JP5570266B2 - Traveling vehicle number measuring device and program - Google Patents

Description

  The present invention relates to a traveling vehicle number measuring apparatus and program for measuring the number of vehicles that have traveled (passed) on a road, and more particularly to a technique for correctly measuring the number of vehicles using a Doppler type detection sensor.

  2. Description of the Related Art Conventionally, an apparatus for measuring the number of vehicles traveling on a road is known in order to grasp the traffic volume (traffic) on main arterial roads including highways. As an example of this, a so-called loop coil system in which a large loop coil is embedded in a road and the number of vehicles passing through the place is measured (counted) based on the disturbance of the magnetic field generated by the vehicle passing over the loop coil. An image capturing device such as an electronic camera is attached to a device using a detection sensor of the above or a road crossing structure that is bridged so as to cross the road, and the road to be monitored is photographed by the image capturing device. In addition, there is a device that can specify the vehicle by performing image processing on the captured data obtained thereby, and can measure the number of vehicles that have passed through the place.

  However, the conventional apparatus adopting the loop coil system or the image processing system as described above requires large-scale construction such as burying the loop coil under the road surface or installing a road crossing structure, and has already been opened. For existing roads that are in operation, it is difficult to install traffic because of such construction, and once installed, it is difficult to move from the installation location. Has an expensive loop coil, an electronic camera, etc. and has a problem of high cost. Therefore, the conventional apparatus is not suitable for a new installation on, for example, an existing one-lane highway or a general road with relatively little traffic.

  Therefore, recently, in order to solve the above problems, a beam (radio wave) such as an ultrasonic wave or a microwave is emitted toward a passing vehicle traveling on the road, and a reflected wave from the vehicle traveling on the road is emitted. There is also known an apparatus that uses a so-called Doppler type detection sensor that detects the speed of a vehicle in response to reception, so that installation on a road is simple and can be configured at low cost. An example of an apparatus using such a Doppler type detection sensor is an apparatus described in Patent Document 1 shown below.

JP 2008-51613 A

  By the way, the Doppler type detection sensor is basically only capable of detecting the speed and moving direction of the vehicle in the first place. Therefore, a conventionally known Doppler type detection sensor as shown in Patent Document 1 described above. In an apparatus using a sensor, the number of passing vehicles is counted based only on the detected vehicle speed. However, as conventionally known, the Doppler type detection sensor can detect only one vehicle speed when a plurality of vehicles are continuously running at the same speed within the detection range. For this reason, in a device using a conventional Doppler type detection sensor, even though a plurality of vehicles that have traveled in the detection range at the same speed continue, the counting error is such that these vehicles are only counted as one at a time. Was prone to occur. This results from counting the number of passing vehicles using only the vehicle speed detected by the conventional apparatus as described above.

  The present invention has been made in view of the above points, and is small and inexpensive using a Doppler type detection sensor capable of appropriately measuring the number of vehicles that have traveled (passed) on a road without miscounting. An object of the present invention is to provide a traveling vehicle number measuring device and program.

The traveling vehicle number measuring device according to the present invention includes a sensor unit that radiates a transmission wave to a vehicle that is traveling within an arbitrary measurement range set in advance on one lane, and that receives a reflected wave from the vehicle. A frequency analysis means for extracting a frequency spectrum having the largest amplitude value by frequency-analyzing a difference wave between the transmission wave and the reflected wave, and obtaining the speed of the vehicle running from the extracted frequency spectrum; Recording means for acquiring the vehicle speed and the extracted amplitude value in time series, and recording the time displacement of the vehicle speed and the time displacement of the amplitude value, respectively, and measuring time according to the detection of the vehicle speed. On the one hand, the elapsed time taken from when the vehicle enters the measurement range until it finishes passing according to ending the time measurement based on the time displacement of the recorded amplitude value With determining comprises a measurement means for counting one vehicle number for each elapsed time these fixed.

As a preferred embodiment of the present invention, the measuring means determines, as the elapsed time, a time required for the recorded amplitude value to increase a predetermined number of times and decrease a predetermined number of times.
Further, the apparatus further comprises speed extracting means for extracting a maximum speed from the recorded vehicle speed within the determined elapsed time, and the measuring means multiplies the determined elapsed time and the extracted maximum speed. According to the values, predetermined vehicle types having different vehicle lengths are identified, and the number of the one vehicle is counted for the identified vehicle type .

According to the present invention, a differential wave between a transmitted wave radiated to a vehicle traveling in an arbitrary measurement range set in advance on one lane and a reflected wave from the vehicle is extracted by frequency analysis. The vehicle's speed and amplitude are acquired and their time displacement is recorded. Then, based on the recorded vehicle speed and amplitude value, an elapsed time required for the vehicle to enter the measurement range and finish passing, is determined for each determined elapsed time, that is, the vehicle speed and amplitude. The number of one vehicle is counted according to the determination of the elapsed time based on the value. That is, the number of passing vehicles is not counted using only the detected vehicle speed, but the amplitude value is used in addition to the vehicle speed. As a result, it is possible to accurately grasp the movement mode of the vehicle within the measurement range and count the number of passing vehicles only by using a Doppler type detection sensor. In addition, since such a device is small and inexpensive and easy to carry, it can be easily installed on the side of the road and can be moved easily.

  Furthermore, by counting the number of passing vehicles using the amplitude value in addition to the vehicle speed, it is difficult to correctly measure the number of vehicles with a conventional device using a Doppler type detection sensor. Even if a plurality of vehicles that traveled in are consecutive, those vehicles can be counted separately for each vehicle. That is, the number of vehicles that have traveled (passed) on the road can be appropriately measured without miscounting.

  The present invention can be constructed and implemented not only as a device invention but also as a method invention. Further, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, or can be implemented in the form of a storage medium storing such a program.

  According to the present invention, instead of using only the vehicle speed detected by the Doppler detection sensor, the number of passing vehicles is counted using the amplitude value in addition to the vehicle speed. In the small and inexpensive traveling vehicle number measuring device using this detection sensor, it is possible to appropriately measure the number of vehicles that have traveled (passed) on the road of one monitored lane. .

It is a conceptual diagram which shows one Example of the traveling vehicle number measuring device which concerns on this invention. It is a conceptual diagram which shows an example of the installation aspect in the road of the one lane of one side of the traveling vehicle number measuring device which concerns on this invention. It is a flowchart which shows one Example of a traveling vehicle number measurement process. It is a transition diagram of the speed and amplitude value for explaining the traveling vehicle number measurement processing concretely. It is a transition diagram of the speed and amplitude value for concretely explaining the traveling vehicle number measurement processing, and shows a case where two continuous vehicles within the measurement range travel and pass at the same speed.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a conceptual diagram showing an embodiment of a traveling vehicle number measuring device according to the present invention. The traveling vehicle number measuring device according to the present invention includes a sensor unit A and a passing vehicle detection unit B. The sensor unit A is installed on the side of a road such as a shoulder as shown in FIG. 2 described later. For example, in order to measure and detect the speed of a vehicle traveling on one lane on one side by the Doppler method, a sensor (A) is used. Fires radially across the entire lane (running lane) to be monitored, receives a reflected wave from a vehicle traveling on the lane according to the radiation of the beam, and outputs the received reflected wave as an output signal You can do that. That is, the sensor unit A is a Doppler type detection sensor and, as is conventionally known, a radio wave emitting unit that radiates a beam (radio wave: transmission wave) having a predetermined transmission frequency (for example, 24.15 GHz). 1, a reflected wave receiving unit 2 that receives a reflected wave from a vehicle traveling on one lane, and a difference wave between a transmitted wave radiated to a passing vehicle detection unit B and a reflected wave from the vehicle And a signal output unit 3 for outputting.

  On the other hand, the passing vehicle detection unit B includes a signal reception unit 11, a frequency analysis unit 12, a vehicle number measurement unit 13, and a measurement result output unit 14. The signal receiving unit 11 acquires a differential wave from the reflected wave output from the sensor unit A. First, the frequency analysis unit 12 performs frequency analysis on a differential wave obtained by comparing the acquired reflected wave with a beam (radio wave: transmission wave) emitted from the sensor unit A to obtain a frequency spectrum distribution. Since any known process for obtaining the frequency spectrum distribution by the frequency analysis may be used, detailed description thereof is omitted here.

  Next, the frequency spectrum having the largest amplitude value is specified according to the frequency spectrum distribution. That is, one frequency spectrum having the maximum amplitude value (protruding as compared with others) is extracted based on the frequency spectrum distribution. At this time, a frequency spectrum having the maximum amplitude value among one or more frequency spectra within a predetermined bandwidth may be extracted as a representative. Then, the vehicle speed derived from the specified frequency spectrum and the amplitude value of the specified frequency spectrum are sent to the vehicle number measuring unit 13 every predetermined time (for example, 1/10 second unit). Note that even when one vehicle is not traveling within the measurement range, that is, when the speed is zero, the speed of the vehicle is sent as “0”.

In order to calculate the vehicle speed based on the frequency (Doppler frequency) of the specified frequency spectrum, a Doppler formula as shown in Equation 1 is used.
(Equation 1)
f = 2V / λ = 161 · V
Here, f is the Doppler frequency, V is the speed of the vehicle (m / sec), and λ is the wavelength of the beam (radio wave) emitted from the radio wave emission unit 1. For the wavelength λ, when the transmission frequency of the beam (radio wave) emitted from the radio wave emission unit 1 is 24.15 GHz, for example, “2 / λ” in Equation 1 is approximately “161” (λ = 0.012422 meters) . Then, since the speed (m / s) can be converted to 3.6 times (60 x 60/100) to convert the speed (km / h) to the speed (km / h), the vehicle speed (speed) is calculated by the following formula 2. Will be.
(Equation 2)
V = f × 3.6 / 161 (km / h)

  As a method for obtaining the Doppler frequency f, a pulse count method, a reciprocal method, a frequency measurement method, and the like are conventionally known. Of these, the frequency measurement method is easy to improve the signal-to-noise ratio by signal processing, and has a characteristic that it is very sensitive compared to other methods, so the number of traveling vehicles according to the present invention is measured. It is most suitable for use in equipment.

  The vehicle number measuring unit 13 measures (counts) the number of vehicles that have passed based on the vehicle speed sent from the frequency analyzing unit 12 and the amplitude value of the specified frequency spectrum. Details of the process of measuring the number of passing vehicles will be described later (see FIGS. 3 and 4). The measurement result output unit 14 outputs the measured number of passing vehicles to an external device such as a traffic control control device provided in a road control center or the like that collectively manages road conditions.

  Here, FIG. 2 shows an example of a mode of installation of the traveling vehicle number measuring device according to the present invention on a one-lane road. As shown in FIG. 2, the traveling vehicle number measuring device according to the present invention overlooks the entire one lane of any one of the roads on one lane such as a road shoulder (or a guardrail installed in a median). It is installed in any place that can

  When the traveling vehicle number measuring device is installed at an arbitrary position as described above, the radio wave emission unit 1 (see FIG. 1) of the sensor unit A particularly covers all one lane to be monitored. In addition, a beam W (radio wave) such as an ultrasonic wave, a microwave, or a millimeter wave reaches the vehicle in a predetermined range (for example, a narrow range of several to several tens of meters) in a direction facing the vehicle M traveling on the lane. The reflected beam receiving unit 2 (see FIG. 1) can emit the emitted beam (radio wave) from any one or a plurality of vehicles M traveling on the lane. The angle and height of the radio wave emitting unit 1 and the reflected wave receiving unit 2 of the sensor unit A are adjusted so that the reflected wave can be received. For example, the sensor unit A is disposed in a state where the sensor unit A is inclined about 45 degrees obliquely with respect to the traveling direction of the vehicle in the lane to be monitored. The measurement range by the sensor unit A at this time is set to a narrow range that can detect that a vehicle traveling at a predetermined speed or less enters the measurement range one by one and goes out of the measurement range. .

  Next, the process for measuring the number of passing vehicles by the vehicle number measuring unit 13 will be described with reference to FIGS. FIG. 3 is a flowchart showing an embodiment of the traveling (passing) vehicle number measuring process by the vehicle number measuring unit 13. The process starts when the apparatus is turned on and ends when the apparatus is turned off. FIG. 4 is a transition diagram of speed and amplitude values for specifically explaining the traveling vehicle number measurement process. The horizontal axis indicates time, and one of the vertical axes indicates speed and the other indicates amplitude value.

  Step S1 executes an initial process. As the initial processing, for example, an elapsed time, an amplitude value increase count value, an amplitude value decrease count value, etc., which will be described later, are initialized (cleared). Step S2 determines whether or not there is vehicle speed detection within the measurement range. If the vehicle has entered the measurement range, detection of the vehicle speed is sent from the frequency analysis unit 12 (see FIG. 1) every predetermined time. If it is determined that the vehicle speed is not detected within the measurement range (NO in step S2), there is no speed vehicle recorded in the past because no vehicle has entered the measurement range. It is cleared (step S14). Then, returning to the process of step S2, the process waits until the vehicle speed is detected (that is, until the vehicle enters the measurement range).

  If it is determined that the vehicle speed is detected within the measurement range (YES in step S2), the elapsed time is counted (step S3). At this time, if the elapsed time is “0”, the elapsed time is newly started. On the other hand, if the elapsed time is not “0”, that is, the elapsed time has already been started in the previous processing. Just keep counting the elapsed time. In the example shown in FIG. 4, the vehicle speed is “0” until time “10”, and the vehicle speed is detected at time t1, so that it can be determined that the vehicle has entered the measurement range at time At the time t1, time measurement is started from the time t1. Step S4 acquires the vehicle speed based on the frequency analysis result by the frequency analysis unit 12, and records this as a speed sample. Step S5 acquires the amplitude value of the frequency spectrum specified based on the frequency analysis result by the frequency analysis part 12, and records this as an amplitude value sample. In FIG. 4, the velocity samples that are sequentially acquired at predetermined time intervals as time passes are indicated by black circles, and the amplitude value samples are indicated by squares.

  In step S6, it is determined whether or not the amplitude value (amplitude value sample) acquired this time has increased compared to the amplitude value acquired at the previous time, that is, whether or not the amplitude value is large. When it is determined that the amplitude value acquired this time has not increased (the amplitude value is not large) compared to the amplitude value acquired at the previous time (NO in step S6), the count value of the decrease in the amplitude value Is incremented and the process jumps to step S8. On the other hand, when it is determined that the amplitude value acquired this time is higher than the amplitude value acquired at the previous time (the amplitude value is large) (YES in step S6), the number of increase times of the amplitude value is counted. The value is incremented, and it is determined whether or not the increase of the amplitude value continues continuously for a predetermined number of times (N times) based on the increase number count value (step S7). If it is determined that the increase in the amplitude value continues for a predetermined number of times (N times) (YES in step S7), the subsequent step S8 is performed. On the other hand, when it is determined that the increase in the amplitude value has not continued for a predetermined number of times (N times) (NO in step S7), the process returns to step S2 and the processes from step S2 to S7 are repeated. Run. That is, it is monitored that the increase in amplitude value continues N times.

  In step S8, it is determined whether or not the decrease in the amplitude value continues for a predetermined number of times (M times) based on the count value of the decrease in the amplitude value. If it is determined that the decrease in the amplitude value has not continued for a predetermined number of times (M) (NO in step S8), the process returns to step S2 and the processes from step S2 to S8 are repeatedly executed. . That is, it monitors that the amplitude value continues to decrease M times. If it is determined that the decrease in the amplitude value continues for a predetermined number of times (M times) (YES in step S8), the elapsed time during counting is determined (step S9). Step S10 extracts the maximum speed from the recorded speed samples.

In step S11, a multiplication value obtained by multiplying the extracted maximum speed by the measurement time (this corresponds to the length of the vehicle) is compared with a predetermined reference value. Here, the reference value is a predetermined vehicle length corresponding to a vehicle type such as a large size or a small size. If it is determined that the multiplication value is larger than the reference value (YES in step S11), the vehicle type is specified as “large” with a long vehicle length, and the number of vehicles of the vehicle type is counted (that is, an increase of one vehicle). ( Count) (Step S12). If it is determined that the multiplication value is smaller than the reference value (NO in step S11), the vehicle type is specified as “small” with a short vehicle length, and the number of vehicles of the vehicle type is counted (that is, an increase of one vehicle). ( Count) (Step S13). After the process of step S12 or step S13 is completed, the process returns to step S1.

  As described above, while the speed is detected, the rise of the amplitude value N consecutive times and the fall of the amplitude value M consecutive times are monitored and acquired from the rise start time to the fall end time. The largest vehicle speed is extracted from a large number of vehicle speeds. Then, the number of vehicles for each vehicle type is counted according to the extraction of the vehicle speed. Therefore, the number of extractions of the vehicle speed is equal to the number of passing vehicles (total number, not vehicle type).

  That is, when one vehicle passes through the measurement range of the sensor unit A, the speed sample (f1) and the amplitude value sample (f2) transition as shown in FIG. In this example, the time from time t1 to time t3 corresponds to “elapsed time”, and the number of vehicles is measured based on the speed sample and the amplitude value sample acquired during that time. Here, the “elapsed time” is a calculation time required for one vehicle to enter the measurement range and go out of the measurement range. When only one vehicle is traveling within the measurement range, the amplitude value increases as the vehicle approaches the sensor unit A, and the amplitude value decreases as the vehicle moves away from the measurement range. An amplitude value sample curve f2 including a peak at time t2 is obtained. The peak of the amplitude value appears when the vehicle is closest to the sensor unit A (for example, a position facing the front of the sensor unit A as indicated by a dotted line in FIG. 1).

  Then, after the time t3 when the one vehicle passes through the measurement range of the sensor unit A, the speed once becomes “0” (determined that no speed is detected). When another vehicle enters the measurement section after the vehicle has passed the measurement section (time t4), the speed of the vehicle is detected (determined that there is speed detection) and the “elapsed time” As the time measurement is newly started, the speed sample (f3) and the amplitude value sample (f4) are acquired with the passage of time, and the number of vehicles corresponding to the other vehicle is similarly counted based on these samples. Done.

  In the present embodiment, the number of vehicles is not counted when the sensor unit A is closest to the sensor unit A according to the peak detection of the amplitude value, but as described above, the amplitude value rises N times and continues M times. By monitoring the decrease in the amplitude value, the number of vehicles can be determined by detecting a combination of one vehicle entering the measurement range and correspondingly going out of the measurement range. It counts as one unit.

  Here, a predetermined number of times (N times) for determining whether or not the increase in amplitude value described above continues continuously, and whether or not the decrease in amplitude value continues continuously. For the predetermined number of times (M times), an appropriate number of times experimentally obtained by the size of the measurement range by the sensor unit A, the vehicle speed acquired from the frequency analysis unit 12 and the sample acquisition time of the amplitude value, etc. is set as a fixed value in advance Just keep it. This is because, for example, when one passing vehicle is a large bus or a transport truck having a longer vehicle length than a passenger car or the like, two amplitude peak values can appear at the front end and the rear end of the vehicle. Therefore, in order to prevent double counting of the vehicle in such a case and to correctly count it as one vehicle, by setting the reference such as N times and M times as described above, one vehicle can be measured. This is in order to correctly detect that the vehicle has entered the vehicle and correspondingly moved out of the measurement range, while removing the influence of the amplitude value variation that may occur during that time.

  By the way, when the speed of a vehicle traveling on a highway is measured, the speed of each of the plurality of vehicles traveling in the same lane often does not have a large difference. Even if the measurement range of the part A is set to a narrow range as described above, the second vehicle may enter the measurement range before the first vehicle passes the measurement range. In such a case, a plurality of vehicles traveling at the same speed within the measurement range may pass continuously. In this embodiment, the number of vehicles can be counted correctly even in such a case. This will be described with reference to FIG. FIG. 5 is a transition diagram of speed and amplitude values for specifically explaining the traveling vehicle number measurement process, and shows a case where two consecutive vehicles travel and pass through the measurement range at the same speed.

  When two vehicles pass through the measurement range of the sensor unit A continuously at the same speed, the speed sample (f1) and the amplitude value sample (f5) transition as shown in FIG. As the speed sample curve f1, only one speed sample is obtained every predetermined time because two vehicles are traveling at the same speed. On the other hand, when the amplitude value sample curve f5 is seen, it is 2 between the time when the speed sample curve f1 rises to “0”, as in the case where a large bus or a transport truck with a long vehicle length as described above passes. The peak of two amplitude values appears (however, the drop in the amplitude value between the peaks is larger than that in the case where a vehicle with a long vehicle length described above passes).

In the example shown here, by performing the processing loop of FIG. 3 once, the time elapsed from time t1 to time t3 is counted as “elapsed time 1 ” of the first vehicle, and then the processing loop of FIG. By performing it once more, the time from time t3 to time t4 is counted as “elapsed time 2 ” of the second vehicle. The number of vehicles is counted for each elapsed time 1 and 2 respectively . That is, when two vehicles enter the measurement range before the first vehicle passes through the measurement range (in this case, the speed is “0” until the second vehicle finishes passing). In other words, an amplitude value sample curve f5 including peaks (time t2, time t4) within each of “elapsed time 1” and “elapsed time 2” is obtained. In this embodiment, the maximum value of the speed is output for each of the “elapsed time 1” and “elapsed time 2” and the vehicle is counted for one vehicle. Can be measured. Note that the “elapsed time 1” and “elapsed time 2” are calculated times required for each vehicle to enter the measurement range and go out of the measurement range.

  As described above, in the present invention, a frequency analysis is performed on a differential wave between a transmission wave radiated to a vehicle traveling within an arbitrary measurement range set in advance on one lane and a reflected wave from the vehicle. The vehicle speed and the amplitude value extracted by this are acquired, and those time displacements are recorded. Then, based on the recorded vehicle speed and amplitude value, an elapsed time required for the vehicle to enter the measurement range and finish passing is determined. The number of vehicles is counted according to the determination of the elapsed time based on the value. That is, the number of passing vehicles is not counted using only the detected vehicle speed, but the number of passing vehicles is counted using a combination of the vehicle speed and an amplitude value. As a result, it is possible to accurately grasp the movement mode of the vehicle within the measurement range and count the number of passing vehicles only by using a Doppler type detection sensor. Since these devices are small, inexpensive and easy to carry, they are easy to install on the side of the road and can be moved around the installation location.

  Further, in the traveling vehicle number measuring device according to the present invention, it is difficult to correctly measure the number of vehicles with a conventional device using a Doppler type detection sensor, and a plurality of vehicles traveling at the same speed are consecutive. Even so, it is possible to count each vehicle separately without counting them as one unit, so miscounting the number of vehicles that have traveled (passed) on the road Therefore, it is possible to measure appropriately.

In the above-described embodiment, the signal reception unit 11 and the frequency analysis unit 12 are included on the passing vehicle detection unit B side. However, the configuration is not limited thereto, and the signal reception unit 11 and the frequency analysis unit 12 are arranged on the sensor unit A side. The passing vehicle detection unit B receives the vehicle speed and amplitude value based on the frequency spectrum distribution as the frequency analysis result by the frequency analysis unit 12 from the sensor unit A, and receives the received vehicle speed and amplitude. The number of passing vehicles may be measured based on the value.
In the above-described embodiment, an example is shown in which the vehicle type is classified into only two types, “small” or “large”. However, the present invention is not limited to this. Needless to say, the vehicle types may be classified according to differences.

  In addition, the traveling vehicle number measuring device according to the present invention is not limited to the configuration in which both the sensor unit A and the passing vehicle detection unit B as shown in FIG. 1 are incorporated, but one or more externally configured sensor units. Needless to say, the configuration may be such that A and the passing vehicle detection unit B are communicably connected to each other. In that case, the signal output unit 3 and the signal receiving unit 11 described above are, for example, a communication interface such as USB (Universal Serial Bus), IEEE1394 (Itriple 1394), Bluetooth (trademark), infrared transceiver, and LAN. It may be a network interface that can transmit and receive signals, data, and the like via a wired or wireless communication network such as (Local Area Network), the Internet, or a telephone line.

  In the case of the network interface configuration as described above, signals are received from each of a large number of sensor units A arranged at a number of points far away on the road via a communication network, and vehicles passing at each point are received. It is also possible to make it possible to perform the number measurement by only one passing vehicle detection unit B. Then, for example, the passing vehicle detection unit B is arranged in a road control center or the like, and a large number of sensor units A arranged at each point are connected to each other by a wired or wireless communication network. By centrally managing the output signal output from the point and grasping the number of passing vehicles over the entire road, only the small sensor unit A that has a simpler configuration and can be carried can be placed beside the road at any point. It can be realized just by installing it in the very convenient.

A ... Sensor unit B ... Passing vehicle detection unit M ... Vehicle W ... Beam (radio wave)
DESCRIPTION OF SYMBOLS 1 ... Radio wave emission part 2 ... Reflected wave receiving part 3 ... Signal output part 11 ... Signal receiving part 12 ... Frequency analysis part 13 ... Vehicle number measurement part 14 ... Measurement result output part

Claims (4)

Sensor means for radiating a transmission wave to a vehicle running in an arbitrary measurement range set in advance on one lane and receiving a reflected wave from the vehicle;
A frequency analysis means for extracting a frequency spectrum having the largest amplitude value by frequency-analyzing a difference wave between the transmission wave and the reflected wave, and obtaining a speed of a running vehicle from the extracted frequency spectrum;
Recording means for acquiring the obtained vehicle speed and the extracted amplitude value in time series, and recording the time displacement of the vehicle speed and the time displacement of the amplitude value, respectively;
In response to the detection of the vehicle speed, the time measurement is started, while the time measurement is ended based on the time displacement of the recorded amplitude value, so that the vehicle finishes passing after the vehicle enters the measurement range. A traveling vehicle number measuring device comprising: a measuring means that counts the number of vehicles for each determined elapsed time as well as determining the elapsed time required until the time.   2. The traveling vehicle number measuring device according to claim 1, wherein the measuring unit determines, as the elapsed time, a time required for the recorded amplitude value to increase a predetermined number of times and then decrease a predetermined number of times. Further comprising speed extracting means for extracting a maximum speed from the recorded vehicle speed within the determined elapsed time;
The measuring means identifies predetermined vehicle types having different vehicle lengths according to a multiplication value of the determined elapsed time and the extracted maximum speed, and counts the number of one vehicle for the identified vehicle type. The traveling vehicle number measuring device according to claim 1 or 2. On the computer,
A procedure for radiating a transmission wave to a vehicle traveling in an arbitrary measurement range set in advance on one lane and receiving a reflected wave from the vehicle;
The frequency of the difference wave between the transmitted wave and the reflected wave is analyzed to extract the frequency spectrum having the largest amplitude value, and the procedure for obtaining the speed of the running vehicle from the extracted frequency spectrum;
A procedure for acquiring the obtained vehicle speed and the extracted amplitude value in time series, and recording the time displacement of the vehicle speed and the time displacement of the amplitude value, respectively.
In response to the detection of the vehicle speed, the time measurement is started, while the time measurement is ended based on the time displacement of the recorded amplitude value, so that the vehicle finishes passing after the vehicle enters the measurement range. A program for determining the elapsed time required until and executing a procedure for counting the number of vehicles for each determined elapsed time.

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