Adaptive Acoustic Vehicle Warning System

Abstract

The present invention relates to a pedestrian warning device for an electrically operable motor vehicle, comprising a warning sound generator and a warning sound controller configured to control the warning sound generator to generate a warning sound audible to people in the vicinity of the motor vehicle when reversing and / or driving forward slowly, the warning sound controller being configured to optimise the warning sound. Furthermore, the present invention relates to a method for operating the pedestrian warning device.

Description

[Technical field]

[0001] The present invention relates to a pedestrian warning device for an electrically operable motor vehicle and to a method for operating a pedestrian warning device for an electrically operable motor vehicle. [Background technology]

[0002] Since being laid down by law, passenger cars capable of purely electric power generation - BEVs, PHEVs and FCEVs - must have an acoustic warning device that cannot be switched off, which warns other road users, in particular pedestrians and cyclists, when the vehicle is travelling at low speeds.

[0003] The conditions for the warning are laid down in the European Union by Regulation (EU) No 540 / 2014 of the European Parliament and of the Council of 16 April 2014 on sound levels for motor vehicles (…), in particular in Chapter 2 "Acoustic Vehicle Alerting Systems (AVAS)" in conjunction with Annex VIII. The provisions contained therein on the warning sound allow for different sound productions, not only in terms of volume but also in terms of the frequency components used. The warning works more or less well in different vehicles, depending on the acoustic expression of the basic warning sound.

[0004] If environmental noise from other road users or, for example, a nearby construction site, exceeds a certain level, it could in theory be missed even by xEVs (BEV, PHEV, FCEV) that are legally required to provide an audible warning. Summary of the Invention [Problem to be solved by the invention]

[0005] Against this background, the object of the present invention is to improve the warning given to people in the vicinity of slowly moving electric vehicles. [Means for solving the problem]

[0006] Each independent claim defines by its features the object for which the problem is solved. The dependent claims relate to advantageous developments of the invention.

[0007] According to one aspect, a pedestrian warning device is disclosed for a motor vehicle which can be driven purely electrically, either temporarily or exclusively, i.e. in particular a battery electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV) or a fuel cell electric vehicle (FCEV).

[0008] The pedestrian warning device comprises a warning sound generator, which may for example be formed as a speaker, and a warning sound controller, which may for example be formed as a software component of a drive control or other control device typically installed in modern motor vehicles, and which is adapted to control the warning sound generator to generate a warning sound audible to people in the vicinity of the motor vehicle, in particular as long as at least one warning condition is fulfilled.

[0009] In particular, the warning conditions to be applied where necessary are prescribed by law and / or standards, for example in the European Union by Regulation (EU) No. 540 / 2014 of the European Parliament and of the Council of 16 April 2014 on noise levels of motor vehicles (...), in particular in Chapter 2 "Regulation on Acoustic Vehicle Alerting Systems (AVAS)" in conjunction with Annex VIII. Many other countries have their own similar legislation on this matter or have adopted European regulations or those similar in content to those of the USA, China or Japan.

[0010] The pedestrian warning device is configured to determine an environmental sound background of the vehicle and to determine and in particular adapt a warning sound depending on the environmental sound background, where "adapting the warning sound" is to be understood in particular as an adaptation of at least one characteristic of at least one warning sound variable, for example on the basis of a standard warning sound, and where "depending on the environmental sound background" is to be understood in particular as a determination / adaptation of the warning sound depending on at least one characteristic of the environmental sound variable of the environmental sound background.

[0011] This ensures that the warning sound can be heard reliably by people in the vicinity of the vehicle, even when there is a noisy and / or high-pitched environmental sound background.

[0012] According to yet another aspect, a method for activating a pedestrian warning device in an electrically drivable motor vehicle is disclosed, comprising at least the following method steps: (A) Identify the ambient sound background of a car; (B) determining and optimizing the warning sound according to the determined environmental sound background; (C) Emitting a determined and specifically adapted warning sound.

[0013] The invention is based on the idea that, inter alia, when environmental noise from other road users or, for example, a nearby construction site, exceeds a certain level, even xEVs (BEV, PHEV, FCEV) that legally provide an acoustic warning may be much more easily missed than internal combustion engines.

[0014] This is because the xEV warning sound has a fairly constant volume, whereas all internal combustion engines emit a sound that has a rhythmic repetition of louder and quieter moments, the louder moments of an internal combustion engine being (in some cases much) louder than the normal (legal) constant level xEV warning sound, making them easier to hear.

[0015] Furthermore, in many vehicles, the (legal) warning sounds are less irritating than the sounds of an internal combustion engine due to the relatively low amount of high frequency sounds, and therefore easier to miss in some circumstances - in quiet environments this is not usually the case, so there is no problem.

[0016] The invention is based on the idea, inter alia, of increasing the level of the xEV warning sound and / or making the sound quality of the warning sound more exciting and / or making it more noticeable, depending on the loudness and / or frequency distribution of the environmental sounds.

[0017] For this purpose, a sensor is required that can detect the environmental sound at least roughly, and the environmental sound can be used as a guide quantity for optimizing the sound synthesis of the warning sound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] According to one embodiment, a speakerphone device and / or a microphone for the voice input can be used to reduce costs and still be accurate enough if the sound generated by the vehicle itself (usually a radio / media player) is subtracted from the microphone output signal to estimate the time-averaged ambient sound reaching the vehicle from outside. In such an approach, according to one embodiment, the opening of windows and sunroofs can also be taken into account, and sound-proof glass can be taken into account as a correction factor if necessary. However, according to a preferred embodiment, in most applications / vehicle projects, the simple and therefore cheap microphones will still remain in the exterior area.

[0019] According to one embodiment, the driver may be offered a temporary manual switch to a more audible ambient sound ("horn-soft"), which may allow the driver in individual circumstances to target a warning to specific road users without startling them.

[0020] According to one embodiment, the pedestrian warning device is adapted to determine the environmental sound background based on characteristics of at least one environmental sound variable, such as the loudness and / or frequency distribution of the environmental sound background, thereby defining the nature of the sound signal that the warning sound generator must audibly overcome in order to be audible.

[0021] According to one embodiment, the warning sound controller is adapted to determine and in particular optimise at least one warning sound variable, such as for example the loudness and / or frequency or frequency distribution of the warning sound depending on the environmental sound background, so that the warning sound can be determined / optimised in such a way that it does not really go unheard in a background of various noises, nor does it possibly startle because it is inappropriately loud / high-pitched.

[0022] According to one embodiment, the optimized warning sound is at least one of: (a) louder than a non-optimized (standard) warning sound, in particular in its entire frequency spectrum or at least in part thereof, and / or (b) has a wider frequency spectrum than a non-optimized (standard) warning sound, in particular so that the optimized warning sound contains more high frequency components and / or has a more stimulating effect, thereby making it possible to more reliably warn people in the vicinity of the vehicle.

[0023] According to an embodiment, the pedestrian warning device can also generate a time-variable sound, in particular with its loudness and / or frequency content, by means of the warning sound controller, which at least temporarily overpowers random or substantially constant ambient sounds and thus draws attention to the warning vehicle. In particular, the warning sound then automatically alternates, in particular once or multiple times per second, between a normal emission and a more attention-grabbing emission due to its volume and / or frequency distribution, in order to better draw the attention of pedestrians to the movement of the vehicle. Such an embodiment can in particular be compared to the tail buzzer of a construction vehicle, and can be likened to a kind of "tail buzzer light", since the generated sound attracts attention by virtue of the repeated and time-varying warning sound, without the startling effect of a beep sound.

[0024] According to one embodiment, the pedestrian warning device comprises an environmental sound sensor configured to determine an environmental sound background, which allows determining (here, i.e. detected by a sensor) an actual environmental sound background and not just one based on a model.

[0025] According to one embodiment, the ambient sound sensor comprises an external microphone located outside the vehicle cabin, thus allowing for acoustically high quality detection of the ambient sound background using inexpensive hardware.

[0026] According to one embodiment, the ambient sound sensor comprises at least one internal microphone arranged in the vehicle cabin, in particular an internal microphone of a speakerphone device and / or a voice input device, in this way the ambient sound sensor can be implemented without additional hardware in most modern vehicles, i.e. with the internal microphone that is available anyway.

[0027] According to one embodiment, the warning sound controller is configured to take into account, in particular as correction factors, the opening of at least one window and / or sunroof and / or trunk and, if necessary, sound insulating glass, in order to determine the ambient sound background, so that the internal microphone can be used to detect sufficiently realistic values ​​of the ambient sound background in the vehicle cabin, regardless of the driving state.

[0028] According to one embodiment, the warning sound controller is configured to not take into account the vehicle's own sound for determining the environmental sound background, and in particular to subtract it from the total detected background noise, thus ensuring a proper determination of the environmental sound background.

[0029] According to one embodiment, the warning sound controller is configured to estimate the time average of the ambient sounds reaching the vehicle from outside or inside the vehicle in order to determine the ambient sound background, thereby ensuring a narrower determination of the ambient sound "background" without being overly influenced by loud and / or high-pitched individual noises.

[0030] According to one embodiment, the pedestrian warning device comprises a trigger unit configured to emit a tailored warning sound upon and / or during actuation by the vehicle driver. Such a "soft-horn" allows a user-activatable warning signal to be emitted audibly to an intended recipient without the startling potential of a standard horn.

[0031] According to one embodiment of the method, the optimized warning sound is emitted only upon and / or during operation by the vehicle driver.

[0032] According to an alternative embodiment of the method, the optimized warning sound is emitted only when and / or while at least one warning condition exists, which may be, for example, the current or expected future presence of a pedestrian, bicycle, motorbike or the like within the area of ​​the planned vehicle movement trajectory.

[0033] In order to detect a current warning condition, a camera system, which is anyway present in the vehicle and detects the surroundings, in particular has the ability to identify movement and / or obstacles and / or people.

Claims

Claim 1 A pedestrian warning device for an electrically drivable motor vehicle, a warning sound generator, a warning sound controller configured to control the warning sound generator to generate a warning sound audible to people around the motor vehicle when reversing and / or when moving forward slowly, in the pedestrian warning device comprising, the warning sound controller is configured to determine the environmental sound background of the motor vehicle and determine the warning sound according to the environmental sound background, and in particular, to optimize it, characterized in that the pedestrian warning device. Claim 2 The pedestrian warning device according to claim 1, wherein the environmental sound background is configured to be determined based on at least one environmental sound variable characteristic such as the loudness and / or frequency distribution of the environmental sound background. Claim 3 In the pedestrian warning device according to claim 1 or 2, the warning sound controller is configured to determine at least one warning sound variable such as the loudness and / or frequency or frequency distribution of the warning sound according to the environmental sound background, and in particular to optimize it, characterized in that the pedestrian warning device. Claim 4 In the pedestrian warning device according to claim 1 or 2, the optimized warning sound is, in particular, at least one of being louder in volume than the non-optimized (standard) warning sound in the whole or at least a part of its frequency spectrum or having a wider frequency spectrum than the non-optimized (standard) warning sound, characterized in that the pedestrian warning device. Claim 5 In the pedestrian warning device according to claim 1 or 2, the optimized warning sound is, in particular, temporally variable in terms of its loudness and / or frequency components, and in particular, automatically alternates between a normal emission mode and an emission mode that attracts more attention by volume and / or frequency distribution, characterized in that the pedestrian warning device. Claim 6 In the pedestrian warning device according to claim 1 or 2, comprising an environmental sound sensor configured to determine the environmental sound background, characterized in that the pedestrian warning device. Claim 7 In the pedestrian warning device according to claim 6, the environmental sound sensor comprises an external microphone disposed outside the vehicle cabin, characterized in that the pedestrian warning device. Claim 8 In the pedestrian warning device according to claim 6, the environmental sound sensor is characterized in that it comprises at least one internal microphone arranged in the vehicle cabin, in particular the internal microphone of a speakerphone device and / or a voice input device, in the pedestrian warning device.

9. In the pedestrian warning device according to claim 8, the warning sound controller is configured to consider, in particular as a correction factor, the degree of opening of at least one window and / or sunroof and / or trunk lid in order to determine the environmental sound background, in the pedestrian warning device.

10. In the pedestrian warning device according to claim 1 or 2, the warning sound controller is configured not to consider the sound of the motor vehicle itself in order to determine the environmental sound background, and in particular to subtract it from all detected background noise, in the pedestrian warning device.

11. In the pedestrian warning device according to claim 1 or 2, the warning sound controller is configured to estimate the time average of the environmental sound reaching the motor vehicle from the outside or inside the motor vehicle in order to determine the environmental sound background, in the pedestrian warning device.

12. In the pedestrian warning device according to claim 1 or 2, a trigger unit configured to emit the optimized warning sound during and / or when operated by a vehicle driver, in the pedestrian warning device.

13. A method for operating a pedestrian warning device in an electrically drivable motor vehicle, in particular the pedestrian warning device can have the configuration according to claim 1 or 2, - determining the environmental sound background of the motor vehicle, - determining, in particular optimizing, a warning sound according to the determined environmental sound background, - emitting the determined and in particular optimized warning sound characterized by the steps of.

14. In the method according to claim 13, the optimized warning sound is emitted only during and / or when operated by a vehicle driver, in the method.

15. In the method according to claim 13, the optimized warning sound is emitted only when and / or while a warning situation exists, in the method.