JP2009128016A - Radar system, its control method, and radar control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar system having high detection accuracy and capable of shortening detection time and provide a radar control apparatus and a method for controlling radar systems. <P>SOLUTION: The present invention relates to the radar system, the radar control apparatus, and the method for controlling radar systems. The radar system is provided with a plurality of antennas 22 for receiving radar waves; a detection means 14 for detecting objects at a plurality of detection angles through the use of beat signals acquired by each of the plurality of antennas 22; and a computation means 16 for selecting an object for computation from among the objects detected by the detection means 14 and altering the interval between some detection angles among a plurality of detection angles at which the detection means 14 detects objects in such a way as to be different from the intervals of the other detection angles on the basis of positional information of the object for computation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radar device, a radar control device, and a radar device control method, and more particularly to a radar device, a radar control device, and a radar that detect an object at a plurality of detection angles using beat signals obtained from a plurality of antennas. The present invention relates to an apparatus control method.

  A radar device using millimeter waves is used as a radar device for vehicles, for example. The following systems are used as radar systems using millimeter waves. Using a frequency-modulated continuous wave (FM-CW) as a transmission wave, a beat signal is obtained from the transmission wave and the reception wave. An object at a plurality of detection angles is detected using beat signals of a plurality of antennas. As a method of detecting an object at a plurality of detection angles, for example, there is a method of performing digital beam forming (DBF) processing.

  Thus, the following techniques are disclosed in the radar apparatus that detects an object at a detection angle using a beat signal. Patent Document 1 discloses a technique for setting an initial value of an analysis operation when detecting the orientation of an object by an analysis operation using an adaptive array antenna filter based on a recognition result of digital beamforming. Patent Document 2 discloses a technique in which a scanning step angle of digital beam forming for detecting an object at a long distance is smaller than a scanning step angle of digital beam forming for detecting an object at a short distance. Yes. Patent Document 3 discloses a technique using two radar devices.

Patent Document 4 describes that, based on information obtained in the previous detection cycle, a detected object predicts a peak that should occur on the distance power spectrum. Patent Document 5 discloses a technique for estimating a beat frequency and an angle related to an object from a history of object information that has already been acquired.

JP 2001-221842 A JP 2001-235540 A JP 2006-46962 A JP 2003-270341 A JP 2002-257925 A

  When detecting the object at the detection angle, the detection accuracy of the object can be improved by reducing the interval between the detection angles. However, if the detection angle interval is reduced, for example, the calculation time of the digital beam forming process becomes longer, and it takes time to detect the object.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a radar device, a radar control device, and a radar device control method that have high detection accuracy and can reduce the detection time.

  The present invention relates to a plurality of antennas for receiving radar waves, detection means for detecting an object at a plurality of detection angles using beat signals obtained for each of the plurality of antennas, and an object detected by the detection means. The calculation object is selected from the calculation object, and based on the position information of the calculation object, the detection means detects the interval between some detection angles among the plurality of detection angles at which the detection object is detected next. And a computing unit that changes the distance so as to be different from the interval. According to the present invention, the interval between the detection angles can be varied depending on the position information of the calculation object. Therefore, the inspection angle intervals in the angle range where detailed detection is required can be made dense, and the intervals of other inspection angles can be made sparse. Thereby, the detection accuracy of the target is high and the detection time of the target can be shortened.

  In the above-described configuration, the position information is the direction of the calculation object, and the calculation means corresponds to a detection angle interval corresponding to the direction of the calculation object corresponding to a direction where the calculation object does not exist. It can be set as the structure dense with respect to the space | interval of a detection angle.

  In the above configuration, when the calculation means determines that the distance between the object and the plurality of antennas is equal to or greater than a predetermined distance and the object is moving away from the plurality of antennas, the calculation unit calculates the object. It can be set as the structure excluded from the target object. According to this configuration, it is possible to reduce the detection time while suppressing a decrease in detection accuracy of the object.

  In the above configuration, when the detection unit detects a plurality of objects, the calculation unit is configured to determine the distance between each of the plurality of objects and the plurality of antennas, and each of the plurality of objects and the plurality of antennas. Based on the relative speed, the calculation object can be selected. According to this configuration, since the number of calculation objects can be reduced by selecting a calculation object from a plurality of objects, the detection time can be reduced.

  In the above-described configuration, the object that is determined to be closest to the plurality of antennas when the detection means next detects the object among the plurality of objects is selected as the calculation object. Can do.

  In the above-described configuration, the calculation unit may calculate a part of detection angle intervals among a plurality of detection angles at which the detection unit next detects the target based on position information of the target acquired from another radar device. It can be set as the structure changed so that it may differ from the space | interval of another detection angle. According to this configuration, it is possible to effectively utilize the position information of the object captured by another radar device.

  The present invention uses a beat signal obtained for each of a plurality of antennas that receive a radar wave, detects a target at a plurality of detection angles, and calculates a calculation target from the target detected by the detection unit. Based on the position information of the object to be calculated, the detection means next detects the interval of some of the plurality of detection angles at which the object is detected so that the intervals of the other detection angles are different A radar control apparatus comprising: a calculating means for changing.

The present invention uses a beat signal obtained for each of a plurality of antennas that receive radar waves to detect an object at a plurality of detection angles, and selects a calculation object from the objects detected by the detection means. Based on the position information of the object to be calculated and the detection means so that the interval of some detection angles among the plurality of detection angles at which the detection unit next detects the object is different from the interval of other detection angles. And a step of changing to a radar apparatus control method.

  According to the present invention, the interval between the detection angles can be varied depending on the position information of the calculation object. Therefore, the inspection angle intervals in the angle range where detailed detection is required can be made dense, and the intervals of other inspection angles can be made sparse. Thereby, the detection accuracy of the target is high and the detection time of the target can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of a radar apparatus according to the first embodiment. Referring to FIG. 1, the radar apparatus includes a plurality of antennas 22, a switch 24, an RF (high frequency) unit 26, an ADC (AD conversion circuit) 28, and a microcomputer 10 (radar control apparatus). Other ECU (Electric Control Unit) 30, an acceleration sensor 32, a speed sensor 34, and a navigation system 36 are connected to the microcomputer 10 via an in-vehicle LAN. The plurality of antennas 22 receive millimeter waves that are radar waves. The number of antennas 22 is preferably from several to around 10, and is appropriately designed according to the purpose. The switch 24 selects the antenna 22 that receives the radar wave from the plurality of antennas 22. The RF unit 26 converts the radar wave received by the antenna 22 into a beat signal. The ADC 28 converts the beat signal from analog to digital.

  The microcomputer 10 has a CPU 11 and a memory 20. The CPU 11 includes an FFT unit 12, a detection unit 14, a calculation unit 16, and a control unit 18. The memory 20 is composed of, for example, a RAM, and stores a digital beat signal output from the ADC 28, a calculation result of the CPU 11, and the like. The FFT means 12 performs a fast Fourier transform on the digital beat signal stored in the memory 20 and stores the result in the memory 20. The detection means 14 performs digital beam forming processing based on the result of FFT calculated for each antenna 22, detects the position of the object, and outputs position information related to the position of the object. The calculation means 16 calculates a detection angle based on the position information of the object output by the detection means 14 and outputs the detection angle to the detection means 14. When the next digital beam forming process is performed, the detection unit 14 performs a process based on the detection angle calculated by the calculation unit 16. The control unit 18 controls the FFT unit 12, the detection unit 14, the calculation unit 16, the switch 24, the RF unit 26, and the ADC 28.

  The principle that the RF unit 26 outputs a beat signal will be described. FIG. 2A is a schematic diagram of the RF unit 26, and FIG. 2B is a diagram illustrating the frequencies of the transmission wave, the reception wave, and the beat signal with respect to time. Referring to FIG. 2A, the millimeter wave generated by the oscillator 38 is transmitted as a transmission wave from the antenna 21 (the antenna 21 is not shown in FIG. 1). As shown in FIG. 2B, the frequency of the transmission wave is transmitted as a triangular wave that linearly repeats the magnitude with time. Referring to FIG. 2A, the antenna 22 (antenna selected by the switch 24 in FIG. 1) receives a millimeter wave reflected by the object among the transmitted waves as a received wave. As shown in FIG. 2B, the time difference Δt between the received wave and the transmitted wave corresponds to the distance from the object, and the frequency difference Δf at each peak position between the received wave and the transmitted wave corresponds to the relative velocity with respect to the object. .

  Referring to FIG. 2A, a part of the transmission wave and the reception wave are mixed by the mixer 39 and output to the ADC 28 as a beat signal. The frequency of the beat signal is flat at the frequencies f1 and f2. The frequency f1 indicates a range in which the frequencies of the transmission wave and the reception wave increase, and the frequency f2 indicates a frequency difference between the transmission wave and the reception wave in a range in which the frequency of the transmission wave and the reception wave decreases. From the frequencies f1 and f2, the distance to the object and the relative speed can be detected. As described above, by using the FM-CW method, the distance to the object and the relative speed can be detected. In FIG. 2A, an amplifier or the like is not shown. Thereafter, the ADC 28 converts the analog beat signal output from the RF unit 26 into a digital signal and stores the digital signal in the memory 20.

  FIG. 3 is a diagram showing control performed by the CPU 11 in the microcomputer 10. The calculating means 16 sets the detection angle interval used for the DBF processing as an initial value (step S10). FIG. 4 is a diagram illustrating a detection angle with respect to the vehicle 100. Referring to FIG. 4, the direction of the angle θ with respect to the front direction 80 of the vehicle provided from the radar device 90 on the front surface of the vehicle 100 is the detection angle. The calculation means 16 sets θ as an initial value of the detection angle, for example, at an interval of 5 ° from −45 ° to 45 °. The FFT means 12 acquires a beat signal stored in the memory 20 and subjected to AD conversion (step S12). The FFT means 12 performs fast Fourier transform (FFT processing) on the AD-converted beat signal (step S14). Thereby, the spectrum characteristic equivalent to the power with respect to a discrete frequency can be obtained. FIG. 2C shows the spectral characteristics of the beat signal. In the spectral characteristics, the power at the frequencies f1 and f2 in FIG. The spectral characteristics are stored in the memory 20.

  The control means 18 determines whether it is the last antenna 22. In No, it returns to step S12. In this way, the beat signal for each of the plurality of antennas 22 is subjected to FFT processing. If Yes in step S16, that is, if the FFT processing has been performed for the beat signals of all the plurality of antennas 22, the process proceeds to step S18. The detection means 14 acquires the spectrum characteristics of each beat signal corresponding to the plurality of antennas 22 from the memory 20 (step S18). The detection means 14 performs DBF processing based on the detection angle, and detects the object and its position at a plurality of detection angles (step S20). As shown in FIG. 5A, the detection unit 14 performs DBF processing using the spectrum characteristics P1 to Pn of the beat signal corresponding to each antenna 22 and the detection angles of −45 ° to + 45 °. The detection unit 14 detects the direction in which the object is present among the detection angles from the result of the DBF process. Further, the distance and relative speed from the object are detected from the spectral characteristics of the beat signal corresponding to each antenna 22. Referring to FIG. 6, when the vehicle that is the object 102 is traveling in front of the vehicle 100 on which the radar device is mounted, the detection means 14 is directed to the forward direction 80 of the direction of the object 102 (for example, another vehicle). The angle θ, the distance A, and the relative speed V are output to the calculation unit 16 as position information that is information regarding the position of the object 102.

  With reference to FIG. 3, the calculation means 16 selects the calculation target object from a target object (step S22). Here, the target object 102 is the target object 102 detected by the detection means 14, and the calculation target object is an object used by the calculation means 16 for calculating the detection angle. In the first embodiment, the calculation means 16 selects the object 102 as the calculation object. The calculating means 16 determines the presence / absence of a calculation object (step S24). When the detection unit 14 cannot detect the object or when the calculation unit 16 does not select the calculation target, the calculation unit 16 determines that there is no calculation target and proceeds to step S28. If there is a calculation object in step S24, the calculation means 16 changes the detection angle interval corresponding to the detection angle based on the position information of the calculation object (step S26). That is, referring to FIG. 5B and FIG. 6, when the angle of the calculation object 102 is 10 °, the detection angles of the calculation object 102 and the vicinity range 86 in the beam range 84 of the radar wave are calculated. The intervals are 1 °, and the other detection angles are 10 °.

  The detection means 14 outputs the position information of the target object 102 to other ECUs 30 and the like (step S28). The control means 18 determines whether the process is finished (step S30). If yes, end. In No, it returns to step S12. Next DBF processing is performed. In step S20, as shown in FIG. 5B, the detection means 14 performs DBF processing using detection angles with a close detection angle interval near the object 102.

  According to the first embodiment, as in step S <b> 22 of FIG. 3, the calculation unit 16 sets the target detected by the detection unit 14 as a calculation target. As shown in step S26 of FIG. 3, FIG. 5B, and FIG. 6, based on the positional information regarding the position of the object to be calculated, the detection means 14 corresponds to the detection angle interval that is next used for the DBF processing. To change. For example, in FIG. 5B, the interval of some detection angles (8 ° to 12 °) among a plurality of detection angles (−45 ° to 45 °) at which the detection means 14 next detects the object. (1 °) is changed so as to be different from the interval (10 °) of other detection angles (angles other than 8 ° to 12 °) among the plurality of detection angles at which the detection unit 14 detects the object next. As described above, the interval between the detection angles can be changed according to the detection angle depending on the position of the object 102. Therefore, the intervals of the detection angles in the detection angle range where detailed detection is required can be made narrow, and the intervals of the other detection angles can be made sparse. Thereby, the detection accuracy of the object is high and the calculation time of the DBF processing can be shortened. When the DBF processing is reduced, it is possible to use the CPU 11 having a low processing speed and low cost. Therefore, an inexpensive radar apparatus can be provided.

  Further, as shown in FIGS. 5B and 6, the calculation means 16 can set the direction of the calculation object (for example, the angle θ in FIG. 6) as the position information. As a result, the calculation target object has a detection angle interval (for example, 1 °) corresponding to a direction (for example, θ = 10 °, range 86) from the vehicle 100 on which the radar device of the calculation target object 102 is mounted. It is possible to make it dense with respect to the interval (for example, 10 °) of the detection angle corresponding to the azimuth that is not. As shown in FIG. 6, there is a high possibility that the object 102 exists in the direction in which the object 102 exists even at the next scan. Therefore, by narrowing the interval between the detection angles of the direction of the object 102, the radar apparatus can focus on the periphery of the object 102. In addition, by making the detection angle intervals other than the direction in which the object 102 is present sparse, the detection accuracy is reduced with respect to the range 86, but the vehicle suddenly cuts in the direction other than the object 102, etc. However, a new object can be detected. In addition, the time required for DBF processing can be shortened.

  The second embodiment is an example in which the calculation unit 16 calculates the detection angle interval according to the lane in which the vehicle on which the radar apparatus is mounted travels. FIG. 7 is a flowchart illustrating the control performed by the CPU 11 of the radar apparatus according to the second embodiment, and corresponds to step S26 in FIG. In step S24 of FIG. 3, when the calculation means 16 determines that there is a calculation object, the calculation means 16 acquires longitude / latitude information (position information of the vehicle 100) of the vehicle 100 from the navigation system 36 (step S32). . Based on the latitude / longitude information and the position information of the calculation object, the calculation means 16 varies the detection angle interval at which the detection means 14 next detects the object within the beam range 84 (step S34). For example, referring to FIG. 8, when a vehicle 100 equipped with a radar apparatus is traveling on a road lane of a road 98, the detection angle interval of a range 86 in the vicinity of the object 102 in the radar wave beam range 84 is set to be small. In addition, the detection angle interval of the range 87 on the overtaking lane side in the beam range 84 of the radar wave is also made close.

  As described above, the detection angle interval is changed according to the lane in which the vehicle 100 travels. For example, when the lane in which the vehicle 100 travels is on the left side, the detection angle interval on the right side of the beam range 84 is made dense with respect to other ranges in the beam range 84. When the lane in which the vehicle 100 travels is on the left side, the right side of the beam range 84, and when the lane in which the vehicle 100 travels is in the center, the interval between the left and right detection angles in the beam range 84 is set to the beam range 84. Dense against other areas within. Thereby, even when another vehicle has interrupted from the adjacent lane, the other vehicle can be quickly detected as an object.

  The third embodiment is an example in which the calculation unit 16 calculates the detection angle interval based on the position information of the past object. FIG. 9 is a flowchart illustrating the control performed by the CPU 11 of the radar apparatus according to the third embodiment, and corresponds to step S26 in FIG. The calculating means 16 acquires the position information of the past calculation object from the memory 20 (step S36). Based on the past position information of the calculation object and the position information of the calculation object, the calculation means 16 varies the detection angle interval at which the detection means 14 next detects the object within the beam range 84 ( Step S34). For example, referring to FIG. 10, when the position of the object 102 detected by the detection means 14 is the previous time 103d, the position 103e of the object 102 at the next scan is predicted from the position of the object 102 and the position 103d. To do. The detection angle interval in the vicinity of the position 103 e in the beam range 84 is made dense with respect to other ranges in the beam range 84. Thus, the calculation means 16 predicts the position 103e where the next target object 102 exists based on the past position information of the calculation target object and the position information of the calculation target object, and the detection means 14 next sets the target object. The detection angle intervals for detecting objects can be varied within the beam range 84. Thereby, the range which makes the space | interval of a detection angle dense can be set more appropriately. It should be noted that the position 103e where the object 102 is next may be predicted from the distance and relative speed from the object 102 detected from the beat signal.

  The fourth embodiment is an example in which the calculation unit 16 does not set the target detected by the detection unit 14 in step S22 of FIG. 3 as the calculation target. FIG. 11 is an example of the control performed by the calculation means 16 in step S22 of FIG. FIG. 12 is a diagram showing the object 102. The calculating means 16 determines whether the target object 102 is moving away from the position information of the target object 102 (step S42). In FIG. 12, the object 102 is moving away from the vehicle 100. In the case of Yes, the calculation means 16 judges whether the distance with the target object 102 is more than the predetermined distance 88 from the positional information on the target object 102 (step S44). In FIG. 12, the distance between the object 102 and the vehicle 100 is a predetermined distance 88 or more. In the case of Yes, the calculating means 16 does not make the target object 102 the target for calculation (step S48). In the case of No in step S42 or step S44, the calculating means 16 sets the object 102 as the object for calculation (step S46).

  As described above, the calculation means 16 can determine the calculation target object from the target object 102 according to the distance and relative speed with respect to the target object 102. In particular, when the distance between the object 102 and the vehicle 100 equipped with the radar device (that is, the distance between the object 102 and the antenna 22) is equal to or greater than a predetermined distance and the object is moving away from the vehicle 100, the object The possibility that 102 affects the vehicle 100 is small. Therefore, the object 102 can be excluded from the calculation object. Thereby, calculation time can be reduced, suppressing the fall of the detection sensitivity of a target object.

  Further, the calculation means 16 can acquire the speed of the vehicle 100 from the speed sensor 34 and can change the predetermined distance 88 as appropriate according to the speed of the vehicle 100. For example, the predetermined distance 88 can be increased when the speed of the vehicle 100 is high, and the predetermined distance 88 can be decreased when the speed of the vehicle 100 is low.

  Example 5 is an example in the case where there are a plurality of objects. In step S20 of FIG. 3, when the detecting means 14 detects the objects 102a to 102c as shown in FIG. 13, the calculating means 16 uses the distance and relative speed from each of the objects 102a to 102c, and uses the highest priority. The object 102a having a high value can be selected as the object for calculation (step S22 in FIG. 3). In step S <b> 26 of FIG. 3, the calculation means 16 makes the detection angle interval of the range 86 a near the object 102 a in the beam range 84 closer to the other ranges in the beam range 84.

  As described above, when the detection unit 14 detects the plurality of objects 102a to 102c, the calculation unit 16 determines the distance between each of the plurality of objects 102a to 102c and the vehicle 100 (that is, each of the plurality of objects 102a to 102c). And the antenna 22) and the relative speed between each of the plurality of objects 102 a to 102 c and the vehicle 100 can determine the calculation object. As described above, by selecting the calculation object from among the plurality of objects 102a to 102c, the number of calculation objects can be reduced, so that the calculation speed of the DBF process can be increased.

  Further, the calculating means 16 calculates the object 102a determined to be closest to the vehicle 100 on which the antenna 22 is mounted when the detecting means 14 next detects the object among the plurality of objects 102a to 102c. You can choose as a thing. Thereby, it is possible to preferentially monitor the object 102a to be noted.

  Example 6 is another example when there are a plurality of objects. In step S20 of FIG. 3, for example, as shown in FIG. 14, when the detecting means 14 detects the objects 102a to 102c, the calculating means 16 determines the distance from each of the objects 102a to 102c in the step S22 of FIG. Using the speed, a plurality of calculation objects are selected from the plurality of objects 102a to 102c. In step S26 of FIG. 3, the detection angle interval is calculated based on the position information of each of the plurality of calculation objects 102a to 102c.

  For example, in FIG. 14, the objects 102 a and 102 b are approaching the vehicle 100 and the object 102 c is moving away from the vehicle 100. Therefore, the calculation means 16 predicts the distance between each of the plurality of calculation objects 102a to 102c and the vehicle 100 when the detection means 14 next detects the object. As a result, when the detection unit 14 detects the next object, it can be predicted that the object 102a is at the position 103a, the object 102b is at the position 103b, and the object 102c is at the position 103c. Based on the distance between the positions 103a to 103c and the vehicle 100, the object 102a is given priority 1, the object 102b is given priority 2, and the object 102c is given priority 3. The interval of the detection angles in the range 86a in the vicinity of the object 102a having the priority 1 is made the most dense. Next, the interval of the detection angles in the range 86b in the vicinity of the object 102b having the priority 2 is set to the next highest. Next, the intervals of the detection angles in the range 86c in the vicinity of the object 102c with the priority 3 are made denser next. In FIG. 14, the calculation means 16 may exclude some of the plurality of objects detected by the detection means 14 from the calculation objects.

  As described above, based on the position information regarding the positions of the plurality of calculation objects, the detection angle interval at which the detection unit 14 detects the next object can be varied within the beam range 84. As in the fifth embodiment, one calculation object is selected from a plurality of objects detected by the detection means 14, whereas in the sixth embodiment, the detection angle interval is more precisely associated with the detection angle. And can be changed. Further, as shown in FIG. 14, the calculation means 16 uses the detection means 14 as the next target based on the distances between the plurality of calculation objects 102 a to 102 c and the vehicle 100 when the detection means 14 performs the next DBF processing. The detection angle intervals for detecting objects can be varied within the beam range 84.

  The seventh embodiment is an example in which the intervals of the detection angles are not sparse at a certain value or more. Referring to FIG. 15, in the case where the detection angle interval θ1 in the vicinity of the object 102 is made denser than the detection angle interval θ2 in other ranges, the object 104 falls within the detection angle interval if θ2 is too large. As a result, the object 104 cannot be detected. Therefore, the calculation means 16 sets the minimum value of the detection angle interval when the detection means 14 next detects the object to be a predetermined value or more. Thereby, it can suppress that the space | interval of a detection angle becomes too sparse.

  Further, the calculation means 16 can acquire the speed of the vehicle 100 from the speed sensor 34 and can determine a predetermined value based on the speed of the vehicle 100. For example, when the speed of the vehicle 100 is high, it is required to detect a distant object. Therefore, the predetermined value can be reduced, and when the speed of the vehicle 100 is low, the predetermined value can be increased.

  The eighth embodiment is an example in which the calculation means 16 calculates the detection angle interval based on the acceleration information of the vehicle on which the plurality of antennas 22 are mounted. FIG. 16 is a flowchart illustrating the control performed by the CPU 11 of the radar apparatus according to the eighth embodiment, and corresponds to step S26 in FIG. The calculating means 16 acquires acceleration information related to the acceleration of the vehicle 100 from the acceleration sensor 32 (step S38). Based on the acceleration information and the position information of the calculation target, the calculation unit 16 varies the detection angle interval at which the detection unit 14 next detects the target within the beam range 84 (step S34).

  For example, referring to FIG. 17A, the vehicle 100 uses the target object 102d as the calculation target object out of the two target objects 102d and 100e, and sets the detection angle interval near the target object 102d within the beam range 84. Close to other ranges. When the vehicle 100 changes the course as indicated by the arrow for changing the lane, the calculation means 16 detects the course change from the acceleration information of the vehicle 100. The vehicle 100 comes closer to the object 102e than the object 102d by the course change. Therefore, the calculation means 16 sets the object 102e as the calculation object, and closes the detection angle interval in the vicinity of the object 102e with respect to other ranges in the beam range 84.

  As described above, the calculation means 16 can vary the detection angle interval at which the detection means 14 next detects the object within the beam range 84 based on the acceleration information and the position information of the calculation object. Thereby, when the vehicle 100 changes the course greatly, such as a lane change, an object approaching the vehicle 100 can be monitored.

  Note that the calculation unit 16 can vary the detection angle interval at which the detection unit 14 next detects the object within the beam range 84 based on the acceleration information of the vehicle 100. If the course is changed significantly, the position information of the object so far may not be available. In such a case, it is preferable to initialize the detection angle interval.

  Example 9 is an example in which position information of an object is acquired from another radar device. FIG. 18 is a flowchart illustrating the control performed by the CPU 11 of the radar apparatus according to the ninth embodiment, and corresponds to step S26 in FIG. Referring to FIG. 19A, in addition to a radar device 90 having a beam range 84, the vehicle 100 is equipped with radar devices 92 and 94 having a beam range 96 and detecting a lateral direction. The object 102 moves within the beam range 96 of the radar device 92 and is about to enter the beam range 84 of the radar device 90. The calculating means 16 acquires the position information of the target object 102 from the other radar apparatus 92 (step S40). Based on the position information of the object 102 acquired from the other radar apparatus 92, the calculating means 16 varies the detection angle interval at which the detecting means 14 next detects the object within the beam range 84 (step S34). With reference to FIG. 19B, the interval of the detection angle range of the range 86 that supplements the object 102 is made denser than the other ranges.

  According to the ninth embodiment, the calculation unit 16 detects the next detection of the target by the detection unit 14 based on the position information of the object 102 and the position information of the calculation target acquired from another radar device 92. The angular spacing can be varied within the beam range 84. Thereby, the position information of the target object captured by another radar device 92 can be effectively used. Further, in the radar device 90, the position information of the object detected by the detection means 14 may be output to the other radar devices 92 and 94.

  In the first to ninth embodiments, the case where the detecting unit 14 detects the object at the detection angle by performing the DBF process has been described as an example. The detection means 14 may detect the object at the detection angle by a mechanical scanning method.

  In addition, the range 86 in the vicinity of the calculation target object with different detection angles can be set as the range of the target object 102 or the position 103e. Moreover, it can also be set as the range further extended from the range of the target object 102 or the position 103e (for example, the range extended ± 10 °).

  Although the embodiments of the present invention have been described in detail, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

FIG. 1 is a block diagram of a radar apparatus according to the first embodiment. 2A is a circuit diagram of the RF unit, FIG. 2B is a diagram showing the principle of the FM-CW system, and FIG. 2C is a diagram showing the spectral characteristics of the beat signal subjected to FFT processing. FIG. 3 is a flowchart of control performed by the CPU of the first embodiment. FIG. 4 is a diagram showing detection angles. FIG. 5A and FIG. 5B are diagrams illustrating detection angles at which DBF processing is performed. FIG. 6 is a diagram illustrating a positional relationship between the vehicle 100 and the object 102 in the first embodiment. FIG. 7 is a flowchart illustrating a part of the control performed by the CPU of the second embodiment. FIG. 8 is a diagram illustrating a positional relationship between the vehicle 100 and the object 102 in the second embodiment. FIG. 9 is a flowchart illustrating a part of the control performed by the CPU of the third embodiment. FIG. 10 is a diagram illustrating a positional relationship between the vehicle 100 and the object 102 in the third embodiment. FIG. 11 is a flowchart illustrating a part of the control performed by the CPU of the fourth embodiment. FIG. 12 is a diagram illustrating a positional relationship between the vehicle 100 and the object 102 in the fourth embodiment. FIG. 13 is a diagram illustrating a positional relationship between the vehicle 100 and the objects 102a to 102c in the fifth embodiment. FIG. 14 is a diagram illustrating a positional relationship between the vehicle 100 and the objects 102a to 102c in the sixth embodiment. FIG. 15 is a diagram illustrating a positional relationship between the vehicle 100 and the object in the seventh embodiment. FIG. 16 is a flowchart illustrating a part of the control performed by the CPU of the eighth embodiment. FIGS. 17A and 17B are views showing the positional relationship between the vehicle 100 and the object 102 in the eighth embodiment. FIG. 18 is a flowchart illustrating a part of the control performed by the CPU of the ninth embodiment. FIG. 19A and FIG. 19B are diagrams showing the positional relationship between the vehicle 100 and the object 102 in the ninth embodiment.

Explanation of symbols

10 CPU
12 FFT means 14 Detection means 16 Calculation means 18 Control means 20 Memory 22 Antenna 24 Switch 80 Front direction 90 Radar device 100 Vehicle 102 Object

Claims (8)

A plurality of antennas for receiving radar waves;
Detecting means for detecting an object at a plurality of detection angles using beat signals obtained for each of the plurality of antennas;
Detection of a part of a plurality of detection angles at which the detection means selects a calculation object from the objects detected by the detection means, and the detection means next detects the object based on position information of the calculation object. A radar device, comprising: an arithmetic unit that changes an angle interval differently from other detection angle intervals. The position information is an orientation of the calculation object,
2. The calculation means, wherein a detection angle interval corresponding to an orientation of the calculation object is set closer to a detection angle interval corresponding to an orientation where the calculation object does not exist. The radar apparatus described.   When the calculation means determines that the distance between the object and the plurality of antennas is equal to or greater than a predetermined distance and the object is moving away from the plurality of antennas, the calculation object is removed from the calculation object. 3. The radar apparatus according to claim 1, wherein the radar apparatus is excluded. When the detection means detects a plurality of the objects,
The computing means selects the computing object based on the distance between each of the plurality of objects and the plurality of antennas and the relative speed between each of the plurality of objects and the plurality of antennas. The radar device according to any one of claims 1 to 3.   The calculation means selects, as the calculation object, an object determined to be closest to the plurality of antennas when the detection means next detects the object among the plurality of objects. The radar apparatus according to claim 4.   The calculation means determines the interval of some detection angles among the plurality of detection angles at which the detection means next detects the object based on the position information of the object acquired from another radar device. The radar apparatus according to claim 1, wherein the radar apparatus is changed so as to be different from the interval. Detecting means for detecting an object at a plurality of detection angles using beat signals obtained for each of a plurality of antennas for receiving radar waves;
Detection of a part of a plurality of detection angles at which the detection means selects a calculation object from the objects detected by the detection means, and the detection means next detects the object based on position information of the calculation object. A radar control apparatus, comprising: an arithmetic unit that changes an angle interval differently from other detection angle intervals. Detecting beats at a plurality of detection angles using beat signals obtained for a plurality of antennas that receive radar waves; and
Selecting a calculation object from the objects detected by the detection means;
Based on the position information of the calculation object, a step of changing a detection angle interval among a plurality of detection angles at which the detection unit next detects the object to be different from an interval of other detection angles. And a method of controlling the radar apparatus.

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