Angle error estimation device and angle error estimation method

Abstract

To improve estimation accuracy of an angular error of a radar device.SOLUTION: A control unit 7 of a vehicle information providing device 1 calculates on the basis of observation angle information from the radar devices 3, 4, a vehicle speed detection signal and a yaw rate detection signal for each of a plurality of stationary objects detected, a stationary object inclination indicating a movement direction of the stationary object viewed from an own vehicle when it is assumed that the own vehicle is traveling straight, for each observation angle at which radar devices 3, 4 observe the stationary object. The control unit 7 classifies a plurality of stationary object inclinations calculated for each of a plurality of observation angles to calculate an average value (hereinafter referred to as an inclination average value) of the plurality of stationary object inclinations classified for each observation angle, for each observation angle. The control unit 7 calculates an angle error for each observation angle on the basis of a movement locus calculated based on a plurality of average values for each observation angle, and a reference movement locus set as the movement locus of the stationary object with no angle error.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an angle error estimation device and an angle error estimation method for estimating an angle error of a radar device. [Background technology]

[0002] Patent Document 1 describes a technology in which a radar device mounted on a vehicle observes the horizontal angle and relative speed of stationary objects near the vehicle while the vehicle is traveling, and estimates the angle error for each of multiple horizontal angles by considering deviations from an ideal curve as horizontal angle errors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2015 / 0070207 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of detailed investigation by the inventors, it was found that the technology described in Patent Document 1 has the problem that as a vehicle passes beside a stationary object and moves away from the stationary object, the change in speed relative to a change in horizontal angle becomes smaller, and the accuracy of estimating the angle error decreases.

[0005] The present disclosure aims to improve the accuracy of estimating angle errors in a radar device. [Means for solving the problem]

[0006] One aspect of the present disclosure is an angle error estimation device (7) that estimates an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1).

[0007] The angular error estimation device of the present disclosure includes a first information acquisition unit (S10), a second information acquisition unit (S20), a stationary object detection unit (S30), a movement direction calculation unit (S100), an average calculation unit (S210, S710), and an angular error calculation unit (S220 to S240, S720 to S800).

[0008] The first information acquisition unit is configured to acquire object detection information including at least position information indicating the position of an object present near the moving body from at least one radar device that includes the side of the moving body as an object detection area.

[0009] The second information acquisition unit is configured to acquire movement trajectory information for identifying a movement trajectory of the moving object. The stationary object detection unit is configured to detect a stationary object, which is an object that is stationary to the side of the moving object, based on the object detection information.

[0010] The movement direction calculation unit is configured to calculate, for each of the multiple stationary objects detected by the stationary object detection unit, a movement direction indication value that indicates the movement direction of the stationary object as seen from the moving body, assuming that the moving body is moving straight, for each observation angle at which the stationary object is observed by at least one radar device, based on the object detection information and movement trajectory information.

[0011] The average calculation unit is configured to classify the plurality of movement direction indication values ​​calculated by the movement direction calculation unit into a plurality of observation angles, and to calculate, for each observation angle, an average value of the plurality of movement direction indication values ​​classified by observation angle as an average movement direction value.

[0012] The angular error calculation unit is configured to calculate an angular error for each observation angle based on an average movement trajectory, which is a movement trajectory calculated based on multiple average values ​​of movement directions calculated for each observation angle, and a reference movement trajectory set as the movement trajectory of a stationary object in the absence of an angular error.

[0013] The angle error estimation device of the present disclosure configured in this manner calculates the angle error for each observation angle based on the average trajectory and the reference trajectory, and therefore can prevent a decrease in the accuracy of the angle error estimation when the vehicle moves away from a stationary object compared to when the angle error is calculated based on a change in speed in response to a change in the observation angle. As a result, the angle error estimation device of the present disclosure can improve the accuracy of the angle error estimation of the radar device.

[0014] Another aspect of the present disclosure is an angle error estimation method executed by an angle error estimation device (7) that estimates an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1).

[0015] In the angle error estimation method of the present disclosure, the angle error estimation device acquires object detection information, which includes at least position information indicating the position of an object present near the moving body, from at least one radar device that includes the side of the moving body as an object detection area.

[0016] In the angular error estimation method of the present disclosure, the angular error estimation device acquires movement trajectory information for identifying the movement trajectory of a moving object. In the angle error estimation method of the present disclosure, the angle error estimation device detects stationary objects, which are objects that are stationary to the side of the moving body, based on object detection information.

[0017] In the angle error estimation method of the present disclosure, the angle error estimation device calculates, for each of a plurality of detected stationary objects, a movement direction indication value that indicates the movement direction of the stationary object as seen from the moving object, assuming that the moving object is moving straight, for each observation angle at which the stationary object is observed by at least one radar device, based on the object detection information and movement trajectory information.

[0018] In the angle error estimation method disclosed herein, the angle error estimation device classifies the calculated multiple movement direction indication values ​​into multiple observation angles, and calculates, for each observation angle, the average value of the multiple movement direction indication values ​​classified by observation angle as the average movement direction value.

[0019] In the angle error estimation method disclosed herein, the angle error estimation device calculates an angle error for each observation angle based on an average movement trajectory, which is a movement trajectory calculated based on the average values ​​of multiple movement directions calculated for each observation angle, and a reference movement trajectory set as the movement trajectory of a stationary object in the absence of an angle error.

[0020] The angular error estimation method of the present disclosure is a method executed by the angular error estimation device of the present disclosure, and by executing this method, it is possible to obtain the same effects as the angular error estimation device of the present disclosure. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a block diagram showing a configuration of a vehicle information providing device; [Figure 2] 1 is a diagram showing an installation position of a radar device and an object detection area. FIG. [Figure 3] 3A and 3B are diagrams showing a left object detection area, a rear object detection area, and a right object detection area. [Figure 4] 10A and 10B are diagrams illustrating the principle of calculating an angle correction amount. [Figure 5] 10 is a flowchart showing a tilt calculation process. [Figure 6] FIG. 10 is a diagram illustrating a method for determining whether an object is stationary or not. [Figure 7] FIG. 10 is a diagram illustrating a method for calculating the tilt of a stationary object. [Figure 8] FIG. 10 is a diagram illustrating coordinate transformation of an observation angle. [Figure 9] FIG. 10 is a diagram illustrating components of a stationary object movement trajectory that are added by turning. [Figure 10] 5 is a flowchart showing an angle correction process according to the first embodiment. [Figure 11] 10 is a graph showing the average value of the tilt of stationary objects for each observation angle, and a graph showing the number of observations for each observation angle. [Figure 12] 1A and 1B are diagrams illustrating the basic principle of angular error calculation processing. [Figure 13]10 is a flowchart showing an angle error calculation process. [Figure 14] FIG. 10 is a diagram illustrating a method for calculating a radial distance. [Figure 15] 10 is a graph showing angle errors for each observation angle. [Figure 16] FIG. 10 is a diagram showing radar observation angles. [Figure 17] 10 is a graph showing the relationship between the radar observation angle and the angle error. [Figure 18] 10 is a flowchart illustrating a vehicle information providing process. [Figure 19] 10 is a flowchart showing an angle correction process according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] [First embodiment] A first embodiment of the present disclosure will be described below with reference to the drawings. 1, the vehicle information providing device 1 is mounted on a vehicle and includes a head-up display device 2, a left rear radar device 3, a right rear radar device 4, a vehicle speed sensor 5, a yaw rate sensor 6, and a control unit 7. Hereinafter, the vehicle on which the vehicle information providing device 1 is mounted is referred to as the host vehicle.

[0023] The head-up display device 2 irradiates display light for displaying an image from below the windshield toward the windshield, allowing the driver to visually recognize the projected virtual image superimposed on the actual scenery ahead of the vehicle.

[0024] The left rear radar device 3 and the right rear radar device 4 transmit radar waves toward the periphery of the vehicle and receive the reflected radar waves. Hereinafter, the left rear radar device 3 and the right rear radar device 4 will also be referred to as radar device 3 and radar device 4, respectively. The left rear radar device 3 and the right rear radar device 4 are installed at the left end and the right end of the rear of the vehicle, respectively.

[0025] The radar devices 3 and 4 employ, for example, the well-known FMCW system, alternately transmitting radar waves in an uplink modulation section and radar waves in a downlink modulation section at a preset modulation period T, and receiving the reflected radar waves. As a result, the radar devices 3 and 4 detect, for each modulation period T, the distance to the point (hereinafter, observation point) from which the radar waves are reflected (hereinafter, observation point), the relative velocity from the observation point (hereinafter, observation point relative velocity), and the azimuth angle at which the observation point is located (hereinafter, observation point azimuth angle). The radar devices 3 and 4 also output observation point information indicating the observation point distance, observation point relative velocity, and observation point azimuth angle of the detected observation point to the control unit 7.

[0026] The vehicle speed sensor 5 detects the traveling speed v of the host vehicle and outputs a vehicle speed detection signal indicative of the detection result. The yaw rate sensor 6 detects the yaw rate ω of the host vehicle and outputs a yaw rate detection signal indicative of the detection result.

[0027] The control unit 7 is an electronic control device mainly composed of a microcomputer including a CPU 11, a ROM 12, a RAM 13, etc. Various functions of the microcomputer are realized by the CPU 11 executing a program stored in a non-transitory tangible recording medium. In this example, the ROM 12 corresponds to the non-transitory tangible recording medium storing the program. Furthermore, the execution of this program executes a method corresponding to the program. Note that some or all of the functions executed by the CPU 11 may be configured as hardware using one or more ICs, etc. Furthermore, the number of microcomputers constituting the control unit 7 may be one or more.

[0028] The control unit 7 executes various processes based on inputs from the radar devices 3, 4, the vehicle speed sensor 5, and the yaw rate sensor 6, and controls the head-up display device 2. Specifically, the control unit 7 determines whether or not a vehicle in an adjacent lane on the left or right side of the host vehicle is approaching from behind the host vehicle based on the detection results of the radar devices 3, 4, the vehicle speed sensor 5, and the yaw rate sensor 6, and if a vehicle is approaching, causes the head-up display device 2 to display a warning image indicating that a vehicle is approaching from behind on the left or right side.

[0029] 2, the left rear radar device 3 is installed inside the bumper at the left rear of the vehicle. The left rear radar device 3 detects surrounding vehicles that exist within the object detection area R1 by transmitting radar waves toward the rear of the vehicle.

[0030] The right rear radar device 4 is installed inside the bumper at the right rear of the vehicle. The right rear radar device 4 detects surrounding vehicles that exist within the object detection area R2 by transmitting radar waves toward the rear of the vehicle.

[0031] The left rear radar device 3 is mounted so that the center axis CA1 of the object detection area R1 faces in a direction tilted by an angle φ to the rear left with respect to the width direction Dw of the vehicle. The right rear radar device 4 is mounted so that the center axis CA2 of the object detection area R2 faces in a direction tilted by an angle φ to the rear right with respect to the width direction Dw of the vehicle.

[0032] 3, object detection region R1 includes a left object detection region R11 that detects objects on the left side of the host vehicle, a rear object detection region R12 that detects objects directly behind the host vehicle, and a right object detection region R13 that detects objects on the right side of the host vehicle. Like object detection region R1, object detection region R2 includes the left object detection region R11, the rear object detection region R12, and the right object detection region R13.

[0033] First, the principle of calculating the angle error in the radar devices 3 and 4 will be described. As described above, the radar devices 3 and 4 are installed inside the bumper, and therefore the radar waves emitted from the radar devices 3 and 4 pass through the bumper and are transmitted to the outside of the vehicle. If the surface of the bumper is curved, the radar waves are refracted by the bumper, causing a deviation in the transmitting and receiving directions of the radar waves, resulting in an angular error between the azimuth angle at which an object exists and the azimuth angle of the observation point observed by the radar devices 3 and 4.

[0034] 4, assume that a vehicle VH1 traveling straight passes a stationary vehicle VH2 (hereinafter referred to as the stationary vehicle VH2) on the right side. In this case, the movement trajectory of the stationary vehicle VH2 is a straight line, as indicated by the dashed line L1.

[0035] It is assumed that the left rear radar device 3 detects a plurality of observation points P1, P2, P3, P4, P5, and P6 associated with the vehicle VH2 over time. When an angle error occurs, as the host vehicle VH1 moves away from the stationary vehicle VH2, the difference between the lateral position of the observation point of the stationary vehicle VH2 observed by the left rear radar device 3 and the actual lateral position of the stationary vehicle VH2 becomes larger.

[0036] Observation point P1 is the position observed when the host vehicle VH1 passes directly beside the stationary vehicle VH2, and it is assumed that the lateral position of observation point P1 is the actual lateral position of the stationary vehicle VH2. Assuming the above, the actual lateral position of the stationary vehicle VH2 at the time when observation point P6 is observed is determined so that distances r1 and r2 are equal, and position P11 is located on dashed line L1, as shown by position P11. Distance r1 is the distance between observation point P6 and radar device 3. Distance r2 is the distance between position P11 and radar device 3.

[0037] As a result, the difference between the azimuth angle of the position P11 and the azimuth angle of the observation point P6 is calculated as the angle correction amount. Next, a description will be given of the procedure of the slope calculation process executed by the control unit 7. The slope calculation process is a process that is executed every time the modulation period T elapses while the control unit 7 is in operation.

[0038] When the tilt calculation process is executed, the CPU 11 of the control unit 7 first acquires observation point information from the radar devices 3 and 4 in S10, as shown in FIG. The CPU 11 acquires a vehicle speed detection signal from the vehicle speed sensor 5 and acquires a yaw rate detection signal from the yaw rate sensor 6 in S20.

[0039] In S30, CPU 11 determines whether the observation point corresponding to the observation point information acquired in S10 is a point where light is reflected by a stationary object. Specifically, as shown in Fig. 6, CPU 11 determines that the observation point is a point where light is reflected by a stationary object if the absolute value of (Vr-v x cosΘ) is close to 0, where Vr is the observation point relative speed, v is the traveling speed of the host vehicle, and Θ is the angle between the direction of a line connecting the observation point and radar device 3 or 4 and the traveling direction of the host vehicle.

[0040] 5, in S40, the CPU 11 determines whether or not the radar devices 3 and 4 have detected a stationary object based on the determination result in S30. If a stationary object has not been detected, the CPU 11 ends the tilt calculation process. On the other hand, if a stationary object has been detected, the CPU 11 calculates, in S50, the observation angle θ of the observation point corresponding to the observation point information acquired in S10. m As shown in Figure 7, the observation angle θ m is an angle in which the angle directly to the left of the vehicle is set to 0° and the counterclockwise direction is set to positive. Note that, for the purpose of commonality of functions, the CPU 11 performs coordinate transformation on the observation point of the stationary object detected by the radar device 4 as if it were data detected by the radar device 3, as shown in FIG. m is calculated and stored in the RAM 13.

[0041] 5, in S60, the CPU 11 increments the observation number for the corresponding observation angle (i.e., adds 1). The observation number for the observation angle is set for each of the radar devices 3 and 4. In this embodiment, the observation number is set for each of the observation angles of 0°, 1°, 2°, 3°, . . . , 179°, and 180°.

[0042] In S70, the CPU 11 determines whether the observation point corresponding to the observation point information acquired this time (hereinafter referred to as the current observation point) represents the same object as the observation point corresponding to the observation point information acquired last time (i.e., before the modulation period T) (hereinafter referred to as the previous observation point).

[0043] Specifically, based on the observation point information acquired last time, CPU 11 calculates the predicted position and predicted speed of the current observation point corresponding to the previous observation point, and if the difference between the predicted position and predicted speed and the observed position and observed speed of the current observation point is smaller than the predetermined upper limit position difference and upper limit speed difference, respectively, it determines that the current observation point represents the same object as the previous observation point.

[0044] If the current observation point does not represent the same object as the previous observation point, CPU 11 ends the tilt calculation process. On the other hand, if the current observation point represents the same object as the previous observation point, CPU 11 determines in S80 whether the vehicle's traveling speed v exceeds a preset first tilt determination value.

[0045] If the traveling speed v of the host vehicle is equal to or less than the first tilt determination value, the CPU 11 ends the tilt calculation process. On the other hand, if the traveling speed v of the host vehicle exceeds the first tilt determination value, the CPU 11 determines in S80 whether the absolute value of the yaw rate ω of the host vehicle is less than a preset second tilt determination value. If the absolute value of the yaw rate ω of the host vehicle is equal to or greater than the second tilt determination value, the CPU 11 ends the tilt calculation process.

[0046] On the other hand, if the absolute value of the yaw rate ω of the host vehicle is less than the second tilt determination value, the CPU 11 calculates the stationary object tilt in S100. As shown in FIG. 7, in a coordinate system in which the radar device 3 is the origin, the traveling direction of the vehicle is the X axis, and the direction perpendicular to the traveling direction is the Y axis, the X direction component of the observation position of the previous observation point is defined as x m (t-1), the Y-direction component of the observation position of the previous observation point is y m (t-1), the X-component of the observation position of the current observation point is x m (t), the Y-direction component of the observation position of the current observation point is y mLet (t) be the time when the current tilt calculation process is executed. Time (t-1) is the time when the previous tilt calculation process was executed. Also, let Δx and Δy be the X-direction component and the Y-direction component of the stationary object movement trajectory that are added when the host vehicle turns.

[0047] In this case, the CPU 11 calculates the observation angle θ of the previous observation point. m The observation angle θ m (t) is the observation angle θ m The tilt of the stationary object at (t) is calculated using equation (1).

[0048]

number

[0049] As shown in FIG. 9, assume that the host vehicle travels at a speed v and turns at a yaw rate ω between time (t-1) and time t. In this case, the host vehicle travels a distance equivalent to v×T along the traveling direction at time (t-1), and travels a distance equivalent to v×ω×T along a direction perpendicular to the traveling direction at time (t-1). 2 / 2. Furthermore, the host vehicle rotates horizontally by an angle equivalent to ω×T.

[0050] At time (t-1), a coordinate system CS1 is defined as a coordinate system with the radar device 3 as the origin, the traveling direction of the vehicle as the X axis, and a direction perpendicular to the traveling direction as the Y axis. At time t, a coordinate system CS2 is defined as a coordinate system with the radar device 3 as the origin, the traveling direction of the vehicle as the X axis, and a direction perpendicular to the traveling direction as the Y axis.

[0051] If the X- and Y-components of the position of a stationary object in coordinate system CS1 are x(t-1) and y(t-1), respectively, and the X- and Y-components of the position of a stationary object in coordinate system CS2 are x(t) and y(t), respectively, then equations (2) and (3) hold. ω×T×y(t) in equation (2) corresponds to Δx, and the right-hand side of equation (3) corresponds to Δy.

[0052]

number

[0053] As shown in FIG. 5, in S110, the CPU 11 compares the stationary object tilt calculated in S100 with the radar device that detected the observation point corresponding to the stationary object tilt (i.e., radar device 3 or radar device 4) and the observation angle θ m The data is stored in the RAM 13 in association with (t), and the inclination calculation process is terminated.

[0054] Next, the procedure of the angle correction process executed by the control unit 7 will be described. The angle correction process is a process that is executed every time a preset execution period (for example, one hour) elapses while the control unit 7 is operating. The angle correction process is executed for each of the radar device 3 and the radar device 4. The procedure of the angle correction process executed for the radar device 3 will be described below. The angle correction process executed for the radar device 4 has the same procedure as the angle correction process executed for the radar device 3.

[0055] When the angle correction process is executed, the CPU 11 of the control unit 7 first calculates the average value of the stationary object tilt for each observation angle in S210, as shown in Fig. 10. Specifically, the CPU 11 calculates the average value of the stationary object tilt for each observation angle for the multiple stationary object tilts stored in the process of S110 from the end of the previous angle correction process until the start of the current angle correction process. For example, m When N stationary object tilts are stored, the CPU 11 divides the sum of the N stationary object tilts by N and calculates the result as the observation angle θ m 11 shows the average value of the stationary object tilts for each observation angle for a plurality of stationary objects observed by the radar device 3.

[0056] 10, the CPU 11 sets a valid continuous interval in S220. Specifically, the CPU 11 sets the range of observation angles in which the number of observations is equal to or greater than a preset validity determination value (e.g., 500) as the valid continuous interval. Graph G2 in FIG. 11 shows the number of observations for each observation angle for multiple stationary objects observed by the radar device 3. In graph G2, the valid continuous interval AS1 of the radar device 3 is 64° to 88°, and the valid continuous interval AS2 of the radar device 3 is 94° to 113°.

[0057] 10, the CPU 11 determines whether the valid continuous section is valid at S230. Specifically, the CPU 11 determines whether the section length of the valid continuous section is equal to or greater than a preset valid continuous judgment value (e.g., 10°), and determines that the valid continuous section is valid if the section length is equal to or greater than the valid continuous judgment value.

[0058] If the valid continuous section is not valid, the CPU 11 ends the angle correction process. On the other hand, if the valid continuous section is valid, the CPU 11 executes the angle error calculation process in S240.

[0059] Here, the basic principle of the angle error calculation process will be explained. As shown in FIG. 12, in the angle error calculation process, when the host vehicle is traveling straight, the trajectory of a stationary object located 1 m away from the side of the host vehicle along a direction perpendicular to the traveling direction of the host vehicle is estimated.

[0060] When there is no angle error, the lateral position of the stationary object is constant at 1 m because the vehicle is traveling straight, and the shape of the trajectory is a straight line, as shown by the dashed line L11. However, in reality, due to an angle error, the shape of the trajectory is not a straight line, as shown by the solid line L12.

[0061] In the angular error calculation process, the angular error at any angle is calculated by comparing the trajectory predicted from the inclination of the stationary object trajectory with the trajectory without angular error. The dashed line L11 corresponds to the reference trajectory L11 described later. The solid line L12 corresponds to the average trajectory L12 described later.

[0062] Next, the procedure for calculating the angle error will be described. When the angle error calculation process is executed, the CPU 11 of the control unit 7 first sets the first angle command value n stored in the RAM 13 to 0 in S310, as shown in FIG.

[0063] In S320, the CPU 11 sets a first maximum angle command value K. Specifically, the CPU 11 subtracts the start angle value of the valid continuous section from the end angle value of the valid continuous section, and sets the result as the first maximum angle command value K. For example, since the valid continuous section AS1 is 64° to 88°, the first maximum angle command value K is 24.

[0064] In S330, the CPU 11 sets the radial distance r0 at angle θ0 of the valid continuous section to (1 / cos θ0). That is, in the angle error calculation process, it is assumed that the angle error is 0 up to the start angle of the valid continuous section.

[0065] In step S340, the CPU 11 calculates the observation angle θ n+1 Radial distance r at n+1 is calculated using equation (4). α in equation (4) is the observation angle θ n is the average tilt of stationary objects at

[0066]

number

[0067] As shown in FIG. 14, Equation (4) shows that the line extended from the previously calculated point CP1 with the stationary object tilt α is at an observation angle θ n+1 This corresponds to calculating the point CP2 where the line in the direction of the arrow intersects with the arrow. As shown in FIG. 13, the CPU 11 calculates the radius distance r n+1 is the radial distance r n Here, the radial distance r n+1 is the radial distance r n If it is equal to or less than this, the CPU 11 ends the angle error calculation process.

[0068] On the other hand, the radial distance r n+1 is the radial distance r n If it is longer, the CPU 11 calculates the angle error in step S360. Specifically, the CPU 11 calculates the true angle estimation value θ true Calculate the observation angle θ n+1 From the true angle estimate θ true The CPU 11 then stores the calculated angle error in the RAM 13 in association with the observation angle.

[0069]

number

[0070] In S370, the CPU 11 increments the first angle command value n. In S380, the CPU 11 determines whether the first angle command value n is equal to or greater than the first maximum angle command value K. If the first angle command value n is less than the first maximum angle command value K, the CPU 11 proceeds to S340. On the other hand, if the first angle command value n is equal to or greater than the first maximum angle command value K, the CPU 11 ends the angle error calculation process.

[0071] 13 shows the procedure for calculating the angle error in one valid continuous interval. However, in the angle error calculation process of S240, the CPU 11 calculates the angle error by executing the processes of S310 to S380 for each of the valid continuous intervals AS1 and AS2.

[0072] 10, after the angular error calculation process of S240 is completed, CPU 11 calculates the angular error in the observation angle between valid continuous interval AS1 and valid continuous interval AS2 by interpolation in S250. Specifically, CPU 11 calculates the angular error by drawing a straight line between the angular error at the maximum observation angle in valid continuous interval AS1 and the angular error at the minimum observation angle in valid continuous interval AS2.

[0073] For example, as shown in Figure 15, CPU 11 calculates the angle errors at observation angles of 89°, 90°, 91°, 92°, and 93° by drawing a straight line between the angle error AE1 at the maximum observation angle (i.e., 88°) within the valid continuous section AS1 and the angle error AE2 at the minimum observation angle (i.e., 94°) within the valid continuous section AS2.

[0074] After the process of S250 is completed, the CPU 11 creates an angle error table in S260 as shown in FIG. 10, and then ends the angle correction process. Specifically, the CPU 11 first converts the observation angle into an angle centered around the central axis CA1 of the radar device 3 (hereinafter, referred to as the radar observation angle). In the process of S260 in the angle correction process performed on the radar device 4, the CPU 11 converts the observation angle into an angle centered around the central axis CA2 of the radar device 4 (hereinafter, referred to as the radar observation angle). FIG. 16 shows the radar observation angle θ radar centered around the central axis CA2 of the radar device 4. That is, the observation angle within the effective continuous interval of the radar device 3 is converted into an angle centered around the central axis CA1 of the radar device 3, and the observation angle within the effective continuous interval of the radar device 4 is converted into an angle centered around the central axis CA2 of the radar device 4. The CPU 11 then creates an angle error table by setting a corresponding angle error for each of a plurality of radar observation angles.

[0075] Fig. 17 is a graph showing the relationship between the radar observation angle and the angular error in the radar device 3. The solid line in the graph of Fig. 17 shows the angular error calculated by the angular error calculation process. The dashed line in the graph of Fig. 17 shows the true value of the angular error.

[0076] Next, a description will be given of the procedure of the vehicle information provision process executed by the control unit 7. The vehicle information provision process is a process that is repeatedly executed while the control unit 7 is operating. When the vehicle information provision process is executed, the CPU 11 of the control unit 7 first determines at S510 whether new observation point information has been acquired from the radar devices 3 and 4, as shown in FIG. 18 . If observation point information has not been acquired, the CPU 11 terminates the vehicle information provision process. On the other hand, if observation point information has been acquired, the CPU 11 corrects at S520 the observation point azimuth angle indicated by the observation point information acquired at S510 based on the angle error table created at S260. That is, the CPU 11 identifies the radar observation angle corresponding to the observation point azimuth angle and extracts the angle error corresponding to this radar observation angle from the angle error table. The CPU 11 then corrects the observation point azimuth angle by adding the extracted angle error to the radar observation angle corresponding to the observation point azimuth angle.

[0077] At S530, the CPU 11 determines whether vehicles in the adjacent lanes on the left and right of the vehicle are approaching from behind the vehicle based on the observation point information acquired at S510, the observation point direction corrected at S520, and the detection results of the vehicle speed sensor 5 and the yaw rate sensor 6.

[0078] If a vehicle in the adjacent lane on the left or right of the host vehicle is not approaching the host vehicle from behind, the CPU 11 ends the vehicle information provision process. On the other hand, if a vehicle in the adjacent lane on the left or right of the host vehicle is approaching the host vehicle from behind, the CPU 11 displays, in S540, a warning image on the head-up display device 2 indicating that a vehicle is approaching from behind on the left or right, and ends the vehicle information provision process.

[0079] The control unit 7 of the vehicular information providing device 1 configured in this manner estimates an angle error, which is an error in the azimuth angle detected by the radar devices 3 and 4 mounted on the vehicle VH1. The control unit 7 acquires observation point information including at least the observation point distance and observation point azimuth angle indicating the position of an object present near the vehicle VH1 from radar devices 3 and 4, which include the sides of the vehicle VH1 as object detection areas R1 and R2.

[0080] The control unit 7 acquires a vehicle speed detection signal and a yaw rate detection signal for identifying the movement trajectory of the host vehicle VH1. The control unit 7 detects stationary objects, which are objects that are stationary to the sides of the vehicle VH1, based on the observation point information.

[0081] For each of the detected multiple stationary objects, the control unit 7 calculates the stationary object inclination, which indicates the direction of movement of the stationary object as seen from the host vehicle VH1, assuming that the host vehicle VH1 is traveling straight, for each observation angle at which the radar devices 3, 4 observed the stationary object, based on the observation point information, vehicle speed detection signal, and yaw rate detection signal.

[0082] The control unit 7 classifies the calculated multiple stationary object inclinations into multiple observation angles, and calculates, for each observation angle, an average value of the multiple stationary object inclinations classified by observation angle (hereinafter referred to as an average inclination value).

[0083] The control unit 7 calculates the angle error for each observation angle based on a movement trajectory L12 (hereinafter referred to as the average movement trajectory L12) calculated based on multiple average inclination values ​​calculated for each observation angle, and a reference movement trajectory L11 set as the movement trajectory of a stationary object when there is no angle error.

[0084] The control unit 7 calculates the angle error for each observation angle based on the average trajectory L12 and the reference trajectory L11, which can prevent a decrease in the accuracy of estimating the angle error when the host vehicle VH1 moves away from a stationary object compared to when the angle error is calculated based on a change in speed with respect to a change in the observation angle. This allows the control unit 7 to improve the accuracy of estimating the angle error of the radar devices 3 and 4.

[0085] Furthermore, when the number of stationary object tilts classified by observation angle (i.e., the number of observations) for each of the plurality of observation angles is equal to or greater than a predetermined validity determination value, the control unit 7 determines that the average tilt value of the observation angles is valid and sets a valid continuous section in which the observation angles for which the average tilt value is valid are continuous. Furthermore, when the section length of the valid continuous section is equal to or greater than the predetermined validity determination value, the control unit 7 calculates an average trajectory L12 based on the average tilt values ​​of the plurality of observation angles within the valid continuous section, and calculates an angle error for each of the plurality of observation angles within the valid continuous section.

[0086] Such a control unit 7 calculates the angle error by excluding the average tilt values ​​with a small number of observations, and therefore can suppress a decrease in the accuracy of estimating the angle error. Furthermore, the control unit 7 prohibits the calculation of the stationary object tilt when the traveling speed v of the host vehicle VH1 is equal to or less than a preset first tilt determination value. This prevents the control unit 7 from calculating the angle error using the stationary object tilt with a large error, and can prevent a decrease in the estimation accuracy of the angle error. This is because when the traveling speed v is low, the length of the movement trajectory of the stationary object becomes short, and the error in the stationary object tilt becomes large.

[0087] Furthermore, the control unit 7 prohibits the calculation of the stationary object tilt when the absolute value of the yaw rate ω of the host vehicle VH1 is equal to or greater than a predetermined second tilt determination value. This prevents the control unit 7 from calculating the angle error using the stationary object tilt with a large error, and can prevent a decrease in the estimation accuracy of the angle error. This is because when the yaw rate ω is large, it becomes difficult to accurately cancel the movement trajectory due to the turning of the host vehicle VH1.

[0088] The object detection region R1 of the radar device 3 includes a left object detection region R11 for detecting stationary objects on the left side of the host vehicle VH1, and a right object detection region R13 for detecting stationary objects on the right side of the host vehicle VH1.

[0089] The control unit 7 calculates the angle error for each observation angle corresponding to the left object detection region R11 of the radar devices 3 and 4 (i.e., the observation angle within the effective continuous section AS1). The control unit 7 also calculates the angle error for each observation angle corresponding to the right object detection region R13 of the radar devices 3 and 4 (i.e., the observation angle within the effective continuous section AS2). The control unit 7 calculates the angle error of the observation angle between the observation angle corresponding to the left object detection region R11 and the observation angle corresponding to the right object detection region R13 by interpolation using the angle error of the observation angle corresponding to the left object detection region R11 and the angle error of the observation angle corresponding to the right object detection region R13. This allows the control unit 7 to estimate the angle error in an angle range including the observation angle corresponding to directly behind the host vehicle VH1.

[0090] Furthermore, the control unit 7 uses the angle error to correct the observation point azimuth angle detected by the radar devices 3 and 4. This allows the control unit 7 to improve the accuracy of position detection of the radar devices 3 and 4.

[0091] In the embodiment described above, the control unit 7 corresponds to an angle error estimation device, the host vehicle VH1 corresponds to a moving body, S10 corresponds to processing as a first information acquisition unit, the observation point distance and observation point azimuth angle correspond to position information, and the observation point information corresponds to object detection information.

[0092] Furthermore, S20 corresponds to processing as a second information acquisition unit, the vehicle speed detection signal and the yaw rate detection signal correspond to movement trajectory information, S30 corresponds to processing as a stationary object detection unit, S100 corresponds to processing as a movement direction calculation unit, and the stationary object inclination corresponds to a movement direction indication value.

[0093] Moreover, S210 corresponds to the processing performed by the average calculation unit, the tilt average value corresponds to the movement direction average value, and S220 to S240 correspond to the processing performed by the angle error calculation unit. Furthermore, S80 corresponds to processing as a speed prohibition unit, and the first tilt determination value corresponds to a speed prohibition determination value. S90 corresponds to processing as a yaw rate prohibition unit, and the second tilt determination value corresponds to a yaw rate prohibition determination value.

[0094] Furthermore, radar device 3 corresponds to the left radar device, radar device 4 corresponds to the right radar device, S250 corresponds to the processing of an interpolation calculation unit, and S520 corresponds to the processing of an angle correction unit.

[0095] [Second embodiment] A second embodiment of the present disclosure will be described below with reference to the drawings. In the second embodiment, only the parts that are different from the first embodiment will be described. The same reference numerals will be used to designate common components.

[0096] The vehicular information providing device 1 of the second embodiment differs from the first embodiment in that the angle correction process is changed. Next, the procedure of the angle correction process of the second embodiment will be described.

[0097] When the angle correction process of the second embodiment is executed, the CPU 11 of the control unit 7 first calculates the average value of the stationary object tilt for each observation angle in S710, as in S210, as shown in FIG.

[0098] In S720, the CPU 11 sets the second angle command value q stored in the RAM 13 to 0. In step S730, the CPU 11 sets the radial distance r0 at the angle φ0 to (1 / cos θ0). 179 ,θ 180 correspond to 0°, 1°, 2°, , 179°, and 180°, respectively.

[0099] In step S740, the CPU 11 calculates the observation angle θ q+1 It is determined whether the number of observations at the observation angle θ is equal to or greater than a predetermined validity determination value (for example, 500). q+1 If the number of observations at is less than the validity determination value, the CPU 11 performs S750 to q+1 Radial distance r at q+1 (1 / cosθ q+1 ) and proceeds to S790. That is, the CPU 11 determines the observation angle θ q+1 The angular error at is set to 0.

[0100] On the other hand, the observation angle θ q+1 If the number of observations in is equal to or greater than the validity determination value, the CPU 11 performs step S760 to determine the observation angle θ q+1 Radial distance r at q+1 is calculated using equation (4).

[0101] In step S770, the CPU 11 calculates the radius distance r in the same manner as in step S350. q+1 is the radial distance r q Here, the radial distance r q+1 is the radial distance r q If the answer is no, the CPU 11 proceeds to S790.

[0102] On the other hand, the radial distance r q+1 is the radial distance r q If it is longer, the CPU 11 calculates the angle error in S780 in the same manner as in S360, and then proceeds to S790. In S790, the CPU 11 increments the second angle command value q.

[0103] In S800, the CPU 11 determines whether the second angle command value q is equal to or greater than the second maximum angle command value J (for example, 180). If the second angle command value q is less than the second maximum angle command value J, the CPU 11 proceeds to S740. On the other hand, if the second angle command value q is equal to or greater than the second maximum angle command value J, the CPU 11 creates an angle error table in S810 in the same manner as in S260, and ends the angle correction process.

[0104] The control unit 7 of the vehicle information providing device 1 configured in this manner determines that the average tilt value of the observation angles is valid when the number of multiple stationary object tilts classified by the observation angles (i.e., the number of observations) is equal to or greater than a predetermined validity determination value, calculates the average movement trajectory L12, and calculates the angle error corresponding to the observation angle. Since the control unit 7 calculates the angle error while excluding average tilt values ​​with a small number of observations, it is possible to suppress a decrease in the estimation accuracy of the angle error.

[0105] In the embodiment described above, S710 corresponds to the processing performed by the average calculation unit, the tilt average value corresponds to the movement direction average value, and S720 to S800 correspond to the processing performed by the angle error calculation unit.

[0106] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment and can be implemented in various modifications. The control unit 7 and the method described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit 7 and the method described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the control unit 7 and the method described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. The method for implementing the functions of each unit included in the control unit 7 does not necessarily need to include software; all of the functions may be implemented using one or more hardware components.

[0107] In the above embodiments, multiple functions of one component may be realized by multiple components, or one function of one component may be realized by multiple components. Furthermore, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0108] In addition to the control unit 7 described above, the present disclosure can also be realized in various forms, such as a system including the control unit 7 as a component, a program for causing a computer to function as the control unit 7, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and an angle error estimation method. [Technical idea disclosed in this specification] [Item 1] An angle error estimation device (7) that estimates an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1), a first information acquisition unit (S10) configured to acquire object detection information including at least position information indicating the position of an object present near the moving body from the at least one radar device that includes a side of the moving body as an object detection area; a second information acquisition unit (S20) configured to acquire movement trajectory information for identifying the movement trajectory of the moving object; a stationary object detection unit (S30) configured to detect a stationary object that is an object standing still beside the moving body based on the object detection information; a movement direction calculation unit (S100) configured to calculate, for each of the plurality of stationary objects detected by the stationary object detection unit, a movement direction indication value that indicates a movement direction of the stationary object as seen from the moving object on the assumption that the moving object is moving straight, for each observation angle at which the at least one radar device observes the stationary object, based on the object detection information and the movement trajectory information; an average calculation unit (S210, S710) configured to classify the plurality of movement direction indication values ​​calculated by the movement direction calculation unit into a plurality of observation angles, and to calculate, for each observation angle, an average value of the plurality of movement direction indication values ​​classified by the observation angle as a movement direction average value; an angle error calculation unit (S220 to S240, S720 to S800) configured to calculate the angle error for each observation angle based on an average movement trajectory, which is a movement trajectory calculated based on the plurality of average movement direction values ​​calculated for each observation angle, and a reference movement trajectory set as a movement trajectory of the stationary object when there is no angle error; An angle error estimation device comprising:

[0109] [Item 2] Item 1: An angle error estimation device according to item 1, The angle error estimation device, wherein the angle error calculation unit (S720 to S800) calculates the average movement trajectory by determining that the movement direction average value of the observation angle is valid when the number of the plurality of movement direction indication values ​​classified by the observation angle is equal to or greater than a predetermined validity determination value for each of the plurality of observation angles, and calculates the angle error corresponding to the observation angle.

[0110] [Item 3] Item 1: An angle error estimation device according to item 1, The angle error estimation device is configured such that, for each of the plurality of observation angles, if the number of the plurality of movement direction indication values ​​classified by the observation angle is equal to or greater than a predetermined validity determination value, the angle error calculation unit (S220 to S240) determines that the movement direction average value of the observation angle is valid and sets a valid continuous section in which the observation angles for which the movement direction average value is valid are continuous, and further, if the section length of the valid continuous section is equal to or greater than the predetermined validity determination value, calculates the average movement trajectory based on the movement direction average value of the plurality of observation angles within the valid continuous section, and calculates the angle error for each of the plurality of observation angles within the valid continuous section.

[0111] [Item 4] The angle error estimation device according to any one of items 1 to 3, An angle error estimation device comprising a speed prohibition unit (S80) configured to prohibit the movement direction calculation unit from calculating the movement direction indication value when the traveling speed of the moving body is equal to or less than a preset speed prohibition judgment value.

[0112] [Item 5] The angle error estimation device according to any one of items 1 to 4, An angle error estimation device comprising a yaw rate prohibition unit (S90) configured to prohibit the movement direction calculation unit from calculating the movement direction instruction value when the absolute value of the yaw rate of the moving body is equal to or greater than a predetermined yaw rate prohibition judgment value.

[0113] [Item 6] The angle error estimation device according to any one of items 1 to 5, the object detection area of ​​the at least one radar device includes a left object detection area that detects the stationary object on the left side of the moving body, and a right object detection area that detects the stationary object on the right side of the moving body, the angular error calculation unit calculates the angular error for each of the observation angles corresponding to the left object detection area, and calculates the angular error for each of the observation angles corresponding to the right object detection area; an interpolation calculation unit (S250) configured to calculate the angular error of the observation angle between the observation angle corresponding to the left object detection area and the observation angle corresponding to the right object detection area by interpolation using the angular error of the observation angle corresponding to the left object detection area and the angular error of the observation angle corresponding to the right object detection area.

[0114] [Item 7] The angle error estimation device according to any one of items 1 to 6, An angle error estimation device comprising an angle correction unit (S520) configured to correct the azimuth angle detected by the at least one radar device using the angle error.

[0115] [Item 8] An angle error estimation method executed by an angle error estimation device (7) for estimating an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1), comprising: the angle error estimation device acquires object detection information including at least position information indicating the position of an object present near the moving body from the at least one radar device that has an object detection area to the side of the moving body; the angle error estimation device acquires movement trajectory information for identifying a movement trajectory of the moving object; the angle error estimation device detects a stationary object that is a stationary object to the side of the moving body based on the object detection information; the angle error estimation device calculates, for each of the detected plurality of stationary objects, a movement direction indication value that indicates a movement direction of the stationary object as seen from the moving object on the assumption that the moving object is moving straight, for each observation angle at which the at least one radar device observes the stationary object, based on the object detection information and the movement trajectory information; the angle error estimation device classifies the calculated plurality of movement direction indication values ​​into a plurality of observation angles, and calculates, for each observation angle, an average value of the plurality of movement direction indication values ​​classified by the observation angle as a movement direction average value; the angular error estimation device calculates the angular error for each observation angle based on an average trajectory, which is a trajectory calculated based on a plurality of average movement directions calculated for each observation angle, and a reference trajectory set as the trajectory of the stationary object in the absence of the angular error. [Explanation of symbols]

[0116] 3...left rear radar device, 4...right rear radar device, 7...control unit

Claims

1. An angle error estimation device (7) that estimates an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1), a first information acquisition unit (S10) configured to acquire object detection information including at least position information indicating the position of an object present near the moving body from the at least one radar device that includes a side of the moving body as an object detection area; a second information acquisition unit (S20) configured to acquire movement trajectory information for identifying a movement trajectory of the moving object; a stationary object detection unit (S30) configured to detect a stationary object that is an object standing still beside the moving body based on the object detection information; a movement direction calculation unit (S100) configured to calculate, for each of the plurality of stationary objects detected by the stationary object detection unit, a movement direction indication value that indicates a movement direction of the stationary object as seen from the moving object on the assumption that the moving object is moving straight, for each observation angle at which the at least one radar device observes the stationary object, based on the object detection information and the movement trajectory information; an average calculation unit (S210, S710) configured to classify the plurality of movement direction indication values ​​calculated by the movement direction calculation unit into a plurality of observation angles, and to calculate, for each observation angle, an average value of the plurality of movement direction indication values ​​classified by the observation angle as a movement direction average value; an angular error calculation unit (S220 to S240, S720 to S800) configured to calculate the angular error for each observation angle based on an average movement trajectory, which is a movement trajectory calculated based on the plurality of average movement direction values ​​calculated for each observation angle, and a reference movement trajectory set as a movement trajectory of the stationary object when there is no angular error; An angle error estimation device comprising:

2. 2. The angle error estimation device according to claim 1, The angular error estimation device is configured such that, for each of the plurality of observation angles, when the number of the plurality of movement direction indication values ​​classified by the observation angle is equal to or greater than a predetermined validity determination value, the angular error calculation unit (S720 to S800) determines that the movement direction average value of the observation angle is valid, calculates the average movement trajectory, and calculates the angular error corresponding to the observation angle.

3. 2. The angle error estimation device according to claim 1, The angle error estimation device is configured such that, for each of the plurality of observation angles, if the number of the plurality of movement direction indication values ​​classified by the observation angle is equal to or greater than a predetermined validity determination value, the angle error calculation unit (S220 to S240) determines that the movement direction average value of the observation angle is valid and sets a valid continuous section in which the observation angles for which the movement direction average value is valid are continuous, and further, if the section length of the valid continuous section is equal to or greater than the predetermined validity determination value, calculates the average movement trajectory based on the movement direction average value of the plurality of observation angles within the valid continuous section, and calculates the angle error for each of the plurality of observation angles within the valid continuous section.

4. The angle error estimation device according to any one of claims 1 to 3, An angle error estimation device comprising a speed prohibition unit (S80) configured to prohibit the movement direction calculation unit from calculating the movement direction indication value when the traveling speed of the moving body is equal to or less than a preset speed prohibition judgment value.

5. The angle error estimation device according to any one of claims 1 to 3, An angle error estimation device comprising a yaw rate prohibition unit (S90) configured to prohibit the movement direction calculation unit from calculating the movement direction instruction value when the absolute value of the yaw rate of the moving body is equal to or greater than a predetermined yaw rate prohibition judgment value.

6. The angle error estimation device according to any one of claims 1 to 3, the object detection area of ​​the at least one radar device includes a left object detection area that detects the stationary object on the left side of the moving body, and a right object detection area that detects the stationary object on the right side of the moving body, the angular error calculation unit calculates the angular error for each of the observation angles corresponding to the left object detection area, and calculates the angular error for each of the observation angles corresponding to the right object detection area; an interpolation calculation unit (S250) configured to calculate the angular error of the observation angle between the observation angle corresponding to the left object detection area and the observation angle corresponding to the right object detection area by interpolation using the angular error of the observation angle corresponding to the left object detection area and the angular error of the observation angle corresponding to the right object detection area.

7. The angle error estimation device according to any one of claims 1 to 3, An angle error estimation device comprising an angle correction unit (S520) configured to correct the azimuth angle detected by the at least one radar device using the angle error.

8. An angle error estimation method executed by an angle error estimation device (7) for estimating an angle error, which is an error in an azimuth angle detected by at least one radar device (3, 4) mounted on a moving body (VH1), comprising: the angle error estimation device acquires object detection information including at least position information indicating positions of objects present near the moving body from the at least one radar device that has an object detection area to the side of the moving body; the angle error estimation device acquires movement trajectory information for identifying a movement trajectory of the moving object; the angle error estimation device detects a stationary object that is a stationary object to the side of the moving body based on the object detection information; the angle error estimation device calculates, for each of the detected plurality of stationary objects, a movement direction indication value that indicates a movement direction of the stationary object as seen from the moving object on the assumption that the moving object is moving straight, for each observation angle at which the at least one radar device observes the stationary object, based on the object detection information and the movement trajectory information; the angle error estimation device classifies the calculated plurality of movement direction indication values ​​into a plurality of observation angles, and calculates, for each observation angle, an average value of the plurality of movement direction indication values ​​classified by the observation angle as a movement direction average value; the angular error estimation device calculates the angular error for each observation angle based on an average trajectory, which is a trajectory calculated based on a plurality of average movement directions calculated for each observation angle, and a reference trajectory set as the trajectory of the stationary object in the absence of the angular error.

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