Warning device for motorists

The invention relates to a method for warning motorists in which at least one radio frequency range is transmitted with a transmitting device on several different frequencies stored in a frequency memory.

The need for warning devices and procedures for motorists has not diminished for a long time5, since there are many situations, not infrequently life-threatening, in which a warning should be given as quickly as possible, reaching a group of motorists as reliably as possible. Examples of such situations are generally known from daily traffic announcements; In particular, however, the eminent danger from wrong-way drivers should be pointed out.

Common to all known warning systems is their relatively great inertia. For example, until a wrong-way driver report has reached the endangered driver, several minutes pass from the detection of a wrong-way driver in the best case, since the report must first reach a radio station, which then emits a warning.

Other, mostly optical or acoustic warnings from display panels, flashing lights or horns are often overlooked or ignored by drivers.

A warning device or a method of the type mentioned is based on the

DE 40 05 445 A1 emerges. With this warning device, an accident vehicle should repeat an announcement on the three to five strongest frequencies. Apart from the fact that a pilot tone is mandatory here, the cyclical announcement on several frequencies leads to delays of the order of one minute if, for example, only the last frequency 20 within the cycle is received. For example, it is hardly possible to warn a wrong-way driver because he has already covered a long distance within the specified time and is therefore also outside the transmission range or may have already caused an accident.

EP 0 942 402 A2 describes an emergency warning device for emergency vehicles which, in addition to acoustic and / or optical warning signals, emit a warning on a frequency in a radio band. This happens on a single fixed frequency, ζ. B. at the upper or lower end of the VHF broadcasting range, assuming that the receiver is then tuned to this frequency. For receptions with two HF input sections, which are de facto required, one HF stage must have an automatic transmitter search. 30 The disclosed device therefore not only requires special recipients from the road users, but is also characterized by additional delay times due to the voting process.

One object of the invention is thus to create an effective warning method which, in particular when triggered by an event, transmits warnings to motorists largely without delay. Above all, it should be possible to warn wrong-way drivers in good time before they reach the actual road or motorway.

This object is achieved with a method for warning a motorist, in which, according to the invention, warning messages are transmitted simultaneously on several different frequencies via at least one antenna.

The principle on which the invention is based is based on the fact that drivers located in a certain danger area have switched on a radio receiver in the majority of cases, usually in the VHF radio range in Central Europe. Since, according to the invention, warning messages on several, ζ. B. 20th Frequencies are emitted at the same time, it is actually possible to reach every motorist who listens to the radio or at least has switched on his device, provided of course that on the one hand the locally relevant frequencies are selected and the transmission power is sufficient to operate in a narrowly limited space Area to displace the currently set radio station in terms of HF.

In an expedient variant it is provided that acoustic warning messages contained in at least one memory are sent out. For example, the text "Caution you have used the wrong driveway and are wrong-way drivers" or acute black ice risk "etc. could be stored in a memory 50 so that the warning can be understood without further consideration.

It is also advantageous if a trigger signal for the transmission device is generated by at least one sensor, since this results in no further delays, ζ. B. by operating personnel, a 55 warning can be initiated. Sensors that come into question here are known, for example

AT 411 634 B inductive loops in the roadway, temperature sensors, smoke gas sensors etc.

In a very effective variant, it can be provided that when a trigger signal occurs, warning messages from the memory are passed to the transmitting device as messages to be transmitted, and the transmitting device is activated. As a result, if a wrong-way driver is detected by means of a corresponding sensor, the wrong-way driver warning is transmitted from the memory practically without delay.

In a practical and economical implementation, it is provided that modulated carriers of several carrier generators with modulators assigned to them are fed to a common RF output stage of the transmission device.

In an advantageous variant of the invention it is further provided that the transmission power of the common output stage is dimensioned so large that radio transmitters in a receiver of a motor vehicle can be displaced within the intended warning range.

In the interests of high efficiency and freedom from maintenance, provision can be made for a stationary monitoring receiver with at least one antenna to scan through the at least one radio frequency range at predefinable time intervals and to feed frequencies from broadcast transmitters corresponding to recorded and predefinable criteria to the frequency memory of the transmission device for storage. Since it is not known which stations the motorists to be warned have just tuned in, this measure has an extremely high probability of actually reaching the motorists. It is particularly appropriate here if the specifiable criteria include a minimum field strength at the at least one antenna. Certain RDS identifiers can also expediently be assigned to the frequencies.

The flexibility and economy of the warning device can be increased if, in the non-scanning state, the monitoring receiver monitors a predefinable frequency of a transmitter with RDS function for messages and forwards received messages to the transmitter and / or to controlled display devices.

In order to reach drivers who have turned their radio down or are listening to tape or CD, it is advisable for the transmitter to emit a traffic announcement bit with the support of the RDS system.

To increase the effectiveness of the warnings, it can be useful if the transmitting device, with the support of the RDS system, emits an alarm bit.

It is practically easy to implement and effective if the at least one antenna is implemented by a guide rail section.

The invention together with further advantages is explained below using an exemplary embodiment with reference to the drawing. 1 shows the basic structure of a warning device according to the invention,> FIG. 2 shows the invention in a simplified block diagram and> FIG. 3 shows the transmission device with its modulators in a block diagram.

As can be seen from Fig. 1, a transmitter TRX, which can radiate via an antenna SAN, equipped with a frequency memory FME has an output stage HFE, a modulator block MOD and a frequency memory FME for a number of frequencies, for example in the VHF radio band that in the is generally between 76 and 108 MHz.

The frequency memory FME can store the frequency specification here either from a scanning receiver UWE or from another, ζ. B. also receive manually operable input ENG. An antenna EAN is assigned to the receiver UWE, but if generally known precautions are observed, the transmitter TRX and receiver UWE can have a common antenna.

The modulator block MOD can be an audio signal s_s from a voice memory SSP and / or a further, in particular digital signal s_d supplied from another source QEL.

The invention also provides that the transmitter TRX based on a trigger signal s_a is started up, which can come from a sensor SES, which ζ. B. is triggered by wrong-way driver cars. The trigger signal s_a can, however, also come from another source SOV, in the simplest case a manually operated switch.

Referring to Fig. 2, it can be seen that the scanning receiver UWE is followed by a spectrum analyzer SAL, which here scans the entire VHF range, with transmitters or their frequencies whose reception field strength is below the minimum field strength required for normal radio reception being ignored. After one or more

AT 411 634 B

Runs thus result in an occupancy spectrum of the possible frequencies that is representative of the receiver location. The determined frequencies, twenty in the example described, are then stored in the frequency memory FME.

Since the frequency spectrum can change over time, ζ. B. by new transmitters or 5 overreaches, you can periodically scan, ζ. B. repeat daily in order to update the memory content of the frequency memory FME.

As can be seen from Fig. 3, the modulator block MOD in this embodiment contains twenty carrier generators P01 ... P20, the ζ. B. are based on PLL and their frequencies are determined by a frequency signal f from the frequency memory FME. The generators P01 ... P20 are followed by individual modulators M01 ... M20, the outputs of which are fed to the common HF power output stage HFE via a coupling network KOP. The single modulators M01 ... M20 are the signals s_Sl s_a (see Fig. 1) supplied.

In the following, the function of the exemplary embodiment or its variants is explained in more detail with reference to the drawing figures.

In the area of ​​a motorway slip road there is on the one hand the SES sensor - of course, there can also be several sensors working according to different principles - and on the other hand a warning system connected to this, consisting of the UWE monitoring receiver and the TRX transmission device. Vehicles approaching the autobahn against the direction of travel trigger the SES sensor so that the HFE output stage is started up and a warning message from the SSP voice memory is broadcast on twenty radio frequencies at the same time.

The warning device is set up here in the vicinity of the sensor SES and the transmitting antenna SAN can be formed, for example, by a correspondingly isolated and measured section of a guardrail. The transmission power of the output stage HFE is such that in a range of a few hundred meters the signal is strong enough to displace other transmitters in the receiver of a motor vehicle. Thus, the “beginning wrong-way driver can be warned and pointed out via his car radio that he is about to become a wrong-way driver. It is understandable that if possible one will use an antenna for the transmitter that has less omnidirectional characteristics, but rather covers the roadway in question as precisely as possible and as far as possible.

The reading of the possible frequencies into the frequency memory FME by the monitoring receiver UWE has already been described above. It is also possible to use other criteria for the selection in addition to the reception field strength. For example, by reading out the RDS identifier, a locally strong incoming but foreign station can be ignored, since there is a high probability that it will not be received by drivers on their radio.

Since the UWE monitoring receiver is constantly in operation, it can also be controlled via RDS from a control center in order to prevent other information such as ζ. B. to enable traffic jam reports. For this purpose, the monitoring receiver USW is programmed in such a way that it only ever receives one radio program in the rest phase.

The RDS can also be used for paging and is also used, other pre-stored messages or displays, such as controlled traffic signs, can also be sent or displayed.

In addition to warning messages, the aforementioned traffic announcement bit TA can also be emitted to ζ. B. to switch from CD to radio, 45 and also an alarm bit AB, which triggers other functions, ζ. B. for emitting a loud tone, can be used.

Finally, it should be pointed out that the invention preferably has a stationary warning device on ζ. B. provides for places endangered by wrong-way drivers that the warning device could be used with many advantages but also in police vehicles etc. as well as in traffic helicopters 50 in order to be able to address drivers in emergencies.