Travel speed estimation device

Abstract

A travel speed estimation device (4) is provided with an information acquisition unit (S10), a screening unit (S70-S76), and an estimation unit (S80-S90). The information acquisition unit repeatedly acquires observation point information from a radar device (2) that is mounted on a moving body (VH) and that transmits and receives radar waves, the observation point information including at least an observation point relative speed, which is the relative speed between an observation point at which the radar waves have been reflected and the radar device, and an observation point azimuth, which is the azimuth of the observation point. The screening unit screens observation point information from among the plurality of pieces of observation point information, said observation point information being capable of estimating the travel speed of the moving body close to the true value. The estimation unit estimates the true value of the travel speed on the basis of the observation point relative speed and the observation point azimuth angle of the one or more pieces of observation point information screened by the screening unit.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This international application claims the benefit of priority from Japanese Patent Application No. 2023-14075 filed with the Japan Patent Office on February 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a travel speed estimation device for estimating the travel speed of a mobile object. Background Art

[0004] Patent Document 1 describes a millimeter wave radar device configured to calculate the speed of a vehicle based on the Doppler frequency of a stationary object.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-43139.

[0006] As a result of detailed research, the inventors discovered that estimating the traveling speed of a mobile object equipped with a radar device using radar waves reflected by a stationary object and received by the radar device may result in a decrease in the estimation accuracy of the traveling speed. Summary of the Invention

[0007] The present disclosure improves the estimation accuracy of the traveling speed of a mobile object.

[0008] One aspect of the present disclosure is a traveling speed estimation device including an information acquisition unit, a screening unit, and an estimation unit.

[0009] The information acquisition unit is configured to repeatedly acquire observation point information from a radar device mounted on a mobile body and transmitting and receiving radar waves. The observation point information includes at least the observation point relative velocity, which is the relative velocity between the observation point that reflected the radar wave and the radar device, and the observation point azimuth, which is the azimuth at which the observation point exists.

[0010] The screening unit is configured to screen observation point information from the plurality of observation point information, the observation point information being capable of estimating a traveling speed of the mobile object close to a true value.

[0011] The estimating unit is configured to estimate a true value of the traveling speed based on the observation point relative speed and the observation point azimuth of the one or more observation point information selected by the selecting unit.

[0012] The traveling speed estimation device of the present disclosure configured in this manner can reduce the contribution of observation point information that estimates a traveling speed that deviates from the true value during traveling speed estimation, thereby improving the estimation accuracy of the traveling speed of the mobile object. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a block diagram showing the configuration of a vehicle speed estimation system.

[0014] Figure 2 This is a diagram showing the installation position of the radar device and the object detection area.

[0015] Figure 3 This is a flowchart showing the vehicle speed estimation process according to the first embodiment.

[0016] Figure 4 This is a diagram explaining a method for determining whether or not an object is a stationary object.

[0017] Figure 5 : is a flowchart showing the vehicle speed estimation process according to the second embodiment.

[0018] Figure 6 : is a flowchart showing the vehicle speed estimation process according to the third embodiment.

[0019] Figure 7 It is a diagram showing the vertical azimuth angle.

[0020] Figure 8 : is a flowchart showing the vehicle speed estimation process according to the fourth embodiment.

[0021] Figure 9 It is a diagram showing the horizontal azimuth angle range.

[0022] Figure 10 This is a flowchart showing the vehicle speed estimation process according to the fifth embodiment.

[0023] Figure 11 1 is a flowchart showing the vehicle speed estimation process according to the sixth embodiment.

[0024] Figure 12 1 is a flowchart showing the vehicle speed estimation process according to the seventh embodiment. DETAILED DESCRIPTION

[0025] [First embodiment]

[0026] The following and attached Figure 1 The first embodiment of the present disclosure will be described below.

[0027] The vehicle speed estimation system 1 of this embodiment is mounted on a vehicle. Figure 1 As shown, a radar device 2 , a vehicle speed sensor 3 , and a vehicle speed estimation device 4 are provided.

[0028] like Figure 2 As shown, radar device 2 is installed in front of vehicle VH equipped with vehicle speed estimation system 1. Radar device 2 transmits radar waves toward the front of vehicle VH and receives reflected radar waves to detect objects in object detection area Rf in front of vehicle VH.

[0029] Radar device 2, for example, employs the well-known FMCW method, alternately transmitting radar waves in uplink modulation intervals and downlink modulation intervals at a predetermined modulation cycle, and receiving reflected radar waves. FMCW is an abbreviation for Frequency Modulated Continuous Wave (FMCW). Thus, radar device 2 detects the distance R to the location where the radar wave was reflected (hereinafter referred to as the observation point), the relative velocity Vr of the observation point, the horizontal azimuth angle θ of the observation point, and the vertical azimuth angle of the observation point for each modulation cycle. The horizontal azimuth angle θ is the azimuth angle along the vehicle width direction of the vehicle VH. The radar device 2 will indicate the detected distance R, relative speed Vr, horizontal azimuth θ, and vertical azimuth. The observation point information is output to the vehicle speed estimation device 4.

[0030] The vehicle speed sensor 3 outputs a pulse signal, which generates an edge at every predetermined angle according to the rotation of the drive shaft of the vehicle VH, as a vehicle speed detection signal to the vehicle speed estimation device 4. The vehicle speed estimation device 4 calculates the traveling speed of the vehicle VH (hereinafter referred to as the vehicle speed) based on the vehicle speed detection signal obtained from the vehicle speed sensor 3.

[0031] like Figure 1 As shown, the vehicle speed estimation device 4 is an electronic control unit centered around a microcomputer including a CPU 11, ROM 12, and RAM 13. The various functions of the microcomputer are realized by the CPU 11 executing a program stored on a non-migratable physical recording medium. In this example, the ROM 12 corresponds to the non-migratable physical recording medium storing the program. Furthermore, the execution of the program executes the method corresponding to the program. Alternatively, some or all of the functions performed by the CPU 11 may be implemented in hardware using one or more integrated circuits. The number of microcomputers comprising the vehicle speed estimation device 4 may be one or more.

[0032] The procedure of the vehicle speed estimation process executed by the vehicle speed estimation device 4 will be described. The vehicle speed estimation process is a process that is repeatedly executed during the operation of the vehicle speed estimation device 4 .

[0033] If the vehicle speed estimation process is executed, Figure 3 As shown, the CPU 11 of the vehicle speed estimation device 4 acquires observation point information from the radar device 2 in S10 .

[0034] In S20 , the CPU 11 acquires a vehicle speed detection signal from the vehicle speed sensor 3 .

[0035] In S30, the CPU 11 determines whether the observation point corresponding to the observation point information acquired in S10 is a location where the image is reflected by a stationary object (e.g., a guardrail or a side wall). Figure 4 As shown, when the absolute value of (Vn - Vr / cosθ) is near 0, CPU 11 determines that the observation point is a location where reflection occurs at a stationary object. Vn is the vehicle speed calculated based on the vehicle speed detection signal acquired in S20. Vr is the relative speed of the observation point detected by radar device 2. θ is the horizontal azimuth angle of the observation point detected by radar device 2.

[0036] like Figure 3 As shown, in S40, the CPU 11 determines whether the radar device 2 has detected a stationary object based on the determination result in S30. If no stationary object is detected, the CPU 11 proceeds to S60. On the other hand, if a stationary object is detected, the CPU 11 in S50 stores the observation point information acquired in S10 as stationary object observation point information (hereinafter referred to as stationary observation point information) in the RAM 13 and proceeds to S60.

[0037] When the process proceeds to S60, the CPU 11 determines whether a preset vehicle speed estimation condition is satisfied. The vehicle speed estimation condition in the present embodiment is, for example, that a preset execution cycle has elapsed.

[0038] Here, if the vehicle speed estimation conditions are not met, the CPU 11 terminates the vehicle speed estimation process. On the other hand, if the vehicle speed estimation conditions are met, the CPU 11, at S70, excludes stationary observation point information with a large horizontal azimuth angle θ from the stationary observation point information stored in the RAM 13. Specifically, the CPU 11 determines, for each stationary observation point information stored in the RAM 13, whether the absolute value of the horizontal azimuth angle θ reported in the stationary observation point information is above a pre-set first exclusion threshold. If the absolute value of the horizontal azimuth angle θ is above the first exclusion threshold, the corresponding stationary observation point information is excluded.

[0039] At S80 , the CPU 11 calculates the travel direction component Vt of the relative speed Vr included in each stationary observation point information stored in the RAM 13 and not excluded by the process of S70 . Specifically, the CPU 11 calculates the travel direction component Vt of the relative speed Vr according to Vt=Vr / cosθ.

[0040] In S90, the CPU 11 calculates the median of the one or more travel direction components Vt calculated in S80 and uses the calculated median as the estimated vehicle speed. Alternatively, the CPU 11 may calculate the average of the one or more travel direction components Vt calculated in S80 as the estimated vehicle speed, or may calculate the mode of the one or more travel direction components Vt calculated in S80 as the estimated vehicle speed.

[0041] At S100 , the CPU 11 outputs estimated vehicle speed information indicating the estimated vehicle speed calculated at S90 to an onboard device that utilizes the estimated vehicle speed.

[0042] In S110 , the CPU 11 deletes the stationary observation point information stored in the RAM 13 and ends the vehicle speed estimation process.

[0043] The vehicle speed estimation device 4 configured as described above is configured to repeatedly acquire observation point information including at least the relative speed Vr and the horizontal azimuth angle θ between the observation point where the radar wave is reflected and the radar device 2 from the radar device 2 mounted on the vehicle VH and transmitting and receiving radar waves.

[0044] The vehicle speed estimation device 4 is configured to select observation point information that can estimate the vehicle speed of the vehicle VH close to the true value from a plurality of observation point information.

[0045] The vehicle speed estimation device 4 is configured to estimate the true value of the vehicle speed based on the relative speed Vr and the horizontal azimuth angle θ of the selected one or more observation point information.

[0046] Such a vehicle speed estimation device 4 can reduce the contribution of observation point information that estimates a vehicle speed that deviates from the true value in vehicle speed estimation, and can improve the estimation accuracy of the vehicle speed of the vehicle VH.

[0047] Furthermore, the vehicle speed estimation device 4 is configured to determine whether the observation point is a location where radar waves are reflected by a stationary object, i.e., a stationary observation point. Furthermore, the vehicle speed estimation device 4 selects observation point information determined to be a stationary observation point (i.e., stationary observation point information) that can estimate the vehicle speed of the vehicle VH closer to the true value. Since this vehicle speed estimation device 4 estimates the vehicle speed of the vehicle VH based on the stationary object observation point information, it is possible to further improve the estimation accuracy of the vehicle speed of the vehicle VH.

[0048] Specifically, the vehicle speed estimation device 4 filters the stationary observation point information by excluding stationary observation point information that causes a large error from the true value when estimating the true value (hereinafter referred to as an error factor).

[0049] Furthermore, the vehicle speed estimation device 4 excludes stationary observation point information that is a factor of error (hereinafter referred to as an angle error factor) caused by the azimuth angle at which the observation point is located (hereinafter referred to as the observation point azimuth angle). Specifically, the stationary observation point information that is a factor of angle error is excluded by excluding stationary observation point information that includes a horizontal azimuth angle θ that satisfies a predetermined horizontal azimuth angle exclusion condition indicating that the horizontal azimuth angle θ is large. In this embodiment, the horizontal azimuth angle exclusion condition is that the absolute value of the horizontal azimuth angle θ included in the stationary observation point information is greater than or equal to a predetermined first exclusion threshold.

[0050] Furthermore, the vehicle speed estimation device 4 estimates the true value of the vehicle VH speed by calculating the median of the vehicle speeds calculated based on each of the one or more selected stationary observation point information. This allows the vehicle speed estimation device 4 to estimate the true value using a simple method such as calculating the median.

[0051] In the embodiment described above, the vehicle speed estimation device 4 corresponds to the travel speed estimation device, the vehicle VH corresponds to the mobile object, the relative speed Vr corresponds to the observation point relative speed, and the horizontal azimuth angle θ corresponds to the observation point azimuth.

[0052] In addition, S10 corresponds to the processing of the information acquisition unit, S70 corresponds to the processing of the screening unit, S80 and S90 correspond to the processing of the estimation unit, and S30 corresponds to the processing of the stationary object determination unit.

[0053] [Second embodiment]

[0054] The following and attached Figure 1 The second embodiment of the present disclosure will be described. In the second embodiment, the parts that are different from the first embodiment will be described. The same reference numerals are attached to the same components.

[0055] The vehicle speed estimation system 1 of the second embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0056] like Figure 5 As shown, the vehicle speed estimation process of the second embodiment differs from the first embodiment in that the process of S71 is executed instead of the process of S70 .

[0057] That is, when the vehicle speed estimation condition is satisfied in S60 , the CPU 11 excludes the stationary observation point information so that the number of stationary observation point information is the same on the left and right in S71 , and then moves to S80 .

[0058] Specifically, the CPU 11 determines whether each stationary observation point information stored in the RAM 13 is stationary observation point information of a stationary object located on the left side of the vehicle VH or on the right side of the vehicle VH based on the horizontal azimuth θ included in the stationary observation point information.

[0059] Next, the CPU 11 calculates the number of stationary observation point information of stationary objects located on the left side of the vehicle VH (hereinafter referred to as the left side observation point number) and the number of stationary observation point information of stationary objects located on the right side of the vehicle VH (hereinafter referred to as the right side observation point number).

[0060] The CPU 11 then excludes stationary observation point information in such a way that the number of observation points on the left and right sides matches. For example, if the number of observation points on the left is 20 and the number of observation points on the right is 15, the CPU 11 excludes stationary observation point information for five stationary objects located on the left side of the vehicle VH. Furthermore, the CPU 11 can exclude the required number of stationary observation point information randomly, in the order of relative velocity Vr from slowest to fastest, or in the order of relative velocity Vr from fast to slow. Furthermore, the CPU 11 can exclude stationary observation point information in the order of Vr / cosθ (i.e., the travel direction component Vt of the relative velocity Vr) from fast to slow, or in the order of Vr / cosθ from slow to fast.

[0061] The vehicle speed estimation device 4 configured in this manner excludes stationary observation point information that contributes to angular error by excluding stationary observation point information such that the number of stationary observation point information for stationary observation points located on the left side of the vehicle VH (i.e., the number of left observation points) matches the number of stationary observation point information for stationary observation points located on the right side of the vehicle VH (i.e., the number of right observation points). This eliminates stationary observation point information that contributes to angular error. Consequently, the vehicle speed estimation device 4 can reduce the contribution of stationary observation point information that deviates from the true value of the estimated vehicle speed, thereby improving the accuracy of vehicle speed estimation.

[0062] In the embodiment described above, S71 corresponds to the processing as the screening unit.

[0063] [Third embodiment]

[0064] The following and attached Figure 1 The third embodiment of the present disclosure will be described. In the third embodiment, the parts that differ from the first embodiment will be described. Identical components are denoted by the same reference numerals.

[0065] The vehicle speed estimation system 1 of the third embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0066] like Figure 6As shown, the vehicle speed estimation process of the third embodiment is different from the first embodiment in that the process of S72 is executed instead of the process of S70 .

[0067] That is, if the vehicle speed estimation condition is satisfied in S60, the CPU 11 excludes the stationary observation point information of the stationary object located above or below the vehicle VH in S72 and moves to S80. Figure 7 As shown, the CPU 11 determines the vertical azimuth angle included in each stationary observation point information stored in the RAM 13. Is the absolute value of the vertical azimuth angle above the preset second exclusion threshold? When the absolute value of is greater than the second exclusion threshold, the corresponding stationary observation point information is excluded.

[0068] The vehicle speed estimation device 4 configured in this manner excludes stationary observation point information located above or below the vehicle VH. Specifically, the vehicle speed estimation device 4 excludes stationary observation point information including information that satisfies the vertical azimuth angle. The vertical azimuth angle of the pre-set vertical azimuth angle in this case is larger than the vertical azimuth angle of the pre-set vertical azimuth angle. The vertical azimuth angle exclusion condition of this embodiment is the vertical azimuth angle The absolute value of is above a preset second exclusion threshold.

[0069] As a result, the vehicle speed estimation device 4 can reduce the contribution of the stationary observation point information that estimates a vehicle speed that deviates from the true value, and can improve the estimation accuracy of the vehicle speed of the vehicle VH.

[0070] In the embodiment described above, S72 corresponds to the processing as the screening unit.

[0071] [Fourth embodiment]

[0072] The following and attached Figure 1 The fourth embodiment of the present disclosure will be described. In the fourth embodiment, the parts that differ from the first embodiment will be described. The same reference numerals are assigned to the same components.

[0073] The vehicle speed estimation system 1 of the fourth embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0074] like Figure 8 As shown, the vehicle speed estimation process of the fourth embodiment differs from the first embodiment in that the process of S73 is executed instead of the process of S70 .

[0075] Specifically, if the vehicle speed estimation condition is satisfied in S60 , the CPU 11 excludes stationary observation point information other than the stationary object with the fastest relative speed within each azimuth range in S73 and proceeds to S80 .

[0076] Specifically, if Figure 9 As shown, the CPU 11 determines, for each stationary observation point information stored in the RAM 13 , which of the plurality of horizontal azimuth angle ranges R1 , R2 , . . . , R19 , and R20 the stationary observation point information belongs to based on the horizontal azimuth angle θ included in the stationary observation point information.

[0077] A plurality of horizontal azimuth angle ranges R1, R2, ..., R19, and R20 are formed by equally dividing the range of the horizontal azimuth angle θ from -90 to +90 degrees into twenty ranges.

[0078] For example, the horizontal azimuth angle range R1 is -90° to -81°. The horizontal azimuth angle range R2 is -81° to -72°. The horizontal azimuth angle range R10 is -9° to 0°. The horizontal azimuth angle range R11 is 0° to +9°. The horizontal azimuth angle range R20 is +81° to +90°.

[0079] The CPU 11 extracts the stationary observation point information having the maximum relative speed Vr from the stationary observation point information belonging to the horizontal azimuth angle ranges R1 to R20 for each of the plurality of horizontal azimuth angle ranges R1 to R20, and excludes the stationary observation point information other than the extracted stationary observation point information. Figure 9 In the figure, black circles indicate the stationary observation point information with the maximum relative velocity Vr within each horizontal azimuth angle range. Hollow circles indicate stationary observation point information that is excluded because the relative velocity Vr is not the maximum within each horizontal azimuth angle range. For example, point P1 within horizontal azimuth angle range R8 indicates the stationary observation point information with the maximum relative velocity Vr within horizontal azimuth angle range R8, while point P2 within horizontal azimuth angle range R8 indicates the stationary observation point information with the maximum relative velocity Vr within horizontal azimuth angle range R8, and is excluded because the relative velocity Vr is not the maximum within horizontal azimuth angle range R8.

[0080] The vehicle speed estimation device 4 configured in this manner classifies each of the plurality of stationary observation point information into one of a plurality of horizontal azimuth angle ranges R1 to R20 based on the horizontal azimuth angle θ included in the stationary observation point information. Furthermore, for each of the plurality of horizontal azimuth angle ranges R1 to R20, the vehicle speed estimation device 4 excludes stationary observation point information other than the stationary observation point information having the highest relative speed Vr from one or more of the stationary observation point information within the horizontal azimuth angle ranges R1 to R20, thereby excluding stationary observation point information located above or below the vehicle VH.

[0081] As a result, the vehicle speed estimation device 4 can reduce the contribution of the stationary observation point information that estimates a vehicle speed that deviates from the true value, and can improve the estimation accuracy of the vehicle speed of the vehicle VH.

[0082] In the embodiment described above, S73 corresponds to the processing as the screening unit.

[0083] [Fifth embodiment]

[0084] The following and attached Figure 1 The fifth embodiment of the present disclosure will be described. In the fifth embodiment, the parts that are different from the first embodiment will be described. The same reference numerals are attached to the same components.

[0085] The vehicle speed estimation system 1 of the fifth embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0086] like Figure 10 As shown, the vehicle speed estimation process of the fifth embodiment differs from the first embodiment in that the process of S74 is executed instead of the process of S70 .

[0087] Specifically, if the vehicle speed estimation conditions are met in S60, the CPU 11 excludes stationary observation point information for stationary objects that are relatively close to the vehicle VH in S74 and proceeds to S80. Specifically, the CPU 11 determines whether the distance R included in each stationary observation point information stored in the RAM 13 is below a predetermined fourth exclusion threshold. If the distance R is below the fourth exclusion threshold, the corresponding stationary observation point information is excluded.

[0088] The vehicle speed estimation device 4 configured in this manner excludes stationary observation point information located above or below the vehicle VH by excluding stationary observation point information including a distance R that satisfies a preset distance exclusion condition indicating that the distance R is short.

[0089] As a result, the vehicle speed estimation device 4 can reduce the contribution of the stationary observation point information that estimates a vehicle speed that deviates from the true value, and can improve the estimation accuracy of the vehicle speed of the vehicle VH.

[0090] In the embodiment described above, S74 corresponds to the processing of the screening unit, and the distance R corresponds to the observation point distance.

[0091] [Sixth embodiment]

[0092] The following and attached Figure 1 The sixth embodiment of the present disclosure will be described. In the sixth embodiment, the parts that differ from the first embodiment will be described. Identical components are denoted by the same reference numerals.

[0093] The vehicle speed estimation system 1 of the sixth embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0094] like Figure 11 As shown, the vehicle speed estimation process of the sixth embodiment differs from the first embodiment in that the process of S75 is executed instead of the process of S70 .

[0095] Specifically, if the vehicle speed estimation conditions are met in S60, the CPU 11, in S75, excludes stationary observation point information for stationary objects whose travel direction component Vt of the relative speed Vr is not near the vehicle speed Vn calculated from the vehicle speed detection signal and proceeds to S80. Specifically, the CPU 11 determines whether the travel direction component Vt of the relative speed Vr contained in each stationary observation point information stored in RAM 13 is outside a pre-set exclusion range. If the travel direction component Vt is outside the exclusion range, the corresponding stationary observation point information is excluded. The exclusion range is a range with a lower limit of (Vn - ε) and an upper limit of (Vn + ε). ε is a constant pre-set to ensure that the exclusion range is near the vehicle speed Vn. Specifically, the CPU 11 excludes the corresponding stationary observation point information if Vt < (Vn - ε) or Vt > (Vn + ε).

[0096] The vehicle speed estimation device 4 configured in this manner excludes stationary observation point information that includes a relative speed Vr that satisfies a predetermined speed exclusion condition. This speed exclusion condition indicates that the magnitude of the vehicle VH's traveling direction component of the relative speed Vr (i.e., the traveling direction component Vt of the relative speed Vr) is not near the travel speed (i.e., the vehicle speed Vn) calculated based on the rotational speed of the wheels of the vehicle VH. Furthermore, the vehicle speed estimation device 4 calculates the traveling direction component Vt of the relative speed Vr for each of the plurality of stationary observation point information based on the relative speed Vr and the horizontal azimuth angle θ included in the stationary observation point information. The speed exclusion condition in this embodiment is that the traveling direction component Vt of the relative speed Vr is outside a predetermined exclusion range.

[0097] Such a vehicle speed estimation device 4 can reduce the contribution of the stationary observation point information that estimates a vehicle speed that deviates from the true value in vehicle speed estimation, thereby improving the estimation accuracy of the vehicle speed of the vehicle VH.

[0098] In the embodiment described above, S75 corresponds to the processing as the screening unit.

[0099] [Seventh embodiment]

[0100] The following and attached Figure 1 The seventh embodiment of the present disclosure will be described. In the seventh embodiment, the parts that differ from the first embodiment will be described. Identical components are denoted by the same reference numerals.

[0101] The vehicle speed estimation system 1 of the seventh embodiment differs from the first embodiment in that the vehicle speed estimation process is changed.

[0102] like Figure 12 As shown, the vehicle speed estimation process of the seventh embodiment differs from the first embodiment in that the process of S76 is executed instead of the process of S70 , the process of S86 is executed instead of the process of S80 , and the process of S76 is executed after the process of S86 is executed.

[0103] Specifically, when the vehicle speed estimation condition is satisfied in S60 , the CPU 11 calculates the traveling direction component Vt of the relative speed Vr included in the stationary observation point information for each stationary observation point information stored in the RAM 13 in S86 .

[0104] After the processing of S86 is completed, the CPU 11 excludes stationary observation point information whose travel direction component Vt is not near the vehicle speed Vn calculated based on the vehicle speed detection signal in S76 and proceeds to S90. Specifically, similar to S75, the CPU 11 determines for each stationary observation point information stored in the RAM 13 whether the travel direction component Vt of the relative speed Vr included in the stationary observation point information is outside a pre-set exclusion range. If the travel direction component Vt is outside the exclusion range, the corresponding stationary observation point information is excluded.

[0105] The vehicle speed estimation device 4 configured in this manner excludes stationary observation point information that includes a relative speed Vr that satisfies a predetermined speed exclusion condition. This speed exclusion condition indicates that the magnitude of the vehicle VH's traveling direction component of the relative speed Vr (i.e., the traveling direction component Vt of the relative speed Vr) is not near the travel speed (i.e., the vehicle speed Vn) calculated based on the rotational speed of the wheels of the vehicle VH. Furthermore, the vehicle speed estimation device 4 calculates the traveling direction component Vt of the relative speed Vr for each of the plurality of stationary observation point information based on the relative speed Vr and the horizontal azimuth angle θ included in the stationary observation point information. The speed exclusion condition in this embodiment is that the traveling direction component Vt of the relative speed Vr is outside a predetermined exclusion range.

[0106] Such a vehicle speed estimation device 4 can reduce the contribution of the stationary observation point information that estimates a vehicle speed that deviates from the true value in vehicle speed estimation, thereby improving the estimation accuracy of the vehicle speed of the vehicle VH.

[0107] In the embodiment described above, S76 corresponds to the processing as the screening unit.

[0108] As mentioned above, although one embodiment of the present disclosure has been described, the present disclosure is not limited to the above embodiment, and can be implemented with various modifications.

[0109] [Variation 1]

[0110] For example, in the above embodiment, the movable body is shown as a vehicle VH, but the movable body is not limited thereto, and may be, for example, a two-wheeled motorcycle.

[0111] [Variation 2]

[0112] In the above embodiment, the radar device 2 employs the FMCW method. However, the radar method of the radar device 2 may be any method capable of detecting relative velocity, and may employ, for example, a dual-frequency CW method or an FCM method. FCM is an abbreviation for Fast-Chirp Modulation.

[0113] [Variation 3]

[0114] In the first, second, third, fourth, fifth, sixth, and seventh embodiments described above, the processes of S70, S71, S72, S73, S74, S75, and S76 are respectively executed. However, the processes of S70 to S76 may be combined to exclude observation point information. For example, the processes of S70, S72, and S75 may be combined, the processes of S71 and S73 may be combined, or the processes of S74 and S75 may be combined.

[0115] [Variation 4]

[0116] In the fourth embodiment described above, a method of excluding stationary observation point information other than the stationary object with the fastest relative speed within each azimuth range in S73 is shown, but stationary observation point information other than the stationary object with the shortest distance within each azimuth range may also be excluded in S73.

[0117] [Variation 5]

[0118] In the above embodiment, a method is shown in which, in S30, when the absolute value of (Vn-Vr / cosθ) is near 0, it is determined that the observation point is a location where reflection has occurred on a stationary object. However, the method for determining whether the observation point is a location where reflection has occurred on a stationary object is not limited to this. For example, by sequentially recording the driving speed of the vehicle VH, the direction of travel of the vehicle VH, and the position of the observation point observed by the radar device 2, it is possible to calculate the time change of the position of the observation point on a two-dimensional orthogonal coordinate system with the position of the vehicle VH as the origin at a certain moment. When the position of the observation point on the two-dimensional orthogonal coordinate system does not change over time, it can be determined that the observation point is a location where reflection has occurred on a stationary object. In addition, instead of using the driving speed of the vehicle VH and the direction of travel of the vehicle VH, the position of the vehicle VH can be calculated based on GPS information. GPS is an abbreviation of Global Positioning System.

[0119] Furthermore, if the observation point detected by the radar device 2 is a location where reflection occurs at a stationary object (i.e., a stationary observation point), the closer the vehicle VH approaches the stationary observation point and the larger the horizontal azimuth angle θ of the stationary observation point, the smaller the relative velocity Vr of the observation point detected by the radar device 2. Therefore, the relative velocity Vr and horizontal azimuth angle θ of the same observation point can be sequentially recorded and plotted in a two-dimensional orthogonal coordinate system with the horizontal azimuth angle θ on the horizontal axis and the relative velocity Vr on the vertical axis. If the plotted point cluster is distributed near a stationary object curve representing the relationship between the horizontal azimuth angle θ and the relative velocity Vr, assuming the observation point is stationary, it can be determined that the observation point is a location where reflection occurs at a stationary object.

[0120] The vehicle speed estimation device 4 and its method described in the present disclosure may also be implemented by a dedicated computer comprising a processor and memory programmed to execute one or more functions embodied by a computer program. Alternatively, the vehicle speed estimation device 4 and its method described in the present disclosure may also be implemented by a dedicated computer comprising a processor comprising one or more dedicated hardware logic circuits. Alternatively, the vehicle speed estimation device 4 and its method described in the present disclosure may also be implemented by one or more dedicated computers comprising a processor and memory programmed to execute one or more functions, and a processor comprising one or more hardware logic circuits. In addition, a computer program may be stored as instructions executed by a computer on a non-portable tangible recording medium that can be read by a computer. The method for implementing the functions of the various components included in the vehicle speed estimation device 4 does not necessarily need to include software; all of its functions may be implemented using one or more hardware components.

[0121] It is also possible to implement multiple functions of a component in the above-mentioned embodiment by multiple components, or to implement a single function of a component by multiple components. In addition, it is also possible to implement multiple functions of multiple components by one component, or to implement a single function implemented by multiple components by one component. In addition, it is also possible to omit part of the components of the above-mentioned embodiment. In addition, it is also possible to add or replace at least part of the components of the above-mentioned embodiment with the components of another above-mentioned embodiment.

[0122] In addition to the above-mentioned vehicle speed estimation device 4, the present disclosure can also be implemented in various forms, such as a system that uses the vehicle speed estimation device 4 as a component, a program for causing a computer to function as the vehicle speed estimation device 4, a non-migratable physical recording medium such as a semiconductor memory that records the program, and a vehicle speed estimation method.

[0123] [Technical Ideas Disclosed in This Specification]

[0124] [Item 1] A driving speed estimation device (4), comprising:

[0125] An information acquisition unit (S10) is configured to repeatedly acquire observation point information from a radar device (2) mounted on a mobile body (VH) and transmitting and receiving radar waves, the observation point information including at least an observation point relative speed, which is a relative speed between the observation point reflecting the radar wave and the radar device, and an observation point azimuth, which is an azimuth at which the observation point exists;

[0126] a screening unit (S70 to S76) configured to screen the observation point information that can estimate the traveling speed of the mobile body close to the true value from the plurality of observation point information; and

[0127] The estimating unit (S80-S90) is configured to estimate the true value of the traveling speed based on the observation point relative speed and the observation point azimuth of the one or more observation point information selected by the selecting unit.

[0128] [Project 2]

[0129] According to the driving speed estimation device described in item 1,

[0130] The stationary object determination unit (S30) is configured to determine whether the observation point is a stationary observation point at which the radar wave is reflected by a stationary object.

[0131] The screening unit screens the observation point information that can estimate the traveling speed of the mobile object close to the true value from the observation point information determined by the stationary object determination unit as the stationary observation point.

[0132] [Item 3]

[0133] According to the driving speed estimation device described in item 1 or item 2,

[0134] The screening unit screens the observation point information by excluding the observation point information that becomes a factor causing an error from the true value to increase when the estimation unit estimates the true value, that is, an error factor.

[0135] [Item 4]

[0136] According to the driving speed estimation device described in item 3,

[0137] The screening unit (S70, S71) excludes the observation point information that is the error factor caused by the azimuth angle of the observation point, that is, the angle error factor.

[0138] [Item 5]

[0139] According to the driving speed estimation device described in item 4,

[0140] The screening unit (S71) excludes the observation point information that is a cause of the angle error by excluding the observation point information in such a manner that the number of the observation point information of the observation points located on the left side of the moving body is consistent with the number of the observation point information of the observation points located on the right side of the moving body.

[0141] [Item 6]

[0142] According to the driving speed estimation device described in item 4,

[0143] The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth.

[0144] The screening unit (S70) excludes the observation point information that is a factor of the angle error by excluding the observation point information including the horizontal azimuth angle that satisfies a preset horizontal azimuth angle exclusion condition indicating that the horizontal azimuth angle is large.

[0145] [Item 7]

[0146] The traveling speed estimating device according to any one of items 1 to 6,

[0147] The filtering unit (S72, S73, S74) excludes the observation point information of the observation point located above or below the moving object.

[0148] [Item 8]

[0149] According to the driving speed estimation device described in item 7,

[0150] The observation point azimuth includes the azimuth in the vertical direction relative to the moving object, that is, the vertical azimuth.

[0151] The screening unit (S72) excludes the observation point information of the observation points located above or below the moving object by excluding the observation point information including the vertical azimuth angle that satisfies a preset vertical azimuth angle exclusion condition indicating that the vertical azimuth angle is large.

[0152] [Item 9]

[0153] According to the driving speed estimation device described in item 7,

[0154] The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth.

[0155] The screening unit (S73) classifies the plurality of observation point information into any one of a plurality of horizontal azimuth ranges based on the observation point azimuths contained in the observation point information, and excludes, for each of the plurality of horizontal azimuth ranges, the observation point information having the largest relative speed of the observation point, or the observation point information having the smallest distance between the observation point and the radar device, i.e., the smallest observation point distance, except for the observation point information of the observation point located above or below the moving body, from one or more of the observation point information belonging to the horizontal azimuth range.

[0156] [Item 10]

[0157] According to the driving speed estimation device described in item 7,

[0158] The observation point information includes the distance between the observation point and the radar device, that is, the observation point distance.

[0159] The screening unit (S74) excludes the observation point information of the observation points located above or below the moving object by excluding the observation point information including the observation point distance that satisfies a preset distance exclusion condition indicating that the observation point distance is short.

[0160] [Item 11]

[0161] The traveling speed estimating device according to any one of items 1 to 10,

[0162] The above-mentioned filtering unit (S75, S76) excludes the above-mentioned observation point information including the above-mentioned observation point relative speed that satisfies a predetermined speed exclusion condition, wherein the speed exclusion condition indicates that the magnitude of the traveling direction component of the above-mentioned moving body in the above-mentioned observation point relative speed is not near the above-mentioned driving speed calculated based on the rotation speed of the wheels of the above-mentioned moving body.

[0163] [Item 12]

[0164] According to the driving speed estimation device described in item 11,

[0165] The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth.

[0166] The screening unit calculates the traveling direction component of the observation point relative speed for each of the plurality of observation point information based on the observation point relative speed and the horizontal azimuth angle included in the observation point information.

[0167] [Item 13]

[0168] The traveling speed estimation device according to any one of items 1 to 12,

[0169] The estimating unit estimates the true value of the traveling speed by calculating a median, an average, or a mode of one or more traveling speeds calculated based on each of the one or more observation point information filtered by the filtering unit.

Claims

1. A driving speed estimation device (4), wherein: have: An information acquisition unit (S10) is configured to repeatedly acquire observation point information from a radar device (2) mounted on a mobile body (VH) and transmitting and receiving radar waves, the observation point information including at least an observation point relative speed, which is a relative speed between the observation point reflecting the radar wave and the radar device, and an observation point azimuth, which is an azimuth at which the observation point exists; a screening unit (S70 to S76) configured to screen the observation point information from the plurality of observation point information for estimating the travel speed of the mobile object close to the true value; as well as The estimating unit (S80-S90) is configured to estimate the true value of the traveling speed based on the observation point relative speed and the observation point azimuth of the one or more observation point information selected by the selecting unit.

2. The traveling speed estimation device according to claim 1, wherein: Also features: The stationary object determination unit (S30) is configured to determine whether the observation point is a stationary observation point at which the radar wave is reflected by a stationary object. The screening unit screens the observation point information that can estimate the traveling speed of the mobile object close to the true value from the observation point information determined by the stationary object determination unit as the stationary observation point.

3. The driving speed estimation device according to claim 1 or claim 2, wherein: The screening unit screens the observation point information by excluding the observation point information that becomes a factor causing an error from the true value to increase when the estimation unit estimates the true value, that is, an error factor.

4. The traveling speed estimation device according to claim 3, wherein: The screening unit (S70, S71) excludes the observation point information that is the error factor caused by the azimuth angle of the observation point, that is, the angle error factor.

5. The traveling speed estimation device according to claim 4, wherein: The screening unit (S71) excludes the observation point information that is a cause of the angle error by excluding the observation point information in such a manner that the number of the observation point information of the observation points located on the left side of the moving body is consistent with the number of the observation point information of the observation points located on the right side of the moving body.

6. The traveling speed estimation device according to claim 4, wherein: The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth. The screening unit (S70) excludes the observation point information that is a factor of the angle error by excluding the observation point information including the horizontal azimuth angle that satisfies a preset horizontal azimuth angle exclusion condition indicating that the horizontal azimuth angle is large.

7. The driving speed estimation device according to claim 1 or claim 2, wherein: The filtering unit (S72, S73, S74) excludes the observation point information of the observation point located above or below the moving object.

8. The traveling speed estimation device according to claim 7, wherein: The observation point azimuth includes the azimuth in the vertical direction relative to the moving object, that is, the vertical azimuth. The screening unit (S72) excludes the observation point information of the observation points located above or below the moving object by excluding the observation point information including the vertical azimuth angle that satisfies a preset vertical azimuth angle exclusion condition indicating that the vertical azimuth angle is large.

9. The traveling speed estimation device according to claim 7, wherein: The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth. The screening unit (S73) classifies the plurality of observation point information into any one of a plurality of horizontal azimuth ranges based on the observation point azimuths included in the observation point information, and excludes, from one or more of the observation point information belonging to the horizontal azimuth ranges, the observation point information having the largest relative speed of the observation point, or the observation point information having the smallest distance between the observation point and the radar device, i.e., the smallest observation point distance, thereby excluding the observation point information of the observation point located above or below the moving body.

10. The traveling speed estimation device according to claim 7, wherein: The observation point information includes the distance between the observation point and the radar device, that is, the observation point distance. The screening unit (S74) excludes the observation point information of the observation points located above or below the moving object by excluding the observation point information including the observation point distance that satisfies a preset distance exclusion condition indicating that the observation point distance is short.

11. The driving speed estimation device according to claim 1 or claim 2, wherein: The above-mentioned filtering unit (S75, S76) excludes the above-mentioned observation point information including the above-mentioned observation point relative speed that satisfies a predetermined speed exclusion condition, wherein the speed exclusion condition indicates that the magnitude of the traveling direction component of the above-mentioned moving body in the above-mentioned observation point relative speed is not near the above-mentioned driving speed calculated based on the rotation speed of the wheels of the above-mentioned moving body.

12. The traveling speed estimation device according to claim 11, wherein: The observation point azimuth includes the azimuth along the horizontal direction relative to the moving object, that is, the horizontal azimuth. The screening unit calculates the traveling direction component of the observation point relative speed for each of the plurality of observation point information based on the observation point relative speed and the horizontal azimuth angle included in the observation point information.

13. The driving speed estimation device according to claim 1 or claim 2, wherein: The estimating unit estimates the true value of the traveling speed by calculating a median, an average, or a mode of one or more traveling speeds calculated based on each of the one or more observation point information filtered by the filtering unit.

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