JP2019066240A - Radar device and information processing method - Google Patents

Abstract

To provide technology with which it is possible to accurately detect an angle deviation of a radar device.SOLUTION: A radar device is mounted in a vehicle having an automatic drive system that automatically controls steering. The radar device comprises a setting unit for setting a detection section in which target information for detecting an angle deviation of the own device is acquirable, and a calculation unit for acquiring the target information and calculating the magnitude of the angle deviation when the vehicle travels in the detection section during automatic drive.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radar device and an information processing method.

  The angle of the target calculated by the radar device is the relative angle between the antenna and the arrival direction of the radar wave. For this reason, when the attachment angle of the radar device deviates from the predetermined angle, the angle of the target may be calculated incorrectly. The angular deviation of the radar device occurs, for example, when the user or the like detaches the radar device, or when the vehicle body is deformed due to an accident or the like. The angular deviation of the radar device may occur due to aging. In consideration of such a point, conventionally, a technique has been devised to perform the axis adjustment of the target detection axis of the radar device (see, for example, Patent Document 1).

JP, 2011-43387, A

  The detection of the angular deviation of the radar device is performed when the vehicle satisfies a predetermined traveling condition. The predetermined traveling conditions include, for example, a condition that the vehicle travels in a straight line, and a condition that the radar device travels in a certain section or more while detecting a specific target.

  For example, even when the vehicle travels on a straight road, when the driver turns the steering wheel, the condition of straight travel is not satisfied. As a result, the accuracy of the calculation result of the magnitude of the deviation angle may decrease, or the time required to detect the angle deviation may increase as the work is redone. In addition, on a road where there are few specific targets, it is not possible to sufficiently detect angular deviation.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of accurately detecting an angular deviation of a radar device. Another object of the present invention is to provide a technique capable of quickly detecting an angular deviation of a radar device.

In order to achieve the above object, a radar device according to the present invention is a radar device mounted on a vehicle having an automatic driving system for automatically controlling steering, and acquires target information for detecting an angle deviation of the own device. A setting unit configured to set a possible detection zone; and a calculation unit configured to obtain the target information and calculate the magnitude of the angular deviation when the vehicle travels the detection zone during automatic driving It has a configuration (first configuration).
In the radar device of the first configuration, it is preferable that the setting unit is configured (second configuration) to set the detection section based on map information having three-dimensional static information.

  In the radar device of the second configuration, the setting unit sets the detection section on the basis of the information on the road shape and the stationary object acquired from the map information, and the calculator calculates the target information from the target information. Preferably, the size of the angular deviation is calculated based on the acquired trajectory of the stationary object (third configuration).

  In the radar device of the second configuration, the setting unit sets the detection section based on the information acquired from the map information and the information acquired from another vehicle having the automatic driving system, and Preferably, the calculation unit is configured (fourth configuration) to calculate the magnitude of the angular deviation based on the trajectory of the other vehicle acquired from the target information.

  In the radar device of the fourth configuration, the other vehicle is preferably an oncoming vehicle (fifth configuration).

  In the radar device having any one of the third to fifth configurations, the setting unit may be configured to detect the angular deviation according to the size of the stationary object or the other vehicle. It is preferable to be the structure (6th structure) which changes the minimum distance between the said stationary object or the said other vehicle, and sets the said detection area.

  In the radar apparatus of the sixth configuration, the setting unit shortens the minimum distance compared to the case where the width in the predetermined direction of the stationary object or the other vehicle is narrow (a seventh configuration Configuration) is preferable.

  In the radar device according to any one of the first to seventh configurations, it is preferable that the road shape of the detection section is a linear shape (eighth configuration).

  In order to achieve the above object, an information processing method according to the present invention is an information processing method in a radar apparatus mounted on a vehicle having an automatic driving system for automatically controlling steering, and detects an angular deviation of the radar apparatus. Setting step of setting a detection section from which target information can be acquired, and when the vehicle travels the detection section during automatic driving, the target information is acquired to calculate the magnitude of the angular deviation And a calculation step (9th configuration).

  According to the present invention, the angular deviation of the radar device can be detected accurately. Further, according to the present invention, the angular deviation of the radar device can be detected quickly.

The figure which shows the structure of the radar apparatus which concerns on 1st Embodiment. A flowchart showing the operation of the processing device provided in the radar device according to the first embodiment A diagram conceptually showing an angle estimated by azimuth calculation processing as an angle spectrum The figure for demonstrating the detection area set by the setting part of 1st Embodiment. Another diagram for explaining a detection section set by the setting unit of the first embodiment In the radar apparatus according to the first embodiment, a diagram for explaining a method of calculating the magnitude of the angular deviation The other figure for demonstrating the method to calculate the magnitude | size of angle shift in the radar installation concerning a 1st embodiment. A flowchart showing an example of an angular deviation detection procedure in the radar device according to the first embodiment The figure which shows the structure of the radar apparatus which concerns on 2nd Embodiment. The figure for demonstrating the detection area set by the setting part of 2nd Embodiment

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

<< 1. First embodiment >>
<1-1. Configuration of radar device>
FIG. 1 is a diagram showing the configuration of the radar device 1 according to the first embodiment. The radar device 1 is mounted, for example, on a vehicle such as a car. Hereinafter, a vehicle on which the radar device 1 is mounted may be referred to as a "vehicle". In addition, a direction in which the host vehicle travels straight ahead, which is directed from the driver's seat to steering, is referred to as "forward". In addition, a direction in which the host vehicle travels straight and is directed from the steering to the driver's seat is referred to as “rearward”. In addition, a direction perpendicular to the straight traveling direction of the vehicle and the vertical line, that is, a direction from the right to the left of the driver facing the front is referred to as “left direction”. Further, a direction perpendicular to the straight traveling direction of the vehicle and the vertical line, that is, a direction from the left to the right of the driver facing the front is referred to as “right direction”.

  The radar device 1 is mounted at the front end of the vehicle. In the present embodiment, the radar device 1 acquires target data relating to a target present ahead of the host vehicle using FMCW (Frequency Modulated Continuous Wave) which is a continuous wave frequency-modulated. Targets are classified into stationary targets and moving targets. The radar device 1 detects the horizontal orientation of the target. Here, the horizontal direction means a direction substantially horizontal to the road surface on which the vehicle equipped with the radar device 1 travels.

  The radar device 1 has a distance (hereinafter referred to as “longitudinal distance”) [m] until the reflected wave reflected from the target is received by the receiving antenna of the radar 1, and the relative velocity [km] of the target relative to the host vehicle / H] Target data having parameters such as the distance of the target in the lateral direction of the vehicle (hereinafter referred to as "lateral position") [m] is derived. The vertical position is, for example, a position at which the radar device 1 of the host vehicle is mounted as an origin O, and is represented by a positive value in front of the host vehicle and a negative value behind the host vehicle. The lateral position is represented by, for example, a position at which the radar device 1 of the host vehicle is mounted as an origin O, a positive value on the right side of the host vehicle, and a negative value on the left side of the host vehicle.

  As shown in FIG. 1, the radar device 1 mainly includes a transmitter 2, a receiver 3, and a processor 4.

  The transmitter 2 includes a signal generator 21 and a transmitter 22. The signal generation unit 21 generates a modulation signal in which the voltage changes in a triangular wave shape, and supplies the modulation signal to the transmitter 22. The transmitter 22 frequency-modulates the continuous wave signal based on the modulation signal generated by the signal generation unit 21, generates a transmission signal whose frequency changes as time passes, and outputs the transmission signal to the transmission antenna 23.

  The transmission antenna 23 outputs the transmission wave TW to the front of the host vehicle based on the transmission signal from the transmitter 22. The transmission wave TW output from the transmission antenna 23 is an FMCW whose frequency rises and falls in a predetermined cycle. The transmission wave TW transmitted to the front of the host vehicle from the transmission antenna 23 is reflected by an object such as a person, another vehicle, a roadside object, a road surface, or a lower object to form a reflected wave RW.

  The receiving unit 3 includes a plurality of receiving antennas 31 forming an array antenna, and a plurality of individual receiving units 32 connected to the plurality of receiving antennas 31. In the present embodiment, the receiving unit 3 includes, for example, four receiving antennas 31 and four individual receiving units 32. The four individual reception units 32 correspond to the four reception antennas 31 respectively. Each receiving antenna 31 receives the reflected wave RW from the object and obtains a received signal, and each individual receiving unit 32 processes the received signal obtained by the corresponding receiving antenna 31.

  Each individual reception unit 32 includes a mixer 33 and an A / D converter 34. The received signal obtained by the receiving antenna 31 is amplified by a low noise amplifier (not shown) and then sent to the mixer 33. The transmission signal from the transmitter 22 of the transmission unit 2 is input to the mixer 33, and the transmission signal and the reception signal are mixed in the mixer 33. As a result, a beat signal having a beat frequency that is the difference between the frequency of the transmission signal and the frequency of the reception signal is generated. The beat signal generated by the mixer 33 is converted to a digital signal by the A / D converter 34 and then output to the processing device 4.

  The processing device 4 includes a microcomputer including a CPU (Central Processing Unit), a memory 41, and the like. The processing device 4 stores various data to be operated on in the memory 41 which is a storage device. The memory 41 is, for example, a random access memory (RAM). The processing device 4 includes a transmission control unit 42, a Fourier transform unit 43, a signal processing unit 44, and an angular deviation detection unit 45 as functions realized as software by a microcomputer. The transmission control unit 42 controls the signal generation unit 21 of the transmission unit 2.

  The Fourier transform unit 43 performs fast Fourier transform (FFT) on beat signals output from each of the plurality of individual reception units 32. Thereby, the Fourier transform unit 43 transforms the beat signal related to the reception signal of each of the plurality of reception antennas 31 into a frequency spectrum which is data in the frequency domain. The frequency spectrum obtained by the Fourier transform unit 43 is input to the signal processing unit 44.

  The signal processing unit 44 executes target data acquisition processing, and acquires target data concerning a target in front of the host vehicle based on the frequency spectrum of each of the plurality of receiving antennas 31. The signal processing unit 44 outputs a control signal according to the processing result to the vehicle control ECU 61 or the like.

  As shown in FIG. 1, the signal processing unit 44 has a target data derivation unit 441, a target data processing unit 442, a determination unit 443 and a data transmission unit 444 as main functions.

  The target data derivation unit 441 derives target data relating to the target based on the frequency spectrum obtained by the Fourier transform unit 43. The target data processing unit 442 performs various processing such as filtering on the derived target data. The determination unit 443 determines whether the classified target is an unnecessary target. The data transmission unit 444 transmits a transmission signal according to the determination result of the determination unit 443 to the vehicle control ECU 61 or the like. Thus, the vehicle control ECU 61 or the like can appropriately execute, for example, processing necessary to prevent the host vehicle from colliding with an obstacle.

  The angular deviation detection unit 45 detects the deviation of the mounting angle of the radar device 1 from the reference mounting angle. The radar device 1 is attached to a predetermined position of a vehicle with a preset reference axis directed in a predetermined direction. The reference axis corresponds to, for example, the optical axis of the transmission wave. For example, the reference axis of the radar device 1 is oriented parallel to the front-rear direction. If the mounting angle of the radar device 1 deviates from the reference mounting angle, the target data acquired by the radar device 1 becomes inaccurate, and the system such as collision avoidance executed by the vehicle control ECU 61 may malfunction. is there. In the present embodiment, the angular deviation information detected by the angular deviation detection unit 45 is input to the target data processing unit 442 in order to avoid such a malfunction. The target data processing unit 442 appropriately corrects and processes the target data derived by the target data deriving unit 441 based on the angle deviation information.

<1-2. Processing device operation>
Next, the main operation of the processing device 4 will be described. FIG. 2 is a flowchart showing the operation of the processing device 4 provided in the radar device 1 according to the first embodiment. The processing device 4 periodically repeats the process shown in FIG. 2 every fixed time (for example, 1/20 second).

  Before the start of the process shown in FIG. 2, the control of the signal generation unit 21 by the transmission control unit 42 is completed. First, the Fourier transform unit 43 performs fast Fourier transform on beat signals output from each of the plurality of individual reception units 32 (step S1). Then, the frequency spectrums of both the up section (section in which the frequency of the transmission wave TW rises) and the down section (section in which the frequency of the transmission wave TW falls) of all four receiving antennas 31 are signals from the Fourier transform unit 43 It is input to the processing unit 44.

  Next, the target data derivation unit 441 extracts peak frequencies for the frequency spectrum (step S2). The target data deriving unit 441 extracts, as a peak frequency, a frequency at which a peak having a power exceeding a predetermined threshold appears in the frequency spectrum.

  Next, the target data derivation unit 441 estimates the angle of the target related to the extracted signal of the peak frequency by the azimuth calculation processing. In the azimuth calculation process, the power of the signals of the plurality of angles and the plurality of angles is derived from the signal of one peak frequency.

  FIG. 3 is a diagram conceptually showing the angle estimated by the azimuth calculation process as an angle spectrum. In the figure, the horizontal axis indicates the angle (deg), and the vertical axis indicates the power of the signal. In the angular spectrum, the angle estimated by the azimuth calculation process appears as a peak Pa. Hereinafter, the angle estimated by the azimuth calculation process is referred to as “peak angle”, and the power of the signal of the peak angle is referred to as “angular power”. Thus, the plurality of peak angles simultaneously derived from the signal of one peak frequency indicate the angles of a plurality of targets existing at the same vertical distance (longitudinal distance corresponding to the peak frequency).

  The target data derivation unit 441 derives the peak angle and the angle power of each of a plurality of targets existing at the same vertical distance (step S3).

  Thereby, the target data derivation unit 441 derives section data corresponding to each of the plurality of targets existing in front of the host vehicle. The target data derivation unit 441 derives interval data having parameters of peak frequency, peak angle, and angular power in both the up interval and the down interval.

  Next, the target data derivation unit 441 associates the section data of the up section with the section data of the down section by pairing processing (step S4). The target data derivation unit 441 associates, for example, two section data having similar parameters (peak frequency, peak angle, and signal power) using an operation using Mahalanobis distance.

  The target data derivation unit 441 further derives pair data based on the two interval data, when the two interval data of the up interval and the down interval can be associated with each other. The target data derivation unit 441 uses the parameters of the two section data of the up section and the down section that are the source of the pair data for each of the derived pair data, to obtain the parameters of the pair data (vertical distance, relative velocity And the horizontal position) are derived (step S5).

  Next, the target data derivation unit 441 determines target data relating to the target from among the derived pair data. The pair data derived by the target data deriving unit 441 includes unnecessary data such as noise. Therefore, the target data derivation unit 441 determines only the pair data related to the target among the derived pair data as the target data.

  The target data derivation unit 441 associates each of the derived pair data with the target data determined in the past, based on the parameters. The target data derivation unit 441 associates the pair data having similar parameters (longitudinal distance, relative velocity and lateral position) with the past target data. Then, the target data derivation unit 441 determines the pair data that can be associated with the past target data as target data relating to the target.

  The pair data that can not be associated with the past target data also includes target data relating to a newly appearing target. For this reason, the target data derivation unit 441 continuously performs predetermined times (for example, three times) or more in the target data acquisition process after the next time for pair data that can not be associated with the past target data. When it is possible to associate with the past pair data, it is decided as target data relating to a newly appeared target.

  By such processing, the target data deriving unit 441 derives target data relating to targets in the vicinity of the host vehicle. Since the target data acquisition process is periodically repeated every predetermined time (for example, 1/20 second), the target data derivation unit 441 can derive target data related to the target every predetermined time. Become.

  Each target data has parameters such as vertical distance, relative velocity, and horizontal position. At the same time, various processing variables used for processing are set to each target data. The processing variables include "stationary target flag" and the like. The target data processing unit 442 performs filtering to smooth the parameters of the target data (longitudinal distance, relative velocity and horizontal position) in the time axis direction (step S6). Target data after such filtering is also referred to as "filter data" for paired data representing instantaneous values.

  The target data processing unit 442 determines the ground speed of the target related to the target data based on the relative speed of the target data and the speed of the own vehicle obtained from the vehicle speed sensor (not shown) mounted on the Derivation of the absolute speed) and the traveling direction. Then, the target data processing unit 442 classifies the target based on the derived ground speed and the traveling direction. The classification of targets includes, for example, preceding vehicles, oncoming vehicles, stationary objects, and the like.

  Next, the determination unit 443 determines whether the classified target is a target necessary for control of a system including the vehicle control ECU 61 (step S7). The discrimination result is included in the target data.

  Next, based on the parameters (longitudinal distance, relative velocity, and horizontal position) of the target data, the target data processing unit 442 estimates a plurality of target data that can be estimated as target data related to the same object. Group together (step S8).

  Finally, the data transmission unit 444 generates a transmission signal according to the determination result included in the target data thus processed, and transmits the transmission signal to the vehicle control ECU 61 or the like. The data transmission unit 444 selects a predetermined number (for example, 10) of target data from the grouped target data as an output target (step S9), and generates a transmission signal using only the selected target data. Do. The data transmission unit 444 preferentially selects target data related to a target close to the host vehicle, in consideration of the vertical distance and the horizontal position of the target data.

  For example, the target data selected as the output target in the above processing is stored in the memory 41 and used as past target data in the target data acquisition process from the next time onward.

<1-3. Angle deviation detection>
Next, the angular deviation detection function realized by the angular deviation detection unit 45 will be described in detail.

  In the present embodiment, the vehicle on which the radar device 1 is mounted has an automatic driving system 60 that automatically controls steering. The autonomous driving system 60 includes a vehicle control ECU 61. The automatic driving system 60 may be configured to automatically control only the steering, but may be configured to automatically control at least one of the driving force and the braking force in addition to the steering. The angular deviation detection unit 45 recognizes whether or not the automatic driving is performed by the driving mode signal transmitted by the vehicle control ECU 61. The operation mode signal may be, for example, an on / off signal. When the on signal is input, the angular deviation detection unit 45 recognizes that the host vehicle is performing automatic driving. When the off signal is input, the angle deviation detection unit 45 recognizes that the host vehicle is not performing automatic driving. The angular deviation detection unit 45 performs angular deviation detection when the host vehicle is performing automatic driving.

  As shown in FIG. 1, the angular deviation detection unit 45 includes a setting unit 451 and a calculation unit 452 as main functions. In other words, the radar device 1 includes the setting unit 451 and the calculating unit 452.

  The setting unit 451 sets a detection section in which target information for detecting an angular deviation of the radar device 1 (own device) can be acquired. In the present embodiment, the setting unit 451 sets a detection section based on the map information 410 having three-dimensional static information. Map information 410 is high-precision three-dimensional map information. The map information 410 includes road shape information including inclination information. The map information 410 includes three-dimensional structure information. In the present embodiment, the map information 410 is stored in the memory 41. However, the map information 410 may be stored in a memory provided in a portion different from the radar device 1 of the host vehicle. Further, as another example, the map information 410 may be acquired by communication from an information center provided separately from the host vehicle. The target information is information acquired by the operation of the radar device 1 and includes, for example, a vertical distance, a relative velocity, and a horizontal position.

  The setting unit 451 sets a detection section based on the information on the road shape and the stationary object acquired from the map information 410. FIG. 4 is a diagram for explaining a detection section set by the setting unit 451 of the first embodiment. In FIG. 4, reference numeral 100 denotes a vehicle, reference numeral 101 denotes a road, and reference numeral 102 denotes a roadside object. The roadside object 102 is an example of a stationary object.

  As shown in FIG. 4, the road shape of the detection section is a linear shape. The setting unit 451 extracts a straight road from the map information 410 and sets it as a detection section candidate. More specifically, the setting unit 451 extracts a straight road from among the route information on which the vehicle is scheduled to pass by automatic driving. The route information is input from, for example, the vehicle control ECU 61 to the angular deviation detection unit 45. A straight road is, for example, a road that satisfies the condition that the absolute value of R (turning radius) is larger than 5000. However, this condition is an example and may be changed as appropriate. Moreover, it is preferable that a straight road is a flat road where the uphill and the downhill are not repeated.

  In this configuration, when the host vehicle 100 travels the straight road 101 by automatic driving, target information for detecting an angle deviation can be accumulated. For this reason, the possibility of the steering wheel of the vehicle 100 being shaken during storage of target information is low, and target information for detecting an angle deviation can be accurately and quickly acquired.

  When setting the detection section, the setting unit 451 sets the detection section in consideration of not only the shape of the road 101 but also the information of the stationary object acquired from the map information 410. The stationary object is preferably one having a high reflection intensity. The stationary object may be, for example, a guardrail, a pole having a reflector, a signboard or the like. The setting unit 451 sets a straight road with many stationary objects with high reflection intensity as a detection section. For example, as illustrated in FIG. 4, the setting unit 451 sets a place where a plurality of roadside objects 102 are arranged along the road 101 as a detection section. In the present embodiment, the roadside object 102 is a stationary object with high reflection intensity disposed at the end of the road 101.

  In the present embodiment, a straight road on which a plurality of roadside objects 102 are arranged at the left end of the road 101 is set as a detection section, but this is an example. The number of roadside objects 102 may be one in some cases. If there is one roadside object 102, the roadside object 102 may extend continuously along a straight road, such as a guardrail. Also, the roadside object 102 may exist only at the right end of the road 101 or at the left and right ends of the road 101.

  FIG. 5 is another diagram for describing a detection section set by the setting unit 451 of the first embodiment. Also in FIG. 5, reference numeral 100 is a host vehicle, reference numeral 101 is a road, reference numeral 102 is a roadside object, and is an example of a stationary object.

  The setting unit 451 sets the detection section by changing the minimum distance L between the vehicle 100 and the stationary object required for detecting the angular deviation according to the size of the stationary object (roadside object 102). Do. The size of the stationary object may be acquired from, for example, the map information 410. As another example, the size of the stationary object may be acquired from reflection point information of the stationary object acquired by the radar device 1. In addition, as another example, the size of the stationary object may be acquired based on information acquired from a sensor different from the radar device 1 such as a camera mounted on the host vehicle 100.

  Depending on the size of the stationary object, the size of the portion that reflects the transmission wave transmitted from the radar device 1 varies. The large stationary object in the reflection part has a larger variation in reflection point than the small stationary object in the reflection part, and the variation in angle information included in the target information tends to be large. For this reason, it is preferable to acquire target information at a position farther from the radar device 1 than a large stationary object in the reflective portion, as compared to a small stationary object in the reflective portion. Thereby, the dispersion | variation in the target information obtained from the large stationary object of a reflective part can be suppressed. In this respect, in the present configuration, since the minimum distance L is changed according to the size of the stationary object, it is possible to improve the accuracy of the target information accumulated for detecting the angular deviation.

  In detail, the setting unit 451 shortens the minimum distance L in the case where the width in the predetermined direction of the stationary object is narrow is larger than in the case where the width is small. In the example shown in FIG. 5, the width in the predetermined direction is the width in the left-right direction. The width in the left-right direction of the first roadside object 102a on the back side as viewed from the host vehicle 100 is a first width W1. The width in the left-right direction of the second roadside object 102b in front of the host vehicle 100 is the second width W2. When the width in the left-right direction is the first width W1, the setting unit 451 sets the minimum distance L necessary for detecting the angular deviation as the first distance L1, and the width in the left-right direction is greater than the first width W1. In the case of the narrow second width W2, the minimum distance L necessary for detection of the angular deviation is set to the second distance L2 shorter than the first distance L1.

  That is, the setting unit 451 detects the distance from the host vehicle 100 in the case of the first roadside object 102a having a wider width in the lateral direction than in the case of the second roadside object 102b having a narrower width in the lateral direction. Set the start position of the section. In other words, even if the setting unit 451 finds a straight road having the first roadside object 102a suitable for angular deviation detection near the host vehicle 100, the distance between the host vehicle 100 and the first roadside object 102a is If the distance d is shorter than the first distance L1, the straight road is not set as the detection section. On the other hand, when the setting unit 451 finds a straight road having the second roadside object 102b near the host vehicle 100 suitable for detecting an angle deviation, the distance between the host vehicle 100 and the second roadside object 102b is Even if it is shorter than the one distance L1, if it is longer than the second distance L2, the straight road is set as the detection section. According to this configuration, it is possible to secure target distance for detecting an angular deviation while securing a sufficient distance for a roadside object 102b having a large width where the variation of the reflection point becomes large. For this reason, the accuracy of the stored information can be improved.

The angle between the straight line connecting the transmission position of the transmission wave of the radar apparatus 1 and the left end of the roadside object 102 and the straight line connecting the above transmission position and the right end of the roadside object 102 in plan view from above In the case of θ, the minimum distance L is calculated, for example, by the following equation (a). In the calculation of the minimum distance L, it is preferable to set, for example, 2 ° or less to θ in the equation (a), and θ = 2 °. tan is calculated based on degree.
Minimum distance L (((roadside object width W) / 2) / tan (θ / 2) (a)
For example, when the width W1 of the first roadside object 102a is 1 m, the minimum distance L1 is preferably 29 m or more. For example, when the width W2 of the second roadside object 102b is 0.2 m, the minimum distance L2 is preferably 6 m or more.

  Further, the end point position of the detection section is not particularly limited, but, for example, the end point position of the straight road, the final position of the roadside object 102 seen from the traveling direction of the vehicle 100, the position slightly ahead of them. Etc. The detection section is a section in which information for detecting an angle shift can be acquired, and acquisition of information for detecting an angle shift may be performed in the entire range of the detection section, but in a partial range It may be done.

  When the vehicle travels in the detection section during automatic driving, the calculation unit 452 obtains target information for detecting the angular deviation of the radar device 1 and calculates the magnitude of the angular deviation of the radar device 1 . In this configuration, since the calculation unit 452 uses automatic operation and high-precision three-dimensional map information, it is possible to accurately and quickly acquire target information necessary to detect an angle deviation. The magnitude of the angular deviation can be calculated accurately and quickly.

  In the present embodiment, the calculation unit 452 can determine whether or not the automatic driving is being performed based on the information input from the vehicle control ECU 61. In addition, the calculation unit 452 can determine whether or not the host vehicle has traveled the detection section based on position information obtained from a GPS sensor (not shown) included in the host vehicle.

  The calculation unit 452 acquires target information including the distance, the relative velocity, and the angle from the target data derivation unit 441. The target information acquired by the calculation unit 452 may be filter data. The calculation unit 452 acquires target information that is periodically and repeatedly obtained in the detection section for a predetermined number of times. The target information of each time is stored in the memory 41. The detection section is set using the map information 410 at a position where a stationary object (target) having a high reflection intensity is present. For this reason, the target information obtained from the target data deriving unit 441 usually includes target information of a stationary object previously assumed for detecting an angular deviation.

  The target information obtained from the target data derivation unit 441 may include target information other than the stationary object previously estimated for detecting the angular deviation. Even in such a case, it is calculated because the target assumed in advance for detecting the angular deviation is a stationary object or has the peculiarity associated with being continuously or periodically placed on a straight road. The part 452 can specify target information of a stationary object previously assumed for angular deviation detection.

  The calculation unit 452 calculates the magnitude of the angular deviation of the radar device 1 based on the trajectory of the stationary object acquired from the target information. As described above, the calculation unit 452 can obtain the trajectory of the stationary object that moves relative to the traveling of the host vehicle 100 because the calculation unit 452 acquires target information a plurality of times. The stationary object referred to here is a stationary object previously assumed for angular deviation detection.

  The radar device 1 is configured to detect, for example, the horizontal orientation of a target. Next, the method of calculating the magnitude of the angular deviation in the horizontal plane will be described in detail.

  FIG. 6 is a diagram for explaining a method of calculating the magnitude of the angular deviation in the radar device 1 according to the first embodiment. FIG. 7 is another view for explaining the method of calculating the magnitude of the angular deviation in the radar device 1 according to the first embodiment. FIG. 6 is a diagram showing a state in which the radar device 1 does not deviate from the reference angle in the horizontal plane. FIG. 7 is a diagram showing a state in which the radar device 1 is angularly displaced from the reference angle in the horizontal plane. 6 and 7, the X axis is an axis parallel to the longitudinal direction, the Y direction is an axis parallel to the lateral direction, and the Z axis is an axis parallel to the height direction.

  The radar device 1 is mounted on the vehicle 100 such that the reference axis is parallel to the front-rear direction (X axis). For this reason, when the detection section is set as shown in FIG. 4 and the radar device 1 does not cause an angular shift in the horizontal plane, the roadside object 102 acquired from the target information as shown in FIG. The locus of H appears on the left side of the vehicle 100 and extends in parallel with the X axis.

  On the other hand, when the radar device 1 is angularly displaced in the horizontal plane, as shown in FIG. 7, the trajectory of the roadside object 102 obtained from the target object information is inclined with respect to the X axis. In the example shown in FIG. 7, the trajectory of the roadside object 102 is inclined from the right to the left, and the radar device 1 has an angular deviation inclining from the X-axis direction to the left. In the case where the radar device 1 is inclined in the right direction from the X-axis direction, the trajectory of the roadside object 102 is inclined from the left to the right.

  The locus of the roadside object 102 (hereinafter referred to as a reference locus) in the case where no angular deviation of the radar device 1 occurs in the horizontal plane extends linearly, and the direction in which the locus extends can be estimated. In the present embodiment, it can be estimated that the reference trajectory of the roadside object 102 extends in a direction parallel to the X axis. The calculation unit 452 compares the reference trajectory with the trajectory of the roadside object 102 acquired when the host vehicle 100 travels in the detection section by automatic driving (hereinafter, referred to as a measured trajectory) to thereby obtain a radar. The magnitude of the angular deviation in the horizontal plane of the device 1 can be calculated. The calculation unit 452 obtains a rotation angle around the Z axis of the XY coordinates, which is required to make the direction of the reference trajectory coincide with the direction of the measurement trajectory, and uses this rotation angle as a shift angle. In the case of the present embodiment, the deviation angle is obtained, for example, by determining the inclination of the measured trajectory with respect to the X axis in the vehicle horizontal direction.

  In the present embodiment, angular deviation is detected using target information acquired when the vehicle 100 automatically drives a straight road. For this reason, it is possible to avoid turning off the steering wheel during the detection of the angular deviation, and to detect the angular deviation accurately. In addition, since the steering wheel can be avoided from being turned off during the detection of the angular deviation, it is possible to reduce the probability that re-detection of the angular deviation will occur. In addition, since the location where the reflector is present is set in advance as the detection section according to the map information, it is possible to avoid the occurrence of a situation where the angle misalignment detection is repeated because there are few reflectors. It can be performed.

  In the example shown in FIG. 4, in the case where the radar device 1 causes an angular shift in the right direction, it is possible that the roadside object 102 can not be detected by the radar device 1 if the shift angle is large. For this reason, it is preferable to set the location where the roadside thing 102 exists in the left-right both sides of the road 101 as a detection area. In addition, when no roadside object 102 to be detected is detected at all, it is expected that a large angular deviation occurs. For this purpose, the driver may be notified of the abnormality of the radar device 1 or the stop processing of the automatic control system 60 using the radar device 1 may be performed.

  In addition, when the radar device 1 is configured to detect not only the horizontal direction but also the vertical direction, in order to detect the angular deviation of the radar device 1, the deviation in the rotational direction in the XYZ axes may be derived. The vertical direction means a direction substantially perpendicular to the road surface on which the vehicle equipped with the radar device 1 travels. Also in this case, the magnitude of the angular deviation can be calculated based on the comparison between the reference trajectory and the actual measurement trajectory. The magnitude of the angular deviation may be calculated using, for example, the rotation angle around the X axis α, the rotation angle around the Y axis β, and the rotation angle γ around the Z axis using the Euler angle. The magnitude of the angular deviation may be calculated, for example, using quaternions instead of the Euler angles. Further, instead of simultaneously calculating the deviation angles in the rotational direction of all the axes of XYZ, the deviation angle (γ) in the XY plane, the deviation angle (β) in the ZX plane, and the deviation angle (α in the YZ plane) May be calculated separately.

  In addition, it is possible that the radar device 1 can not detect the target in the X-axis direction or the Y-axis direction. In the former case, only the deviation angle (α) in the YZ plane may be calculated, and in the latter case, only the deviation angle (β) in the ZX plane may be calculated.

  Next, an information processing method performed by the radar device 1 for detecting an angular deviation will be described. FIG. 8 is a flowchart showing an example of an angular deviation detection procedure in the radar device 1 according to the first embodiment. The angular deviation detection operation is started when the drive source of the vehicle is activated. If the drive source is an internal combustion engine, the angular displacement detection operation is started by starting the engine. When the drive source is a hybrid system or an EV (Electric Car) system, when the system power is turned on, an angular deviation detection operation is started. The angular deviation may be started at a specific timing, for example, when an instruction is given from the outside.

  First, based on the map information 410 having three-dimensional dynamic information, the angular deviation detection unit 45 sets a detection section in which target information for detecting angular deviation of the radar device 1 can be acquired (step S11). ). Based on the map information 410, the angle deviation detection unit 45 sets a straight road with many reflective objects as a detection section. When setting the detection section, the angular deviation detection unit 45 may refer to route information set in a navigation device (not shown) or the like provided in the own vehicle.

  After setting the detection section, the angular deviation detection unit 45 monitors whether or not the own vehicle has started traveling of the detection section by automatic driving (step S12). This monitoring is maintained until the host vehicle starts traveling of the detection section by automatic driving. In the present embodiment, the angular deviation detection unit 45 can recognize whether or not the own vehicle is performing the automatic driving based on the driving mode signal input by the vehicle control ECU 61. Moreover, it can be confirmed by the information obtained from the GPS sensor not shown, for example with which the own vehicle is equipped whether the driving | running | working of the detection area was started.

  In addition, when the host vehicle does not perform the automatic driving before reaching the detection section, the driver may be recommended to switch to the automatic driving to adjust the radar device 1. For example, voice or message display using a screen may be used as the recommendation means. In the case of this configuration, the driver may be notified of the end of travel in the detection section using voice or screen display. In addition, when the host vehicle does not perform the automatic driving before reaching the detection section, the automatic driving may be automatically switched to adjust the radar device 1. In this case, it is preferable to notify the driver of switching to the automatic driving to the driver by voice or screen display. Preferably, automatic switching to automatic driving is performed after the notification is performed. Also in the case of this configuration, it may be configured to notify the driver of the end of travel of the detection section using voice and screen display. In addition, at the end of traveling in the detection section, the automatic driving may be ended after confirming with the driver whether or not the automatic driving may be ended.

  When detecting the start of traveling of the detection section by automatic driving, the angular deviation detection unit 45 starts acquisition of target information (step S13). In the present embodiment, the angular deviation detection unit 45 acquires target information including the distance, the relative speed, and the angle from the target data derivation unit 441.

  When acquiring the target information, the angular deviation detection unit 45 checks whether a predetermined number of target information has been acquired (step S14). The predetermined number is a number stored in advance in the memory 41 as the number required to detect the angle deviation. If the target information has not reached the predetermined number (No in step S14), the angular deviation detection unit 45 is newly acquired next to the target information previously acquired by the target data derivation unit 441. The target information is acquired from the target data derivation unit 441 (step S15). The angular deviation detection unit 45 repeats this procedure until the target information reaches a predetermined number.

  After acquiring a predetermined number of target information, the angular deviation detection unit 45 calculates the deviation angle of the radar device 1 (step S16). The calculation of the displacement angle is calculated by comparing the above-described reference trajectory of the stationary object previously assumed to be used for angular displacement detection with the actually-measured trajectory. In the present embodiment, the calculated angle deviation information is input to the target data processing unit 442. The target data processing unit 442 appropriately corrects and processes the target data derived by the target data deriving unit 441 based on the angle deviation information.

<< 2. Second embodiment >>
Next, a second embodiment will be described. In the description of the second embodiment, components that overlap with the first embodiment will be described using the same reference numerals. Moreover, about the content which overlaps with 1st Embodiment, the description is abbreviate | omitted, when there is no need of description in particular.

<2-1. Configuration of radar device>
FIG. 9 is a view showing the configuration of the radar device 5 according to the second embodiment. The configuration of the radar device 5 of the second embodiment is almost the same as the configuration of the first embodiment. The second embodiment differs in that information acquired by the communication unit 70 of the host vehicle is input to the angle deviation detection unit 45A. The communication unit 70 is a communication unit that acquires information of another vehicle. That is, other vehicle information is input to the angle deviation detection unit 45A. Specifically, the communication unit 70 may be a communication unit that performs inter-vehicle communication, or may be a communication unit that performs inter-vehicle communication. The communication unit 70 may be mounted on the radar device 5.

2-2. Processing device operation>
The radar device 5 of the second embodiment also includes the processing device 4. The basic operation of the processing device 4 is the same as that of the first embodiment, and thus the description thereof is omitted. The processing apparatus 4 of the second embodiment also has the angular deviation detection unit 45A, but there are parts different from the first embodiment in the operation of the angular deviation detection unit 45A. Hereinafter, this different part will be described.

<2-3. Angle deviation detection>
In the second embodiment, angular deviation detection is performed when the host vehicle is performing automatic driving. This point is the same as that of the first embodiment. In the first embodiment, the angular deviation is detected using a stationary object (for example, the roadside object 102). In the second embodiment, angular displacement is detected using another vehicle which is a moving object. This point is different from the first embodiment. As shown in FIG. 9, the angular deviation detection unit 45A includes a setting unit 451A and a calculation unit 452A as main functions.

  The setting unit 451A sets the detection section based on the information acquired from the map information 410 and the information acquired from the other vehicle having the automatic driving system. FIG. 10 is a diagram for describing a detection section set by the setting unit 451A of the second embodiment. In FIG. 10, reference numeral 100 denotes a host vehicle, reference numeral 101 denotes a road, and reference numeral 200 denotes another vehicle. In the example shown in FIG. 10, the other vehicle 200 is an oncoming vehicle.

  As shown in FIG. 10, the road shape of the detection section is linear. As in the first embodiment, the setting unit 451A extracts a straight road from the map information 410 and sets it as a detection section candidate. When setting the detection section, the setting unit 451A sets the detection section in consideration of not only the shape of the road 101 but also information acquired from the other vehicle 200.

Specifically, the setting unit 451A confirms that the other vehicle 200 satisfies the following four conditions from the information of the other vehicle 200 acquired via the communication unit 70.
(1) The other vehicle 200 is performing automatic driving to control steering automatically.
(2) The other vehicle 200 is scheduled to pass the straight road extracted as the detection section.
(3) The other vehicle 200 can recognize which target it becomes.
(4) The distance between the host vehicle 100 and the other vehicle 200 is equal to or greater than a predetermined distance.

  The condition (1) is to confirm that the other vehicle 200 travels straight on the straight road as the own vehicle. The condition (2) is to confirm that there is no possibility that the other vehicle 200 will leave the detection section due to a turn or the like. Whether or not the other vehicle 200 leaves the detection zone can be confirmed by, for example, route information of the other vehicle 200. The condition (3) is intended to enable confirmation of which of the plurality of pieces of target information the target used for the detection of the angular deviation corresponds to when the plurality of pieces of target information are obtained. For example, the setting unit 451A acquires position information of the other vehicle 200. The condition (4) is that if the distance is too short, a sufficient amount of information can not be obtained for detecting the angular displacement, so that a sufficient amount of information can be secured for performing the detection of the angular displacement. It is. The distance to each other can be calculated from, for example, position information of the host vehicle 100 and the other vehicle 200.

  Note that setting unit 451A changes the minimum distance between host vehicle 100 and other vehicle 200 necessary for detecting an angle deviation according to the size of other vehicle 200, and sets a detection section. Is preferred. As a result, as in the first embodiment in which a stationary object is used as a determination criterion of angular deviation, variation in target information generated by another vehicle 200 having a large size is reduced, and accumulation is performed for angular deviation detection. The accuracy of target information can be improved. The size of the other vehicle 200 is included in, for example, information acquired via the communication unit 70. For example, it is determined that passenger cars and trucks are different in size.

  In detail, setting unit 451 A is between own vehicle 100 and other vehicle 200 that is required for detecting the angle deviation, as compared with the case where the width in the predetermined direction of other vehicle 200 is narrow is larger. Shorten the minimum distance. For example, when the width in the left-right direction of the other vehicle 200 is the first width, the setting unit 451A sets the minimum distance necessary for detecting the angular deviation as the first distance, and the width in the left-right direction of the other vehicle 200 Is a second width narrower than the first width, the minimum distance required for detecting the angular deviation is a second distance shorter than the first distance.

  In other words, the setting unit 451A sets a smaller value for the constant distance of the condition (4) than when the width in the left-right direction of the other vehicle 200 is narrow. According to this configuration, it is possible to secure target distance for detecting an angular deviation while securing a sufficient distance to another vehicle 200 having a large width where the variation of the reflection point becomes large. For this reason, the accuracy of the stored information can be improved.

  Setting unit 451A sets a detection zone when finding other vehicle 200 satisfying conditions (1) to (4) while host vehicle 100 is traveling on a straight road. When the detection section is set, calculation unit 452A starts acquiring target information on condition that self-vehicle 100 is performing automatic driving. The subsequent calculation process of the deviation angle is the same as that of the calculation unit 452 of the first embodiment. The calculating unit 452A calculates the magnitude of the angular deviation based on the trajectory of the other vehicle 200 acquired from the target information.

  In the present embodiment, angular deviation is detected using target information acquired when the vehicle 100 automatically drives a straight road. Although the other vehicle 200 which is a moving object is used to detect the angle deviation, the other vehicle 200 is also traveling on a straight road by automatic driving. For this reason, it is possible to prevent the steering wheel from being turned off in the own vehicle 100 and the other vehicle 200 during the detection of the angular deviation, and it is possible to accurately detect the angular deviation. In addition, since the steering wheel can be avoided from being turned off during the detection of the angular deviation, it is possible to reduce the probability that re-detection of the angular deviation will occur. Further, in the present embodiment, the angular deviation can be detected even in a place where there are few reflectors (for example, the desert etc.).

  In the present embodiment, the angular deviation is detected using an oncoming vehicle, but the angular deviation may be detected using another vehicle traveling at different speeds in the same direction. However, using an oncoming vehicle can increase the distance in a short time, and can detect an angular deviation quickly. In addition, the own vehicle 100 and the other vehicle 200 may calculate mutual deviation angles using the mutual vehicles as targets for detecting the angular deviation.

<< 3. Notes >>
The configurations of the embodiments and modifications shown herein are merely illustrative of the present invention. The configurations of the embodiment and the modifications may be appropriately changed without departing from the technical concept of the present invention. Moreover, several embodiment and modification may be implemented in combination as much as possible.

  In the embodiment described above, at least a part of the functional units realized as software by arithmetic processing of a CPU according to a computer program may be realized by an electrical hardware circuit. In addition, each functional unit is a conceptual component, and the function performed by one component is distributed to a plurality of components, or the function of a plurality of components is integrated into a single component. Good.

  Further, in the embodiment described above, the radar device is the FMCW type radar device, but other types of radar devices may be used. For example, a fast-chirp modulation (FCM) radar apparatus may be used.

  Furthermore, the present invention is characterized in that the angular deviation of the sensor is detected using automatic operation and high-accuracy three-dimensional map information. In the embodiment described above, the sensor is a millimeter wave radar device. However, this is merely an example, and the sensor for detecting the angular deviation may be, for example, a camera or a laser radar device.

  In addition, in order to set the detection section which can acquire target information for detecting an angle gap, you may use information other than high-precision three-dimensional map information. For example, the center server collects image information captured by a plurality of vehicles with a camera and target information detected by a radar device. Then, the center server derives a section that can be a detection section based on the collected information. The host vehicle 100 may acquire the information of the derived section and set it as the detection section. Further, the detection section may be set based on the target information acquired by the radar device of the vehicle 100.

  Also, until now, the detection interval was set in advance to detect the angle deviation, but the radar apparatus may detect the angle deviation based on the target information accumulated in the past without setting the detection interval. .

1, 5 ... radar device 60 ... automatic driving system 100 ... vehicle 102 ... roadside object (stationary object)
200: Other vehicle 410: Map information 451, 451A: Setting unit 452, 452A: Calculation unit

Claims (9)

A radar device mounted on a vehicle having an automatic driving system for automatically controlling steering,
A setting unit configured to set a detection section capable of acquiring target information for detecting an angle deviation of the own device;
A calculating unit that acquires the target information and calculates the magnitude of the angular deviation when the vehicle travels in the detection section during automatic driving;
Radar equipment.   The radar apparatus according to claim 1, wherein the setting unit sets the detection section based on map information having three-dimensional static information. The setting unit sets the detection section based on information on a road shape and a stationary object acquired from the map information,
The radar apparatus according to claim 2, wherein the calculation unit calculates the magnitude of the angular deviation based on a trajectory of the stationary object acquired from the target information. The setting unit sets the detection section based on information acquired from the map information and information acquired from another vehicle having the automatic driving system.
The radar apparatus according to claim 2, wherein the calculation unit calculates the magnitude of the angular deviation based on a trajectory of the other vehicle acquired from the target information.   The radar apparatus according to claim 4, wherein the other vehicle is an oncoming vehicle.   The setting unit changes the minimum distance between the vehicle and the stationary object or the other vehicle, which is necessary to detect the angular deviation, according to the size of the stationary object or the other vehicle. The radar apparatus according to any one of claims 3 to 5, wherein the detection section is set.   The radar apparatus according to claim 6, wherein the setting unit shortens the minimum distance compared to a case where the width of the stationary object or the other vehicle in the predetermined direction is narrow as compared with the case where the width is narrow.   The radar apparatus according to any one of claims 1 to 7, wherein a road shape of the detection section is a straight line shape. An information processing method in a radar device mounted on a vehicle having an automatic driving system for automatically controlling steering,
A setting step of setting a detection section capable of acquiring target information for detecting an angular deviation of the radar device;
Calculating the magnitude of the angular deviation by acquiring the target information when the vehicle travels in the detection section during automatic driving;
An information processing method comprising:

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