JPH0228799A - Kind of vehicle discriminating device - Google Patents

Abstract

PURPOSE:To surely discriminate the kind of a vehicle through comparatively simple constitution by obtaining a picture to show the temperature distribution of a passing vehicle by combining a strip-shaped heater, an infrared ray sensor and an outside air temperature sensor. CONSTITUTION:When the vehicle 6 passes on a road 8, detection data from the vehicle 6 and the strip-shaped heater 2 detected by the infrared ray sensors 4a, 4b is fetched in a control unit 16 by time division system. In this case, since the unit 16 controls the input levels of the heater 2 and the sensors 4a, 4b according to the detection data of the outside air temperature sensor 12, the overall temperature of a car body is different from the reference temperature of the heater 2. Therefore, the picture to show the temperature distribution of the passing car 6 based on the background of the temperature of the heater 2 is obtained by this temperature. This picture includes not only the contour of the vehicle 6 but the picture of an engine and a driver, etc., mounted on the vehicle. Accordingly, the kind of the vehicle can be discriminated by extracting the feature of the vehicle like the length and the width of the vehicle, the position of the engine, the number of axles, etc., on based the basis of this picture.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a vehicle type discrimination device.

<Prior Art> At expressway toll gates, etc., it is sometimes necessary to determine the number of vehicles passing and the type of vehicle.

Conventionally, there are various types of vehicle detectors, such as a loop coil type, an ultrasonic type, and a light beam type. However, these vehicle detectors only detect whether or not a vehicle is passing, but cannot determine the type of vehicle.

Conventionally, devices for identifying vehicle types have a resistance contact and a flat contact buried in the road surface, and the wheel width is determined based on the change in resistance value of the resistance contact as the vehicle passes, and the on/off change of the flat contact is detected. There is a system that detects the number of wheels based on the number of wheels.

Further, as another vehicle type discrimination device, there is one that captures an image of a vehicle using a COD camera and discriminates the vehicle type based on the image data.

<Problems to be Solved by the Invention> However, in the former device, the contact points are pressurized every time a vehicle passes by, so they lack durability.

Furthermore, in order to identify special vehicles such as pole trailers and towing vehicles, additional auxiliary means are required, resulting in increased costs.

Furthermore, the latter device has drawbacks such as not only is it time consuming to cut out the image, but also the entire device is large-scale.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle type identification device that can reliably identify vehicle types with a relatively simple configuration and has excellent durability. shall be.

<Means for Solving the Problems> In order to achieve the above object, the present invention adopts the following configuration.

That is, the vehicle type discrimination device of the present invention is arranged opposite to a band-shaped heating element installed on a road surface perpendicular to the vehicle passing direction, above both sides of the road surface and including the band-shaped heating element within the detection field of view. A pair of infrared sensors, an outside temperature sensor arranged near these infrared sensors to detect outside temperature, and control of the input level of the strip heating element and each infrared sensor based on the detection output from the outside temperature sensor. The apparatus also includes a control unit that captures detection data from the infrared sensor as image data in a time-division manner.

<Operation> According to the above configuration, when the vehicle passes through the road, the detection data from the vehicle and the band-shaped heating element detected by the infrared sensor is captured in the control unit in a time-sharing manner. At that time, the control unit controls the input level of the strip heating element and the infrared sensor based on the detection output of the outside temperature sensor.
The overall temperature of the vehicle body is different from the reference temperature of the strip heating element.

Therefore, based on this temperature difference, an image showing the temperature distribution of the passing vehicle with the temperature of the band-shaped heating element as the background can be obtained. This image includes not only the outline of the vehicle but also images of the engine installed in the vehicle, the driver, etc. Therefore, based on this image, vehicle characteristics such as vehicle length, vehicle width, engine position, and number of axles can be extracted to determine the vehicle type.

<Example> FIG. 1 is a perspective view showing the arrangement of a vehicle type discrimination device.

In the figure, ■ indicates the entire vehicle type identification device, 2 is a band-shaped heating element, 4a and 4b are a pair of pyroelectric infrared sensors,
6 is a passing vehicle. Then, the belt-shaped heating element 2 is connected to the road surface 8
Each infrared sensor 4a is installed on the top perpendicular to the vehicle passing direction.

4b are pillars 10a, 1 erected on both sides of the road surface 8 so as to hang down the lower part of the passing vehicle 6 and the band-shaped heating element 2.
A band-shaped heating element 2 is disposed on the upper part of 0b so as to be included in the detection field of view and facing each other. Reference numeral 12 denotes an outside temperature sensor that detects the outside temperature, and is attached to one of the pillars 10a at a position close to the infrared sensor 4a. Reference numeral 14 denotes a toll gate building, and in this building 14, the input levels of the band-shaped heating element 2 and each infrared sensor 4a, 4b are controlled based on the detection output from the outside temperature sensor 12, and the infrared sensors 4a, 4. b
A control unit 6 is arranged to take in the detection data from the image data as image data in a time-sharing manner.

FIG. 2 is a block diagram of the control unit.

In the figure, 20 is a timing generator that outputs a timing pulse that takes in the detection outputs of infrared sensors 4a and 4b in a time-division manner, and 22a and 22b are infrared sensors 4.
a, a process amplifier that amplifies the detection output from 4b, 2
4a and 24b are A/D converters that digitize the detection output that has passed through the process amplifier. And an infrared sensor 4a.

The output timing of 4b and the A/D conversion timing are synchronized by timing pulses from the timing generator 20. 26a and 26b are preprocessing circuits that adjust the quantization level of the digitized detection output to remove noise components, 28 is a level setter that sets the quantization level of each preprocessing circuit 26a and 26b, and 30a and 30b are This is a frame memory that stores the detection data that has passed through the preprocessing circuits 26a and 26b as image data. 32a, 32
b is a ■10 processor that extracts vehicle characteristics such as vehicle length, vehicle width, engine position, and number of axles of a passing vehicle based on the image data stored in each frame memory 30a and 30b; 34 is an I10 processor that extracts characteristics of a passing vehicle; Main CPU that determines the vehicle type based on extracted vehicle data
It is. Further, 36 is a main common memory that stores vehicle data, 38 is a heating element control section that controls the heat generation temperature of the band-shaped heating element 2 based on the detection output from the outside temperature sensor 12, and 40 is an interface.

Next, the vehicle type discriminating operation of the vehicle type discriminating device I having the above configuration will be explained.

The detection outputs from the infrared sensors 4a and 4b are taken in in a time-division manner by timing pulses from the timing generator 20 of the control unit 16.

When no vehicle passes, only the infrared rays emitted from the band-shaped heating element 2 are detected by the infrared sensors 4a and 4b.

On the other hand, when the vehicle 6 passes over the band-shaped heating element 2, the infrared rays from the vehicle 6 and the band-shaped heating element 2 are both transmitted to the infrared sensor 4a.
, 4b.

Moreover, in this case, since vehicles slow down near the toll plaza building in order to pay tolls, the passing speed of the vehicles remains almost constant without much difference. The control unit 16 also controls the infrared sensors 4a and 4b based on the detection output of the outside temperature sensor 12.
, and also controls the heat generation temperature of the band-shaped heating element 2.

Therefore, if the infrared sensors 4a and 4b detect the infrared rays emitted from the vehicle 6 and the strip heating element 2, the overall temperature of the vehicle body will be different from the reference temperature of the strip heating element. Therefore, if the detection outputs of the infrared sensors 4a and 4b are written to the frame memories 30a and 30b, an image showing the temperature distribution of the passing vehicle with the temperature of the band-shaped heating element as a background due to the temperature difference between the vehicle 6 and the band-shaped heating element 2 is created. can get. This image includes not only the outline of the vehicle but also images of the engine installed in the vehicle, the driver, etc.

The I10 processors 32a, 32b extract vehicle characteristics such as vehicle length, vehicle width, engine position, and number of axles based on the image data stored in each frame memory 30a, 30b. For example, if an image of a vehicle as shown in FIGS. 3(a) to 3(C) is obtained, the length of the vehicle can be determined from the outline of the image. , Ll, L2 and the number of axles. Furthermore, since the temperature of the engine is high, the gradation level of the image is different from that of the surroundings. Therefore, the engine position can be checked. Since the driver's body temperature is different from the vehicle body temperature, it is also possible to check the position of the driver's seat. Furthermore, as shown in FIGS. 4(a) and 4(b), for both images based on the detection outputs of the respective infrared sensors 4a and 4b, the distance M from the bottom to the wheel position. ，
By measuring M, the installation interval, installation height, elevation angle, etc. of the infrared sensors 4a and 4b are known in advance, so the vehicle width can be calculated from these values.

Next, the main CPU 34 includes an I10 processor 32a,
Based on the above-mentioned data such as vehicle length, vehicle width, engine position, and number of axles extracted in step 32b, the vehicle type is determined according to the flowchart shown in FIG. 5, for example.

<Effects of the Invention> According to the present invention, an image showing the temperature distribution of a passing vehicle with the reference temperature of the band-shaped heating element as the background can be obtained based on the detection output from the temperature sensor. Therefore, the vehicle type can be reliably determined based on this image. Moreover, excellent effects such as excellent durability are exhibited.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the arrangement of the vehicle type identification device, Fig. 2 is a block diagram of the control unit of the device, Fig. 3 is an explanatory diagram for extracting vehicle characteristics from an image, and Fig. 4 is an image FIG. 5 is a flowchart showing an example of determining the vehicle type based on vehicle data from which characteristics have been extracted. 1... Vehicle type identification device, 2... Band-shaped heating element, 4a14
b... Infrared sensor, 6... Vehicle, 12 - Outside temperature sensor, 16... Control unit. Applicant Furuno Electric Co., Ltd. Agent Patent Attorney Oka 1) Kazuhide Diagram Diagram

Claims (1)

[Claims] (1) A band-shaped heating element installed on the road surface perpendicular to the vehicle passing direction; a pair of infrared sensors arranged opposite to each other above both sides of the road surface and including the band-shaped heating element within the detection field of view; an outside temperature sensor arranged near the infrared sensor to detect the outside temperature; and an outside temperature sensor that controls the input level of the strip heating element and each infrared sensor based on the detection output from the outside temperature sensor, and A vehicle type discrimination device comprising: a control unit that captures detection data of as image data in a time-sharing manner;