JPS5827557B2 - Vehicle type identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle type identification device for vehicles running on a road surface.

Various devices of this kind have been proposed in the past, but for those that use light beams or ultrasonic waves, the photoelectric switch and ultrasonic head must be installed in the appropriate location with accurate orientation. Therefore, it is difficult to easily install or move it anytime and anywhere.

There are also some that use loop coils, but these simply classify vehicle lengths based on the length of time the vehicle exists.

In addition, conventional methods generally use the vehicle length,
Vehicle height, vehicle width, etc. are used.

Discrimination based on vehicle length can only distinguish between two types, large and small, and it is impossible to distinguish between passenger cars and trucks, which have similar vehicle lengths.

In addition, discrimination based on vehicle height has a high possibility of incorrect discrimination because even if the vehicle is of the same type, the vehicle height varies greatly depending on the presence or absence of cargo.

Furthermore, it is relatively difficult to determine vehicle width by measuring vehicle width.
Moreover, it is impossible to distinguish between a passenger car and a truck, which have similar vehicle widths.

As described above, none of the conventional discrimination elements are appropriate, and therefore the discrimination accuracy is low and only insufficient discrimination can be performed.

It is an object of the present invention to eliminate the drawbacks of the conventional devices described above, and to provide a vehicle type discrimination device that can be easily installed on a road surface at any location in a short time and can discriminate the vehicle type with high accuracy. .

The present invention will be described with reference to embodiments shown in the drawings.

Fig. 1 shows a vehicle type discrimination device 1, 2 is a loop coil fixedly installed on the road surface 3 (for one lane) on which the vehicle travels with adhesive tape 4, etc., and 5 and 6 are loops in the direction of travel of the vehicle as shown by arrows. These loop coils 2 and load sensors 5 and 6 are load sensors fixedly installed on the road surface 3 with adhesive tape 4 or the like in front and behind the coil 2, respectively.
is designed to be covered by one vehicle as a unit.

7 is a vehicle detector connected to the loop coil 2; 8.9 is an axle detector connected to each of the load sensors 5 and 6; 1;
0 is a discrimination classification totalizer connected to the vehicle detector 7 and the axle detectors 8 and 9.

The loop coil 2 may be wound once, but it is preferable to wind it multiple times (for example, three times) from the viewpoint of sensitivity, and instead of being attached to the road surface 3, it may be embedded in the road surface 3.

The load sensors 5 and 6 may be a foot switch made of two metal plates whose contacts are closed when the wheels of the vehicle run over the vehicle, or any other suitable device may be used.

Furthermore, the installation positions of the load sensors 5 and 6 are not limited to the above-mentioned ones. Alternatively, the load sensor 5 may be placed behind the loop coil 2, and the load sensor 6 may be placed further behind the load sensor 5.

The vehicle detector 7 supplies an alternating current (preferably a high frequency current) to the loop coil 2 and outputs a voltage corresponding to the variation in the inductance of the loop coil 2 which changes when a vehicle passes over the loop coil 2. It can be constructed using appropriate electrical means.

The axle detectors 8 and 9 generate an output when the vehicle wheels pass over the load sensors 5 and 6, for example, when the foot switch is turned on, and can be configured by appropriate electrical means. .

The discrimination classification tabulator 10 receives the output of the vehicle detector 7, and
It outputs the length of the vehicle, the pattern diagram showing the ground clearance, and the peak value showing the minimum ground clearance of the vehicle as shown in Figures 2 and 3, and also receives the outputs of both axle detectors 8 and 9. , which calculates the number of axles of a vehicle, the distance between axles, etc. based on a timing chart as shown in Fig. 4, and can be constructed by combining appropriate electrical means and output equipment such as a recorder. .

Comparing the pattern diagram of a passenger car shown in Figure 2 with the pattern diagram of a large truck shown in Figure 3, it is found that passenger cars have a short vehicle length, and the bottom surface of the axle and other parts, which generally have minimum ground clearance, is Since the truck is flat and has a low height d from the road surface, a high and short pattern with a nearly flat top can be obtained as shown in Figure 2, and large trucks have a long vehicle length.
In addition, since the bottom surface of the other parts is higher than the axle part and the height D from the road surface is higher overall, a pattern diagram having a low and long top part at each axle part as shown in FIG. 3 can be obtained.

Therefore, by examining such pattern diagrams for each vehicle type in advance, storing multiple basic pattern diagrams for each vehicle type in an appropriate internal device, and comparing the pattern diagrams obtained from the running vehicle with the basic pattern diagrams, the vehicle type can be determined. The discrimination classification tabulator 10 is configured in this way.

In addition, the peak value H of the pattern waveform as shown in Figures 2 and 3
The type of car can also be determined by the size of the car.

In principle, the peak value can be used as a sufficient discriminating factor as it is, but if the measurement point is moved, the reference level may change and the level of the peak value may change accordingly.

Therefore, before starting measurement, a metal plate of a predetermined size is placed at a predetermined height above the loop coil 2 installed at the measurement point, and the output voltage of the loop coil 2 by this metal plate is set as the reference level B. Keep this loop coil 2
The ratio of the peak value H obtained by passing the vehicle over the reference level B (hereinafter referred to as a coefficient, coefficient - 1) is determined.

An example of this is as follows.

Therefore, the vehicle type can be determined by storing a plurality of standard coefficients for each vehicle type in an appropriate internal device, converting the peak value obtained from the running vehicle into a coefficient, and comparing it with the standard coefficient. The discriminant classification totalizer 10 is configured in this way.

Further, the type of vehicle can also be determined based on the number of axles, the distance between axles, etc. obtained from a timing chart as shown in FIG.

That is, the size of a vehicle is generally proportional to the distance between its axles, and vehicles with three or more axles are vehicle types with large dead weights and large loaded weights, such as large trucks or trailer trucks.

The number of axles and the distance between axles are calculated as follows.

Therefore, by calculating the number of axles, the distance between axles, etc. in this manner, the type of vehicle can be determined, and the discrimination classification totalizer 10 is configured to perform calculations for this calculation.

When using the vehicle type identification device 1 as described above, a measurement point is arbitrarily selected and the loop coil 2 and load sensors 5, 6 are placed on the road surface 3 at a measuring point, for example, depending on the width of the loop coil 2, that is, the front part and the rear part. The distance between the front part of the loop coil 2 and the load sensor 5 is 10C7rL.
, the rear portion of the loop coil 2 and the load sensor 6 are fixedly installed so that the distance between them is 30c111, and furthermore, a reference level to be used for the coefficient ratio of the peak value is set.

When a traveling vehicle is measured in this manner, the pattern diagram, peak value, coefficient, number of axles, distance between axles, etc. are obtained, and by making a comprehensive judgment on these, the type of the traveling vehicle can be determined with high accuracy. The Rukoto.

This invention is as described above, and includes a loop coil and two load sensors on the road surface on which the vehicle is running, which are located one after the other with respect to the running direction of the vehicle, and which are covered as a unit within a range covered by one vehicle. It is only necessary to install the loop coil, etc., and there is no need to set the loop coil etc. in the correct direction when installing it, so it is possible to arbitrarily select a measurement point and install it on the road surface in a short time. It hardly impairs the natural flow of the flow.

In addition, the vehicle detector is equipped with multiple basic pattern diagrams that correspond to each vehicle type and calculate the vehicle length and ground clearance, and multiple standard coefficients that are calculated from the ratio of the peak value calculated from the minimum ground clearance of the vehicle to the standard level. A discrimination classification tabulation device set in advance in the internal device is connected and provided, and an axle detector is connected in parallel to the discrimination classification tabulation device so that the counting device can calculate the number of axles of the vehicle and the distance between axles. , the discrimination classification totalizer receives the output of the vehicle detector and outputs a coefficient obtained from the pattern diagram and the ratio of the peak value to the reference level, and also receives the output of the axle detector and outputs a coefficient determined from the pattern diagram and the ratio of the peak value to the reference level. number,
The system is configured to calculate the distance between the axles, and to determine the type of the traveling vehicle based on the calculated value and a comparison between the pattern diagram and coefficients based on the output and the basic pattern diagram and standard coefficients. Compared to conventional methods that use a loop coil to determine the length of the vehicle, there are many differentiating factors, and the type of vehicle being traveled can be determined with high accuracy.
Therefore, it has excellent effects such as being able to provide extremely useful information for analyzing sources of noise, vibration, etc., and for road maintenance and management.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIGS. 2-3 are diagrams showing the output of the discriminative classification aggregator, and FIG. 4 is a timing chart. 1... Vehicle type identification device, 2... Loop coil, 5, 6
...Load sensor, 7...Vehicle detector, 8,9...
Axle detector, 10...discrimination classification totalizer.

Claims (1)

[Claims] 1 A loop coil and two load sensors are placed on the road surface on which the vehicle is running, and they are located one behind the other with respect to the vehicle's running direction.
and installed as a unit within a range covered by one vehicle, applying an alternating current to the loop coil, and responding to fluctuations in inductance of the loop coil that changes when a vehicle passes over the loop coil. A vehicle detector that outputs a voltage corresponding to the load sensor is connected to the vehicle detector, and each of the load sensors is connected to an axle detector that generates an output when a wheel of the vehicle passes over each load sensor. The detector is equipped with multiple basic pattern diagrams that correspond to each vehicle model, including vehicle length and ground clearance, and multiple standard coefficients that are determined from the ratio of the peak value of the vehicle's minimum ground clearance to the reference level. A discrimination classification totalizer set in the internal device is connected and provided, and the axle detector is connected in parallel to the discrimination classification totalizer so that the totalizer can calculate the number of axles of the vehicle and the distance between axles. , the discrimination classification tabulator receives the output of the vehicle detector and outputs a coefficient obtained from the pattern diagram and the ratio of the peak value to the reference level, and also receives the output of the axle detector and outputs a coefficient determined from the pattern diagram and the ratio of the peak value to the reference level. , the distance between the axles is calculated, and the model of the traveling vehicle is determined based on the calculated value and a comparison between the pattern diagram and coefficients based on the output and the basic pattern diagram and standard coefficients. A vehicle type identification device featuring: