JPWO2016080156A1 - Radar equipment - Google Patents

Abstract

A radar device capable of determining whether a detected obstacle is a close object of a plurality of objects or a single object is obtained. The mixer (5) generates a beat signal from the transmission signal and the reception signal, the frequency analysis unit (6) calculates a first frequency spectrum from the beat signal, and the obstacle detection unit (7) The obstacle superimposition determination unit (8) compares the plurality of second frequency spectra stored in advance with the first frequency spectrum, and the similar second frequency spectrum is detected. In some cases, the obstacle is determined to be a single object, and when there is no similar second frequency spectrum, it is determined that the obstacle is a plurality of objects.

Description

  The present invention relates to a radar device that transmits FM-modulated radio waves and detects surrounding obstacles.

  Conventionally, it is installed in a vehicle and detects surrounding obstacles (large vehicles, ordinary four-wheeled vehicles, two-wheeled vehicles, etc.) using radio waves, and the relative distance and relative speed between the vehicle (own vehicle) and the detected obstacles. There is a radar device that measures. There has also been proposed an in-vehicle radar device that determines whether a detected obstacle is a two-wheeled vehicle or a four-wheeled vehicle. For example, in Patent Document 1, in a vehicle-mounted radar device, a plurality of adjacent beams are formed, and the intensity of received signals with respect to the adjacent beams is compared to determine whether the vehicle is a two-wheeled vehicle or a four-wheeled vehicle. Further, in Patent Document 1, data on the intensity of received signals from several types of vehicles (large vehicles, ordinary four-wheeled vehicles, two-wheeled vehicles, etc.) is stored in advance for each relative distance from the own vehicle, and detected obstacles. The vehicle type is determined by comparing the received signal intensity with the relative distance.

JP-A-6-16297

  In such a conventional radar apparatus, when a plurality of objects are approaching, a plurality of frequency spectra are overlapped when frequency analysis such as fast Fourier transform (hereinafter referred to as “FFT”) is performed. Therefore, there is a problem that it is impossible to determine whether the detected obstacle is a close object or a single object. As a result, for example, it has not been possible to determine that the error is large because information on a plurality of objects is mixed in the relative distance and relative speed with the detected obstacle. Further, for example, when determining the vehicle type of the detected obstacle, there is a possibility that erroneous determinations increase.

  The present invention has been made to solve the above problems, and a radar apparatus capable of determining whether a detected obstacle is a close object or a single object. The purpose is to obtain.

  A radar apparatus according to the present invention generates a transmission antenna that transmits a transmission signal to the outside, a reception antenna that receives a reception signal from the outside with respect to the transmission signal, and a beat signal that is a difference signal between the transmission signal and the reception signal. A mixer, a frequency analysis unit that performs frequency analysis on the beat signal to calculate a first frequency spectrum, an obstacle detection unit that detects an obstacle from the first frequency spectrum, and the obstacle detection unit An object superimposition determination unit that determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum, and the object superimposition determination unit includes a predetermined single object A frequency spectrum that is predicted to be calculated by the frequency analysis unit when it exists as an obstacle, and is a frequency spectrum that reflects the uneven shape of a predetermined single object. The spectrum storage unit that stores the frequency spectrum in advance for each predetermined single object, and each of the second frequency spectrum and the first frequency spectrum is compared, and the obstacle is a plurality of objects or a single object. And a spectrum comparison unit for determining whether or not.

  A radar apparatus according to the present invention generates a transmission antenna that transmits a transmission signal to the outside, a reception antenna that receives a reception signal from the outside with respect to the transmission signal, and a beat signal that is a difference signal between the transmission signal and the reception signal. A mixer, a frequency analysis unit that performs frequency analysis on the beat signal to calculate a first frequency spectrum, an obstacle detection unit that detects an obstacle from the first frequency spectrum, and the obstacle detection unit An object superimposition determination unit that determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum, and the object superimposition determination unit includes a predetermined single object A frequency spectrum that is predicted to be calculated by the frequency analysis unit when it exists as an obstacle, and is a frequency spectrum that reflects the uneven shape of a predetermined single object. The spectrum storage unit that stores the frequency spectrum in advance for each predetermined single object, and each of the second frequency spectrum and the first frequency spectrum is compared, and the obstacle is a plurality of objects or a single object. And a spectrum comparison unit that determines whether the detected obstacle is a close object of a plurality of objects or a single object.

It is a block diagram of the radar apparatus by Embodiment 1 of this invention. It is a figure showing an example of the transmission signal in the radar apparatus by Embodiment 1 of this invention. It is a block diagram of the object superimposition determination part in the radar apparatus by Embodiment 1 of this invention. It is a schematic diagram for demonstrating the 1st frequency spectrum and 2nd frequency spectrum in the radar apparatus by Embodiment 1 of this invention. It is a block diagram of the error estimation part in the radar apparatus by Embodiment 1 of this invention. It is a figure for demonstrating the output from the error estimation part in the radar apparatus by Embodiment 1 of this invention. It is a figure showing an example of the processing flow in the radar apparatus by Embodiment 1 of this invention. It is a block diagram of the radar apparatus by Embodiment 2 of this invention. It is a block diagram of the radar apparatus by Embodiment 3 of this invention. It is a block diagram of the object superimposition determination part in the radar apparatus by Embodiment 3 of this invention. It is a schematic diagram for demonstrating operation | movement of the spectrum combination part in the radar apparatus by Embodiment 3 of this invention. It is a figure showing an example of the processing flow in the radar apparatus by Embodiment 3 of this invention. It is a block diagram of the radar apparatus by Embodiment 4 of this invention. It is a figure showing an example of the processing flow in the radar apparatus by Embodiment 4 of this invention. It is a figure showing an example of the transmission signal in the radar apparatus by Embodiment 4 of this invention. It is a block diagram of the radar apparatus by Embodiment 5 of this invention. It is a figure showing the structure of the object superimposition determination part in the radar apparatus by Embodiment 5 of this invention, and an external server. It is a figure which shows an example of the hardware constitutions of the radar apparatus by Embodiment 5 of this invention. It is a figure which shows another example of the hardware constitutions of the radar apparatus by Embodiment 5 of this invention.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a radar apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the radar apparatus according to the present embodiment includes a control voltage generation unit 1, an oscillator 2, a transmission antenna 3, a reception antenna 4, a mixer 5, a frequency analysis unit 6, and an obstacle detection. Unit 7, object superimposition determination unit 8, relative speed calculation unit 9, relative distance calculation unit 10, and error estimation unit 11. The radar apparatus according to the present embodiment is mounted on a vehicle, and the output of the error estimation unit 11 is input to the control unit 12 provided outside the radar apparatus. Hereinafter, a vehicle on which the radar apparatus according to the present embodiment is mounted is referred to as a host vehicle.

  The control voltage generation unit 1, the frequency analysis unit 6, the obstacle detection unit 7, the object superimposition determination unit 8, the relative speed calculation unit 9, the relative distance calculation unit 10, and the error estimation unit 11 may be configured by electronic circuits. it can. In addition, the control voltage generation unit 1, the frequency analysis unit 6, the obstacle detection unit 7, the object superimposition determination unit 8, the relative speed calculation unit 9, the relative distance calculation unit 10, and the error estimation unit 11 store programs stored in the memory. It can also be realized by processing with a computer.

  The control voltage generation unit 1 generates a control voltage for generating a transmission signal composed of a CW signal that is a continuous wave of an arbitrary natural frequency and an FM signal that is FM-modulated. FIG. 2 is a diagram illustrating an example of a transmission signal in the radar apparatus of the present embodiment, where the horizontal axis represents time and the vertical axis represents frequency. However, the transmission signal shown in FIG. 2 is merely an example, and is not limited to the waveform. For example, a triangular waveform FM signal may be generated after the CW signal. The oscillator 2 generates a transmission signal whose frequency changes according to the control voltage. The frequency of the transmission signal is referred to as a transmission frequency. The transmission antenna 3 transmits a transmission signal to the outside.

  The reception antenna 4 receives a reception signal from the outside with respect to the transmission signal transmitted by the transmission antenna 3. The frequency of the received signal is referred to as the received frequency. The mixer 5 generates a beat signal that is a difference between the transmission signal and the reception signal. The frequency of the beat signal is referred to as the beat frequency. The frequency analysis unit 6 performs a frequency analysis of the beat signal and obtains a first frequency spectrum that is a frequency spectrum of the beat signal. The obstacle detection unit 7 detects the presence or absence of an obstacle around the vehicle from the first frequency spectrum. The obstacle detection unit 7 detects the presence or absence of an obstacle using, for example, the peak intensity of the first frequency spectrum. The obstacle detection unit 7 can also be configured to detect the presence or absence of an obstacle using the intensity distribution of the first frequency spectrum.

  When the obstacle detection unit 7 detects an obstacle, the object superposition determination unit 8 determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum. As will be described later, the object superimposition determination unit 8 determines whether the obstacle is a close object or a single object from the distribution shape of the first frequency spectrum. The relative speed calculation unit 9 calculates the relative speed between the detected obstacle and the host vehicle from the first frequency spectrum. The relative distance calculation unit 10 calculates the relative distance from the host vehicle to the detected obstacle from the first frequency spectrum.

  The error estimation unit 11 estimates the error included in the relative speed calculated by the relative speed calculation unit 9 and the error included in the relative distance calculated by the relative distance calculation unit 10 from the determination result of the object superimposition determination unit 8. . The error estimation unit 11 outputs the relative speed with the obstacle, the relative distance to the obstacle, and the estimated error. The control unit 12 provided outside the radar apparatus determines the optimal control content and timing for the host vehicle from the relative speed with the obstacle, the relative distance to the obstacle, and the estimated error, and determines the determination result. Based on the control. Examples of the control performed by the control unit 12 include issuing an alarm such as approach detection, brake control, steering wheel control, accelerator control, and the like. The alarm can be issued via a display device or can be issued via a speaker. The above is the configuration of the radar apparatus according to the present embodiment.

  Next, the configuration of the object superimposition determination unit 8 in the radar apparatus of the present embodiment will be described. FIG. 3 is a configuration diagram of the object superimposition determination unit 8 in the radar apparatus of the present embodiment. As shown in FIG. 3, the object superimposition determination unit 8 includes a spectrum storage unit 81 and a spectrum comparison unit 82. The spectrum storage unit 81 stores in advance a frequency spectrum predicted to be calculated by the frequency analysis unit 6 for each object when a predetermined single object exists as an obstacle. That is, for an object that is assumed to exist as an obstacle, when the object exists alone, a frequency spectrum calculated by the frequency analysis unit 6 is obtained in advance and stored in the spectrum storage unit 81 for each object. deep. The frequency spectrum stored in the spectrum storage unit 81 is referred to as a second frequency spectrum.

  As the second frequency spectrum, only a representative frequency spectrum under a predetermined detection condition may be stored for each object, or a plurality of frequency spectra under a plurality of detection conditions may be stored for each object. May be. The detection condition refers to a relative distance to the object. Further, as the object for storing the second frequency spectrum, a plurality of types such as a large four-wheeled vehicle, a normal four-wheeled vehicle, and a two-wheeled vehicle are conceivable and may include other than a moving body.

  The spectrum comparison unit 82 compares the first frequency spectrum calculated by the frequency analysis unit 6 with each of the second frequency spectra stored in the spectrum storage unit 81, and detects a plurality of obstacles. It is determined whether it is an object or a single object.

  FIG. 4 is a schematic diagram for explaining the first frequency spectrum and the second frequency spectrum in the radar apparatus of the present embodiment. FIG. 4A is a schematic diagram illustrating a state in which a transmission signal is reflected by an obstacle and becomes a reception signal. FIG. 4A shows a case where the obstacle is a single object (large four-wheeled vehicle). A large four-wheeled vehicle that is an obstacle has a different relative distance from the host vehicle depending on the height, and a time from when the transmission signal is transmitted to when the reception signal is received also varies depending on the position where the transmission signal is reflected. FIG. 4B is a diagram illustrating an example of the time when the received signal reflected by the obstacle reaches the radar apparatus and the intensity of the received signal, where the horizontal axis represents time and the vertical axis represents the received signal intensity. FIG. 4C is a diagram illustrating an example of a frequency spectrum obtained by frequency analysis of a beat signal obtained from a received signal, where the horizontal axis represents frequency and the vertical axis represents spectrum intensity.

  For example, the time when the received signal reflected by the cross-sectional shape of a large four-wheeled vehicle as shown in FIG. 4 and its intensity are measured in advance, the frequency spectrum is calculated from the measured delay profile, and the second frequency spectrum is obtained. Store in the spectrum storage unit 81. When calculating the frequency spectrum from the delay profile, the same sampling conditions and frequency analysis parameters as those used in the radar apparatus of the present embodiment are used. Sampling conditions include the sampling rate and the number of bits during quantization. The frequency analysis parameters include the FFT score when performing frequency analysis by FFT. The number of FFT points is the number of data for performing FFT processing. In addition, as a frequency spectrum, the frequency spectrum from not only a back surface but a front surface, a rear side, etc. may be added, and the information of the Doppler component by a wheel which can be detected with a two-wheeled vehicle etc. may be added.

  The spectrum comparison unit 82 compares the first frequency spectrum and the second frequency spectrum. In this case, the characteristic that the radio wave attenuates according to the distance may be taken into consideration. Specifically, after the intensity of the second frequency spectrum is changed according to the relative distance calculated by the relative distance calculation unit 10, the obstacle is a plurality of objects or a single object compared to the first frequency spectrum. You may determine whether it is an object. In this case, it is conceivable that if the relative distance is long, the intensity of the second frequency spectrum is decreased, and if the relative distance is short, the intensity of the second frequency spectrum is increased.

  Next, the configuration of the error estimation unit 11 in the radar apparatus according to the present embodiment will be described. FIG. 5 is a configuration diagram of the error estimation unit 11 in the radar apparatus according to the present embodiment. As shown in FIG. 5, the error estimation unit 11 includes an error storage unit 111 and an error output unit 112. The error storage unit 111 stores in advance an error included in the relative speed calculated by the relative speed calculation unit 9 and an error included in the relative distance calculated by the relative distance calculation unit 10. As an error stored in the error storage unit 111, an error when the obstacle detected by the obstacle detection unit 7 is a plurality of objects and an error when the obstacle is a single object are stored.

  The error output unit 112 reads out the error stored in the error storage unit 111 according to the determination result in the object superimposition determination unit 8, adds it to the relative speed and the relative distance, and outputs it. The error output unit 112 outputs an error when the obstacle is a plurality of objects when the object superimposition determination unit 8 determines that the obstacle is a plurality of objects approaching. Is determined to be an singular object, an error is output when the obstacle is a singular object.

  In the radar apparatus according to the present embodiment, different errors are stored depending on whether the detected obstacle is a plurality of objects or a single object, but other structures may be used. . As the relative distance is shorter, the intensity of the received signal becomes stronger and the S / N ratio of the received signal is improved. Therefore, the error storage unit 111 may store different errors depending on the relative distance, and the error output unit 112 may read the error according to the determination result in the object superimposition determination unit 8 and the relative distance.

  Further, the error included in the relative distance and the relative speed also changes depending on the analysis parameter used in the frequency analysis circuit 6. For example, when the frequency analysis unit 6 performs frequency analysis using FFT, the number of FFT points is an analysis parameter. When analog data is also quantized by the frequency analysis unit 6, the sampling conditions for the quantization can also be included in the analysis parameters. Therefore, the error storage unit 111 stores different errors depending on the analysis parameters used in the frequency analysis unit 6, and the error output unit 112 reads out the errors according to the determination result in the object superimposition determination unit 8 and the analysis parameters. May be.

  FIG. 6 is a diagram for explaining an output from the error estimation unit 11. In FIG. 6, the horizontal axis represents relative speed, and the vertical axis represents relative distance. A in FIG. 6 represents the relative speed calculated by the relative speed calculation unit 9 and the relative distance calculated by the relative distance calculation unit 10. B in FIG. 6 represents a range of error between the relative speed calculated by the relative speed calculation unit 9 and the relative distance calculated by the relative distance calculation unit 10 when the obstacle is a single object. C in FIG. 6 represents a range of errors between the relative speed calculated by the relative speed calculation unit 9 and the relative distance calculated by the relative distance calculation unit 10 when the obstacle is a plurality of objects.

  FIG. 6 shows an example of output in which an error range is added to the relative speed and relative distance, but the error estimation unit 11 may output in another format. For example, the relative distance at which the closest approach that is most likely to be the most dangerous state may be output in consideration of the error. Further, for example, the relative speed approaching the fastest may be output in consideration of the error. Further, TTC (Time to Collision), which is the time until the collision that can be calculated from the relative speed and the relative distance, may be output.

  Next, the operation of the radar apparatus according to this embodiment will be described in more detail. FIG. 7 is a diagram illustrating an example of a processing flow in the radar apparatus according to the present embodiment. Hereinafter, the processing flow of the radar apparatus according to the present embodiment will be described with reference to FIG. When the radar apparatus according to the present embodiment starts measurement, the radar apparatus performs the process of step S701. In step S701, the control voltage generator 1 generates a control voltage, the oscillator 2 generates a transmission signal whose frequency changes according to the control voltage, and the transmission antenna 3 transmits the transmission signal to the outside.

  Next, in step S702, the reception antenna 4 receives the reception signal, the mixer 5 generates a beat signal that is a difference between the transmission signal and the reception signal, and the frequency analysis unit 6 performs frequency analysis of the beat signal to perform the first analysis. The obstacle detector 7 detects the presence or absence of obstacles around the host vehicle from the first frequency spectrum. The frequency analysis unit 6 performs frequency analysis of the beat signal by FFT or the like.

  Here, the obstacle detection performed by the obstacle detection unit 7 will be described. When there is an obstacle, a Doppler component generated from the relative speed between the radar apparatus and the obstacle is detected from the received signal when the CW signal is transmitted. The Doppler frequency fd detected at that time is expressed by the following equation (1) depending on the relative velocity V and the transmission frequency f. Further, the frequency component of the frequency (fd + fr) obtained by adding the frequency fr of the following equation (2) corresponding to the relative distance R and the Doppler frequency fd is detected from the received signal when the FM signal is transmitted. . In Expression (2), Δf represents the amount of change per unit time in the frequency of the transmission signal, and C represents the speed of light.

  When there is an obstacle, the frequency components of the above frequencies fd and (fd + fr) are generated in the first frequency spectrum. The obstacle detection unit 7 compares the intensity of the first frequency spectrum with an arbitrary threshold value, and determines that an obstacle is present when there is a frequency component exceeding the threshold value in the first frequency spectrum. On the other hand, when there is no frequency component exceeding the threshold in the first frequency spectrum, it is determined that there is no obstacle. As for the threshold value, various methods have been proposed, such as a moving average method based on the relationship with ambient noise reflected from structures such as walls and utility poles that exist in the vicinity. It is not limited to any method.

  Although the description has been simplified in the above description, generally, the transmission signal is reflected at a plurality of points on the obstacle as shown in FIG. When the transmission signal is reflected at a plurality of points having different relative distances R, a plurality of frequency components corresponding to the frequency (fd + fr) are generated, and a first frequency spectrum is generated. Therefore, the intensity distribution of the first frequency spectrum depends on the relative distance to the plurality of reflection points that reflect the transmission signal and the reflection intensity at each reflection point. That is, the intensity distribution of the first frequency spectrum depends on the positional relationship between the reflection points on the obstacle and the reflection intensity on the reflection points, and therefore depends on the shape and material of the obstacle. Therefore, the intensity distribution of the first frequency spectrum differs depending on the obstacle. Similarly, the intensity distribution of the second frequency spectrum also differs depending on the object. That is, the intensity distribution of the second frequency spectrum also reflects the positional relationship of each reflection point on the object and the reflection intensity at each reflection point. In other words, the intensity distribution of the second frequency spectrum also reflects the uneven shape of the object.

  Further, when the obstacle is a thing in which a plurality of objects are approaching, a reception signal is a combination of reflected waves from the objects. In this case, information of a plurality of objects is mixed in the first frequency spectrum. In the obstacle detection unit 7, the obstacle is detected as described above. If it is determined in step S702 that there is an obstacle, the processing of the radar apparatus proceeds to step S703. On the other hand, if it is determined in step S702 that there is no obstacle, the processing of the radar apparatus returns to step S701.

  In step S703, the relative speed calculation unit 9 calculates the relative speed with the obstacle, and the relative distance calculation unit 10 calculates the relative distance to the obstacle. Pairing processing generally used in a radar apparatus using an FM-modulated transmission wave is also executed as necessary. The calculation of the relative speed with the obstacle is performed based on the first frequency spectrum with respect to the received signal when the CW signal is transmitted. Specifically, the relative speed calculation unit 9 detects the relative speed by extracting the frequency fd of the Doppler component depending on the relative speed that can be measured when the CW signal is transmitted and substituting it into the following equation (3). it can. As a method for extracting the frequency fd, for example, it is conceivable to extract a frequency at which the intensity of the first frequency spectrum is maximum.

  On the other hand, the calculation of the relative distance to the obstacle is performed based on the first frequency spectrum for the received signal when the CW signal and the FM signal are transmitted. Specifically, the relative distance calculation unit 10 extracts, for example, a Doppler frequency (fd + fr) that depends on a relative speed and a relative distance that can be measured when an FM signal is transmitted, and can be measured when a CW signal is transmitted. The relative distance can be calculated by subtracting the Doppler frequency fd depending on the speed, calculating the frequency fr according to the distance, and substituting it into the following equation (4). As a method of extracting the frequency (fd + fr), for example, it is conceivable to extract a frequency at which the intensity of the first frequency spectrum is maximum.

  Next, in step S704, the object superimposition determination unit 8 determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum. The object superposition determination unit 8 compares each of the plurality of second frequency spectra stored in the spectrum storage unit 81 with the first frequency spectrum, and determines whether the obstacle is a plurality of objects or a single object. Determine if there is. Specifically, the similarity between the shape of each intensity distribution of the second frequency spectrum and the shape of the intensity distribution of the first frequency spectrum is calculated, and the calculated similarities are both below a predetermined threshold. In this case, it is determined that the obstacle is a plurality of objects. On the other hand, if any of the calculated similarities is equal to or greater than a predetermined threshold, it is determined that the obstacle is a single object.

  As described above, the intensity distribution of the first frequency spectrum differs depending on the obstacle. Further, the second frequency spectrum is obtained in advance for a frequency spectrum in the case where the object is assumed to exist as an obstacle and the object exists alone. Therefore, by determining the similarity between the shape of the intensity distribution of the second frequency spectrum and the shape of the intensity distribution of the first frequency spectrum, it is determined whether the obstacle is a plurality of objects or a single object. It becomes possible to do.

  The first frequency spectrum and the second frequency spectrum may move in the frequency axis direction due to the difference in relative distance to the obstacle, but the object superimposition determination unit 8 has a shape of intensity distribution. Since the similarity is obtained, this influence is suppressed. The shape of the intensity distribution is a distribution of the relative intensity of the spectrum at each frequency with respect to the intensity of the spectrum at a predetermined reference frequency. When obtaining the similarity of the shape of the intensity distribution, the first frequency spectrum and the second frequency spectrum need not have the same reference frequency. As a method for calculating the similarity of the shape of the intensity distribution, various methods such as a correlation analysis method and pattern matching based on feature point extraction can be considered.

  The above is the operation of the laser apparatus in step S704. The object superimposition determination unit 8 determines that there are a plurality of objects if there is a possibility that the obstacle is a plurality of objects. If it is determined in step S704 that the obstacle is a plurality of objects, the processing of the radar apparatus proceeds to step S705. On the other hand, if it is determined in step S704 that the obstacle is a single object, the processing of the radar apparatus proceeds to step S706.

  In step S705, the error estimation unit 11 adds an error when the obstacle is a plurality of objects to the relative speed and the relative distance, and outputs the result. In step S706, the error estimation unit 11 adds an error when the obstacle is a single object to the relative speed and the relative distance and outputs the added error. Note that the error when the obstacle is a single object may have a different value depending on the second frequency spectrum similar to the first frequency spectrum.

  As described above, when the obstacle is a thing in which a plurality of objects are close to each other, information on the plurality of objects is mixed in the first frequency spectrum. Therefore, in general, the error included in the relative velocity and the relative distance obtained from the first frequency spectrum is larger than that in the case where the obstacle is a single object. Considering this, the error added in step S705 is made larger than the error added in step S706. As described above, the object superimposition determination unit 8 determines that there are a plurality of objects if there is a possibility that the obstacle is a plurality of objects. Therefore, when there is a possibility that the obstacle is a plurality of objects, the error estimation unit 11 adds a large error. The above is the processing of the radar apparatus of the present embodiment.

  Steps S707 and S708 are processing of the control unit 12. In step S707, the control unit 12 determines whether or not control of the host vehicle is necessary based on the relative speed and error with respect to the obstacle output from the radar device and the relative distance and error to the obstacle. If it is determined that control of the host vehicle is necessary, the process of the control unit 12 proceeds to step S708. If it is determined that control of the host vehicle is not necessary, the control unit 12 ends the process, and the radar apparatus starts the process of S701. In step S708, the control unit 12 determines the optimal control content and timing for the host vehicle, and performs control based on the determination result.

  As described above, the radar apparatus according to the present embodiment includes the transmission antenna 3 that transmits a transmission signal to the outside, the reception antenna 4 that receives a reception signal from the outside with respect to the transmission signal, the transmission signal and the reception signal, A mixer 5 that generates a beat signal that is a difference signal of the signal, a frequency analysis unit 6 that performs frequency analysis on the beat signal to calculate a first frequency spectrum, and detects an obstacle from the first frequency spectrum. An obstacle detection unit 7 and an object superposition determination unit 8 that determines whether the obstacle is a plurality of objects or a single object when an obstacle is detected by the obstacle detection unit from the first frequency spectrum; Therefore, it is possible to determine whether the detected obstacle is a close object or a single object.

  In addition, a relative speed calculation unit 9 that calculates a relative speed from the first frequency spectrum to the obstacle, a relative distance calculation unit 10 that calculates a relative distance from the first frequency spectrum to the obstacle, and an object superimposition determination unit Since the error estimation unit 11 that estimates the error included in the relative distance and the relative speed from the determination result of 8 is provided, an appropriate error can be output according to the state of the obstacle. As a result, the vehicle on which the radar apparatus is mounted can be appropriately controlled according to the relative speed with the obstacle, the relative distance to the obstacle, and the error included in the relative distance and the relative speed. .

  In a conventional radar apparatus, when a plurality of objects are approaching as an obstacle, information on the plurality of objects may be mixed in the relative distance and relative speed with the detected obstacle, and the error may increase. there were. Therefore, when a conventional radar device is mounted on a vehicle and control is performed to issue an approach warning or stop the vehicle using the relative distance and relative speed with the detected obstacle, appropriate control is performed. There was a possibility that it could not be done. On the other hand, according to the radar apparatus of the present embodiment, it is possible to determine that a plurality of objects are approaching as an obstacle and the frequency spectrum for the received signals from the plurality of objects is superimposed, and more appropriate control is performed. There is a remarkable effect that it can be performed. In addition, although the radar apparatus of this Embodiment demonstrated the example mounted in a vehicle, it is not necessarily limited to this.

Embodiment 2
FIG. 8 is a configuration diagram of a radar apparatus according to Embodiment 2 of the present invention. The radar apparatus according to the present embodiment is different from that according to the first embodiment in that it does not include the relative velocity calculation unit 9, the relative distance calculation unit 10, and the error estimation unit 11. In addition, a vehicle type determination unit 13 is provided outside the radar apparatus according to the present embodiment. In FIG. 8, the same reference numerals as those in FIG. 1 of the first embodiment are the same, and detailed description thereof is omitted. Hereinafter, the radar apparatus according to the present embodiment will be described.

  As in the first embodiment, the obstacle detection unit 8 calculates the degree of similarity between the shape of each intensity distribution of the second frequency spectrum and the shape of the intensity distribution of the first frequency spectrum. If all the similarities are below a predetermined threshold, it is determined that the obstacle is a plurality of objects. On the other hand, if any of the calculated similarities is equal to or greater than a predetermined threshold, it is determined that the obstacle is a single object.

  The vehicle type determination unit 13 stores a corresponding vehicle type in advance for each of the second frequency spectra. When the object superimposition determination unit 8 determines that the obstacle is a single object, the vehicle type determination unit 13 responds according to which of the second frequency spectra is similar to the first frequency spectrum. The vehicle model to be output is output. On the other hand, when the object superimposition determination unit 8 determines that the obstacle is a plurality of objects, the vehicle type determination unit 13 outputs that the vehicle type cannot be determined. When there are a plurality of second frequency spectra similar to the first frequency spectrum, it is conceivable to select the second frequency spectrum that is most similar.

  In the radar apparatus according to the present embodiment, it is possible to reduce the possibility of detection as a single object when a plurality of objects are approaching. Therefore, when determining the vehicle type of the detected obstacle, it is possible to suppress erroneous determination of the vehicle type by detecting a plurality of objects as a single object.

Embodiment 3
FIG. 9 is a configuration diagram of a radar apparatus according to Embodiment 3 of the present invention. The radar apparatus according to the present embodiment is different from that according to the first embodiment in the configuration of the object superimposition determination unit 8b. The radar apparatus according to the present embodiment is different from that according to the first embodiment in that a position estimation unit 14 is provided instead of the error estimation unit 11. In FIG. 9, the same reference numerals as those in FIG. 1 of the first embodiment denote the same parts, and a detailed description thereof will be omitted. Hereinafter, the radar apparatus according to the present embodiment will be described.

  FIG. 10 is a configuration diagram of the object superimposition determination unit 8b in the radar apparatus according to the present embodiment. As shown in FIG. 10, the object superimposition determination unit 8b includes a spectrum storage unit 81, a spectrum comparison unit 82b, and a spectrum combination unit 83. The spectrum storage unit 81 is the same as that in the first embodiment. The spectrum combination unit 83 generates a third frequency spectrum by combining a plurality of second frequency spectra stored in the spectrum storage unit 81. When combining the plurality of second frequency spectra, the spectrum combining unit 83 combines the respective frequencies in a shifted state.

  FIG. 11 is a schematic diagram for explaining the operation of the spectrum combination unit 83 in the radar apparatus of the present embodiment. 11A to 11E, the horizontal axis represents frequency, and the vertical axis represents spectrum intensity. FIGS. 11A and 11B show examples of the second frequency spectrum stored in the spectrum storage unit 81. For example, FIG. 11 (a) is a second frequency spectrum corresponding to a large four-wheeled vehicle, and FIG. 11 (b) is a second frequency spectrum corresponding to a two-wheeled vehicle. FIGS. 11C and 11D show frequency spectra obtained by shifting the frequency of the second frequency spectrum. Shifting the frequency means translating the intensity distribution of the frequency spectrum in the frequency axis direction. In FIG. 11, the second frequency spectrum of FIG. 11A is shifted in the higher frequency direction, and the second frequency spectrum of FIG. 11B is shifted in the lower frequency direction.

  FIG. 11 (e) represents a third frequency spectrum obtained by combining the frequency spectra of FIGS. 11 (c) and 11 (d). In the radar apparatus of the present embodiment, the frequency spectrum is added when combining the frequency spectra. In addition, although the example which shifts both the frequencies of two 2nd frequency spectrum was described here, it is not limited to this. Only one of the frequencies may be shifted, and it is only necessary to relatively change the positional relationship in the frequency direction between the combined frequency spectra. Further, the second frequency spectrum to be combined is not limited to two, and may be three or more.

  Furthermore, when combining a plurality of second frequency spectra, the spectrum combining unit 83 can generate a third frequency spectrum by combining the second frequency spectra after changing their intensities. Specifically, the spectrum combination unit 83 does not simply add the frequency spectrum to generate the third frequency spectrum, but performs weighted addition that multiplies each frequency spectrum after adding the coefficient and adds the result. Three frequency spectra can also be generated. The spectrum combining unit 83 sequentially generates the third frequency spectrum by changing the second frequency spectrum to be combined, the coefficient to be multiplied by the frequency spectrum, and the direction and magnitude of shifting the frequency when combining the frequency spectrum in various ways. .

  First, the spectrum comparison unit 82b compares each of the second frequency spectrums with the first frequency spectrum to determine whether the obstacle is a close object of a plurality of objects or a single object. . If it is determined that the obstacle is a plurality of objects, then the similarity between the third frequency spectrum and the first frequency spectrum is calculated, and the third frequency spectrum with the highest similarity is obtained. . Note that the spectrum comparison unit 82b compares the third frequency spectrum with the first frequency spectrum, but in this case, the characteristic that the radio wave attenuates according to the distance may be taken into consideration. Specifically, the intensity of the third frequency spectrum may be changed according to the relative distance calculated by the relative distance calculation unit 10 and then compared with the first frequency spectrum.

  When the position estimation unit 14 determines that the obstacle is a plurality of objects, the frequency between the second frequency spectrum and the third frequency spectrum having the highest similarity obtained by the spectrum comparison unit 82b. The distance between a plurality of objects is obtained from the amount of deviation. That is, the position estimation unit 14 obtains the distances between the plurality of objects based on information on how much the spectrum combining unit 83 has shifted the frequency of the second frequency spectrum. Further, the position estimation unit 14 estimates the position of the object closest to the radar apparatus from the distance between the plurality of objects and the relative distance calculated by the relative distance calculation unit 10. On the other hand, when it is determined that the obstacle is a single object, the position estimation unit 14 estimates the position of the object closest to the radar apparatus from the relative distance calculated by the relative distance calculation unit 10. The position estimation unit 14 outputs the relative speed with the obstacle and the position of the object closest to the radar apparatus.

  FIG. 12 is a diagram illustrating an example of a processing flow in the radar apparatus according to the present embodiment. Hereinafter, the processing flow of the radar apparatus according to the present embodiment will be described with reference to FIG. When the radar apparatus according to the present embodiment starts measurement, it performs the process of step S1201. In step S1201, the control voltage generator 1 generates a control voltage, the oscillator 2 generates a transmission signal whose frequency changes according to the control voltage, and the transmission antenna 3 transmits the transmission signal to the outside.

  Next, in step S1202, the reception antenna 4 receives the reception signal, the mixer 5 generates a beat signal that is the difference between the transmission signal and the reception signal, and the frequency analysis unit 6 performs frequency analysis of the beat signal to perform the first analysis. The obstacle detector 7 detects the presence or absence of obstacles around the host vehicle from the first frequency spectrum. If it is determined in step S1202 that an obstacle is present, the processing of the radar apparatus proceeds to step S1203. On the other hand, if it is determined in step S1202 that there is no obstacle, the radar apparatus returns to step S1201.

  In step S1203, the relative speed calculation unit 9 calculates the relative speed with the obstacle, and the relative distance calculation unit 10 calculates the relative distance to the obstacle. Next, in step S1204, the object superimposition determination unit 8b determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum. If it is determined in step S1204 that the obstacle is a plurality of objects, the processing of the radar apparatus proceeds to step S1205. On the other hand, if it is determined in step S1204 that the obstacle is a single object, the processing of the radar apparatus proceeds to step S1208. Note that the processing from step S1201 to S1204 is the same as the processing from step S701 to S704 in the first embodiment.

  In step S1205, the object superimposition determination unit 8b generates a third frequency spectrum by combining a plurality of second frequency spectra, and obtains the similarity between the third frequency spectrum and the first frequency spectrum. The object superposition determination unit 8b sequentially generates the third frequency spectrum by changing the second frequency spectrum to be combined, the coefficient to be multiplied by the frequency spectrum, and the direction and magnitude of shifting the frequency when combining the frequency spectrum in various ways. Then, the third frequency spectrum having the highest similarity with the first frequency spectrum is obtained.

  Next, in step S1206, the position estimation unit 14 obtains distances between a plurality of objects detected as obstacles. When there are a plurality of objects, the frequency at which the frequency spectrum corresponding to each object is generated varies depending on the relative distance from the radar apparatus to each object. The position estimation unit 14 utilizes this phenomenon and obtains the distance between a plurality of objects by the above-described operation. Next, in step S1207, the position estimation unit 14 estimates the position of the object closest to the radar apparatus from the distance between the plurality of objects and the relative distance calculated by the relative distance calculation unit 10. Specifically, the position estimating unit 14 subtracts the distances between the plurality of objects from the relative distance calculated by the relative distance calculating unit 10 to estimate the position of the closest object. On the other hand, in step S1208, the position estimation unit 14 sets the relative distance calculated by the relative distance calculation unit 10 as the position of the object closest to the radar apparatus. The above is the processing of the radar apparatus of the present embodiment.

  Steps S1209 and S1210 are processing of the control unit 12. In step S1209, the control unit 12 determines whether or not control of the host vehicle is necessary based on the relative speed with respect to the obstacle output from the radar device and the position of the object closest to the radar device. If it is determined that control of the host vehicle is necessary, the process of the control unit 12 proceeds to step S1210. If it is determined that control of the host vehicle is not necessary, the control unit 12 ends the process, and the radar apparatus starts the process of S1201. In step S1210, the control unit 12 determines the content and timing of the optimal control for the host vehicle, and performs control based on the determination result.

  In the radar apparatus according to the present embodiment, when a plurality of objects are close as obstacles, the position estimation unit 14 estimates the distance between the plurality of objects. Therefore, even when a plurality of objects are close as obstacles, the relative distance from the radar apparatus to each object can be obtained, and the position of the closest object from the radar apparatus can be obtained. Therefore, by mounting the radar apparatus according to the present embodiment on a vehicle, there is a remarkable effect that more appropriate vehicle control can be performed.

Embodiment 4 FIG.
FIG. 13 is a configuration diagram of a radar apparatus according to Embodiment 4 of the present invention. The radar apparatus according to the present embodiment is different from that according to the first embodiment in that the error estimation unit 11 is not provided. In addition, the radar apparatus according to the present embodiment includes an unnecessary wave removing unit 15, switches 16 a and 16 b, a reception control unit 17, an unnecessary object selection unit 18, a movement prediction unit 19, and a transmission signal control unit 20. It differs from the thing in Embodiment 1 by the point provided. In FIG. 13, the same reference numerals as those in FIG. 1 of the first embodiment are the same, and detailed description thereof is omitted. Hereinafter, the radar apparatus according to the present embodiment will be described.

  The unnecessary wave removal unit 15 removes unnecessary frequency components included in the beat signal before the frequency analysis unit 6 performs frequency analysis. The switches 16 a and 16 b switch a signal path from the mixer 5 to the frequency analysis unit 6 in order to turn on / off the operation of the unnecessary wave removal unit 15. The reception control unit 17 controls the operation of the switches 16a and 16b. When the obstacle is a plurality of objects, the unnecessary object selection unit 18 selects an unnecessary object from among the plurality of objects, and selects a frequency component from the unnecessary object included in the beat signal. The movement prediction unit 19 performs movement prediction of an unnecessary object selected by the unnecessary object selection unit 18. The transmission signal control unit 20 transmits the frequency component from the unnecessary object included in the beat signal based on the movement prediction result in the movement prediction unit 19 so that the frequency component is removed by the unnecessary wave removal unit 15. Control changes in signal frequency per unit time.

  FIG. 14 is a diagram illustrating an example of a processing flow in the radar apparatus according to the present embodiment. Hereinafter, a processing flow of the radar apparatus according to the present embodiment will be described with reference to FIG. When the radar apparatus according to the present embodiment starts measurement, it performs the process of step S1401. In step S1401, the reception control unit 17 controls the switches 16a and 16b to switch the transmission path of the beat signal so that the function of the unnecessary wave removal unit 15 is turned off. Next, in step S1402, the control voltage generation unit 1b generates a predetermined control voltage, the oscillator 2 generates a transmission signal whose frequency changes according to the control voltage, and the transmission antenna 3 transmits the transmission signal to the outside. To do. In step S1402, for example, the radar apparatus transmits a transmission signal such that an up chirp that increases the frequency with time and a down chirp that decreases the frequency with time have an equal triangular waveform. FIG. 15 is a diagram illustrating an example of a transmission signal in the radar apparatus of the present embodiment, where the horizontal axis represents time and the vertical axis represents frequency.

  Next, in step S1403, the reception antenna 4 receives the reception signal, the mixer 5 generates a beat signal, the frequency analysis unit 6 performs frequency analysis of the beat signal, obtains a first frequency spectrum, and detects an obstacle. The unit 7 detects the presence or absence of an obstacle around the host vehicle from the first frequency spectrum. If it is determined in step S1403 that an obstacle is present, the processing of the radar apparatus proceeds to step S1404. On the other hand, if it is determined in step S1403 that no obstacle exists, the processing of the radar apparatus returns to step S1402.

  In step S1404, the relative speed calculation unit 9 calculates the relative speed with the obstacle, and the relative distance calculation unit 10 calculates the relative distance to the obstacle. Next, in step S1405, the object superposition determination unit 8b determines whether the obstacle is a plurality of objects or a single object from the first frequency spectrum. If it is determined in step S1405 that the obstacle is a plurality of objects, the processing of the radar apparatus proceeds to step S1406. On the other hand, if it is determined in step S1405 that the obstacle is a single object, the processing of the radar apparatus proceeds to step S1413. Note that the processing from step S1403 to S1405 is the same as the processing from step S702 to S704 in the first embodiment.

  In step S1406, the unnecessary object selection unit 18 selects an unnecessary object from a plurality of objects, and selects a frequency component from the unnecessary object included in the beat signal. Specifically, the unnecessary object selection unit 18 selects a frequency component that seems to be a frequency component from an unnecessary object from the first frequency spectrum. The unnecessary object means an object to be excluded from detection targets among a plurality of objects detected as obstacles. In addition, as a reference for selecting an unnecessary object, it is conceivable to select an object having a long relative distance from the radar device among a plurality of objects. In this case, a high frequency component is removed from the first frequency spectrum. By excluding objects with a long relative distance from the radar device, the position of an object with a close relative distance can be accurately measured.

  Next, in step S1407, the movement prediction unit 19 performs an unnecessary object movement prediction based on the relative speed calculated by the relative speed calculation unit 9 and the relative distance calculated by the relative distance calculation unit 10, The position and relative speed of an unnecessary object at the time of transmission of the next transmission signal are predicted. Specifically, for example, assuming that the calculated relative speed continues in the next measurement, it can be considered that the relative distance changes at the time until the next measurement at this relative speed. Furthermore, as a means for predicting movement using the past relative distance and relative speed, there is a method using a Kalman filter, for example. By using statistical processing in this way, it is possible to accurately grasp the relative position and relative speed of the object at the next measurement time.

  Next, in step S1408, the reception control unit 17 controls the switches 16a and 16b to switch the transmission path of the beat signal so that the function of the unnecessary wave removal unit 15 is turned on. Next, in step S1409, the transmission signal control unit 20 generates a transmission control signal for controlling the change of the frequency of the transmission signal per unit time based on the movement prediction result in the movement prediction unit 19.

  The transmission signal control unit 20 generates a transmission control signal so that a frequency component from an unnecessary object included in the beat signal for the next transmission signal becomes a frequency component removed by the unnecessary wave removal unit 15. The transmission signal control unit 20 controls the change of the frequency of the transmission signal per unit time by the transmission control signal. Next, in step S1410, the control voltage generator 1b generates a control voltage based on the transmission control signal from the transmission signal controller 20, and the oscillator 2 generates a transmission signal whose frequency changes according to the control voltage. The transmission antenna 3 transmits a transmission signal to the outside.

  In step S1411, the receiving antenna 4 receives the received signal, the mixer 5 generates a beat signal, the unnecessary wave removing unit 15 removes unnecessary frequency components included in the beat signal, and the frequency analyzing unit 6 The first frequency spectrum is obtained by performing frequency analysis of the beat signal from which unnecessary frequency components are removed, and the obstacle detection unit 7 detects the presence or absence of an obstacle around the host vehicle from the first frequency spectrum. If it is determined in step S1411 that there is an obstacle, the processing of the radar apparatus proceeds to step S1412. On the other hand, if it is determined in step S1411 that there is no obstacle, the processing of the radar apparatus proceeds to step S1413.

  In step S1412, the relative speed calculation unit 9 corrects the relative speed with the obstacle based on the first frequency spectrum from which unnecessary frequency components are removed, and the relative distance calculation unit 10 calculates the relative distance to the obstacle. Correct it. The above is the processing of the radar apparatus of the present embodiment.

  Step S1413 and step S1414 are processing of the control unit 12. In step S1413, the control unit 12 determines whether or not control of the host vehicle is necessary based on the relative speed with the obstacle output from the radar device and the relative distance to the obstacle. If it is determined that control of the host vehicle is necessary, the process of the control unit 12 proceeds to step S1414. If it is determined that control of the host vehicle is not necessary, the control unit 12 ends the process, and the radar apparatus starts the process of S1401. In step S1414, the control unit 12 determines the optimal control content and timing for the host vehicle, and performs control based on the determination result.

  The radar apparatus according to the present embodiment selects an unnecessary object to be excluded from the detection target when the detected obstacle is a close object of a plurality of objects, and extracts a frequency component from the unnecessary object from the beat signal. A relative distance to the obstacle and a relative speed with respect to the obstacle are obtained based on the beat signal that has been removed and the frequency component from the unnecessary object is removed. Therefore, by mounting the radar apparatus of this embodiment on a vehicle, it is possible to accurately determine the position of the object closest to the host vehicle even if the detected obstacle is a plurality of objects close to each other. Thus, there is a remarkable effect that more appropriate vehicle control can be performed. In addition, the radar apparatus according to the present embodiment does not select an unnecessary object when the detected obstacle is a single object, and therefore, compared with a case where an unnecessary object is always selected. As a result, the processing becomes faster and the obstacle detection cycle can be shortened.

Embodiment 5. FIG.
FIG. 16 is a configuration diagram of a radar apparatus according to Embodiment 5 of the present invention. The radar apparatus according to the present embodiment is configured so that the second frequency spectrum can be updated at any time. The radar apparatus according to the present embodiment is different from that according to the first embodiment in the configuration of the object superimposition determination unit 8c. In FIG. 16, the same reference numerals as those in FIG. 1 of the first embodiment are the same, and detailed description thereof is omitted. Hereinafter, the radar apparatus according to the present embodiment will be described.

  FIG. 17 is a diagram illustrating the configuration of the object superimposition determination unit 8c and the external server 200 in the radar apparatus according to the present embodiment. As illustrated in FIG. 17, the object superimposition determination unit 8 c includes a spectrum acquisition unit 84 so that the second frequency spectrum stored in the spectrum storage unit 81 can be updated as needed. The object superimposition determination unit 8c also includes a spectrum storage unit 81 and a spectrum comparison unit 82, which are the same as those in the first embodiment. The external server 200 is provided outside the vehicle on which the radar device is mounted.

  The spectrum acquisition unit 84 acquires the frequency spectrum stored in the external server 200 through wireless communication, and updates the second frequency spectrum stored in advance in the spectrum storage unit 81. First, the spectrum acquisition unit determines whether there is a frequency spectrum stored in the external server 200 that is newer than the second frequency spectrum stored in the spectrum storage unit 81. It is determined whether or not to acquire a frequency spectrum from the external server 200. For example, the spectrum acquisition unit 84 inquires the external server 200 about the update date and time of the frequency spectrum, and determines whether or not to acquire the frequency spectrum. This inquiry may be executed in accordance with a user operation, or may be executed periodically. As another example, the external server 200 may notify the spectrum acquisition unit 84 every time the frequency spectrum is updated.

  The frequency spectrum stored in the external server 200 is updated when a new vehicle is released. The frequency spectrum stored in the external server 200 may include a frequency spectrum corresponding to an obstacle other than the vehicle. The radar apparatus according to the present embodiment includes a spectrum acquisition unit 84 that acquires information from the outside and updates the second frequency spectrum stored in the spectrum storage unit 81, so that the second frequency spectrum is updated to the latest state. Can be maintained. Therefore, according to the radar apparatus of the present embodiment, even when a new vehicle is sold or the shape of the vehicle is changed, whether the detected obstacle is an approach of a plurality of objects, It is possible to determine whether the object is a single object.

  As described in the first embodiment, the control voltage generation unit 1, the frequency analysis unit 6, the obstacle detection unit 7, the object superimposition determination unit 8c, the relative speed calculation unit 9, the relative distance calculation unit 10, and the error estimation unit 11 Can be composed of an electronic circuit (processing circuit). In addition, the control voltage generation unit 1, the frequency analysis unit 6, the obstacle detection unit 7, the object superimposition determination unit 8c, the relative speed calculation unit 9, the relative distance calculation unit 10, and the error estimation unit 11 execute programs stored in the memory. It can also be realized by processing with a computer (processor).

  FIG. 18 is a hardware configuration diagram when the radar apparatus of the present embodiment is configured using a dedicated processing circuit. The transmission device 301 includes an oscillator 2 and a transmission antenna 3. The receiving device 302 includes a receiving antenna 4 and a mixer 5. The processing circuit 303 includes a control voltage generation unit 1, a frequency analysis unit 6, an obstacle detection unit 7, an object superimposition determination unit 8, a relative speed calculation unit 9, a relative distance calculation unit 10, and an error estimation unit 11. And realize the function.

  FIG. 19 is a hardware configuration diagram when the radar apparatus according to the present embodiment is configured using a processor and a memory. The transmission device 301 includes an oscillator 2 and a transmission antenna 3. The receiving device 302 includes a receiving antenna 4 and a mixer 5. The processor 304 and the memory 305 include a control voltage generation unit 1, a frequency analysis unit 6, an obstacle detection unit 7, an object superposition determination unit 8, a relative speed calculation unit 9, a relative distance calculation unit 10, and an error estimation. The function with the unit 11 is realized. Note that radar devices according to other embodiments can also be realized with the same hardware configuration.

  1, 1b Control voltage generation unit, 2 oscillator, 3 transmission antenna, 4 reception antenna, 5 mixer, 6 frequency analysis unit, 7 obstacle detection unit, 8, 8b, 8c object superposition determination unit, 9 relative velocity calculation unit, 10 Relative distance calculation unit, 11 error estimation unit, 12 control unit, 13 vehicle type discrimination unit, 14 position estimation unit, 15 unnecessary wave removal unit, 16a, 16b switch, 17 reception control unit, 18 unnecessary object selection unit, 19 movement prediction unit , 20 Transmission signal control unit, 81 Spectrum storage unit, 82, 82b Spectrum comparison unit, 83 Spectrum combination unit, 84 Spectrum acquisition unit, 111 Error storage unit, 112 Error output unit, 200 External server, 301 Transmission device, 302 Reception device , 303 processing circuit, 304 processor, 305 memory.

Claims (12)

A transmission antenna for transmitting a transmission signal to the outside;
A receiving antenna for receiving a reception signal from the outside with respect to the transmission signal;
A mixer that generates a beat signal that is a difference signal between the transmission signal and the reception signal;
A frequency analyzer that performs a frequency analysis on the beat signal to calculate a first frequency spectrum;
An obstacle detection unit for detecting an obstacle from the first frequency spectrum;
An object superposition determination unit that determines whether the obstacle is a plurality of objects or a single object when the obstacle is detected by the obstacle detection unit from the first frequency spectrum;
The object superposition determination unit
A frequency spectrum that is predicted to be calculated by the frequency analysis unit when a predetermined single object exists as an obstacle, and is a frequency spectrum that reflects the uneven shape of the predetermined single object. A spectrum storage unit that stores a frequency spectrum in advance for each of the predetermined single object;
And a spectrum comparison unit that compares each of the second frequency spectrums with the first frequency spectrum to determine whether the obstacle is a plurality of objects or a single object. Radar device.   The radar apparatus according to claim 1, wherein the object superimposition determination unit includes a spectrum acquisition unit that acquires information from outside and updates the second frequency spectrum stored in the spectrum storage unit. .   The spectrum comparison unit calculates a similarity between each of the second frequency spectra and the first frequency spectrum, and when the calculated similarity is less than a predetermined threshold, The radar apparatus according to claim 1, wherein the radar apparatus determines that the object is an object.   The radar apparatus according to any one of claims 1 to 3, further comprising a relative distance calculation unit that calculates a relative distance from the first frequency spectrum to the obstacle.   Whether the obstacle is a plurality of objects or a single object compared with the first frequency spectrum after changing the intensity of the second frequency spectrum according to the relative distance. The radar apparatus according to claim 4, wherein:   The radar apparatus according to claim 4, further comprising an error estimation unit that estimates an error included in the relative distance from a determination result of the object superimposition determination unit. The error estimator is
An error storage unit that stores in advance the error included in the relative distance when the obstacle is a plurality of objects and the error included in the relative distance when the obstacle is a single object;
The radar apparatus according to claim 6, further comprising: an error output unit that outputs the error included in the relative distance according to a determination result of the object superimposition determination unit. The error storage unit stores in advance the error included in the relative distance for each analysis parameter used in the frequency analysis unit,
The radar apparatus according to claim 7, wherein the error output unit outputs the error included in the relative distance according to the analysis parameter. A position estimation unit that estimates the position of the closest object among the plurality of objects when the obstacle is a plurality of objects;
The object superimposition determination unit includes a spectrum combination unit that generates a third frequency spectrum by combining a plurality of the second frequency spectra shifted in frequency,
The spectrum comparison unit calculates a similarity between the third frequency spectrum and the first frequency spectrum to obtain a third frequency spectrum having the highest similarity;
The position estimation unit obtains a distance between the plurality of objects from a frequency shift amount between the second frequency spectrum and the third frequency spectrum having the highest similarity, and determines the distance between the obtained objects. The radar apparatus according to claim 4 or 5, wherein a position of the closest object is estimated from a distance and the relative distance.   The radar apparatus according to claim 9, wherein the spectrum combination unit generates the third frequency spectrum by combining after changing the intensity of each of the plurality of second frequency spectra.   The said spectrum comparison part calculates the similarity with the said 1st frequency spectrum, after changing the intensity | strength of the said 3rd frequency spectrum according to the said relative distance, The Claim 9 or Claim 10 characterized by the above-mentioned. The radar apparatus described. An unnecessary wave removing unit that removes unnecessary frequency components included in the beat signal;
A relative speed calculator for calculating a relative speed with the obstacle from the first frequency spectrum;
An unnecessary object selection unit that selects an unnecessary object among the plurality of objects when the obstacle is a plurality of objects;
A movement prediction unit that performs movement prediction of the unnecessary object based on the relative distance and the relative speed, and a frequency component from the unnecessary object included in the beat signal based on a movement prediction result of the movement prediction unit The transmission signal control part which controls the change per unit time of the frequency of the said transmission signal so that it may become a frequency component removed in an unnecessary wave removal part, The Claim 4 or Claim 5 characterized by the above-mentioned. Radar device.

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