DE102019205534A1 - Method for operating an in particular at least partially automated vehicle - Google Patents

Abstract

A method for operating an in particular at least partially automated vehicle (100), comprising the steps of: emitting an acoustic test signal (S1); - receiving the acoustic test signal (S1); - determining a functional status of at least one microphone (121a ... 121n) Comparing the emitted acoustic test signal (S1) with the received acoustic test signal (S1), a correlation of the emitted acoustic test signal (S1) with the received acoustic test signal (S1) being carried out, with a time offset between the emitted acoustic test signal for the correlation (S1) and the received acoustic test signal (S1) is corrected.

Description

The present invention relates to a method and a device for operating an in particular at least partially automated vehicle. The invention also relates to a computer program. The invention also relates to a machine-readable storage medium.

State of the art

During the operation of a vehicle, a vehicle driver can perceive different ambient noises from the vehicle's surroundings. For driving safety, driving noises from other road users, their horn signals, warning signals or sound signals, such as e.g. Special signals from emergency vehicles and the like are important. The driver of the vehicle can easily perceive these with his hearing and often also classify them according to importance and possibly localize the noise or sound source approximately.

As a result, the vehicle driver can, for example, carry out a suitable driving maneuver. Driver assistance systems or systems that enable at least partially automated driving, on the other hand, are not easily able to perceive ambient noises from the vehicle's surroundings or to derive suitable driving maneuvers from them. Therefore, in particular for the operation of such a vehicle, there may be a desire for improved acoustic detection of a vehicle environment or a vehicle external environment.

US 2016/0127845 A1 discloses a method of detecting blockage for MEMS microphones. The blockage is determined by a processor in that an output signal from one or more microphones is evaluated and, if necessary, compared with one another. Furthermore, reference signals can also be generated by a tone generator.

US 9648433B 1 discloses a similar method for calibrating MEMS microphones.

Disclosure of the invention

It is an object of the present invention to provide an improved method for operating a vehicle.

• - Aussenden eines akustischen Testsignals;
• - Empfangen des akustischen Testsignals;
• - Bestimmen eines Funktionsstatus wenigstens eines Mikrofons durch Vergleichen des ausgesendeten akustischen Testsignals mit dem empfangenen akustischen Testsignal, wobei eine Korrelation des ausgesendeten akustischen Testsignals mit dem empfangenen akustischen Testsignal durchgeführt wird, wobei für die Korrelation ein zeitlicher Versatz zwischen dem ausgesendeten akustischen Testsignal und dem empfangenen akustischen Testsignal korrigiert wird.

According to a first aspect, the object is achieved with a method for operating an in particular at least partially automated vehicle, comprising the steps:

• - sending out an acoustic test signal;
• - receiving the acoustic test signal;
• - Determination of a functional status of at least one microphone by comparing the transmitted acoustic test signal with the received acoustic test signal, a correlation of the transmitted acoustic test signal with the received acoustic test signal being carried out, with a time offset between the transmitted acoustic test signal and the received acoustic test signal for the correlation Test signal is corrected.

In this way, information can advantageously be obtained as to whether the microphone has heard the acoustic test signal or not. The test signal can advantageously be a particularly quiet and therefore inconspicuous noise, as a result of which operation of the vehicle is not disrupted. This can take place particularly reliably, since the functional status of the microphone, which can be, for example, an error-free function, a partially disturbed function or an inoperability of the microphone, can be determined during operation of the vehicle. In this way, for example, impurities such as water, snow, ice, slush, etc., which interfere with the function, can be detected. If a malfunction of the microphone is detected, a warning or the like can be sent to an operator of the vehicle. It is also possible that if a malfunction of the microphone is detected for certain or all driving functions of the vehicle, a substitute measure is initiated that brings the vehicle into a safe state, for example.

According to a second aspect, the object is achieved with a control device which is set up to carry out the proposed method.

According to a third aspect, the object is achieved with a computer program comprising commands which, when the computer program is executed by a computer, cause the computer to carry out the proposed method.

According to a fourth aspect, the object is achieved with a machine-readable storage medium on which the computer program is stored.

The dependent claims relate to advantageous developments of the method.

An advantageous development of the method provides that the functional status of the at least one microphone is determined to be negative when the result of the correlation falls below a defined threshold value. Under a negative Functional status of the microphone can in particular be understood to be an at least partially disturbed function that (no longer) allows reliable acoustic detection of the vehicle exterior environment or audio detection, or a complete failure of the microphone.

Another advantageous development of the method provides that the acoustic test signal emitted is pink noise. This type of acoustic test signal is a band-limited, quasi-random signal, as a result of which the signal is advantageously barely audible.

Another advantageous development of the method is characterized in that the acoustic test signal is sent out permanently or at defined times when the vehicle is in operation. In this way, the method can be carried out at defined times.

Another advantageous development of the method provides that a reference signal from the vehicle is used to determine the time offset between the transmitted acoustic test signal and the received acoustic test signal. As a result, a time offset between the acoustic test signals is determined, so that the correlation of the transmitted acoustic test signal with the received acoustic test signal can be carried out even better.

The acoustic source for the reference signal can be passive and e.g. Driving noises of the vehicle, such as rolling noises, wind noises, or operating noises of a vehicle component, noises when opening or closing a vehicle door, noises when locking or unlocking a vehicle door or the like. The acoustic source for the reference signal can, however, also be actively controllable to generate a reference tone or a reference tone sequence. For example, a loudspeaker of the vehicle, e.g. the communication with the outside of the vehicle, in particular with passers-by, can be controlled to generate the reference signal.

Another advantageous development of the method is characterized in that the time offset between the transmitted acoustic test signal and the received acoustic test signal is determined at defined times during operation of the vehicle. Due to the fact that signal propagation times are dependent on temperature / air pressure, an improved elimination of the time offset is carried out and thereby a better correlation of the acoustic test signal with the received acoustic test signal is made possible.

A further advantageous development of the method provides that functional statuses are determined by a plurality of microphones, with a single microphone with a negatively determined functional status for the operation of the vehicle being weighted at least less. This advantageously increases the reliability of the acoustic detection device when the vehicle is in operation.

Another advantageous development of the method provides that the functional status is determined during a defined period of time. This advantageously takes account of the fact that a blockage of a microphone can, under certain circumstances, also be released or released by itself (e.g. by a cleaning process, etc.). For this reason, the determination of the correlation is carried out over a defined period of, for example, several seconds, as a result of which, in particular, permanent blockages of the microphone are detected.

Another advantageous development of the method provides that the emitted acoustic test signal is divided into individual frequency bands. A further improvement of the method is advantageously achieved in this way, since impairments of the microphones can thereby be determined in a defined frequency band. This is achieved by subjecting the complete test signal to the correlations in frequency bands.

Another advantageous development of the method provides that the emitted acoustic test signal has no direct current component. In this way, it is even easier to determine the correlation and thus to determine the functionality of the microphone easier.

Further measures improving the invention are illustrated in more detail below together with the description of preferred exemplary embodiments of the invention with reference to three figures.

Figure list

• 1 ein Übersichtsbild eines Fahrzeugs mit einer vorgeschlagenen Vorrichtung zum Betreiben des Fahrzeugs;
• 2 ein Blockschaltbild einer Vorrichtung zum Betreiben eines insbesondere automatisiert fahrenden Fahrzeugs; und
• 3 einen prinzipiellen Ablauf eines vorgeschlagenen Verfahrens zum Betreiben eines insbesondere automatisiert fahrenden Fahrzeugs.

In the figures shows:

• 1 an overview image of a vehicle with a proposed device for operating the vehicle;
• 2 a block diagram of a device for operating a vehicle that is particularly automated; and
• 3 a basic sequence of a proposed method for operating a vehicle that drives in particular in an automated manner.

Embodiments of the invention

1 shows a vehicle in a basic plan view 100 with a device 200 to operate the vehicle 100 . The vehicle 100 is designed, for example, as an at least partially automated vehicle which has at least one, preferably as in 1 shown, multiple microphones 121a ... 121n has, which is essential for a safety-relevant functionality of the vehicle 100 could be. For example, the microphones 121a ... 121n for this purpose, beeps from emergency vehicles can capture the vehicle 100 as a consequence, for example, can perform evasive and / or braking maneuvers.

The microphones 121a ... 121n are on the outside of the vehicle 100 , especially in its wet area, arranged. The location of the microphones 121a ... 121n requires that the microphones can be affected by external mechanical influences. For example, dust, dirt, ice, water, etc. can affect the membrane of a microphone 121a ... 121n restrict in his movement. Also by cleaning measures or on the microphones 121a ... 121n hitting objects can damage the membranes.

2 shows a block diagram of a proposed device 200 for operating a particularly partially automated vehicle 100 . The device 200 assigns a speaker 110 for sending out an acoustic test signal S1 on. One recognizes an acoustic detection device 120 for the detection of noises or tones in the vehicle environment, for example a sound source arranged in a vehicle external environment 300 . At the sound source 300 it can be, for example, another road user (eg an emergency vehicle) or the like. The acoustic detection device 120 has one, preferably several microphones 121a ... 121n on. The microphones 121a ... 121n are in particular in one of the vehicle 100 oriented towards the direction of the future. Preferably the microphones are 121a ... 121n set up to record acoustic signals in an exemplary frequency range from approx. 20 Hz to approx. 20,000 Hz, which corresponds approximately to the average human hearing range.

One can also see one with the detection device 120 functionally connected evaluation device 130 , preferably in the form of an electronic control unit for evaluating the received acoustic test signal by means of the proposed method. On the evaluation device 130 the method embodied as a software program can be executed, but alternatively discrete components (not shown) can also be provided for executing the method. The acoustic test signal S1 is prepared via an air path P in the vicinity of the vehicle 100 and arrives at the acoustic detection device 120 .

That from the detection device 120 recorded acoustic test signal S1 is sent to the evaluation device 130 transmitted, whereby from the evaluation device 130 a correlation between the transmitted test signal S1 and the received test signal S2 is carried out. The evaluation device transmits the result of the correlation 130 an evaluation signal AS to one or more higher-level systems of the vehicle 100 , for example to a driver assistance system, a siren detection (not shown), or the like of the vehicle 100 .

Before the correlation, a signal transit time of the acoustic test signal is also determined S1 carried out between transmission and reception, so that the transmitted and received acoustic test signal S1 are correlated with one another as simultaneously as possible, whereby meaningful information about a correlation between the test signals is provided. Because the signal delay of the acoustic test signal S1 depends on the temperature or the air pressure, it makes sense to measure the signal transit time when the vehicle is in operation 100 permanent, but it can also only be done at defined times.

For the above-mentioned determination of the signal transit time, for example, this can be done on the basis of legal requirements when starting an electric vehicle 100 Generated noise that mimics the noise of a classic vehicle as an acoustic reference signal R1 be used. A tone generator or loudspeaker can be used for this purpose. This defined reference signal R1 can thus lead to an initialization or calibration of the device 200 be used. Because the said reference signal R1 However, if the transmission is not permanent, but for example only below a vehicle speed of approx. 20 km / h, it cannot be used for a continuous blockage assessment of the detection device 120 be used. Instead, the initial reference signal R1 used in the present invention to determine the signal propagation time or transmission delay between the loudspeaker 110 and the individual microphones 121a ... 121n the detection device 120 to eat.

The acoustic detection device 120 is functional (preferably via a data interface) with the evaluation device 130 connected so that's from the microphones 121a ... 121n recorded acoustic test signal S1 to the evaluation device 130 can be supplied or evaluated by this.

2 thus shows an apparatus 200 for operating an in particular at least partially automated vehicle 100 , having a loudspeaker 110 for sending out an acoustic test signal S1 , a receiving device 120 with at least one microphone 121a ... 121n to receive the acoustic test signal S1 and an evaluation device 130 for determining a functional status of the at least one microphone 121a ... 121n by comparing the emitted acoustic test signal S1 with the received acoustic test signal S1 , wherein a correlation of the transmitted acoustic test signal S1 with the received acoustic test signal S1 can be carried out, with a time offset between the emitted acoustic test signal for the correlation S1 and the received acoustic test signal S1 is corrected.

A method is proposed by which the above-mentioned contamination, damage or other impairment of the microphones 121a ... 121n ("Blockages" or "blockages") can be recognized. The functionality of the microphone can be determined by determining the signal transit time in advance or at the same time 121a ... 121n can be checked easily and very efficiently.

The initial phase of vehicle operation, during which a loud audible tone has to be played, differs from the operating phase of the vehicle, during which no audible tone has to be played. In the operating phase, unpredictable background noises, such as airflow, sirens, rolling noises, etc., must also be expected to a greater extent.

It is proposed as an acoustic test signal S1 Generate a broadband, quiet and, for example, quasi-random signal (such as pink noise) during the operating phase and via the loudspeaker 110 to reproduce. Advantageously, this signal is normally inaudible for people, since it is below the current perception threshold.

Nonetheless, the microphone under test can 121a ... 121n record it together with numerous background noises. Since the quasi-random test signal S1 and the background noises are not statistically correlated, but it is known which quasi-random signal with which delay at the microphones 121a ... 121n should be heard can be with a simple correlation between the time-delayed transmitted test signal S1 and the received test signal S1 be checked whether the microphones 121a ... 121n the quiet acoustic test signal S1 Listen. The mentioned correlation is determined by means of the evaluation device 130 carried out, which is preferably implemented in a control unit as a computer program.

• - Es wird ein Zeitraum verlängert, über den das gesendete akustische Testsignal S1 und das empfangene akustische Testsignal S1 miteinander verglichen werden
• - Es wird zum Zwecke einer besseren Erfassbarkeit die Lautstärke des quasizufälligen akustischen Testsignals S1 definiert erhöht

If, for example, no significant correlation is determined, this can also be due to the fact that the background noises mentioned are too loud and the reproduced acoustic test signal S1 cover completely. In this case, a better recognition can be achieved algorithmically, e.g. as follows:

• - A period of time is extended over which the transmitted acoustic test signal S1 and the received acoustic test signal S1 be compared with each other
• - For the purpose of better perceptibility, the volume of the quasi-random acoustic test signal is used S1 defined increased

Additionally it can be disruptive to the transmission functions of the speaker 110 and the microphones 121a ... 121n are not necessarily linear in the audible range. Then the correlation delivers poorer values for this reason alone.

When the acoustic test signal S1 is subdivided into individual frequency bands in advance, this effect can advantageously be reduced. In this case, instead of a representation over the entire audible frequency range, several representations over partial ranges are used, for which the described method is used individually. The blocking results of the individual methods can then be combined with one another for the purpose of an overall assessment.

Furthermore, it can be calculated mathematically whether the acoustic test signal sent S1 and the received test signal S1 have a direct current component. If this is the case, it indicates that, for example, there is an electrical short circuit and thus the microphone 121a ... 121n is likely blocked.

On the other hand, it is the electrical direct current component of the emitted acoustic test signal S1 close to zero, the calculation of the correlation is also simplified: it eliminates the need to determine a mean value and the current correlation of the transmitted test signal can be continuously calculated with a few arithmetic operations S1 with the received test signal S1 be calculated.

The initial phase can also be skipped if pink noise is used to determine the temporal transmission delay. An advantageous development of the method consists in the fact that the volume of the pink noise is continuously adapted in such a way that the determined correlation has a minimal but positive one Owns value. If the ambient noise becomes louder, the correlation typically drops unless the volume of the pink noise is also increased.

When determining the delay between the speaker 110 and the microphone 121a ... 121n the correlation can be calculated in the frequency domain.

If, for example, the initial delay deviates from stored values, this can also indicate that the acoustic detection device 120 is disturbed.

While the vehicle is in motion 100 Care should be taken to reduce the delays between the speakers 110 and the microphone 121a ... 121n be adapted over time, as the acoustic transmission through the air due to the temperature and the relative speed of the air relative to the vehicle 100 can be at different speeds. In order to achieve this, a further correlation with a reference signal additionally shifted in time by a small amount can also be carried out at regular intervals, for example R1 and the result can be used to adapt the signal propagation time in the direction of maximum correlation.

As in the block diagram of 2 is shown, detects at least one of the microphones 121a ... 121n the surroundings of the vehicle 100 acoustically, which here corresponds, for example, to recording the noises, tones or the like. These are used as audio signals by the evaluation device 130 fed. Either continuously or triggered by one or more definable diagnostic start conditions, for example when the vehicle is ready to drive 100 , i.e. still at a standstill before starting to drive, by actuating a door contact switch or the like, the evaluation device checks 130 the functional status of the microphone 121a ... 121n by sending the test signal S1 with the received test signal S1 is compared or correlated.

If there is a discrepancy between the acoustic test signal sent S1 and the received acoustic test signal S1 is detected, the microphone checked can 121a ... 121n marked accordingly. Depending on the extent of the deviation, the functional status can be assumed to be disturbed, complete failure, etc.

For this purpose, for example, a threshold value can be defined that can be parameterized up to which the deviation is still permissible, the functional status of the microphone when the threshold value is reached and / or exceeded 121a ... 121n is determined to be negative. This can cause the affected microphone 121a ... 121n weighted less in the acoustic environment assessment or possibly completely disregarded.

When a blockage or degradation of the acoustic detection device is detected 120 In a first measure, a higher-ranking vehicle system can be informed of this fact, which then only works partially or not at all. In a second measure it can be provided that the vehicle 100 put in a safe state, for example, is steered to a roadside and / or stopped.

3 shows a basic sequence of a method for operating an in particular at least partially automated vehicle 100 .

In one step 400 an acoustic test signal is sent out S1 carried out.

In one step 410 the acoustic test signal is received S1 .

In one step 420 a functional status of the at least one microphone is determined 121a ... 121n by comparing the emitted acoustic test signal S1 with the received acoustic test signal S1 , wherein a correlation of the transmitted acoustic test signal S1 with the received acoustic test signal S1 is carried out, with a time offset between the emitted acoustic test signal for the correlation S1 and the received acoustic test signal S1 is corrected.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• US 2016/0127845 A1 [0004]
• US 9648433 B [0005]

Claims (13)

Method for operating an in particular at least partially automated vehicle (100), comprising the steps: - Sending an acoustic test signal (S1); - Receiving the acoustic test signal (S1); - Determination of a functional status of at least one microphone (121a ... 121n) by comparing the transmitted acoustic test signal (S1) with the received acoustic test signal (S1), a correlation of the transmitted acoustic test signal (S1) with the received acoustic test signal (S1) is carried out, a time offset between the transmitted acoustic test signal (S1) and the received acoustic test signal (S1) being corrected for the correlation. Procedure according to Claim 1 , the functional status of the at least one microphone (121) being determined as negative if the result of the correlation falls below a defined threshold value. Procedure according to Claim 1 or 2 , the emitted acoustic test signal (S1) being pink noise. Method according to one of the preceding claims, wherein the acoustic test signal (S1) is transmitted permanently or at defined times when the vehicle (100) is in operation. Method according to one of the preceding claims, wherein a reference noise of the vehicle is used to determine the time offset between the transmitted acoustic test signal (S1) and the received acoustic test signal (S1). Method according to one of the preceding claims, wherein the time offset between the transmitted acoustic test signal (S1) and the received acoustic test signal (S1) is determined at defined times during operation of the vehicle (100). Method according to one of the preceding claims, wherein the functional status of a plurality of microphones (121a ... 121n) is determined, with a single microphone (121a ... 121n) having a negatively determined functional status for the operation of the vehicle (100) being weighted at least less. Method according to one of the preceding claims, the determination of the functional status is carried out during a defined period of time. Method according to one of the preceding claims, wherein the emitted acoustic test signal (S1) is divided into individual frequency bands. Method according to one of the preceding claims, wherein the emitted acoustic test signal (S1) has no direct current component. Control device (130), which is set up, a method according to one of the Claims 1 to 10 execute. Computer program comprising instructions which cause a computer to execute the computer program, a method according to one of the Claims 1 to 10 execute. Machine-readable storage medium on which the computer program is based Claim 12 is stored.

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