DE102012222334A1 - Method and device for determining the relative distance and the relative movement of several road users - Google Patents

Abstract

The present invention relates to a method for determining the relative distance and / or the relative movement between at least two road users, in particular between at least two vehicles, with the reception of acoustic signals originating from initialization transmissions in the form of acoustic signals from a first Road users were sent out, reaction transmissions are triggered by a second road user in the form of acoustic signals, which are received and evaluated by the first road user. The reaction transmissions of the second road user are made after the expiry of at least one delay time known to the road users, which is set so long that acoustic signals received by the first road user that originate from passive reflections of the initialization transmissions of the first road user at surrounding objects have no influence on a have carried out by the first road user evaluation of the reaction transmissions of the second road user received by means of at least one receiver.

Description

Field of the invention

The present invention relates to a method for determining the relative distance and / or the relative movement of at least two road users, in particular at least two vehicles, in which based on the initialization of acoustic signals generated by a first road user of the two road users reaction emissions of acoustic signals of the acoustic signals the initialization transmissions receiving second road user are triggered and received by the first road user and evaluated. Furthermore, the invention relates to a corresponding device for determining the relative distance and / or the relative movement between at least two road users, in particular between at least two vehicles. The invention also relates to a vehicle assistance system with a corresponding device.

State of the art

To acoustically detect the environment of vehicles, in particular currently pulsed-measuring systems that operate in the ultrasonic range are usually used. In this case, typically every 10 ms to 300 ms via an electro-acoustic transducer acoustic pulses emitted at about 50 kHz. From the pulse transit time to the transmitting and non-transmitting transducers, the object distance in space is inferred.

In Applicant's earlier patent applications, it has been proposed not to limit ultrasound to 50 kHz in the selection of the acoustic medium. The decision 30 years ago for the ultrasonic range was partly due to the fact that in this frequency range, the noise power proportional to the reciprocal of the signal frequency decreases sufficiently strong, and on the other hand, the attenuation caused by the medium is still within manageable limits, and that was the first affordable electronic Components for this frequency range came up.

The technology has evolved since then: cars are quieter, the problems of electromagnetic compatibility (EMC) more manageable, and with the signal processing available today in any MP3 player (MP3 player), a more efficient filtering in an affordable frame possible.

In particular, with the introduction of electric vehicles, it is now necessary for these vehicles to be acoustically noticeable through synthesized sound in order to at least warn traffic lights or other road users. In older patent applications of the Applicant has therefore been proposed, the entire frequency spectrum of the ultrasonic range with the human auditory system as a whole for the acoustic monitoring of a vehicle environment by evaluating the sound emitted by the vehicle itself, in particular by evaluating the emitted from the vehicle synthesized sound and / or the function of the vehicle itself generated sound to use for the detection of signalers or sound sources and thus for increasing traffic safety.

The document DE 30 24 791 C2 describes a device for monitoring the position of a working ship, where it is described as the prior art that in a known solution on the underside of a drill ship with spaced apart four microphones are mounted, while at a certain point near the well at the bottom of an acoustic transponder is arranged. This acoustic transponder is controlled by an acoustic transmitter on the underside of the ship and thus in turn causes the emission of acoustic signals. The acoustic signals emanating from a single point on the water bottom are picked up by three microphones corresponding to the respective position of the ship with a larger or smaller phase shift, which is processed in a computer, whereby the position of the ship can be corrected.

In the documents DT 23 35 613 A1 and DT 23 35 613 B2 A method is described for measuring distances, changes in distance and / or changes in speed of relatively moving objects, in particular for vehicles of all kinds. In this case, the acoustic signal emitted by the transmitter of a first object is received by the receiver of a second object, changed in its frequency position, and then directly actively reflected in order to be received by the receiver of the first object. Particularly suitable for the application of the measuring method in land and water vehicles, the use of acoustic radiation, in particular of ultrasound, is mentioned. The distance between two vehicles is thus determined on the basis of a transit time evaluation and the relative speed from the Doppler shift. It is further stated that information can be modulated on the signals.

In summary, it is known from the prior art to determine the relative distance and / or the relative movement between at least two objects of a first Object of the two objects Initialisierungsaussendungen of acoustic signals to be generated, which are received by a second object of the two objects and recognized by an evaluation as such. Further, it is known in the art to generate response emissions of acoustic signals of the second article in direct response to the received acoustic signals of the initialization transmissions. In this case, the acoustic signals of the reaction emissions of the second object are received by the first object and evaluated to determine the relative distance and / or the relative movement between the two objects.

A disadvantage of the realization of classical transponder methods in the sonic or ultrasonic range is the low propagation speed of the sound or ultrasound in comparison to the transmission by means of electromagnetic waves. Thus, classical acoustic transponders already begin to emit reaction emissions while the initialization transmissions have not yet fully arrived. In addition to this temporal collision, which occurs in such a transponder method, there are also temporal collisions with echoes of passively reflecting objects. A disadvantage is the high implementation cost, which is required in an evaluation of the received acoustic signals of the reaction emissions because of the same or quasi-simultaneous incoming received echo signals derived from passive reflections of the acoustic signals of Initialisierungsaussendungen to surrounding objects. In normal road traffic, several road users use one and the same transmission medium. The required effort increases if several road users in one and the same medium are to generate reaction emissions to one and the same initialization transmission. A further disadvantage is when each electro-acoustic transducer, which is located on a road user, responds in the same way to the arrival of each Initialisierungsaussendung.

A disadvantage of conventional transponder method is further that they are suitable only for a few forms of initialization signals. Interoperability between different acoustic transponder methods is often not possible and the use of new technology, such as more complex modulation methods, is not supported by existing transponders. On public roads, however, meet various road users whose equipment is often very different.

Disclosure of the invention

According to the invention, a method is provided for determining the relative distance and / or the relative movement between at least two road users, in particular between at least two vehicles, in which the reception of acoustic signals originating from initialization transmissions in the form of acoustic signals from a first road users were sent by a second road user reaction emissions in the form of acoustic signals are triggered, which are received and evaluated by the first road user. In this case, the reaction emissions of the second road user after the expiration of at least one known to the road users delay time is made, which is set so long that received from the first road user acoustic signals derived from passive reflections of Initialisierungsaussendungen the first road user to surrounding objects, no effect on a made by the first road user evaluation of received by at least one receiver reaction emissions of the second road user have.

Furthermore, according to the invention, a device is provided for determining the relative distance and / or the relative movement between at least two road users, in particular between at least two vehicles, which is designed to initiate the initialization of acoustic signals generated by at least one road user of the two road users by means of at least one Receive receiver and recognize by means of an evaluation as such and to generate in response to the received Initialisierungsaussendungen the at least one road user reaction emissions of acoustic signals. Furthermore, the device is further configured to generate the reaction emissions of acoustic signals with a predetermined signal duration after the expiration of at least one predetermined delay time known to the road users.

The dependent claims show preferred developments of the invention.

In the method according to the invention, in particular based on the received from the first road user acoustic signals of the Rektionsaussendungen the second road users reaction emissions of acoustic signals of the first road user after the expiration of at least one known to the road users delay time. This delay time is set so long, that the acoustic signals received by the second road user, which originate from passive reflections of the acoustic signals of the reaction responses of the first road user to surrounding objects, have no influence on one of the second road user to determine the relative distance and / or the relative movement between the two road users carried out Evaluation of the received by the second road user by means of at least one receiver acoustic signals of the reaction emissions of the first road user.

In other words, such generated on the receipt of an initialization Ausausendung reaction emissions and optionally also in response to the reception of reaction emissions generated further reaction emissions of at least one road user, the acoustic signals of actively generated emissions (Initialisierungsaussendungen and / or reaction emissions) of at least one other road user and optionally receives a sound source existing in the acoustic environment and recognizes, in each case after the expiry of a fixed and known to the appropriate road users delay time is emitted.

Due to the use of the fixed delay time known to at least the involved road users, collisions of reaction emissions or of further reaction emissions of such road users can occur only, which are located at the same distance to the road users generating the actively generated emissions of acoustic signals.

If several road users are present in the traffic, the reaction emissions or the further reaction emissions of acoustic signals in response to the actively generated emissions of this generating traffic participant or the sound source after the expiration of a fixed, at least the participating road users known and in particular each different delay time generated become.

By using a fixed, at least the involved road users known and each different delay time, collisions of reaction emissions of such road users can be avoided in a simple manner, which are located at the same distance from the actively generated emissions from acoustic signals generating road users. In other words, it is achieved by the pseudorandom use of a different delay time from a set of a known to all road users amount of significantly different delay times that the probability of collision of the reaction emissions and the same time in a running distance road users decreases statistically.

By using a fixed delay time known to at least the road users involved, the road user who initiated the actively generated emissions of acoustic signals may be identified as being between the time of origin of his actively generated emissions and the time of receipt of the acoustic signals as Reply to the received acoustic signals of the actively generated emissions generated reaction emissions of the other road users on the distance between the two road users at the moment of signal exchange close.

According to the invention, fixed delay times are used, which are so long that all echoes from potentially far away passively reflecting objects from the environment are already closer to the receiving road user. As a result, collisions of the acoustic signals of the corresponding reaction emissions with echoes of passively reflective environmental objects are easily reduced to a minimum. Due to the fact that during an evaluation according to the invention of the received acoustic signals of the reaction emissions, no further evaluation of simultaneously or quasi-simultaneously received echoes of passively reflective environmental objects has to take place, the implementation effort of a corresponding evaluation unit required in the inventive evaluation of the acoustic signals of the reaction emissions is considerably reduced.

By using the delay times according to the invention, the noise-quiet problem (loud reaction emissions compared to quiet echoes of the passive reflections) is also defused. In this case, the corresponding evaluation units of the road users, who receive the acoustic signals of the initialization emissions or reaction emissions of other road users, are initially adjusted for the reception of quiet echoes which originate from passive reflections of the acoustic signals of these initialization emissions or reaction emissions. The same evaluation units can then further, if no more echoes occur, that is, after the expiry of the delay times according to the invention, on the reception of loud acoustic signals in response to the received acoustic signals of the initialization emissions generated reaction emissions or on the receipt of loud acoustic signals of the reaction generated in response to the received acoustic signals of the reaction emissions further reaction emissions. Thus, the probability of detection of both quiet echoes and loud reaction emissions is increased, so that the aforementioned noise-quiet problem can be significantly mitigated.

According to the invention, a method is thus provided for determining the position and / or the movement of actively active road users and / or optionally also of passively reflecting objects in the vicinity of movement aids by means of acoustic signals. The movement aids can be designed, for example, as wheelchairs, Segways, bicycles, electric cars, other vehicles such as cars, buses and trucks (trucks). In this case, the operators of the movement aid and / or other road users are informed or warned in particular by means of acoustic and / or optical signals about the traffic situation. In the method according to the invention, furthermore, the intended spatial movement, such as, for example, the speed profile with respect to a coordinate system, can be influenced automatically by braking, accelerating and steering, at least in a supportive manner. Also, devices that reduce the consequences of improper movement in traffic, especially accidents, such as belt tensioners, windows, airbags and / or adjusting devices for hoods can be influenced or activated in their functioning. In particular, at least one acoustically active road user recognizes at least one characteristic feature of the acoustically generated acoustical signals of the initialization transmissions of at least one other acoustically active road user and / or at least one other sound source located in the surroundings of the acoustically active road users and subsequently transmits after a delay time for a limited time, an acoustic response broadcast preferably having a unique relationship with the initialization broadcast. In this case, at least one characteristic feature such as the signal strength and / or the time course of the signal strength (for example in the form of a pulse pattern) and / or the time course of the signal frequency or the signal frequency mixture is used. Optionally, the road user who has sent out the initialization message responds to the receipt of at least one reaction message in the same way by emitting another reaction message. Both the traffic-actively emitting road users and those road users who only receive and evaluate the acoustic signals occurring in the environment, both for determining the position and / or the movement of actively transmitting road users and / or passive reflective objects from the environment emitted Initialisierungsaussendungen the emitted reaction emissions and optionally also the emitted and generated in response to the receipt of reaction emissions further reaction emissions and the case each resulting echoes of passive reflective objects use.

Preferably, in at least one evaluation of the acoustic signals of the initializing emissions of an initialising road user and / or of the reaction emissions of at least one of the two road users carried out to determine the relative distance and / or the relative movement between at least two road users, at least one characteristic feature of the acoustic signals of these initialization emissions and / or these reaction emissions, such as preferably the signal strength and / or the time course of the signal strength (for example in the form of a pulse pattern) and / or the signal frequency and / or the time course of the signal frequency or the signal frequency mixture of the corresponding acoustic signals used.

In the method according to the invention, the road user generating the initialization transmissions is also aware of the delay time between the time at which the at least one characteristic of the acoustic signals of his initialization transmissions and the start of the reaction transmissions of the traffic participants receiving the acoustic signals of the initialisation transmissions are complied with. Thus, the initializing road user from the total duration of the acoustic signals of Initialisierungsaussendungen and the corresponding reaction emissions on the distance between the two road users conclude.

In order to reduce the probability of collision between the reaction emissions of several road users reacting in particular to the same emissions of a road user, it is preferable to use a few different delay times (delays) from a set of agreed delay times for these reaction emissions.

To reduce the probability of collision of the acoustic signals of the reaction emissions of several road users, is in a particularly advantageous embodiment of the According to the invention, the signal duration of the acoustic signals of the reaction emissions of at least one road user is less than a predetermined fraction of the signal duration of the acoustic signals of the initializing emissions of the initialising road user (first road user). In particular, at least one signal duration and / or at least one frequency or at least one frequency response of the acoustic signals of the reaction emissions of at least one road user is / are at least known to the road users receiving the acoustic signals of these reaction emissions.

In other words, in particular in the case of permanent fulfillment of at least one characteristic feature of the acoustic signals of the initialization emissions of a road user, only temporary reaction emissions of acoustic signals are generated by the receiving road users. In particular, the proportionate transmission duration of such reaction emissions may be less than 1%. For example, if the characteristic feature of the acoustic signals of an initialization transmission to be fulfilled is the signal strength, then a continuous sound source generating the initialization transmission can effect a reaction transmission comprising an occasional short-term replay of the continuous sound source.

In order to achieve a further reduction in the probability of collision between the reaction emissions of several road users reacting in particular to the same emissions of a road user, it is preferable to use a few different reaction emission times from a set of agreed reaction emission durations (replay durations) for these reaction emissions.

In a further preferred embodiment of the method according to the invention, information relating to these reaction emissions is modulated in the acoustic signals of the reaction emissions of at least one road user, in particular information comprising the delay time used for these reaction emissions and / or the signal duration and / or the signal frequency or the signal frequency characteristic corresponding acoustic signals.

In a particularly preferred embodiment of the method according to the invention, the acoustic signals of the reaction emissions of at least one road user have a clear relationship to the initialisation emissions of the initialising road user. The signal strength and / or the signal course of the acoustic signals of the reaction emissions of at least one road user preferably has a clear relationship to the signal strength and / or to the signal curve of the initialization traffic signals of the initializing traffic participant, which in particular have a time-variable frequency response.

In this case, the acoustic signals of the reaction transmissions preferably each comprise a predetermined signal excerpt of the acoustic signals of the initialization transmissions, the predetermined signal excerpts being displayed in inverse time order (or "playing backwards" colloquially) or in unaltered chronological order at the same playback speed and / or at a different playback speed (FIG. The changed playback speed is realized, in particular, by the use of a sampled rate which is changed in comparison with recording, The advantage of using a different playback speed for the acoustic signals of the reaction transmissions is that that the acoustic signals of the reaction emissions from the acoustic signals of the Initialisierungsaussend technically easily separable by filtering. In particular, a signal form determined by coding is used for the signal form of the acoustic signals of the reaction emissions, which is realized for example by means of an assignment table or by an algebra.

In order to easily separate the acoustic signals of the reaction emissions of a plurality of road users reacting in particular to the same emissions of a road user, some different ones of a set of agreed playback speeds are used for the playback speeds of the acoustic signals of these reaction emissions.

In order to achieve a further reduction in the probability of collision between the reaction emissions of a plurality of road users reacting in particular to the same emissions of a road user, preferably the delay time, the proportionate transmission duration, the reaction transmission duration, the strength of the signal, the playback sequence, and / or the playback speed depend on the degree of utilization of the acoustic medium by other road users and / or by other sound sources and / or depending on the intrinsic speed of the sending road user and / or the relative position and / or or varied by the relative movement of other objects and / or road users.

In the method according to the invention, at least one receiving road user picks up the acoustic signals of the active emissions of at least one other road user preferably by means of at least two receiving systems and evaluates the differences in the received acoustic signals of the active emissions with respect to relative position and / or relative movement, in particular on the basis of the transit time differences Doppler shift, and / or signal strength off. In addition, this road user can preferably also evaluate the echoes that arrive at him, that is to say also the acoustic signals that have arisen after acoustic emissions due to passive reflection on reflecting objects. At least the spatial relationship between the transmitting and receiving road users and / or the passive sound-reflecting objects is determined from the signal changes during the transmission path and / or a statement is made about the relative movement between the road users and / or the passive sound-reflecting objects and / or on the Traffic conditions between the road users, in particular the position and / or the shape of the intervening other road users or stationary objects, such as trees, and / or on the road condition, etc. inferred.

In particular, each road user can both make initialization transmissions of acoustic signals and govern with reaction emissions of acoustic signals to the received acoustic signals of active emissions of other road users.

The invention also provides a vehicle assistance system having a device according to the invention for determining the relative distance and / or the relative movement between at least two road users, in particular between at least two vehicles.

Brief description of the drawings

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawings:

1 a schematic representation of a traffic situation in which a first, initializing road users Initialisierungsaussendungen of acoustic signals generated, which in turn triggers reaction emissions of acoustic signals in a second, the acoustic signals of the initialization transmissions receiving road users,

2 a schematic representation of the position of the possible Doppler band of the acoustic signals of a reaction emission of a responding road user compared to the position of the Doppler band of the original acoustic signals of the Initialisierungsaussendung the initializing road user for a 1.5 times the recording speed playback speed.

Embodiments of the invention

1 illustrates the inventive method (Autoreplay Protocol) exemplified for a traffic situation in which only two road users T1 and T2 are represented by many possible acoustically active road users. The first traffic participant T1 comprises a signal generator 10 for generating acoustic signals 11 , a transmitting device 20 for emitting acoustic signals, a receiving device 30 for receiving acoustic signals 31 , as well as at least one evaluation device 40 for evaluating the received acoustic signals 31 ,

The second road user T2 comprises the device according to the invention 100 with at least one receiving device 50 for receiving acoustic signals 51 , a transmitting device 60 for emitting acoustic signals, as well as at least one control device 70 for detecting the incoming acoustic signals 51 based on the acoustic signals 51 characterizing features and for causing the emission of acoustic signals 71 as a result of the signals received 51 after a delay TD. The control device 70 is in particular designed such that the generated by the second road user T2 acoustic signals 71 in response to the second road user T2 on the received and generated by the first road users T1 or an ambient acoustic signal source acoustic signals 51 and distinct from the first participant T1 distinct from the classical echoes of passively reflecting objects and thereby as reaction transmissions 71 of the second road user T2, on the active emissions of acoustic signals 11 detected by the first road user T1.

Optionally, the road user T1, who is the original Initialisierungsaussendung 11 had generated a control device (not shown), which depends on the means of receiver 30 received signals 31 According to the invention, further reaction emissions (not shown) are generated which are likewise received and evaluated by the road users present in the environment, such as road users T2. Also, the generated further Rektionsaussendungen preferably with further received acoustic signals and / or with other via other media exchanged signals that characterize the presence and movement behavior of other road users and / or passively reflecting objects, are connected by means of sensor data fusion.

Further, in addition to the first road user T1 and the second road user T2 an evaluation (not shown) for the evaluation by the receiving device 50 received acoustic signals 51 exhibit. Hatched represents the sound medium 80 via which the acoustically communicating road users T1, T2 are connected to one another.

In the 1 TP1 is the pulse duration of the first traffic participant T1 by means of the transmitting device 20 emitted acoustic signals 11 characterized. T12 indicates the time required to transmit the acoustic signal 11 of the first traffic participant T1 until the beginning of the recognition of the second traffic participant T2 by the control device 70 is required. Further, with TP1, the pulse duration of the first road user T1 or an equivalent signal source (not shown) by means of the transmitting device 20 emitted and by means of the receiving device 50 the second road user T2 received acoustic signals 51 characterized. With TP2 is still the pulse duration of the control device 70 of the second road user T2 in response to the received acoustic signals 51 the emissions of the first road user T1 generated acoustic signals 71 characterized. With TD the delay time is marked, which is between the beginning of the detection of the first road user T1 by means of the transmitting device 20 emitted and from the second road user T2 by means of the receiving device 50 received acoustic signals 51 and the triggering of the reaction emissions of the acoustic signals 71 of the second road user T2 passes. Furthermore, the reference character T21 designates the time that elapses between the start of the transmission of the acoustic signals generated by the second road user T2 71 until the beginning of the reception by means of the receiving device 30 of the first road user T1 passes. The pulse duration of the emitted by the second road user T2 and by means of the receiving device 30 the first road user T1 received acoustic signals 31 is marked with TP21.

In a preferred embodiment, the control device controls 70 based on the received signals 51 the emission of the reaction emissions 71 based on characteristics of the received signals 51 Initialisierungsaussendungen, such as the signal strength, the timing of the signal strength (for example in the form of a pulse pattern) and / or the time course of the signal frequency or the signal frequency mixture. In a preferred further developed embodiment, the optionally additionally present control device (not shown) may be configured to receive further reaction transmissions (not shown) of the traffic participant T1, which originally initiated the initialization transmissions 11 generated in response to the receipt of the acoustic signals evaluated by characteristic features 31 the reaction emissions 71 to create. Due to the equivalence to the previous preferred embodiment with respect to the control device 70 will not be discussed separately in the following on the said more advanced expression with respect to the additional control device (not shown).

The initialization signals 11 Optionally, they can not originate from the road user T1, but from another sound source located in the acoustic environment. Also, the initialization signals 11 function-related sound, such as engine noise or the squealing of brakes, or other acoustic signals, such as the beeping of traffic lights, footsteps or driving noise, sounds of fans on buildings, construction noise include.

In a preferred embodiment, the controllers are 70 and / or the optional additionally present control devices preferably designed to the duration TP1 or TP2 of the emitted acoustic signals 11 . 71 and / or the frequency with which the acoustic signals 11 . 71 be sent out, for example, even if the characteristics of received acoustic signals 31 . 51 longer time or even permanently fulfilled. The advantage here is that the sound medium 80 is used only proportionately, and thus the probability of collision with acoustic signals that come from emissions of other active sending road users, and / or echoes that arise as a result of reflections of acoustic signals to passively reflecting objects decreases. So far, the ratio of transmission duration to transmission pauses of 1% has proven itself. If many road users T1, T2 one and the same sound medium 80 use, so included the many, between the road users T1, T2 exchanged acoustic signals 31 . 51 as well as the associated echoes so many, mostly redundant information that a reliable environment monitoring is possible even at a ratio of transmission durations to transmission pauses per electro-acoustic transducer from well below 1% to below 0.1%. Even with only slowly changing scenes, as they are common, for example, during slow driving into a parking space, usually enough a small frequency of transmission. At high speeds and especially when only a few acoustically active road users T1, T2 the medium 80 acoustically sounded, but also a greater frequency of acoustic emissions, in particular such electro-acoustic transducers (not shown separately), whose orientation is predominantly along the expected route, makes sense. This is especially true if a division of the sound medium 80 For example, by frequency, code and / or signal strength multiplex is possible. Under these circumstances, a transmission frequency per electro-acoustic transducer of more than 10% may be useful.

In a very preferred embodiment, the delay time TD is between the beginning of the arrival of an initialization signal 51 and the beginning of emission of a response signal 71 regardless of the signal strength and independent of a signal change due to a Doppler shift. Furthermore, this delay time TD is known to all road users T1, T2 who use the acoustic emissions in accordance with this method or autoreplay protocol for determining the position and / or movement of other road users T2, T1. In this way, every road user T1, T2, the in the sound medium 80 exchanged acoustic signals, from the signal propagation times, in particular between a Initialisierungsaussendung 11 and a reaction message 71 if only two acoustically active road users T1, T2 in the sound medium 80 or from the signal propagation times between reaction emissions 71 when in the sound medium 80 more than two acoustically active road users T1, T2 are located on the spatial relationships between the acoustically active road users T1, T2 and / or between the passive reflecting objects (not shown) located in the scarf medium 80 to conclude.

In a further preferred embodiment, the signal strength of the initialization transmission at least on the main acoustic beam direction of an electro-acoustic transducer has a fixed value or a plurality of signal strength values which are clearly distinguishable and known to all road users T1, T2.

The directional characteristic here is the spatial distribution of the signal strength with respect to the electro-acoustic transducer. In a further preferred embodiment, the directional characteristic of a sending road user T1, T2 is known to at least one receiving road user T2, T1. This is achieved, for example, in that all electroacoustic transducers (not shown separately) use the same directional characteristic, or else that in the exchanged messages, in particular in the exchanged acoustic messages, the information about the used directional characteristic of the transmitting electroacoustics Transducer (not shown separately) and / or transmitted via the transmitted signal strength.

In a further preferred embodiment, the ratio of the signal strength of the received signals changes 51 the initialization transmissions and the received acoustic signals 31 the associated reaction emission 71 and / or another in response to a received response message 71 generated reaction (not shown) by rules that are known at least some road users T1, T2. Furthermore, this ratio preferably changes independently of the signal change due to a Doppler shift. Furthermore, in the Reaktionsaussendungen 71 prefers information about the strength of the received signal 51 contain the initialization transmissions. In a preferred embodiment, the ratio between the signal strengths of the initialization broadcast 11 and the respective associated reaction emission 71 or the other in response to received Reaktionsaussendungen 71 generated reaction emissions (not shown). With this implementation variant, the probability of collision of the reaction emissions decreases 71 with decrease in the signal strength of the received acoustic signals 51 the initialization transmission, and in the reception signal of the traffic participant T1, the initialization transmission 11 had radiated the influence of the transmission loss between the two road users T1, T2 is already contained square as information.

In an alternative implementation variant, the reaction emission 71 always sent with the highest possible signal strength. The probability of collision of the reaction emissions 71 is determined by the signal strength of the received acoustic signals 51 the initialization transmission is not affected, the transmission range is higher in comparison to the aforementioned implementation variant, because the influence of the transmission loss between the two road users T1, T2 is contained only simple and not square.

In known transmission properties of the transmission medium 80 can be inferred in one of the aforementioned implementation variants of the signal strength on geometric relationships between the road users, especially because the electro-acoustic transducers used in the sensors are usually characterized by a directional characteristic. Thus, under these conditions, only from the received signal strength of a transmitted signal 11 . 71 , which is recorded by a road user T1, T2 with only one receiving electro-acoustic transducer, the total attenuation of the transmitting and the receiving electro-acoustic transducer are already determined. Includes the receiver 30 . 50 At least two receiving electro-acoustic transducers (not shown separately) and the two electro-acoustic transducers are running time apart, the spatial orientation of the transmitting electro-acoustic transducer of the different strengths of the received signals in conjunction with the different maturities sending traffic participant T1, T2 to the receiving electro-acoustic transducer of the road user T2, T1 of which the directivity is known determined. If the position of the transmitting electro-acoustic transducer at the transmitting road user T1, T2 known, can be determined in this way alone by means of a message, the spatial relationship including the orientation of the electro-acoustic transducer to each other and thus the road users T1, T2 to each other ,

If the scene does not change or changes only negligibly slowly, subsequently exchanged acoustic information contains the spatial relationships of the sound medium 80 located road users T1, T2 equivalent as redundant information, otherwise as new information about the changing spatial conditions.

In a further preferred embodiment, by the transmission in the sound medium 80 received signals 31 an initialization message 11 and / or by the transmission in the sound medium 80 received signals 51 a reaction emission 71 evaluated on the basis of characteristic features such as signal strength.

Exceeds, for example, the signal strength of the received from the road user T2 acoustic signals 51 the initialization of the road user T1 or a sound source located in the acoustic environment a predetermined threshold, which is set, for example, depending on the signal strength of the noise, the road user T2 draws this acoustic signal 51 in a particularly preferred form by scanning as a discrete-time signal. After a fixed period of time TD, which may have different lengths TD1, TD2, the second road user T2 transmits at least one fixed time segment, for example the beginning of at least one of the previously received and recorded by the road user T2 acoustic initialization signal 51 , In particular, the to be sent

signal section 71 amplified, preferably in reverse order, which means that the last received signal portion is sent first. This is preferably done at a different playback speed, which means that the signal section to be transmitted 71 is sent on a different frequency. Thus, this in turn of the acoustic signals 11 the emissions of the first road user T1 are separated by means of filtering low effort.

In a very advantageous embodiment, the Reaktionsaussendungen 71 from the road user T2 and / or at least one other road user (not shown) on a unique relationship to the initialization of the road user T1. For example, it may be a signal excerpt of the emissions from the road user T1 in the reaction emissions 71 in time inverse order (colloquially "playing backwards") or in unchanged time order and optionally reproduced in the same playback speed or other playback speed and thus in a different frequency position than the frequency sent by the road user T1 frequency position. The storage of signal segments can preferably be realized by scanning. Furthermore, the reproduction in a changed frequency position can then preferably be realized by means of a modified playback speed of the sampled values. Alternatively, in the reaction emissions 71 used signal shape determined by an encoding, which can be realized for example by means of an allocation table or by an algebra.

According to the invention, by varying the sampling frequency during transmission in relation to the sampling frequency when receiving, the frequency position and the pulse duration of the reaction emissions 71 the at least one received initialization signal (initialization message) 51 responding road users, such as the road user T2, are varied. For example, twice as fast sending of the acoustic signals 71 the reaction emissions of the second road user T2 the sound medium 80 only half as long as needed the same signals 71 at the playback speed with which they were recorded. Are in the medium 80 In addition to the road users T1, T2 in particular also other road users (not shown), the present invention based on an evaluation of the characteristics of the received signals 51 . 31 in each case the emission of reaction emissions 71 or initiate further reaction emissions (not shown), then halves due to the respective use of the medium 80 the probability of collision of the reaction emissions in the medium 80 , The use of a double signal frequency leads to a smaller range of this reaction signal due to the frequency-dependent room attenuation 71 or a further reaction signal (not shown) and thereby also a reduction of the spatial collision probability of reaction emissions. In addition, thanks to the doubling of the signal frequency of the acoustic signals 71 the reaction emissions to the acoustic signals 11 the initialization transmissions separate them more easily by frequency filters. The same applies to reaction transmissions (not shown) from the road user T1 as a result of initialization transmissions (not shown) from the road user T2.

Thanks to the fixed delay time (delay) TD, it is only possible for such road users to experience collisions of reaction emissions which are at the same distance from the road users T1 initiating the acoustic exchange. If the road users at the same distance move with different relative speeds, the effect of collision is reduced thanks to the Doppler effect.

Thanks to the fixed delay time TD, the road user T1, who initiated the initialization transmission, can deduce the distance between the two road users T1, T2 at the moment of the signal exchange from the time between the time at which the initialization transmissions were generated and the time at which the associated reaction transmission is received ,

Thanks to the evaluation of acoustic signals on the basis of the simple characteristic feature "signal strength", the Doppler information contained in the signal about the relative movement of the road users (for example vehicles) T1, T2 relative to one another is preserved.

Thanks to the use of signal strength as a simple characteristic feature in the evaluation of received signals 51 . 31 Interoperability is easily possible. The method is easy to implement. The reacting road users T1, T2 and / or the responding other road users (not shown) need for the realization of the method according to the invention no knowledge about the internal structure of the sent Initialisierungsaussendung 11 , in particular not on the time course of the signal frequencies or on the time course of the signal amplitude. However, an easily realizable threshold value switch sets the time, after which an incoming signal is exceeded, once the threshold has been exceeded by the signal strength 51 . 31 is recorded. With easily realizable time measuring devices, the storage duration and the delay time TD can be determined. After the fixed delay time TD, the stored signal is sent out again.

An interoperability of different methods, which are realized for example by different manufacturers, is possible. For example, the method according to the invention works independently of the modulation type of the initialization signals 11 , For example, one system may use low-cost amplitude modulation, or even amplitude-biasing, while other systems may use frequency-shift keying or even m-frequency or frequency-modulated continuous-frequency signals, or noise-like signals or phase-shift keying, such as quadrature amplitude modulation. A road user, such as the road user T2, who is sending a reaction 71 (Replay) generated on any such modulated Initialisierungsaussendung needs no knowledge of the modulation used in each case. Thus, an upward compatibility between different systems is possible. For example, a system that itself only amplitude shift as a modulation type of an initialization transmission 11 also generate a replay to receive noise-like modulated signals.

In a preferred embodiment, the signal frequency changes continuously with time, at least in a period of the initialization transmission, that is to say that the initialization transmission is chirp-modulated during the said time segment.

Thanks to the use of signal strength as a simple characteristic feature in the evaluation of received signals 31 . 51 may in the method described here preferably also a reaction emission 71 be generated on the arrival of such acoustic signals, which were not explicitly generated as measurement signals for environmental monitoring and, inter alia, engine noise, footstep sound, squeaks, for example Bicycles or acoustic signals from traffic lights. This effect allows other road users, such as the road user T2, not only on the basis of such explicitly sent as measurement signals for monitoring the environment Initialisierungsaussendungen 11 and based on the resulting echoes of passive reflective objects to orient, but also based on reaction emissions of other road users, such as T1, and the resulting echoes of passive reflecting objects. In this way the used medium becomes 80 , in which the sound propagates, even with few emissions 11 . 71 Measured with a wealth of signals, thanks to the contained mostly redundant information a rapid reliable determination of position and movement in the medium 80 Even if only a few road users, such as the road user T2, by active emission of reaction emissions 71 involved. It is also those road users who do not actively send but evaluate only the incoming acoustic signals, such as the road user T2 possible, the position and the movement of others in the medium 80 located road users, such as the road user T1, and otherwise in the medium 80 to determine located objects.

Also, the use of a combination of several characteristic features (signal properties), such as the signal strength and / or the time course of the signal strength (for example in the form of the frequency of occupancy of the medium 80 ) and / or the time course of the signal frequency or the signal frequency mixture in the evaluation of the received signals 51 . 31 is possible. For example, reaction emissions 71 more often on such Initialisierungsaussendungen 11 to be generated. Such more frequently generated reaction emissions 71 may in particular be reproduced at a respective different playback speed and / or generated with a respective different delay time TD and / or have a respective different transmission duration TP2 and / or have a different reproduction order, if preferred in addition to, for example, a minimum signal strength special further signal characteristics such as have a special signal frequency characteristic.

The characteristic features of the reaction emissions realized in this way 71 thus have easy-to-understand properties. So the total runtime is between sending out the initialization message 11 and receiving the reaction message 71 Taking into account the known to all road users T1, T2 delay time TD a measure of the distance of the road users T1, T2. The frequency changes are a measure of the relative movement of the road users T1, T2 to each other in the consideration of all the road users T1, T2 known rules of the modified playback speeds and the change in the signal strength is in the consideration of the instantaneous propagation loss in the medium 80 a measure of the orientation of the road users (communication partners) T1, T2 to each other.

In order to avoid collisions of the reaction emissions with reflections of non-active, that is, of reflective objects, either a long delay time TD should be used so that all echoes from potentially distant objects are already closer to the receiver 30 are and in particular at least one waveform of the actively emitted acoustic signals 71 the reaction emissions, which differs significantly from the waveform of the echoes of passive reflecting objects. The acoustic signals 71 The response emissions may, for example, be distinguishable from the echoes of passive reflecting objects based on the time course of the signal frequency in frequency modulated waveforms and / or on the signal frequency, which may be generated in particular by means of a modified playback speed.

For a good signal separation between the acoustic signals 11 of initialization transmissions and the acoustic signals 71 Of reaction emissions through frequency filters already sufficient for some applications, a lower Frequenzverschiebung- or change the playback speed. Are in an area of the sound medium 80 For example, two vehicles T1, T2 with absolute speeds of 60 km / h, ie 17 m / s, the maximum relative speed of the two encountered vehicles T1, T2 34 m / s amount, which is a Doppler shift of about 10% of the signal frequency of acoustic signals 11 the initialization emissions at the reaction receiver T1 causes.

2 shows the position of the possible Doppler band DR of a reaction emission at the responding road user (reactor) T2 in comparison to the position of the Doppler band DI of the corresponding initialization transmission in the originally initializing road user T1 at a 1.5 times playback speed.

The ratio of playback speed to recording speed in the reactor T2 is referred to in this context as the relative playback speed RA.

It becomes clear that both bands DI, DR do not overlap, even with an extreme value analysis. It looks even better for the relationship between an initialization broadcast and an associated broadcast because both bands change in the same direction.

In traffic situations in which only a few acoustically active road users T1, T2 an area of the sound medium 80 However, it is also advisable to emit the acoustic signals of the reaction broadcasts with a lower playback speed, which corresponds to a shift towards lower signal frequencies. Due to the small number of road users T1, T2, the probability of collision of the reaction emissions is low despite the extended pulse duration compared to the initialization transmissions. Advantageously, the choice of the lower signal frequency can then be when higher ranges must be achieved, since the room attenuation increases with the signal frequency.

Alternatively, a change of the signal frequencies makes sense to avoid interferers. This applies both to the initialization transmissions of the initializing traffic participant T1 and to the reaction transmissions of the responding traffic participant T2.

The method is thus preferably carried out in such a way that the selection of the signal frequencies of the initialization transmissions and the relative playback speed RA during playback (replay) take place according to the situation, but in such a way that the respective traffic participant (communication partner) T1, T2 changes according to previously agreed rules can recognize from acoustic signals. For example, this is achieved by using only clearly distinguishable levels of in the reaction 71 contained references to the Initialisierungsaussendung 11 , in particular the relative playback speed, and / or the different delay time TD and / or the signal length are selected.

Taking into account the fact that a road user T1, T2 in the acoustic environment detection usually receives the active emissions of at least one other road user T2, T1 with at least two receiving systems, which are distributed spatially distributed to the road users T1, T2, so can on the basis of spatial differences the received emissions, in particular on the basis of the transit time differences and / or the signal strength and / or the signal changes during the transmission path, at least the spatial relationship between the emitting and the receiving road users T1, T2 are determined, a statement about the relative movement between the emitting and the receiving Road users T1, T2, on the traffic conditions between the sending and receiving road users T1, T2, in particular the position and / or the shape of the intervening other road users and / or stationary objects, such as trees, and / or on the road surface, be inferred.

In a preferred embodiment, at least one road user T2, in which a plurality of electro-acoustic transducers (not shown separately) are aligned with a region of the medium, does not send a reaction emission via each electro-acoustic transducer 71 sent. For example, after receiving an initialization message 11 a corresponding reaction emission 71 are emitted via the electro-acoustic transducer through which the acoustic signals 51 the initialization transmission with maximum signal strength were received, and simultaneously or with a time delay, that is, after a different delay time TD, at least one further corresponding reaction emission 71 are emitted via the electro-acoustic transducer through which the acoustic signals 51 received the initialization transmission with the lowest signal strength. Further combinations are possible.

In a further preferred embodiment, at least one road user takes part in the medium 80 Traffic participants T1, T2 alternately different of the aforementioned functions, that is, that this road user, for example, once as initiating road users (initiator) T1 of the acoustic exchange and other times as a responsive road user (reactor), such as the road user T2, the with reaction emissions 71 on receipt of the acoustic signals 51 an initialization message responds, behaves. In a preferred embodiment, an initiating road user (initiator) T1 confirms receipt of the acoustic signals 31 one of a reacting road user (reactor) T2 previously emitted reaction emission 71 likewise by emitting a further reaction emission (not shown). In this way, both the initiating road user T1 receives confirmation that the responding road user T2 the acoustic signals 51 has received its initialization, as well as the responding road user T2 receives an acknowledgment of the receipt of the acoustic signals 31 its reaction emission by the initiating road user T1. Such confirmed transmissions help to meet the increasing reliability requirements of environmental monitoring.

Both the reaction emissions 71 , as well as the Initialisierungsaussendungen 11 In addition to the information for implementing the method according to the invention (replay protocol), further information such as, for example, the vehicle dynamics state of the vehicle and / or the vehicle identification may also be included.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3024791 C2 [0006]
• DE 2335613 A1 [0007]
• DE 2335613 B2 [0007]

Claims (14)

Method for determining the relative distance and / or the relative movement between at least two road users (T1, T2), in particular between at least two vehicles, wherein the reception of acoustic signals ( 51 ), which consist of initialization transmissions in the form of acoustic signals ( 11 ) transmitted by a first road user (T1), by a second road user (T2), are emitted in the form of acoustic signals ( 71 ), which are received and evaluated by the first road user (T1), characterized in that the reaction emissions of the second road user (T2) after the expiration of at least one of the road users (T1, T2) known delay time (TD) are made, the is set so long that received from the first road user (T1) acoustic signals that come from passive reflections of the initialization of the first road user (T1) to environmental objects, no effect on one of the first road user (T1) made evaluation by means of at least one Receiver ( 30 ) received reaction ( 71 ) of the second road user (T2). A method according to claim 1, characterized in that on the basis of the first road user (T1) received acoustic signals ( 31 ) of the reaction emissions of the second road user (T2) reaction emissions of acoustic signals of the first road user (T1) after the expiration of at least one of the road users (T1, T2) known and such a long delay time are triggered that received from the second road user (T2) acoustic Signals originating from passive reflections of the acoustic signals of the reaction transmissions of the first road user (T1) to surrounding objects have no influence on one of the second road user (T2) for determining the relative distance and / or the relative movement between the two road users (T1, T2) carried out by the second road user (T1, T2) by means of at least one receiver ( 50 ) received acoustic signals of the reaction emissions of the first road user (T1). Method according to one of the preceding claims, characterized in that the signal duration (TP2) of the acoustic signals (TP2) 71 ) of the reaction emissions of at least one traffic participant (T2) is less than a predetermined fraction of the signal duration (TP1) of the acoustic signals of the initialization transmissions of the first traffic participant (T1) and / or at least one signal duration (TP2) and / or at least one frequency or at least one frequency response the acoustic signals ( 71 ) of the reaction emissions of at least one road user (T2) the road users (T1, T2) is known. Method according to one of the preceding claims, characterized in that in the acoustic signals ( 71 ) of the reaction emissions of at least one road user (T2) information concerning these reaction emissions, in particular information comprising the at least one delay time (TD) used for these reaction emissions and / or the signal duration (TP2) and / or the signal frequency or the signal frequency characteristic of the corresponding acoustic signals to be modulated. Method according to one of the preceding claims, characterized in that at least one evaluation of the acoustic signals carried out for determining the relative distance and / or the relative movement between the road users (T1, T2) ( 11 ) of the initialization transmissions of the first traffic participant and / or of the acoustic signals ( 71 ) of the reaction emissions of at least one road user (T2) at least one characteristic feature of the acoustic signals ( 11 ) of these initialization transmissions and / or the acoustic signals ( 71 ) of these Reaktionsaussendungen, in particular the signal strength and / or the time course of the signal strength and / or the signal frequency and / or the time course of the signal frequency or the signal frequency mixture of the corresponding acoustic signals is used. Method according to one of the preceding claims, characterized in that the signal strength and / or the waveform of the acoustic signals ( 71 ) of the reaction emissions of at least one road user (T2) has a clear relationship to the signal strength and / or to the signal curve of the acoustic signals ( 11 ) of the Initialisierungsaussendungen of the first road user (T1), which in particular have a time-varying frequency characteristic has. Contraption ( 100 ) for determining the relative distance and / or the relative movement between at least two road users (T1, T2), in particular between at least two vehicles, which is adapted to the initialization of audible signals generated by at least one road user (T1) of the two road users ( 11 ) by means of at least one recipient ( 50 ) and to recognize them by means of an evaluation as such and in response to the received acoustic signals ( 51 ) of the initialization transmissions of the at least one road user (T1) emitting emissions of acoustic signals ( 71 ), characterized in that the device ( 100 ) is adapted to the reaction emissions of acoustic signals ( 71 ) with at least one predetermined signal duration (TP2) after the expiration of at least one predetermined delay time known to the road users (TD). Contraption ( 100 ) according to claim 7, characterized in that the device ( 100 ) is configured to generate initialization transmissions of acoustic signals having at least one predetermined signal duration, which are recognizable as such at least by the further traffic participant (T1) by means of an evaluation, and those of the further traffic participant (T1) in response to that of the device ( 100 ) generated after the expiration of at least one predetermined and the road users known delay time (TD) generated by the reaction emissions of acoustic signals by means of at least one receiver ( 50 ) and recognize it as such on the basis of an evaluation. Contraption ( 100 ) according to one of claims 7 or 8, characterized in that the device ( 100 ) is adapted, in response to the received, generated by the at least one road user reaction emissions of acoustic signals further reaction emissions of acoustic signals with at least a predetermined signal duration after the expiration of at least one predetermined and the road users (T1, T2) known delay time (TD) to create. Contraption ( 100 ) according to any one of claims 7 to 9, characterized in that the device is adapted to emission of acoustic signals ( 71 ) with at least one signal duration (TP2) known to the road users (T1, T2) and / or with at least one frequency known to the road users (T1, T2) or with at least one frequency characteristic known to the road users (T1, T2). Contraption ( 100 ) according to one of claims 7 to 10, characterized in that the device ( 100 ) is adapted to react emissions of acoustic signals ( 71 ) with modulated information pertaining to these reaction emissions. Contraption ( 100 ) according to one of claims 7 to 11, characterized in that, the device ( 100 ) is adapted to receive the received acoustic signals ( 51 ) of the Initialisierungsaussendungen and / or the received acoustic signals of at least the other road user (T1) using at least one characteristic feature of these received acoustic signals to evaluate. Contraption ( 100 ) according to one of claims 7 to 12, characterized in that the device ( 100 ) is adapted to react emissions of acoustic signals ( 71 ) having a signal strength and / or a waveform that has a clear relationship with the signal strength and / or the waveform of the received ( 51 ) and in particular with a time-dependent frequency response generated acoustic signals ( 11 ) of the initialization transmissions of at least the further traffic participant (T1). Vehicle assistance system with a device ( 100 ) according to one of claims 7 to 13.

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