DE2719675A1 - Traffic light monitoring system - has radio signal transmissions for remote detection of traffic light unit malfunction - Google Patents

Abstract

A monitoring system based upon a remote transmitter/receiver station, enables any faults in a traffic light system to be quickly detected and alternative actions produced. The system uses continuous test signals that are transmitted as radio frequency signals to each traffic light unit in sequence. When each unit is operating correctly a specific time interval between transmission and reception occurs. Any difference in timing interval identifies a fault.

Description

"Procedure for monitoring the functional

efficiency of the traffic lights of a radio-controlled traffic light system the The invention relates to a method for monitoring the functionality of the traffic lights a radio-controlled traffic light system.

With a radio-controlled traffic light system, it is necessary to Check the functionality of every single traffic light as quickly as possible and to adjust the entire system accordingly in the event of a malfunction.

The present invention has set itself the task for a radio-controlled Traffic light system to develop a monitoring process with which the The functionality of every single traffic light is checked and, in the event of a malfunction, the whole Traffic light system can be converted to this incident.

To solve this problem it is proposed according to the invention that the traffic lights one after the other via radio from a common receiver and transmitter station communicate their undisturbed condition, and between the communication of two to each other signaling traffic lights there is a fixed radio gap, and in the event of a malfunction of the disturbed traffic light using the radio gap, the remaining traffic lights can be switched to fault at the same time.

The invention also provides that in the event of a transmission and reception inability one traffic light, the common receiver reports the incident to all traffic lights.

The invention is further characterized in that the sum of the notification time of each traffic light to the common recipient and out of the radio gap maximum 300 msec. amounts to. The same applies to the case when the common recipient takes on the task of a traffic light that is unable to transmit or receive.

The advantages achieved with the invention are: that this process technology applies to both stationary and mobile traffic light systems Can apply, and in all cases the safety requirements to be fully fulfilled.

A particular advantage is the fact that in the event of a complete failure a stationary traffic light system, this can be replaced by a mobile one as quickly as possible can without neglecting the safety requirements.

The method according to the invention is described in more detail below; the functional sequence is illustrated in the drawing.

The central receiving and transmitting station, hereafter the control unit called, * have a radio transmitter and a radio receiver. After switching on the Traffic light system, all traffic lights expect a special command from the central control unit via radio. With this command, a time lapse begins in each individual traffic light.

At a time programmed differently for each traffic light within this lapse of time it becomes the radio transmitter of the concerned and each individual Traffic light of the system Traffic light is activated and sends a coded acknowledgment signal back to the central control unit. The coded acknowledgment signal contains the information that the radio transmitter and the radio receiver of the traffic light are working correctly. The temporal The length of the acknowledgment signal is e.g. 100 msec.

The times programmed in each traffic light for the sending of the acknowledgment signal are chosen so that the central control unit receives a chain of acknowledgment signals, all e.g. 100 msec.

are long and between them there is also a radio gap of e.g. 100 msec. lies.

The number of traffic lights in a system, whose acknowledgment signals the central one Control unit has to receive, is preselected with a switch on this. After this the central control unit has received the acknowledgment signal from all traffic lights it again issues a command that starts the timing in the individual traffic lights again.

The process repeats itself.

If the radio transmitter of a traffic light fails or the recipient could Traffic light does not receive the start impulse from the central control unit and thus the time lapse If the traffic light does not start properly, the central control unit registers the failure of the acknowledgment signal.

It now uses the immediately following radio gap of e.g. 100 msec., to transmit a sustained emergency signal via radio to all other traffic lights. This The emergency signal switches all traffic lights to the incident.

If there is a malfunction in a traffic light, the transmitter transmits it Traffic light immediately emits a sustained emergency signal. This radio distress signal can in the worst case, exactly in time with the acknowledgment signal sent out at that moment coincide with another traffic light, however, since the acknowledgment signal only lasts for e.g. max. 100 msec. is sent, the emergency signal takes place after 100 msec.

following gap free access to the recipients of all other traffic lights and causes the switch to malfunction.

The possibility that a traffic light will then also send out its emergency signal can, when disconnected from the power source, was created by that every traffic light has an internal backup battery that provides power the radio transmitter also ensures that an external power source fails should be.

Using this procedure it is possible to have a radio controlled Constantly monitoring the traffic light system and switching all traffic lights in the event of a malfunction within max. 300 msec. to reach.

L e r s e i t e

Claims (3)

Learn about patent claims to monitor the functionality the traffic lights of a radio-controlled traffic light system z e i c h -u e t that the traffic lights one after the other via radio to a common receiver and transmitting station to report their undisturbed state, and between the notification there is a timed radio gap between two traffic lights reporting on each other, and in the event of a malfunction from the disturbed traffic light using the radio gap the other traffic lights are switched to fault at the same time. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t, that in the case of an inability to send and receive a traffic light the common Receiver reports the incident to all traffic lights. 3. The method according to claims 1 or 2, d a -d u r c h g e k e n n z e i c h n e t that the sum of the notification time of each traffic light at the common recipient and from the point gap a maximum of 300 msec. amounts to.