DE102020211746A1 - Method for adjusting a power dissipation of an audio amplifier - Google Patents

Abstract

In order to create a method (10) for adapting a power loss of a control device (20), in particular an audio amplifier in a vehicle (100), which has a minimal influence on the user experience of vehicle occupants, at least one is proposed when a first temperature threshold is exceeded Measure to reduce the power loss of the control unit (20) in the form of a focus adjustment of a spatial sound (63) of the output signals (40), a frequency-dependent adjustment (62) of the output signals (40) and/or in the form of a blocking of audio signals (40) of at least a signal source (31, 32, 33).

Description

The invention relates to a method for adapting a power loss of a control device, in particular an audio amplifier, in a vehicle. Furthermore, the invention relates to a control device for carrying out the method.

State of the art

Infotainment functions are becoming increasingly important in vehicles. High demands are placed on the control units responsible for infotainment. In particular, the infotainment functions must also be available at extreme ambient temperatures, such as higher than 70°C and lower than -20°C. Especially at high ambient temperatures, the components of control units can heat up and be damaged due to power loss. Methods are already known for avoiding permanent damage caused by overheating, which deactivate the corresponding control units above a temperature threshold or prevent activation.

Control units in the form of audio amplifiers are also used to operate infotainment functions. These control units are responsible for activating the vehicle's loudspeakers and acoustically reproduce music, navigation instructions and warning tones. Mechanisms are also known for reducing power dissipation in audio amplifiers to limit internal temperature rise. For example, in the JP2001521709 a method is described which, depending on the temperature, continuously reduces the output volume of the audio signals. As a result, the volume of the audio signals is provided with the same damping factor over the entire frequency band in order to obtain the volume-reduced output signal.

However, measures to reduce power dissipation by reducing or limiting the volume of the loudspeakers have an adverse effect on the user experience of vehicle occupants.

Disclosure of Invention

The invention is based on the object of creating a method for reducing the power loss which has a minimal impact on the user experience of vehicle occupants.

This object is achieved by the features specified in claim 1 and claim 10. Further advantageous configurations of the invention are described in the dependent claims.

According to one aspect of the invention, a method for adjusting a power loss of a control device, in particular an audio amplifier in a vehicle, is provided.

In one step, the control unit receives audio signals from at least one signal source and outputs them to at least one loudspeaker in the form of output signals.

Measurement data collected by a temperature sensor is also received. The temperature of one or more components of the control unit is monitored by evaluating measurement data from the temperature sensor. Alternatively or additionally, multiple temperature sensors can be used to enable more precise temperature monitoring. Temperature monitoring can be implemented by the control unit itself or by an independent protective circuit.

If a first temperature threshold is exceeded, at least one measure to reduce the power loss of the control unit is carried out.

According to the invention, the at least one measure for reducing the power loss is carried out in the form of a centroid adjustment of a spatial sound of the output signals, a frequency-dependent adjustment of the output signals and/or in the form of a blocking of audio signals from at least one signal source.

According to a further aspect of the invention, a control device is provided. The control device can preferably be designed as an audio amplifier or have an audio amplifier. The control unit is set up to regulate the temperature of the audio amplifier and in particular the method according to the invention.

With the method, the assistance systems and sensors used in vehicles can be used to maximize the user experience of vehicle occupants under given temperature boundary conditions. The measures to reduce the power loss can be used one after the other, in combination or individually in order to undertake a subtle adjustment of the power loss of the control unit that is not noticeable to the vehicle occupants.

The power loss can include all components of the control unit or relate to specific components. For example, in a control unit with an integrated audio amplifier, the adjustment of the power loss on the power loss and the resulting heating of the audio amplifier.

The control unit can use the measurement data from the at least one temperature sensor to limit the power loss of various audio components and in particular of the audio amplifier. Based on the provided temperature signal or the measurement data, the control unit can decide whether, and if so, which measure to reduce the temperature and the power loss is to be taken.

The control unit can preferably decide whether to implement a focus of the spatial sound, a frequency-dependent adjustment or a complete or partial blocking of audio signals. As a result, interventions in the output of audio signals can be implemented, which have different influences on the user experience of vehicle occupants. Measures such as the adjustment of the center of gravity in the vehicle interior or the frequency-dependent adjustment of the audio signals can preferably be carried out in a way that the vehicle occupants do not notice.

In one embodiment, in the measure to reduce the power loss in the form of frequency-dependent adjustment of the output signals, at least one frequency range of the output signals is damped to reduce the power loss of the control unit.

The power loss of the amplifier or audio amplifier depends on the frequency of the audio signal. As a loudspeaker for low frequencies requires a greater displacement of the membrane and thus of the coil, more power is also required for this. The power loss of the audio amplifier is still proportional to the power output. Depending on the design of the audio amplifier, the efficiency can usually be between 50 and 90%. In order to reduce the power loss in the audio amplifier and to achieve a frequency-dependent adaptation of the audio signals, low frequencies can be attenuated more than high ones by a filter. With such an "equalizer" setting, bass in the music or in the audio signals can be reduced compared to treble.

For example, a frequency range of 300 - 600 Hz, in which melodies and singing lie, remain unchanged in order to enable a natural sound despite the frequency-dependent adjustment of the audio signals.

The energy savings resulting from this measure depend on the frequency spectrum of the audio signals. If these have high bass components, a particularly high energy saving can be achieved.

The frequency-dependent adjustment of the audio signals can be individually and particularly precisely tailored to a driver if measurement data is received from at least one sensor of a driver monitoring function to determine the driver's receptivity, the at least one frequency range of the output signals to be damped depending on the measurement data received from the sensor Driver monitoring function is set. Age, state of fatigue and the like can be determined based on the measurement data of the at least one sensor. This information can provide insight into the driver and his or her receptivity. In particular, tired or elderly drivers or vehicle occupants can have impaired hearing, as a result of which certain frequencies of the audio signal are not perceived. Certain frequencies and volumes can thus be dampened or adjusted without restricting the vehicle occupants.

In particular, in addition to the signal sources and output channels or loudspeakers, any vehicle-side sensors such as interior cameras, seat occupancy sensors, sensors for detecting tiredness and the like can also be connected to the control unit in a data-conducting manner.

According to a further embodiment, one or more loudspeakers for outputting the audio signals are deactivated depending on seat occupancy in the measure for reducing the power loss in the form of center of gravity adjustment of the spatial sound of the output signals, in particular in a passenger compartment of the vehicle. The focal point of the spatial sound can be shifted by this measure.

To reduce the output power of the control unit or the audio amplifier, the volume of individual loudspeakers can be reduced individually. The aim is to influence the sound experience of the vehicle occupants as little as possible. Since the speakers in the rear of a vehicle are primarily designed to improve the sound of the rear passengers, the speakers responsible for this can be deactivated when one or two vehicle occupants are present.

According to a further exemplary embodiment, activated loudspeakers are operated with an adapted volume distribution and/or direction of emission during the focus adjustment of the spatial sound of the output signals. By a By detecting the number and seating position of vehicle occupants, fading or balancing of the focus of the audio playback can be set to specific zones in the vehicle without the vehicle occupants noticing this change.

For this purpose, it is determined via the seat occupancy signals, such as from belt tensioners, weight detection, camera detection, and the like, which seats in the vehicle are occupied. The loudspeakers are then individually amplified or controlled by the control unit in such a way that the sound for passengers hardly changes, while a significant volume reduction can be measured in an unoccupied area. For example, if the rear is unoccupied, the volume of the rear speakers can be significantly reduced.

As an alternative or in addition to electronic control, the direction of emission can be adjusted by mechanically twisting the loudspeakers. By twisting at least one loudspeaker, the propagation direction of the sound can be changed. Thus, the sound can be sent more directed to the specific person or place in the vehicle. With this measure, the intensity and thus power loss of the sound system can be reduced with the same audible volume.

A level and a frequency spectrum of the output audio signals can be adapted to ambient noise in the passenger compartment or vehicle interior if measurement data is received from at least one microphone and an output power of the output signals is adapted depending on the measurement data received from the microphone. In this way, the volume of the loudspeakers can be set lower if the volume of background noise is low. With a higher level of extraneous noise, the volume of the audio signals can be increased.

Furthermore, one or more microphones can be used to receive feedback on the output of the audio signals that can actually be heard in the vehicle interior. As a result, a reaction or regulation of the output audio signals can take place, as a result of which, for example, certain frequencies in the vehicle interior are reproduced in an amplified or weakened manner. Such a procedure can also be carried out as a measure to reduce the power loss.

According to a further exemplary embodiment, to block audio signals from the at least one signal source, audio signals are assigned to the at least one signal source and the audio signals are filtered in a way that is adapted to the signal source to be blocked. For this purpose, the signal source or the audio signals received from the signal source can be classified in one step and subjected to filtering in a second step. In this way, one or more signal sources can be excluded from playback through the loudspeakers.

Basically, filtering out individual signal sources with the same amplification of the remaining signal sources leads to a reduced power loss. Filtering or switching off a signal source has a correspondingly higher impact on the user experience of the vehicle occupants. In particular, such an intervention should only be used in the unavoidable case in order to protect the control unit from damage from overheating. Different signal sources can influence the power loss differently. Safety-relevant signal sources, such as tones from turn signals, tones from parking sensors, traffic reports, warning messages and the like, can preferably be excluded from the measures.

The power loss of the control unit can be set particularly precisely if at least one measure to reduce the power loss is carried out when the measurement data received from the temperature sensor exceeds the first temperature threshold, a second temperature threshold and a third temperature threshold, with the second temperature threshold being higher than the first temperature threshold and the third temperature threshold are designed to be higher than the second temperature threshold.

If a first temperature threshold is exceeded, the center of gravity of the spatial sound can be shifted, for example. Depending on the seat occupancy, this measure can prevent the temperature of the control unit from rising further. If the second, higher, temperature threshold is exceeded, the audio signal can be adjusted as a function of frequency. The infotainment audio source can only be deactivated after the third temperature threshold has been exceeded.

The order in which the measures are triggered is selected by the control device in such a way that the user experience is influenced as little as possible.

According to a further embodiment, if the measurement data received from the temperature sensor is exceeded, the third temperature threshold performed the blocking of audio signals from at least one signal source. This measure can, as a last resort, disable the control unit or just the audio amplifier to prevent a further increase in temperature. This can prevent damage to the control unit.

• 1 ein schematisches Ablaufdiagramm zum Veranschaulichen eines erfindungsgemäßen Verfahrens gemäß einer Ausführungsform,
• 2 ein schematisches Frequenzspektrum zum Veranschaulichen einer frequenzabhängigen Anpassung von Audiosignalen,
• 3 eine schematische Draufsicht auf einen Fahrzeuginnenraum zum Veranschaulichen einer Schwerpunktsanpassung eines Raumklangs, und
• 4 eine schematische Draufsicht auf den Fahrzeuginnenraum zum Veranschaulichen der Schwerpunktsanpassung eines Raumklangs durch eine mechanische Drehung von Lautsprechern.

Several exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Show it:

• 1 a schematic flowchart to illustrate a method according to the invention according to one embodiment,
• 2 a schematic frequency spectrum to illustrate a frequency-dependent adaptation of audio signals,
• 3 a schematic plan view of a vehicle interior to illustrate a center of gravity adjustment of a spatial sound, and
• 4 a schematic plan view of the vehicle interior to illustrate the center of gravity adjustment of a spatial sound by a mechanical rotation of speakers.

In the 1 a schematic flow chart is shown to illustrate a method 10 according to an embodiment of the invention. Method 10 is used to adapt a power loss of a control unit 20. Control unit 20 can preferably have an integrated audio amplifier which receives audio signals 30 from at least one signal source 31, 32, 33 and converts them into output signals 40 for playback through loudspeakers 41, 42, 43, 44 can reinforce.

The signal sources can be, for example, safety-related signal sources 31, such as warning messages or traffic reports, entertainment functions 32 or vehicle-side signal sources 33, such as flashing lights.

Furthermore, control unit 20 can receive and evaluate measurement data from at least one temperature sensor 50 . As further options, sensors 51 from the driver monitoring function, seat occupancy sensors 52 and microphones 53 can be connected to control unit 20 in a data-conducting manner.

The received audio signals 30 can be assigned to a signal source 31 , 32 , 33 by a classifier 60 and then filtered or blocked in a filter 61 . As a result, a measure to reduce the power loss of control unit 20 can be implemented in the form of blocking audio signals.

Furthermore, measurement data from the microphone 53 can be used to implement a frequency-dependent adaptation 62 of the output signals 40 as a further measure for reducing the power loss of the control unit 20 . The measurement data from the microphone 53 can also be used to adjust the center of gravity of a spatial sound 63 .

In the measure to reduce the power loss in the form of a center of gravity adjustment of a spatial sound 63 of the output signals 40, the measurement data of the sensors 51 of the driver monitoring function and the seat occupancy sensors 52 can preferably be used.

the 2 shows a schematic frequency spectrum to illustrate a frequency-dependent adaptation 62 of audio signals 40.

The frequency response diagram or the diagram shows which amplification characteristic is applied to the audio signal 40 . In the normal state 45 of the frequency spectrum, all relevant areas of the frequency band are equally amplified. Very high or low frequencies that are hardly perceived by humans and cannot be represented by the loudspeakers 41, 42, 43, 44 are filtered.

In the case of the selectively reduced volume 46, frequency ranges which result in a high energy consumption of the control unit 20, such as low frequencies, are attenuated to a greater extent. The characteristics of the characteristic curve are set in such a way that the sound does not change too much for the listener to perceive. In particular, in a frequency range of 300 - 600 Hz, in which melodies and singing lie, the frequency characteristics can remain as unchanged as possible in order to obtain a natural sound.

In the 3 a schematic top view of a vehicle interior 110 of a vehicle 100 is shown to illustrate a center of gravity adjustment 63 of a spatial sound. Four loudspeakers 41, 42, 43, 44 are arranged in the vehicle interior 110, two loudspeakers 41, 42 being set up to provide acoustic functions for a driver and a passenger. Two additional loudspeakers 43, 44 are set up to act on a fund 120 of the vehicle 100.

The focal point S of the spatial sound is shown schematically. In this case, the focus S is shifted to S' by the measure of the focus adjustment 63 of the spatial sound. esp In particular, the sound can concentrate in the driver's area, with the rear 120 of the vehicle 100 being subjected to deactivated or reduced power of the output signals 40 .

Free seats 130 and occupied seats 131 are shown schematically in the exemplary embodiment. By reducing the power of the output signals 40 of the loudspeakers 43, 44 in the rear 120, the center of gravity S of the surround sound can be shifted forward.

In the 4 1 is a schematic plan view of the vehicle interior 110 illustrating centroid adjustment 63 of surround sound through mechanical rotation of speakers 47 . In this case, one or more rotatably arranged loudspeakers 47 are provided, through which a direction of emission of the sound can be controlled. The remaining loudspeakers 44 can be activated or deactivated by the controller 20 .

The rotatable or pivotable loudspeakers 47 allow a direct focus adjustment 63 of the spatial sound. A precise control of the center of gravity S′ can also be implemented when the seat 131 is occupied, with the required power and thus also the power loss of the control device 20 being reduced by at least one deactivated loudspeaker 44 .

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP 2001521709 [0003]

Claims (10)

Method (10) for adapting a power loss of a control unit (20), in particular an audio amplifier in a vehicle (100), wherein - audio signals (30) of at least one signal source (31, 32, 33) are received by the control unit (20) and in the form output signals (40) are sent to at least one loudspeaker (41, 42, 43, 44), - measurement data collected by a temperature sensor (50) are received, - if a first temperature threshold is exceeded, at least one measure to reduce the power loss of the control unit ( 20) is carried out, characterized in that the at least one measure for reducing the power loss is in the form of a focal point adjustment of a spatial sound (63) of the output signals (40), a frequency-dependent adjustment (62) of the output signals (40) and/or in the form of blocking of audio signals (40) from at least one signal source (31, 32, 33). procedure after claim 1 , wherein at least one frequency range of the output signals (40) to reduce the power loss of the control unit (20) is damped in the measure to reduce the power loss in the form of frequency-dependent adjustment (62) of the output signals (40). procedure after claim 2 , measurement data from at least one sensor (51) of a driver monitoring function being received in order to determine a driver's receptivity, the at least one frequency range of the output signals (40) to be damped being set as a function of the received measurement data from the sensor (51) of the driver monitoring function. Procedure according to one of Claims 1 until 3 , wherein in the measure to reduce the power loss in the form of center of gravity adjustment (63) of the surround sound of the output signals (40), in particular in a vehicle interior (110) of the vehicle (100), one or more loudspeakers (41, 42, 43, 44) for outputting the output signals (40) are deactivated depending on a seat occupancy. procedure after claim 4 , wherein activated loudspeakers (41, 42, 43, 44) with an adjusted volume distribution and/or loudspeakers (47) with an adjustable emission direction are operated during the focus adjustment of the spatial sound (63) of the output signals (40). Procedure according to one of Claims 1 until 5 , wherein measurement data is received from at least one microphone (53) and an output power of the output signals (40) is adjusted depending on the measurement data received from the microphone (53). Procedure according to one of Claims 1 until 6 , wherein for the blocking of audio signals (30) from the at least one signal source (31, 32, 33) an assignment of received audio signals (30) to the at least one signal source (31, 32, 33) and to a signal source (31 , 32, 33) adapted filtering (61) of the received audio signals (30) are carried out. Procedure according to one of Claims 1 until 7 , wherein in each case at least one measure to reduce the power loss is carried out when the measurement data received from the temperature sensor (50) exceeds the first temperature threshold, a second temperature threshold and a third temperature threshold, the second temperature threshold being higher than the first temperature threshold and the third temperature threshold being higher than the second temperature threshold are configured. procedure after claim 8 , wherein when the measurement data received from the temperature sensor (50) exceeds the third temperature threshold, the blocking of audio signals (30) from at least one signal source (31, 32, 33) is performed. Control unit (20), in particular for controlling the temperature of an audio amplifier, the control unit (20) being set up to carry out the method (10) according to one of Claims 1 until 9 to execute.

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