AU721393B2

AU721393B2 - Process for identifying a vehicle on a road

Info

Publication number: AU721393B2
Application number: AU35387/97A
Authority: AU
Inventors: Wolfgang Detlefsen; Wilhelm Grabow; Rainer Schmedding
Original assignee: Kapsch AG
Current assignee: Kapsch AG
Priority date: 1996-08-17
Filing date: 1997-07-09
Publication date: 2000-06-29
Anticipated expiration: 2017-07-09
Also published as: EP0919000A1; KR20000068095A; DE19633240A1; AU3538797A; WO1998008110A1

Description

-1- Prior An The invention relates to a system for identifying a vehicle on a road with a beacon situated in a transmit-receive field and carries out, with an on board unit, a data transmission.

In the area of comprehensive traffic management are, in the future, many new services for which the position of the vehicle must be registered with which communication is being carried out. In particular, in the case of services for which payment is required, eg. in the automatic charging of toll fees for the use of roads or in the checking of the right of vehicles to use certain carriageways, it must be established that also in the cases when several vehicles are situated on several carriageways in the transmit-receive range of a beacon, the instantaneous transmission of data will be allocated to a single automobile. By means of an appropriately specific evaluation, those vehicles which have no right to use the carriageway can be captured on video. From the publication "Micro strip array antenna for an automatic road pricing system", European Microwave Conference 1993, Madrid, pp. 351-353, it is 0* known that, by means of several microwave antennae on carriageway, such narrow communication zones can be built so that only one vehicle at a time can be situated within the communication zone. In this case, eg. several permanently aligned antennae can be provided per carriageway. According to DE-OS 42 22 014, an antenna arrangement is provided producing, Selectronically, a tracking, a directional plot onto a certain vehicle of a type 25 that a main reception lobe is directed onto the vehicle in question and in the direction of another, adjacent object, the reception loss with respect to the main reception lobe is high.

The cost of technology for each of these solutions is comparatively high. A further problem arises in that large communication zones in which several vehicles can be situated are not possible. On the other hand, however, it is J Ll, \desirable that certain non-chargeable information and warning services to as 14/04/00,td 10304.spe, 1 -2many vehicles as possible whenever, eg. as the result of an accident, a traffic jam threatens or storm-related disturbances exist. Furthermore, in a large communication zone, more time is available for the transmission of data so that even vehicles travelling very quickly can be registered.

Summary of the Invention The present invention provides a system for assigning a certain data transmission of several transmissions taking place between a radio beacon and one of a plurality of vehicle devices moving at various positions in the transmit receive field of the radio beacon to the respective vehicle device picking up this particular data transmission, a velocity evaluation unit connected to the radio beacon which ascertains a velocity value of the vehicle device processing this particular data transmission, a sensor and evaluation unit determines the positions of the all the vehicle devices moving in the transmit/receive field and their respective velocities at the time of a -transmission of data and the output of the velocity evaluation unit and the output of the sensor and evaluation unit being directed to the input of a 9* *9 9* comparison and assignment unit said comparison and assignment unit, assigning the particular data transmission to the respective motor vehicle .9 device by means of the comparison of the velocity values assigned to the data transmissions with the velocities belonging to the vehicle device positions.

o Advantages of the Invention S r. The system of the invention for the identification of a vehicle has, as opposed to the prior art, the advantage that the solution proposed represents a simple S procedure for the clear allocation of a vehicle position and a transmission of data with the aid of the speed measurement at a beacon and a sensor. It is of particular advantage that the procedure sets no particular demands or amendments with regard to the carrier frequency, band width, modulation or S tr nsmission of special data sequences. It is, for this reason, fundamentally 14/04/00,td 10304.spe, 2 2a compatible to the future standard of short range data transmission, at 5.8 GHz, for use in traffic. The relative speeds recorded by the beacon and the sensor are compared, the correlation representing a measurement for the clear recognition of a vehicle.

It is advantageous, then, if the measurement of speed by the beacon and sensor takes place simultaneously, as then the correlation of the speeds represents a certain gauge for the identity of a vehicle. Moreover, the measurement of speed can take place at every communication attempt. The measurements can be most easily produced by the sensor.

In order to reach an even higher level of reliability of the procedure, a second beacon can also carry out a measurement of speed.

The arrangement of the beacons should, for the greatest advantage, be arranged symmetrically to the carriageway.

9it In order to attain a redundancy or the measurements, the measurement must l be repeated at certain time intervals.

The entire process can be employed for automatic collection of toll fees and the control of the right to use carriageways.

.e *SS. 9 9ll 14/04/00,td10304.spe,2 WO 90C8110 PCT/DE97/01445 -3- Diagram Two embodiment examples of the invention are shown in the diagram and are described in detail in the following description. Figure 1 shows a first embodiment example, Figure 2 a second embodiment form.

Embodiment Example Figure 1 shows a section of a road (10) with two carriageways, a vehicle 1 (F1) on the left carriageway, a vehicle 2 (F2) on the right carriageway, both travelling toward the beacon.

The vehicle 1 (Fl1) travels with a speed V 1 and has an on board unit OBU4 with which it carries out a transmission of data to the beacon for example according to the transponder procedure in the microwave frequency area, preferably at 5.8 GHz. The beacon has appropriate transmitters with one or two antennae which cover one part of the road as communication zone. Their transmission frequencies can be set according to DE- OS 42 13 880. A transmit-receive device is, for example, known from DE 41 07 803 and, for this reason, need not be described in detail. The signals from the vehicles 1 and 2 are received by the beacon It is important that each beacon determines the vehicle's speed in the transmission of data from the vehicle to the beacon directly from the signal in the beacon. The speed is measured through the arrangement of communication zones in the direction travelled in front of the beacons fundamentally travelling toward the beacon. An appropriate procedure is described in DE 43 31 286. In this connection, the type of modulation used in the on board unit and the principle of "mixing down" in the beacon are employed. The additional circuitry input of a corresponding evaluation unit in the beacon is relatively slight and therefore particularly economical. The measurement of the speed of the vehicles cannot take place directly as the vehicles do not move directly towards the beacon but drive past it. The measured speeds VIR and V 2 R to the beacon are less than the actual vehicle speeds V1 and V2. The beacon measures the speed VIR VIcosa cosy, and V 2 R V 2 cos3 cosy 2 a and 13 are the respective angles between the vehicles in the xy-plane and yl, yt2 the angles in the xz plane. In addition to the measurement of speed of the beacon the position and the speed of the vehicles must be determined by sensors. Here the employment of all -4sensors which can carry out a determining of position and a measurement of speed is possible. Suitable are, eg. induction loops in the road or radio, video or intrared sensors. The sensors S1 and S2 determine the position of the vehicles F1 and F2 to x, z 1 and X2, y2, z2 with the speeds v, and v2 In order to make possible the allocation of the vehicle position to the measured speeds belonging to them, the speed measured by the sensor must be so corrected as if it were measured by the beacon For the known beacon position XB, ye, ZB, the angles a*and 3* as well as P* and yl and y2 under which the beacon would have been able to measure the signals can be determined in the evaluation unit S Yi-YB -J (Yi- Ya) 2 a =arctg yi =arctg X XI-XB ZB-ZI S Y-YB j(X2- B) p =arctgX B y 2 arctg With this, the speeds V1R* V osa* cosy and V2R* cosp* cosy2 calculated from the sensor data are established.

*9 The comparison of the speed V1R and V2R and measured by the beacon with the speeds V1R* and V2R* calculated from the sensor data allow an allocation of the vehicle position to the speeds measured during the data transfer.

With this, the required allocation of the vehicle position and data transfer is produced. The comparison permits an evaluation of the quality of the result.

The smaller the difference of measured speeds (VR* V2R), the more certain the result. If similar speeds are measured for both vehicles, an allocation during this data transfer is not possible. The next data transfer which typically -takes place after a few metres is determined by changed geometric rionships of varying speeds and with it an assessable result is shown. If 14/04100,td10304.spe,4 4a the vehicles are standing still, no speed can be measured and an allocation is not possible at this moment. In this case, however, the vehicles remain for a long time in the communication zone. The query by the beacon can be carried out by starting the cars. The starting itself is detected by the sensor system.

The proposed procedure represents a simple solution to the allocation of vehicle position and data transfer through the measurement of speed. As the -4 4 5* 9*4* o* S *ae 14/04/00,td10304.spe,4 It procedure requires not particular requirements or changes with respect to carrier frequency, band width, modulation or the transmission of special data sequences, the procedure is, in principle, compatible to the future standard of the short range data transfer at 5.8 GHz for use in traffic.

Further Embodiment Examples By means of the installation of more than one beacon, the reliability of the allocation of the data transfer to the vehicle positions measured can be increased as several speed values VR1... n per vehicle of the respective beacons 1 n are available. The measured values can, via the transmitted data, be allocated to the vehicles. In Diagram 2, a system with two beacons and (12) are depicted as examples. Through the additional information of the nth speed measurement a clear allocation is to be expected.

By means of repeated queries of the beacons, multiple speed measurements S" can be undertaken. By means of several comparisons of the measurement results with the calculated values, a certain allocation is guaranteed through correlation.

.9 Alongside the determining of position and the determining of speed, the :Ill sensors can, at the same time, be in a position to carry out a vehicle 9999 199• oo ~classification in groups such as, eg. passenger cars or trucks as is necessary a for, eg. the right to drive on a section of road or for the extracting of a toll 060: S: 25 fee. With the use of video technology, the documentation of non-payment and incorrect payment is further possible.

99 9 l.

9 c 28/0400,td 10304.pg5,5

Claims

1. A system for assigning a certain data transmission of several transmissions taking place between a radio beacon and one of a plurality of vehicle devices moving at various positions in the transmit receive field of the radio beacon to the respective vehicle device picking up this particular data transmission, a velocity evaluation unit connected to the radio beacon which ascertains a velocity value of the vehicle device processing this particular data transmission, a sensor and evaluation unit determines the positions of the all the vehicle devices moving in the transmit/receive field and their respective velocities at the time of a transmission of data and the output of the velocity evaluation unit and the output of the sensor and evaluation unit being directed to the input of a comparison and assignment unit said comparison and assignment unit, assigning the particular data transmission to the respective motor vehicle device by means of the comparison of the velocity values assigned to the data transmissions with the velocities belonging to the vehicle device positions.

2. The system as claimed in Claim 1, wherein the sensor of the 20 sensor and evaluation unit triggers the start of the measurement of velocity in the velocity evaluation unit. re

3. The system as in claimed in claim 1 or 2, wherein a second radio beacon with a connected speed evaluation unit is has its output directed to a further input of the comparison and allocation unit in order to improve the reliability of the allocation. Dated this 13h day of April, 2000. Dated this 13 t day of April, 2000. KAPSCH AKTIENGESELLSCHAFT By their Patent Attorneys: &'iT .NAN LAWRIE 14/04/00,td 10304.spe,6