Speed ​​measuring device and speed measuring method

Abstract

In order to suppress the influence of the installation height and measure the speed of the moving object with high accuracy, the speed measuring device of the present invention includes: a radar unit that detects the moving object moving along the road and outputs a detection value r of the distance m , the detected value of the azimuth angle θ m And the speed detection value V m , wherein the speed is a Doppler speed; a storage unit storing a θ-rV curve (characteristic curve) representing the relationship between the rV value (characteristic quantity) given by the product of the distance and the speed at a specified speed and the azimuth angle θ; and a processor, which detects the value r based on the distance m , the detected value of the azimuth angle θ m And the speed detection value V m To estimate the speed of the moving object, the processor converts the detected value r of the distance m The speed detection value V m Multiply to calculate the measured value of rV (r m ×V m ), and based on the θ-rV curve, the measured value of rV value and the detected value of azimuth angle θ m To get the estimated speed.

Description

Technical Field

[0001] The present disclosure relates to a speed measuring device and a speed measuring method for measuring the speed of a moving object moving on a road using a radar. Background Art

[0002] A technology for measuring the speed of vehicles traveling on the road in order to supervise speed violations has become popular. As a technology for measuring the speed of vehicles on the road, the following technology is known in the past: using radar to irradiate radio waves to a moving object on the road and capture the reflected waves, and processing the signal (Doppler signal) included in the reflected waves to measure the speed of the moving object (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6309328 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In addition, it is expected that radar devices that detect moving objects (vehicles, people, animals, etc.) on the road will be used as so-called infrastructure radars in the future in vehicle automatic driving systems, etc. In this case, the radar device is installed on the pillars of traffic lights installed at intersections, the pillars of street lights installed on the side of the road, etc. Therefore, the installation height of the radar device increases.

[0008] However, in the above-mentioned prior art, the Doppler velocity is directly obtained as the velocity of the moving object. When the radar device is installed at a high place, the error of the Doppler velocity relative to the actual velocity becomes large. In particular, although the influence of the installation height of the radar is small when a large device with a low frequency of radio waves is used to detect a moving object located far away, the influence of the installation height of the radar becomes large in response to the desire to achieve miniaturization of the device.

[0009] Therefore, a main object of the present disclosure is to provide a speed measuring device and a speed measuring method that can suppress the influence of the installation height and measure the speed of a moving object with high accuracy.

[0010] Solutions for solving problems

[0011] The speed measuring device disclosed in the present invention is a speed measuring device that is arranged around a road and measures the speed of a moving body moving along the road, and is configured to include: a radar unit that detects the moving body on the road and outputs a detection value of a distance, a detection value of an azimuth, and a detection value of a speed, wherein the speed is a Doppler speed; a storage unit that stores characteristic information that indicates a relationship between a characteristic quantity given by the product of the distance and the speed at a specified speed and the azimuth; and a processor that estimates the speed of the moving body based on the characteristic information, the detection value of the azimuth, and the measurement value of the characteristic quantity obtained by multiplying the detection value of the distance by the detection value of the speed.

[0012] In addition, the speed measurement method disclosed in the present invention is a speed measurement method that enables an information processing device to perform processing for measuring the speed of a moving body moving along a road, and the speed measurement method is configured such that a processor of the information processing device performs the following processing: obtaining a detection value of a distance, a detection value of an azimuth angle, and a detection value of a speed from a radar unit for detecting a moving body on a road, wherein the speed is a Doppler speed; multiplying the detection value of the distance by the detection value of the speed to calculate a measurement value of a characteristic quantity; and obtaining an estimation result of the speed based on the measurement value of the characteristic quantity, the detection value of the azimuth angle, and characteristic information indicating the relationship between the azimuth angle and the characteristic quantity at a specified speed.

[0013] Effects of the Invention

[0014] According to the present disclosure, since the characteristic quantity given by the product of distance and speed does not depend on the positional relationship between the radar and the moving body in the vertical direction, by estimating the speed of the moving body based on the characteristic quantity, the speed estimation can be performed in a manner that does not depend on the height of the moving body. Thus, the influence of the installation height can be suppressed and the speed of the moving body can be measured with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side view showing a state of speed measurement by the speed measurement device 1 according to the first embodiment.

[0016] Figure 2 It is a side view showing a state of speed measurement by the speed measurement device 1 according to the first embodiment.

[0017] Figure 3 It is a plan view schematically showing the processing performed by the velocity measurement device 1 according to the first embodiment.

[0018] Figure 4 It is a plan view schematically showing the processing performed by the velocity measurement device 1 according to the first embodiment.

[0019] Figure 5 It is an explanatory diagram showing an outline of the processing performed by the velocity measurement device 1 according to the first embodiment.

[0020] Figure 6 It is an explanatory diagram showing an outline of the processing performed by the velocity measurement device 1 according to the first embodiment.

[0021] Figure 7 It is a block diagram showing a schematic configuration of a speed measurement device 1 according to the first embodiment.

[0022] Figure 8 This is a flowchart showing the procedure of processing performed by the speed measurement device 1 according to the first embodiment.

[0023] Fig. 9 It is an explanatory diagram showing an outline of the processing performed by the velocity measurement device 1 according to the second embodiment.

[0024] Fig.10 It is a block diagram showing a schematic configuration of a velocity measurement device 1 according to the second embodiment.

[0025] Fig.11 1 is a flowchart showing the procedure of processing performed by the speed measurement device 1 according to the second embodiment.

[0026] Fig.12 It is an explanatory diagram showing characteristic information according to the third embodiment.

[0027] Fig.13 It is a block diagram showing a schematic configuration of a velocity measurement device 1 according to the third embodiment.

[0028] Fig.14 : is a flowchart showing the procedure of processing performed by the speed measurement device 1 according to the third embodiment. DETAILED DESCRIPTION

[0029] The first invention completed to solve the above-mentioned problem is a speed measuring device that is arranged around a road and measures the speed of a moving body moving along the road, the speed measuring device being configured to include: a radar unit that detects the moving body on the road and outputs a detection value of a distance, a detection value of an azimuth, and a detection value of a speed, wherein the speed is a Doppler speed; a storage unit that stores characteristic information that represents a relationship between a characteristic quantity given by the product of the distance and the speed at a specified speed and the azimuth; and a processor that estimates the speed of the moving body based on the characteristic information, the detection value of the azimuth, and the measurement value of the characteristic quantity obtained by multiplying the detection value of the distance by the detection value of the speed.

[0030] Thus, since the characteristic quantity given by the product of the distance and the speed does not depend on the vertical positional relationship between the radar and the moving object, by estimating the speed of the moving object based on the characteristic quantity, the speed can be estimated in a manner that does not depend on the height of the moving object. Thus, the influence of the installation height can be suppressed and the speed of the moving object can be measured with high accuracy.

[0031] In the second invention, the radar unit is installed at a height at which an elevation angle when the moving body is viewed from the radar unit changes beyond an allowable limit due to a variation in the height of the virtual moving body.

[0032] This makes it possible to ensure the measurement accuracy of the velocity when the error of the Doppler velocity becomes significant due to the high position of the radar unit.

[0033] Furthermore, a third invention is configured such that the processor acquires an estimated value of speed as the estimation result of the speed based on the characteristic information at each of a plurality of speeds.

[0034] This makes it possible to obtain a highly accurate estimated value of the speed.

[0035] In addition, the fourth invention is configured such that the processor obtains the position of a measurement point on a plane with the azimuth and the characteristic quantity as coordinate axes based on the detected value of the distance, the detected value of the azimuth, and the detected value of the speed, determines two characteristic curves closest to the measurement point among a plurality of characteristic curves corresponding to the characteristic information, and obtains an estimated value of the speed by an interpolation method based on the positional relationship between the characteristic curve and the measurement point.

[0036] This makes it possible to acquire a highly accurate estimated value of the speed without setting a large amount of characteristic information (characteristic curve) for each speed at fine intervals.

[0037] In addition, in a fifth aspect of the present invention, the processor performs statistical processing on a plurality of estimated values ​​of the speed acquired by executing the detection processing of the radar unit a plurality of times, thereby acquiring a final estimated value of the speed.

[0038] This can further improve the accuracy of the final estimated value of the speed. Note that the statistical processing is, for example, averaging or the like.

[0039] In addition, in the sixth aspect of the present invention, the processor is configured to acquire, as the estimation result of the speed, a determination result as to whether the speed exceeds the speed limit, based on the characteristic information at the speed limit.

[0040] This makes it possible to obtain a high-precision speed determination result.

[0041] In addition, the seventh invention is configured such that the processor integrates a plurality of speed determination results acquired by executing the detection process of the radar unit a plurality of times, and acquires a final speed determination result.

[0042] This can further improve the accuracy of the final speed determination result.

[0043] In addition, in an eighth aspect of the present invention, the processor determines the type of the moving object detected by the radar unit, and acquires the estimation result of the speed based on the characteristic information corresponding to the type of the moving object.

[0044] This makes it possible to estimate the speeds of various moving objects with high accuracy.

[0045] In addition, the ninth invention is a speed measurement method that enables an information processing device to measure the speed of a moving body moving along a road, and the speed measurement method is configured such that a processor of the information processing device performs the following processing: obtaining a detection value of a distance, a detection value of an azimuth, and a detection value of a speed from a radar unit for detecting a moving body on a road, wherein the speed is a Doppler speed; multiplying the detection value of the distance by the detection value of the speed to calculate a measurement value of a characteristic quantity; and obtaining an estimated result of the speed based on the measurement value of the characteristic quantity, the detection value of the azimuth, and characteristic information indicating the relationship between the azimuth and the characteristic quantity at a specified speed.

[0046] Thus, similarly to the first invention, the speed of the moving object can be measured with high accuracy while suppressing the influence of the installation height.

[0047] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0048] (First Embodiment)

[0049] Figure 1 It is a side view showing a state of speed measurement by the speed measurement device 1 according to the first embodiment. Figure 2 It is a side view showing the state of speed measurement by the speed measurement device 1 in the case of different moving bodies.

[0050] like Figure 1 As shown, the speed measuring device 1 detects a moving object moving on the road using radar and measures the speed of the moving object. The speed measuring device 1 is installed at a high place above the road, for example, at a height of 5m to 6m from the ground. Specifically, the speed measuring device 1 is installed on a support column of a signal light installed at an intersection, a support column of a street light installed on the side of the road, a support column of a vehicle sensor installed on the side of the road, etc.

[0051] In this embodiment, as the detection result of the radar of the speed measurement device 1, the speed detection value V is output. m (Doppler velocity). The detected value V of this velocity m The speed V is based on the radar of the speed measuring device 1, which is different from the actual speed V of the moving body moving on the road and has an error. In particular, when the radar is installed at a high position, that is, when the radar is far away from the road surface, the speed detection value V m The error becomes larger.

[0052] In addition, the speed detection value V m The error of (Doppler velocity) depends on the height H of the moving object. For example, Figure 2 As shown in (A) and (B), even when a small two-wheeled vehicle and a large four-wheeled vehicle are traveling at the same speed V, the height H of the moving body is different. Therefore, the elevation angle α when the moving body is observed from the radar of the speed measuring device 1 is different, so the speed detection value V m Also different.

[0053] On the other hand, if the elevation angle α and the ground position of the moving object can be acquired, the detected value V of the speed can be used to determine the moving object's position. m (Doppler velocity) to estimate the actual velocity V of the moving object. However, since the elevation angle and the ground position depend on the height H of the moving object, if the height H of the moving object is unknown, the elevation angle and the ground position cannot be estimated.

[0054] However, in a conventional two-dimensional radar, although the distance and azimuth based on the radar can be obtained as detection results, information on the elevation angle α and the height H of the moving object cannot be obtained. Therefore, the accurate speed of the moving object cannot be estimated.

[0055] Therefore, in the present embodiment, the speed estimation is performed in a manner that does not depend on the height of the moving object, and even when the speed measuring device 1 is installed at a high position, the speed V of the moving object can be estimated with high accuracy. In particular, in the present embodiment, even if only the detection result of the two-dimensional radar is used, the speed of the moving object is estimated based on a variable that does not depend on the positional relationship between the radar and the moving object in the vertical direction, and thus the speed estimation can be performed in a manner that does not depend on the height of the moving object.

[0056] In addition, the velocity measurement method of the present embodiment can be used when the velocity measurement device 1 is set at a height at which the elevation angle changes beyond the allowable limit corresponding to the required measurement accuracy according to the deviation of the height of the imaginary moving body. That is, when the position of the velocity measurement device 1 is low, the deviation of the height of the moving body has almost no effect on the elevation angle, but when the position of the velocity measurement device 1 becomes higher, the elevation angle changes significantly according to the deviation of the height of the moving body, and the error of the Doppler velocity becomes significant. Therefore, when the position of the velocity measurement device 1 is high, by using the velocity measurement method of the present embodiment, the measurement accuracy of the velocity can be ensured.

[0057] In addition, if Figure 1 As shown, the elevation angle α is the complementary angle of the angle β (depression angle) in the up-down direction in which the moving object is viewed from the radar of the speed measuring device 1 with reference to the horizontal direction.

[0058] Next, an overview of the processing performed by the velocity measurement device 1 according to the first embodiment will be described. Figure 3 It is a plan view schematically showing the processing performed by the velocity measurement device 1 . Figure 4 It is a plan view schematically showing the processing performed by the velocity measurement device 1 .

[0059] like Figure 3 As shown, in this embodiment, as the detection result of the radar of the speed measurement device 1, the detection value r of the distance based on the radar is obtained. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity).

[0060] Here, the detected value r of the distance based on the radar m , the horizontal distance r from the radar to the moving object g And the elevation angle α becomes the relationship as shown in the following equation.

[0061] r m =r g / sin(α) (Formula 1)

[0062] In addition, the speed detection value V based on the radar m (Doppler velocity), the velocity V of the moving object in the horizontal direction based on the radar g And the elevation angle α becomes the relationship as shown in the following equation.

[0063] V m =V g ×sin(α) (Formula 2)

[0064] According to formula 1 and formula 2, rm ×V m As shown in the following formula.

[0065] r m ×V m =r g / sin(α)×V g ×sin(α) (Equation 3)

[0066] r m ×V m =r g ×V g (Formula 4)

[0067] Here, as shown in Formula 4, the rV value (r g ×V g =r m ×V m ) (Characteristic quantity) According to the detection value r of the distance as the detection result of the radar m And the speed detection value V m (Doppler velocity). In addition, the rV value does not depend on the elevation angle α. That is, the rV value does not depend on the height H of the moving body, and the rV value is the same regardless of whether it is a small two-wheeled vehicle or a large four-wheeled vehicle. Therefore, if the speed of the moving body is estimated based on the rV value, the speed can be estimated in a manner that does not depend on the height H of the moving body.

[0068] On the other hand, Figure 4 As shown in the figure, when the moving object moves on the road, the detected value of the azimuth angle θ m The speed measurement device 1 changes according to the position of the moving object. In addition, since the radar of the speed measurement device 1 is fixed, the positional relationship between the radar and the road does not change. Therefore, when a moving object moving on the road is detected by the radar, the detected value θ of the azimuth angle as the detection result can be used to determine the speed of the moving object. m To determine the position of the moving object. In addition, the horizontal distance r from the radar to the moving object g According to the detected value of azimuth angle θ m Therefore, the rV value becomes the detection value θ depending on the azimuth angle. m variables.

[0069] Next, an overview of the processing performed by the velocity measurement device 1 according to the first embodiment will be described. Figure 5 , Figure 6 1 is an explanatory diagram showing an outline of processing performed by the speed measurement device 1 .

[0070] In this embodiment, the horizontal axis (first coordinate axis) is set to the azimuth angle θ and the vertical axis (second coordinate axis) is set to the rV value (r g ×V g=r m ×V m ) is set on the θ-rV plane of the image sensor, and a θ-rV curve (characteristic curve) indicating the relationship between the azimuth angle θ and the rV value is set. Here, the rV value varies according to the actual speed of the moving body, but when the moving body is assumed to move at a fixed speed, the θ-rV curve (characteristic curve) is set for each specified speed.

[0071] In addition, when the azimuth angle θ is the same, the rV value increases as the actual speed of the moving object increases. Therefore, the θ-rV curve with a fast speed is located on the upper side of the θ-rV plane.

[0072] Figure 5 The example shown is a case where the actual speed of the moving object is set to 40 km / h, 50 km / h, and 60 km / h, and a θ-rV curve is plotted at each speed on the θ-rV plane.

[0073] On the other hand, in the speed measurement device 1, a detection value r of the distance is obtained as a detection result of the radar. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity). Therefore, the detection value r based on the distance m And the speed detection value V m (Doppler velocity), the measured value of rV is obtained according to formula 4 (r g ×V g =r m ×V m ), thereby setting the measured value of the rV value as the coordinate value of the vertical axis and the detected value of the azimuth angle θ on the θ-rV plane m The coordinate value of the horizontal axis is set as the measurement point P m .

[0074] Figure 5 The example shown is the measurement point P m The case where the θ-rV curve coincides with one of the θ-rV curves at each speed. In this case, the measured point P is obtained. m The velocity of the superimposed θ-rV curve is taken as the estimated value of the velocity.

[0075] Figure 6 The example shown in (A) is the measurement point P m The case where the velocity V1 is between the θ-rV curve and the θ-rV curve of the velocity V2 is located. In this case, the estimated value of the velocity is obtained by interpolation. At this time, the estimated value of the velocity is obtained according to the following formula based on the velocities V1, V2 and the interpolation coefficient a.

[0076] V=a·V1+(1-a)·V2 (Formula 5)

[0077] Here, regarding the interpolation coefficient a, based on the measurement point P m , azimuth angle θ is the detection value θ m The point P1 on the θ-rV curve of the velocity V1 and the azimuth angle θ are the detected values ​​θ m It can be set based on the positional relationship between the points P2 on the θ-rV curve of the speed V2 at that time.

[0078] In addition, when there are three or more θ-rV curves at each speed, the curve at the measuring point P is determined. m The two rV curves closest to the upper and lower sides can be interpolated.

[0079] Figure 6 The example shown in (B) is a case where the radar detection process is performed multiple times on the same moving object. In this case, multiple measurement points P are obtained through multiple detection processes. mi (i=1,…,n), according to each measurement point P mi Then, the estimated value V of each speed is calculated by using the position (coordinate) of i The final estimated value of the speed is calculated by averaging, thereby improving the accuracy of the estimated value of the speed.

[0080] Furthermore, since the azimuth angle θ changes as the moving object moves, when the detection process is performed multiple times on the same moving object, the measurement points P of each time are obtained in a state where they are arranged at intervals corresponding to the measurement timing. mi .

[0081] In the present embodiment, the estimated value V of the speed acquired by each measurement process is i The statistical processing is set to calculate the average value, but the maximum value (except for abnormal values) can also be obtained. In addition, in this embodiment, a speed measurement interval is set, and the moving body is detected and its speed is measured within the speed measurement interval. The speed measurement interval becomes the range of the azimuth angle θ in the θ-rV plane.

[0082] in addition, Figure 3 , Figure 4 This is based on a straight and horizontal road, but the road is not limited to a straight line or a horizontal line. Even if the road is curved or inclined, the speed can be estimated by the same process as long as characteristic information suitable for the site is generated.

[0083] Next, a schematic configuration of the velocity measurement device 1 according to the first embodiment will be described. Figure 72 is a block diagram showing a schematic configuration of the speed measurement device 1 .

[0084] The speed measurement device 1 includes a radar unit 11 , a storage unit 12 , and a processor 13 .

[0085] The radar unit 11 includes an antenna 21 and a signal processing unit 22. The antenna 21 radiates high-frequency radio waves and captures the reflected waves. The signal processing unit 22 is used to process the reflected waves captured by the antenna 21, and includes devices such as ADC (Analog to Digital Converter) and DSP (Digital Signal Processor). The signal processing unit 22 outputs the detected value r of the distance. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity) as the detection result.

[0086] The storage unit 12 stores programs executed by the processor 13. In addition, the storage unit 12 stores characteristic information generated in advance by the characteristic information generating device 2, specifically, the characteristic information representing the azimuth angle θ and the rV value (r g ×V g =r m ×V m ) corresponding to the θ-rV curve or the information related to the table or the mathematical expression of the relationship between ). In addition, the storage unit 12 includes devices such as a memory.

[0087] The processor 13 performs various processes related to speed measurement by executing the program stored in the storage unit 12. In the present embodiment, the processor 13 performs detection result acquisition processing, measurement point position acquisition processing, speed estimation processing, etc. The processor 13 includes a CPU and the like.

[0088] In the detection result acquisition process, the processor 13 acquires the detection value r of the distance as the detection result from the radar unit 11. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity).

[0089] In the measurement point position acquisition process, the processor 13 uses the detected value r of the distance m , the detected value of the azimuth angle θ m And the speed detection value V m , to obtain the measurement point P on the θ-rV plane m The coordinates (θ m , r m ×V m ).

[0090] In the speed estimation process, the processor 13 calculates the speed based on the measured point P. m The coordinates (θ m , r m ×V m ) and the positional relationship between the θ-rV curve at each speed to determine the θ-rV curves at the upper and lower sides closest to the measurement point. Then, the processor 13 calculates the estimated value of the speed as the estimated result of the speed by interpolation based on the speed of the θ-rV curves at the upper and lower sides.

[0091] The speed measurement device 1 may be configured such that the radar unit 11 , the storage unit 12 , the processor 13 , etc. are accommodated in one housing, but may also be configured such that a controller including the storage unit 12 and the processor 13 , etc., is separate from the radar unit 11 .

[0092] In addition, the speed measuring device 1 can also be set as a structure connected to a server (information processing device) (not shown) via a communication path such as a network, and the server performs processing related to speed measurement executed by the processor 13, specifically, detection result acquisition processing, measurement point position acquisition processing, and speed estimation processing.

[0093] Furthermore, the function of the speed measurement device 1 may be mounted on a roadside device (not shown) that exchanges vehicle travel information, traffic information, etc. with an in-vehicle terminal as one function of the roadside device.

[0094] The characteristic information generating device 2 is composed of a PC (information processing device). The characteristic information generating device 2 generates characteristic information, specifically, generates a characteristic information representing the azimuth angle θ and the rV value (r g ×V g =r m ×V m )The information related to the table or formula corresponding to the θ-rV curve of the relationship between .

[0095] In addition, the characteristic information differs depending on the installation environment of the speed measurement device 1. Therefore, the characteristic information is generated for each speed measurement device 1. That is, the characteristic information generating device 2 generates characteristic information suitable for the state of the road at the site and the installation state of the speed measurement device 1 using the learning information collected by actually moving the mobile body on the road at the site where the speed measurement device 1 is installed.

[0096] Here, the learning information is the azimuth angle θ and the rV value (r g ×V g =r m ×V m). In addition, by changing the speed of the moving body within an imaginary range to collect learning information, characteristic information at each of a plurality of speeds can be generated. In addition, if road construction is performed and the state of the road changes, learning information is collected again and characteristic information is regenerated.

[0097] Next, the procedure of processing performed by the velocity measurement device 1 according to the first embodiment will be described. Figure 8 : is a flowchart showing the process performed by the speed measurement device 1. Figure 8 Yes Figure 6 This is an example of a case where the detection process of the radar unit 11 is performed multiple times on the same moving object as shown in (B).

[0098] First, the processor 13 repeats the measurement process a predetermined number of times (n times) (ST101 to ST106).

[0099] In this measurement process, first, the processor 13 obtains the detection value r of the distance as the detection result from the radar unit 11. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity) (detection result acquisition processing) (ST102).

[0100] Next, the processor 13 detects the distance r based on the detected value r. m , the detected value of the azimuth angle θ m And the speed detection value V m , to obtain the measurement point P on the θ-rV plane m The coordinates (θ m , r m ×V m )(Measurement point position acquisition process)(ST103).

[0101] Next, the processor 13 determines the point P based on the m The coordinates (θ m , r m ×V m ) and the positional relationship between the θ-rV curve at each speed to determine the θ-rV curves at the upper and lower sides closest to the measurement point (ST104). Then, the processor 13 calculates the estimated value of the speed by interpolation based on the speed of the θ-rV curves at the upper and lower sides (speed estimation processing) (ST105).

[0102] When the above measurement process is repeated for a predetermined number of times (n times) and the estimated value V of the velocity is obtained at each time, i (i=1, ..., n), then the processor 13 calculates the estimated value V of the speed at each time. iThe estimated value of the speed is calculated by averaging (ST107). Then, the processor 13 outputs the estimated value of the speed (ST108).

[0103] (Second Embodiment)

[0104] Next, a second embodiment will be described. Note that points not particularly mentioned here are the same as those of the above-described embodiment. Fig. 9 It is an explanatory diagram showing an outline of the processing performed by the velocity measurement device 1 according to the second embodiment. Fig.10 It is a block diagram showing a schematic configuration of a velocity measurement device 1 according to the second embodiment.

[0105] In the first embodiment, the moving speed of the moving object is obtained, but in the present embodiment, speeding (speed violation) is determined, that is, whether the speed of the moving object exceeds the speed limit (threshold value) is determined. m Is it located above or below the θ-rV curve corresponding to the speed limit? m If the speed is above the θ-rV curve corresponding to the speed limit, it is determined to be overspeeding. m When the vehicle is located on the lower side of the θ-rV curve corresponding to the speed limit or in the θ-rV curve, it is determined that the vehicle is not exceeding the speed limit.

[0106] In addition, in order to improve the accuracy, the radar can also be used to perform the detection process of the moving body and the speeding determination process multiple times. In this case, the multiple determination results are integrated to obtain the final speeding determination result. At this time, for example, the determination result can also be determined by the majority decision method. That is, the number of determination results determined as speeding is compared with the number of determination results determined as not speeding, and the determination result with more times is determined as the final determination result.

[0107] like Fig.10 As shown, the structure of the speed measuring device 1 is similar to that of the first embodiment (see Figure 7 ) is the same. In addition, the storage unit 12 stores characteristic information corresponding to the speed limit prepared in advance.

[0108] The processor 13 performs the detection result acquisition process and the measurement point position acquisition process similarly to the first embodiment, but performs the overspeed determination process instead of the speed estimation process.

[0109] In the overspeed determination process, the processor 13 determines whether the speed is exceeded as a result of the speed estimation, specifically, the determination point P m Is it located on the upper or lower side of the θ-rV curve corresponding to the speed limit?

[0110] Next, the procedure of the processing performed by the velocity measurement device 1 according to the second embodiment will be described. Fig.11 : is a flowchart showing the procedure of the processing performed by the speed measurement device 1 .

[0111] First, the processor 13 repeats the measurement process a predetermined number of times (n times) (ST101 to ST111).

[0112] In this measurement process, first, the processor 13 obtains the detection value r of the distance as the detection result from the radar unit 11. m , the detected value of the azimuth angle θ m And the speed detection value V m (Doppler velocity) (ST102).

[0113] Next, the processor 13 detects the distance r based on the detected value r. m , the detected value of the azimuth angle θ m And the speed detection value V m , to obtain the measurement point P on the θ-rV plane m The coordinates (θ m , r m ×V m )(Measurement point position acquisition process)(ST103).

[0114] Next, the processor 13 determines the measurement point P m Is it located on the upper side or the lower side of the θ-rV curve corresponding to the speed limit (ST111).

[0115] When the above determination process is repeated for a predetermined number of determinations (n ​​times) and the determination results of each overspeed are obtained, the processor 13 then integrates the determination results of each overspeed to obtain a final determination result of the overspeed (ST113). Then, the processor 13 outputs the determination result of the overspeed (ST114).

[0116] In addition, in the case of speed violation supervision, in order to obtain the vehicle number by reading the license plate and to obtain the driver's facial image, the vehicle on the road is photographed by a camera. In this case, the vehicle on the road is always photographed by the camera, and the photographic image is temporarily accumulated for a predetermined time. When the speed measuring device 1 detects a speeding vehicle, the photographic image during the period when the vehicle is photographed is extracted and stored in an appropriate storage device, and is also sent to the monitoring center.

[0117] (Third Embodiment)

[0118] Next, a third embodiment will be described. Note that points not particularly mentioned here are the same as those of the above-mentioned embodiment. Fig.12It is an explanatory diagram showing characteristic information according to the third embodiment. Fig.13 It is a block diagram showing a schematic configuration of a velocity measurement device 1 according to the third embodiment.

[0119] The moving speed of a moving object greatly varies depending on the type of the moving object. For example, the moving speeds of a vehicle and a person are greatly different. Therefore, in this embodiment, characteristic information (a table or a numerical expression corresponding to a θ-rV curve) is prepared in advance for each type of moving object. Furthermore, when measuring the speed, the type of the moving object to be measured is determined, and the speed is estimated using the characteristic information corresponding to the type of the moving object.

[0120] exist Fig.12 In the examples shown in (A) and (B), the type A of the moving body (a moving body with a lower speed, such as a person, a bicycle, etc.) and the type B of the moving body (a moving body with a higher speed, such as a four-wheeled vehicle, a motorized two-wheeled vehicle, etc.) are distinguished, and characteristic information (θ-rV curve) related to type A and type B is prepared in advance.

[0121] like Fig.13 As shown, the structure of the speed measuring device 1 is similar to that of the first embodiment (see Figure 7 ) is the same. In addition, the storage unit 12 stores characteristic information of each type of moving body prepared in advance.

[0122] The processor 13 performs the detection result acquisition process, the measurement point position acquisition process, and the speed estimation process similarly to the first embodiment, but in addition, performs the moving object type determination process and the characteristic information selection process.

[0123] In the moving object type discrimination process, the processor 13 discriminates the type of the moving object (e.g., a four-wheeled vehicle, a two-wheeled motor vehicle, a person, a bicycle, etc.) that is the measurement object based on the detection result of the radar unit 11. In addition, the moving object on the road can be photographed by a camera, and the type of the moving object can be discriminated based on the photographic image.

[0124] In the characteristic information selection process, the processor 13 selects characteristic information (θ-rV curve) according to the type of the moving object.

[0125] Next, the procedure of the processing performed by the velocity measurement device 1 according to the third embodiment will be described. Fig.14 : is a flowchart showing the procedure of the processing performed by the speed measurement device 1 .

[0126] First, the processor 13 determines the type of the moving object to be measured based on the detection result of the radar unit 11 (moving object type determination process) (ST121). Then, the processor 13 selects characteristic information (θ-rV curve) corresponding to the type of the moving object (characteristic information selection process) (ST122). The subsequent steps (ST101 to ST108) are the same as those of the first embodiment.

[0127] As described above, the embodiments are described as examples of the technology disclosed in the present disclosure. However, the technology in the present disclosure is not limited thereto, and can also be applied to embodiments obtained by changes, substitutions, additions, omissions, etc. In addition, each component element described in the above-mentioned embodiment can also be combined to form a new embodiment.

[0128] Industrial Applicability

[0129] The speed measuring device and speed measuring method of the present disclosure have the effect of suppressing the influence of the installation height and measuring the speed of the moving object with high accuracy, and are useful as a speed measuring device and speed measuring method for measuring the speed of a moving object moving on a road using radar.

[0130] Description of Reference Numerals

[0131] 1: speed measuring device (information processing device); 2: characteristic information generating device; 11: radar unit; 12: storage unit; 13: processor; 21: antenna; 22: signal processing unit.

Claims

1. A speed measuring device, arranged around a road, for measuring the speed of a moving object moving along the road, the speed measuring device comprising: a radar unit that detects a moving object on a road and outputs a detected value of a distance, a detected value of an azimuth angle, and a detected value of a speed as a Doppler speed; a storage unit storing characteristic information indicating a relationship between a characteristic amount given by a product of the passing distance and the speed as the Doppler speed at a predetermined speed and the azimuth angle; and A processor estimates the speed of the moving object based on the characteristic information, the detected value of the azimuth angle, and a measured value of a characteristic amount obtained by multiplying the detected value of the distance by the detected value of the speed as the Doppler speed.

2. The speed measuring device according to claim 1, characterized in that: The radar unit is installed at a height at which an elevation angle when the moving object is viewed from the radar unit changes beyond an allowable limit due to a variation in the height of the virtual moving object.

3. The speed measuring device according to claim 1, characterized in that: The processor acquires an estimated value of speed as the estimation result of the speed based on the characteristic information at each of a plurality of speeds.

4. The speed measuring device according to claim 3, characterized in that: the processor acquires a position of a measurement point on a plane having the azimuth angle and the characteristic amount as coordinate axes based on the detected value of the distance, the detected value of the azimuth angle, and the detected value of the speed as the Doppler speed, The processor determines two characteristic curves closest to the measurement point among a plurality of characteristic curves corresponding to the characteristic information, The processor acquires the estimated value of the speed by an interpolation method based on a positional relationship between the characteristic curve and the measurement point.

5. The speed measuring device according to claim 3, characterized in that: The processor performs statistical processing on a plurality of estimated values ​​of the speed acquired by executing the detection process of the radar unit a plurality of times, and acquires a final estimated value of the speed.

6. The speed measuring device according to claim 1, characterized in that: The processor acquires, based on the characteristic information at the speed limit, a determination result regarding whether the speed exceeds the speed limit as the estimation result of the speed.

7. The speed measuring device according to claim 6, characterized in that: The processor integrates a plurality of speed determination results acquired by executing the detection process of the radar unit a plurality of times, and acquires a final speed determination result.

8. The speed measuring device according to claim 1, characterized in that: the processor determines the type of the moving object detected by the radar unit, The processor acquires an estimation result of the speed based on the characteristic information corresponding to the type of the moving object.

9. A speed measurement method, wherein an information processing device is configured to measure the speed of a moving object moving along a road, wherein: The processor of the information processing device performs the following processing: The detection value of the distance, the detection value of the azimuth angle, and the detection value of the speed are acquired from a radar unit for detecting a moving object on the road, wherein: This velocity is the Doppler velocity; calculating a measured value of the characteristic amount by multiplying the detected value of the distance by the detected value of the speed; as well as The speed estimation result is acquired based on the measured value of the characteristic amount, the detected value of the azimuth angle, and characteristic information indicating the relationship between the azimuth angle and the characteristic amount at a predetermined speed.

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