Open vehicle

Abstract

The invention relates to an open vehicle (1) with at least one surroundings sensor (2) and an evaluation unit (3), the evaluation unit (3) being designed to cause, depending on at least one signal of the surroundings sensor, a sound output device (4) to output a sound (5) to warn the driver (6) of the vehicle (1), wherein the at least one sound (5) has at least one frequency component in a frequency range from 900 to 20000, in particular 1000 to 10000, hertz.

Description

[0001] Open vehicle

[0002] The invention relates to an open vehicle with at least one environmental sensor and an evaluation unit, wherein the evaluation unit is designed to cause a sound emitting device to emit at least one sound to warn the driver of the vehicle, depending on at least one signal from the at least one environmental sensor. The invention also relates to a computer program product.

[0003] The use of sounds to warn a vehicle driver is common in many areas—on the road, rail, sea, or air. When a dangerous situation arises, the driver (or captain) is usually warned with a sound (acoustic signal)—often in conjunction with a visual signal. This usually indicates a mechanical or electronic malfunction in the vehicle or its engine.

[0004] A malfunction of this type typically persists for an extended period of time. When a warning light appears on the dashboard, the driver may not notice the malfunction for a few seconds or even a few minutes.

[0005] In recent years there have been many developments in driving assistants where environmental sensors detect the surroundings and assess whether a dangerous situation exists. Based on this, warnings or interventions in the vehicle or engine control can be issued to avoid accidents. Due to advances in technology, there are now also a variety of sensors that can be adapted to the space resources of motorcycles and support the development of driving assistants. The document DE 10 2019 215 508 A1 discloses a warning system for motorcycles. An environmental sensor determines the presence and location of other road users or other objects, in particular by determining an angle. If the angle of the front wheel exceeds a predefined angle, a warning is issued to avoid a collision with a detected object. The warning can be given acoustically, among other things.

[0006] Document DE 10 2018 126 916 A1 discloses a vehicle-to-vehicle communication system for motorcycles. Braking by a motorcycle traveling ahead can be signaled to the rider of a following motorcycle by means of a visual or acoustic signal emitted by an output device of the following motorcycle.

[0007] When using these systems, a quick warning to the user is essential, unlike the vehicle or engine malfunctions mentioned above. In such dangerous situations, a driver has very little time to react. It is therefore necessary to warn a driver as quickly as possible about a potential or already occurring hazard.

[0008] Acoustic signals (or sounds) are more suitable for this purpose than visual signals, as the driver perceives them immediately without having to look at a warning light. Acoustic signals are already widely used in enclosed vehicles.

[0009] However, when used on open vehicles, particularly motor-powered vehicles such as motorcycles, quads, buggies or convertibles, it cannot always be guaranteed that an audible signal will be heard or perceived due to the loud noise generated by the wind when driving at high speed. Sounds emitted by sound emitting devices such as loudspeakers mounted on the vehicle itself are difficult to hear due to the wind and the wearing of a helmet. An audible signal coming from a loudspeaker would have to be very loud and could therefore unintentionally distract or even frighten other road users, as well as the driver themselves.

[0010] It's common practice to position sound emitters inside the helmet so that the sound is generated close to the rider's ear. However, wind noise is still present inside the helmet. Sounds from sound emitters inside the helmet are often difficult to hear, especially when riding at high speed.

[0011] The object of the invention is to solve the problems mentioned. In particular, the object of the invention is to enable a warning to a driver of an open-top vehicle by means of at least one sound, wherein the warning triggers a reliable, rapid, and targeted reaction from the driver of an open-top vehicle.

[0012] The problem is solved by the independent claims 1, 6, 22 or 24.

[0013] According to the invention, the at least one sound has at least one frequency component in a frequency range from 900 to 20,000 Hertz. Preferably, all or a majority of the frequency components of the at least one sound are arranged in the frequency range.

[0014] "Frequency components" of the at least one sound are frequency components that are strong enough to be heard. A sound with frequency components in this frequency range results in a reliable reaction from the driver of the open vehicle, since such a sound is easily heard by drivers.

[0015] This is because the volume of the wind decreases with increasing frequency, from about 60 to 90 Hertz, which means that a sound with frequency components in the described frequency range can be more easily distinguished from the wind noise.

[0016] At least one sound is deep enough (frequency less than or equal to 20000 Hertz) to be heard by most (human) drivers.

[0017] In particular, the frequency range extends from 1000 to 10,000 Hertz. Sounds with frequency components in this range are more pleasant to listen to.

[0018] On the one hand, a sound is defined as a musical sound with a pitch, which in particular has essentially harmonic overtones. Furthermore, a sound within the meaning of the application can also be a combination of several individual sounds with different pitches. On the other hand, a sound can be a noise, which in particular has no harmonic overtones, or can have noise components.

[0019] The sound can be transmitted to the driver via airborne sound or structure-borne sound.

[0020] The at least one sound has a sound pressure level (SPL), wherein the sound pressure level, preferably in third-octave bands, is preferably in a range from 50 to 110 decibels. A sound in this sound pressure level frequency range results in a more reliable reaction from the driver of the open vehicle, since such a sound is typically loud enough (sound pressure level greater than or equal to 50 dB) to be distinguished from the wind noise.

[0021] The volume of wind noise decreases with increasing frequency. Therefore, high-pitched and loud sounds are preferable to wind noise in terms of audibility.

[0022] In addition, at least one sound is quiet enough (preferably a sound pressure level in third-octave bands less than or equal to 110 dB) not to damage the driver's hearing. The frequency-dependent hearing loss limit is therefore not exceeded.

[0023] At least one sound can therefore be reliably perceived at high speeds of up to 120 kilometers per hour by drivers with or without earplugs and without causing any hearing damage.

[0024] In other words, at least one, preferably all or a large part of the frequency component (s) and the sound pressure level are arranged within an imaginary range in a sound pressure level-frequency coordinate system, wherein the imaginary range is a rectangle with the corner points 110 decibels and 900 Hertz, 110 decibels and 20000 Hertz, 50 decibels and 20000 Hertz and 50 decibels and 900 Hertz.

[0025] To make the perception even more reliable, frequency components at lower sound pressure levels are preferably arranged in a smaller frequency range. In a particularly preferred embodiment, it is provided that at least one, preferably all or a large part of the frequency component (s) and the sound pressure level of the at least one sound are arranged within an imaginary range in a sound pressure level-frequency coordinate system, wherein the imaginary range is a triangle with

[0026] - a first corner point at 90 decibels and 900 hertz, and

[0027] - a second corner point at 90 decibels and 20000 Hertz, and

[0028] - a third corner point at 50 decibels and 5000 hertz.

[0029] The corner points 9, 10 and 11 can vary in frequency from plus to minus 100Hz depending on the driving speed, and the sound pressure level can also vary from plus to minus 100Hz depending on the driving speed.

[0030] Alternatives for the first corner point would be 80 decibels and 800

[0031] Hertz or at 100 decibels and 800 Hertz .

[0032] Alternatives for the second corner point would be 80 decibels and 19000 Hertz or 100 decibels and 21000 Hertz.

[0033] Alternatives for the third corner point would be 60 decibels and 5000 Hertz or 40 decibels and 5000 Hertz.

[0034] The sound pressure level of a frequency component can be determined by recording the signal, for example, with a sound pressure level meter, digitizing the signal, and mathematically applying a Fast Fourier Transform (FFT) to the digitized signal. In particular, the FFT can have a resolution ("FFT Size") of 4096 bins in the frequency range from 20 to 20,000 Hz. This allows a sound pressure level value to be assigned to a frequency component (with finite resolution).

[0035] In particular, this restricted range in the sound pressure level-frequency coordinate system improves the perception of lower sound pressure levels within the specified range. This ensures that all drivers hear the warning signal.

[0036] The triangular shape of the range is adapted to the frequency dependence of the perception threshold of older drivers and to the frequency dependence of the loudness of the wind noise. The perception threshold of older people increases with frequency (higher frequencies are harder to hear and need to be louder), while the loudness of the wind noise decreases with frequency (lower frequencies are more heavily masked by the wind noise and need to be louder). At low and high frequencies in the frequency range from 900 to 20,000 Hertz, higher sound pressure levels are therefore required, which is why the triangular shape follows.

[0037] The human ear processes sounds in frequency bands, such as octave bands or third-octave bands. A warning tone (or tone) can be audibly distinguished from background noise if the band sound pressure level (sound pressure level of the at least one tone in a frequency band) in at least one frequency band is at most 6 decibels below the corresponding band sound pressure level (“band sound pressure level”) of the background noise. For high frequency bands, the perception threshold for older people is crucial for the audibility of the at least one tone.

[0038] In a preferred embodiment, the band sound pressure level of a third octave band (or 1 / 3 octave band) of the at least one sound having a center frequency in the frequency range (defined above) is in a range of 50 to 105 decibels.

[0039] In particular, the band sound pressure level of a third octave band of the at least one sound with a central frequency of 1000 Hertz has a band sound pressure level in a range of

[0040] 87.0 to 92.7 decibels, and / or

[0041] - of 1250 Hertz a band sound pressure level in a range of

[0042] 83.4 to 93.7 decibels, and / or

[0043] - of 1600 Hertz a band sound pressure level in a range of

[0044] 81.1 to 94.7 decibels, and / or

[0045] - of 2000 Hertz a band sound pressure level in a range of

[0046] 78.6 to 95.6 decibels, and / or

[0047] - of 2500 Hertz a band sound pressure level in a range of

[0048] 76.9 to 96.6 decibels, and / or

[0049] - of 3150 Hertz a band sound pressure level in a range of

[0050] 75.6 to 97.7 decibels, and / or

[0051] - of 4000 Hertz a band sound pressure level in a range of

[0052] 70.7 to 98.7 decibels, and / or

[0053] - of 5000 Hertz a band sound pressure level in a range of

[0054] 65.5 to 99.7 decibels, and / or

[0055] - of 6300 Hertz a band sound pressure level in a range of

[0056] 61.4 to 100.7 decibels, and / or

[0057] - of 8000 Hertz a band sound pressure level in a range of

[0058] 70.9 to 101.7 decibels, and / or

[0059] - of 10000 Hertz a band sound pressure level in a range of

[0060] 74.7 to 102.7 decibels, and / or

[0061] - of 12500 Hertz a band sound pressure level in a range of

[0062] 84.0 to 103.7 decibels, and / or

[0063] - of 16000 Hertz a band sound pressure level in a range of

[0064] 87.7 to 104.7 decibels.

[0065] By selecting the lower limit for the band sound pressure level, at least one sound in each frequency band stands out audibly from the vehicle noise and is also audible to older people. By selecting the upper limit, hearing damage is avoided. The band sound pressure level can be measured using known methods, in particular using a third-octave band filter.

[0066] Preferably, the frequency range comprises at least one, particularly preferably all or a majority of the, essential frequency component(s) of the at least one sound. A significant frequency component is defined as a frequency component having a sound pressure level above a limit value of 45 decibels.

[0067] Alternatively, significant frequency components could be defined by a sound pressure level above a limit of 40 decibels and / or 50 decibels.

[0068] Therefore, at least a significant frequency component can lie within the described frequency range. Particularly preferably, all or a large portion of the significant frequency components lie within the described frequency range.

[0069] The at least one sound can in particular have frequency components or significant frequency components outside the described frequency range, wherein preferably all or a large part of the significant frequency components lie within the claimed frequency range or sound pressure frequency range.

[0070] In particular, the lowest essential frequency component (fundamental tone or pitch of the at least one sound) is preferably arranged in the frequency range. It is conceivable that higher essential frequency components (overtones, in particular higher overtones) are partially arranged outside the frequency range.

[0071] The pitch or the lowest significant frequency component of the at least one sound is preferably arranged in a frequency range of 1000 to 4000 Hertz (comprising C6 to B7 in musical notation), preferably 1200 to 1800 Hertz (comprising E6 to A6 in musical notation). Anglo-American notation is used.

[0072] Preferably, the sound pressure level of the at least one sound is the sound pressure level at the driver's ear. The sound pressure level can be measured, in particular, using a sound pressure level meter or a sound level meter at the driver's location.

[0073] The sound pressure level can also refer to the sound output device itself. For headphones or headsets, this corresponds, among other things, to the location of the driver's ear.

[0074] Preferably, the sound pressure level of the at least one sound means the sound pressure level of the entire sound, as can be measured, for example, with a microphone.

[0075] Alternatively, it is conceivable that the sound pressure level of the at least one sound refers to the sound pressure level of the, in particular essential, frequency components in the specified frequency range, which can be determined, for example, by a frequency-selective sound pressure level measurement, for example as described above by applying an FFT or other methods known to a person skilled in the art, in particular analog methods.

[0076] It is preferably provided that the evaluation unit is designed to detect a dangerous situation in the surroundings of the vehicle based on the at least one signal from the at least one environmental sensor, wherein the sound emitting device emits the at least one sound upon detection of the dangerous situation. It may happen that the playing of the at least one sound is perceived by a driver in a dangerous situation, but not recognized. An unrecognized sound can distract or confuse a driver in a dangerous situation.

[0077] According to the invention, the evaluation unit is designed to classify a dangerous situation in the environment of the vehicle based on the at least one signal from the at least one environmental sensor at least into a first class, which requires a high level of urgency in the driver's reaction, and into a second class, which requires a low level of urgency in the driver's reaction. Furthermore, the evaluation unit is designed to cause the sound output device to emit a first sound sequence comprising at least one sound when the level of urgency in the reaction is high, and a second sound sequence comprising at least one sound, which is different from the first sound sequence, when the level of urgency in the reaction is low. The at least one sound can be designed as described above.

[0078] A sound sequence is a temporal sequence of identical or different sounds.

[0079] Emitting different sound sequences depending on the urgency of the response leads to a rapid reaction from the driver. This is due, among other things, to the fact that there is no habituation effect with the first sound sequence, since it is only emitted in very critical situations (and therefore rarely). The second sound sequence, in comparison, can be emitted more frequently and alert the driver to less critical situations. It can be estimated that the first sound sequence is emitted on average every 500 driving hours and the second sound sequence every 5 driving hours.

[0080] Depending on the urgency of the reaction, different requirements exist for the corresponding sound sequence.

[0081] The first sequence of sounds, which is emitted when the reaction urgency is high, must result in a quick and targeted reaction even without knowledge of the urgency.

[0082] The second sound sequence, which is emitted when the reaction urgency is low, can be learned by the driver because he hears it more often.

[0083] The first sound sequence should therefore be similar to the second sound sequence so that a driver executes the reaction learned from the second sound sequence upon perceiving the unknown first sound sequence. Particularly if the sound sequences have several different directional patterns for danger in the front area, on the left side, or on the right side, a targeted learned reaction from the second sound sequence can be transferred to the unknown first sound sequence.

[0084] In particular, it can be provided that the pitch of at least one sound and / or the pitch difference between at least two sounds in the first sound sequence is the same as the pitch of at least one sound or the pitch difference between at least two sounds in the second sound sequence. This creates a recognisable relationship between the first sound sequence and the second sound sequence. The first sound sequence should also differ from the second sound sequence so that a driver understands the greater urgency of the reaction even without knowledge of the first sound sequence. Preferably, the first sound sequence should also convey the greater urgency of the reaction on its own, for example for psychoacoustic reasons.

[0085] This problem is addressed by the following working examples.

[0086] In a preferred embodiment, the first sound sequence has a higher sound repetition rate than the second sound sequence. Additionally or alternatively, the first sound sequence can be emitted for longer (over a longer period of time) than the second sound sequence. The first sound sequence therefore has at least one difference from the second sound sequence, so that a driver understands the greater urgency of the reaction even without knowledge of the first sound sequence. In addition, the first sound sequence itself (for psychoacoustic reasons) conveys the high urgency of the reaction, since the sound repetition rate is higher and the emission duration is longer.

[0087] In particular, the first sound sequence may comprise sounds with a sound repetition rate of 7 to 15, preferably 7 to 10, sounds per second.

[0088] The sound repetition rate can be defined as the inverse of the duration between two consecutive sounds. The sound repetition rate can also be defined as the average sound repetition rate, taking into account pauses between successive sound sequences. Additionally or alternatively, the first sound sequence can comprise sounds with a duration between 40 and 50, preferably between 43 and 45, milliseconds.

[0089] Additionally or alternatively, the first sequence of sounds may have a pause of 50 to 60, preferably 55 to 57 milliseconds after each sound.

[0090] Preferably, the evaluation unit is configured to cause the sound output device to repeatedly emit the first sound sequence as long as the evaluation unit determines a high level of urgency for the response based on the signals from the at least one environmental sensor. It can be provided that an intermediate pause lasting 100 to 500 milliseconds, preferably 250 to 350 milliseconds, is present between every second repetition of the first sound sequence.

[0091] Examples of the properties of the second sound sequence (for a low reaction urgency) are given below:

[0092] In particular, the second sound sequence may comprise sounds with a sound repetition rate of 5 to s 8 , preferably 5.3 to s 5.4 , sounds per second.

[0093] Additionally or alternatively, the second sound sequence may comprise sounds with a duration between 80 and 90, preferably between 84 and 86, milliseconds.

[0094] Additionally or alternatively, the second sound sequence may have a pause of 75 to 107, preferably 101 to 103, milliseconds after each sound. The sounds of the second sound sequence may have reverberation. The sound duration and the subsequent pause are defined without taking the reverberation into account.

[0095] Preferably, the evaluation unit is configured to cause the sound-emitting device to emit the second sound sequence only once, as soon as the evaluation unit concludes a low response urgency based on the signals from the at least one environmental sensor. The second sound sequence can also be emitted a few times, but preferably not continuously.

[0096] By playing the second sound sequence only once or only a few times and at a lower repetition rate, the driver is given a sense of urgency to respond without being unduly distracted or confused. Furthermore, there is no habituation effect, as the first sound sequence contrasts with the second.

[0097] Due to the high sound repetition rate and the continuous output, the first sound sequence conveys both relative to the second sound sequence and as such that there is a high urgency to respond.

[0098] As the vehicle approaches an object, the hazardous situation can initially be classified as requiring a low response urgency, and the second sequence of sounds can be emitted. As the vehicle approaches the object further, the hazardous situation can then be classified as requiring a high response urgency, and the first sequence of sounds can be emitted.

[0099] However, it can also happen that a dangerous situation is immediately classified as requiring a high level of urgency, so that the first sequence of sounds is emitted straight away. This can happen, for example, when a dangerous situation occurs suddenly. In a preferred embodiment, the first sequence of sounds and the second sequence of sounds can each have different directional characteristics, depending on whether the evaluation unit, based on the signals from the at least one environmental sensor, concludes that there is a danger in the front area, in the left side area, in the right side area, or in the rear area of ​​the vehicle. A driver can therefore react to a dangerous situation in a targeted manner.

[0100] A separate directional signal can also be emitted when the evaluation unit detects a change in status on the vehicle's dashboard. A sound sequence of this directional signal is intended to entice a driver to look at the dashboard and notice the change, which typically accompanies the illumination of a warning light. Such a status change could, for example, be switching to the reserve tank or a warning of ice danger.

[0101] Preferably, the pitch of at least one sound of the first sound sequence with a directional configuration is equal to the pitch of at least one sound of the second sound sequence with the same directional configuration. In particular, several sounds of the first sound sequence can have pitch-corresponding sounds in the second sound sequence. A pitch difference, in particular a musical interval, of the first sound sequence can also be represented in the second sound sequence.

[0102] This means that the first sound sequence and the second sound sequence of a particular directional pattern are related to each other. In particular, differences in pitch and musical intervals are easily recognizable. A driver can thus recognize the directional pattern of an unknown first sound sequence based on its similarity to the known second sound sequence of the same directional pattern. This allows them to react in a targeted manner when the urgency of the response is high.

[0103] Specific directional sound sequences can be provided for a hazard in the front, left, and / or right side areas. A hazard behind the vehicle or a status change on the dashboard can also trigger a specific directional sound sequence. Examples of directional sound sequences are given below.

[0104] In one embodiment, the evaluation unit is designed to cause the sound emitting device to emit the first sound sequence and / or the second sound sequence with sounds increasing in pitch when the evaluation unit concludes that there is a danger in the front area of ​​the vehicle based on the signals from the at least one environmental sensor.

[0105] The rising tones, due to psychoacoustic effects, guide the driver to look ahead. This alerts the driver to a hazard.

[0106] In addition, the ascending tones have a recognition value. A driver can therefore transfer the reaction to the familiar ascending second tones (looking forward) to the unfamiliar ascending first tones.

[0107] In particular, the first sequence of sounds may comprise three sounds with different pitches, with the pitches preferably being around 1319 Hertz (E6), 1480 Hertz (F#6), and 1568 Hertz (G6). The first sequence of sounds may have a pitch difference of one whole tone and a pitch difference of one semitone.

[0108] In particular, the second sequence of sounds may comprise two sounds with different pitches, the pitches preferably being around 1480 Hertz (F# 6) and 1568 (G6) Hertz.

[0109] The second sequence of sounds can have a pitch difference of one semitone.

[0110] The pitches of the first and second sound sequences correspond at least partially. Both have at least partially the same pitch and share a common pitch difference (semitone interval). This allows a driver to recognize the relationship between the two sound sequences.

[0111] The use of three pitches in the first sound sequence suggests a higher urgency of response than the use of two pitches.

[0112] In one embodiment, the sound output device has a left and a right channel, wherein the evaluation unit is designed to cause the sound output device to output the first sound sequence and / or the second sound sequence mainly on the left or on the right channel if the evaluation unit concludes that there is a danger in the left side area or in the right side area of ​​the vehicle based on the signals from the at least one environmental sensor.

[0113] The left or right channel is preferably perceived primarily or exclusively by the driver's left or right ear, for example, through stereo headphones. This allows for targeted warning of a dangerous situation.

[0114] Preferably, the first and second sound sequences of this directional design can comprise sounds of constant pitch. The warning of danger to the side is thus provided exclusively by the arrangement of the sound sequence in the stereo field. This avoids confusion with the "front" directional design.

[0115] In a preferred embodiment, the at least one environmental sensor is a camera, a distance measuring device and / or a communication device for communication with other vehicles or stationary devices.

[0116] The camera can be a visible-light or infrared camera. A camera can detect a hazardous situation using known methods.

[0117] The distance measuring device can work with radar, sonar, or lidar waves, for example. However, other distance measuring devices are also possible.

[0118] A communication device for communicating with other vehicles or stationary devices can consist of a wireless connection, for example, via microwaves. For example, a convoy of vehicles can connect to each other so that the abrupt braking of a leading vehicle triggers the output of at least one sound or a sequence of sounds on the following vehicle.

[0119] The sound output device can be a helmet speaker, a headset, or a loudspeaker mounted on the vehicle. Preferably, the at least one sound can be transmitted wirelessly to the sound output device, in particular from a sound generation device or from the evaluation unit. A known transmission protocol can be used for this purpose. However, connections via cable are also conceivable, in particular if the loudspeaker is mounted on the vehicle.

[0120] In a preferred embodiment, audio data of the at least one sound or the at least one sound sequence are stored on a preferably digital data carrier, in particular in a time- and value-discrete representation. However, analog data carriers with a continuous representation of the audio data are also conceivable. The data carrier can be arranged on the vehicle or at another location, for example, in the driver's helmet.

[0121] In particular, eight sound sequences can be stored on the data storage device: two sound sequences for a dangerous situation in the front area, two sound sequences for a dangerous situation in the left side area, two sound sequences for a dangerous situation in the right side area, two sound sequences for a dangerous situation in the rear area or for a status change on the dashboard (the latter optional). A first sound sequence can be provided for a high reaction urgency and a second sound sequence for a low reaction urgency.

[0122] Optionally, only four sound sequences can be stored on the data storage device: two sound sequences for a dangerous situation in the front area (a first sound sequence and a second sound sequence, depending on the urgency of the response), one sound sequence for a dangerous situation in the left side area, and one sound sequence for a dangerous situation in the right side area. It can therefore be provided that a distinction is made between the different levels of response urgency only in the case of a dangerous situation in the front area.

[0123] The evaluation unit can be configured to directly cause the sound-emitting device to emit at least one sound. In this case, the evaluation unit can comprise a sound-generating device. A sound-generating device generates the sound signal, which the sound-emitting device converts into a physical sound.

[0124] The sound generating device can alternatively be a stand-alone unit or be housed in another unit, such as a central processing unit of the vehicle or the sound emitting device. The evaluation unit can then indirectly cause the sound emitting device to emit at least one sound.

[0125] The sound generating device can be a reader for reading audio data from a digital or analog data carrier and a converter for converting the audio data into an electrical signal for driving the loudspeakers. Alternatively, the sound generating device can be an analog or digital synthesizer that generates the sound without reading from a memory.

[0126] The evaluation unit can be a control unit of the vehicle that also performs other tasks. However, the evaluation unit can also be installed on the vehicle solely for the described function.

[0127] The open vehicle is preferably a motor-driven vehicle, in particular a motorcycle, a quad bike, a buggy, or a convertible. In motor-driven, open vehicles, the wind is particularly loud due to the high speeds. According to the invention, a computer program product is also provided for warning a driver of an open vehicle, comprising commands which, when the program is executed by an evaluation unit, cause the evaluation unit to

[0128] - to receive signals from at least one environmental sensor, to send or have sent at least one sound to warn the driver to a sound emitting device, wherein the at least one sound has at least one frequency component in a frequency range of 900 to 20,000, in particular 1,000 to 10,000, Hertz.

[0129] It is preferably provided that the at least one sound has a sound pressure level, wherein the sound pressure level lies in a range of 50 to 110 decibels, preferably wherein at least one, particularly preferably all or a large part of the frequency component (s) and the sound pressure level of the at least one sound are arranged within an imaginary range in a sound pressure level-frequency coordinate system, wherein the imaginary range is a triangle with

[0130] - a first corner point at 90 decibels and 900 hertz, and

[0131] - a second corner point at 90 decibels and 20000 Hertz, and

[0132] - a third corner point at 50 decibels and 5000 hertz.

[0133] A computer program product according to the invention comprises instructions which, when the program is executed by an evaluation unit, cause the evaluation unit to

[0134] - to receive signals from at least one environmental sensor,

[0135] - to classify a dangerous situation in the surroundings of the vehicle based on the at least one signal of the at least one environmental sensor into at least a first class, which requires a high degree of urgency of reaction from the driver, and into a second class, which requires a low degree of urgency of reaction from the driver,

[0136] - if the reaction is urgent, at least a first

[0137] to send or have sent a sound sequence comprising at least one sound to a sound emitting device,

[0138] - in the case of a low reaction urgency, to send or have sent at least one second sound sequence different from the first sound sequence comprising at least one sound to a sound emitting device.

[0139] Further embodiments and details are shown in the figures.

[0140] Fig. 1a Sound pressure level-frequency diagram with the volume of the wind, the hearing damage limit and the perception limit for older people

[0141] Fig. 1b Sound pressure level-frequency diagram as in Fig. 1a with a restricted imaginary range for the sound pressure and the frequency of the sound

[0142] Fig. 2 Sound pressure level-frequency diagram as in Fig. 1b with perception limit for earplug-wearing drivers and maximum volume of a tested

[0143] Sound emitting device

[0144] Fig. 3 Sound pressure level-frequency diagram with the

[0145] Frequency spectrum of a sound sequence

[0146] Fig. 4 Band sound pressure level ranges of different third octave bands and band sound pressure levels of a sound sequence

[0147] Fig. 5a Waveform of an example of the first sound sequence

[0148] Fig. 5b Notation of an embodiment of the first

[0149] Sound sequence

[0150] Fig. 6a Waveform of an embodiment of the second

[0151] Sound sequence Fig . 6b Notation of an example of the second sound sequence

[0152] Fig. 7 Areas around the vehicle perceived by the environmental sensor

[0153] Fig. 8 Vehicle with driver and warning system

[0154] Fig. 1a shows a sound pressure level-frequency diagram with a sound pressure level-frequency coordinate system 7. The frequency in Hertz is plotted logarithmically in the audible range on the abscissa. The sound pressure level in decibels is plotted on the ordinate. The sound pressure level values ​​were determined using a Fast Fourier Transform (FFT) with a resolution ("FFT Size") of 4096 bins in the frequency range from 20 to 20,000 Hz. The "peak hold" value of the sound pressure level is given, that is, the peak value of the sound pressure level at any given time (without averaging over time).

[0155] In the coordinate system 7, the frequency-dependent sound pressure level of the airstream A is shown as a continuous line, the hearing damage limit B as a dashed line and the perception limit for older people C as a dash-dotted line (with two points).

[0156] The sound pressure level of the airstream was determined by means of tests. A microphone was mounted in a helmet to measure the sound pressure level at the driver's ear.

[0157] In a wind tunnel, various air speeds from 30 to 140 kilometers per hour were set and analyzed. Riders were placed in a wind tunnel wearing different types of helmets (full-face helmet or flip-up helmet with raised or lowered chin guard, shell helmet with visor or with goggles). For all air speeds, the rider's head was placed in different positions (looking to the left, looking straight, looking to the right, looking over the shoulder to the left, looking over the shoulder to the right).

[0158] Body positions were varied (upright, leaning forward).

[0159] In addition, the sound pressure level of the wind on the road was measured for different scenarios (country roads, motorways, city streets, tunnels), with the test vehicles being motorcycles and being used with or without a windshield.

[0160] The sound pressure level was measured in each case and its frequency dependence was analyzed. The results are plotted as loudness A.

[0161] The sound pressure level of the airstream A decreases with higher frequencies. A sound 5 used to warn the driver should therefore contain frequency components in the higher frequency range. Furthermore, a sound 5 should not be too loud to avoid permanent hearing damage (below line B).

[0162] Depending on at least one signal from the at least one environmental sensor 2, the evaluation unit 3 can cause a sound emitting device 4 to emit at least one sound 5 to warn the driver 6 of the vehicle, wherein the at least one sound 5 has at least one or all or a majority of the frequency components (e) in a frequency range from 900 to 20,000 Hertz. This frequency range is shown in Fig. 1a.

[0163] The at least one sound has a sound pressure level, wherein the sound pressure level preferably lies in a range of 50 to 90 decibels. These values ​​are also shown in Fig. 1a.

[0164] This sound pressure level-frequency range corresponds to a rectangular, imaginary range 8 in the sound pressure level-frequency coordinate system 7 . The range is located below the threshold for hearing impairment B , so that (permanent) hearing damage is avoided. Furthermore, the range is located at such high frequencies that the volume of the airstream A has already decreased somewhat. Normally, such a sound 5 can be easily perceived while driving.

[0165] Fig. 1b shows the sound pressure level-frequency coordinate system 7 from Fig. 1a. In addition, a restricted, improved imaginary region 8 is shown in the sound pressure level-frequency coordinate system 7. The imaginary region 8 is a triangle with a first corner point 9 at 90 decibels and 900 Hertz, a second corner point 10 at 90 decibels and 20,000 Hertz, and a third corner point 11 at 50 decibels and 5,000 Hertz.

[0166] Sounds 5 with frequency components and a sound pressure level in this restricted range 8 are, on the one hand, more audible for older people, since the range 8 is completely above the perception limit C for older people. On the other hand, the range 8 is completely above the volume of the airstream A, so that a sound 5 with a sound pressure level and frequency components in this range 8 is more audible. Overall, a sound 5 with a sound pressure level and frequency components within the range 8 from Fig. 1b is clearly audible for all people and in all driving situations.

[0167] It should be noted again that the range is determined for the peak hold sound pressure level, which was calculated using an EFT with a resolution of 4096 bins.

[0168] The range may take other values, for example the value of the sound pressure level a band sound pressure level , in particular a third-octave band (as in Fig . 4 ) .

[0169] Fig. 2 shows the sound pressure level-frequency coordinate system 7 from Figures 1a and 1b with two additional lines D and E. On the one hand, the perception limit E for drivers with earplugs is shown as a thin, dash-dotted line. Sound pressure levels above this perception limit E are clearly audible even with earplugs. This perception limit E does not intersect the imaginary area 8 in the sound pressure level-frequency coordinate system 7 of the sound 5, so it is not considered further.

[0170] On the other hand, the maximum sound pressure level D of a tested sound output device 4 is shown as a thick dash-dotted line. The tested sound output device 4 is a typical helmet intercom which can be controlled wirelessly. Other sound output devices 4 were also tested and produced similar results. The frequency components and the sound pressure level of a sound 5 are preferably arranged below the line of the maximum sound pressure level D of the tested sound device 4 (shaded area), especially since the sound 5 can be unpleasant at higher frequencies and requires other technical means. However, it is conceivable to provide a sound 5 above this line using a suitable sound output device 4, since this limitation does not describe the perceptibility or harmfulness of the sound 5, but merely the technical limitation of a typical system.

[0171] Figure 3 shows a sound pressure level-frequency diagram with the frequency spectrum of a sound sequence. In particular, the imaginary region 8 is shown in the sound pressure level-frequency coordinate system 7 of Figures 1b and 2.

[0172] The frequency spectrum of the sound sequence, like the lines in Figures 1a, 1b, and 2, was generated using an FFT with a resolution of 4096 bins over a frequency range of 20 to 20,000 Hz. These are peak-hold values ​​of the sound pressure level (without temporal averaging).

[0173] The peaks of the frequency spectrum of at least one sound 5, and thus its (essential) frequency components, are all located in the imaginary range 8.

[0174] The illustrated sound sequence is, in particular, the first sound sequence 15, specifically the one for a high reaction urgency in the front area of ​​the vehicle. Sound sequence 15 is composed of three sounds 5, each of which also has peaks in the imaginary area 8.

[0175] Fig. 4 shows band sound pressure level ranges of different third-octave bands and band sound pressure levels of a sound sequence, in particular the first sound sequence 15 as in Fig. 3.

[0176] The center frequencies of the respective third-octave bands are plotted on the abscissa and the band sound pressure level on the ordinate.

[0177] The bright band sound pressure level ranges represent the permitted band sound pressure level range for the respective third-octave band. The black diamond shows the band sound pressure levels of the first sound sequence 15.

[0178] The first sound sequence 15 has significant frequency components in the third-octave bands with center frequencies of 1600, 2000, 2500, 3150, 4000, 5000, and 6300. The band sound pressure level in each of these third-octave bands is approximately 90.3 decibels. This value is higher than the peak values ​​in Fig. 3, which are all below 90 decibels, as they refer to other, particularly larger, frequency ranges (Fig. 4: third-octave bands, Fig. 3: 4096 FFT bins). The maximum band sound pressure level (so that no hearing damage occurs) and the minimum band sound pressure level (so that sounds 5 are perceptible despite vehicle noise and age-related hearing) can be found in the following table: The sound emitting device 4 can emit a sound sequence 15, 16 comprising at least one sound 5. The sound sequence 15, 16 can be selected depending on the type of dangerous situation. In particular, the dangerous situation in the environment of the vehicle 1 can be classified by the evaluation unit 3 based on the at least one signal from the at least one environmental sensor 2 at least into the classes "low reaction urgency" and "high reaction urgency". In the case of a high reaction urgency, the output of a first sound sequence 15 is initiated, and in the case of a low reaction urgency, the output of a second sound sequence 16 different from the first sound sequence is initiated.

[0179] In addition, depending on the direction of the danger zone relative to vehicle 1, the first sound sequence 15 and the second sound sequence 16 can be varied (different directional configurations). A preferred embodiment of the most important sound sequences

[0180] 15 , 16 is given below :

[0181] In addition, directional signals can be provided for a dangerous situation in the rear area and a status change on the dashboard.

[0182] Figures 5a and 5b show characteristics of an exemplary embodiment of a first sound sequence 15. In particular, this is a sound sequence 15 with a directional pattern intended to indicate a dangerous situation in the front area of ​​the vehicle 1.

[0183] Fig. 5a shows the waveform of the first sound sequence 15 on the left channel L and the right channel R. This represents the directional signal for a dangerous situation in the front area 21 of the vehicle 1; the sounds 5 are arranged centrally in the stereo field.

[0184] The sounds 5 have a sound repetition rate of approximately 10 sounds 5 per second. The sound repetition period 20 is approximately 100 milliseconds. The sound repetition rate 20 is defined here as the repetition rate between two adjacent sounds 5 within the first sound sequence 15 (without taking into account intermediate pauses 19), as the inverse of the sound repetition period 20. The sound repetition period 20 is the duration between two sound start times.

[0185] An average sound repetition rate, including the intermediate pause 19, is somewhat lower (6.7 sounds per second). The sounds 5 of the first sound sequence 15 have a sound duration 17 of between 40 and 50, preferably between 43 and 45, milliseconds. After each sound 5, a pause 18 of 50 to 60, preferably 55 to 57, milliseconds is provided.

[0186] Fig. 5b shows the notation of several consecutive first sound sequences 15 in the directional configuration for a dangerous situation in the front area 21 of the vehicle 1. In particular, the pitches of the sounds 5 are notated. In this exemplary embodiment, the sound sequence 15 has the pitches E6 (1318.51 Hz 1319 Hz), F#6 (1479.98 Hz 1480 Hz) and G6 (1567.98 Hz 1568 Hz) in order.

[0187] It can also be seen that after two sound sequences 15 there is an intermediate pause 19, after which two more sound sequences 15 followed by an intermediate pause 19 are emitted, and so on.

[0188] The rising pitches cause a driver to look forward, which is desirable in a dangerous situation in the front area 21. The pitches are also similar to the second sound sequence 16, which is shown below.

[0189] Fig. 6a shows the waveform of the second sound sequence 16 on the left channel L and the right channel R. This is the directional formation for a dangerous situation in the front area 21 of the vehicle 1, the sounds 5 are arranged essentially centrally in the stereo field.

[0190] The sounds 5 of the second sound sequence 16 have a sound repetition rate of 5 to 6, preferably 5.3 to 5.4, sounds 5 per second. This corresponds to a sound repetition period 20 of approximately 187 milliseconds. The sound repetition rate is therefore greater than that of the first sound sequence 15, whereby the first sound sequence 15 signals a higher response urgency than the second sound sequence 16.

[0191] The sounds 5 of the second sound sequence 16 have a sound duration 17 between 80 and 90, preferably between 84 and 86, milliseconds.

[0192] After the sounds 5 of the second sound sequence 16, there is a pause 18 of 97 to 107, preferably 101 to 103, milliseconds. In this case, there is only one pause 18, since the sound sequence 16 consists of only two sounds 5 and is played only once.

[0193] It is also evident from Fig. 6a that sounds 5 exhibit reverberation. The duration of the sounds and the pauses are given without taking reverberation into account.

[0194] Fig. 6b shows the notation of the second sound sequence 16 in the directional form for a dangerous situation in the front area 21 of the vehicle 1. In particular, the pitches of the sounds 5 are notated. In this exemplary embodiment, the sound sequence 15 has the pitches F# 6 (1479.98 Hz ~ 1480 Hz) and G6 (1567.98 Hz ~ 1568 Hz), i.e., a semitone step.

[0195] These tones are also included in the first sound sequence 15 . A driver can therefore get used to the more frequently sounded second sound sequence 16 for dangerous situations with a low reaction urgency. For example, he can learn to look ahead. Due to the relationship to the first sound sequence (two identical pitches, one identical semitone interval) a driver can quickly carry out this learned reaction even in a dangerous situation with a high reaction urgency. Fig. 7 shows the areas around the vehicle 1 perceived by the environmental sensor 2 (see Fig. 8) of the vehicle. In particular, a distinction is made between a front area 21, a left side area 22, a right side area 23 and a rear area 24.

[0196] The first sound sequence 15 and the second sound sequence 16 each have different directional formations, depending on whether the evaluation unit 3 concludes, on the basis of the signals from the at least one environmental sensor 2, that there is a danger in the front area 21 or in the left side area 22 or in the right side area 23 or in the rear area 24 of the vehicle 1.

[0197] The sound sequences 15, 16 described in Figures 5a to 6b are suitable for indicating the direction of a dangerous situation in the front area 22.

[0198] In the side areas 22, 23, the sound sequences can be played primarily on the left channel L and the right channel R, respectively. The pitch can be constant. Otherwise, the same sound repetition rates 20, sound durations 17, and pauses 18, 19 can be provided for the first sound sequence and the second sound sequence, respectively.

[0199] When information is first displayed on the dashboard, for example, upon detection of an empty main tank or a risk of ice, descending tone sequences can be used. This encourages the driver to look down at the dashboard.

[0200] Fig. 8 shows an open vehicle 1 in the form of a motorcycle with a driver 6. In the helmet of the driver 6 is a

[0201] A sound output device 4, for example a headset, is arranged. An evaluation unit 3 interprets signals from an environmental sensor 2 to classify a dangerous situation. In particular, the urgency of the reaction (low, high) and the location of the dangerous situation (front area 21, left side area 22, right side area 23, rear area 24,

[0202] Status change on the dashboard 25). Depending on the classification, the evaluation unit 3 causes the sound output device 4 to play a first sound sequence 15 or a second sound sequence 16 or a sound 5. The sound sequence 15, 16 can be generated by a sound generating device 14, which

[0203] Reads sound sequence 15, 16 from a data carrier (not shown).

[0204] The sound generating device 14 is arranged in the evaluation unit 3 in Fig. 8, but it can also be arranged elsewhere on the vehicle 1 or on the helmet.

[0205] Reference symbol list

[0206] 1 open vehicle

[0207] 2 Environmental sensor

[0208] 3 Evaluation unit

[0209] 4 Sound emitter

[0210] 5 Kang

[0211] 6 drivers

[0212] 7 Sound pressure level frequency coordinate system

[0213] 8 imaginary area in the sound pressure level-frequency coordinate system

[0214] 9 first corner point

[0215] 10 second corner point

[0216] 11 third corner point

[0217] 12 significant frequency component

[0218] 13 Maximum sound pressure level

[0219] 14 Sound generating device

[0220] 15 first sound sequence

[0221] 16 second sound sequence

[0222] 17 sound duration

[0223] 18 breaks

[0224] 19 Intermediate break

[0225] 20 sound repetition period

[0226] 21 Front area

[0227] 22 left side area

[0228] 23 right side area

[0229] 24 Rear area

[0230] 25 Dashboard

[0231] L left channel

[0232] R right channel

[0233] A Volume of the wind

[0234] B Hearing damage limit

[0235] C Perception limit of older people

[0236] D maximum volume of a tested sound emitting device

[0237] E Perception limit with earplugs

Claims

Patent claims 1. Open vehicle (1) with at least one environmental sensor (2) and an evaluation unit (3), wherein the evaluation unit (3) is designed to cause a sound emission device (4) to emit at least one sound (5) for warning the driver (6) of the vehicle (1) depending on at least one signal from the at least one environmental sensor (2), characterized in that the at least one sound (5) has at least one frequency component in a frequency range of 900 to 20,000, in particular 1,000 to 10,000, Hertz.

2. Open vehicle (1) according to the preceding claim, wherein the at least one sound (5) has a sound pressure level, the sound pressure level being in a range of 50 to 110 decibels.

3. Open vehicle (1) according to claim 1 or 2, wherein at least one, preferably all or a majority of the frequency component (e) and the sound pressure level of the at least one sound are arranged within an imaginary area (8) in a sound pressure level-frequency coordinate system (7), wherein the imaginary area forms a triangle with - a first corner point (9) at 90 decibels and 900 hertz, and - a second corner point (10) at 90 decibels and 20,000 hertz, and - a third corner point (11) at 50 decibels and 5000 hertz.

4. Open vehicle (1) according to one of the preceding Claims, wherein the band sound pressure level of a third octave band of the at least one sound with a center frequency in the frequency range in a range of 50 to 105 decibels, in particular wherein the band sound pressure level of a third octave band of the at least one sound with a center frequency - has a band sound pressure level of 1000 Hertz in a range of 87.0 to 92.7 decibels, and / or - of 1250 Hertz a band sound pressure level in a range of 83.4 to 93.7 decibels, and / or - of 1600 Hertz a band sound pressure level in a range of 81.1 to 94.7 decibels, and / or - of 2000 Hertz a band sound pressure level in a Range of 78.6 to 95.6 decibels, and / or - of 2500 Hertz a band sound pressure level in a Range from 76.9 to 96.6 decibels, and / or - of 3150 Hertz a band sound pressure level in a Range of 75.6 to 97.7 decibels, and / or - of 4000 Hertz a band sound pressure level in a range of 70.7 to 98.7 decibels, and / or - of 5000 Hertz a band sound pressure level in a range of 65.5 to 99.7 decibels, and / or - of 6300 Hertz a band sound pressure level in a range of 61.4 to 100.7 decibels, and / or - of 8000 Hertz a band sound pressure level in a range of 70.9 to 101.7 decibels, and / or - of 10000 Hertz a band sound pressure level in a range of 74.7 to 102.7 decibels, and / or - of 12500 Hertz a band sound pressure level in a range of 84.0 to 103.7 decibels, and / or - of 16000 Hertz a band sound pressure level in a Range from 87.7 to 104.7 decibels.

5. Open vehicle (1) according to one of the preceding claims, wherein the evaluation unit (3) is designed to detect a dangerous situation in the surroundings of the vehicle (1) based on the at least one signal of the at least one environmental sensor (2), wherein the sound emitting device (4) emits the at least one sound (5) upon detection of the dangerous situation.

6. An open-top vehicle (1) with at least one environmental sensor (2) and an evaluation unit (3), in particular according to one of the preceding claims, characterized in that the evaluation unit (3) is designed to classify a dangerous situation in the environment of the vehicle (1) based on the at least one signal from the at least one environmental sensor (2) at least into a first class, which requires a high reaction urgency of the driver (6), and into a second class, which requires a low reaction urgency of the driver (6), wherein the evaluation unit (3) is designed to cause the sound output device (4) to emit a first sound sequence (15) comprising at least one sound (5) in the case of a high reaction urgency and a second sound sequence (16) comprising at least one sound (5) which is different from the first sound sequence (15) and in the case of a low reaction urgency.

7. Open vehicle (1) according to the preceding claim, wherein the pitch of at least one sound (5) and / or the pitch difference of at least two sounds (5) of the first sound sequence (15) is the same as the pitch of at least one sound (5) or the pitch difference of at least two sounds (5) of the second sound sequence (16).

8. Open vehicle (1) according to claim 6 or 7, wherein the first sound sequence (15) has a greater sound repetition rate than the second sound sequence (16) and / or wherein the first sound sequence (15) is emitted longer than the second sound sequence (16).

9. Open vehicle according to claim 6 to 8, wherein the first sound sequence (15) - Sounds (5) with a sound repetition rate of 7 to 15, preferably 7 to 10, sounds (5) per second, and / or - sounds (5) with a sound duration (17) between 40 and 50, preferably between 43 and 45, milliseconds, and / or - after each of the sounds (5) there is a pause (18) of 50 to 60, preferably 55 to 57 milliseconds.

10. Open vehicle (1) according to one of claims 6 to 9, wherein the evaluation unit (3) is designed to cause the sound output device (4) to repeatedly output the first sound sequence (15) as long as the evaluation unit (3) concludes a high reaction urgency based on the signals of the at least one environmental sensor (2), preferably wherein between every second repetition of the first sound sequence (15) there is an intermediate pause (19) with a duration of 100 to 500 milliseconds, preferably 250 to 350 milliseconds.

11. Open vehicle (1) according to one of claims 6 to 10, wherein the second sound sequence (16) - Sounds (5) with a sound repetition rate of 5 to 8, preferably 5.3 to 5.4, sounds (5) per second, and / or - sounds (5) with a sound duration (17) between 80 and 90, preferably between 84 and 86, milliseconds, and / or - after the sounds (5) a rest (18) from 75 to 107, preferably 101 to 103, milliseconds.

12. Open vehicle (1) according to one of claims 6 to 11, wherein the evaluation unit (3) is designed to cause the sound emitting device (4) to emit the second sound sequence (16) only once, as soon as the evaluation unit (3) has responded to a low Response urgency closes.

13. Open vehicle (1) according to one of claims 6 to 12, wherein the first sound sequence (15) and the second sound sequence (16) each have different directional formations, depending on whether the evaluation unit (3) concludes, on the basis of the signals from the at least one environmental sensor (2), that there is a danger in the front area (21) or in the left side area (22) or in the right side area (23) or in the rear area (24) of the vehicle (1) or depending on whether the evaluation unit (3) detects a change in a status on the dashboard (25) of the vehicle (1).

14. Open vehicle (1) according to the preceding claim, wherein the pitch of at least one sound (5) or the pitch difference of at least two sounds (5) of the first sound sequence (15) with a directional shape is the same as the pitch of at least one sound (5) or the pitch difference of at least two sounds (5) of the second sound sequence (16) with the same directional shape.

15. Open vehicle (1) according to one of claims 6 to 14, wherein the evaluation unit (3) is designed to cause the sound output device (4) to output the first sound sequence (15) and / or the second sound sequence (16) with sounds (5) increasing in pitch when the evaluation unit (3) concludes that there is a danger in the front area (21) of the vehicle (1) based on the signals from the at least one environmental sensor (2).

16. Open vehicle (1) according to one of claims 6 to 15, wherein - the first sound sequence (15) comprises three sounds (5) with different pitches, preferably with the pitches being around 1319 Hertz, 1480 Hertz and 1568 Hertz, and / or - the first sound sequence (15) has a pitch difference of one whole tone and a pitch difference of one semitone, and / or - the second sound sequence (16) comprises two sounds (5) with different pitches, preferably with the pitches being around 1480 Hertz and 1568 Hertz, and / or - the second sound sequence (16) has a pitch difference of one semitone.

17. Open vehicle (1) according to one of claims 6 to 16, wherein the sound output device (4) has a left channel (L) and a right channel (R), wherein the evaluation unit (3) is designed to cause the sound output device (4) to output the first sound sequence (15) and / or the second sound sequence (16) mainly on the left channel (L) or on the right channel (R) when the evaluation unit (3) detects a danger in the left side area (22) or in the right side area (23) of the vehicle based on the signals of the at least one environmental sensor (2). Vehicle (1), preferably wherein the first sound sequence (15) and the second sound sequence (16) comprise sounds (5) with a constant pitch.

18. Open vehicle (1) according to one of the preceding claims, wherein the at least one environmental sensor (2) is a camera, a distance measuring device, in particular a lidar system, and / or a communication device for communication with other vehicles or stationary devices.

19. Open vehicle (1) according to one of the preceding claims, wherein the sound output device (4) is a helmet loudspeaker, a headset or a loudspeaker arranged on the vehicle, preferably wherein the at least one sound (5) can be sent wirelessly to the sound output device (4), in particular from a sound generating device (14) or from the evaluation unit (3).

20. Open vehicle (1) according to one of the preceding claims, wherein audio data of the at least one sound (5) or of the at least one first and second sound sequence (15, 16) are stored on a, preferably digital, data carrier, in particular in a time- and value-discrete representation, particularly preferably wherein the data carrier is arranged on the vehicle (1).

21. Open vehicle (1) according to one of the preceding Claims, wherein the vehicle (1) is a motor-driven vehicle, in particular a motorcycle, a quad, a buggy or a convertible.

22. Computer program product for warning a driver (6) of an open vehicle (1), in particular according to one of claims 1 to 21, comprising commands which, when the program is executed by an evaluation unit (3), cause the evaluation unit (3) to - to receive signals from at least one environmental sensor (2), - to send or have sent at least one sound to a sound emitting device (4) to warn the driver (6), wherein the at least one sound (5) has at least one frequency component in a frequency range of 900 to 20,000, in particular 1,000 to 10,000, Hertz.

23. Computer program product according to the preceding claim, wherein the at least one sound (5) has a sound pressure level, wherein the sound pressure level is in a range of 50 to 110 decibels, preferably wherein at least one, particularly preferably all or a majority of the frequency component (e) and the sound pressure level of the at least one sound are arranged within an imaginary area (8) in a sound pressure level-frequency coordinate system (7), wherein the imaginary area is a triangle with - a first corner point (9) at 90 decibels and 900 hertz, and - a second corner point (10) at 90 decibels and 20,000 hertz, and - a third corner point (11) at 50 decibels and 5000 hertz.

24. Computer program product, in particular according to claim 22 or 23, for warning a driver (6) of an open vehicle (1), in particular according to one of claims 1 to 21, comprising commands which, when the program is executed by an evaluation unit (3), cause the evaluation unit (3) to - to receive signals from at least one environmental sensor (2), - to classify a dangerous situation in the surroundings of the vehicle (1) based on the at least one signal of the at least one environmental sensor (2) at least into a first class, which requires a high reaction urgency of the driver (6), and into a second class, which requires a low reaction urgency of the driver (6), - in the case of a high reaction urgency, to send or have sent at least a first sound sequence (15) comprising at least one sound (5) to a sound emitting device (4), - in the case of a low reaction urgency, to send or have sent at least one second sound sequence (16) different from the first sound sequence (15) comprising at least one sound (5) to a sound emitting device (4).

25. Computer-readable medium on which a Computer program product according to one of claims 21 to 24.

26. A data carrier signal carrying a computer program product according to any one of claims 21 to 24.

Images