Method for operating a vehicle audio system and audio system

Abstract

A novel method of operating a vehicle audio system and a novel vehicle audio system are provided. The present invention relates to a method for operating a vehicle audio system (1), in which a logic-based control unit (9.1) monitors the activity states (A1-An) of audio sources (10.1-10.n) and deactivates at least one speaker channel (3, 4) of a digital audio output stage (16) if all audio sources (10.1-10.n) assigned to this speaker channel (3, 4) are inactive. The present invention also relates to a vehicle audio system (1).

Description

[Technical Field]

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

[0002] Furthermore, the invention relates to a vehicle audio system according to the preamble of claim 8. [Background technology]

[0003] Patent Document 1 below discloses a control device for an audio amplifier for reducing a disturbing influence on a reproduced audio signal. When a disturbing influence on the reproduced audio signal occurs, the control device attenuates the output of the audio amplifier to reduce the reproduction volume of the audio signal. When the disturbing influence on the reproduced audio signal disappears, the control device increases the output of the audio amplifier to the value that was set before attenuation.

[0004] Furthermore, Patent Document 2 below discloses a method and device for dynamically managing the dead time between switching on of transistors in an output power stage of an audio amplifier. In this case, a driver signal is generated based on an input signal, and the driver signal is amplified by alternately controlling a first transistor and a second transistor with a time interval between deactivating the first transistor and activating the second transistor. This time interval is set based on a parameter of the input signal or the driver signal being amplified. The parameter is the amplitude of the input signal, the duty cycle of the driver 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] From the patent application WO 02 / 049999, an audio system is known which is deactivated in order to save energy in the absence of an audio signal or in the case of a mute command.From the patent application WO 02 / 049999, an audio system is known in connection with a seat which switches between two modes depending on the occupancy of the seat. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE 198 15 923 A1 [Patent Document 2] US Patent Application Publication No. 2017 / 0250654 A1 [Patent Document 3] German Patent Application Publication No. 10 2021 003 593 A1 [Patent Document 4] U.S. Patent Application Publication No. 2019 / 0007777 A1 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem on which the invention is based is to provide a novel method for operating a vehicle audio system and a novel vehicle audio system. [Means for solving the problem]

[0008] According to the invention, this problem is solved by a method having the features of claim 1 and an audio system having the features of claim 8.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] In accordance with the present invention, a method for operating a vehicle audio system includes a logic-based control (control unit) that monitors the activity of audio sources and deactivates at least one speaker channel of a digital audio output stage if all audio sources assigned to that speaker channel are inactive.

[0011] In today's audio entertainment systems in vehicles, in addition to the acoustic output of traditional entertainment content, such as radio content, sound design and audio signals assigned to various vehicle functions, such as turn signal sounds, warning sounds, and parking assistance sounds, are also output. Due to the large number of speakers installed in or on a vehicle, the audio amplifiers of audio entertainment systems consume energy even when not all speaker channels are needed. This results from the fact that audio signals are generated in the audio output stage itself, for example using a so-called audio programming platform, and then transmitted to a further amplifier system or speakers for playback. The conversion modules used, particularly the digital-to-analog converters and the audio output stage, then incur power losses even when the audio output is not being used, i.e., when the signal content is zero. Completely switching off the audio output stage, including its power supply, offers significant savings potential, but this can only be achieved by deactivating all speaker channels.

[0012] In contrast, the present method allows for dynamic switching of speaker channels on and off during driving based on complex theoretical conditions based on the current system state in the vehicle, thereby achieving energy savings on unnecessary speaker channels. However, the activation and deactivation (enabling and disabling) of speaker channels takes time, which can disrupt the response behavior when playing audio signals and lead to audible audio artifacts. By taking into account the activity of the audio source, particularly the signal content of the output audio signal, the present method enables predictive deactivation and activation of speaker channels, effectively avoiding audible audio artifacts and drowning out ("Verschlucken" von Tonen) during activation. Therefore, from the user's perspective, the functionality of the audio system is not impaired. As a result, energy consumption during actual vehicle operation can be reduced without imposing restrictions on the vehicle user. In particular, the present method can be implemented using flexibly adaptable software. This means that software components can be programmed by vehicle manufacturers within the sound function, increasing the safety of eliminating audio artifacts. This also allows for easy variability in handling speaker channel deactivation between different models of vehicles or even different audio systems.

[0013] In a possible embodiment of the method, the audio signals of the active audio sources are combined into at least one speaker channel, such that, for example, an audio signal being processed on a less used speaker channel can be transmitted to another speaker channel, thereby deactivating the less used speaker channel.

[0014] In a further possible embodiment of the present invention, the vehicle driving state and / or vehicle operating parameters and / or vehicle system operating parameters are taken into account when monitoring the activity of the audio sources. This makes it possible to determine which audio signals or audio content need to be reproduced, so that in a particularly advantageous manner, only speaker channels that are deemed unlikely to be used in the currently detected situation are deactivated. For example, in vehicle driving states where the vehicle speed is above 30 km / h, the output of parking assistance tones is not necessary, so speaker channels that output these tones can be deactivated if other audio sources using these speaker channels are also inactive.

[0015] In a further possible embodiment of the method, when deactivating a speaker channel, the speaker channel is first switched to mute and then the amplifier module located in the speaker channel is deactivated, which makes it possible to avoid audible disturbances such as pops or clicks when deactivating the corresponding speaker channel.

[0016] In a further possible embodiment of the method, the audio signals actively output by the connected audio sources are amplified using amplifier modules located in the speaker channels, which allows the audio signals of each speaker channel to be amplified separately.

[0017] In a further possible embodiment of the method, for each active speaker channel, the received digital audio signal is converted into an analog audio signal by pulse width modulation before being played on the corresponding speaker, which allows for processing of the digital audio signal and output of the analog audio signal.

[0018] In a further possible embodiment of the method, the muting of the speaker channel is performed by pulse width modulation deactivation, which makes the deactivation easy to perform and reliable.

[0019] The vehicle audio system includes a plurality of audio sources and at least one digital audio output stage connected to the audio sources and having a plurality of speaker channels, each of which amplifies an audio signal output by at least one audio source and transmits the amplified audio signal to at least one connected speaker.

[0020] According to the present invention, at least one control unit having a logic-based control section is provided, wherein the control unit is configured to monitor the activity status of the audio sources and to deactivate at least one speaker channel if all audio sources assigned to that speaker channel are inactive.

[0021] This audio system allows speaker channels to be dynamically switched on and off during driving based on complex logic conditions based on the current system state in the vehicle, thereby achieving energy savings on unnecessary speaker channels. However, activating and deactivating speaker channels takes time, which can disrupt the response behavior when playing audio signals and lead to audible audio artifacts. However, this audio system enables predictive activation and deactivation of speaker channels by taking into account the activity of the audio source, particularly by additionally considering the signal content of the output audio signal, thereby effectively avoiding audible audio artifacts and sound "drowning" during activation. Therefore, from the user's perspective, the functionality of the audio system is not impaired. As a result, energy consumption during actual vehicle operation can be reduced without restricting the vehicle user. In particular, the speaker channel deactivation function can be implemented using flexibly adaptable software. This means that the software component can be programmed by the vehicle manufacturer within the sound function, increasing the safety of eliminating audio artifacts. This also allows for easy variability in handling speaker channel deactivation between different models of vehicles or even different audio systems.

[0022] Furthermore, in a possible embodiment of the audio system, the control unit is configured to aggregate audio signals of active audio sources into at least one speaker channel, such that, for example, an audio signal being processed on a less used speaker channel can be transmitted to another speaker channel, thereby deactivating the less used speaker channel.

[0023] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic block diagram of a vehicle audio system. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the sole FIG. 1, a block diagram of a vehicle audio system 1 is shown. The audio system 1 comprises 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. Furthermore, the audio system 1 comprises a data source 11 for vehicle driving state parameters F, a data source 12 for special operating parameters B of the vehicle and / or vehicle systems, and a data source 13 for transmitting activity states A1 to An of the audio sources 10.1 to 10.n to the control unit 9. A muting device 14, 15 is arranged in each of the speaker channels 3, 4.

[0026] In the audio system 1, audio processing software implemented in a distribution module 2 distributes the audio content output and played from the audio sources 10.1 to 10.n to the different speaker channels 3, 4 present in the vehicle. In embodiments not shown in detail, any number of speaker channels 3, 4 and speakers 7, 8 is possible, in addition to the two speaker channels 3, 4 shown for the purpose of illustrating the audio system 1. The audio content is converted into an electrical signal and amplified so that the speakers 7, 8 can emit a corresponding sound. This amplification is performed in amplifier modules 5, 6, which generate an output loss even when no audio signal is present to amplify. However, if the amplifier modules 5, 6 are deactivated, no output loss occurs.

[0027] The activation and deactivation of the amplifier modules 5, 6 can be achieved in various ways, allowing different energy saving possibilities depending on the method. All audio output stages 16 can be activated or deactivated, or, as is the case with digital audio output stage 16, pulse width modulation, which converts digital audio signals output from audio sources 10.1 to 10.n into analog audio signals before playback on the corresponding speakers 7, 8, can be activated or deactivated. While the activation and deactivation of all audio output stages 16 often relates to multiple speaker channels 3, 4, the activation and deactivation of pulse width modulation in digital audio output stage 16 allows for individual activation and deactivation of each speaker channel 3, 4.

[0028] However, both methods require a certain amount of time for the audio output stage 16 chip to power up or shut down. During this time, audio content cannot be played. The response time for the audio output stage 16 or the amplifier modules 5, 6 to start up is long, e.g., 50 ms to 500 ms, and the resulting dead time can be annoying to vehicle users. When the speakers 7, 8 are used to output caution and / or warning sounds, shorter response times are required by law. Therefore, it is not convenient to deactivate the audio output stage 16 or the amplifier modules 5, 6 solely by analyzing whether audio data is present for the speaker channels 3, 4 as a control variable for activation and deactivation.

[0029] In order to minimize power losses and thus energy consumption of the audio system 1 and the resulting energy consumption of the vehicle, a logic-based control 9.1 implemented in the control unit 9 deactivates at least one speaker channel 3, 4 of the digital audio output stage 16 if all audio sources 10.1 to 10.n assigned to this speaker channel 3, 4 are inactive. The control unit 9 then monitors the activity states A1 to An of the audio sources 10.1 to 10.n. Furthermore, a vehicle driving state parameter F and an operating parameter B of the vehicle and / or vehicle system can be taken into account when activating and deactivating the speaker channels 3, 4.

[0030] The logic-based control unit 9.1 is implemented in the control unit 9, for example as a software module, and includes a so-called communication middleware, e.g., for Ethernet communication within the vehicle, configured for serialization and message exchange. The logic-based control unit 9.1 thus determines which speaker channels 3, 4 can be activated or deactivated depending on various input parameters. For example, the activity states A1-An are used to determine whether a wireless function is generally active or whether continuous sound synthesis is active. The driving state parameter F is used to determine, for example, the vehicle's driving speed and, accordingly, which information or warning sounds should be played on the speakers 7, 8. For example, it can be specified that an Acoustic Vehicle Alert System (AVAS) should not be activated at driving speeds above 30 km / h, and / or that all speakers 7, 8 in the vehicle cabin should be activated at driving speeds below 20 km / h, since, for example, parking assistance sounds are output. The operating parameters B of the vehicle and / or vehicle systems can be used to check, for example, whether a special energy saving mode is activated.

[0031] Depending on the activity states A1 to An and, if necessary, on the driving state parameter F and the operating parameter B, the control unit 9 generates an output signal S, by means of which, in the case of deactivation, the corresponding loudspeaker channel 3, 4 is first muted by the muting device 14, 15 and then the respective amplifier module 5, 6 is deactivated. This makes it possible to avoid audible disturbances, in particular popping sounds, which may be caused by the deactivation of the respective amplifier module 5, 6.

[0032] Furthermore, the output signal S can also influence the audio processing software implemented in the distribution module 2, for example to instruct this software not to include certain speaker channels 3, 4 in the audio playback or to set an emergency channel mix, thereby avoiding disruptive effects experienced by users when switching or in the event of a fault.

[0033] The individual control of the individual speaker channels 3,4 allows the speaker channels 3,4 required for the operating state to remain active while all other speaker channels 3,4 are taken into account for energy saving states. It is also possible to combine the audio signals of the active audio sources 10.1 to 10.n into at least one speaker channel 3,4, thereby deactivating the other speaker channels 3,4 to save energy.

[0034] For example, the software modules implemented in the control unit 9 for realizing the logic-based control 9.1 can be integrated by freely programmable middleware. This allows the deactivation algorithms for the speaker channels 3, 4 and related parameters, such as the deactivation speed, to be flexibly adapted to the vehicle development process and transmitted to the vehicle via over-the-air updates. At the same time, the range of deactivation options for the speaker channels 3, 4 can be adapted to the audio sources 10.1 to 10.n included in the vehicle, their characteristics, the number of speaker channels, the type of audio output stage 16, the increasing experience and / or development progress.

[0035] It is also possible to use multiple software modules for deactivating the speaker channels 3, 4. For example, there may be a software module for controlling the speaker channels 3, 4 of the speakers 7, 8 located inside the vehicle and another software module for the speakers 7, 8 located outside the vehicle for outputting exterior noise. Since the software for exterior noise is subject to mandatory certification, the software module for the exterior speakers 7, 8 cannot be changed at a certain point. As explained, by separating the software modules for deactivating the interior and exterior speaker channels 3, 4, flexibility in the development process for the interior speaker channels 3, 4 is maintained despite the so-called certification freeze for the exterior speaker channels 3, 4.

[0036] The table below shows which speaker 7, 8 or speaker channel 3, 4 is used for a particular audio source 10.1 to 10.n in the vehicle. [Table 1]

Claims

1. A method for operating an audio system (1) having a plurality of audio sources (10.1 to 10.n) and a plurality of speaker channels (3, 4) of a plurality of vehicle speakers (7, 8), comprising: By logic-based control (9.1), The activity states (A1-An) of the audio sources (10.1-10.n) are monitored; At least one of the plurality of speaker channels (3, 4) of the digital audio output stage (16) is deactivated if all audio sources (10.1 to 10.n) assigned to this speaker channel (3, 4) are inactive. A method characterized by:

2. The audio signals of the active audio sources (10.1 to 10.n) are summed into at least one speaker channel (3, 4).

2. The method of claim 1 .

3. When monitoring the activity states (A1 to An) of the audio sources (10.1 to 10.n), a running state parameter (F) of the vehicle; and / or (B) operating parameters of the vehicle; and / or Vehicle system operating parameters (B) is taken into consideration 3. The method according to claim 1 or claim 2.

4. When the speaker channels (3, 4) are deactivated, the speaker channels (3, 4) are first switched to mute, and then the amplifier modules (5, 6) in the speaker channels (3, 4) are deactivated. The method according to any one of claims 1 to 3.

5. The audio signals outputted in an active state by the connected audio sources (10.1 to 10.n) are amplified using amplifier modules (5, 6) in the speaker channels (3, 4). The method according to any one of claims 1 to 4.

6. For each active speaker channel (3, 4), the received digital audio signal is converted to an analog audio signal by pulse width modulation before being played on the corresponding speaker (7, 8).

6. The method of claim 5.

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

8. 1. A vehicle audio system (1) comprising a plurality of audio sources (10.1 to 10.n) and at least one digital audio output stage (16) connected to the audio sources (10.1 to 10.n) and having a plurality of speaker channels (3, 4) for a plurality of speakers (7, 8), wherein each of the speaker channels (3, 4) amplifies an audio signal output by at least one audio source (10.1 to 10.n) and transmits the amplified audio signal to at least one connected speaker (7, 8), At least one control unit (9) is provided having a logic-based control (9.1), The control unit (9) monitoring the activity status (A1-An) of said audio sources (10.1-10.n); deactivating at least one of said plurality of speaker channels (3, 4) when all audio sources (10.1 to 10.n) assigned to said speaker channel (3, 4) are inactive; It is configured as follows: An audio system (1).

9. The control unit (9) is configured to combine the audio signals of the active audio sources (10.1 to 10.n) into at least one speaker channel (3, 4). Audio system (1) according to claim 8.

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