JP2016156754A - Radar device and target detection method employed thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably remove interference waves using a simple circuit configuration.SOLUTION: A radar device includes; setting means (control unit 11) that sets up the radar device such that at least some cycle periods of the pulse signal are different from others; detection means (distance/velocity detection unit 16-1) configured to detect distance to a target object identified by the pulse signal; and removal means (interference wave removal unit 16-2) configured to remove the target object as an interference wave from other radar devices when there is a difference between a distance to the target object detected by the detection means during the above mentioned different cycle periods and a distance to the target object detected in other cycle periods.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radar apparatus and an object detection method for the radar apparatus.

  In general, a radar apparatus detects position information such as a distance to an object and speed information and velocity information by radiating a radio wave and receiving and processing a reflected wave reflected by the object.

  In such a radar apparatus, it is necessary to avoid interference between a reflected wave radiated by itself and reflected by an object and a radio wave radiated from another radar apparatus. When the other radar device as a source is a similar radar device, it is not easy to avoid interference.

  As means for avoiding such mutual interference, FMCW (Frequency Modulated Continuous Wave) radar is known to prevent interference by controlling the period, transmission interval, and modulation gradient of an FMCW modulated signal.

  In pulse radar, a method for preventing interference by controlling the turning direction of circularly polarized waves as shown in Patent Document 1, or a technique for stopping transmission and operating only a receiving circuit as shown in Patent Document 2. There is known a method of receiving radio waves, accumulating received signals as unnecessary signals in a storage unit, performing normal measurement, and removing unnecessary signals therefrom.

  In general, as a technique for removing clutter in a pulse radar, a composite pulse radar that transmits a plurality of transmission pulses during one transmission / reception repetition period as shown in Patent Document 3 transmits each transmission / reception repetition period. When changing the time interval between pulses, that is, changing the pulse repetition frequency (PRF) and observing a series of target reflected reception signals based on the timing of any of the transmission pulses in the transmission pulse, every repetition period For example, a method of removing a target reflected reception signal appearing at different time positions by an asynchronous signal removal processing circuit is known.

Japanese Utility Model Publication No. 09-3656290 JP 2010-216824 A Japanese Patent Laid-Open No. 61-133895

  By the way, since the technique disclosed in Patent Document 1 uses circular polarization, a device for shifting the phase of the transmission radio wave by 90 degrees is necessary, and the structure of the antenna is compared with that of a single polarization antenna. There are problems such as complexity.

  In addition, since the technique shown in Patent Document 2 requires a storage unit, it is disadvantageous in terms of size and cost, and when a radar signal serving as an interference source is removed, a true target signal is removed as an unnecessary signal. There is a problem that it may be.

  Furthermore, the technique shown in Patent Document 3 has a problem that interference cannot be recognized when a radar apparatus having a PRF similar to that of itself is an interference source.

  The present invention has been made in view of the above points, and provides a radar apparatus and a radar apparatus target detection method capable of reliably removing interference from other radar apparatuses with a simple circuit configuration. The purpose is to do.

In order to solve the above problems, the present invention provides a radar apparatus that detects a target object by transmitting a pulse signal at a predetermined repetition period and receiving and analyzing the pulse signal reflected by the target object. Detecting at different repetition periods by setting means for setting at least a part of the repetition period of the pulse signal to be different, detection means for detecting a distance to the object specified by the pulse signal, and the detection means Removing means for removing the target object as an interference wave from another radar apparatus when the distance to the target object is different from the distance to the target object detected in other repetition periods. It is characterized by that.
According to such a configuration, it is possible to reliably remove interference from other radar devices with a simple circuit configuration.

Further, the present invention is characterized in that the setting means sets so that at least one repetition period of a plurality of pulse signals existing within a sampling period is different.
According to such a configuration, the interference wave can be reliably removed with a simple circuit configuration, and the sampling period can be made constant, so that it is possible to prevent the occurrence of speed uncertainty.

Also, the present invention is characterized in that the setting means sets so that all the repetition cycles of a plurality of pulse signals existing within a sampling cycle are different.
According to such a configuration, the interference wave can be more reliably removed.

According to the present invention, the setting means sets a repetition cycle in units of a pulse signal that is repeated a predetermined number of times with the same repetition cycle, and the repetition cycle of at least some of the plurality of units is different. It is characterized by setting.
According to such a configuration, the interference wave can be reliably removed with a simple circuit configuration, and the sampling period can be made constant, so that it is possible to prevent the occurrence of speed uncertainty.

In the present invention, the setting means determines that an interference source exists when a received signal is present in a state where transmission of the pulse signal is stopped, and repeats the repetition so that the removal means can remove the interference signal. The period is set.
According to such a configuration, it is possible to reliably detect the presence of an interference wave.

Further, the present invention is characterized in that the removing means relatively reduces the interference wave component by averaging the detection signals in different repetition periods and the detection signals in other repetition periods.
According to such a configuration, the interference wave component can be reliably removed with a simple configuration.

Further, the present invention is characterized in that the removing means removes a detection signal only in a predetermined repetition period as an interference wave component.
According to such a configuration, the interference wave component can be reliably removed with a simple configuration.

Further, the present invention provides an object detection method for a radar device that detects a target object by transmitting a pulse signal at a predetermined repetition period and receiving and analyzing the pulse signal reflected by the target object. In the setting step for setting at least a part of the repetition period of the pulse signal to be different, the detection step for detecting the distance to the object specified by the pulse signal, and the detection step, detection is performed at different repetition periods. A removal step of removing the target object as an interference wave from another radar device when the distance to the target object differs from the distance to the target object detected in other repetition cycles. It is characterized by.
According to such a method, it is possible to reliably remove interference from other radar devices with a simple circuit configuration.

  According to the present invention, it is possible to provide a radar apparatus and an object detection method for a radar apparatus that can reliably remove interference waves with a simple circuit configuration.

It is a figure which shows the structural example of the radar apparatus which concerns on embodiment of this invention. It is a figure explaining operation | movement of embodiment shown in FIG. It is a figure explaining operation | movement of embodiment shown in FIG. It is a flowchart explaining the detail of operation | movement of embodiment shown in FIG. 5 is a flowchart for explaining details of an “interference detection process” shown in FIG. 4. It is a figure which shows the deformation | transformation embodiment of this invention.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of Embodiment of the Present Invention FIG. 1 is a block diagram illustrating a configuration example of a radar apparatus according to an embodiment of the present invention. As shown in FIG. 1, the radar apparatus according to the embodiment of the present invention includes a transmission antenna TX, reception antennas RX1 to RX4, a control unit 11, a transmission unit 12, an oscillation unit 13, a reception unit group 14, an A / D (Analog). to Digital) conversion unit group 15 and signal processing unit 16 are the main components. The radar apparatus according to the present embodiment will be described as an example in which the radar apparatus is mounted on a vehicle such as an automobile and operates as an apparatus that detects other vehicles, obstacles, pedestrians, and the like. Of course, it is possible to equip a moving body other than the vehicle.

  Here, the transmission antenna TX is an antenna that transmits a pulse signal supplied from the transmission unit 12 as a radio wave toward an object. The receiving antennas RX1 to RX4 are antennas that receive a radio wave transmitted from the transmitting antenna TX and reflected by the object and supply the received signal to the receiving unit group 14 as an electrical signal.

  The control unit 11 controls the transmission unit 12 to transmit a pulse signal at a predetermined timing, controls the reception unit group 14, and receives the signals received by the reception antennas RX1 to RX4 to the A / D conversion unit group 15. Supply.

  The transmission unit 12 modulates the high frequency signal supplied from the oscillation unit 13 under the control of the control unit 11, generates a high frequency pulse signal, and radiates it to the space via the transmission antenna TX.

  The oscillating unit 13 oscillates at a predetermined frequency, and supplies the obtained high frequency signal (local signal) to the receiving unit group 14 and the transmitting unit 12.

  The reception unit group 14 includes reception units 14-1 to 14-4, and demodulates the reception signals supplied from the reception antennas RX1 to RX4 with the high-frequency signal supplied from the oscillation unit 13, and the A / D conversion unit Supply to group 15.

  The A / D conversion unit group 15 includes A / D conversion units 15-1 to 15-4, and samples signals supplied from the reception units 14-1 to 14-4 at a predetermined period. The digital signal is converted by / D conversion and supplied to the signal processing unit 16.

  The signal processing unit 16 includes a distance / speed detection unit 16-1 and an interference wave removal unit 16-2. The distance / speed detection unit 16-1 performs processing such as presum processing and DFT (Discrete Fourier Transform) on the digital signal supplied from the A / D conversion unit 15, performs speed detection of the received signal, An object is detected from information on the Doppler frequency of the object and information on the distance. The interference wave removal unit 16-2 executes a process of removing the interference wave from the object detection information supplied from the distance / speed detection unit 16-1.

(B) Description of Operation of the Embodiment of the Present Invention Next, the operation of the embodiment of the present invention will be described. FIG. 2 is a timing chart for explaining the operation of the embodiment shown in FIG. In FIG. 2, the horizontal axis indicates time, TX on the vertical axis indicates a pulse signal transmitted from the transmission antenna TX, and RX1 to RX4 indicate pulse signals received by the reception antennas RX1 to RX4. Further, the radar apparatus A represents the radar apparatus shown in FIG. 1, and the radar apparatus B represents another radar apparatus that is a source of interference waves.

  For example, when an ignition key of a vehicle on which the radar apparatus shown in FIG. 1 is mounted is turned on, an ECU (Electric Control Unit) (not shown) operates with respect to the control unit 11 of the radar apparatus shown in FIG. Instruct to start. As a result, the control unit 11 controls the transmission unit 12 so as to transmit the pulse signal at a predetermined cycle, and also controls the reception unit group 14 to transmit the reflected wave to any of the reception units 14-1 to 14-4. It is controlled to receive depending on. More specifically, as illustrated in FIG. 2, the control unit 11 controls the transmission unit 12 to transmit a transmission pulse (pulse indicated by a thick solid line arrow in FIG. 2) at the timing t <b> 1 and also receives the reception unit 14. -1. When a pulse repetition period T1 (= 400 ns) elapses after the transmission pulse is transmitted, the control unit 11 controls the transmission unit 12 to transmit the transmission pulse and activate the reception unit 14-2 at timing t2. . Further, when the pulse repetition period T2 (= 450 ns) has elapsed after the transmission pulse is transmitted, the control unit 11 controls the transmission unit 12 to transmit the transmission pulse at timing t3, and the reception unit 14-3 is activated. Make it work. Similarly, when a pulse repetition period T3 (= 500 ns) has elapsed since the transmission pulse was transmitted, the control unit 11 controls the transmission unit 12 to transmit the transmission pulse at timing t4 and also receives the reception unit 14-4. To work. Then, when a pulse repetition period T4 (= 550 ns) has elapsed since the transmission pulse was transmitted, the control unit 11 controls the transmission unit 12 to transmit the transmission pulse at timing t5, and the reception unit 14-1 After that, after the pulse repetition period T1 (= 400 ns) has elapsed, the transmission pulse is transmitted and the reception unit 14-1 is operated, and after the pulse repetition period T2 (= 450 ns) has elapsed, the transmission pulse is transmitted and received. The operation of operating the unit 14-2 is repeated. As a result, as shown in FIG. 2, the pulse signal is transmitted in the pulse repetition periods T1 to T4.

  The transmission pulse transmitted from the transmission antenna TX at the timing t1 is reflected by the object, received by the reception antenna RX1, and supplied to the reception unit 14-1. Assuming that the time from when the transmission pulse is transmitted, reflected by the object, and received by the receiving antenna RX1 is RTa, as shown in FIG. 2, the echo Rα is received after the time RTa after the transmission pulse is transmitted. . Since the pulse repetition period is very short (several hundred ns), the distance between the vehicle on which the radar device is mounted and the object hardly changes during that period. The echo Rα is received after the elapse of time RTa from the transmission.

  The reception units 14-1 to 14-4 demodulate the reception signals supplied from the reception antennas RX1 to RX4 with the high-frequency signals supplied from the oscillation unit 13 and output the reception pulses. The A / D converters 15-1 to 15-4 convert the demodulated signals respectively supplied from the receivers 14-1 to 14-4 into digital signals and output the digital signals. The distance / speed detection unit 16-1 performs integration processing, DFT processing, and the like on the digital signals supplied from the A / D conversion units 15-1 to 15-4, and detects the distance and speed of the object. And after performing the process (it mentions later for details) which removes an interference wave by the interference wave removal part 16-2, it outputs as target information.

  By the way, when the radar apparatus B as an interference source exists, the radar apparatus A receives the pulse signal transmitted from the radar apparatus B. For example, as shown in FIG. 2, when the radar apparatus B transmits a pulse signal at a timing indicated by a thick dashed arrow, the radar apparatus A sets the pulse signal transmitted from the radar apparatus B to a distance from the radar apparatus B. The received signal Rβ is received at a timing delayed by the corresponding time RTb. Such a received signal Rβ needs to be removed because it may be erroneously detected as a reflected wave from the object.

  In the example shown in FIG. 2, the pulse repetition periods T1 to T4 of the radar apparatus B are 550 ns, 500 ns, 450 ns, and 400 ns, which are different from the pulse repetition periods of the radar apparatus A. In such a case, as shown in the broken-line rectangle in FIG. 2, the received signal from the radar apparatus B (the signal indicated by the broken-line arrow in FIG. 2) appears at a different distance for each pulse repetition period, The signal from the true detection object always appears at a certain distance.

  Therefore, in the present embodiment, among the received signals, signals having different distances for each pulse repetition period are determined to be interference waves from the interference source, and the interference wave removing unit 16-2 removes them. More specifically, the interference wave removal unit 16-2 averages the signals of each pulse repetition period. Thus, while a constant value is maintained for the reflected signal from the true detection target, the value for the interference wave is reduced by averaging, so that the interference wave can be removed.

  2 shows an example in which the pulse repetition period is different between the radar apparatus A and the radar apparatus B. When the pulse repetition period is the same between the radar apparatus A and the radar apparatus B, the state shown in FIG. 3 is obtained. . In the example of FIG. 3, the pulse repetition periods T1 to T4 of the radar apparatus A and the radar apparatus B are 400 ns, 450 ns, 500 ns, and 550 ns, and the transmission timings also match in this example. When the pulse repetition period is the same, as shown in the rectangular broken line, the reflected wave and the interference wave from the true detection target appear at the same distance. Therefore, the interference wave cannot be removed by averaging. .

  Therefore, in the present embodiment, transmission of a pulse signal is temporarily stopped, and when a reception signal exists at that time, it is determined that an interference source exists. If an interference wave exists, a pulse signal is transmitted at a predetermined pulse repetition period, and the received signal is in the state of FIG. 2 (hereinafter referred to as “first state”), or the state of FIG. (Hereinafter referred to as “second state”). In the first state, since the pulse repetition cycle of the interference source and the pulse repetition cycle of the own apparatus are different, the interference wave can be removed by the above-described processing, and the processing is continued as it is. On the other hand, since the interference wave cannot be removed in the second state shown in FIG. 3, in this case, the first state is set by changing the setting of the pulse repetition period. More specifically, the first state is set by changing the arrangement order of the pulse repetition periods or changing the length of each pulse repetition period. Whether or not the first state has been reached can be determined by transmitting a pulse signal and determining whether or not the distance of the interference wave included in the received signal changes. And when it will be in a 1st state, it transfers to normal operation | movement.

  As described above, according to the embodiment of the present invention, when an object having a different distance for each pulse repetition period is detected, an interference wave from an interference source is detected. Therefore, for example, it is possible to prevent a transmission pulse from another radar apparatus mounted on the host vehicle or another vehicle from being erroneously detected as an object. In addition, when the transmission of the pulse signal is stopped and the reception signal is present at that time, it is determined that the interference source is present, and by changing the pulse repetition period, the first state is obtained. It is possible to reliably prevent the influence from the same type of radar apparatus.

  Next, details of processing executed in the embodiment shown in FIG. 1 will be described with reference to FIG. When the process shown in FIG. 4 is started, the following steps are executed.

  In step S10, the control unit 11 assigns an initial value 1 to a variable i for counting the number of processes.

  In step S11, the control unit 11 operates the reception unit 14-i. For example, when i = 1, the receiving unit 14-1 is operated.

  In step S12, the control unit 11 controls the transmission unit 12 to transmit a transmission pulse. For example, when the current time is timing t1, a transmission pulse is transmitted at timing t1, as shown in FIG.

  In step S13, the reception unit 14-i receives the pulse signal reflected by the object. For example, when i = 1, a pulse signal transmitted from the transmission antenna TX and reflected by the object is received by the antenna RX1 and supplied to the reception unit 14-1.

  In step S14, the received pulse signal is supplied to the subsequent circuit. For example, when i = 1, the receiving unit 14-1 demodulates the signal supplied from the receiving antenna RX1 with the high frequency signal supplied from the oscillating unit 13, and supplies the demodulated signal to the A / D converting unit 15-1. . The A / D conversion unit 15-1 converts the supplied signal into a digital signal by A / D conversion, and supplies the digital signal to the distance / speed detection unit 16-1.

  In step S15, the control unit 11 determines whether or not the pulse repetition period Ti has elapsed. If it is determined that Ti has elapsed (step S15: Yes), the control unit 11 proceeds to step S16, and otherwise (step S15). In step S15: No), the process returns to step S13 to repeat the same process as described above. For example, if i = 1, the process returns to step S13 and the same process is repeated until the pulse repetition period T1 shown in FIG. 2 elapses. Note that the pulse repetition period can be stored in a semiconductor memory device, for example, and a period corresponding to the variable i can be acquired from the semiconductor memory device and determined based on this period.

  In step S16, the control unit 11 increments the value of the variable i for counting the number of processings by one.

  In step S17, the control unit 11 determines whether or not the value of the variable i is greater than 4, the process proceeds to step S18 if greater than 4 (step S17: Yes), and otherwise (step S17: No). ) Returns to step S11 and repeats the same process as described above.

  In step S18, the control unit 11 determines whether or not the processing for one point of DFT has been completed. When the processing for one point has been completed (step S18: Yes), the process proceeds to step S19, and otherwise In this case (step S18: No), the process returns to step S10 and the same process as described above is repeated. For example, when one point of DFT is composed of 16 pieces of data, it can be determined by whether or not the processing of steps S10 to S18 has been repeated 16 times.

  In step S19, the control unit 11 determines whether or not the processing for all points of the DFT has been completed. If the processing for all points has been completed (step S19: Yes), the process proceeds to step S20. In this case (step S19: No), the process returns to step S10 and the same process as described above is repeated. For example, when all the points of the DFT are composed of 32 pieces of data for one point, it can be determined whether or not the processes of steps S10 to S19 are repeated 32 times. In addition, you may make it determine by the process of step S18 and step S19 collectively.

  In step S20, the distance / speed detector 16-1 performs DFT processing on the signals received by the receiving antennas RX1 to RX4. More specifically, the distance / speed detection unit 16-1 performs DFT processing after integrating the received signal (presum processing).

  In step S <b> 21, the distance / speed detection unit 16-1 executes a process for detecting the distance and speed of the object on the data obtained by the DFT process. Information regarding the distance and speed of the object detected in this way is supplied to the interference wave removing unit 16-2.

  In step S22, the interference wave removal unit 16-2 performs a process of removing the interference wave. For example, the interference wave removal unit 16-2 adds and averages the signals received by the antennas RX1 to RX4 and subjected to the DFT processing. As a result, the echo from the true detection target does not decrease by averaging, but the value of the interference wave decreases. Therefore, the obtained value is compared with the threshold, and the target below the threshold is removed. Thus, the interference wave can be removed.

  In step S23, the control unit 11 determines whether or not to execute the interference detection process, and when it is determined to execute (step S23: Yes), the process proceeds to step S24, and otherwise (step S23: No). Then, the process proceeds to step S25. As will be described later, the interference detection process determines whether or not an interference source exists, and if it exists, enters the first state (a state in which interference waves can be removed) shown in FIG. It is a process to set. Note that, as a criterion for determining whether or not to perform the interference detection process, for example, it can be determined based on whether or not a predetermined time has elapsed since the previous execution.

  In step S24, the control unit 11 executes interference detection processing. Details of this processing will be described later with reference to FIG.

  In step S25, the control unit 11 determines whether or not to continue the process. When it is determined that the process is to be continued (step S25: Yes), the control unit 11 returns to step S10 and executes the same process as described above. In other cases (step S25: No), the process ends.

  Next, the details of the “interference detection process” shown in FIG. 4 will be described with reference to FIG. When the process shown in FIG. 5 is started, the following steps are executed.

  In step S50, the control unit 11 controls the transmission unit 12 to stop the transmission operation. As a result, transmission of the pulse signal from the transmission antenna TX is stopped.

  In step S51, the control unit 11 controls the reception unit group 14 to execute reception processing. As a result, when an interference source exists, a transmission signal from the interference source is received.

  In step S52, the control unit 11 determines whether or not a reception signal is detected by the reception process in step S51. If it is determined that the reception signal is detected (step S52: Yes), the process proceeds to step S53. In other cases (step S52: No), the process returns (returns) to the original process.

  In step S53, the control unit 11 controls the transmission unit 12 to transmit a pulse signal, for example, at the currently set pulse repetition period. As a result, a pulse signal is transmitted from the transmission antenna TX. For example, a pulse signal is transmitted based on pulse repetition periods T1 to T4 shown in FIG.

  In step S54, the control unit 11 controls the reception unit group 14 to execute reception processing. For example, a pulse signal is received by the receiving unit group 14 based on the pulse repetition periods T1 to T4 shown in FIG.

  In step S55, the control unit 11 detects the reception state. More specifically, the control unit 11 inquires of the signal processing unit 16 about the reception state, and specifies whether the reception state is the first state or the second state.

  In step S56, the control unit 11 determines whether or not the reception state is the second state. If it is determined that the reception state is the second state (the state of FIG. 3) (step S56: Yes), the process proceeds to step S57. In other cases, the process returns (returns) to the original process. For example, if it is determined that the state is the second state, the process proceeds to step S57.

  In step S57, the control part 11 performs the process which changes pulse repetition T1-T4. For example, a process of changing the order of the pulse repetitions T1 to T4 or changing the length of each pulse repetition period is executed. The pulse repetition period changed in this way is stored in, for example, a semiconductor memory device. And it returns to the process of step S53 and repeats the process similar to the above-mentioned case.

  According to the process shown in FIG. 5, when the transmission operation is stopped and the received signal is present, it is determined that the interference source is present, and the first state (shown in FIG. 2) in which the interference wave can be removed. The pulse repetition period can be appropriately set so that

(C) Description of Modified Embodiment It goes without saying that the above embodiment is merely an example, and the present invention is not limited to the case described above. For example, in the above embodiment, the pulse repetition period is set to four types of T1 to T4, but may be set to three types or less or five types or more.

  In the above embodiment, the pulse repetition periods T1 to T4 are all set to be different from each other. However, at least one pulse repetition period may be set to be different from the others. Of course, when all are different, the value is reduced by averaging, but detection is possible even when only one is different. When one pulse repetition period is different, the distance of the signal detected after the pulse signal transmitted at different timing becomes different from the other, so the interference wave is removed by detecting such a signal. can do.

  In the above embodiment, the pulse repetition periods T1 to T4 are set so that the periods become longer in this order, but may be set so that the periods become shorter in this order. In addition, they may be arranged randomly rather than in the long or short order.

  The difference value of the length of the pulse repetition periods T1 to T4 may be set to a difference value at which the amount of interference wave movement is equal to or greater than the detection limit. For example, taking T1 and T2 as an example, when | T1−T2 | = ΔT, T1 and T2 may be set so that ΔT is equal to or greater than the detection limit of the radar apparatus. The same applies to T3 and T4.

  In the embodiment shown in FIG. 1, the receiving antennas RX <b> 1 to RX <b> 4 are provided, but the number may be other than this. For example, you may make it have only one. In the embodiment shown in FIG. 1, the four receiving units 14-1 to 14-4 are provided. However, as shown in FIG. 6, the four receiving antennas are switched and used by the received signal switching unit 10. You may do it. In the embodiment shown in FIG. 6, there are four reception antennas RX1 to RX4, one reception unit 14-1 and one A / D conversion unit 15, and the reception signal switching unit 10 is controlled by the control unit 11. The reception signal is supplied to the reception unit 14 by controlling and selecting any of the reception antennas RX1 to RX4. Even with such a configuration, the interference wave can be removed.

  In the example shown in FIG. 2, the pulse repetition period is set in the order of T1, T2, T3, and T4. For example, when T1 is repeatedly executed a predetermined number of times (the number of integrations) and T1 ends. May execute T2 in the same manner, and then execute T3 and T4 in the same manner. Even with such a method, interference waves can be removed.

  Further, in the above embodiment, the interference wave is reduced by averaging the signals of different pulse repetition periods, compared with the signal from the true detection target. For example, data of the DFT processing result When there is a data mismatch between the receiving antennas (for example, when the receiving antenna RX1 has a received wave at a predetermined position but the receiving antennas RX2 to RX4 do not have the same position) Alternatively, the received wave may be removed as an interference wave.

TX transmitting antenna RX1 to RX4 receiving antenna 10 received signal switching unit 11 control unit (setting means)
DESCRIPTION OF SYMBOLS 12 Transmission part 13 Oscillation part 14 Reception part group 14-1 to 14-4 Reception part 15 A / D conversion part group 15-1 to 15-4 A / D conversion part 16 Signal processing part 16-1 Distance and speed detection part (Detection means)
16-2 Interference wave removing unit (removing means)

Claims (8)

In a radar apparatus that detects a target object by transmitting a pulse signal at a predetermined repetition period and receiving and analyzing the pulse signal reflected by the target object,
Setting means for setting at least a part of the repetition period of the pulse signal to be different;
Detecting means for detecting a distance to the object specified by the pulse signal;
When the distance to the object detected in the different repetition period differs from the distance to the object detected in the other repetition period by the detection means, the object is caused to interfere with another radar apparatus. Removing means for removing as waves,
A radar apparatus comprising:   The radar apparatus according to claim 1, wherein the setting means sets so that at least one repetition period of a plurality of pulse signals existing within a sampling period is different.   The radar apparatus according to claim 2, wherein the setting unit sets all the repetition cycles of the plurality of pulse signals existing within the sampling cycle to be different.   The setting means is characterized in that the repetition cycle is set in units of a pulse signal that is continuous a predetermined number of times with the same repetition cycle, and the repetition cycle of at least some of the plurality of units is set to be different. The radar apparatus according to claim 1.   The setting means determines that an interference source is present when a received signal is present in a state where transmission of a pulse signal is stopped, and sets the repetition period so that the removal means can remove the interference source. The radar apparatus according to any one of claims 1 to 4, wherein the radar apparatus is characterized in that:   The said removal means averages the detection signal in a different repetition period, and the detection signal in the other repetition period, and makes an interference wave component relatively small, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The radar device according to item.   The radar device according to claim 1, wherein the removing unit removes a detection signal only in a predetermined repetition period as an interference wave component. In the object detection method of the radar apparatus for detecting the object by transmitting a pulse signal at a predetermined repetition period and receiving and analyzing the pulse signal reflected by the object,
A setting step for setting at least a part of the repetition period of the pulse signal to be different;
A detection step of detecting a distance to an object specified by the pulse signal;
In the detection step, when the distance to the object detected in a different repetition period and the distance to the object detected in another repetition period are different, the object is interfered with by another radar device. A removal step to remove as a wave;
A method for detecting an object of a radar apparatus, comprising:

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