DE2229284A1 - ROAD TRAFFIC SIGNAL SYSTEM - Google Patents

Description

SIEMENS AKTIENGESELLSCHAFT Munich, June 1, 197 2

Berlin and Munich Wittelsbacherplatz 2

2229284 72/2059

Road traffic signal system

The invention "relates to a road traffic signal system with a central programmer, "in which the signal generator of each traffic flow to be regulated independently via a single control channel through a receiving switch can be controlled in connection with time switches which can be stimulated by this and are designed as pulse counters.

For the central control of the light signal generator of a road traffic signal system are increasingly Calculator used. However, it only makes sense to use them if they actually have all the commands to control the intersection can give from the headquarters, so no programming work more needs to be done at the intersections. In order to achieve this with a few control channels, the signal generators of each independently regulated traffic flow already via a single control channel through a reception switch controlled in connection with this stimulable and designed as a pulse counter time switches. This makes it possible to prescribe every desired signal state at the intersection from the control center. However, no traffic-endangering Conditions due to the release of mutually hostile traffic flows - as they result from the geometry of the intersection - occur and therefore the necessary safety devices must be provided at every intersection. Because these safety devices today, however, work with electronic switching means and therefore also briefly incorrect switching of the signal lamps would have to detect creeping signal changes

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must be avoided at all costs.

The invention is based on the object of these "two To bring demands in line with each other. The entire traffic flow should be handled by the computer in the control center programmable and controlled via as few transmission means to the intersection as possible. Nevertheless, everyone should Traffic hazards can be avoided by using quickly responding test equipment.

According to the invention, this is done in a road traffic signal system with a central programmer in which the signal generator of each traffic flow to be regulated independently via a single control channel through a receiving switch can be controlled in connection with time switches which can be stimulated by this and are designed as pulse counters achieved by the fact that the pulse counters of an intersection each have a special clock generator that they share can be incremented, and that this can be switched on at selectable time intervals, e.g. once per signal image cycle, from the control center by means of a synchronizing pulse can be synchronized that its Timing cycles at the beginning of all command identification signals from the control center are sufficiently out of phase with respect to each other are. It is also advantageous if the synchronization pulse from the control center to the intersection via a separate Control channel is transmittable. Furthermore, this synchronization pulse can also be tapped on the switching edge of a command identification signal.

Further details of the invention emerge from the circuit diagram of an exemplary embodiment shown in the drawing.

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Show it

Fig. 1 shows a simple intersection with the associated Signaling devices and "traffic flows,

2 shows a circuit arrangement with a programmer in the control center and the signal generators on one Crossing,

. 3 the signal plan for the crossing to Pig. 1 regulating signal transmitter,

Pig. 4 the detailed drawing of a control unit for vehicle signaling devices,

Pig. 5 a table for the control device according to Pig. 4, Pig. 6 a control unit for pedestrian signaling devices,

Pig. 7 a clock generator for the circuit arrangement according to Pig- 2,

Pig. 8 shows a timing diagram for the clock generator according to Pig. 7 and

Pig. 9 a test device for monitoring the correct signal pattern sequence.

The four vehicle flows 1 to 4 and the four pedestrians rivers 11 to 14 of the crossroads Kr according to Pig. 1 are through eight signal generators, namely the signal generators Sg1 to Sg4 for the vehicle and the signal generator sg11 to sg14 for the Pedestrian traffic can be regulated. It is evident that when the vehicle traffic 1 is released, the vehicle traffic flows 3,4 αηά the pedestrian flows 13, 14 are to be blocked, otherwise Traffic hazards can occur. The corresponding stop lamps in the associated signal generators Sg3, Sg4 and Sg13 » sg14 must light up when the stop lamp in the signaling device Sg1 goes out. This is ensured by a test device Pe according to FIGS. 2 and 9, which will be explained later.

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To control the intersection Er from the control center Zj3 can, are according to Pig. 2 for the vehicle signal generator Sg1 "to Sg4 the control devices St1 to St4 and for the pedestrian signal generators sg11 to sgH the control devices st11 to stH intended. (All components in Pig. 2 are identified by two-letter reference numerals, the components in the individual devices St, st, Tg, Pe, etc., on the other hand, denoted by one-letter reference characters)

These control units St or st can be used in conjunction with the clock generator Tg they share at the Kr junction can be controlled by the programmer Pg in the control center IZe via a respective control channel Pl. This programmer Pg is indicated here only symbolically by a rotary selector Dr and an information contact Inf. This is supposed to show that the memory switches Sd to Sd4 are in the buffer memory Sp can only be set one after the other. In fact, the programmer Pg is generally a computer or a similar electronic device and one of the usual in the case of the buffer memory Sp Computers used peripheral devices that can be used as temporary storage.

Each time the signaling status changes, the Commands from the control center _Ze to the individual signal generators Sg1 to sg14 are not simultaneous, but rather against each other transmitted out of phase. This has the Polge - as is to be explained later with reference to the testing device Pe - that the necessary stop lamps do not light up immediately. In order to but the safety lamp S1 could light up as a warning and at the same time via the switch β · ί «& the entire signal system be turned off at the junction Kr.

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To explain this, the Pig. 3 this creeping signal image change and the possibilities to remedy it are discussed. From Figure a it can be seen that in the time range between the second 0 and 1, the switches sd to sc4 or sc11 to sc14 are actuated one after the other and thus the control units St1 to st14 are also switched out of phase. If the second cycle is only given by the clock generator Tg when all of the command identification signals for the signal image change have actually been transmitted in this area between seconds 0 and 1, then all control units St1 ... st14 and thus also the signal generators Sg1 to sg14 switched simultaneously (see Fig. B for Pig. 3). The individual signal images red, red / yellow and green for the signal generators Sg1 to Sg14 are indicated in picture c of FIG. 3. The time scale has been changed accordingly for better representation Clock generator Tg, which allows a minimum time of 500 milliseconds to elapse between the synchronization pulse from switch sco and the clock pulse.

In the pig. 3 it is also indicated that a command identification signal, E.g. that for the signal transmitter Sg1, can be used as a synchronization pulse. This one becomes on the advanced plank of this command identification signal tapped, as by the one drawn in black Section and the arrow is indicated.

Pig. 4 shows the structure of the control units St for the individual vehicle signal generators Sg. None should be present at input q Voltage is present and the toggle switch K1 is over

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its input inverted by a point in the rest position. The toggle switch K2 is also in the rest position. Voltage is therefore present at their outputs al and the red lamp in the signal transmitter Sg lights up. If voltage is applied to input q from the control center Zje, it switches the toggle switch K1 into the working position in conjunction with a corresponding pulse via input u from the clock generator Tg. Then there is voltage at the outputs of the Uand gates G1, G2, so that the yellow lamp in the signal transmitter Sg also lights up via the NAND gates G3, G4. At the same time, the counter Z1, which was previously held in the zero position _{via its reset input R 0, is also started.} After the specified time, for example after three seconds, the counter Z1 sends a pulse to the manual gates G5, G6, which bring the toggle switch K2 into working position in conjunction with a pulse from the clock generator Tg. The toggle switch K2 sends voltage to the green lamp via the Ifand gates G-9, G1O and other circuit breakers, not shown here, and lets the red and yellow lamps in the signal generator Sg go out. In addition, the counter Z1 is reset again via its reset input R ₀ . If the voltage at input q is switched off after a while in the control center _Ze, this brings the toggle switch K1 back into its rest position together with the second cycle from input u. This switches off the green lamp via the NAND gates G9, & 1O, while the liand gates G1 to G4 only switch on the yellow lamp. The reset input R _{0 of} the counter Z1 is also released, which after a specified time, for example this time after four seconds, returns the toggle switch K2 to its rest position via the NAND gates G7, G8 together with the second cycle from the input u. Now only the red lamp in the signal transmitter Sg lights up again and the counter Z1 has been reset to its zero position. in the

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Control unit St are nocti the "two Uand gates G11, G12 intended. About this is always then at the output ν Voltage is on when only the red lamp in the signal transmitter Sg lights up.

In Fig. 5 are the commands for the signal generator Sg, the logical States at the outputs of the individual switching units as well as the lighting up of the red, yellow and green lamps in the Signal transmitter Sg compiled in a table,

Fig. 6 shows a simple control switch st for the pedestrian signal so called. If there is no voltage at input q ', the toggle switch K3 is in the rest position and the red lamp in the signal transmitter sg lights up. If, on the other hand, ^{voltage is applied to input q 1} from the control center! Ze, the next following second cycle from clock generator Tg via input u brings toggle switch K3 into the working position and switches on the green lamp in signal generator Sg. Here, too, voltage is only ever present at output ν when the red lamp lights up.

In Pig. 7 shows the common clock generator Tg for the crossing Kr. At first there should be no voltage at input w, so that the toggle switches K4, K5 over the through a point inverted input e2 of the toggle switch K4 are in the working position. AC voltage with a frequency of 50 is present at input χ Hz on. The clock T acts on the toggle switch K4-i K5 and the counters Z3, Z4 with a frequency of 100 Hz. ' The latter act as a frequency divider and can send one clock per second via the Uand gates G15, G18 at output y hand over. When a synchronization pulse arrives via the switch ScO, sco from the control center Ze_ at the input w des Clock Tg, the toggle switches K4, K5 are successively from

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the next two bars of the clock T brought to their rest position. In the intermediate phase, when the toggle switch K4 is in the rest position and the toggle switch K5 is in the working position, the counters Z3, Z4 receive a reset pulse via the FAND gates Gf-13, G14 to the reset inputs R ₀ , R50 through which the counters Z3, Z4 can be synchronized and brought into the counting position "500". The pulse at output y following the synchronization pulse is thus emitted after just 500 milliseconds. But that’s like Pig. 3, the second cycle from the clock generator Tg has been shifted by 500 milliseconds compared to the synchronization pulse from the control center _Ze. This avoids any risk of a gradual change in the signal image.

In Pig. 8 are the synchronization pulse from switch sco, the pulses from the clock T and the switching behavior of the toggle switches K4, K5 of the NAND gate G14, the counters Z3, Z4 and the time delay tv = 500 msec between the synchronization pulse and the timing of the clock Tg in the range between the 20th and 21st second on the time axis t is shown with different scales.

Pig. 9 finally shows the structure of the test device Pe. The individual outputs v1 to v14 of the control devices St or st according to Pig. 2, the OR gates 01, 02 are linked to one another in a certain logic via the manual gates G 17, G18lin%. There is no voltage at the output of the common hand gate G 19 as long as either the red lamp in the signal transmitter Sg1 or the red lamps in the signal transmitters Sg3, Sg4, sg13, sg14 or the further required red lamps of the other signal transmitters Sg2 etc. light up. Then traffic-endangering conditions can by no means occur. If one of these

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Red lights off, so lights up over the common Uand gate G 19 the safety lamp S1 in the control center! Ze on and at the same time the switch Sch, sch die entire traffic lights at the crossroads Kr switched off.

J5 claims 9 figures

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Claims (3)

Claims Μ. / Road traffic signal system with a central programmer, in which the signal transmitter of each traffic flow to be regulated independently has a single one Control channel through a receiving switch in connection with this stimulable and designed as a pulse counter Timers are controllable, characterized in that the pulse counters (Z1) at an intersection (Er) can be advanced by a special, but common to them clock generator (Tg), and that this at selectable time intervals, e.g. once per signal image cycle, so that it can be synchronized by the control center (Ze) by means of a synchronization pulse, that its clocks are each sufficiently phase-shifted at the beginning of all command identification signals from the control center (Ze) are. 2. Installation according to claim 1, characterized in that the synchronization pulse from the Central (Ze) can be transmitted to the intersection (Kr) via a separate control channel. 3. Plant according to claim 1, characterized z ei ch η et that the synchronization pulse can be tapped on the switching edge of a command identification signal. 309881/0219 Lee side