Radar signal processing device

Abstract

The present application provides a radar signal processing device capable of easily performing shaft deviation detection, shaft deviation amount estimation and correction. The radar signal processing device processes signals from a plurality of radars mounted on a vehicle, and includes: an object detection unit (170) that detects an object around the vehicle using a signal from a first radar among the plurality of radars and detects the object using a signal from a second radar among the plurality of radars; an object determination unit (183) that determines whether the objects detected by the first radar and the second radar are the same object based on a time difference in detection of the objects and a difference in distance to the objects (estimated inclination) detected by the first radar and the second radar; and a shaft deviation detection unit (185) that detects shaft deviation of the first radar or the second radar based on the difference in distance to the objects (estimated inclination) detected by the first radar and the second radar when the objects are determined to be the same object.

Description

TECHNICAL FIELD

[0001] The present application relates to a radar signal processing device, for example, to a radar system composed of a plurality of radar devices mounted on a vehicle and a radar signal processing device provided in the radar device. BACKGROUND

[0002] In recent years, systems such as an inter-vehicle distance alarm system, an adaptive cruise control, a collision damage mitigation brake, and the like are mounted on a vehicle to ensure the safety of a driver or a pedestrian.

[0003] A millimeter wave radar for a vehicle is one of sensors that detects the outside situation (estimates distance, speed, angle, reflection intensity, and the like as object information around the vehicle) in real time in the above-described system, transmits an electric wave toward a space and receives a reflection wave reflected from an object, and performs signal processing to thereby estimate the object information.

[0004] Each company is promoting the development of a surrounding monitoring system that mounts such a millimeter wave radar for a vehicle at different positions (for example, mounts two units at the front corners, mounts two units at the rear corners, and the like) of a vehicle, thereby enabling real-time monitoring of the environment around the vehicle and issuing an alarm to a driver or performing emergency braking based on the detected information (see Patent Literature 1).

[0005] PRIOR ART DOCUMENT

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Laid-Open No. 2015-078925 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, after the vehicle on which the radar is mounted is delivered, the vehicle posture changes over time or the radar itself deteriorates, which causes a deviation between the radar emission axis of the radar device (hereinafter, sometimes referred to simply as a radar) such as a millimeter wave radar for a vehicle and the vehicle travel direction axis.

[0010] This axis deviation can cause an error in the estimation of the object information around the radar by the radar and adversely affect the vehicle control at the rear stage of the radar.

[0011] For example, consider a situation in which a preceding vehicle is traveling on the same lane as the own vehicle on a highway. At this time, in a case where the radar emission axis has deviated, the position of the preceding vehicle can be erroneously estimated as if it is on the adjacent lane even though it is on the same lane as the own vehicle.

[0012] The present application has been made in view of the above-described circumstances, and has an object to provide a radar signal processing device capable of easily performing detection of axis deviation, and estimation and correction of an axis deviation amount in a radar system using a plurality of radar devices mounted on a vehicle.

[0013] Technical means for solving the problem

[0014] To solve the above-described problem, the radar signal processing device of the present application is a radar signal processing device that processes signals from a plurality of radars mounted on a vehicle, characterized by comprising: a target detection section that detects a target around the vehicle using a signal from a first radar among the plurality of radars, and detects the target using a signal from a second radar among the plurality of radars; a target determination section that determines whether the target is the same target based on a time difference in detection of the target by the first radar and the second radar, and a difference in distance to the target detected by the first radar and the second radar; and an axis deviation detection section that detects axis deviation of the first radar or the second radar based on the difference in distance to the target detected by the first radar and the second radar in a case where the target is determined to be the same target.

[0015] Effects of the Invention

[0016] According to the present application, the detection of axis deviation, and the estimation and correction of an axis deviation amount described above can be achieved by comparing the inclination of the target information, i.e., wall detection information, detected by each radar, and each information at the time of detection.

[0017] The above-described problems, configurations, and effects will be made clear by the following embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A block diagram showing the overall configuration of the radar device of the present embodiment.

[0019] Figure 2 A configuration diagram of a surrounding monitoring system using the radar device 100 shown in Fig. 1. Figure 1

[0020] A processing flowchart of the aiming processing section 180 in the radar device 100 shown in Fig. 1. Figure 3 Figure 1 A schematic diagram for explaining the principle of the present embodiment (without radar axis deviation).

[0021] Figure 4 A schematic diagram for explaining the principle of the present embodiment (with radar axis deviation).

[0022] Figure 5

[0023] ​​Figure 6 A graph showing the relationship between the amount of axis deviation of the radar and the amount of deviation of the inclination of the straight line or plane of the wall detection.

[0024] Figure 7 A diagram showing a case where the detection ranges of the radar 100a and the radar 100c overlap. DETAILED DESCRIPTION

[0025] Hereinafter, an embodiment of the present application will be described in detail with reference to the accompanying drawings.

[0026] 〈Radar Apparatus〉

[0027] Figure 1 The overall configuration of the radar apparatus of the present embodiment is shown.

[0028] The radar apparatus 100 of the illustrated embodiment is configured by a millimeter wave radar, a LIDAR, a sonar, or the like, and basically has a transmission section 101, a reception section 103, a radar signal processing section (radar signal processing apparatus) 105, and a transceiver control section 110. The transmission section 101 includes a modulation processing section 120 and a transmission antenna 130. The reception section 103 includes a reception antenna 140 and a demodulation processing section 150. The radar signal processing section 105 includes a frequency analysis section 160, a target detection section 170, and a boresight processing section 180.

[0029] Further, the boresight processing section 180 has an applicable condition judging section 181, a target judging section 183, an axis deviation detection section 185, an axis deviation radar discriminating section 187, and an axis deviation amount estimation-correction section 189. Furthermore, the radar signal processing section (radar signal processing apparatus) 105 is configured in the form of a computer having a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), or the like. Each function of the radar signal processing section (radar signal processing apparatus) 105 is realized by the processor executing a program stored in the ROM. The RAM stores data including intermediate data of the operation under the program executed by the processor.

[0030] The radar device 100 first performs phase modulation or frequency modulation in the modulation processing section 120 according to the method, pulls up the carrier frequency of the resulting electric wave toward a specific frequency band such as the 77 GHz band, and then transmits it toward the space via the transmission antenna 130. The electric wave reflected from the target in the surroundings is received with the reception antenna 140, pulled down to the frequency band of the baseband signal that can be analyzed by signal processing using the transmission wave in the demodulation processing section 150, and converted to digital data (signal) by signal amplification, filter processing, and AD conversion. The transceiver control section 110 is provided to control the operation of the modulation processing section 120 and the demodulation processing section 150.

[0031] The converted digital data (signal) is input to the frequency analysis section 160 of the radar signal processing section 105, and the distance, velocity, and angle of the target in the surroundings are inferred from the frequency spectrum after Fourier transform toward the distance direction, velocity direction, and angle direction (hereinafter, these are sometimes referred to as target information).

[0032] The inferred target information is input to the target detection section 170, and the inference accuracy of the target information is improved by considering not only the currently inferred target information but also the past target information. Further, the processing content of the target detection section 170 (of the tracking and wall detection processing) is described in detail later.

[0033] Next, the detection of the radar axis deviation is performed in the aiming processing section 180, the axis deviation amount is inferred in the case of axis deviation, the CAN output is performed after the correction of the axis deviation degree to the target information of the target detection section 170, and the information is transmitted to the ECU (vehicle control section) 200 of the subsequent stage.

[0034] That is, the aiming processing section 180 first performs the execution determination of the axis deviation detection processing (applicability determination) in the applicability determination section 181. The same target determination of the target information (wall detection information) detected by the radar device 100 and the other radar device 100' is performed in the target determination section 183 only in the case where the applicability condition is satisfied in the applicability determination section 181.

[0035] In the case where the same target is determined in the target determination section 183, the two target information (wall detection information) determined as the same target are compared in the axis deviation detection section 185, and the detection or determination of the presence or absence of the axis deviation is performed. In the case where the axis deviation is determined in the axis deviation detection section 185, the axis deviation radar is discriminated in the axis deviation radar discrimination section 187, for example, according to the confidence degree given to the target information (wall detection information) of each radar. Further, the inference of the axis deviation amount of the radar determined by the discrimination of the axis deviation radar and the correction of the target information of the target detection section 170 are performed in the axis deviation amount inference-correction section 189, and the CAN output is performed.

[0036] Further, the processing contents of each section of the aiming processing section 180 will be described later in detail.

[0037] Further, the aiming processing section 180 of the present embodiment performs the axis deviation detection and the estimation of the axis deviation amount using the information detected by the other radar device 100' as described above, and therefore the detection information 100A' of the other radar device 100' (of the target detection section 170) is input to the aiming processing section 180 (of the target determination section 183).

[0038] Here, the detection information 100A' of the other radar device 100' (of the target detection section 170) is, for example, the inclination of a wall (calculated from the detected distance information) in the information identifying the wall, the detection time, and the like (described later), and the other radar device 100' is, for example, the rear left corner radar 100c (shown in Figure 2 ) in the case where the radar device 100 is provided as the front left corner radar 100a (shown in Figure 2 ).

[0039] 〈Surrounding monitoring system (radar system)〉

[0040] The internal processing of a single radar device is described in the above-mentioned 〈radar device〉. An example of a configuration of a surrounding monitoring system, which is a radar system of the radar device using a plurality of units (provided on a vehicle), is shown in Figure 2 . Figure 2 An example in which two units (100a and 100b) are mounted on the left and right corners in front of the vehicle, and two units (100c and 100d) are mounted on the left and right corners in the rear of the vehicle is shown in FIG. 1. As described later, in the present embodiment, the detection ranges of each radar device (front left corner radar 100a, front right corner radar 100b, rear left corner radar 100c, and rear right corner radar 100d) mounted on the vehicle 500 do not overlap. A system in which the information detected by each radar device 100a, 100b, 100c, and 100d is transmitted to the ECU 200 through the CAN bus 300, collision prediction with a surrounding target is performed inside the ECU 200, and a warning is given to the driver or emergency braking is performed according to the degree of danger of collision.

[0041] The radar signal processing section (radar signal processing device) 105 of the present embodiment is a processing device mounted in each radar device 100a, 100b, 100c, and 100d or concentratedly mounted in the ECU 200, and the mounting position is not limited. An example in the present embodiment is a case where it is mounted in each radar device 100a, 100b, 100c, and 100d.

[0042] 〈Radar signal processing section (radar signal processing device) 105〉

[0043] Next, the processing contents of each of the object detection section 170 and the aiming processing section 180 in the radar signal processing section 105 in the radar device 100 will be described with reference to Figure 1 and Figure 3

[0044] 〈Object detection section 170〉

[0045] The tracking and wall detection processing of the object detection section 170 in the radar signal processing section 105 of the radar device 100 will be described. The object detection section 170 first performs tracking processing, that is, tracks and detects an object (information) around the vehicle by considering not only the object information currently estimated by the frequency analysis section 160 but also past object information. Details of the tracking processing are omitted in the present specification because a conventional known technique can be employed. When the detected points after the tracking processing satisfy the following conditions, the object detection section 170 considers that a structure such as a wall or a guardrail exists around the vehicle, and thus outputs wall detection information to the CAN. Further, the so-called wall detection information described here indicates the inclination of the detected wall or the detection time information. That is, the object detection section 170 detects data indicating a plane as a wall according to the distance to the object (detected point) after the tracking processing, and outputs the angle of the detected plane (data) (corresponding to the inclination of the wall) and the detection time to the CAN as the wall detection information.

[0046] 《Conditions for wall detection》

[0047] • The detected points are arranged at equal intervals and in the longitudinal (vertical) direction

[0048] • The detected points are from a stationary object

[0049] 〈Aiming processing section 180〉

[0050] A flowchart of the aiming processing section 180 in the radar signal processing section 105 of the radar device 100 is shown in Figure 3 . The aiming processing section 180 takes as main input information the detection information 100A estimated in the radar device 100 and the detection information 100A' estimated in the other radar device 100'. Here, the so-called radar device 100 indicates, for example, the front left corner radar 100a, the so-called other radar device 100' indicates the rear left corner radar 100c (see Figure 2 ), and the detection information 100A and 100A' indicates the wall detection information (the inclination of the detected line and the detection time) detected in the tracking and wall detection processing of the object detection section 170 of each radar.

[0051] As Figure 3 ​As shown, the aiming processing section 180 is configured of a total of five processing blocks of the applicability condition determination S301 performed by the applicability condition determination section 181, the same target determination S303 performed by the target determination section 183, the axis deviation detection S305 performed by the axis deviation detection section 185, the axis deviation radar determination S307 performed by the axis deviation radar determination section 187, and the axis deviation amount estimation and correction S309 performed by the axis deviation amount estimation and correction section 189, and before the initial processing related to the target, the same target determination S303, is performed, the execution determination processing of the axis deviation detection processing, the applicability condition determination S301, is performed.

[0052] (Applicability Condition Determination S301: Applicability Condition Determination Section 181)

[0053] Before the same target determination S303 is performed, the determination of whether the applicability conditions for the execution of the axis deviation detection processing are satisfied is performed in the applicability condition determination S301. Only in the case where all the applicability conditions are satisfied (S302: YES), the processing proceeds to the same target determination S303, and in the case where the applicability conditions are not satisfied (S303: NO), all the processing after the same target determination S303 is skipped.

[0054] The present embodiment effectively utilizes the wall detection information of the radar to perform the axis deviation detection and estimation. Thus, in the case where the present embodiment is used in a state where the accuracy of the wall detection information of the radar is poor, there is a risk of causing a malfunction (false axis deviation detection, etc.).

[0055] Therefore, the present embodiment is used only in a case where the accuracy of the wall detection information is relatively high. The applicability conditions of the present embodiment, which are determined in the applicability condition determination S301, and the setting bases of each of the applicability conditions are shown below.

[0056] (Applicability Conditions of the Present Embodiment)

[0057] (a) Wall detection information exists for both the front radar and the rear radar

[0058] (b) The yaw rate is equal to or lower than a predetermined value or the steering angle is equal to or lower than a predetermined value

[0059] (c) The own vehicle speed is equal to or higher than a predetermined value

[0060] (Setting Bases of the Applicability Conditions)

[0061] (a) Wall detection information exists for both the front radar and the rear radar

[0062] The present embodiment is to use the wall detection information to perform the detection of the axis deviation of the radar and the estimation of the axis deviation amount, and thus the existence of the information is a prerequisite condition for the present embodiment.

[0063] (b) The yaw rate is equal to or lower than a predetermined value or the steering angle is equal to or lower than a predetermined value

[0064] The accuracy of the wall detection information can deteriorate when the host vehicle is turning due to the following reasons. Thus, the condition (b) is provided to exclude the case where the host vehicle is turning from the application range of the embodiment (in other words, to set the straight-ahead state as the application range of the embodiment).

[0065] • The accuracy of the state determination of the object (determination of a moving object or a stationary object) deteriorates

[0066] • The wall or guardrail is detected obliquely, resulting in erroneous axis deviation detection

[0067] On the other hand, although the state determination of the object and the wall detection can also be performed while considering the yaw rate or the like when the host vehicle is turning, it is considered that the accuracy cannot be guaranteed as much as when the host vehicle is straight ahead, so the present application condition is provided.

[0068] (c) The speed of the host vehicle is a predetermined value or more

[0069] The present application condition is provided from the viewpoint that the accuracy of the same object determination S303 of the rear stage deteriorates rather than the accuracy of the wall detection information. The time difference Δt from when the front radar detects the wall to when the rear radar detects the wall described in the same object determination S303 described later becomes a function of the vehicle speed Vsv, and is in an inverse proportional relationship in which the larger Vsv is, the smaller Δt is, and the smaller Vsv is, the larger Δt is.

[0070] Thus, in the case where the vehicle speed is low (or stopped), Δt becomes large, so it is considered that the possibility that the object detected by the front radar and the object detected by the rear radar are not the same object increases.

[0071] For example, assume that the host vehicle is straight ahead at a vehicle speed of 3 km / h (Vsv = 3 km / h), the vehicle length is 5 m (Lsv = 5 m), and the length of the detected wall is 4 m (Lwall = 4 m). Δt is calculated to be 10.8 seconds using the formula (1) described later.

[0072] In the case where, for example, another vehicle obliquely intrudes into the detection range of the rear left corner radar 100c of the host vehicle at substantially the same vehicle speed within 10.8 seconds, the wall detection results of the front radar and the rear radar can differ, and thus erroneous axis deviation detection can occur.

[0073] As described above, the present application condition is provided to prevent erroneous axis deviation detection.

[0074] That is, in the applicable condition determination S301, execution determination of the shaft deviation detection processing of the radar is performed based on the vehicle information related to the behavior of the vehicle (yaw rate, steering angle, vehicle speed), the wall detection information as the object information detected by the radar, to prevent erroneous shaft deviation detection.

[0075] (Same object determination S303: object determination section 183)

[0076] In the same object determination S303, determination is made as to whether the wall detection information detected by the radar device 100 (front left corner radar 100a) and the other radar device 100' (rear left corner radar 100c) is the same object. Figure 4 A schematic diagram for explaining the present processing is shown. Figure 4 The left drawing of FIG. 10 shows a situation in which a certain section of a guardrail is detected by the front left corner radar 100a at an arbitrary time t [sec] while the vehicle 500 is traveling at a certain speed Vsv [km / h]. Figure 4 The right drawing of FIG. 10 shows a situation in which the "same section" as the certain section of the guardrail detected by the front left corner radar 100a described above is detected by the rear left corner radar 100c at a time t + At [sec] after At seconds from the left drawing. In the present embodiment, the detection range of the radar 100a and the detection range of the radar 100c do not overlap, but the vehicle 500 moves within At seconds so that the certain section of the guardrail crosses the detection range of the radar 100a and the detection range of the radar 100c.

[0077] Here, the guardrail is a stationary object, and the own vehicle speed is known, so the time difference At from when the guardrail is detected by the radar 100a to when the guardrail is detected by the radar 100c can be calculated using the following equation (1). Here, Lwall represents the length of the section of the guardrail detected by the radar 100a, Lsv represents the length in the traveling direction of the vehicle, and Vsv represents the vehicle speed. Further, the following calculation equation (1) is for the case where the left end of the detection range of the radar 100a (the direction of the sector of the front left corner of FIG. 10) is parallel to the front surface of the vehicle, and the left end of the detection range of the radar 100c (the direction of the sector of the rear left corner of FIG. 10) is parallel to the back surface of the vehicle. The calculation equation differs depending on the setting angle of the radar. Figure 4 Figure 4

[0078] [Equation 1]

[0079]

[0080] Here, if each radar detects the same object, the difference between the time when the guardrail is detected by the radar 100a and the time when the guardrail is detected by the radar 100c should be approximately equal to At. ​​

[0081] Thus, in the same object determination S303, in a case where the above-described two conditions of the comparison of the wall detection time difference and Δt are satisfied at the same time, it is determined that the information detected by the radar 100a and the information detected by the radar 100c are the same object.

[0082] (a) The wall detection time difference of the radar 100a and the radar 100c ≒ Δt

[0083] (b) The difference in the inclination of the wall detection by the radar 100a and the radar 100c < a predetermined value 1

[0084] Here, the wall detection time difference (= the difference between the time detected by the radar 100a and the time detected by the radar 100c) of the radar 100a and the radar 100c and the difference in the inclination of the wall detection can be calculated from the detection time and the inclination of the wall included in the wall detection information (detection information 100A, detection information 100A') detected by the radar 100a and the radar 100c.

[0085] That is, in the same object determination S303, it is determined whether the object is the same object based on the difference in the time at which the object is detected by the front left corner radar 100a and the rear left corner radar 100c and the difference in the inclination calculated from the distance to the object detected by the front left corner radar 100a and the rear left corner radar 100c.

[0086] In a case where it is determined that the information detected by the radar 100a and the radar 100c is the same object (S304: Yes), the process shifts to the axis deviation determination S305, and in a case where it is not determined that the same object (S304: No), the process ends after skipping the process after the axis deviation determination S305.

[0087] (Axis deviation determination S305: Axis deviation detection section 185)

[0088] In the axis deviation determination S305, the two pieces of wall detection information (the inclination of the straight line or the plane) determined to be the same object are compared, and thus the detection or determination of the presence or absence of the axis deviation is performed.

[0089] In a case where the difference in the inclination of the straight line or the plane < a predetermined value 2, it is determined that there is no axis deviation (S306: No), and the process ends. On the other hand, in a case where the difference in the inclination of the straight line or the plane ≥ a predetermined value 2, it is determined that there is an axis deviation (S306: Yes), and the process shifts to the axis deviation radar discrimination S307.

[0090] Here, the predetermined value 2 for discrimination is smaller than the predetermined value 1 in the same object determination S303, and in a case where the difference in the inclination of the straight line or the plane exceeds the predetermined value 2, it is determined that there is an axis deviation (S306: YES), and in a case where it does not exceed, it is determined that the difference in the inclination of the straight line or the plane is within the range of the detection error of the radar and there is no axis deviation (S306: NO).

[0091] Figure 5 A schematic diagram for explaining the present processing when only the rear left corner radar 100c has an axis deviation is shown. In a case where an axis deviation has occurred, as shown in Figure 5 , the straight line or the plane of the wall detection result appears to have an inclination of the amount of axis deviation.

[0092] That is, in the axis deviation determination S305, in a case where it is determined in the same object determination S303 that the object is the same object, the axis deviation of the front left corner radar 100a or the rear left corner radar 100c is detected based on the difference in the inclination calculated from the distances to the object detected by the front left corner radar 100a and the rear left corner radar 100c (in other words, the difference in the angle of the plane detected by the front left corner radar 100a and the plane detected by the rear left corner radar 100c).

[0093] (Axis deviation radar discrimination S307: Axis deviation radar discrimination section 187)

[0094] After the axis deviation of the radar is detected in the axis deviation determination S305, in the axis deviation radar discrimination S307, first, the confidence of the output data is given to the wall detection information of the radar. Then, the wall detection information with high confidence is regarded as positive, and the wall detection information with low confidence is regarded as having an axis deviation, and thus the radar having an axis deviation is discriminated.

[0095] For example, in addition to Figure 2 a vehicle configuration as described above, a radar that monitors the side of the vehicle (side radar) is provided on the side of the vehicle. In this case, an area in which the detection ranges overlap between the front radar and the side radar (hereinafter, this overlapping area is referred to as a common area) is generated. In the common area, the front radar and the side radar acquire detection information for the same object, respectively, and thus the difference in these detection information can be said to be smaller than the detection accuracy of the radar. Thus, in a case where the difference in the wall detection information detected in the common area is smaller than the detection accuracy of the radar, the possibility that the same axis deviation has occurred in both the front radar and the side radar is low, and thus it is considered that the reliability of the wall detection information is high and the confidence is increased.

[0096] Further, by regarding the wall detection information of the radar with high confidence as positive, it is possible to determine that the radar that has generated the wall detection information of the other radar with relatively low confidence has an axis deviation.

[0097] The method of assigning the confidence level is not limited to the present method, and for example, a method of assigning a confidence level in accordance with an AND condition with detection information of another sensor other than a radar is also considered.

[0098] (Shaft deviation amount estimation and correction S309: Shaft deviation amount estimation / correction section 189)

[0099] In the shaft deviation amount estimation and correction S309, in the case where the shaft deviation has occurred, estimation and correction of the shaft deviation amount (shaft deviation angle) of the radar in which the shaft deviation has occurred, which is determined in the shaft deviation radar determination S307, is performed. The relationship between the shaft deviation amount 189a of the radar and the deviation amount 189b of the inclination of the straight line or the plane detected by the wall detection is shown in FIG. 18. Figure 6 .

[0100] Figure 6 Suppose a case where the rear left corner radar 100c is disposed at a prescribed angle θ and the shaft deviation of the angle φ has occurred in the counterclockwise direction is depicted. According to Figure 6 , the shaft deviation amount 189a of the radar is equal to the deviation amount 189b of the inclination of the straight line or the plane detected by the wall detection, and thus the shaft deviation amount of the radar can be estimated from the deviation amount of the inclination of the straight line or the plane detected by the wall detection.

[0101] In the correction of the object detection information, by rotating the object detection position and the velocity vector by the estimated shaft deviation amount 189a of the radar (in the opposite direction), the apparent shaft deviation can be corrected.

[0102] <Effects>

[0103] As described above, the radar signal processing section (radar signal processing device) 105 of the present embodiment, which processes signals from a plurality of radars mounted on a vehicle, has: an object detection section 170 that detects an object around the vehicle using a signal from a first radar among the plurality of radars and detects the object using a signal from a second radar among the plurality of radars; an object determination section 183 that determines whether the object is the same object based on a time difference in which the object is detected by the first radar and the second radar and a difference in distance (difference in inclination calculated from the distance) to the object detected by the first radar and the second radar; and a shaft deviation detection section 185 that detects shaft deviation of the first radar or the second radar based on the difference in distance (difference in inclination calculated from the distance) to the object detected by the first radar and the second radar in the case where the object is determined to be the same object.

[0104] Further, the distance to the object is data indicating a plane, and the shaft deviation of the first radar or the second radar is detected based on a difference in angle (inclination) of the plane detected by the first radar and the plane detected by the second radar.

[0105] Further, a confidence level of output data is given to each of the plurality of radars, and in a case where the axis deviation is detected, which of the first radar or the second radar has the axis deviation is determined based on the confidence level.

[0106] According to the present embodiment, the detection of the axis deviation, and the estimation and correction of the axis deviation amount can be achieved by comparing the inclination of the target information, i.e., the wall detection information, and the time of detection of each of the radars. In other words, the detection of the axis deviation of the radars and the estimation of the axis deviation amount can be achieved by comparing the target information, i.e., the wall detection information, and the time of detection of each of the radars.

[0107] (Variation)

[0108] Figure 7 A schematic view is shown when the detection ranges of the radars 100a and 100c overlap.

[0109] In the example shown in FIG. 1, the detection ranges of the radars 100a and 100c overlap, and in the present embodiment, the detection of the axis deviation of the radars can be achieved regardless of whether or not there is a common region as shown in FIG. 1. Figure 7 In the example shown in FIG. 1, the detection ranges of the radars 100a and 100c overlap, and in the present embodiment, the detection of the axis deviation of the radars can be achieved regardless of whether or not there is a common region as shown in FIG. 1. Figure 7 The detection of the axis deviation of the radars can be achieved regardless of whether or not there is a common region as shown in FIG. 1.

[0110] In the known example of Patent Document 1, each radar observes the same target in the common region, and the axis deviation of the radars is detected by comparing the observed information. This point of observing the same target is the same in the present embodiment, but by comparing the inclination of the straight line or the plane, or the like, which is the relative information that does not depend on the coordinates, and the difference in the time of detection with the known value (Δt described in Embodiment 1), the same target can be observed by each radar even if there is no common region.

[0111] Further, the present application includes various variations, and is not limited to the above-described embodiments. For example, the above-described embodiments are detailed descriptions made in order to explain the present application in an easy-to-understand manner, and are not necessarily limited to having all the configurations described.

[0112] Further, each of the configurations, functions, processing sections, processing methods, and the like described above can be implemented in part or all of them by hardware, for example, by designing using an integrated circuit. Further, each of the configurations, functions, and the like described above can be implemented in software by a processor interpreting and executing a program that implements each function. The program, table, file, and the like information that implements each function can be placed in a storage device such as a memory, a hard disk, an SSD (Solid State Drive), or the like, or an IC card, an SD card, a DVD, or the like.

[0113] Furthermore, control lines and information lines are shown as deemed necessary for explanation, and not all control lines and information lines are necessarily shown on the product. In fact, it can be considered that almost all of the configurations are connected to each other.

[0114] Symbol Explanation

[0115] 100 … Radar device

[0116] 100A … Detection information (radar device)

[0117] 100a … Front left corner radar

[0118] 100b … Front right corner radar

[0119] 100c … Rear left corner radar

[0120] 100d … Rear right corner radar

[0121] 100' … Other radar device

[0122] 100A' … Detection information (other radar device)

[0123] 101 … Transmission section

[0124] 103 … Reception section

[0125] 105 … Radar signal processing section (radar signal processing device)

[0126] 110 … Transceiving control section

[0127] 120 … Modulation processing section

[0128] 130 … Transmission antenna

[0129] 140 … Reception antenna

[0130] 150 … Demodulation processing section

[0131] 160 … Frequency resolution section

[0132] 170 … Target detection section

[0133] 180 … Aiming processing section

[0134] 181 … Applicable condition determination section

[0135] 183 … Target determination section

[0136] 185 … Axis deviation detection section

[0137] 187 … Axis deviation radar determination section

[0138] 189 … Axis deviation amount estimation-correction section

[0139] 189a … amount of axis deviation of the radar

[0140] 189b … amount of deviation of the inclination of the straight line or plane detected by the wall detection

[0141] 200 … ECU (vehicle control section)

[0142] 300 … CAN bus

[0143] 500 … vehicle

Claims

1. A radar signal processing device that processes signals from a plurality of radars mounted on a vehicle, characterized by, Possessing: an object detection unit that detects an object around the vehicle using a signal from a first radar of the plurality of radars and detects the object using a signal from a second radar of the plurality of radars; an object determination unit that determines whether the object is the same object based on a time difference at which the object is detected by the first radar and the second radar during travel of the vehicle and a difference in inclination of a straight line or a plane calculated using distances to the object detected by the first radar and the second radar; and an axis deviation detection unit that, in a case where the object is determined to be the same object, detects an axis deviation of the first radar or the second radar based on the difference in inclination of the straight line or the plane calculated using the distances to the object detected by the first radar and the second radar, in the object determination unit, in a case where the time difference is approximately equal to a known value and the difference in inclination of the straight line or the plane is less than a first predetermined value, the object is determined to be the same object, in the axis deviation detection unit, in a case where the difference in inclination of the straight line or the plane is less than a second predetermined value that is smaller than the first predetermined value, it is determined that there is no axis deviation, and in a case where the difference in inclination of the straight line or the plane is equal to or greater than the second predetermined value, it is determined that there is an axis deviation.

2. The radar signal processing device according to claim 1, wherein a detection range of the first radar and a detection range of the second radar do not overlap.

3. The radar signal processing device according to claim 2, wherein movement of the vehicle causes the object to cross the detection range of the first radar and the detection range of the second radar.

4. The radar signal processing device according to claim 3, wherein the distance to the object is data indicating a plane, and the axis deviation of the first radar or the second radar is detected based on a difference in angle of the plane detected by the first radar and the plane detected by the second radar.

5. The radar signal processing device according to claim 1, wherein a confidence level of output data is assigned to each of the plurality of radars, and in a case where the axis deviation is detected, it is determined which of the first radar and the second radar has the axis deviation based on the confidence levels.

6. The radar signal processing device according to claim 1, wherein an execution determination of an axis deviation detection process of the first radar or the second radar is made based on vehicle information related to behavior of the vehicle or object information detected by the radars.

7. The radar signal processing device according to claim 6, wherein the execution determination of the axis deviation detection process of the first radar or the second radar is made based on a yaw rate, a steering angle, or a vehicle speed of the vehicle.

8. The radar signal processing device according to claim 1, wherein ​ The object determination unit determines whether the object detected by the first radar and the second radar is the same object by comparing a time difference between a time at which the object is detected by the first radar and a time at which the object is detected by the second radar and a time difference between a time at which the object is detected by the first radar and a time at which the length of the object divided by the vehicle speed of the vehicle is detected.

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