Radar axis misalignment variation abnormality determination device

Abstract

To provide a variation abnormality determination device of an axis deviation which can determine an abnormality when such an abnormality that an axis deviation angle varies due to the variation of the axis deviation angle occurs.SOLUTION: There is provided a variation abnormality determination device of an axis deviation of a radar device including a control device which estimates an angle formed by the reference direction and the central axis of the radar wave as an axis deviation angle αh and determines a variation abnormality of the axis deviation for the radar device which detects a target by radiating the radar wave in the direction of being apart from a vehicle and detecting the reflection wave. The control device: estimates the axis deviation angle αh for each preset time (S30); calculates a standard deviation σh of the plurality of axis deviation angles (S50); and determines that a variation abnormality of the axis deviation occurs (S100) when determination that the standard deviation exceeds a preset reference value σhc is performed continuously over a preset reference number of times Chc (S60-S90).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an apparatus for determining an abnormality in the variation of an axis misalignment of a radar device mounted on a vehicle such as an automobile. [Background technology]

[0002] A radar device mounted on a vehicle such as an automobile emits radar waves in a predetermined direction, such as ahead of the vehicle, and receives the waves reflected by a three-dimensional object. Information indicating the distance between the vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle, and so forth, is obtained based on the phase difference between the emitted radar waves and the reflected waves, the attenuation level of the reflected waves, and the time between the emission of the radar waves and the reception of the reflected waves. To obtain accurate information such as the distance between the vehicle and the three-dimensional object and to properly execute vehicle control, such as vehicle-to-vehicle distance control, based on the obtained information, it is necessary for the central axis of the radar waves to be accurately aligned with the predetermined direction and for the central axis to not deviate from the predetermined direction, i.e., there to be no axis misalignment.

[0003] One known device for estimating the axis misalignment of a radar device is one that estimates the axis misalignment based on information about stationary reflection points where radar waves are reflected by stationary objects, such as the axis misalignment estimation device described in Patent Document 1. In particular, the axis misalignment estimation device described in Patent Document 1 calculates the reliability of the estimated axis misalignment angle, and when correcting the axis misalignment of the radar device based on the axis misalignment angle, determines whether or not to correct the axis misalignment based on the reliability.

[0004] This type of axis deviation estimation device can estimate the axis deviation angle of the radar device, and when the reliability of the axis deviation angle is high, can correct the axis deviation of the radar device based on the estimated axis deviation angle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-187022 Summary of the Invention

[0006] [Problem to be solved by the invention] If the radar device is not properly attached to the vehicle body during shipping or maintenance of the vehicle, or if the radar device is detached in the field, mounting screws or the like may become loose. As a result, the radar device may repeatedly move relative to the vehicle body due to vibrations caused by the vehicle's travel. In such a situation, the axis misalignment angle fluctuates, and even an axis misalignment estimation device such as the one described in Patent Document 1 cannot estimate the axis misalignment angle, and the degree of variation in the axis misalignment angle cannot be estimated.

[0007] A primary object of the present invention is to provide an axis misalignment variation abnormality determination device that can determine whether an abnormality occurs in the axis misalignment angle when the abnormality occurs and the axis misalignment angle varies due to fluctuations in the axis misalignment angle.

[0008] [Means for solving the problems and effects of the invention] According to the present invention, there is provided an axis misalignment variation abnormality determination device (100) for a radar device that emits radar waves (millimeter waves 108) in a direction away from a vehicle (102) and detects a target by detecting the reflected waves, the device including a control device (driving assistance ECU 10) that estimates an angle between a reference direction (102A) and a central axis (106) of the radar waves as an axis misalignment angle (αh) and determines an axis misalignment variation abnormality based on the estimated axis misalignment angle.

[0009] The control device (driving assistance ECU 10) Axis misalignment angle At preset times Recommended (S30), and the standard deviation (σh) of the estimated multiple axis misalignment angles is calculated. At preset times The calculated standard deviation is calculated (S50), and it is determined that the calculated standard deviation exceeds a preset reference value (σhc). , a constant positive integer greater than 1 More than the preset number of times consecutivelyWhen this is done (S60 to S90), it is determined that an abnormality in the variation of the axis misalignment has occurred (S100).

[0010] As described above, if the screws or the like that attach the radar device to the vehicle body become loose, the radar device will repeatedly move relative to the vehicle body due to vibrations that occur as the vehicle travels, causing the estimated axis deviation angle to fluctuate. As a result, the standard deviation of the axis deviation angle will increase, and by comparing the standard deviation of the axis deviation angle with a reference value, it can be determined whether or not an abnormality in the variation of the axis deviation has occurred.

[0011] When the radar device repeatedly moves relative to the vehicle body and the estimated axis deviation angle fluctuates, the standard deviation continues to exceed the preset reference value. At preset times The standard deviation is calculated and it is judged that it exceeds the preset reference value. , a constant positive integer greater than 1 More than the preset number of times consecutively When the abnormality in the variation of the axis misalignment is detected, it is determined that the abnormality in the variation of the axis misalignment has occurred.

[0012] In the above description, to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses for the configurations of the invention corresponding to those embodiments. However, each component of the present invention is not limited to the components of the embodiments corresponding to the names and / or symbols enclosed in parentheses. Other objects, features, and attendant advantages of the present invention will be easily understood from the following description of the embodiments of the present invention, which will be given with reference to the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram illustrating an axis shift variation abnormality determination device for a radar device according to an embodiment of the present invention; [Figure 2] 4 is a flowchart illustrating a control routine for determining an abnormality in variation of an axis misalignment in the embodiment. [Figure 3] FIG. 2 is a diagram illustrating a millimeter wave radiation range of a radar device. [Figure 4] FIG. 10 is a diagram illustrating a method for estimating a horizontal axis deviation angle αh of a radar device. [Figure 5] 10 is a graph showing an example in which no steady axis misalignment occurs, the variation in the instantaneous value of the axis misalignment angle αh is small, and the standard deviation σh is smaller than the reference value σhc. [Figure 6] 10 is a graph showing an example in which no steady axis misalignment occurs, the instantaneous values ​​of the axis misalignment angle αh vary greatly, and the standard deviation σh is larger than the reference value σhc. [Figure 7] 10 is a graph showing an example in which a steady axis misalignment occurs, the variation in the instantaneous value of the axis misalignment angle αh is small, and the standard deviation σh is smaller than the reference value σhc. [Figure 8] 10 is a graph showing an example in which a steady axis misalignment occurs, the instantaneous values ​​of the axis misalignment angle αh vary greatly, and the standard deviation σh is larger than the reference value σhc. [Figure 9] 10 is a flowchart showing a control routine for determining an abnormality in variation of an axis misalignment in a first modified example. [Figure 10] 10 is a flowchart showing a control routine for determining an abnormality in variation of axis misalignment in a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Embodiment] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An axis misalignment variation abnormality determination device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. <Configuration>

[0015] As shown in Fig. 1, an axis misalignment variation abnormality determination device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving assistance ECU 10. The vehicle 102 is equipped with a drive ECU 20, a braking ECU 30, an electric power steering ECU 40, and a meter ECU 50. The ECU refers to an electronic control unit having a microcomputer as its main component. In the following description, the vehicle 102 will be referred to as the host vehicle 102 as necessary to distinguish it from other vehicles, and the electric power steering ECU will be referred to as the EPS ECU.

[0016] The microcomputer of each ECU includes a CPU, ROM, RAM, a read / write non-volatile memory (NVM), and an interface (I / F). The CPU performs various functions by executing instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are interconnected via a Controller Area Network (CAN) 104 to enable data exchange (communication). Therefore, the detected values ​​of sensors (including switches) connected to a specific ECU are transmitted to other ECUs.

[0017] The driving assistance ECU 10 is a central control device that performs driving assistance control such as adaptive cruise control, lane keeping control, etc. In the embodiment, the driving assistance ECU 10 functions as a control device that executes control to determine an abnormality in the variation of the axis misalignment of the radar device, as will be described in detail later.

[0018] The driving assistance ECU 10 is connected to a camera sensor 12 and a radar sensor 14. The camera sensor 12 and the radar sensor 14 function as surrounding information detection devices that detect information about targets and the like around the vehicle 102.

[0019] Although not shown, the camera device of the camera sensor 12 includes a camera unit that captures an image of the area ahead of the vehicle 102, and a recognition unit that analyzes image data captured by the camera unit to recognize targets such as white lines on the road and other vehicles. The recognition unit supplies information about the recognized targets to the driving assistance ECU 10 at predetermined time intervals. Note that a LiDAR (Light Detection and Ranging) may be used instead of the camera sensor 12.

[0020] The radar sensor 14 includes a radar device 14A equipped with a radar transmitter / receiver and a signal processor (not shown). The radar transmitter / receiver emits millimeter-wave band radio waves (hereinafter referred to as "millimeter waves") ahead of the vehicle 102 and receives millimeter waves reflected by three-dimensional objects (e.g., other vehicles, bicycles, guardrails, etc.) within the emission range (i.e., reflected waves). The signal processor acquires information indicating the distance between the vehicle and the three-dimensional object, the relative speed between the vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object relative to the vehicle, etc., based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, the time from transmitting the millimeter waves to receiving the reflected waves, etc., at predetermined time intervals and supplies the information to the driving assistance ECU 10.

[0021] 3, the radar device 14A is installed in the center of the front end of the vehicle 102, and the radar transmitter / receiver unit emits millimeter waves 108 forward along a central axis 106. The radiation range of the millimeter waves 108 is an angular range of φh / 2 (φh is a positive constant) on both the left and right sides of the central axis, covering an overall angular range of φh. When the radar device 14A is properly installed, the central axis 106 is aligned with the longitudinal center line 102A of the vehicle 102, which is the reference direction when viewed from above the vehicle 102, and is aligned with the straight forward direction of the vehicle 102.

[0022] Although not shown in the figure, the radiation range of the millimeter waves 108, when viewed from the side of the vehicle 102, is an angular range of φv / 2 (φv is a positive constant) on both the upper and lower sides of the central axis 106, for an overall angular range of φv. When the radar device 14A is properly installed, the central axis 106 is aligned with the longitudinal centerline 102A of the vehicle and extends substantially horizontally. The radiation range of the millimeter waves in a cross section perpendicular to the central axis 106 is circular or elliptical.

[0023] A drive unit 22 that accelerates the vehicle 102 by applying drive force to drive wheels not shown in Fig. 1 is connected to the drive ECU 20. Under normal circumstances, the drive ECU 20 controls the drive unit 22 so that the drive force generated by the drive unit 22 changes in response to the driving operation by the driver, and when a command signal is received from the driving assistance ECU 10, the drive ECU 20 controls the drive unit 22 based on the command signal.

[0024] The drive device 22 is not limited to a combination of an internal combustion engine and an automatic transmission. That is, the drive device 22 may be any drive device known in the art, such as a combination of an internal combustion engine and a continuously variable transmission, a so-called hybrid system which is a combination of an internal combustion engine and a motor, a so-called plug-in hybrid system, a combination of a fuel cell and a motor, or a motor.

[0025] The brake ECU 30 is connected to a brake device 32 that applies braking force to wheels (not shown in Fig. 1) to decelerate the vehicle 102. The brake ECU 30 normally controls the brake device so that the braking force generated by the brake device 32 changes in response to the braking operation by the driver, and when it receives a command signal from the driving assistance ECU 10, it controls the brake device 32 based on the command signal to perform automatic braking. When braking force is applied to the wheels, a brake lamp (not shown in Fig. 1) is turned on.

[0026] An EPS device 42 is connected to the EPS-ECU 40. The EPS-ECU 40 controls the steering assist torque and reduces the driver's steering burden by controlling the EPS device 42 in a manner known in the art based on the steering torque Ts and vehicle speed V detected by a driving operation sensor 60 and a vehicle state sensor 70, which will be described later. The EPS-ECU 40 also controls the EPS device 42 to steer the steered wheels as needed. Thus, the EPS-ECU 40 and the EPS device 42 function as a steering device that automatically steers the steered wheels as needed.

[0027] A display 52 is connected to the meter ECU 50. The display 52 displays the status of control by the driving assistance ECU 10, the result of the axis misalignment variation abnormality determination of the radar device 14A, etc. The display 52 may be, for example, a head-up display or a multi-information display that displays meters and various information, or may be a display of a navigation device.

[0028] The driving operation sensors 60 and the vehicle condition sensors 70 are connected to the CAN 104. Information detected by the driving operation sensors 60 and the vehicle condition sensors 70 (referred to as sensor information) is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be used appropriately by each ECU. Note that the sensor information may be information from a sensor connected to a specific ECU and transmitted to the CAN 104 from that specific ECU.

[0029] The driving operation sensor 60 includes a driving operation amount sensor that detects the amount of accelerator pedal operation, a braking operation amount sensor that detects the master cylinder pressure or the force applied to the brake pedal, a brake switch that detects whether the brake pedal is operated, a steering angle sensor that detects the steering angle θ, a steering torque sensor that detects the steering torque Ts, etc.

[0030] The vehicle state sensor 70 includes a vehicle speed sensor that detects the vehicle speed V of the vehicle 102, a longitudinal acceleration sensor that detects the longitudinal acceleration of the vehicle, a lateral acceleration sensor that detects the lateral acceleration of the vehicle, and a yaw rate sensor that detects the yaw rate of the vehicle.

[0031] In this embodiment, the ROM of the driving assistance ECU 10 stores a program for axis shift variation abnormality determination control of the radar device 14A corresponding to the flowchart shown in FIG. 2, and the CPU executes axis shift variation abnormality determination control in accordance with the program. <Axis Misalignment Variation Abnormality Determination Control Routine in the Embodiment>

[0032] Next, a shaft misalignment variation abnormality determination control routine in this embodiment will be described with reference to the flowchart shown in Fig. 2. The shaft misalignment variation abnormality determination control according to the flowchart shown in Fig. 2 is executed by the CPU of the driving assistance ECU 10 when an ignition switch (not shown in Fig. 1) is turned on. Repeat at preset intervals It will be executed. This also applies to the control according to the flowcharts shown in FIGS. 9 and 10, which will be described later. In the following description, the control for determining an abnormality in variation in shaft misalignment will be simply referred to as “this control.” At the start of the control, a count value Ch of a counter (described later) is initialized to 0.

[0033] First, in step S10, the CPU determines whether the vehicle 102 is traveling. If the CPU determines negative, it temporarily terminates this control, and if the CPU determines positive, it proceeds to step S20. Note that it may be determined that the vehicle is traveling when the vehicle speed V detected by the vehicle speed sensor of the vehicle state sensor 70 is equal to or greater than a reference value (a positive constant).

[0034] In step S20, the CPU determines whether or not the conditions for estimating the horizontal axis deviation angle αh of the radar device 14A are met. If the CPU determines negative, it temporarily terminates this control, and if the CPU determines positive, it proceeds to step S30.

[0035] In this case, it may be determined that the conditions for estimating the axis deviation angle αh are met when no excessive lateral force or longitudinal force is acting on the vehicle 102 and the change in the lateral force or longitudinal force is not excessive. This may be determined by checking whether the absolute values ​​of the steering angle and its derivative are equal to or less than reference values, or whether the absolute value of the vehicle's yaw rate and its derivative are equal to or less than reference values. Furthermore, whether the vehicle is in a substantially constant speed state may be determined by checking whether the absolute value of the derivative of the vehicle speed is equal to or less than reference values, or whether the absolute value of the vehicle's longitudinal acceleration and its derivative are equal to or less than reference values.

[0036] In step S30, the CPU estimates the angle (inclination angle in the y-axis direction) formed between the front of the vehicle 102 (x-axis direction) and the central axis 106 of the millimeter wave 108 as the horizontal axis deviation angle αh of the radar device 14A, as shown in Fig. 4. The axis deviation angle αh is assumed to be a positive value when the axis deviation angle is an inclination angle to the right of the vehicle 102, and a negative value when the axis deviation angle is an inclination angle to the left of the vehicle 102. Note that the axis deviation angle αh may be estimated in a known manner similar to the method for estimating the axis deviation angles αv and αh in Patent Document 1 mentioned above, for example.

[0037] In step S40, the CPU determines whether the number Nh of estimated axis deviation angles αh is equal to or greater than Nc (a positive fixed integer). If the CPU determines negative, it temporarily terminates this control, but if the CPU determines positive, it proceeds to step S50.

[0038] In step S50, the CPU calculates the standard deviation σh for the axis deviation angle αh of Nh according to the following equation (1): In the following equation (1), αhi (i=1 to Nh) is the value (instantaneous value) of each axis deviation angle αh, and αha is the average value of the axis deviation angle αh of Nh.

number

[0039] In step S60, the CPU determines whether the standard deviation σh is greater than a preset reference value σhc, where σhc is a positive constant. If the CPU makes a positive determination, it increments the counter value Ch by 1 in step S70, and then proceeds to step S90. On the other hand, if the CPU makes a negative determination, it resets the counter value Ch to 0 in step S80, and then temporarily terminates the control.

[0040] In step S90, the CPU determines whether the count value Ch of the counter is equal to a preset reference value Chc ( greater than 1 If the CPU makes a negative determination, it temporarily ends this control, and if the CPU makes a positive determination, it causes this control to proceed to step S100.

[0041] In step S100, the CPU determines that an abnormality in the horizontal axis shift variation has occurred in the radar device 14A, and outputs a command signal to the meter ECU 50 to display an alarm indicating that an abnormality in the horizontal axis shift variation has occurred in the radar device 14A on the display device 52. Note that, in addition to the alarm being displayed on the display device 52, an audible alarm indicating that an abnormality in the axis shift variation has occurred may also be output from a speaker not shown in FIG.

[0042] As can be seen from the above explanation, when the vehicle 102 is traveling (S10) and conditions are met that enable estimation of the horizontal axis deviation angle αh of the radar device 14A (S20), the horizontal axis deviation angle αh of the radar device 14A is estimated (S30). When the number Nh of estimated axis deviation angles αh becomes equal to or greater than Nhc (S40), the standard deviation σh is calculated for the Nh axis deviation angles αh (S50).

[0043] When it is determined that the standard deviation σh is smaller than the reference value σhc, or when it is determined that the standard deviation σh is larger than the reference value σhc, continuousWhen the number of times Ch that the measurement is performed is less than a preset reference value Chc (S60 to S90), it is not determined that an abnormality in the horizontal axis deviation variation has occurred in the radar device 14A.

[0044] In contrast, the standard deviation σh is determined to be larger than the reference value σhc. continuous When the number of times Ch that the measurement is performed is equal to or greater than a preset reference value Chc (S60 to S90), it is determined that an abnormality in the horizontal axis deviation variation has occurred in the radar device 14A, and an alarm indicating the occurrence of the abnormality is displayed on the display 52 (S100). <Example of estimated results for axis misalignment angle αh>

[0045] Next, examples of the estimation results of the axis deviation angle αh will be described with reference to Fig. 5 and Fig. 6. Fig. 5 and Fig. 6 are graphs showing examples of the estimation results of the axis deviation angle αh when there is no abnormality in the horizontal axis deviation variation of the radar device 14A and when there is an abnormality in the horizontal axis deviation variation, respectively. In Fig. 5 and Fig. 6, the horizontal axis represents the instantaneous value of the estimated axis deviation angle αh, and the vertical axis represents the frequency. This also applies to Fig. 7 and Fig. 8, which will be described later.

[0046] 5, the variation in the instantaneous value of the axis misalignment angle αh is small, and the standard deviation σh is smaller than the reference value σhc. Therefore, a negative determination is made in step S60, and it is not determined that an abnormality in the variation of the axis misalignment has occurred.

[0047] 6, the instantaneous value of the axis misalignment angle αh varies greatly, and the standard deviation σh is greater than the reference value σhc. Therefore, a positive determination is made in step S60, and when this positive determination is made Chc times or more in succession, a positive determination is made in step S90. Therefore, in step S100, it is determined that an axis misalignment variation abnormality has occurred, and an alarm to the effect that an axis misalignment variation abnormality has occurred is displayed on the display 52.

[0048] 5 and 6, the median αhm and average value αha of the instantaneous values ​​of the axis deviation angle αh are close to 0. Therefore, it is considered that the central axis 106 of the millimeter wave 108 of the radar device 14A is substantially aligned with the longitudinal center line 102A of the vehicle 102, that is, no steady axis deviation occurs. However, in the example shown in Fig. 6, it is considered that the screws or the like that attach the radar device 14A to the vehicle body have loosened, and the central axis 106 is moving left and right with respect to the longitudinal center line 102A due to vehicle vibrations, etc.

[0049] 7 and 8 are graphs showing examples of the estimation results of the axis deviation angle αh when a steady axis deviation occurs, and when there is no abnormal variation in the horizontal axis deviation of the radar device 14A, similar to FIGS. 5 and 6, respectively.

[0050] 7 and 8 with those of 5 and 6, the median αhm and average value αha of the instantaneous values ​​of the axis shift angle αh are far from 0 in Figures 7 and 8. Therefore, it is considered that the central axis 106 of the millimeter wave 108 of the radar device 14A is not aligned with the longitudinal center line 102A of the vehicle 102, and a steady axis shift Δαh is occurring.

[0051] Therefore, in the example shown in Fig. 5, neither steady axis misalignment nor axis misalignment variation abnormality occurs, while in the example shown in Fig. 6, steady axis misalignment abnormality does not occur but axis misalignment variation abnormality is thought to have occurred. In the example shown in Fig. 7, steady axis misalignment abnormality occurs but axis misalignment variation abnormality does not occur, and in the example shown in Fig. 8, both steady axis misalignment abnormality and axis misalignment variation abnormality are thought to have occurred.

[0052] As can be seen from the above description, according to the embodiment, it is possible to determine not only whether or not a steady axis shift abnormality in the horizontal direction has occurred in the radar device 14A, but also whether or not an axis shift variation abnormality in the horizontal direction has occurred. Furthermore, when an axis shift variation abnormality in the horizontal direction has occurred, the occurrence of the axis shift variation abnormality can be notified to the occupants of the vehicle 102 by displaying the fact on the display 52.

[0053] [First Modification] FIG. 9 is a flowchart showing a control routine for determining an abnormality in the variation of the axis misalignment in the first modified example.

[0054] In the first modified example, the angle (vertical tilt angle) formed between the forward direction (horizontal direction) of the vehicle 102 and the central axis 106 of the millimeter wave 108 is estimated as the vertical axis deviation angle αv of the radar device 14A, and an abnormality in the variation of the vertical axis deviation is determined.

[0055] 9 and 2, steps S110 to S200 correspond to steps S10 to S100 in the embodiment, respectively, and steps S110 and S120 are executed in the same manner as steps S10 and S20 in the embodiment, respectively. In step S130, the vertical axis deviation angle αv of the radar device 14A is estimated, and in step S140, it is determined whether the number Nv of the estimated axis deviation angles αv is equal to or greater than Nc.

[0056] In step S150, the standard deviation σv of the axis deviation angle αv of Nv is calculated according to the following equation (2): In the following equation (2), αvi (i=1 to Nh) is the value (instantaneous value) of each axis deviation angle αv, and αva is the average value of the axis deviation angle αv of Nv.

number

[0057] In steps S160 to S190, it is determined that the standard deviation σv is greater than the reference value σvc (a positive constant). continuousThe number of times Cv is set to a preset reference value Cvc( greater than 1 Furthermore, if a positive determination is made in step S190, it is determined in step S200 that an abnormality in the variation of the vertical axis shift of the radar device 14A has occurred, and an alarm indicating the occurrence of the abnormality is displayed on the display 52.

[0058] Therefore, according to the first modification, it is possible to determine not only whether or not an abnormality in the vertical axis shift has occurred in the radar device 14A, but also whether or not an abnormality in the vertical axis shift variation has occurred. Furthermore, when an abnormality in the vertical axis shift variation has occurred, the fact can be displayed on the display 52, thereby notifying the vehicle occupants.

[0059] [Second Variation] Fig. 10 is a flowchart showing the main part of the control routine for determining an abnormality in variation of axis misalignment in the second modified example. Note that steps S10 and S20, which are not shown in Fig. 10, are executed in the same manner as steps S10 and S20 in the embodiment, respectively.

[0060] In the second modified example, the horizontal axis deviation angle αh and the vertical axis deviation angle αv of the radar device 14A are estimated, and abnormal variations in the horizontal and vertical axis deviations are determined.

[0061] As can be seen from a comparison of FIG. 10 with FIGS. 2 and 9, in step S30, the horizontal axis deviation angle αh and the vertical axis deviation angle αv of the radar device 14A are estimated, and in step S40, it is determined whether the number N of combinations of the estimated axis deviation angles αh and αv is equal to or greater than Nc.

[0062] In step S45, the square root of the sum of the squares of the axis deviation angles αh and αv is calculated as the horizontal and vertical axis deviation angles α of the radar device 14A, and in step S50, the standard deviation σ is calculated for the axis deviation angle α of Nv according to the following equation (3): In the following equation (3), αi (i = 1 to Nh) is the value (instantaneous value) of each axis deviation angle α, and αa is the average value of the axis deviation angle α of N.

number

[0063] In steps S60 to S90, it is determined that the standard deviation σ is greater than the reference value σc (a positive constant). continuous The number of times C is set to a predetermined reference value Cc ( greater than 1 Furthermore, if a positive determination is made in step S90, it is determined in step S100 that an abnormality in the horizontal and vertical axis deviation variations has occurred in the radar device 14A, and an alarm indicating the occurrence of the abnormality is displayed on the display 52.

[0064] Therefore, according to the second modification, it is possible to determine not only whether or not an abnormality in the horizontal or vertical axis shift has occurred in the radar device 14A, but also whether or not an abnormality in the variation in the horizontal and vertical (diagonal) axis shift has occurred. Therefore, even if the variation in the horizontal or vertical axis shift is not large, if the variation in the diagonal axis shift is large, the abnormality can be determined. Furthermore, when an abnormality in the variation in the diagonal axis shift has occurred, the fact can be displayed on the display 52, thereby notifying the vehicle occupants.

[0065] Although the present invention has been described in detail above with respect to a specific embodiment and two modifications, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiment and two modifications, and that various other embodiments are possible within the scope of the present invention.

[0066] For example, in the above-described embodiment and the first and second modified examples, the radar device 14A radiates millimeter waves forward of the vehicle 102, and the reference direction is the direction of the longitudinal center line 102A of the vehicle. However, the axial misalignment variation abnormality determination device of the present invention may be applied to a radar device that radiates millimeter waves in a direction other than the forward direction, such as backward of the vehicle.

[0067] In the above-described embodiment and the first and second modified examples, the radar device 14A is configured to emit millimeter waves as radar waves. However, the axis misalignment variation abnormality determination device of the present invention may be applied to a radar device that emits laser light as radar waves or a radar device that emits sound waves as radar waves.

[0068] Furthermore, in the above-described embodiment and the first and second modified examples, it is determined whether or not an axis misalignment variation abnormality has occurred, and if an axis misalignment variation abnormality has occurred, this is displayed on the display 52. ​​However, in addition to determining whether or not an axis misalignment variation abnormality has occurred, it may also be determined whether or not a steady axis misalignment abnormality has occurred based on the median value αhm or average value αha of the instantaneous values ​​of the axis misalignment angle αh, and if such an abnormality has occurred, this may be displayed on the display 52. [Explanation of symbols]

[0069] 10... driving assistance ECU, 12... camera sensor, 14... radar sensor, 20... drive ECU, 22... drive device, 30... braking ECU, 32... braking device, 40... EPS ECU, 42... EPS device, 50... meter ECU, 60... driving operation sensor, 70... vehicle state sensor, 100... axis misalignment variation abnormality determination device, 102... vehicle

Claims

[Claim 1] A radar device that detects targets by emitting radar waves in a direction away from a vehicle and detecting reflected waves includes a control device that estimates an angle between a reference direction and a central axis of the radar waves as an axis deviation angle and determines an axis deviation abnormality based on the estimated axis deviation angle, the control device is configured to estimate an axis misalignment angle at predetermined time intervals, calculate a standard deviation of the estimated axis misalignment angles at the predetermined time intervals, and determine that an axis misalignment variation abnormality has occurred when a determination that the calculated standard deviation exceeds a predetermined reference value is made consecutively a predetermined reference number of times or more, the predetermined reference number being a positive integer greater than 1,

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