DE1294725B - Arrangement for classified counting of vehicles on traffic routes - Google Patents

Description

1 2

The invention relates to an arrangement for the classic with it is possible to increase the number of photodiodes and

fied counting of vehicles according to their height. Double counts that result

using a transmitter, which has a narrow, arise that part of the structures z. B. one

sharply delimited radiation sphere of the intensity-modulated truck reflected from the same height as the

Emits light, and a receiver for the 5 body of a passenger car or the

Conversion and reinforcement of the roadway or street level, can be z. B. eliminate it,

Vehicle reflected light signals. that with electrical or mechanical means the

The problem of vehicles on traffic routes due to reflections on the low surfaces of a vehicle

counting is relatively easy to solve. Except for trucks or on the road

Radar systems and ultrasonic detectors come io counting is reversed when a

for this purpose, among other things, infrared detectors are considered. Counting process by reflecting surfaces from large

But if it is a question of vehicles not only triggered at great heights.

count, but also classify, e.g. B. The arrangement of the invention is as follows

Passenger cars and trucks separately on the basis of the drawing for an embodiment

register, certain difficulties arise; 15 explained in more detail.

Radar detectors on the one hand are very complex and in the drawing, N is the roadway z. B. can, because it denotes a main road because of the use of the Doppler, on which effect for speed measurement with horizontal perpendicular to the plane of the drawing vehicles of different valley or oblique to the roadway type - trucks and passenger cars - have to work and also in contrast to so like to move, the different heights of which are indicated by a bundled light beam that is quite broad, the height dimensions h _t and h ₂ . Having a cone of rays, classify vehicles only according to a radiation source located above the lane 5 dimension, which different sizes, how is forth on the lane via a LmSeL ₁ and z. B. vehicle length, vehicle height, beam width an infrared filter F contains an audio-frequency modulated light, etc., which, however, is not directed to the driving beam, which is on the lane in the points, tool dimensions in detail, i.e. according to length or on a passing passenger car in Height, can be broken down. With according to the height classi- point B and on a truck in the point counts by ultrasonic detectors is th B and C hits. Roadway and vehicle surfaces, which are also very complex and also susceptible to failure, partially reflect the incident light back in a diffuse manner, so measurement of the transit time of the ultrasonic pulses at points Λ, B and C are secondary requirements. In addition, this is vehicles, the radiation sources. These radiation sources are imaged on a surface between two pulses, the measuring point pass through the converging lens L _2; not recorded. , _{ on which a group of photodiodes D ₀ , D ₁ , D ₂

The invention is based on the object, relatively with downstream amplifiers V ₀ , V ₁ , V ₂ and

simple and at the same time faultless vehicles are located under 35 counters Z ₁ , Z ₂ .

Consideration of the different vehicle classes The photodiodes are aligned and therefore to count. This includes the invention of the more expediently adjustable that each photodiode interpretation that the different heights of the radiation only absorbs one secondary source. the different types or classes of vehicles represents a suitable criterion, which, for example, cannot be made arbitrarily small, a truck versus a passenger. The secondary radiation sources are therefore not in identifies vehicles. Using a fixed height, but within certain limits Transmitter, which is a narrow, sharply delimited to the specified heights above the road Beam cone of intensity-modulated light effective, z. B. in the range 0 + 40 cm, 100 + 40 cm, radiates, and a receiver to convert and 45 200 + 40 cm. To the tolerance range as possible Reinforcement of the reflective narrowing of the roadway or vehicle, the light beam is shaped in such a way that it is aimed at Based light signals, according to the invention, the reflective surfaces are one in the direction of travel suggested that the line-shaped light mark running from the receiver as a secondary divider High altitude coming reflected source generated. By a (not shown in the drawing-rays a photoelectric converter assigned to each 50) slit diaphragm in front of the photodiodes can be is and that the transducers achieve a common optical then that the radiation over the whole System is connected upstream. Length of the slot on the surface behind it. The classification of the photodiode according to the invention therefore falls, but even at low heights Vehicles according to their height by taking advantage of changes in the secondary sources because of the lateral The short waves of infrared light no longer show any shift in the image in that this meets the simple measurement of the input by the photodiode.

The photodiode D ₀ has switches X and Y

Mood of the local position of the receiver only to make the counters ready to count

witnessed light mark image is traced back. and the beginning or the end of a counting step

You can proceed in such a way that 60 signals while the DiOUeD _{1 is} the counter

with a photo for passenger cars assigned to the road level, the diode D _{2 is} the counter

diode made the counters ready to count, which controls the truck.

and the beginning or the end of a counting step As long as the lane is clear, only the photo signal is received, while the remaining photodiodes diode D ₀ light, thus making the counting unit 65 of the counters Z ₁ and Z ₂ ready for counting within the counting step. When a person arrives, move forward one unit at a time. But there can be motor vehicles in the beam path, so the photo is also used the signal coming from the road to diode D ₁ by the light counting of the vehicles reflected at point B _{, so that the counter Z 1} by one

Unit is advanced. As soon as the vehicle is past, the photodiode D ₀ comes into effect again, which signals the end of the counting step and restores the readiness for counting. The same applies analogously in the event that a truck enters the beam path. Here both the diode D ₁ responds through a reflection at point B and the diode D ₂ through a reflection at point A. By the diode D ₂ the counter Z _{2 is switched on} by one unit and the counter Z _{1 is switched back} by one unit.

Instead of counters, data processing devices can of course also be used. Nor is the scope of the invention to counting vehicles in just two Classes or categories restricted.

Claims (3)

Patent claims: 1. Arrangement for the classified counting of ao vehicles according to their height using a transmitter that emits a narrow, sharply delimited beam cone of intensity-modulated light, and a receiver for converting and amplifying the light signals reflected from the road or vehicle, characterized in that the receiver _{A photoelectric converter (D 0} , D ₁ , D ₂ ) is assigned to each of the reflected beams coming from the different height ranges (A, B, C) and a common optical system (L ₂ ) is connected upstream of the converters. 2. Arrangement according to claim 1, characterized in that the optical system (L ₂ ) consists of a corrected lens system, for example an achromatic lens. 3. Arrangement according to claim 1, characterized in that in the presence of one Vehicle only the signal originating from the highest points of the vehicle in this altitude range assigned switching stage preferably responds once. 1 sheet of drawings