Radar Equipment

Abstract

To provide a rader system capable of updating correction value even after being mounted on a movable body.SOLUTION: A rader system mounted on a movable body includes: a transmission / reception processing part 41 which is provided with a plurality of at least one of transmission antennas and receiver antennas, transmits a transmission signal from the transmission antenna, and acquires a differential signal indicating frequency difference between a reception signal received by the receiver antenna and a transmission signal; a signal processing part 42 which determines a reference value to be at least either a phase or amplitude at a predetermined reference part of a movable body according to a differential signal as a reference and determines collation value that is at least either the phase or amplitude at the reference part and corresponds to the reference value according to a differential signal to be corrected; and a correction value update part 43 which updates correction value correcting a differential signal to be corrected on the basis of the reference value and the collation value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a radar device, and more particularly to the calibration of a radar device. [Background technology]

[0002] Patent Document 1 discloses a method for calibrating a radar device. In the method disclosed in Patent Document 1, a reference target is placed in a known direction in an inspection process before shipment from the factory. Then, the direction of the reference target is measured to obtain a correction value for the reception phase difference. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4902985 Summary of the Invention [Problem to be solved by the invention]

[0004] A radar device may be mounted on a moving object such as a vehicle. It is preferable to calibrate the radar device not only when it is shipped from the factory, but also after it is mounted on the moving object. This is because it may become necessary to change the correction value due to aging of component characteristics, temperature changes, etc. However, it is not realistic to place a reference target in a known direction after the radar device is mounted on the vehicle.

[0005] The present disclosure has been made in light of the above-mentioned circumstances, and an object of the present disclosure is to provide a radar device that is capable of updating correction values ​​even after the radar device is mounted on a moving object. [Means for solving the problem]

[0006] The above object is achieved by the combination of features recited in the independent claims, and the subclaims define further advantageous specific examples. The reference characters in parentheses in the claims correspond to specific aspects described in the following embodiment as one aspect, and are not intended to limit the disclosed technical scope.

[0007] One disclosure for achieving the above object is: A transmitting antenna (24) and a receiving antenna (31), A transmission signal, which is a radio wave, is transmitted from a transmission antenna to the outside of the mobile body (1); A radar device mounted on a moving body, the radar device detecting an external object located outside the moving body by receiving, with a receiving antenna, a reception signal generated when a transmission signal is reflected outside the moving body, the radar device comprising: At least one of a plurality of transmitting antennas and a plurality of receiving antennas is provided; a transmission / reception processing unit (41) that transmits a transmission signal from a transmission antenna and acquires a differential signal indicating a frequency difference between the transmission signal and a reception signal received by a reception antenna; Use as a standard Regarding transmitting or receiving antennas A reference value, which is at least one of the phase and amplitude values ​​at a reference portion determined in advance of the moving body, is determined from the difference signal, and the reference value is set as a correction target. Regarding transmitting or receiving antennas a signal processing unit (42) that determines a reference value, which is at least one of a phase and an amplitude at a reference portion and corresponds to a reference value, from the difference signal; a correction value update unit (43) that updates a correction value for correcting at least one of the differential signal to be corrected and a transmission signal corresponding to the differential signal, based on the standard value and the reference value determined by the signal processing unit; a high-pass filter (34) through which the differential signal passes and whose cutoff frequency is variable; When acquiring a differential signal to update the correction value, the transmission / reception processing unit changes a cutoff frequency of the high-pass filter to a lower frequency side than when detecting an external object. It is a radar device. Another disclosure for achieving the above object is: A transmitting antenna (24) and a receiving antenna (31), A transmission signal, which is a radio wave, is transmitted from a transmission antenna to the outside of the mobile body (1); A radar device mounted on a moving body, the radar device detecting an external object located outside the moving body by receiving, with a receiving antenna, a reception signal generated when a transmission signal is reflected outside the moving body, the radar device comprising: At least one of a plurality of transmitting antennas and a plurality of receiving antennas is provided; a transmission / reception processing unit (41) that transmits a transmission signal from a transmission antenna and acquires a differential signal indicating a frequency difference between the transmission signal and a reception signal received by a reception antenna; a signal processing unit (42) that determines a reference value, which is at least one of the phase and amplitude at a reference portion determined in advance of the moving body, from a difference signal for a reference transmitting antenna or receiving antenna, and determines a reference value, which is at least one of the phase and amplitude at the reference portion and which corresponds to the reference value, from a difference signal for a transmitting antenna or receiving antenna to be corrected; a correction value update unit (43) that updates a correction value for correcting at least one of the differential signal to be corrected and a transmission signal corresponding to the differential signal, based on the standard value and the reference value determined by the signal processing unit; Equipped with a high-pass filter that allows the differential signal to pass and can be turned on and off, The transmission and reception processing unit is a radar device that turns off the high-pass filter when acquiring a differential signal for updating the correction value.

[0008] In this radar device, a part on the moving body is set as a reference part. At least one of the phase and amplitude of the reference part of the difference signal serving as a reference is set as a reference value, and a reference value corresponding to the reference value is also determined from the difference signal to be corrected. The correction value is updated based on the reference value and the reference value. Since the correction value is updated in this manner, it is possible to update the correction value even after the radar device is mounted on the moving body. [Brief description of the drawings]

[0009] [Figure 1] 2 is a diagram for explaining an installation position of the radar device 10 according to the embodiment. [Diagram 2] FIG. 1 shows a configuration of a radar device 10. [Diagram 3] FIG. 4 is a diagram for explaining functions executed by a control unit 40. [Figure 4] FIG. 1 is a diagram conceptually showing a change in the amplitude of a difference signal with respect to frequency. [Diagram 5] 5 is a diagram for explaining the flow of processing executed by the control unit 40 when updating a correction value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Embodiment> Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a diagram for explaining an installation position of a radar device 10 according to the embodiment. The radar device 10 is installed on a vehicle 1, which is a moving body. The vehicle 1 may run on a road and may have a bumper 2. The vehicle 1 may include a passenger car, a bus, a truck, etc.

[0011] The radar device 10 is fixed by a bracket or the like at a position slightly away from the bumper 2. The radar device 10 outputs radio waves in the millimeter wave band (for example, 79 GHz) toward the front of the vehicle 1. Hereinafter, the radio waves output by the radar device 10 are referred to as a transmission signal.

[0012] The bumper 2 in this embodiment is a front bumper. The bumper 2 is made of resin, and most of the transmission signal output by the radar device 10 passes through the bumper 2 and is output to the outside of the vehicle 1. The radar device 10 may be installed away from the bumper 2 at a position where the transmission signal passes through the bumper 2. There is no particular limit to the fixing position of the radar device 10 in the vehicle width direction. The radar device 10 may be fixed to the center of the vehicle width direction, or to the right end or left end of the vehicle width direction.

[0013] The radar device 10 outputs a transmission signal at a predetermined short period. The radar device 10 receives a signal (hereinafter, a received signal) generated when the transmission signal is reflected by an object. The radar device 10 detects the distance and direction to an external object located outside the vehicle 1 based on the received signal.

[0014] Most of the transmitted signal passes through the bumper 2. However, a portion of the transmitted signal is reflected by the bumper 2. The radar device 10 uses the received signal reflected by the bumper 2 to update a correction value used when determining the direction of an external object.

[0015] [Configuration of radar device 10] 2 shows the configuration of the radar device 10. The radar device 10 includes a transmitting unit 20, a receiving unit 30, and a control unit 40.

[0016] [Configuration of the transmitter 20] The transmitting unit 20 is a part that generates and transmits a transmission signal. The transmitting unit 20 includes a frequency synthesizer 21, a phase adjustment circuit 22, an amplifier 23, and a transmission antenna 24. The frequency synthesizer 21 generates a reference signal to be output to the phase adjustment circuit 22. The phase of the reference signal is adjusted by the phase adjustment circuit 22, and the amplitude is adjusted by the amplifier 23. The signal after the amplitude and phase adjustment is used as a transmission signal. The frequency synthesizer 21 adjusts the frequency of the reference signal. The frequency synthesizer 21 may include a voltage controlled oscillator, a phase comparator, a frequency divider, and the like. For example, the frequency synthesizer 21 generates a reference signal whose frequency repeats linear rise and fall with respect to time. This allows the radar device 10 to detect an external object using an FMCW (Frequency Modulated - Continuous Wave) method.

[0017] The range in which the frequency of the reference signal changes, i.e., the modulation bandwidth, is adjusted by the control unit 40. In the FMCW method, the larger the modulation bandwidth, the better the distance resolution. On the other hand, the smaller the time change in the frequency of the reference signal, i.e., the smaller the gradient of the chirp slope, the larger the maximum detection distance can be. In other words, there is a trade-off between distance resolution and maximum detection distance. Therefore, the modulation bandwidth is changed according to the situation.

[0018] A phase adjustment circuit 22 and an amplifier 23 are provided for each transmitting antenna 24. The radar device 10 of this embodiment has two each of the phase adjustment circuits 22, the amplifiers 23, and the transmitting antennas 24. Note that the number of transmitting antennas 24 is an example. The number of transmitting antennas 24 may be one, or three or more. The phase adjustment circuit 22 adjusts the phase of a reference signal. By adjusting the phase with the phase adjustment circuit 22, it is possible to generate a composite beam by combining the transmission signals transmitted from the two transmitting antennas 24.

[0019] The amplifier 23 amplifies the transmission signal output by the phase adjustment circuit 22. The gain of the amplifier 23 is adjusted by the control unit 40. The transmission signal whose amplitude has been amplified by the amplifier 23 is radiated as a radio wave from the transmission antenna 24. The transmission antenna 24 is, for example, a patch antenna formed on a substrate.

[0020] [Configuration of Receiving Unit 30] The receiving unit 30 includes a receiving antenna 31, a mixer 32, an amplifier 33, a variable high-pass filter 34, and an AD converter 35. The receiving antenna 31 receives a reception signal. Four receiving antennas 31 are provided. Note that the number of receiving antennas 31 is just an example. The number of receiving antennas 31 may be one, two, or three. Furthermore, the number of receiving antennas 31 may be five or more. The receiving antennas 31 can be formed on the same substrate together with the transmitting antenna 24.

[0021] The number of mixers 32, amplifiers 33, variable high-pass filters 34, and AD converters 35 provided is the same as the number of receiving antennas 31. The mixers 32 mix the received signal received by the receiving antennas 31 with a reference signal. This produces a differential signal indicating the frequency difference between the two signals. The differential signal is sometimes called a beat signal.

[0022] The amplifier 33 amplifies the differential signal. The amplifier 33 may be disposed after the variable high-pass filter 34, or another amplifier may be provided after the variable high-pass filter 34 in addition to the amplifier 33.

[0023] The variable high-pass filter 34 is a high-pass filter that can change the cutoff frequency fc. The variable high-pass filter 34 can be configured as a circuit including, for example, a variable capacitance element and a resistor. The cutoff frequency fc of the variable high-pass filter 34 is adjusted by the control unit 40. The variable high-pass filter 34 cuts off the low frequency band of the differential signal. The variable high-pass filter 34 is provided to prevent the differential signal from becoming larger than necessary. An external object located at a distance corresponding to the low frequency component cut by the variable high-pass filter 34 is not detected. The AD converter 35 converts the signal that has passed through the variable high-pass filter 34 into a digital signal and supplies it to the control unit 40.

[0024] [Configuration of control unit 40] The control unit 40 can be realized by a configuration including at least one processor. For example, the control unit 40 can be realized by a computer including a processor, a non-volatile memory, a RAM, an I / O, and a bus line connecting these components. The non-volatile memory stores a program for operating a general-purpose computer as the control unit 40. The processor executes the program stored in the non-volatile memory while utilizing the temporary storage function of the RAM, so that the control unit 40 operates as the transmission / reception processing unit 41, the signal processing unit 42, and the correction value update unit 43 shown in FIG. 3. The execution of these operations means that a control method corresponding to the above program is executed.

[0025] The control unit 40 also includes a correction value table 44. The correction value table 44 is stored in, for example, a non-volatile memory included in the control unit 40. The correction value table 44 is a table for correcting the phase and amplitude of the transmission signal and the differential signal. The correction value table 44 stores a correction value for the phase and a correction value for the amplitude for each transmission signal and differential signal. The correction value is a value for correcting the phase and amplitude for the reference transmission signal or differential signal. The differential signal is obtained for each combination of the transmission antenna 24 and the reception antenna 31. The differential signal obtained by any combination of the transmission antenna 24 and the reception antenna 31 may be used as the reference. The transmission signal may also be used as the reference for any transmission signal. The correction value of the differential signal is used when the signal processing unit 42 performs processing using the phase and amplitude of the differential signal. The correction value of the transmission signal is used to set the amplifier 23 and the phase adjustment circuit 22 at the next transmission and thereafter.

[0026] The transmission / reception processing unit 41 controls the frequency synthesizer 21, the phase adjustment circuit 22, and the amplifier 23 to transmit a transmission signal from the transmission antenna 24. The transmission / reception processing unit 41 also acquires a differential signal converted into a digital signal by the AD converter 35. During normal operation to detect an external object, the transmission / reception processing unit 41 transmits a transmission signal from one or more transmission antennas 24. For example, to realize multiple-input-multiple-output (MIMO), the transmission signal may be transmitted from two transmission antennas 24 in a time-division or simultaneous multiplexing manner. The transmission / reception processing unit 41 may also adjust the phase to beamform the transmission signals transmitted from the multiple transmission antennas 24.

[0027] The transmission / reception processing unit 41 transmits a transmission signal even during correction operation. The transmission operation during correction operation may be the same as or different from that during normal operation. As an example of making the transmission operation during correction operation different from that during normal operation, it is possible to make the modulation bandwidth wider during the transmission operation during correction operation than during normal operation.

[0028] The transmission / reception processing unit 41 adjusts the variable high-pass filter 34. During normal operation, the transmission / reception processing unit 41 sets the cutoff frequency fc of the variable high-pass filter 34 to the cutoff frequency fc when a predetermined external object is detected. The cutoff frequency fc during normal operation is a frequency that does not detect an external object present within a predetermined distance, for example, near a distance of 0 m. During reception operation during correction operation, the cutoff frequency fc is set to a frequency at which the received signal from the bumper 2 is not cut off.

[0029] FIG. 4 conceptually shows the change in amplitude of the differential signal with respect to frequency. The frequency of the differential signal has a one-to-one correspondence with the distance. Therefore, the horizontal axis in FIG. 4 is written as frequency (distance). Distance d1 is the shortest round-trip distance from the transmitting antenna 24 to the bumper 2. In this embodiment, the correction value is updated by using the portion on the inner surface of the bumper 2 corresponding to distance d1 as the reference portion.

[0030] 4 also shows the frequency characteristics of the variable high-pass filter 34 with a dashed line and a solid line. The frequency characteristics shown with a dashed line are the frequency characteristics during normal operation. The frequency characteristics shown with a solid line are the frequency characteristics during correction operation. In the frequency characteristics during normal operation, the frequency corresponding to the distance d1 is lower than the cutoff frequency fc. On the other hand, in the frequency characteristics during correction operation, the frequency corresponding to the distance d1 is higher than the cutoff frequency fc.

[0031] During normal operation, the signal processing unit 42 determines the distance to an external object based on the frequency of the differential signal. It also determines the direction of the external object from the phase difference of the differential signal corresponding to the received signals received by the two receiving antennas 31. When determining the phase difference, the phase and amplitude of the transmission signal and the differential signal are corrected by the correction value stored in the correction value table 44.

[0032] During the correction operation, the signal processing unit 42 determines the phase and amplitude of a position (i.e., a reference portion) of the bumper 2 that corresponds to the distance d1 in the reference differential signal. Also, the signal processing unit 42 determines the phase and amplitude of the reference portion from the differential signal to be corrected.

[0033] The correction value update unit 43 updates either or both of the correction values ​​for the transmission signal and the reception signal stored in the correction value table 44 as follows.

[0034] The correction value for the transmission signal is updated as follows: The phase and amplitude at the reference portion of the differential signal obtained from the transmission signal transmitted by the reference transmission antenna 24, i.e., the reception signal received by any reception antenna 31 from the reference transmission signal, are determined. This differential signal is the reference differential signal, and the phase and amplitude at the reference portion of this differential signal are the reference values.

[0035] In addition, the phase and amplitude at the reference portion of the differential signal obtained from the transmission signal transmitted by the transmitting antenna 24 to be corrected, i.e., the transmission signal to be corrected, received by the same receiving antenna 31 as the reference differential signal is determined. This differential signal is the differential signal to be corrected, and the phase and amplitude at the reference portion of this differential signal are reference values.

[0036] For example, the correction value update unit 43 updates the correction value for the phase as follows. The correction value update unit 43 sets the phase of the reference portion of the reference differential signal as a reference value, and sets the phase of the reference portion of the differential signal to be corrected as a reference value. Then, it determines the phase difference between the reference value and the reference value. The correction value for the phase stored in the correction value table 44 is a value for correcting the phase difference to θ0. In this case, the correction value is updated so that the newly calculated phase difference becomes θ0.

[0037] The correction value update unit 43 updates the correction values ​​for the amplitudes stored in the correction value table 44 as follows. The correction value update unit 43 sets the amplitude of the reference portion of the reference differential signal as a reference value, and the amplitude of the reference portion of the differential signal to be corrected as a reference value. Then, it determines the amplitude difference between the reference value and the reference value. The correction values ​​for the amplitudes stored in the correction value table 44 are values ​​for correcting the amplitude difference to A0. In this case, the correction value is updated so that the newly calculated amplitude difference becomes A0.

[0038] Next, a process for updating the correction value for the differential signal will be described. The correction value for the differential signal is updated as follows. A transmission signal transmitted from an arbitrary transmitting antenna 24 is determined to determine the phase and amplitude at a reference portion of a differential signal obtained from a received signal received by a reference receiving antenna 31. This differential signal is the reference differential signal, and the phase and amplitude of this differential signal at the reference portion are the reference values.

[0039] Furthermore, the phase and amplitude at the reference portion of the differential signal obtained from the received signal received by the receiving antenna 31 to be corrected and transmitted by the same transmitting antenna 24 as the differential signal used as the reference signal are determined. This differential signal is the differential signal to be corrected, and the phase and amplitude at the reference portion of this differential signal are the reference values. The processing after determining the reference value and reference value is the same as updating the correction value for the transmitted signal.

[0040] [Processing flow] The flow of the process executed by the control unit 40 when updating the correction value will be described with reference to FIG. 5. The initial correction value is set at the time of shipment. The process shown in FIG. 5 can be executed at any timing after the radar device 10 is mounted on the vehicle 1. The arbitrary timing is, for example, the timing when a certain period set to several months has elapsed since the process of FIG. 5 was last executed. In the following description, it is assumed that the process before FIG. 5 is started is during normal operation. It is assumed that the modulation bandwidth during normal operation is narrower than the maximum modulation bandwidth so that a distant external object can be detected.

[0041] In S1, the transmission / reception processing unit 41 switches the modulation bandwidth of the frequency synthesizer 21 to wideband modulation, which is wider than the modulation bandwidth for detecting a distant external object. The bandwidth of the wideband modulation is permitted by the Radio Law and can be the maximum bandwidth that the radar device 10 can modulate. For example, if the frequency band is 79 GHz, the modulation bandwidth of the wideband modulation can be 4 GHz.

[0042] In S2, the transmission / reception processing unit 41 sets the frequency characteristics of the variable high-pass filter 34 to those during correction operation. As a result, the cutoff frequency fc of the variable high-pass filter 34 becomes lower than the frequency corresponding to the distance to the reference location. In S3, the transmission / reception processing unit 41 transmits and receives millimeter waves.

[0043] In S4, the signal processing unit 42 determines the amplitude and phase of the reference portion for the reference differential signal and the differential signal to be corrected. Then, a correction value is calculated based on the reference value and the reference value. As described above, the reference value is the phase or amplitude of the reference portion of the reference differential signal, and the reference value is the phase or amplitude of the reference portion of the differential signal to be corrected.

[0044] In S5, the correction value update unit 43 compares the correction value calculated this time in S4 with the correction value stored in the correction value table 44. If the comparison shows a change, the process proceeds to S6. In S6, the correction value update unit 43 updates the correction value stored in the correction value table 44 to the correction value calculated this time. After S6 is executed, the process proceeds to S7. On the other hand, if the comparison in S5 shows that the correction value has not changed, the process proceeds to S7 without executing S6.

[0045] In S7, the transmission / reception processing unit 41 returns the modulation band to the modulation band during normal operation. In S8, the transmission / reception processing unit 41 returns the frequency characteristics of the variable high-pass filter 34 to the frequency characteristics during normal operation. Thereafter, the process of Fig. 5 is terminated, and normal operation is resumed.

[0046] Summary of the embodiment In the radar device 10 of the embodiment described above, a reference portion is set on the bumper 2 of the vehicle 1. At least one of the phase and amplitude of the reference differential signal at the reference portion is set as a reference value, and a reference value corresponding to the reference value is also determined from the differential signal to be corrected. The correction value is updated based on the reference value and the reference value. Since the correction value is updated in this manner, the correction value can be updated even after the radar device 10 is mounted on the vehicle 1.

[0047] During the correction operation, the transmission / reception processing unit 41 changes the frequency characteristics of the variable high-pass filter 34 to characteristics that make it easier for signals in a frequency band that is attenuated when detecting an external object to pass through. Specifically, during the correction operation, the transmission / reception processing unit 41 changes the cutoff frequency fc of the variable high-pass filter 34 to a lower frequency than during normal operation. The cutoff frequency fc of the variable high-pass filter 34 during the correction operation is a frequency lower than the frequency corresponding to the distance to the reference location. This makes the correction value less susceptible to the influence of the variable high-pass filter 34.

[0048] During the correction operation, the transmission / reception processing unit 41 makes the modulation bandwidth of the transmission signal wider than that during normal operation (S1). In the FMCW method, the distance resolution can be increased by widening the modulation bandwidth. This makes it possible to prevent the accuracy of the correction value from decreasing due to the use of a received signal from a reference location set at a position very close to the radar device 10.

[0049] Since the radar device 10 uses a portion on the inner surface of the bumper 2 as the reference portion, the correction value can be updated without being affected by changes in the external environment of the vehicle 1.

[0050] Although the embodiments have been described above, the disclosed technology is not limited to the above-described embodiments, and the following modifications are also included in the scope of the disclosure. Furthermore, various modifications other than those described below can be implemented without departing from the gist of the invention. In the following description, elements having the same reference numbers as those used up to that point are the same as the elements having the same reference numbers in the previous embodiments, unless otherwise specified. In addition, when only a portion of the configuration is described, the previously described embodiment can be applied to the other portions of the configuration.

[0051] <Variation 1> The high-pass filter may be a high-pass filter whose function can be turned on and off, instead of the variable high-pass filter 34 whose cutoff frequency fc can be changed. When this high-pass filter is turned off, signals in all frequency bands pass through without attenuation. When the correction is in operation, the frequency synthesizer 21 turns off the high-pass filter. Even in this way, the correction value is less susceptible to the influence of the high-pass filter.

[0052] <Variation 2> In the embodiment, the reference portion is set on the inner surface of the bumper 2. However, the reference portion is not limited to the bumper 2. The reference portion may be a portion on a part of the vehicle 1 or an attachment added to the vehicle 1, as long as the radar device 10 can transmit and receive signals. For example, a radio wave reflector may be disposed on the inner surface of the bumper 2, and a portion on the radio wave reflector may be set as the reference portion. For example, a small corner reflector may be used as the radio wave reflector. The radio wave reflector may be disposed in a position where signals can be transmitted and received, but is preferably disposed near the boundary of the field of view so as not to interfere with the detection of external objects.

[0053] <Modification 3> The distance d1 is the distance over which the millimeter wave is reflected once at the reference location. However, the signal processor 42 may determine the standard value and the reference value using a differential signal that is multiple-reflected between the reference location and the radar device 10. In this way, even if the distance to the reference location is short, the possibility that the phase and amplitude of the reference location cannot be detected in the differential signal is reduced.

[0054] <Modification 4> As described in the embodiment, the numbers of transmitting antennas 24 and receiving antennas 31 are not limited to those shown in Fig. 2. However, there may be a plurality of transmitting antennas 24 and a plurality of receiving antennas 31. This is because when there is only one transmitting antenna 24 and one receiving antenna 31, there is only a reference differential signal, and no differential signal to be corrected.

[0055] <Variation 5> In the embodiment, the phase and the amplitude are corrected, but it is also possible to correct only either the phase or the amplitude. [Explanation of symbols]

[0056] 1: Vehicle 2: Bumper 10: Radar device 20: Transmitter 21: Frequency synthesizer 22: Phase adjustment circuit 23: Amplifier 24: Transmitting antenna 30: Receiver 31: Receiving antenna 32: Mixer 33: Amplifier 34: Variable high-pass filter 35: AD converter 40: Control unit 41: Transmitting / receiving processing unit 42: Signal processing unit 43: Correction value update unit 44: Correction value table

Claims

1. A transmitting antenna (24) and a receiving antenna (31), A transmission signal, which is a radio wave, is transmitted from the transmission antenna to the outside of the mobile body (1); A radar device mounted on a moving body, the radar device detecting an external object located outside the moving body by receiving, with the receiving antenna, a reception signal generated when the transmission signal is reflected outside the moving body, the radar device comprising: At least one of the transmitting antennas and the receiving antennas is provided in plurality, a transmission / reception processing unit (41) that transmits the transmission signal from the transmission antenna and acquires a differential signal indicating a frequency difference between the reception signal received by the reception antenna and the transmission signal; a signal processing unit (42) that determines a reference value, which is at least one of a phase and an amplitude at a reference portion determined in advance of the moving body, from the difference signal for the transmitting antenna or the receiving antenna that is a reference, and determines a reference value, which is at least one of a phase and an amplitude at the reference portion and a value corresponding to the reference value, from the difference signal for the transmitting antenna or the receiving antenna that is a correction target; a correction value update unit (43) that updates a correction value for correcting at least one of the differential signal to be corrected and the transmission signal corresponding to the differential signal based on the standard value and the reference value determined by the signal processing unit; a high-pass filter (34) through which the difference signal passes and whose cut-off frequency is variable; When acquiring the differential signal to update the correction value, the transmission / reception processing unit changes the cutoff frequency of the high-pass filter to a lower frequency side than when detecting the external object.

2. A transmitting antenna (24) and a receiving antenna (31), A transmission signal, which is a radio wave, is transmitted from the transmission antenna to the outside of the mobile body (1); A radar device mounted on a moving body, the radar device detecting an external object located outside the moving body by receiving, with the receiving antenna, a reception signal generated when the transmission signal is reflected outside the moving body, the radar device comprising: At least one of the transmitting antennas and the receiving antennas is provided in plurality, a transmission / reception processing unit (41) that transmits the transmission signal from the transmission antenna and acquires a differential signal indicating a frequency difference between the reception signal received by the reception antenna and the transmission signal; a signal processing unit (42) that determines a reference value, which is at least one of a phase and an amplitude at a reference portion determined in advance of the moving body, from the difference signal for the transmitting antenna or the receiving antenna that is a reference, and determines a reference value, which is at least one of a phase and an amplitude at the reference portion and a value corresponding to the reference value, from the difference signal for the transmitting antenna or the receiving antenna that is a correction target; a correction value update unit (43) that updates a correction value for correcting at least one of the differential signal to be corrected and the transmission signal corresponding to the differential signal based on the standard value and the reference value determined by the signal processing unit; a high-pass filter that can be turned on and off and through which the differential signal passes; The transmission / reception processing unit turns off the high-pass filter when acquiring the differential signal for updating the correction value.

3. The radar device according to claim 1 or 2, The radar device, wherein the transmission / reception processing unit, when acquiring the differential signal to update the correction value, sets a modulation bandwidth of the transmission signal to be wider than that when detecting the external object.

4. The radar device according to any one of claims 1 to 3, The moving object is a vehicle (1) equipped with a bumper (2), the radar device is installed at a position where the transmission signal passes through the bumper, A radar device, wherein the reference portion is a portion of the bumper to which the transmission signal is irradiated.

5. The radar device according to any one of claims 1 to 3, The moving object is a vehicle (1) equipped with a bumper (2), A radio wave reflector is disposed on the inner surface of the bumper, A radar device, wherein the reference portion is the radio wave reflector.

6. The radar device according to claim 4 or 5, The signal processing unit determines the standard value and the reference value by using the differential signal that is multiply reflected between the reference portion and the radar device.

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