JP2001319290A - Method and device for judging vehicle kind - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly judge the kind of a vehicle passing on a road with a simple configuration. SOLUTION: The vehicle kind judging device is provided with a first detecting part 6 and a second detecting part 7 by which a vehicle passing on a road is irradiated with a laser pulse in the front and rear parts of the road in the direction crossing the road from the upper part of the vehicle with a prescribed cycle to detect the distance to the vehicle and also to detect the scanning angle. The device is also provided with an arithmetic judging part 4 where the vehicle height is calculated in a vehicle height detecting part 11 by the detection signals of the detecting parts 6 and 7, the vehicle speed is calculated from difference between passing times at the front and rear detection positions of a vehicle speed arithmetic part 12, vehicle plane parts are extracted based on vehicle height, vehicle speed and vehicle width data which are detected by a vehicle height, vehicle width and vehicle length arithmetic part 113, a roof surface deciding part 14 specifies one of the plane parts as a driver's sheet roof surface of the vehicle and a vehicle kind judging device 15 judges the vehicle kind by the height and shape of the driver's sheet roof surface, the vehicle height, the vehicle speed and vehicle width data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle type determining method and apparatus for determining a vehicle type passing through a passage.

[0002]

2. Description of the Related Art In general, a method of measuring the number of vehicles passing on a road by using an ultrasonic wave or a microwave or by taking an image by using a camera image is adopted.

[0003]

In recent years, it has become necessary to determine what kind of vehicle and how many vehicles pass on a road.

However, in the above-mentioned measuring method, there is no problem in measuring the number of vehicles passing on the road, but there is a problem that it is extremely difficult to determine the type of the vehicle. The present invention relates to a vehicle type determining method and apparatus capable of accurately determining a vehicle type with a simple configuration by solving the above problems.

[0005]

According to a first aspect of the present invention, there is provided a vehicle type determining method for irradiating a vehicle passing through a passage with a projection wave from above the vehicle in a transverse direction of the passage. The vehicle speed is calculated from the distance to the vehicle obtained by the reflected wave and the scanning angle of the projection wave, and the vehicle height and the vehicle width are calculated from the distance and the scanning angle. The vehicle length of the vehicle is calculated from the data and the speed of the vehicle, and the plane portion is extracted. One of the plane portions is specified as the ceiling surface of the driver's seat of the vehicle. The vehicle type is determined based on the length data.

According to the above configuration, the distance to the vehicle reflector is calculated by the projection wave scanned in the direction of the passage in the predetermined direction at a predetermined cycle, and the vehicle height is calculated. The vehicle height is calculated from the vehicle height data and the vehicle speed data. By extracting the length of the driver and the plane of the vehicle and identifying the driver's seat ceiling from the data of these planes, the driver's seat ceiling, which is a special feature among various types of vehicles, is identified, and the driver's seat ceiling is identified. Since the vehicle type is determined based on the data and the length of the vehicle body before and after the data, the vehicle type can be accurately determined by a simple operation.

According to a second aspect of the present invention, there is provided a vehicle type discriminating apparatus, comprising: a distance sensor that emits light; a scanning device that scans the projection light in a direction transverse to a passage at a predetermined period; and a scanning angle detection device that detects a scanning angle of the projection light. And a measuring unit having a speed detecting means for detecting the speed of the vehicle, and calculating a vehicle height and a vehicle width based on the detection signal of the distance sensor, and calculating a vehicle speed from the vehicle height data and the vehicle speed data by the speed detecting means. The length is calculated and the plane portion is extracted, and one of the plane portions is specified as the driver's seat ceiling surface, and at least the vehicle type is determined based on the driver's seat ceiling surface and the vehicle length data before and after the driver seat ceiling surface. And an operation determination unit.

According to the above arrangement, the distance to the vehicle reflection unit is measured by the projection wave scanned by the measuring unit in the direction transverse to the passage at a predetermined period. The calculation and determination unit calculates the vehicle height and the vehicle width, calculates the vehicle length from the vehicle height data and the vehicle speed data, extracts the plane part of the vehicle, and specifies the driver's seat ceiling surface from the plane parts. By this, the driver's seat ceiling surface, which is a particular feature among various types of vehicles, is determined, so that the vehicle type can be accurately determined based on the driver's seat ceiling surface data and the vehicle length data before and after the driver seat ceiling surface. The configuration makes it possible to accurately determine the vehicle type.

According to a third aspect of the present invention, in the vehicle type discriminating apparatus, the speed detecting means in the third aspect is capable of detecting the passage of a vehicle at a predetermined position in front of or behind the path of the distance sensor. An operation determination unit calculates the vehicle speed based on a detection time difference between a detection signal and / or a non-detection signal of the distance sensor and the detector and a distance between scanning positions of the distance sensor and the detector. It is constituted in.

According to the above configuration, the speed of the vehicle is detected based on the detection signals detected before and after the passage, so that the speed of the vehicle can be detected more accurately, and the length of the vehicle or the length of the plane portion can be detected. The measurement accuracy can be improved.

Further, in the vehicle type discriminating apparatus according to a fourth aspect, the detector having the above-mentioned structure is constituted by a distance sensor. According to the above configuration, the two distance sensors can determine whether or not the vehicle is a detection target, and the shape of the plane portion of the vehicle body can be calculated using an arbitrary distance sensor according to the passage conditions and installation conditions, The degree of freedom is increased, and the detection accuracy can be further improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle type discriminating apparatus according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1 to FIG. 3, this vehicle type discriminating apparatus is a passage 1 through which a vehicle 2 passes, for example, a toll gate entrance of a highway or a multi-story parking lot entrance. A measuring unit 3 for detecting a vehicle (vehicle body) 2 which is disposed on one side of the passage 1 via a single column 1a and passes therethrough; and a signal from the measuring unit 3 It comprises a calculation / determination unit 4 for determining a vehicle type, and a storage / display unit 5 including a display device 5a for displaying output data of the calculation / determination unit 4 and a storage device 5b for recording the output data.

(Measurement Unit) The measurement unit 3 includes a first detection unit 6 and a second detection unit 7 as shown in FIG. The first detection unit 6 applies a first projection light S1 composed of a laser pulse, which is a kind of a projection wave, to the vehicle 2 passing through the passage 1 from above from the ceiling surface to one side (the support 1a).
A first light emitter / receiver 21a which irradiates the side surface 5 of the first side and receives the first reflected light (reflected wave) R1 reflected on the vehicle 2 or the road surface 1b.
A first laser distance sensor 21 including a first laser distance sensor 21 that converts a detection signal of the first light emitter / receiver 21a into distance data d from the measurement unit 3 to the reflection surface of the vehicle 2 is provided. . The first emitter / receiver 21a performs laser scanning at a predetermined cycle so that the irradiation locus of the first projection light S1 intersects perpendicularly with the path (vehicle length direction A, vehicle traveling direction) on the road surface. A first scanning device 22 for performing;
A first scanning angle detector 23 for detecting the scanning angle θ ₁ of the first projection light S1 is provided.

In this embodiment, since the first detection unit 6 and the second detection unit 7 of the measurement unit 3 are installed at one place in consideration of the installation cost, the first scanning device 22 uses the first scanning unit 22. The irradiation cross section f of the projection light S1 is set so as to be inclined α ° with respect to the road surface 1b. However, the irradiation cross section f only needs to be at least a predetermined distance from the irradiation trajectory of the second detection unit 7, and the inclination angle α with respect to the road surface 1b can be corrected by the set value. May be
The first detector 6 and the second detector 7 may be separately provided.
Further, since the first detection section 1 is laser-scanned in the same manner as the second detection section 7, the detection target vehicle 2 can be detected while being distinguished from a motorcycle or the like.

Since the first detector 6 simply needs to determine the presence or absence of a vehicle, instead of a laser sensor, considering the cost of equipment, a non-proximity switch such as a proximity switch for detecting intermittent reception of projection light is used. A contact type position sensor may be used. Further, if the speed of the vehicle can be detected, the function of the first detection unit 6 can be achieved. Therefore, a speed sensor can be provided instead of the first detection unit 6.

The second detector 7 irradiates a second projection light S2 comprising a laser pulse to the ceiling surface and one (the side of the column 1a) 5 toward the vehicle 2 passing through the passage 1.
A second light emitter / receiver 31a that receives the second reflected light R2 reflected on the vehicle 2 or the road surface 1b, and converts a detection signal of the second light emitter / receiver 31a into distance data d from the measurement unit 3 to the reflection surface of the vehicle 2 A second laser sensor 31 including a second distance calculator 31b is provided. Also, the second light emitting and receiving device 31a
, The irradiation locus of the second projection light S2 intersects perpendicularly to the traveling direction of the vehicle 2, and the scanning cross section e is the road surface 1
in a predetermined cycle so as to be perpendicular to the second scanning device 32 which performs laser scan b, a second scan angle detector 33 for detecting a scanning angle theta ₂ of the second projection light S2 is provided.

(Calculation Determination Unit) The calculation determination unit 4 includes a vehicle height detection unit 11, a vehicle speed calculation unit 12, a vehicle height, vehicle width, and vehicle length calculation unit 13, a ceiling surface determination unit 14, and a vehicle type determination unit 15. Have been.

The vehicle height detecting section 11 uses the distance data d from the first and second distance calculating sections 21b and 31b and the scanning angle data θ from the scanning angle detectors 23 and 33 to measure the measuring section 3.
The height (vehicle height) h of the reflection surface of the vehicle 2 is calculated based on the set height Hs. That is, as shown in FIG. 4 (a), in the case of irradiation cross-section e is a second projection light S2 perpendicular to the road surface 1b is obtained by the vehicle height _{h 2 = Hs-d 2 ×} cosθ 2. However, as shown in FIG. 4B, the first projection light S1 has an irradiation cross section f inclined by α ゜ with respect to the road surface,
In this case, the detected distance data d ₁ is stored in the path 1
Is corrected to the distance data d ₁ ′ on the vertical coordinate plane in the length direction, d ₁ ′ = d ₁ × cos θ ₁ , and the actual vehicle height h ₂ =
Hs−d ₁ ′ × sin α = Hs−d ₁ × cos θ ₁ × sin α. Then, the calculation results for the plurality of scans are stored in a memory (not shown).

The vehicle speed calculation unit 12 calculates the distance between the front ends of the vehicle 2, that is, the horizontal distance between the positions where the vehicle is first detected by the first projection light S1 and the second projection light S2 (the first projection light S
1 position correction) Ls by detecting the height h _1, the first time difference when detecting the vehicle (when detecting the high height h from the road surface) by the first projection light S1 and the second projected light S2 (actually Is obtained by dividing by the number of scans × scan cycle) to obtain first vehicle speed data of the vehicle 2. Further, the distance between the rear ends of the vehicle 2, that is, the horizontal distance between the positions where the vehicle is finally detected by the first projection light S1 and the second projection light S2 (the first projection light S
1 is corrected by the detection height h ₁ ).
1 and the second projection light S2, the vehicle is finally detected (only the road surface can be detected), and the time difference (actually, the time determined by the number of scans and the scan cycle) is divided. Second vehicle speed data is obtained. Then, the speed V of the vehicle 2 is determined by taking an average value of the first vehicle speed and the second vehicle speed or selecting one of the first vehicle speed and the second vehicle speed depending on the measurement environment, setting conditions, and the like. I do.

As another speed detection method in the vehicle speed calculation unit 12, the scan cycle is shortened and fine measurement is performed.
When calculating the vehicle speed at the front end of the vehicle 2, among the data in several scans near the front end, if the horizontal distance is obtained between the positions where the heights h1 and h2 of the first projection light S1 and the second projection light S2 are close. Good. The concept is the same when calculating the vehicle speed at the rear end of the vehicle 2.

Further, the vehicle height / vehicle / vehicle length calculation unit 13 calculates the amount of movement (length) of the vehicle 2 between predetermined scanning timings based on the vehicle speed and the scanning timing of the second projection light S2, and calculates the vehicle length L =
It is calculated from the number of scans × scan cycle × vehicle speed V. As the vehicle height, the highest value is selected from the vehicle height data h. Further, the vehicle width D is, as shown in FIG.
In each irradiation cross section, the distance data at the left end higher than the road surface is d _L , the scanning angle at that time is θ _L, and the distance data at the right end higher than the road surface is d _R , the scanning angle at that time is θ _R , and the vehicle width D =
| D _L × cos θ _L −d _R × cos θ _R |

The ceiling surface determination unit 14 determines that the height of the plane portion of the vehicle 2 calculated based on the vehicle height data h is within a predetermined range and that the height is equal to or greater than a predetermined value. ,
The length along the vehicle length direction A is equal to or more than a certain value, and the plane portion closest to the front surface of the vehicle 2 is specified as the driver's seat ceiling surface 2a.

That is, whether or not the ceiling surface is a plane portion is first determined from the height data h of the vehicle 2 by a plurality of scans calculated by the vehicle height detection unit 11 in the vehicle length direction as shown in FIG. Data and width data,
A plane portion satisfying the formula is searched for from the front side of the vehicle 2 in order.

| H (I, j) -H (I, j + 1) | <TH where I: row (vehicle height data h in the vehicle length direction) j: column (vehicle height data in the vehicle width direction) h) H (I, j): Vehicle height data h on the I-th row and j-th column, H (I, j + 1): Vehicle height data h on the I-th row and j + 1-th column, TH (Threshold): It is regarded as a plane Range (threshold) for the height difference.

Here, as shown in FIG.
It is conceivable that a value equal to the distance data d ₁ and d ₂ appears on the side surface 2b, but in the case of the side surface, | H (I, j) −H (I, j + 1) |
Since TH is satisfied, the above expression is not satisfied, and it can be determined whether the surface is the ceiling surface or the side surface.

When a data string that satisfies the above equation at a certain ratio or more is found, it is checked whether or not this plane portion satisfies the equation. TH Min <| Hv (I) −Hv (I + 1) | <TH Max... TH Min: Minimum allowable value of height difference between adjacent measurement points TH Max: Maximum allowable value of height difference between adjacent measurement points Hv ( I): Average value of vehicle height data h on line I Hv (I + 1): Average value of vehicle height data h on line I + 1. Thus, a plane portion satisfying the above expression and the expression is extracted as a plane portion.

Then, it is calculated whether the height is at least one fixed value and the length in the vehicle length direction is not less than a certain value, and the vehicle 2 among the flat portions satisfying these conditions is calculated. Is identified as the driver's seat ceiling surface 2a.

The vehicle type discriminating unit 15 discriminates the vehicle type based on the vehicle type data input in advance, based on the calculation result of the ceiling surface determining unit 14 and the data obtained by the vehicle height / width / vehicle length calculating unit 13. I do.

For example, as one criterion, FIG.
As shown in FIG. 14, a hood portion and a trunk portion of predetermined vehicle lengths L1 and L3 are provided at front and rear portions of a driver's seat ceiling surface 2a. The value of the plane portion of each of these vehicle types has a different threshold value depending on the vehicle type, and the range of the vehicle length is also determined by the vehicle type. Further, except for the driver's seat ceiling surface 2a that does not satisfy the above and the formula, the ceiling surface determination unit 1
In 4, the lengths L1, L3 and height h of the front body and the rear body behind the driver's seat ceiling surface 2a are calculated, and the length data L1 of the front body, the driver's seat ceiling surface 2a and the rear body are calculated. , L2, L3, the vehicle type is determined. In addition,
The vehicle type is similarly determined for the vehicle 2 (body) shown in FIG. 12 (one-box type), FIG. 9 (truck), and FIG. 13 (bus).

Here, depending on the vehicle type, the driver's seat ceiling surface 2
In some cases, a is provided with a sunroof S that does not reflect a laser pulse, but in this case, the vehicle height data h is disturbed. Therefore, as shown in FIG. 15, a row of points indicating the maximum height among the vehicle height data h (measurement data row) is connected and regarded as a straight line (straight line approximation processing), and the slope S ( 1,2,
Among the points (3, 4), the part where the vehicle height data h is disturbed is a straight line and a gradient, that is, S (3) in the figure satisfies the following expression: TH Min <S (3) <TH Max. In this case, the ceiling surface determination unit 2a determines that portion as the sunroof S. Thus, according to this embodiment, it is possible to specify the vehicle type regardless of the presence or absence of the sunroof.

Next, a vehicle type discriminating method in the vehicle type discriminating apparatus having the above configuration will be described with reference to flowcharts of FIGS. 1. As shown in FIG.
1a and the first projection light S1 and the second projection light S2 are respectively radiated from the second projection / reception device 31a toward the passage 1,
The first reflected light R1 and the second reflected light R2 are detected. These detection signals are used as the first and second distance calculation units 21b and 3b.
In step 1b, a distance d from the measuring unit 3 to the reflection surface of the vehicle 2 is calculated.

This operation is performed by the first light emitter / receiver 21 and the second light emitter / receiver 31 until one line scan is completed, and the distance data for one line is sequentially stored in the distance calculators 24 and 34.

Next, as shown in FIG.
Then, detection signals from the first and second distance calculation units 21a and 31a and the first and second scanning angle detectors 23 and 33 are input, height data h is calculated from these data, and stored in the memory. .

In detecting the front end of the vehicle, the second
The height data h ₂ from the detector 7 is checked, the road surface 1
When a portion higher than b (= vehicle) is detected, the height data h ₂ is output to the vehicle speed calculator 12. Then, the checked height data h ₁ of the first detector 6 of the vehicle height detecting unit 11, is higher than the road surface 1b part (= vehicle) is detected,
Height data h ₁ is stored in the memory is output to the vehicle speed calculating unit 12. Similarly, the rear end of the vehicle is detected.

The vehicle speed calculator 12 calculates the vehicle speed based on the horizontal distance between the front and rear ends of the vehicle 2 by the first and second projection lights S1 and S2 and the detection time difference by the first and second projection lights S1 and S2. 2 speed V is determined.

Further, as shown in FIG.
The vehicle length calculating unit 13 calculates the vehicle height h, the vehicle length L, and the vehicle width D of the vehicle 2 based on the detection data of the second detecting unit 7. Next, the ceiling surface determination unit 14 determines that the height is 1 based on the height data h.
The driver's seat ceiling surface 2a is determined to be a portion that is equal to or more than a fixed value, is equal to or more than one fixed value in a plane along the length direction of the vehicle length, and is closest to the front surface of the vehicle 2.

Subsequently, in the vehicle type discriminating section 15, the length L1 of the front vehicle body and the length L3 of the rear vehicle body on the driver's seat ceiling surface 2a are determined.
Is calculated, and the vehicle type is determined from the data of the vehicle length, the vehicle height, and the vehicle width and L1, L2, and L3 of the vehicle body.

As described above, according to the above-mentioned embodiment, the driver's seat ceiling is specified by detecting the flat part, which is a feature of the vehicle type discrimination, and the data of the height, width and length of the driver's seat ceiling, The position of the seat ceiling (including the front and rear hoods and trunks) is taken into account, and the vehicle type can be accurately specified from the data of the vehicle height, width, and length.

Further, by simply scanning the two laser distance sensors, it is possible to extract the required plane portion of the vehicle and specify the driver's seat plane portion, thereby simplifying the device structure.
It can be provided at low cost. Thus, for example, in a preliminary investigation such as a road plan, it is possible to automatically investigate what kind of vehicle has a certain amount of traffic and to effectively use the road plan.

In the above embodiment, a laser distance sensor is used as the distance sensor, but an ultrasonic distance sensor may be used.

[0042]

As described above, according to the vehicle type discriminating method according to the first aspect, the distance to the vehicle reflecting portion is obtained by calculating the vehicle height by using the projection wave scanned in the transverse direction of the passage at a predetermined cycle. By extracting the vehicle length and the plane portion of the vehicle from the vehicle height data and the vehicle speed data, and specifying the driver's seat ceiling surface from the data of these plane portions, the driver's seat ceiling, which is a special feature among various types of vehicles, is provided. Since the surface is specified, and the vehicle type is determined based on the height, shape, and position of the driver's seat ceiling surface and the vehicle length data before and after it, the vehicle type can be accurately determined by a simple operation.

According to the vehicle type discriminating apparatus of the second aspect, the measuring unit measures the distance to the vehicle reflecting unit by using a projection wave that is scanned in the transverse direction of the passage at a predetermined cycle. The calculation and determination unit calculates the vehicle height and the vehicle width, calculates the vehicle length from the vehicle height data and the vehicle speed data, extracts the plane part of the vehicle, and specifies the driver's seat ceiling surface from the plane parts. By this, the driver's seat ceiling surface, which is a special feature among various types of vehicles, is determined, so that the vehicle type can be accurately determined based on the driver's seat ceiling surface and vehicle length data before and after the driver's seat ceiling surface. The vehicle type can be accurately determined.

According to the vehicle type discriminating device of the third aspect, the speed of the vehicle is detected based on the detection signals detected before and after the passage, so that the speed of the vehicle can be detected more accurately. The measurement accuracy of the vehicle length and the length of the flat portion can be improved.

Further, according to the vehicle type discriminating device of the fourth aspect, it is possible to determine whether the vehicle is a detection target vehicle by using two distance sensors, and to use a vehicle body using an arbitrary distance sensor according to a passage situation and installation conditions. Can be calculated, the degree of freedom can be increased, and the detection accuracy can be further improved.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing an embodiment of a vehicle type identification device according to the present invention.

FIG. 2A is a cross-sectional view of a vehicle showing a detection state of the same vehicle type identification device, and FIG. 2B is a front view showing a detection state of the same vehicle width.

FIG. 3 is a configuration diagram showing the vehicle type identification device.

4 (a) and 4 (b) show a method of calculating vehicle height data by the vehicle type discriminating apparatus, FIG. 4 (a) is an explanatory diagram of a second reflected light,
(B) is an explanatory diagram of the first reflected light.

FIG. 5 is an overall schematic diagram showing a detection state by the same vehicle type identification device.

FIG. 6 is a schematic side view showing a detection state of the vehicle type identification device.

FIG. 7 is a flowchart illustrating a determination procedure of the vehicle type determination apparatus.

FIG. 8 is a flowchart illustrating a determination procedure of the vehicle type determination apparatus.

FIG. 9 is a flowchart illustrating a determination procedure of the vehicle type determination apparatus.

FIG. 10 is an explanatory view showing a vehicle body of a sedan type determination reference by the vehicle type determination device.

FIG. 11 is an explanatory diagram showing a vehicle body as a van type determination reference by the vehicle type determination device.

FIG. 12 is an explanatory diagram showing a vehicle body of a one-box type determination reference by the vehicle type determination device.

FIG. 13 is an explanatory diagram showing a vehicle body as a reference for discriminating a truck type by the vehicle type discriminating apparatus.

FIG. 14 is an explanatory diagram showing a vehicle body as a reference for determining a bus type by the vehicle type determination apparatus.

FIG. 15 is an explanatory diagram showing a determination state of a vehicle body having a sunroof by the vehicle type determination device.

[Explanation of symbols]

 S1, S2 First and second projection light R1, R2 First and second reflected light 1 Passage 1a Support 1b Road surface 2 Body 3 Measuring unit 4 Calculation determining unit 5 Storage display unit 6 First detecting unit 7 Second detecting unit 11 Vehicle height detecting section 12 Speed calculating section 13 Vehicle height / vehicle width / vehicle length calculating section 14 Ceiling surface determining section 15 Vehicle type determining section 21 First laser distance sensor 21a First light emitting / receiving device 21b First distance calculating section 22 First scanning Apparatus 23 First scanning angle detector 31 Second laser distance sensor 31a Second light emitter / receiver 31b Second distance calculator 32 Second scanning device 33 Second scanning angle detector

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Claims (4)

[Claims] A vehicle passing through a passage is irradiated with a projection wave from above the vehicle to scan the vehicle in a direction transverse to the passage at a predetermined period, and the distance to the vehicle obtained by the reflected wave and the projection wave. The vehicle speed is obtained from the scanning angle, the vehicle height and the vehicle width are calculated from the distance and the scanning angle, the vehicle length of the vehicle is calculated from the vehicle height data and the vehicle speed, and the plane portion is extracted. A vehicle type discriminating method characterized in that one of the parts is specified as a driver's seat ceiling surface of a vehicle, and a vehicle type is determined based on at least the driver's seat ceiling surface and vehicle length data before and after the driver seat ceiling surface. 2. A distance sensor for irradiating a vehicle passing through a passage with a projection wave from above the vehicle to detect a distance to the vehicle, and a scanning device for scanning the projection light in a transverse direction of the passage at a predetermined period. A scanning angle detector for detecting a scanning angle of the projection light, a measuring unit having a speed detecting means for detecting a speed of the vehicle, and calculating a vehicle height and a vehicle width based on a detection signal of the distance sensor, The vehicle length is calculated from the vehicle height data and the vehicle speed data by the speed detecting means, and a plane portion is extracted. One of the plane portions is specified as a driver's seat ceiling surface, and at least the driver's seat ceiling surface is determined. A vehicle type discriminating device comprising: a calculation determining unit that determines a vehicle type based on data on vehicle lengths before and after the vehicle length. 3. The speed detecting means comprises the distance sensor and a detector arranged to detect the passage of a vehicle at a predetermined position in front of or behind the path of the distance sensor. 3. The vehicle type discrimination according to claim 2, wherein a vehicle speed is calculated based on a detection time difference between a detection signal and / or a non-detection signal of the detector and a horizontal distance between a position detected by the distance sensor and the detector. apparatus. 4. A vehicle type discriminating apparatus according to claim 2, wherein said detector comprises a distance sensor.