JP2013003646A - Electric vehicle identification apparatus and electric vehicle identification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus or a method for distinguishing an electric vehicle and a gasoline vehicle, etc. from each other.SOLUTION: A vehicle 5 entering a sensing area is sensed and information of sound generated by the sensed vehicle 5 is collected through a directional microphone 3. A determining part 10 determines whether or not a characteristic particular to an electric vehicle (for example, the sound pressure is lower than a threshold value) is included in the collected sound information. When the characteristic is included, the vehicle 5 is determined to be an electric vehicle, and when the characteristic is not included, the vehicle 5 is determined to be not an electric vehicle.

Description

  The present invention relates to an electric vehicle that travels on a road by driving a motor with a mounted battery. In addition, the electric vehicle in the present invention may be an electric vehicle (EV: Electric Vehicle) that travels only by a motor, or a hybrid vehicle (HEV: Hybrid Electric Vehicle) that uses a motor and an engine together travels only by a motor. Shall be included.

The spread of HEV is already progressing rapidly, but if EV becomes more widespread, it is expected that the urban environment will be improved by a significant decrease in CO ₂ and NO _X (for example, see Non-Patent Document 1). In particular, since the NO _X has a large direct impact on human health is a air pollutants, which it is very desirable to reduce.

Published by Denchu Research News 463, Central Research Institute of Electric Power, December 25, 2009

  In reality, however, engine-driven cars that use gasoline or light oil as fuel (hereinafter referred to as gasoline cars) are expected to coexist. Under such circumstances, for example, if it is intended to realize a clean area with reduced air pollutants limited to at least residential areas, hospitals, schools, and school roads, in such areas, It is necessary to take measures to prevent gasoline cars from entering. For example, it may be possible to open and close a gate that enters a clean area by determining whether or not the vehicle is an electric vehicle. In this case, a device for automatically discriminating between an electric vehicle and a gasoline vehicle is necessary. However, such a technique has not been proposed yet.

  In view of this problem, an object of the present invention is to provide an apparatus or a method for distinguishing an electric vehicle such as an electric vehicle from a gasoline vehicle.

(1) An electric vehicle identification device according to the present invention includes a vehicle detector that detects a vehicle that has entered a detection area, a sound information collection unit that collects information on sound generated by the detected vehicle, and collected sound information. And a determination unit for determining whether or not the characteristic of the sound unique to the electric vehicle is included.
In the electric vehicle identification device configured as described above, focusing on the characteristic of the sound unique to the electric vehicle, and determining whether such characteristic is included in the collected sound information, A gasoline vehicle or the like can be distinguished from each other.

(2) Moreover, in the electric vehicle identification device according to (1), the determination unit can perform determination based on the collected sound distribution.
For example, even when an electric vehicle emits artificial sound, the distribution of sound (power spectrum distribution) of the electric vehicle is different from that of a gasoline vehicle or the like. Therefore, the electric vehicle can be identified from a gasoline vehicle or the like based on the sound distribution.

  In the electric vehicle identification device of (2) above, the determination unit determines that the vehicle is a hybrid vehicle when the collected sound distribution includes the engine sound distribution and the artificial sound distribution. Is also possible. Thereby, it becomes possible to identify a hybrid vehicle (HEV) and an electric vehicle (EV).

(3) Moreover, in the electric vehicle identification device according to (1) or (2), the determination unit may perform determination based on the sound pressure of the collected sound.
In this case, an electric vehicle that does not emit artificial sound has a sound pressure level that is considerably lower than that of a gasoline vehicle or the like. Therefore, the electric vehicle can be identified from a gasoline vehicle or the like by providing a threshold value.

(4) Moreover, in the electric vehicle identification device in any one of said (1)-(3), you may make it a determination part perform determination based on the frequency of the collected sound.
For example, when only the artificial sound emitted by the electric vehicle includes sound of a specific frequency, the electric vehicle can be easily identified from a gasoline vehicle or the like depending on whether or not the collected sound includes the frequency.

(5) On the other hand, the electric vehicle identification method of the present invention senses a vehicle that has entered the sensing area, collects sound information generated by the sensed vehicle, and collects information on the sound into the characteristic information of the electric vehicle. Is included, and if the feature is included, it is an electric vehicle, and if it is not included, it is determined that the vehicle is not an electric vehicle.
In the electric vehicle identification method as described above, paying attention to the characteristic of the sound unique to the electric vehicle, and determining whether or not such characteristic is included in the collected sound information, the electric vehicle and the others Can be distinguished from each other.

  According to the electric vehicle identification apparatus or method of the present invention, an electric vehicle and other gasoline vehicles can be distinguished from each other.

It is a figure which shows an example of the positional relationship of the motor vehicle which drive | works a road, and each sensor in the electric vehicle identification device which concerns on one Embodiment of this invention. It is a block diagram of the electric vehicle identification device which concerns on 1st Embodiment. It is a flowchart which shows the processing operation of a determination part. It is a block diagram of the electric vehicle identification device which concerns on 2nd Embodiment. It is a flowchart which shows the processing operation of a determination part. It is an example of the flowchart performed when it is necessary to identify a hybrid vehicle (HEV) and an electric vehicle (EV).

<< First Embodiment >>
FIG. 1 is a diagram illustrating an example of a positional relationship between an automobile traveling on a road and each sensor in the electric vehicle identification device according to the embodiment of the present invention.
In the figure, a vehicle detector 2, a directional microphone 3, and a control box 4 that accommodates a circuit connected thereto are attached to a column 1 installed on a road R. As the vehicle detector 2, various known devices can be used, and for example, a far infrared sensor, an image sensor, an ultrasonic sensor, a loop coil, or an optical beacon can be used. The vehicle detector 2 has a sensing area as shown in the figure, for example. The automobile 5 entering the sensing area is sensed by the vehicle sensor 2.

  On the other hand, the directional microphone 3 has a strong directivity, and can, for example, sensitively collect sounds generated in a spatial region with hatched lines in the figure. The plane where the space area intersects the road R is generally coincident with the sensing area. However, the surface may be slightly shifted in the traveling direction of the automobile 5 from the sensing area. In short, when one vehicle is detected by the vehicle detector 2, the directional microphone 3 only needs to be arranged so that only the sound emitted by the vehicle can be collected. Moreover, you may install the vehicle sensor 2 and the directional microphone 3 in a mutually separate support | pillar.

  FIG. 2 is a block diagram of the electric vehicle identification device according to the first embodiment. In the figure, the output of the vehicle detector 2, that is, the vehicle detection information is input to the determination unit 10. On the other hand, the output of the directional microphone 3 is input to the sound pressure calculation unit 6, and the sound pressure obtained by the calculation is input to the determination unit 10. The directional microphone 3 and the sound pressure calculation unit 6 constitute a sound information collection unit 9 that collects information (here, sound pressure) of sound generated by the automobile 5.

  FIG. 3 is a flowchart showing the processing operation of the determination unit 10. In the figure, the determination unit 10 waits until a new vehicle is sensed while repeating the determination of whether or not a new vehicle has been sensed (step S1). When sensed, the determination unit 10 determines whether or not the sound pressure level is lower than a threshold value (step S2). Here, when lower than a threshold value, it determines with a target being an electric vehicle (step S3). Conversely, if it is equal to or greater than the threshold value, it is determined that the vehicle is not an electric vehicle, that is, a gasoline vehicle or the like (step S4). After the determination, the same processing is performed after waiting for the next vehicle detection (step S1).

  As described above, in the above-described electric vehicle identification device, attention is paid to the low sound pressure characteristic of the sound unique to the electric vehicle, that is, the electric vehicle has a sound pressure level considerably lower than that of a gasoline vehicle or the like. By providing a threshold value, the electric vehicle can be easily identified from a gasoline vehicle or the like.

<< Second Embodiment >>
The second embodiment relates to the identification of an electric vehicle in the case where an artificial sound is generated as a preventive safety measure against an electric vehicle having too low traveling sound being hardly noticed by a pedestrian or the like.

  FIG. 4 is a block diagram of the electric vehicle identification device according to the second embodiment. In the figure, the output of the vehicle detector 2, that is, the vehicle detection information is input to the determination unit 10. On the other hand, the output of the directional microphone 3 is input to the sound pressure calculation unit 6, and the sound pressure obtained by the calculation is input to the determination unit 10. Further, based on the output of the directional microphone 3, the power spectrum calculation unit 7 calculates the power spectrum distribution. Further, processing for subbanding the power spectrum distribution into a plurality of frequency bands is performed by the subbanding calculation unit 8, and the output is input to the determination unit 10.

  Subbanding is, for example, a process of averaging the power spectrum distribution for each fixed small range of frequencies to form a bar graph. The directional microphone 3, the sound pressure calculation unit 6, the power spectrum calculation unit 7, and the subbanding calculation unit 8 are information on sound generated by the automobile 5 (sound pressure and power spectrum distribution are subbanded. A sound information collecting unit 9A that collects (data) is configured.

  The determination unit 10 stores in advance data obtained by sub-banding an artificial sound spectrum distribution (power spectrum distribution of an artificial sound) generated by an electric vehicle. Based on the stored data, the determination unit 10 can determine whether or not the sound information collected by the sound information collection unit 9A includes an artificial sound spectrum distribution.

  FIG. 5 is a flowchart showing the processing operation of the determination unit 10. In the figure, the determination unit 10 waits until a new vehicle is sensed while repeating the determination of whether or not a new vehicle has been sensed (step S1). When sensed, the determination unit 10 determines whether or not the sound pressure level is lower than a threshold value (step S2). Here, when lower than a threshold value, it determines with a target being an electric vehicle (step S3). On the contrary, if it is more than a threshold value, the determination part 10 will determine whether there exists any artificial sound spectrum distribution (step S5). Here, the determination unit 10 determines that the vehicle is an electric vehicle if there is an artificial sound spectrum distribution (step S3), and if not, determines that the vehicle is not an electric vehicle, that is, a gasoline vehicle (step S4). . After the determination, the same processing is performed after waiting for the next vehicle detection (step S1).

In the electric vehicle identification device according to the second embodiment, in addition to the determination based on the sound pressure similar to the first embodiment, the determination unit 10 performs the determination based on the collected sound distribution as described above. Even if the electric vehicle emits artificial noise, the sound distribution (power spectrum distribution) of the electric vehicle is different from that of a gasoline vehicle or the like. Therefore, the electric vehicle can be identified from a gasoline vehicle or the like based on the sound distribution.
If all electric vehicles are required to emit artificial sounds in the future, the processing of the sound pressure calculation unit 6 in FIG. 4 and step S2 in FIG. 5 is omitted (from yes in step S1). Proceed to step S5).

  If it is necessary to distinguish between a hybrid vehicle (HEV) and an electric vehicle (EV), for example, the processing operation shown in the flowchart of FIG. 6 may be performed. The determination unit 10 in this case also stores data obtained by subbanding the engine sound spectrum distribution (typical or average engine sound power spectrum distribution) emitted by the engine. Therefore, the determination unit 10 can also determine whether or not the sound information collected by the sound information collection unit 9A includes the engine sound spectrum distribution.

  6 differs from FIG. 5 in that steps S6, S7, and S8 are provided and that step S2 in FIG. 5 is omitted, and the other steps are the same. That is, in FIG. 6, when there is an artificial sound spectrum distribution or when the sound pressure level is lower than a threshold value, the determination unit 10 determines whether or not there is an engine sound spectrum distribution (step S6).

  Here, when the engine sound spectrum distribution is present, the determination unit 10 determines that the target is HEV (step S7), and when not, determines that the target is EV (step S8). Thus, when the collected sound distribution includes both the engine sound distribution and the artificial sound distribution, the determination unit 10 determines that the collected sound is a hybrid vehicle, thereby determining a hybrid vehicle (HEV). And an electric vehicle (EV).

<Others>
Although the second embodiment focuses on the spectrum distribution (power for each subband in the processing), it is also possible to determine whether or not the vehicle is an electric vehicle simply based on the presence or absence of sound of a specific frequency. It is. That is, for example, when only the artificial sound emitted from the electric vehicle includes a sound of a specific frequency (may be an ultrasonic wave), the electric vehicle is moved from a gasoline vehicle or the like depending on whether or not the collected sound includes the frequency. It can be easily identified.

In the above-described embodiments, the automobile 5 has been described as an identification target. However, in a two-wheeled vehicle, for example, an electric motorcycle and another gasoline engine motorcycle can be distinguished from each other.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  By using the electric vehicle identification device (or identification method) as described above, for example, if an urban structure with traffic restrictions that allows only electric vehicles to pass through the gate is realized, the atmospheric environment is improved in a desired area. It becomes possible.

2: Vehicle detector 5: Automobile 9, 9A: Sound information collection unit 10: Determination unit

Claims (5)

A vehicle detector for detecting a vehicle entering the detection area;
A sound information collection unit that collects information on the sound generated by the sensed vehicle;
An electric vehicle identification apparatus comprising: a determination unit that determines whether or not the collected sound information includes a characteristic of a sound unique to the electric vehicle.   The electric vehicle identification device according to claim 1, wherein the determination unit performs determination based on the collected sound distribution.   The electric vehicle identification device according to claim 1, wherein the determination unit performs determination based on the sound pressure of the collected sound.   The electric vehicle identification device according to claim 1, wherein the determination unit performs determination based on the collected sound frequency. Detects vehicles entering the detection area,
Collect information on the sound generated by the detected vehicle,
It is determined whether or not the characteristic of the electric vehicle is included in the collected sound information. If the characteristic is included, it is an electric vehicle, and if it is not included, it is determined that the electric vehicle is not an electric vehicle. An electric vehicle identification method characterized by the above.

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