DK2924662T3 - ONBOARD DEVICE AND PROCEDURE FOR FUNCTION MONITORING IN A ROAD CIRCUIT SYSTEM - Google Patents

Description

Onboard unit and method for functional rrionitoring in a road toll system

The present rnvention relates to an onboard unit for a road toll system, comprising a satellite navigation receiver for contiriU” ousiy generating position fixes and associated quality measure-values from satellite ravj data, a radio transceiver, and a Processor connected to these components, which is configured to sOnerate toll data from the position fixes and to send the toil '-a via the radio transceiver. The invention also relates to a !--hod for function surveillance in a road toll system viith the 3-i-d of such an onboard unit. ^'hDoard units (OBUs) based on satellite navigation systems ^P-i-obal navigation satellite systems, GNSS) can be "thick cir-ent" C)}3Us for example, which coiripare the generated position fiX" &s With a digital road map stored in the onboard unit, in doing determine road sections that are subject to a fee, calculate Associated toll fees, and send this .information as to.ll data via -he radio transceiver, but can a.lso be "thin client" OBUs, whicn ^-^lectly send the position fixes as toll data to a central sta~ which calculates the toll fees on this basis. The func~ li-onality and efficiency of such GNSS OBUs is largely depenaent the quality of their satellite reception and the position determined therefrom. EP 1 696 207 A1 describes a method for classifying position fiX" wherein invalid position fixes are rejected or labelled on Ihe basis of their quality, and, of those position fixes that have usable satellite raw data, only these raw data or raetaaat=" derived therefrom, but not the position fixes themselves, used.

Whereas the billing of the toll fees is usually taken care of by road operator or an authority, i.e. what is known as a "toll oharger", the generation of toll data or the calculation of tP® fees is usually carried out in the formi of a service by » 'service provider"; the service provider must guarantee a cer-ua-in efficiency, fo.r example a certain level of toll .levying a toll route.

In order to rPLeasure the functionality and eff-; i ^-^Giency ot a road toll system, fleets of test vehicles are ' u· u ‘-enrly usea, which for example travel over qiven toll routes in a , spot checK imanner so as to then compare the toll fees accruinq i r· j i , a -. .-n trie central station of the toll charger with the spot check ^ i ^ Journeys. To reduce the staf fine and orqanisational outlay, EP o rrr r. λ i x. 6 65 04 4 alterna--· tively^ proposes that the toll charger Droiripts i v. i i j a - 1 o inaividual onooard units liable to pay a toll fee to collect Position-related data in a spot check manner and to send this as reference data directly to the central toll station of the tol ^ the reference data is compared with the toil uenøI.aL‘dG GuX“ ing operation by the service provider so as to measure i"he efficiency of the road toll sy'^stern.

The objective of the invention is to create devices and methods for function surveillance in a road toll syspgr-p which consequently enable an improvement of the efficiency of the road toll system and thus an increase of the level of toll. levy.ing.

This objective is achieved in accordance with a first aspect of the invention with an onboard unit of the rype mentioned in the introduction, characterized b'y an outage detector connected to the satellite navigation receiver, wdiich outage detector is configured to respond to an absence of position fixes over a given minimum time span or to a drop in quality measureirient values under a given mdnimum quality measurement, and a recorder connected to the satellite navigation receiver and controlled by' the outage detector, which recorder is configured to generate, when the outage detector responds, an error dataset 'With at least the last position fix before the response, •wherein the processor is configured to receive the error dataset from the recorder and to send it 'cia the radio transceiver.

In accordance with a second aspect, the invention creates a method for function measurement in a road toll system with a central station and at least one vehicle-mounted onboard unit, which continuously generates position fixes and associated, qual ity measurement values from satellite raw data and sends toll data based thereupon to the central station, comprising: detecting an absence of position fixes over a given minimum time span or a drop in quality raeasurernent values under a given minimum quality measurement in the onboard unit, and in case of a detection, recording an error dataset wvith at least the last position fix before the detection in the onboard unit, sending the error dataset from the onboard unit to the central station, and evaluating the error dataset in the central station.

In accordance v/ith the invention it is thus possible, for the first time, to make the quality of the GNSS p>osition determination and coverage in the road toll system accessible to a central evaluation facility and to thus determine critical GNSS error locations in the road network in good timLe and to allocate these geographically on the basis of the last position fix. Instead of a mere spot check performance review, position determination errors of GNSS OBUs can be evaluated in the central station immediately or only with a short transmission time delay continuously and - with appropriate distribution of the OBUs -comprehensively covering a large area. As a result, different GNSS-induced errors in the road toll systera, for example interfering signals, shadowing of the satellite signals, etc., and causes thereof, for example local or mobile interfering signal sources ("jarrmers") or geographical conditions, such as mountains or tunnels, can be determined. It is thus possible, for the first time, to introduce targeted measures at the error locations localized in each case by the last position fixes, in order to remedy the error, for example to erect stationary position transmitters, assisting beacons, satellite signal repeaters, or the like, or to identify and switch off interfering sig-n a 1 s o u r c e s, e t c .

It is particularly favourable when the error dataset generated by the onboard unit contains a time stamp of said last position fix. It is thus possible, from a plurality of error datasets of various onboard units or the same onboard unit, at different times of the day or year, to also determine time-dependent er- rors and error causes, ror example interfering signals that change over time or are periodic, unfavourable satellite constellations or shadowing of the satellite signals depending on Weather events or by vegetation during growing seasons, etc. i''urthermo.re, the movement or a rfiobiie interfering signal source can be accurately tracued vv'.rth the aid of traffic cameras and/or emergency vehicles, for example in order to identify "jammers", which deliberately transmit interfering signals so as to prevent correct toll levying.

So as to be able to even better delimit the geographical areas of the detected error, it is particularly advantageous when the error dataset also contains the first position fix generated after the response or detection has finished. Here, the error dataset preferably also contains a time stamp of said first position fix for the aforementioned reasons.

In a favourable embodiment or the invention the error dataset also contains at least one quality measurement value generated v;hen the outage detector responds or during detection of the outage. Error causes can thus be determined even more precisely, 'when the quality' mea surerfient value contains, for example, the number of satellites used to generate the associated position fix or a DOP (dilution of precision) value of the associated position measurement value, an unfavourable satellite constellation - occurring randomly^ or locally frequently - could thus be identified. If the quality measurement value contains, for example, the respective signal levels of the satellites used for qeneration of the associated position measurement value and/or a signal/noise ratio of the satellite signals, then interfering signals or signal damping - for example as a result of local, possibly even movable interfering transmitters or as a result of weather events or shadowing by mountains or forests ~ can also b e d e t e r m i ri e d.

It goes without saying that an error dataset can contain not just one, but also a sequence of cjuaixty measurement values generated as the outacje detector responds, and thus allows conclusions that are even more accurate, for example with regard to possible different error causes.

The error aataset also preferably contains satellite raw data received as the outage detector responds or during detection of the outage and/or sensor measurement values generated in a sensor element, whereby further basic principles for a subsequent determination of possible error causes are created.

It rs part.1 cularry ravourable when the outage detector contain,s a watchdog, which can be triggered anew by each generated position fix. This constitutes a particularly simple, reliable module for the outage detector.

In a further preferred ea-ibodiment of the method according to the invention, at least a second error dataset, generated and sent by a second onboard unit in the specified manner, is received and the error datasets of the at least two onboard units are validated acjainst each other during evaluating. Changes over time of possible error causes can thus be taken into consideration niore easily and individual errors or interferences of individual onboard units, for example as a result of incorrect arrangement in the vehicle, can be compensated for. At the same time, with an increasing number of available onboard units when evaluating the error datasets, the validity of said onboard units with regard to possible error causes also increases.

It is particularly favourable when, during evaluating, geographical interference and shadowing areas of the satellite reception are determined by comparing the error datasets writh a digital map. A "map of GNSS errors" is thus generated, v/hich can be compared with geographical conditions, such as high mountains, narrow valleys, tunnels, etc. In this v/ay, natural error causes can be easily di,stinguished from technical errors causes, and measures for rectifying the errors can be undertaken.

The invention will be explained in greater detail hereinafter on the basis of an exemplary embodiment illustrated in the accorapa-nylng drawings. In the drawings:

Fig. 1 shovis a schematic plan view of a road toll system with vehicle-mounted onboard units according to the invention;

Fig. 2 shows a block d.iagram of one of the onboard units from; Fig. 1; and

Fig. 3 shows exemplary data and signal diagrams wnich occnr j_n the onboard unit from Fig. 2 and as the mernoa o.l. the j-uvenrion is being carried out.

Fig. 1 shows a road toll system 1, which is based on onboard units (OBUs) 2 v/hich are carried by vehicles 3 in order to levy a toll or charge for their uses of certain locations in a network formed by roads 4. The use of a location can be, for example, travel in a certain segment of a road 4, travel beyond a border, residence in a certain geographical area, or the like, and can be billed for In any way, for examp.j.e per .i.oaa segment, dls^'ance travelled, urme spent rn an area (for examp.ι,β park.j.ng time), etc.

According to Fig. 2, each onboard unit 2 has a satellite navigation receiver 5 for this purpose, which continuously determines the position of the onboard unit 2 from satellite signals 6 of navigation satellites 7 (Fig. 1) of a global satellite navigation system ((SNNS) and outputs this as position fixes pi, ..., generally pi, with associated quality measurement values qi, qz, ..., generally qi.

Each quality measurement, value qi of a position fix p, can contain different quality parameters, for example number, signal level and,''or signal/noise ratio of the signals 6 of the navigation satellites 7 used to determine the p)articular position fix Pi, for example also in evaluated form of DOP (dilution of precision) values, as are made availaib.le by commercia-lly conventional satellite navigation receivers 5 for each position fix pi.

In addition to the position fixes p., and quality mieasurement val-ue.s thereof qi, the satellite navigation receiver 5 can also output the "ravi" satellite data fonring the basis thereof, for example sections of the satellite signals 5, or can output processing data fornaed during the course of generation of the position fixes Pi, referred to hereinafter as "satellite raw data" r;. The position fixes pi, quality measurement values qi, and satellite raw data ri can be output here at separate outputs of the satellite navigation receiver 5, at a common output in multiplexing, or on a common bus in separate data packets.

The onboard unit 2 is also provided with a radio transceiver 3, for example in accordance with a 2G, 3G, 4G or 5G mobile radio standard such as GSM, UMTS or LTE, the 1TS--G5 or WAVE standard for short-range radio communication, one of the IEEE 802.11 standards for WLAIJ comiaunication, or the like, and a processor 9 connected to the satellite navigation receiver 5 and the radio transceiver 3.

One or more sensor elements 10, for example speed or acceleration sensors, can optionally also be provided, which can be arranged in the onboard unit 2 itself or connected to the onboard unit 2 - in the vehicle 3 and generate sensor measurement values m,, for example speed or acceleration measurement values or location measurement values approximated therefrom,. A sensor element 10 of this type can also be formed. bA/ the radio transceiver 8, in which case the sensor measurement values mi are mietadata of the radio transceiver 8, for example radio cell or reception field strencjth data o.f a radio link 11 to a radio station 12, here a base station of a m.obi.le network in which the radio transceiver 8 is located.

The processor 9 generates toll data M from the sequence {pi} of position fixes pi so as to transmit this data v;ith the aid of the radio transceiver 8 via the radio link 11 and the radio station 12 to a central station 13 of the road toil sy'-stem 1.

The toll data M can be, for example, toll fees, which are generated by' map-matching the position fix sequence {pi} with a digital mLap, stored in the onboard unit 2, of roads 4 or locations subject to a toll fee. Alternatively', the toll data M could also be the position fixes pi themselves, which are sent individually or - filtered according to quality^ if desired - combined in a bundle at any or given moments in time, in accordance with given paths or simply with availabilit’/ of a radio link 11 via the ra-d.i.o transceiver 8. In the latter case, map matching and fee calculation can be performed for example in the central station 13. In accordance with Fig. 1, the vehicles 3 are travelling over their respectiv'e routes on the roads 4 through a geographical area i4 in which the satellite signals 6 recei'ved by' the satellite navigation receivers 5 are disrupited or shadowed, such that the quality measurement values qi drop and/or the satellite navigation receivers 5 do not generate any position fixes pji.

Fig. 3 shows, by way of example, time curves of the signals or data of an onboard unit 2. In accordance v/ith this example the satellite navigation receiver 5 generates, at each of the moments ti, t-2, ..., generally ti, a position fix p;. (F'icj. 3a) and Sin associated quality measurement value q: (Fig. 3c) from the satellite ravi data ri (not illustrated) . If the vehicle 3 travels through the specified geographical area 14, the satellite navigation receiver 5 does not generate any' position fixes pi over a period of time e, but generally still generates quality measurement values q.i.

In order to be able to sense and measure errors of the position determination of the onboard unit 2 and therefore the toll-levying function of the road toll system 1, for example as a result of signal interferences and/or shadowing of the satellite signals 6, the follov/ing components and methods are used.

The onboard unit 2 for this purpose has an outage detector 15 connected to t(ne satellite navigation receiver 5, which outage detector responds and generates an output signal s (Fig, 3e) , for example a logic "high" signal or a logic "1", when it either (a) detects the absence of position fixes pi over a given lainimum tiiTLe span (δ) and/or (b) a drop in quality measurement values qi under a given minimum quality measure Onm·

In order to detect the event (a) , the outage detector 15 can comprise a watchdog 16, for example in the form of a dead man^s or retriggerable monostable multivibrator circuit, which is triggered anew by each new position fix pi at its input for the minimum time span δ and thus outputs a detection signal d (Fig. 3b) at its (here: inverted) output when no new position fix pi arrives within the spiecified miniiruim timie span δ.

Alternatively or additionally to the -watchdog 16, the outage detector 15 can have a comparator 17 for detection of the event (b) , which comparator compares the incoming quality measurement values qi with a minimum quality measure and, if the quality measurement values qi drops under the mininmni quality measure

Wmin, outputs an output signal c (Fig. 3d) , Depending on the complexity of the quality rrieasurement values qi, it could be desirable tor simplification of this comparison for the comparator 17 firstly to combine a quality measurement value qi containing a plurality of parameters (dimensions) into a single global quali-cy iTieasure Qi; alternatively, the niinimum quality measure Qmir. could comprise separate individual threshold values for a plurality of quality piaramÆters contained in a quality measurement value q.i. I he output signals c or the watchdog 16 and d of the comparator 17 can be linked to the output signal s of the outage detector 15, for example by a simple OR circuit 18, Instead of the OR circuit. 18, a complex evaluation logic, wh.ich for example also takes into consideration the time behaviour of the signals c and d, can also be provided. If the outage detector 15 contains only one of the components from, the watchdog 16 or comparator 17, the c.ircuit i8 .is omitted and. the outpur. s.igna.! .s co.inc.ides w.ith the signal c or d.

The output signal s generated by the outage detector 15 controls a .reco.rde.r 19, v/h.ich, in the case of the specified events (a) and/or (b) , generates an error dataset F and provides this for the processor 9 for transmission via the radio transceiver 8 to the central station 13. As shown symbolically in Fig. 2, the recorder 19 is, for example, a recording unit 20, which has a -bul.fe.!:' rri0iiLO.ry 2.i. and wh.ich is connecued to one or more outputs of the satellite navigation receiver 5.

As error dataset F, the recorder 19 in the simplest case records the .13.5 0 pos.ition f.ix pj,, generaoed. by the .satellite navigat.ion receiver 5 just before the response of the outage detector 15; see Fig. 3a. in addition, the recorder 19 can also add further data to the error dataset F depending on requiremients, such that this error dataset can also contain - individually or in any combination: - a time stamp t.,^ of the aforementioned last position fix p^; che f,irst pos-iticn f.ix pn gønø.ratøG direct,ly a.fter the .respond— ing oil the outage detector 15 has finished, i.f desired also with associated tirae stamp - the quality measurement values qm and/or q, generated with the specified last and/or first position measurement value ρκ, pr,; one or more of the quality measurement values q± generated during the responding of the outage detector 15, i.e. provided the recorder 19 is actuated (s "1"), if desired also with associated time stamp ti; - the satellite ravi data r; received - or formed - with the specified last and/or first position rrieasurement value p,„, Pn and/or during the responding of the outage detector 15 (s = "I"); and/or - the sensor measurement values m-; generated approximately at the same time as the specified last and/or first position measurement value Pm, Pn and/or during the responding of the outage detector 15 (s - "1").

The recorder 19 can optionally pre-process the error dataset F, for example by eliminating redundant or irrelevant data, adding environmental data from the surroundings of the onboard unit 2 or internal state data of the onboard unit 2, data summary, etc., depending on the particular situation.

The received error datasets F are evaluated in the central station 13. This evaluation can be performed on the one hand individually, i.e. the error datasets F of an onboard unit 2 are considered individually, and on the other hand a plurality of error datasets F of different onboard units 2 can also be received, evaluated jointly, and validated, for example against one another.

When evaluating, the error datasets F are considered depenarng on the location of the position fixes specified therein pr,, Pr,, {pj:} and, v/hen sensed, time stamps tn,, t,., {t-;}, quality imeasure-ment values Pn,, q,i, {qi}» satellite rav/ data jri} and/or sensor measurement values {m.i} thereof and are analysed for possible error sources so as to prepare measures for remedying these. When evaluating, geographical interference and shadowing areas 14 of the satellite reception as v/ell as, where applicable, the time dependency thereof can oPt.ronally be deterimined by a comparison of the error datasets F with a digital map. Permanent shadowing, for example by tunnels, can thus be identified and distinguished from temporary shadov/ing, for example in narrow valleys, vihere a sufficient number of satellite signals 6 can, only sometimes, be received in the necessary strength, or from weather induced signal attenuations, or shadowing, dependent on the time of year, in dense vegetation of fixed or movable interfering sources ("jammers"), and so on. Consequently, targeted mieasures for rem··· edging errors can be introduced in order to increase the level of toll levying of the road toll system 1, for example stationary position transmitters or satellite signal repeaters can be erected, or interference sources can be elirtiinated or switched off, or deliberate transmission of interfering signals by jammers can be tracked and prosecuted.

The invention is not limited to the presented emibodiments, but includes all variants and modifications that fall within the scope of the accompanying claimLS. The onboard unit 2, as a whole or individual comiponents thereof, such as the outage detector 15, the recorder 19, or parts thereof, can thus be implemented, for example in the processor 9, both as hardware modules and as software objects.

Claims (15)

ONBOARD DEVICE AND PROCEDURE FOR FUNCTION MONITORING IN A ROAD CARE SYSTEM 1. Onboard unit ill a road fee system (1) with a satellite navigation imaging modifier (5) for the continuous generation of position fix points (pi) and associated quasi-measurement values (qi) on the basis of sate 11 li raw data (n), a radio transmitter (8) and one these components (5, 8) cobia processor (9) configured for ten! generating fee data (M) on the basis of the position fix points (pi) and transmit thereon via the radio transceiver (8), characterized by a cube error detector (15) configured to respond to a failure of position fix points (p), to the satellite navigation receiver (5) over a certain minimum time interval (δ), a decrease in quality gull values (qi) results in a certain minimum quality gutter! (Qmin), and a ten! the satellite navigation receiver (5) switched on and controlled by the fault detector (15), the registrar (19) configured to generate a fault data block (F) with at least the last position fix point (pm) before the error message when the processor detects, (9) is configured ten! receiving the error data record (F) from the registrar (19) and transmitting it via the radio transceiver (8). An onboard device according to claim 1, characterized in that the error data block (F) also contains a timestamp (tm) for said last position fix point (pm). An onboard device according to claim 1 or 2, characterized in that the error data bin (F) also contains the first position fixing point (pn) generated after the failure of the fault situation. An onboard device according to claim 3, characterized in that the error data bin (F) also contains a timestamp (tn) for said first position fix point (pn). Onboard device according to one of claims 1 to 4, characterized in that the error data block (F) also contains at least one quality measurement value (qi) generated during the fault situation. An onboard unit according to one of claims 1 to 5, characterized in that the error data block (F) also contains in the error situation received satellite wire data (n) and / or sensor in a sensor element (10) sensor measurement values (mi). An onboard device according to one of claims 1 to 6, characterized in that the fault detector (15) contains a "watchdog" (16) which can be reactivated by each generated position fix point (pi). A method of feature monitoring in a road fee system (1) with a central (13) and at least one vehicle-borne onboard unit (2) that continuously generates position fix points (pi) and associated quality measurement values (qi) on the basis of satellite data (n) and then sends based fee data (M) to the switchboard (13), comprising: detecting a failure of position fit points (pi) over a specified minimum period (δ) or a decrease in quality measurement values (qi) below a specified minimum quality target (Qmin) in the onboard the device (2), in case of detection, an error data block (F) is recorded with at least the last position fix point (pm) before the detection in the onboard device (2), sending the error data block (F) from the onboard device (2) to the control panel (13), and analysis of the error data block (F) in the control panel (13). Method according to claim 8, characterized in that the error data block (F) also contains a timestamp (tm) for said last position fix point (pm). Method according to claim 8 or 9, characterized in that the error data block (F) also contains the first position fix point (pn) generated after the detection has ended. Method according to claim 10, characterized in that the error data block (F) also contains a timestamp (tn) for said first position fix point (pn). Method according to one of claims 8 to 11, characterized in that the error data block (F) also contains at least one quality measurement value (qj) generated during the detection. Method according to one of claims 8 to 12, characterized in that the error data block (F) also contains during the detection received satellite wire data (n) and / or in a sensor element (10) sensor measurement values (mi). Method according to one of claims 8 to 10. 13, characterized in that at least one other is received in the control panel (13) by another onboard unit (2) in the said manner produced and sent error data bin (F), and the error data blocks (F) from the at least two onboard units ( 2) validated by evaluating them against each other. Method according to one of claims 8 to 10. 14, characterized in that, by analyzing through a comparison of the error blocks (F) with a digital map, geographical disturbance and shadow areas (14) are determined in the satellite reception.