Speed ​​measurement device and speed measurement method

Abstract

To enable the speed of a mobile object to be highly accurately measured by suppressing the effect of installation height of a radar device.SOLUTION: A speed measurement device comprises: a radar unit which detects a mobile object moving along a road and outputs a detected distance value rm and detected azimuth value θm and a detected speed value Vm which is a Doppler speed; a storage unit storing a θ-rV curve (characteristic curve) which represents a relationship between a rV value (characteristic quantity) given by the product of distance and speed at a prescribed speed and an azimuth θ; and a processor estimating the speed of the mobile object on the basis of the detected distance value rm and detected azimuth value θm and the detected speed value Vm. The processor multiplies the detected distance value rm and the detected speed value Vm together to calculate a measured value of rV value (rm×Vm), and acquires the estimation result of the speed on the basis of the θ-rV value, the measured value of rV value and the detected azimuth value θm.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In order to crack down on speeding violations, technology for measuring the speed of vehicles traveling on roads has become widespread. A conventional technology for measuring the speed of vehicles on roads is known in which a radar is used to irradiate a moving object on the road with radio waves, capture the reflected waves, and process the signal (Doppler signal) contained in the reflected waves to measure the speed of the moving object (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6309328 Summary of the Invention [Problem to be solved by the invention]

[0004] Now, radar devices that detect moving objects (vehicles, people, animals, etc.) on roads are expected to be used as so-called infrastructure radars in future in automatic driving systems for vehicles. In this case, the radar devices are installed on the support poles of traffic lights installed at intersections, or on the support poles of street lights installed on the roadside, etc. This makes the installation height of the radar devices high.

[0005] However, in the conventional technology, the Doppler velocity is obtained as the velocity of the moving object as it is, and the error of the Doppler velocity from the actual velocity becomes large when the radar device is installed at a high place. In particular, when a large device with a low radio frequency is used to detect a moving object at a distance, the influence of the radar installation height is small, but when trying to meet the demand for miniaturization of the device, the influence of the radar installation height becomes large.

[0006] Therefore, a main object of the present invention is to provide a speed measurement device and a speed measurement method that can accurately measure the speed of a moving object while suppressing the effect of the installation height. [Means for solving the problem]

[0007] The speed measuring device of the present invention is a speed measuring device that is installed 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 moving bodies on the road and outputs a detected value of distance and a detected value of azimuth angle, and a detected value of speed which is Doppler velocity, a memory unit that stores characteristic information that represents the relationship between a characteristic quantity given by the product of the distance and the speed at a specified speed and the azimuth angle, and a processor that estimates the speed of the moving body based on a measured value of the characteristic quantity obtained by multiplying the detected value of distance and the detected value of speed, the characteristic information, and the detected value of the azimuth angle.

[0008] Furthermore, a speed measurement method of the present invention is a speed measurement method that causes an information processing device to perform a process of measuring the speed of a moving body moving along a road, in which a processor of the information processing device acquires a distance detection value, an azimuth detection value, and a speed detection value which is Doppler velocity from a radar unit that detects moving bodies on the road, multiplies the distance detection value and the speed detection value to calculate a measurement value of a characteristic quantity, and acquires a speed estimation result based on characteristic information that indicates the relationship between the azimuth angle and the characteristic quantity at a predetermined speed, the measurement value of the characteristic quantity, and the azimuth detection value. Effect of the Invention

[0009] According to the present invention, since the characteristic value given by the product of distance and speed does not depend on the vertical positional relationship between the radar and the moving object, it is possible to estimate the speed of the moving object based on the characteristic value, thereby making it possible to perform speed estimation that is not dependent on the height of the moving object. This makes it possible to accurately measure the speed of the moving object while suppressing the effect of the installation height. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view showing a state in which speed is measured by a speed measurement device 1 according to a first embodiment; [Diagram 2] FIG. 1 is a side view showing a state in which speed is measured by a speed measurement device 1 according to a first embodiment; [Diagram 3] FIG. 1 is a perspective view showing an overview of a process performed by a speed measuring device 1 according to a first embodiment; [Figure 4] FIG. 1 is a plan view showing an overview of a process performed in a speed measuring device 1 according to a first embodiment; [Diagram 5] FIG. 1 is an explanatory diagram showing an overview of a process performed in a speed measuring device 1 according to a first embodiment; [Figure 6] FIG. 1 is an explanatory diagram showing an overview of a process performed in a speed measuring device 1 according to a first embodiment; [Figure 7] FIG. 1 is a block diagram showing a schematic configuration of a speed measuring device 1 according to a first embodiment. [Figure 8] FIG. 1 is a flow chart showing a procedure of processing performed by the speed measuring device 1 according to the first embodiment. [Figure 9] FIG. 11 is an explanatory diagram showing an overview of a process performed in a speed measuring device 1 according to a second embodiment. [Figure 10] FIG. 1 is a block diagram showing a schematic configuration of a speed measuring device 1 according to a second embodiment. [Figure 11] FIG. 11 is a flow chart showing the procedure of processing performed by the speed measuring device 1 according to the second embodiment. [Figure 12] FIG. 13 is an explanatory diagram showing characteristic information according to the third embodiment; [Figure 13] FIG. 11 is a block diagram showing a schematic configuration of a speed measuring device 1 according to a third embodiment. [Figure 14] FIG. 11 is a flowchart showing the procedure of processing performed by the speed measuring device 1 according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The first invention made to solve the above problems is a speed measuring device that is installed 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 moving bodies on the road and outputs a detected value of distance and a detected value of azimuth angle, and a detected value of speed which is Doppler velocity, a memory unit that stores characteristic information that represents the relationship between a characteristic quantity given by the product of the distance and the speed at a specified speed and the azimuth angle, and a processor that estimates the speed of the moving body based on a measured value of a characteristic quantity obtained by multiplying the detected value of distance and the detected value of speed, the characteristic information, and the detected value of the azimuth angle.

[0012] According to this, since the characteristic value given by the product of distance and speed does not depend on the vertical positional relationship between the radar and the moving object, it is possible to estimate the speed of the moving object based on the characteristic value, and therefore it is possible to perform speed estimation that is not dependent on the height of the moving object. This makes it possible to accurately measure the speed of the moving object while suppressing the effects of the installation height.

[0015] Also, 2 The invention is configured such that the processor acquires an estimated value of speed as a result of the speed estimation based on the characteristic information for each of a plurality of speeds.

[0016] This allows a highly accurate estimate of the speed to be obtained.

[0017] Also, 3 In the invention, the processor acquires the position of the measurement point on a plane whose coordinate axes are the azimuth angle and the characteristic quantity based on the detected value of the distance, the detected value of the azimuth angle, and the detected value of the speed, identifies two characteristic curves that are closest to the measurement point among a plurality of characteristic curves corresponding to the characteristic information, and acquires an estimate of the speed by an interpolation method based on the positional relationship between the characteristic curves and the measurement point.

[0018] This makes it possible to obtain a highly accurate speed estimate without setting a large number of pieces of characteristic information (characteristic curves) for each speed at small intervals.

[0019] Also, 4 The invention is configured such that the processor statistically processes a plurality of speed estimates obtained by executing the detection process of the radar unit a plurality of times, to obtain a final speed estimate.

[0020] This makes it possible to further improve the accuracy of the final speed estimation value. Note that the statistical processing is, for example, processing such as averaging.

[0021] Also, 5 The invention is configured such that the processor acquires, as the speed estimation result, a speed determination result as to whether or not the speed limit is exceeded, based on the characteristic information for the speed limit.

[0022] This makes it possible to obtain highly accurate speed determination results.

[0023] Also, 6 In the invention, the processor is configured to integrate multiple speed determination results obtained by executing the detection process of the radar unit multiple times, and obtain a final speed determination result.

[0024] This makes it possible to further improve the accuracy of the final speed determination result.

[0025] Also, 7 The invention is configured such that the processor determines the type of moving object detected by the radar section, and obtains the speed estimation result based on the characteristic information corresponding to the type of moving object.

[0026] This makes it possible to estimate the speed of various moving objects with high accuracy.

[0027] Also, 8The invention is a speed measurement method that causes an information processing device to perform a process of measuring the speed of a moving body moving along a road, in which a processor of the information processing device acquires a distance detection value, an azimuth detection value, and a speed detection value which is Doppler velocity from a radar unit that detects moving bodies on a road, multiplies the distance detection value and the speed detection value to calculate a measurement value of a characteristic quantity, and acquires a speed estimation result based on characteristic information that indicates the relationship between the azimuth angle and the characteristic quantity at a predetermined speed, the measurement value of the characteristic quantity, and the azimuth detection value.

[0028] According to this, like the first aspect of the invention, the effect of the installation height can be suppressed and the speed of the moving object can be measured with high accuracy.

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0030] (First embodiment) Fig. 1 is a side view showing a situation in which speed is measured by the speed measurement device 1 according to the first embodiment. Fig. 2 is a side view showing a situation in which speed is measured by the speed measurement device 1 when a moving object is different.

[0031] As shown in Fig. 1, a speed measurement device 1 uses a radar to detect a moving object moving on a road and measures the speed of the moving object. This speed measurement device 1 is installed at a high place above the road, for example, at a height of 5 to 6 m from the ground. Specifically, the speed measurement device 1 is attached to a signal lamp post installed at an intersection, a street light post installed on the roadside, or a vehicle detector post installed on the roadside.

[0032] In this embodiment, the speed detection value V m (Doppler velocity) is output. The detected value of this velocity V mis a speed based on the radar of the speed measuring device 1, and differs from the actual speed V of the moving object moving on the road and contains an error. In particular, when the radar is installed at a high position, i.e., when the radar is far away from the road surface, the detected value of the speed V m The error becomes larger.

[0033] In addition, the detected speed value V m The error in the Doppler velocity depends on the height H of the moving object. For example, as shown in Figs. 2(A) and (B), even if a small two-wheeled vehicle and a large four-wheeled vehicle are traveling at the same speed V, the height H of the moving object is different. As a result, the elevation angle α when the moving object is viewed from the radar of the speed measuring device 1 is different, and the detected value V of the speed m are also different.

[0034] On the other hand, if the elevation angle α and the ground position of the moving object can be obtained, the detected speed value V m From the Doppler velocity, the actual speed V of the moving object can be estimated. However, since the elevation angle and ground position depend on the height H of the moving object, if the height H of the moving object is not known, the elevation angle and ground position cannot be estimated.

[0035] However, with a normal two-dimensional radar, although it can obtain the distance and azimuth angle based on the radar as detection results, it cannot obtain information on the elevation angle α or the height H of the moving object. As a result, it is not possible to estimate the accurate speed of the moving object.

[0036] Therefore, in this embodiment, a speed estimation is performed that is not dependent on the height of the moving body, and the speed V of the moving body can be accurately estimated even when the speed measurement device 1 is installed at a high position. In particular, in this embodiment, a speed estimation that is not dependent on the height of the moving body can be performed by estimating the speed of the moving body based on variables that are not dependent on the vertical positional relationship between the radar and the moving body using only the detection result of the two-dimensional radar.

[0037] Furthermore, the speed measurement method according to this embodiment may be used when the speed measurement device 1 is installed at a height where the elevation angle changes beyond the allowable limit according to the required measurement accuracy, depending on the expected variation in the height of the moving object. That is, when the speed measurement device 1 is located low, the elevation angle is not significantly affected by the variation in the height of the moving object, but when the speed measurement device 1 is located high, the elevation angle changes significantly depending on the variation in the height of the moving object, and the error in the Doppler velocity becomes significant. For this reason, when the speed measurement device 1 is located high, the speed measurement accuracy can be ensured by employing the speed measurement method according to this embodiment.

[0038] As shown in FIG. 1, the elevation angle α is the complement of the angle β (depression angle) in the up / down direction in which the moving body is viewed from the radar of the speed measuring device 1, with the horizontal direction as a reference.

[0039] Next, an overview of the processing performed by the speed measurement device 1 according to the first embodiment will be described. Fig. 3 is a bird's-eye view showing the overview of the processing performed by the speed measurement device 1. Fig. 4 is a plan view showing the overview of the processing performed by the speed measurement device 1.

[0040] As shown in FIG. 3, in this embodiment, the detection result of the radar of the speed measuring device 1 is a detection value r of the distance based on the radar. m and the detected azimuth angle θ m and the detected speed value V m (Doppler velocity) and

[0041] Here, the detected distance based on the radar, r m and the horizontal distance r from the radar to the moving object. g and the elevation angle α have the following relationship: r m =r g / sin(α) (Equation 1)

[0042] In addition, the radar-based speed detection value V m (Doppler velocity) and the horizontal velocity of the moving object based on the radar V gand the elevation angle α have the following relationship: V m =V g ×sin(α) (Formula 2)

[0043] According to Equation 1 and Equation 2, r m ×V m is expressed as follows: r m ×V m =r g / sin(α)×V g ×sin(α) (Equation 3) r m ×V m =r g ×V g (Formula 4)

[0044] Here, as shown in Equation 4, the rV value (r g ×V g =r m ×V m ) (characteristic quantity) is the distance detection value r m and the detected speed value V m (Doppler velocity). The rV value does not depend on the elevation angle α. In other words, the rV value does not depend on the height H of the moving object, and is the same for a small two-wheeled vehicle and a large four-wheeled vehicle. Therefore, if the speed of a moving object is estimated based on the rV value, it is possible to perform speed estimation that is not dependent on the height H of the moving object.

[0045] On the other hand, as shown in FIG. 4, when a moving object moves on a road, the detected azimuth angle θ m In addition, since the radar of the speed measuring 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 is m The position of the moving object can be determined based on the horizontal distance r g is the detected azimuth angle θ m Therefore, the rV value changes depending on the detected azimuth angle θ m It is a variable that depends on

[0046] Next, an overview of the processing performed by the speed measurement device 1 according to the first embodiment will be described.

[0047] In this embodiment, the horizontal axis (first coordinate axis) represents the azimuth angle θ, and the vertical axis (second coordinate axis) represents the rV value (r g ×V g =r m ×V m ), a θ-rV curve (characteristic curve) is set that represents the relationship between the azimuth angle θ and the rV value. Here, the rV value changes according to the actual speed of the moving object, but if it is assumed that the moving object is moving at a constant speed, a θ-rV curve (characteristic curve) is set for each predetermined speed.

[0048] Also, 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 faster speed is located on the upper side of the θ-rV plane. In the example shown in FIG. 5, the actual speed of the moving object is set to 40 km / h, 50 km / h, and 60 km / h, and the θ-rV curves for each speed are plotted on the θ-rV plane.

[0049] On the other hand, in the speed measuring device 1, the detected distance value r m , azimuth angle detection value θ m , and the detected speed value V m (Doppler velocity). Therefore, the detected value of the distance r m and the detected speed value V m Based on the Doppler velocity, the measured rV value (r g ×V g =r m ×V m ) to obtain the measured rV value and the detected azimuth angle θ m The measurement point P m can be set on the θ-rV plane.

[0050] In the example shown in Figure 5, the measurement point P m In this case, the measurement point P m The velocity of the θ-rV curve where these overlap is taken as an estimate of the velocity.

[0051] In the example shown in FIG. 6(A), the measurement point P m is between the θ-rV curve of the speed V1 and the θ-rV curve of the speed V2. In this case, the speed estimate is obtained by the interpolation method. At this time, the speed estimate is obtained by the following formula based on the speeds V1, V2 and the interpolation coefficient a. V = a V1 + (1-a) V2 (Equation 5) Here, the interpolation coefficient a is m and the azimuth angle θ is the detected value θ m When the velocity V1 is at point P1 on the θ-rV curve, and the azimuth angle θ is the detected value θ m It is sufficient to set based on the positional relationship between the velocity V2 and point P2 on the θ-rV curve when

[0052] In addition, if there are three or more θ-rV curves for each speed, the measurement point P m All that is needed is to identify the two rV curves immediately above and below the value and perform an interpolation.

[0053] The example shown in FIG. 6B is a case where the radar detection process is performed multiple times on the same moving object. In this case, multiple measurement points P mi (i=1,...,n) are obtained, and each measurement point P mi From the position (coordinates) of each time, the estimated velocity V i (i=1,...,n) are obtained. Then, the estimated velocity V i The final velocity estimate is calculated by averaging the velocities, which can improve the accuracy of the velocity estimate.

[0054] In addition, 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 point P miare obtained lined up at intervals corresponding to the measurement timing.

[0055] In this embodiment, the estimated velocity V obtained in each measurement process is i Although the average value is calculated as the statistical processing for the above, the maximum value (excluding abnormal values) may be obtained. In this embodiment, a speed measurement section is set, and a moving object is detected within the speed measurement section to measure its speed. This speed measurement section is a range of azimuth angle θ on the θ-rV plane.

[0056] Also, while Figures 3 and 4 are based on the assumption that the road is straight and horizontal, the road is not limited to being straight or horizontal. Even if the road is curved or inclined, the speed can be estimated in the same manner if characteristic information suited to the site is generated.

[0057] Next, a description will be given of a schematic configuration of the speed measurement device 1 according to the first embodiment. Fig. 7 is a block diagram showing a schematic configuration of the speed measurement device 1.

[0058] The speed measuring device 1 includes a radar unit 11, a storage unit 12, and a processor 13.

[0059] The radar unit 11 includes an antenna 21 and a signal processing unit 22. The antenna 21 emits high-frequency radio waves and captures the reflected waves. The signal processing unit 22 processes the reflected waves captured by the antenna 21, and includes devices such as an ADC (Analog to Digital Converter) and a DSP (Digital Signal Processor). The signal processing unit 22 outputs a distance detection value r m , azimuth angle detection value θ m , and the detected speed value V m (Doppler velocity).

[0060] The storage unit 12 stores a program to be executed by the processor 13. The storage unit 12 also stores characteristic information previously generated by the characteristic information generating device 2, specifically, the azimuth angle θ and the rV value (r g ×V g =r m ×V m The storage unit 12 stores information about a table or a formula corresponding to a θ-rV curve that represents a relationship between the θ-rV curve and the θ-rV curve. The storage unit 12 includes a device such as a memory.

[0061] The processor 13 performs various processes related to speed measurement by executing the programs stored in the storage unit 12. In this embodiment, the processor 13 performs a detection result acquisition process, a measurement point position acquisition process, a speed estimation process, etc. The processor 13 includes a device such as a CPU.

[0062] In the detection result acquisition process, the processor 13 receives the distance detection value r m , azimuth angle detection value θ m , and the detected speed value V m (Doppler velocity).

[0063] In the measurement point position acquisition process, the processor 13 detects the distance r m , azimuth angle detection value θ m , and the detected speed value V m Based on this, the measurement point P on the θ-rV plane m Coordinates of (θ m ,r m ×V m ) to get the

[0064] In the speed estimation process, the processor 13 m Coordinates of (θ m ,r m ×V m ) and the positional relationship between the θ-rV curve for each speed, upper and lower θ-rV curves in the immediate vicinity of the measurement point are identified. Then, the processor 13 calculates an estimated value of the speed as a speed estimation result by an interpolation method based on the speeds of the upper and lower θ-rV curves.

[0065] The speed measuring device 1 may be configured such that the radar unit 11, memory unit 12, processor 13, etc. are housed in a single housing, but the speed measuring device 1 may also be configured such that the controller including the memory unit 12, processor 13, etc. and the radar unit 11 are separate entities.

[0066] In addition, the speed measurement device 1 may be configured to be connected to a server (information processing device) (not shown) via a communication path such as a network, so that the processes related to speed measurement executed by the processor 13, specifically, detection result acquisition process, measurement point position acquisition process, and speed estimation process, etc., may be performed by the server.

[0067] Furthermore, the function of the speed measuring device 1 may be incorporated in a roadside device (not shown) as one of the functions of the roadside device for exchanging vehicle travel information, traffic information, and the like with an in-vehicle terminal.

[0068] The characteristic information generating device 2 is composed of a PC (information processing device). The characteristic information generating device 2 generates characteristic information, specifically, the azimuth angle θ and the rV value (r g ×V g =r m ×V m ) to generate a table or formula corresponding to the θ-rV curve.

[0069] Furthermore, the characteristic information differs depending on the installation environment of the speed measurement device 1. For this reason, characteristic information is generated for each speed measurement device 1. That is, the characteristic information generating device 2 generates characteristic information suited to the state of the local road and the installation state of the speed measurement device 1, using learning information collected by actually moving a mobile object on the road at the local site where the speed measurement device 1 is installed.

[0070] Here, the learning information is the azimuth angle θ and the rV value (r g ×V g =r m ×V m) is combined. In addition, by collecting learning information while changing the speed of the moving object within an expected range, it is possible to generate characteristic information for multiple speeds. Furthermore, when road construction is carried out and the road conditions change, learning information is collected again and characteristic information is regenerated.

[0071] Next, a process procedure performed in the speed measurement device 1 according to the first embodiment will be described. Fig. 8 is a flow diagram showing a process procedure performed in the speed measurement device 1. Fig. 8 shows an example in which the detection process of the radar unit 11 is performed multiple times on the same moving object, as shown in Fig. 6(B).

[0072] First, processor 13 repeats the measurement process a predetermined number of times (n times) (ST101 to ST106).

[0073] In this measurement process, first, the processor 13 receives the detected distance value r m , azimuth angle detection value θ m , and the detected speed value V m (Doppler velocity) is acquired (detection result acquisition process) (ST102).

[0074] Next, the processor 13 calculates the detected distance r m , azimuth angle detection value θ m , and the detected speed value V m Based on this, the measurement point P on the θ-rV plane m Coordinates of (θ m ,r m ×V m ) is acquired (measurement point position acquisition process) (ST103).

[0075] Next, the processor 13 detects the measurement point P m Coordinates of (θ m ,r m ×V mBased on the positional relationship between the θ-rV curve for each speed and the θ-rV curve for each speed, the upper and lower θ-rV curves in the vicinity of the measurement point are identified (ST104). Then, the processor 13 calculates an estimated value of the speed by an interpolation method based on the speeds of the upper and lower θ-rV curves (speed estimation process) (ST105).

[0076] The above measurement process is repeated a predetermined number of times (n times), and the estimated speed value V i (i=1,...,n), the processor 13 then calculates the estimated speed V i Then, the processor 13 outputs the estimated value of the speed (ST108).

[0077] Second embodiment Next, a second embodiment will be described. Note that points not particularly mentioned here are similar to the above-mentioned embodiment. Fig. 9 is an explanatory diagram showing an overview of the process performed by the speed measurement device 1 according to the second embodiment. Fig. 10 is a block diagram showing a schematic configuration of the speed measurement device 1 according to the second embodiment.

[0078] In the first embodiment, the moving speed of the moving object is acquired, but in the present embodiment, it is determined whether or not the moving object is overspeeding (speeding violation), that is, whether or not the moving object's speed exceeds the speed limit (threshold value). m Determine whether the measurement point P is located above or below the θ-rV curve corresponding to the speed limit. m If the measurement point P is located above the θ-rV curve corresponding to the speed limit, it is determined that the vehicle is speeding. m However, if the vehicle is located below or directly above the θ-rV curve corresponding to the speed limit, it is determined that the vehicle is not speeding.

[0079] In order to improve accuracy, the detection process of the moving object by the radar and the speeding determination process may be performed multiple times. In this case, the multiple determination results are integrated to obtain a final speeding determination result. At this time, the determination result may be determined by majority vote, for example. That is, the number of determination results indicating speeding is exceeded is compared with the number of determination results indicating no speeding, and the determination result with the greater number of occurrences is determined to be the final determination result.

[0080] As shown in Fig. 10, the configuration of the speed measurement device 1 is similar to that of the first embodiment (see Fig. 7). Furthermore, the storage unit 12 stores characteristic information corresponding to the speed limit that has been created in advance.

[0081] Moreover, the processor 13 performs the detection result acquisition process and the measurement point position acquisition process in the same manner as in the first embodiment, but performs the speeding determination process instead of the speed estimation process.

[0082] In the speeding determination process, the processor 13 determines whether or not the vehicle is speeding as an estimated speed. Specifically, the speed at the measurement point P m is located above or below the θ-rV curve corresponding to the speed limit.

[0083] Next, a procedure of processing performed by the speed measurement device 1 according to the second embodiment will be described.

[0084] First, processor 13 repeats the measurement process a predetermined number of times (n times) (ST101 to ST111).

[0085] In this measurement process, first, the processor 13 receives the detected distance value r m , azimuth angle detection value θ m , and the detected speed value V m (Doppler velocity) is obtained (ST102).

[0086] Next, the processor 13 calculates the detected distance r m, azimuth angle detection value θ m , and the detected speed value V m Based on this, the measurement point P on the θ-rV plane m Coordinates of (θ m ,r m ×V m ) is acquired (measurement point position acquisition process) (ST103).

[0087] Next, the processor 13 detects the measurement point P m is located above or below the θ-rV curve corresponding to the speed limit (ST111).

[0088] The above determination process is repeated a predetermined number of times (n times) to obtain the speeding determination result for each time, and then the processor 13 integrates the speeding determination results for each time to obtain a final speeding determination result (ST113).Then, the processor 13 outputs the speeding determination result (ST114).

[0089] In the case of speeding enforcement, the vehicle number is obtained by reading the license plate, and the vehicle on the road is photographed by a camera to obtain the face image of the driver. In this case, the vehicle on the road is constantly photographed by the camera, and the photographed images are temporarily stored for a predetermined period of time. When the speed measuring device 1 detects a speeding vehicle, the photographed images during the period in which the vehicle was photographed are extracted and stored in an appropriate storage device, and are also transmitted to the monitoring center.

[0090] Third embodiment Next, a third embodiment will be described. Note that points not particularly mentioned here are the same as those in the above-mentioned embodiments. Fig. 12 is an explanatory diagram showing characteristic information according to the third embodiment. Fig. 13 is a block diagram showing a schematic configuration of a speed measuring device 1 according to the third embodiment.

[0091] The moving speed of a moving object varies greatly depending on the type of the moving object. For example, the moving speed of a vehicle and a person varies greatly. Therefore, in this embodiment, characteristic information (a table or a formula corresponding to the θ-rV curve) is created in advance for each type of moving object. Then, when measuring the speed, the type of the moving object to be measured is identified, and the speed is estimated using the characteristic information corresponding to the type of the moving object.

[0092] In the example shown in FIGS. 12(A) and (B), type A of moving objects (relatively slow moving objects, such as people, bicycles, etc.) and type B of moving objects (relatively fast moving objects, such as four-wheeled vehicles, motorcycles, etc.) are distinguished, and characteristic information (θ-rV curves) relating to type A and type B is created in advance.

[0093] As shown in Fig. 13, the configuration of the speed measurement device 1 is similar to that of the first embodiment (see Fig. 7). Furthermore, the storage unit 12 stores characteristic information for each type of moving object that has been created in advance.

[0094] Moreover, the processor 13 performs detection result acquisition processing, measurement point position acquisition processing, and speed estimation processing in the same manner as in the first embodiment, but also performs moving object type discrimination processing, and characteristic information selection processing.

[0095] In the moving object type discrimination process, the processor 13 discriminates the type of moving object to be measured (for example, four-wheeled vehicle, motorcycle, person, bicycle, etc.) based on the detection result of the radar unit 11. Note that the moving object on the road may be photographed by a camera, and the type of moving object may be discriminated based on the photographed image.

[0096] In the characteristic information selection process, the processor 13 selects characteristic information (θ-rV curve) according to the type of the moving object.

[0097] Next, a procedure of processing performed by the speed measurement device 1 according to the third embodiment will be described.

[0098] First, the processor 13 determines the type of 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) according to the type of the moving object (characteristic information selection process) (ST122). The subsequent steps (ST101 to ST108) are the same as those in the first embodiment.

[0099] As described above, the embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the above embodiments to create new embodiments. [Industrial Applicability]

[0100] The speed measurement device and speed measurement method of the present invention have the effect of being able to accurately measure the speed of a moving body while suppressing the influence of installation height, and are useful as a speed measurement device and speed measurement method that uses radar to measure the speed of a moving body moving on a road. [Explanation of symbols]

[0101] 1 Speed ​​measuring device (information processing device) 2 Characteristics information generation device 11 Radar Section 12 Storage section 13 Processors 21 Antenna 22 Signal Processing Section

Claims

1. A speed measurement device that is installed around a road and measures the speed of a moving object moving along the road, a radar section for detecting a moving object on a road and outputting a detected value of distance, a detected value of azimuth angle, and a detected value of speed, which is Doppler velocity; a storage unit that stores characteristic information that indicates a relationship between a characteristic amount given by the product of the distance and the speed at a predetermined speed and the azimuth angle; a processor that estimates the speed of the moving object based on a measured value of a characteristic amount obtained by multiplying the detected value of the distance and the detected value of the speed, the characteristic information, and the detected value of the azimuth angle; A speed measuring device comprising:

2. The processor, 2. The speed measurement device according to claim 1, wherein an estimated value of the speed is obtained as the speed estimation result based on the characteristic information for each of a plurality of speeds.

3. The processor, acquiring a position of a measurement point on a plane having coordinate axes of the azimuth angle and the characteristic amount based on the detected value of the distance, the detected value of the azimuth angle, and the detected value of the velocity; Identifying two characteristic curves that are closest to the measurement point among a plurality of characteristic curves corresponding to the characteristic information; 3. The speed measuring device according to claim 2, wherein the estimated value of the speed is obtained by an interpolation method based on a positional relationship between the characteristic curve and the measurement points.

4. The processor, 3. The speed measurement device according to claim 2, wherein a final speed estimate is obtained by performing a statistical process on a plurality of speed estimates obtained by performing the detection process of the radar unit a plurality of times.

5. The processor, 2. The speed measurement device according to claim 1, further comprising: a speed determination result as to whether or not the speed limit is exceeded, as the speed estimation result, based on the characteristic information at the speed limit.

6. The processor, 6. The speed measuring device according to claim 5, wherein a final speed determination result is obtained by integrating a plurality of speed determination results obtained by executing the detection process of the radar unit a plurality of times.

7. The processor, Identifying the type of moving object detected by the radar unit; 2. The speed measuring device according to claim 1, wherein the speed estimation result is obtained based on the characteristic information corresponding to a type of moving object.

8. A speed measurement method for causing an information processing device to perform a process for measuring the speed of a moving object moving along a road, comprising: The processor of the information processing device A detection value of distance, a detection value of azimuth angle, and a detection value of speed, which is Doppler speed, are obtained from a radar unit that detects a moving object on a road; multiplying the detected distance value and the detected speed value to calculate a measured value of a characteristic quantity; A speed measurement method comprising the steps of: obtaining an estimated speed result based on characteristic information representing a relationship between the azimuth angle and the characteristic quantity at a predetermined speed, a measured value of the characteristic quantity, and a detected value of the azimuth angle.

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