to the present invention is a position / velocity detection method for detecting the position or speed of the target or the position and speed of the target from a reflected signal from the target. A transmitting unit transmitting modulated waves having the same sweep bandwidth and different modulation frequencies as a transmission signal, a receiving unit receiving a reflected signal from the target with respect to the transmission signal, and a beat signal generation A unit that mixes the transmission signal and the reception signal received by the reception unit to generate a beat signal, and the folding target determination unit is configured to detect a long-distance object based on the reception level of the beat signal. It is determined whether or not it is a return target, and if it is a return target, information based on the return target is displayed. It is characterized in that it comprises the steps of to, a.

  In order to solve the above-described problem, the program according to the present invention can provide the same sweep band to the computer of the radar apparatus that detects the position or velocity of the target from the reflected signal from the target, or the position and velocity of the target. A transmission procedure for transmitting modulated signals having different widths and modulation frequencies as a transmission signal, a reception procedure for receiving a reflected signal from the target with respect to the transmission signal, and the transmission signal and the received reception signal are mixed. Based on the beat signal generation procedure for generating the beat signal and the reception level of the beat signal, it is determined whether or not the target is a return target of a long-distance object. And a return target determination procedure for removing information based thereon.

  According to the present invention, the presence or absence of a folding target can be determined, and the folding target can be appropriately removed according to the environment.

1 is a block diagram illustrating a configuration of a radar apparatus according to a first embodiment of the present invention. It is a conceptual diagram for demonstrating the transmission signal and reception signal by this 1st Embodiment. It is a conceptual diagram which shows the filter characteristic of the received wave (1st triangular wave, 2nd triangular wave) by this 1st Embodiment. It is a conceptual diagram which shows the example of a signal waveform detected by the filter characteristic of FIG. In this 1st Embodiment, it is a conceptual diagram for demonstrating whether a return | turnback target process is performed. In this 1st Embodiment, it is a conceptual diagram for demonstrating whether a return | turnback target process is performed according to the average of background noise. It is a flowchart for demonstrating operation | movement (turning back target determination logic) of the radar apparatus by this 1st Embodiment. It is a conceptual diagram for demonstrating the detection using the FMCW system by a prior art.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the radar apparatus according to the first embodiment. In FIG. 1, the radar apparatus according to the first embodiment includes receiving antennas 1-1 to 1-n, mixers 2-1 to 2-n, transmitting antenna 3, distributor 4, filters 5-1 to 5-n, SW (switch) 6, ADC (A / D converter) 7, control unit 8, triangular wave generation unit 9, VCO 10, and signal processing unit 20 are provided. The signal processing unit 20 includes a memory 21, a DBF processing unit 23, a peak detection unit 24, a peak combination unit 25, a distance detection unit 26, a speed detection unit 27, a pair determination unit 28, an azimuth detection unit 29, a turn target determination unit 30, And a target determination unit 31.

  Next, the operation of the radar apparatus according to the first embodiment will be described with reference to FIG. The radar apparatus of FIG. 1 is an electronic scanning type. The receiving antennas 1-1 to 1-n receive a reflected signal, that is, a received signal, which is transmitted from a target reflected from the target. The mixers 2-1 to 2-n mix the transmission signals transmitted from the transmission antenna 3 and the signals obtained by amplifying the reception signals received at the reception antennas 1-1 to 1-n by the amplifiers. The beat signal corresponding to each frequency difference is generated. The receiving units are the receiving antennas 1-1 to 1-n, and the beat signal generating units are the mixers 2-1 to 2-n.

  The transmission antenna 3 transmits a transmission signal obtained by frequency-modulating the triangular wave signal generated by the triangular wave generation unit 9 in a VCO (Voltage Controlled Oscillator) 10 as a transmission signal to the target. The distributor 4 distributes the frequency-modulated transmission signal from the VCO 10 to the mixers 2-1 to 2-n and the transmission antenna 3. The transmission unit includes a triangular wave generation unit 9, a VCO 10, a distributor 4, and a transmission antenna 3.

  The filters 5-1 to 5-n perform band limitation on the beat signals of Ch1 to Chn corresponding to the receiving antennas 1-1 to 1-n generated in the mixers 2-1 to 2-n, respectively. And a beat signal whose band is limited is output to the SW (switch) 6. In response to the sampling signal input from the control unit 8, the SW 6 outputs the beat signals of Ch1 to Chn corresponding to the receiving antennas 1-1 to 1-n that have passed through the filters 5-1 to 5-n. Are sequentially switched and output to an ADC (A / D converter) 7.

  The ADC 7 performs A / D conversion on the beat signals of Ch1 to Chn corresponding to each of the receiving antennas 1-1 to 1-n input from the SW6 in synchronization with the sampling signal in synchronization with the sampling signal. Then, it is converted into a digital signal and stored in the waveform storage area of the memory 21 in the signal processing unit 20 sequentially. The control unit 8 is configured by a microcomputer or the like, and controls the entire radar apparatus based on a control program stored in a ROM (not shown) or the like.

  The memory 21 stores the reception signal A / D converted by the ADC 7 in the waveform storage area as time-series data (ascending portion and descending portion) corresponding to each antenna 1-1 to 1-n. For example, when 256 pieces are sampled in each of the rising part (up) and the falling part (down) of the triangular wave, data of 2 × 256 × number of antennas is stored in the waveform storage area.

  A DBF (Digital Beam Forming) processing unit 23 converts data corresponding to each antenna 1-1 to 1-n from the sampled data of the beat signal stored in the memory 21 in the antenna arrangement direction. Fourier transform, that is, spatial axis Fourier transform. Further, the DBF processing unit 23 calculates spatial complex data for each angle channel that depends on the angle, that is, corresponds to the angular resolution, and the calculated spatial complex data for each angle channel and the peak detection unit 24 for each beat frequency. Output to the detection unit 29.

  For example, if each of the ascending part and the descending part has 256 sampled data for each antenna, it is converted into a beat frequency as complex frequency domain data for each antenna, and 128 pieces of data are obtained for each of the ascending part and the descending part. Complex data (2 × 128 × number of antenna data). The beat frequency is indicated by a frequency point.

  The peak detection unit 24 detects the peak value of the intensity of each of the rising and falling parts of the triangular wave of the beat frequency subjected to frequency conversion, and is preset from the peak in signal intensity (or amplitude, etc.) using complex number data. The presence of a target for each beat frequency is detected by detecting a beat frequency having a peak value exceeding the specified numerical value, and the peak combination unit 25 uses the beat frequency of the peak value (both ascending and descending portions) as the target frequency. Output to.

  Accordingly, the peak detector 24 converts the complex number data of any antenna or the sum of complex data of all antennas into a frequency spectrum, so that each peak value of the spectrum depends on the beat frequency, that is, the target depending on the distance. It can be detected as presence. By adding complex number data of all antennas, noise components are averaged, and the S / N ratio is improved.

  The peak combination unit 25 combines the beat frequencies and peak values of the ascending region and the descending region with respect to the beat frequency and the peak value input from the peak detection unit 24, for example, in a brute force manner in a matrix. That is, all the beat frequencies of the rising portion and the falling portion are combined and sequentially output to the distance detection unit 26 and the speed detection unit 27.

Next, the distance detection unit 26 calculates the distance r to the target from the numerical value obtained by adding the target frequency of the rising portion and the target frequency of the falling portion that are sequentially input from the peak combination unit 25. In addition, the distance detection unit 26 outputs the calculated distance r to the target to the pair determination unit 28.
Further, the speed detection unit 27 calculates the relative speed v of the target from the difference between the target frequency of the rising portion and the target frequency of the falling portion input from the peak combination unit 25. Further, the speed detection unit 27 outputs the calculated target relative speed v to the pair determination unit 28.

  The pair determination unit 28 generates a table based on the input distance r, relative speed v, and peak value levels pu and pd of descending and rising. The pair determination unit 28 determines an appropriate combination of the peaks of the rising part and the falling part corresponding to each target, determines a pair of peaks of the rising part and the falling part as a table, and determines the determined distance r, The target group number indicating the relative velocity v is output to the azimuth detecting unit 29. The pair confirmation unit 28 stores the distance, relative speed, and frequency point (ascending region or descending region, or ascending region and descending region) as a table in the internal storage unit of the pair confirming unit 28 corresponding to the target group number. is doing. Here, since the direction of each target group is not determined, the position in the horizontal direction parallel to the arrangement direction of the receiving antennas 1-1 to 1-n with respect to the vertical axis with respect to the arrangement direction of the antenna array in the radar apparatus. Has not been determined.

  Here, for example, the pair determination unit 28 prioritizes the value predicted in the current detection cycle from the distance r and the relative speed v with each target finally determined in the previous detection cycle. It is also possible to use a technique such as selecting a combination.

  The azimuth detecting unit 29 receives the spatial complex data for each angle channel calculated from the DBF processing unit 23 for each beat frequency, the distance r determined from the pair determining unit 28, and the target group number indicating the relative velocity v. Is done. The azimuth detecting unit 29 performs an AR spectrum estimation process of a high resolution algorithm, a spectrum estimation process using the MUSIC method, and the like, and an average of spectrum estimations obtained by averaging with the results of spectrum estimation performed in the past Based on the processing result, the direction of the corresponding target is detected. The azimuth detection unit 29 outputs the detected azimuth information, the target group, and the reception signal based on the first triangular wave and the reception signal based on the second triangular wave, which are beat signals, to the return target determination unit 30.

The return target determination unit 30 receives the azimuth information detected by the azimuth detection unit 29, the target group, and the reception signal based on the first triangular wave and the reception signal based on the second triangular wave, which are beat signals. The return target determination unit 30 determines the magnitude of the background noise of the received signal by the second triangular wave. The folded target determination unit 30 compares the received signal levels of the first triangular wave and the reflected wave of the second triangular wave when the background noise is equal to or lower than a predetermined threshold, and detects the object outside the detection range. It is determined whether it is a return.
The return target determination unit 30 determines whether there is a second triangular wave corresponding to a pair obtained from the received signal of the first triangular wave. When there is a second triangular wave reflected wave corresponding to the pair obtained from the first triangular wave received signal, the folding target determining unit 30 reflects the second triangular wave reflected wave corresponding to the pair obtained from the first triangular wave received signal. It is determined whether the signal level is lower than the reception signal level of the first triangular wave. When the signal level of the reflected wave of the second triangular wave corresponding to the pair obtained from the received signal of the first triangular wave is smaller than the received signal level of the first triangular wave, the folding target determination unit 30 is obtained from the received signal of the first triangular wave The target group number indicating the distance r and the relative velocity v in which the pair is determined is removed from the input target group. On the other hand, when the signal level of the reflected wave of the second triangular wave corresponding to the pair obtained from the received signal of the first triangular wave is larger than the received signal level of the first triangular wave, the pair determined distance r obtained from the first triangular wave received signal , And the target group number indicating the relative speed v is output to the target determination unit 31. That is, the information based on the return target is a target group number indicating a distance r and a relative velocity v in which a pair obtained from the first triangular wave reception signal is determined.

  The target determination unit 31 determines the distance between the target orientation and the target based on the distance r determined by the return target determination unit 30 and the target group number indicating the relative speed v.

  2A and 2B are conceptual diagrams for explaining a transmission signal and a reception signal according to the first embodiment. In the first embodiment, the first triangular wave and the second triangular wave used as transmission signals are frequency-modulated with a predetermined modulation width Δf by a triangular wave having a voltage amplitude, as shown in FIG. The broken line in the figure indicates a received signal. 2A, mixers 2-1 to 2-n transmit signals transmitted from the transmission antenna 3 and receptions received by the reception antennas 1-1 to 1-n. The beat signal corresponding to each frequency difference generated by mixing the signal with the signal amplified by the amplifier is shown. In the transmission signal, the rising part, the modulation frequency increasing section, or the section where the frequency called the upstream phase increases ("up" in the figure), the falling part, the modulation frequency decreasing section, or the frequency called the downstream phase decreases. Section ("down" in the figure). FIG. 2 (b) shows the signal levels of uplink and downlink.

  FIG. 3 is a conceptual diagram showing filter characteristics of received waves (first triangular wave and second triangular wave) according to the first embodiment. FIG. 4 is a conceptual diagram showing an example of a signal waveform detected by the filter characteristics of FIG. In FIG. 3, a curve indicated by a solid line indicates a change in detection level with respect to the detection distance of the first triangular wave, and a curve indicated by a broken line indicates a change in detection level with respect to the detection distance of the second triangular wave. In this way, the attenuation characteristics are different due to the different modulation periods of the first triangular wave and the second triangular wave.

  Therefore, as shown in FIG. 4, within the detection distance range A, the reception level from the target (distant vehicle) is greater than or equal to a predetermined threshold value for both the first triangular wave and the second triangular wave. On the other hand, outside the detection distance range B, the second triangular wave is below the threshold value because the amount of attenuation of the detection level is larger than that of the first triangular wave.

  Thus, since the reception level of the second triangular wave is smaller than the reception level of the first triangular wave outside the detection distance range B, the reception level of the first triangular wave and the reception level of the second triangular wave are compared. Thus, a received wave from a distant target can be detected as a return target and can be removed.

  FIG. 5 is a conceptual diagram for explaining whether or not the return target process is performed in the first embodiment. FIGS. 6A and 6B are conceptual diagrams for explaining whether or not the return target processing is performed according to the average of the background noise in the first embodiment. 6 (a) and 6 (b), the received signal for the second triangular wave is sampled at a predetermined sampling rate, and a predetermined average value of the previous noise level and a predetermined average value of the current noise level are respectively determined. The background noise level is calculated by weighting. As an example, weighting of n% (n is a natural number between 1 and 99) is performed on the average of the previous noise level, and weighting of 100% -n% is performed on the average value of the current noise level.

  In FIG. 5, when the folded target processing is not performed, the background noise level of the received signal of the second triangular wave is −A as shown in FIG. 6B in a multi-reflection environment where there are many structures around. This is a case of larger than (dB). Under such an environment, since the background noise is high, the folded ghost process is not performed. Note that the unit of background noise, which is a criterion for determination when the return target processing is not performed, may not be dB.

  On the other hand, in FIG. 5, when the folded target process is performed, the background noise level of the received signal of the second triangular wave is −A ( dB) The following cases. Under such an environment, since the background noise is low, the aliasing ghost process is performed.

  FIG. 7 is a flowchart for explaining the operation (turned target determination logic) of the radar apparatus according to the first embodiment. First, the first triangular wave and the second triangular wave are transmitted from the transmitting antenna 3, and the respective reflected waves are received by the receiving antennas 1-1 to 1-n, and the mixers 2-1 to 2-n and the filters 5-1 to 5-1. The reflected wave received by the ADC 7 is AD-sampled via the 5-n, SW (switch) 6 (step S1).

Next, the signal processing unit 20 performs signal processing of the AD signal sampled by AD sampling (step S2),
Next, the peak combination unit 25 creates a peak combination of the first triangular wave (step S3). At this time, the received signal is processed by being divided into an upstream period signal and a downstream period signal. For this reason, the rising part (increasing section) and the descending part (decreasing section) of the first triangular wave are combined.

  Next, the return target determination unit 30 determines whether or not the background noise of the received signal due to the second triangular wave is equal to or lower than a predetermined threshold (step S4). When the background noise of the received signal by the second triangular wave is equal to or smaller than the predetermined threshold (step S4; YES), the return target determination unit 30 confirms the distance of the second triangular wave corresponding to the first triangular wave combination. (Step S5), it is determined whether there is a peak corresponding to the combination of the first triangular wave, that is, whether the reception level of the first triangular wave is higher than the reception level of the second triangular wave (Step S6).

  When there is a peak corresponding to the combination of the first triangular wave, that is, when the reception signal level of the first triangular wave is higher than the reception signal level of the second triangular wave (YES in step S6), the return target determination unit 30 receives the reception signal. It is determined that the signal is a return target (step S7), and the process ends. In this case, the return target determination unit 30 removes the target group number indicating the distance r and the relative velocity v obtained from the first triangular wave received signal from the input target group, the distance r, and the relative The target group from which the target group number indicating the speed v is removed is output to the target determination unit 31.

  On the other hand, when the background noise of the received signal by the second triangular wave is larger than the predetermined threshold (step S4; NO), the return target determination unit 30 determines whether the return target or the real reflection from the target is described later. The process is terminated without determining whether it is a wave. Thus, before determining whether it is a return target or a real one, which will be described later, the background noise is determined, and if the background noise is large, the calculation efficiency can be improved by exiting the processing. it can.

  Further, when the background noise of the received signal by the second triangular wave is not more than a predetermined threshold and there is no peak corresponding to the combination of the first triangular wave, that is, the reception level of the first triangular wave is smaller than the reception level of the second triangular wave. If there is (step S6; NO), the return ghost determination unit 30 determines that the return ghost is not a return ghost, that is, a real reflected wave from the target (step S8), and ends the process. In this case, the return ghost determination unit 30 outputs the target group number indicating the pair-established distance r and the relative velocity v obtained from the first triangular wave reception signal to the target determination unit 31.

[Second Embodiment]
A second embodiment of the present invention will be described.
In the second embodiment, in the flowchart shown in FIG. 7 described above, the step of determining background noise in step S4 is performed after determining whether the target is a return target in steps S7 and S8. . Therefore, even if the reflected wave is determined to be genuine, the target group number indicating the distance r and the relative velocity v is determined by the folded target determination unit 30 if the background noise is determined to be greater than the predetermined threshold. Are removed from the input target group.

  According to the first and second embodiments described above, the received signal levels of the first triangular wave and the second triangular wave are different based on the filter characteristics according to the distance from the host vehicle to the distant vehicle. For this reason, by comparing the received signal levels of the first triangular wave and the second triangular wave, it can be determined whether or not it is a folded ghost, and the recognition performance of the radar can be improved.

  In addition, since it is determined whether or not the aliasing target is to be removed based on the background noise level, the aliasing target can be appropriately removed according to the environment, so that the radar recognition performance can be improved. Can do.

  In the first and second embodiments described above, the DBF processing unit 23, the peak detection unit 24, the peak combination unit 25, the distance detection unit 26, the speed detection unit 27, the pair determination unit 28, the azimuth detection unit 29, and the return target By recording a program for realizing each function in the determination unit 30, the target determination unit 31 and the like on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium, You may perform an encoding process and a decoding process. Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

1-1 to 1-n receiving antenna 2-1 to 2-n mixer 3 transmitting antenna 4 distributor 5-1 to 5-n filter 6 SW (switch)
7 ADC (A / D converter)
8 Control unit 9 Triangular wave generation unit 10 VCO
DESCRIPTION OF SYMBOLS 20 Signal processing part 21 Memory 23 DBF processing part 24 Peak detection part 25 Peak combination part 26 Distance detection part 27 Speed detection part 28 Pair determination part 29 Direction detection part 30 Folding target determination part 31 Target determination part

Claims (5)

A radar device for detecting a position or velocity of the target or a position and velocity of the target from a reflected signal from the target,
A transmitter for transmitting modulated waves having the same sweep bandwidth and different modulation frequencies as transmission signals;
A receiving unit that receives a reflected signal from the target with respect to a transmission signal transmitted by the transmitting unit;
A beat signal generation unit that generates a beat signal by mixing the transmission signal and the reception signal received by the reception unit;
Based on the reception level of the beat signal, it is determined whether or not it is a folding target of a long-distance object, and when it is a folding target, a folding target determination unit that removes information based on the folding target;
A radar apparatus comprising: The folded target determination unit
Based on the reception level of the beat signal of the reception signal with respect to the transmission signal having a shorter period and the beat signal of the reception signal with respect to the transmission signal having a longer period among the transmission signals, the return of the object at a long distance The radar apparatus according to claim 1, wherein it is determined whether or not it is a target, and if the target is a return target, information based on the return target is removed. The folded target determination unit
Based on the background noise level included in the beat signal of the received signal with respect to one of the transmission signals among the transmission signals, it is determined whether the target is a folding target of a long-distance object, and the folding target The radar apparatus according to claim 1, wherein it is determined whether or not to remove information based on. A position / velocity detection method for detecting a position or velocity of the target or a position and velocity of the target from a reflected signal from the target,
A step of transmitting, as a transmission signal, a modulated wave having the same sweep bandwidth and different modulation frequencies,
Receiving a reflected signal from the target with respect to the transmission signal;
A beat signal generation unit that generates a beat signal by mixing the transmission signal and the reception signal received by the reception unit;
A step of determining whether the return target is a return target of a long-distance object based on the reception level of the beat signal, and removing information based on the return target when the return target is a return target; When,
A position / velocity detection method comprising: A radar apparatus computer that detects the position or velocity of the target from the reflected signal from the target, or the position and velocity of the target,
A transmission procedure for transmitting modulated waves having the same sweep bandwidth and different modulation frequencies as transmission signals;
A receiving procedure for receiving a reflected signal from the target for the transmitted signal;
A beat signal generation procedure for generating a beat signal by mixing the transmission signal and the received reception signal;
Based on the reception level with the beat signal, it is determined whether or not the target is a return target of a long-distance object, and in the case of a return target, a return target determination procedure for removing information based on the return target;
A program characterized by having executed.

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