Method for operating an audio system of a vehicle and audio system

Abstract

The invention relates to a method for operating an audio system (1) of a vehicle. According to the invention, the active states (A1 to An) of the audio sources (10.1 to 10. N) are monitored by a logic-based controller (9.1), and at least one loudspeaker channel (3, 4) associated with the digital audio output stage (16) is deactivated if all audio sources (10.1 to 10. N) are inactive. The invention also relates to an audio system (1) for a vehicle.

Description

[0001] The present invention relates to a method for operating an audio system of a vehicle.

[0002] The present invention also relates to an audio system for a vehicle as recited in the preamble of claim 8.

[0003] DE 198 15 923A1 discloses a control device for an audio amplifier for reducing the interference effects of an audio signal to be reproduced. When interference effects occur in the audio signal to be reproduced, the control device reduces the power of the audio amplifier to reduce the reproduction volume of the audio signal. After the interference effects on the audio signal to be reproduced have disappeared, the control device increases the power of the audio amplifier to the value set before the reduction.

[0004] Furthermore, US2017 / 0250654 A1 discloses a method and a device for dynamically managing the dead time between the turn - on of transistors in an output power stage in an audio amplifier. In this case, a drive signal is generated based on an input signal, wherein the drive signal is amplified by alternately controlling a first transistor and a second transistor, and there is a period of time between the deactivation of the first transistor and the activation of the second transistor. During amplification, the time is set based on a parameter of the input signal or the drive signal. The parameter is the amplitude of the input signal, the duty cycle of the drive signal, or the duty cycle of a pulse - width - modulated signal generated based on the input signal. The input signal is a digital audio input signal.

[0005] DE 10 2021 003 593 A1 discloses an audio system that is deactivated to save energy in the absence of an audio signal or a mute command. US2019 / 0007777 A1 discloses an audio system that switches between two modes based on seat occupancy.

[0006] The object of the present invention is to provide a novel method for operating an audio system of a vehicle and a novel audio system for a vehicle.

[0007] According to the present invention, this object is achieved by a method having the features of claim 1 and an audio system having the features of claim 8.

[0008] Advantageous embodiments of the present invention are the subject matter of the dependent claims.

[0009] In a method for operating an audio system of a vehicle, according to the present invention, the active state of an audio source is monitored by a logic - based controller, and in the case where all audio sources assigned to at least one speaker channel are inactive, the at least one speaker channel of the digital audio output stage is deactivated.

[0010] In the audio entertainment systems in today's vehicles, in addition to the acoustic output of classic entertainment content such as radio content, sound design and the acoustic output of audio signals assigned to various vehicle functions are also performed, such as the sound from the direction indicator of travel, warning sounds, the sound from the parking assistance device, etc. Since a large number of speakers are installed in or on the vehicle, even if not all speaker channels are required, the audio amplifier of the audio entertainment system consumes energy. This is because, for example, by using a so-called audio programming platform, audio signals are generated on the audio output stage itself and transmitted to another amplifier system or speaker for reproduction, where the conversion modules used here, namely in particular the digital-to-analog converter and the audio output stage, cause power losses even in the case of unused audio outputs, i.e., when the signal content is zero. Although completely turning off the audio output stage, including its power supply, offers great savings potential, this only allows all speaker channels to be deactivated.

[0011] In contrast, the present method allows, based on the current system state in the vehicle, to very dynamically turn on and off speaker channels during runtime through complex logical conditions, thus achieving energy savings in the case of unnecessary speaker channels. However, enabling and disabling speaker channels takes time, thus interfering with the response behavior during audio signal reproduction, which may lead to audible audio artifacts. Based on considering the activity of the audio source, in particular in addition to considering the signal content of the audio signal to be output, the present method allows for the predictive deactivation and activation of speaker channels, such that audible audio artifacts and the "swallowing" of sounds can be effectively avoided during activation. Thus, from the user's perspective, the functionality of the audio system is not impaired. Therefore, energy consumption can be reduced during the actual operation of the vehicle without imposing any restrictions on the vehicle's users. In particular, the method can be implemented through a flexibly adaptable software. That is, the safety of eliminating audio artifacts is increased because the software components can be programmed by the vehicle manufacturer within the sound functions. This also makes it possible to differently handle the deactivation of speaker channels in a simple manner between different vehicle series or different audio systems.

[0012] In a possible design of the method, the audio signals of the active audio sources are bundled on at least one speaker channel. As a result of such bundling, for example, the audio signals processed on rarely used speaker channels can be transmitted to other speaker channels, such that the rarely used speaker channels can be deactivated.

[0013] In another possible design of the method, when monitoring the activity status of the audio source, the driving state parameters of the vehicle and / or the operating parameters of the vehicle and / or the operating parameters of the vehicle system are taken into account. This makes it possible to evaluate which audio signals or which audio content must be reproduced, such that in a particularly advantageous manner, only the speaker channels that are considered particularly unlikely to be used in the currently detected situation are deactivated. For example, in the case where the vehicle is traveling at a speed of more than 30 km / h, it is not necessary to output a signal tone from the parking assist device, such that even if other audio sources using these speaker channels are also inactive, the speaker channels for outputting these signal tones can be deactivated.

[0014] In another possible design of the method, when a speaker channel is deactivated, the speaker channel is first muted and then the amplifier module located in the speaker channel is deactivated. This makes it possible to avoid audible interference noises, such as crackling or popping sounds, when the corresponding speaker channel is deactivated.

[0015] In another possible design of the method, in the enabled state, the audio signal output by the coupled audio source is amplified by the amplifier module located in the speaker channel. This allows for the individual amplification of the audio signals of each speaker channel.

[0016] In another possible design of the method, for each enabled speaker channel, the received digital audio signal is converted into an analog audio signal by pulse width modulation before being forwarded to the corresponding speaker. This makes it possible to process the digital audio signal and output the analog audio signal.

[0017] In another possible design of the method, the speaker channel is muted by deactivating the pulse width modulation. This represents an easy-to-implement and reliable deactivation.

[0018] An audio system for a vehicle, comprising a plurality of audio sources and at least one digital audio output stage coupled to the audio sources and having a plurality of speaker channels. In this case, the speaker channels respectively amplify the audio signals output by at least one audio source and transmit the amplified audio signals to at least one coupled speaker.

[0019] According to the present invention, there is provided at least one control unit having a logic-based controller, wherein the control unit is configured to monitor the activity status of the audio sources and, in the case where all the audio sources assigned to at least one speaker channel are inactive, deactivate the at least one speaker channel.

[0020] The audio system allows for very dynamic opening and closing of speaker channels during operation based on complex logical conditions of the current system state in the vehicle, thereby achieving energy savings in the case of unwanted speaker channels. However, enabling and disabling the speaker channels takes time, which interferes with the response behavior during audio signal reproduction and may result in audible audio artifacts. However, since the activity of the audio source is considered, especially in addition to considering the signal content of the audio signal to be output, the audio system allows for predictive disabling and enabling of the speaker channels, such that audible audio artifacts and "swallowing" of sound can be effectively avoided upon enabling. Thus, from the user's perspective, the functionality of the audio system is not impaired. Therefore, energy consumption can be reduced during the actual operation of the vehicle without imposing any restrictions on the vehicle's users. In particular, the disabling function of the speaker channels can be implemented by a flexibly adaptable software. That is, the safety of eliminating audio artifacts is increased because the software component can be programmed by the vehicle manufacturer within the sound function. This also enables different handling of the disabling of speaker channels in different vehicle series or different audio systems in a simple manner.

[0021] In a possible design of the audio system, the control unit is also configured to bundle the audio signals of the active audio sources on at least one speaker channel. As a result of such bundling, for example, the audio signals processed on the rarely used speaker channels can be transmitted to other speaker channels, such that the rarely used speaker channels can be disabled.

[0022] Embodiments of the present invention are explained in more detail below with reference to the accompanying drawings.

[0023] In the drawings:

[0024] Figure 1 A block diagram of an audio system for a vehicle is schematically shown.

[0025] Figure 1 A block diagram of an audio system 1 for a vehicle is shown.

[0026] The audio system 1 includes a distribution module 2, two speaker channels 3, 4, a digital audio output stage 16 having two amplifier modules 5, 6, two speakers 7, 8, a control unit 9, and a plurality of audio sources 10.1 to 10.n. In addition, the audio system includes a data source 11 for the driving state parameter F of the vehicle, a data source 12 for the special operation parameter B of the vehicle and / or the vehicle system, and a data source 13 for transmitting the active states A1 to An of the audio sources 10.1 to 10.n to the control unit 9. Muting devices 14, 15 are respectively arranged in the speaker channels 3, 4.

[0027] In the audio system 1, the audio processing software implemented in the distribution module 2 distributes the audio content to be output from the audio sources 10.1 to 10.n and to be played back to the different speaker channels 3, 4 present in the vehicle. In embodiments not shown in more detail, different numbers of speaker channels 3, 4 and speakers 7, 8 are possible, different from the two speaker channels 3, 4 shown for the purpose of explaining the audio system 1. The audio content is converted into an electrical signal and amplified so that the speakers 7, 8 can radiate the corresponding sound. This amplification takes place in the amplifier modules 5, 6, where these amplifier modules incur power losses even without an audio signal for amplification. However, in the deactivated state of the amplifier modules 5, 6, the amplifier modules do not incur power losses.

[0028] The activation and deactivation of the amplifier modules 5, 6 can be achieved via different paths and allow different energy-saving potentials depending on the path. In this case, the entire audio output stage 16 can be activated or deactivated, or, as may be possible in the case of a digital audio output stage 16, pulse-width modulation can be activated or deactivated, by means of which the digital audio signals output from the audio sources 10.1 to 10.n are converted into analog audio signals before being transmitted to the corresponding speakers 7, 8. While the activation and deactivation of the entire audio output stage 16 generally relate to multiple speaker channels 3, 4, in the case of a digital audio output stage 16, the activation and deactivation of pulse-width modulation allows for the individual activation and deactivation of each speaker channel 3, 4.

[0029] However, both methods require a certain amount of time until the chip of the audio output stage 16 is powered on or off. During this period, it is not possible to play back audio content. The response times for the audio output stage 16 or the amplifier modules 5, 6 for startup, for example from 50 ms to 500 ms, are so long that the resulting dead time may be perceived as an interference by the vehicle user. If the speakers 7, 8 are also used to emit indication and / or warning tones, shorter response times are legally required. Therefore, it does not make sense to rely solely on the analysis of the presence of audio data for the speaker channels 7, 8 to deactivate the audio output stage 16 or the amplifier modules 5, 6 as a control variable for activation and deactivation.

[0030] To minimize the power loss of the audio system 1 and thus the energy consumption of the vehicle, if all audio sources 10.1 to 10.n assigned to at least one speaker channel 3, 4 of the digital audio output stage 16 are inactive, then the at least one speaker channel 3, 4 is deactivated by means of a logic-based controller 9.1 implemented in the control unit 9. In this case, the control unit 9 monitors the activity states A1 to An of the audio sources 10.1 to 10.n. In addition, when enabling and disabling the speaker channels 3, 4, the driving state parameter F of the vehicle and the operating parameter B of the vehicle and / or vehicle system can be taken into account.

[0031] The logic-based controller 9.1 is implemented, for example, as a software module in the control unit 9 and includes, for example, a so-called communication middleware for Ethernet communication in the vehicle and is configured for, for example, serialization and message exchange. Thus, the logic-based controller 9.1 decides, based on various input parameters, which speaker channels 3, 5 can be enabled or disabled. For example, based on the activity states A1 to An, it is checked whether the radio function is usually active or the permanent sound synthesis is active. For example, based on the driving state parameter F, it is checked how high the driving speed of the vehicle is, and based on this speed, it can be determined which information or warning tones must be played by the speakers 7, 8. For example, it can be provided that at a driving speed above 30 km / h, no Acoustic Vehicle Alert System (AVAS) is active, and / or at a driving speed below 20 km / h, all speakers 7, 8 inside the vehicle must always be active because, for example, the sound of the parking assist device has to be output. For example, the operating parameter B of the vehicle and / or vehicle system can be used to check whether a special energy-saving mode has been enabled.

[0032] Based on the activity states A1 to An and optionally the driving state parameter F and the operating parameter B, the control unit 9 forms an output signal S, by means of which, in the case of being deactivated by the mute devices 14, 15, the corresponding speaker channels 3, 4 are initially muted and only then the corresponding amplifier modules 5, 6 are deactivated. Thus, audible interference noises, especially crackling sounds, that may occur due to the deactivation of the corresponding amplifier modules 5, 6 can be avoided.

[0033] In addition, the output signal S can also affect the audio processing software implemented in the distribution module 2, such that the audio processing software is, for example, instructed not to integrate certain speaker channels 3, 4 into the audio reproduction or to set an emergency channel mix. Thus, interference effects that the user may experience during switching or in case of a fault can be avoided.

[0034] By individually controlling each of the loudspeaker channels 3, 4, it is possible to ensure that the loudspeaker channels 3, 4 required for the operating state remain active, and all other loudspeaker channels 3, 4 can be considered for an energy-saving state. In addition, the audio signals of the active audio sources 10.1 to 10.n can be bundled on at least one loudspeaker channel 3, 4, so that the other loudspeaker channels 3, 4 can be deactivated to save energy.

[0035] For example, a software module for implementing the logic-based controller 9.1 implemented in the control unit 9 can be integrated by means of freely programmable middleware. Therefore, the deactivation algorithm and related parameters (e.g., deactivation speed) for the loudspeaker channels 3, 4 can be flexibly adapted to the vehicle development process or transmitted to the vehicle via over-the-air updates. At the same time, in this way, it is possible to achieve the coordination of the deactivation possibilities of the loudspeaker channels 3, 4 with the range of audio sources 10.1 to 10.n included in the vehicle, the attributes of this audio source, the number of loudspeaker channels, the type of audio output stage 16, and the increasing experience and / or development progress.

[0036] It is also possible to use more than one software module to deactivate the loudspeaker channels 3, 4. For example, a software module for controlling the loudspeaker channels 3, 4 of the loudspeakers 7, 8 arranged inside the vehicle can be provided, and another software module for the loudspeakers 7, 8 arranged outside the vehicle and used for emitting external noise. Since the software for external noise must be certified, at a certain point in time, the software module of the external loudspeakers 7, 8 may no longer be modified. As a result of the separation of the software modules for deactivating the internal and external loudspeaker channels 3, 4, flexibility is maintained in the development process of the internal loudspeaker channels 3, 4 despite the so-called certification freeze of the external loudspeaker channels 3, 4.

[0037] The following table shows, for example, the loudspeakers 7, 8 or the loudspeaker channels 3, 4 for specific audio sources 10.1 to 10.n in a vehicle.

[0038]

[0039]

[0040] Table 1

Claims

1. A method for operating an audio system (1), the audio system having a plurality of audio sources (10.1 to 10.n) and a plurality of speaker channels (3, 4) for a plurality of speakers (7, 8) of a vehicle, It is characterized in that, by means of a logic-based controller (9.1) - monitoring the active states (A1 to An) of the audio sources (10.1 to 10.n), and - deactivating at least one of the speaker channels (3, 4) if all of the audio sources (10.1 to 10.n) assigned to the at least one speaker channel belonging to a digital audio output stage (16) are inactive.

2. The method according to claim 1, It is characterized in that the audio signals of the active audio sources (10.1 to 10.n) being bundled on at least one speaker channel (3, 4).

3. The method according to claim 1 or 2, It is characterized in that when monitoring the active states (A1 to An) of the audio sources (10.1 to 10.n), will take into account - driving state parameters (F) of the vehicle and / or - operating parameters (B) of the vehicle and / or - operating parameters (B) of vehicle systems.

4. The method according to any one of the preceding claims, It is characterized in that when a speaker channel (3, 4) is deactivated, the speaker channel (3, 4) is first muted and then the amplifier modules (5, 6) located in the speaker channel (3, 4) are deactivated.

5. The method according to any one of the preceding claims, It is characterized in that in the enabled state, the audio signals output by the coupled audio sources (10.1 to 10.n) are amplified by the amplifier modules (5, 6) located in the speaker channels (3, 4).

6. The method according to claim 5, Characterized in that, for each enabled speaker channel (3, 4), the received digital audio signal is converted into an analog audio signal by pulse width modulation before being forwarded to the corresponding speaker (7, 8).

7. The method according to any one of claims 4 to 6, It is characterized in that the muting of the speaker channel (3, 4) is performed by deactivating the pulse width modulation.

8. An audio system (1) for a vehicle, the audio system having - a plurality of audio sources (10.1 to 10.n) and - at least one digital audio output stage (16) coupled to the audio source (10.1 to 10.n), the digital audio output stage having a plurality of speaker channels (3, 4) for a plurality of speakers (7, 8), wherein, the speaker channels (3, 4) respectively amplify the audio signals output by at least one audio source (10.1 to 10.n) and transmit the amplified audio signals to at least one coupled speaker (7, 8), characterized in that at least one control unit (9) having a logic-based controller (9.1) is provided, wherein the control unit (9) is configured to - monitor the active states (A1 to An) of the audio sources (10.1 to 10.n), and - deactivate at least one of the speaker channels (3, 4) if all of the audio sources (10.1 to 10.n) assigned to the at least one speaker channel belonging to the plurality of speaker channels (3, 4) are inactive.

9. The audio system (1) according to claim 8, It is characterized in that, The control unit (9) is configured to bundle the audio signals of the active audio sources (10.1 to 10.n) onto at least one loudspeaker channel (3, 4).

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