DE1816293A1 - Automatic extension of the green light-up time of intersection lights - Google Patents

Description

Patent attorney Registration: N.V. PHIiPS 'ULOEILAMPtHfAUKIEKEH

File. PHN- 3099
. 3099. Registration from 20 · Deaember 1968 1816293

Automatic extension of the green light from crossing traffic lights.

The invention relates generally to the control of Traffic congestion on the streets of a city and in particular the regulation of traffic at an intersection as a function of the the traffic density at the intersection at a given moment.

The existing adaptation systems are generally based on the principle of extending the time during which a certain Traffic light allows the passage of the vehicles over the active train, i.e. when the traffic light is green.

Every time a vehicle passes a detector there is a predetermined waiting time for the next vehicle. If no vehicle drives past during this time interval, changes the green light and the green light of the 'luerstreoke will light up. If, on the other hand, there is a vehicle, a waiting time occurs again. This waiting time is called the green extension time here.

It is well known that a fitted cross with a fixed extension is not gana satisfactory. The present Invention enables variable orunextension times to be achieved. It concerns a simple circle, which is characterized in that two units formed by the series connection of a resistor and a capacitor with very different time constants in parallel are connected to the terminals of a DC voltage source, the Connection points of the resistors and capacitors of the units duroh 'a diode or' a thnliohee element are connected to one another and which Capacitors of very different capacities at the beginning of the green light are discharged and 4s in the circle dor lower counterparts * recorded JCendeneator during a titled time i | discharged state We kept ** * $ · J * Mle weiofaer Z «lt ej nioh» uüuladen starts, but

immediately when driving past a vehicle at a suitable one Detector discharges, while the other capacitor is always and proportionally slowly charges so that after the minimumzoitsppan, which ends when the voltage across the capacitor of the lower time constant A definite date is reached, the Orünvarllin ^ Orungo period Depending on the traffic density between two "outer" Changes values, one of which is low.

The invention is explained in more detail with reference to the accompanying drawing.

Fig. 1 shows a circuit according to the invention. C, and C_

represent two capacitors j the capacitance of C_ is significantly higher than that of C ,, Each of these capacitors has an electrode with a fixed negative ßleiohspuhnungsquelle -V connected. The other two Electrodes are connected by a diode D, which leads from C. to C. The terminals of C are through a switch I, any Type that scalies itself for a very short time, if a detector of any type indicates the passage of a vehicle,

P, denotes an adjustable potentiometer between on the one hand the connection point of C- and D- and a positive one Glide tension source + V on the other hand.

F «also denotes an adjustable potentiometer, the between your junction of C, and D, on the one hand and one positive Oleiohspannungsquelle + V on the other hand is connected.

When the traffic light is green, the capacitors C ₁ and C _{2 are} discharged. During a predetermined minimum period, the capacitor C _{1 is kept} in the discharged state. The capacitor C _? 18dt sioh via the potentiometer P ₂ *

Aa Jihdt de * HinUiuozeit fBngt de »Capacitor C ^ an 3ich tt | # * dtn Pottntioaet · * J? ·» Ufiuladen,

BATH ORIGINAL

When a vehicle drives past a detector, switch I closes, whereupon it opens again almost immediately. The capacitor C ₁ is thus charged almost instantaneously.

If the voltage across the capacitor C _{1 is} lower than the voltage across the capacitor C ₂ , the capacitor C ₁ charges with the time constant P ₁ C-, which is significantly lower than PpCp

When the voltage across the capacitor C ₁ becomes lower than the voltage across the capacitor Cp, the pion capacitor C charges with the time constant P, (C, * O ₀ ), which is considerably higher than P ₁ C ₁ .

l / hen the voltage of _C1 reaches a certain value, the green extension time is terminated.

From this it follows that with high traffic density the green extension time retains a relatively high value; if the ■ Vehicles are further apart, the green extension time is shorter. When not a single vehicle passes by, the narrowing is no longer than a duration of P-i (C, + Cp). ■

On the other hand, if the traffic is constant for a certain time interval, the capacitor Cp gradually charges more and any prolongation after the discharge of the capacitor C ₁ seeks to shorten itself.

The results are partially illustrated in the graph of FIG during the Vorübv.-rfahrt * of a vehicle depending on the vlügenblick suggesting passage. . .'.- ..

The abscissa is the ¹ moment of passage. and as

The ordinate * is the duration of the green extension.

The Hull abscissa corresponds to the beginning of the green light.

The straight vertical ^% line D. en!. Corresponds to the minimum green time and the vertical D _? corresponds to the maximum grunzioit.

The straight line D ^ corresponds to a high traffic density

9 0 9 8 3 0/1016 [\

BAp

and the straight line D. corresponds to nearly Hull traffic.

The dashed line D ₁ . corresponds to a real, average one

Traffic. ■. . "

Claims (9)

PATENT CLAIM. . .'.-... · Simple circuit arrangement d.g ,, that two by the series connection Units formed by one resistor and one capacitor each with very different time constants parallel to the terminals of a Gleiohspannun & squelle are connected, the connection points of the resistors and capacitors thereof by a diode or the like element are interconnected and the capacitors with very different capacities are at the beginning of the time period, during which over one of the Stretches of a street crossing vehicles driving through the crossing and which corresponds to the green light of the street in question, discharged, so that the in the circle of the lower time constant absorbed capacitor in the discharged state for a fixed period of time is held, at the end of the same the capacitor begins to charge, but immediately during the passage of one suitable detector unloads passing vehicles while the other .Capacitor s & ets and ratio ™ "ssig slowly charges so that after the minimum time, which ends when the voltage across the capacitor reaches a certain value with the lower time constant, the Green denaturation time is a maximum of zero according to the traffic density. BATH ORIGINAL Extract ι. Simple circuit arrangement for adapting the extension the green time of the traffic lights at a road junction to the Verkohrsdiohte-auf everyone represents Streoken of the Crossroads. 9 09830/1016 -b- Blank page