GB2430817A

GB2430817A - Audio system for a motor vehicle

Info

Publication number: GB2430817A
Application number: GB0520048A
Authority: GB
Inventors: Chris Pedlar
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2005-10-03
Filing date: 2005-10-03
Publication date: 2007-04-04
Anticipated expiration: 2025-10-03
Also published as: GB0520048D0; GB2430817B

Abstract

An audio system is described for a vehicle having seat occupancy sensors. The system includes adjustable digital signal processing and varies the settings of the signal processing in dependence upon the detected occupancy of the vehicle. Thus, for example, the system adjusts the left to right balance (stereo balance) of the speakers according to whether the driver is alone, or accompanied by passengers. The system may share seat sensors with an airbag deployment system.

Description

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AUDIO SYSTEM FOR A MOTOR VEHICLE

The present invention relates to an audio system for a motor vehicle.

Premium audio systems used in motor vehicles typically feature digital signal processing (DSP) which allows the user to adjust the equalisation of the audio system to suit the type of music being played, for example rock, classical, voice etc. DSP settings also allow the acoustic output to be optimised such that the "staging" of a performance can be set to the best compromise for all occupants or optimised for the driver only when unaccompanied. Typically the default settings of the DSP provide the best compromise for multiple occupancy. As a result, when the driver is travelling alone, which is often the case, the settings are not at their optimum.

With a view to mitigating this disadvantage, the present invention provides an audio system for a motor vehicle having occupant sensors, wherein the audio system includes adjustable digital signal processing, means for receiving from the occupant sensors a signal indicative of the prevailing vehicle occupancy, and means for varying the settings of the digital signal processing in dependence upon the detected occupancy of the vehicle.

Modern vehicles often feature advanced restraint systems which are able to tailor the deployment of airbags in dependence upon the severity of the collision and the presence and weight of the occupants. For example, a sensor may be used to detect whether anyone is sitting in the passenger seat and to inhibit the deployment of the passenger airbag if no one is present.

The present invention can be implemented in such a vehicle without the need for additional hardware by using the information available from the existing occupant sensors of an airbag deployment system to vary the settings of digital signal processing of the audio system to optimise them for the detected prevailing occupancy of the vehicle.

In this way, when the driver is unaccompanied, the settings of the audio system would be optimised for the driver alone whereas when other passengers are detected to be present then the settings of the digital signal processing system would be optimised for multiple occupancy.

The invention allows an audio system to be programmed with many different optimised sets of settings of the digital signal processing to suit different seating configurations and the system can then switch between memorised sets of settings in dependence upon which seats are detected to be occupied. Within each set of settings, the digital signal processing may set any one or more of the relative amplitude of the sound emitted from different speakers in the vehicle, the relative phase of the sound emitted from different speakers and the filtering applied to sound emitted by the different speakers. It will be appreciated that the filtering can modify the relative amplitude of the different frequencies emitted by any one of the speakers as well as effect more complex manipulation of the audio output such as by adding echoes and reverberations.

The seat occupancy signal may in the simplest case merely indicate if a person is present in the vehicle in addition to the driver. This information could, for example, be used to set the left to right balance of the speakers.

However, the seat occupancy signal may additionally provide information on the distribution of the additional passengers in the vehicle, for example to allow the balance between the front and the rear speakers to be set more appropriately.

The invention will now be described further, by way of example, with reference to the accompanying drawing which is a block diagram of an audio system in accordance with the present invention.

The drawing shows an audio system installed in a vehicle having an airbag deployment system 10 receiving signals from seat occupant sensors 12. These two components are not part of the audio system as such but are part of the vehicle in which the audio system is installed.

Aside from the input received from the airbag deployment system 10 to provide an indication of the seat occupancy, the remaining blocks in the drawing represent a conventional audio system which need not be described in detail. The audio system essentially comprises an audio amplifier 14 with digital signal processing having manual controls 16 and receiving audio input from a tuner 18, a CD player 20 and a cassette player 22. The amplifier 14 drives four speakers namely front left and right speakers 26 and 28, and rear left and right speakers 30 and 32.

The manual controls 16 allow the user to set the digital signal processing within the audio amplifier 14 to achieve various effects. In particular, the relative volume of the sound emitted by the left and right speakers can be adjusted to affect the "staging" of the sound. For example, when the driver is alone in the vehicle, the volume of the sound emitted by the nearside speaker can be made greater than the volume of the offside speaker to compensate for its greater distance from the driver so that the centre of the stage from which the sound is performed appears to be directly in front of the driver. In a similar way, the relative volume of the front and rear speakers can be adjusted.

The driver is able to set the digital signal processing to suit his own preferences regarding the tone and filtering of the sound, as well as its staging, enabling him to emulate the acoustics of a rock concert, a church or a concert hall.

When the driver is accompanied by one or more passengers, however, the same settings of the digital signal processing may prove less than ideal. The present invention enables the presence of such additional passengers to be detected and to be used to switch the settings of the digital signal processing automatically to suit the prevailing occupancy of the vehicle.

In practice, the manual controls 16 are used in a programming mode to set the audio amplifier 14 to suit the prevailing occupancy of the vehicle. Once a set of settings has been optimised, these settings can be stored in a memory within the amplifier associated with the prevailing occupancy. The parameters of the digital signal processing which may be stored in this way may include the relative volume and phase of the sound from the different speakers as well as the filtering applied to the sound. If the driver prefers to listen to a different radio station when travelling alone, then the station selection may also be stored as one of the parameters.

When the audio system is switched on, the signal from the seat occupant sensors 12 is analysed to determine the current occupancy of the vehicle and the appropriate settings are recovered from the memory to be used as the default settings. In this way, once programmed, the audio system is self adapting and requires less resetting by the driver, thus avoiding a tedious and distracting task.

In vehicles with electric seats, it is also possible to memorise seat positions preferred by different users of the vehicle. On entering a vehicle, the driver may select his preferred seating position either by manual operation of a memory button on the seat or by using a personal entry key.

It is thus possible from the information available from the position of the driver's seat to determine the identity of the person currently driving the vehicle and, in an alternative embodiment of the invention, the detected identity of the driver may additionally be used in the selection of the default settings of the audio system.

Claims

1. An audio system for a motor vehicle having occupant sensors, wherein the audio system includes adjustable digital signal processing, means for receiving from the occupant sensors a signal indicative of the prevailing vehicle occupancy, and means for varying the settings of the digital signal processing in dependence upon the detected occupancy of the vehicle.

2. An audio system as claimed in claim 1, having a memory for storing preferred sets of settings of the digital signal processing for occupancies of the vehicle and means for adopting one of the stored sets of settings as the default settings in dependence upon the detected vehicle occupancy.

3. An audio system as claimed in claim 1 or 2, wherein the settings of the digital signal processing include at least of the relative amplitude of the sound emitted from different speakers in the vehicle, the relative phase of the sound emitted from different speakers, and the filtering applied to sound emitted by the different speakers.

4. A motor vehicle fitted with an audio system as claimed in any preceding claim, wherein the output of the seat occupancy sensors is additionally applied to an airbag deployment system.

5. An audio system constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.