DEVICE AND METHOD FOR PRIORITIZING AUDIO IN A VEHICLE

Field of the invention

The present invention relates to an audio priority device for use in a vehicle including a selecting means arranged to select an audio signal. The present invention also relates to a vehicle including such an audio priority device and to a method for prioritizing audio in a vehicle.

Related art and background of the invention Audio management systems managing signals from a number of audio sources are previously known in the background art. These systems include a plurality of audio sources and a selecting means arranged to select one of the audio signals and to output the selected audio signal to a sound emitting system, as one single sound emitting system handles signals from a plurality of audio sources. Such audio management systems are known from documents EP 0 531 094, EP 1 056 216 and US 6 052 471.

EP 0 531 094 shows a system for integrated cellular telephone and vehicular audio. In this system, an interface selects which one of the cellular telephone signal and the audio system signal to present to a driver of the vehicular. Control signals are sent on a control bus from the cellular telephone and the audio system to the interface, informing the interface whether the cellular phone and the audio system are active or in use. The interface controls, based on these control signals, which audio source to apply to the loud speakers of the system.

EP 1 056 216 shows an audio component system. In this system, a number of audio devices are connected to an amplifier unit. The amplifier unit controls, by the use of a control unit and a control bus connected to each of the audio devices, which device that is to be delivered to the loud speakers of the system.

US 6 052 471 shows an audio receiver that automatically selects an input audio source. The receiver detects which input signals that are present and then a priority

logic block selects, using a priority table, which audio source to provide to the amplifiers. The priority table contains the priorities of the different types of audio sources present and sets the rules for how to select an audio source to be amplified for different scenarios of audio sources present. The priority logic block then, by the use of control signals, controls switches in the receiver such that the chosen audio source is passed through to amplification. The priority of different types of audio sources can for instance be set such that a CD player has a higher priority than a radio, resulting in that the receiver selects the CD player when they both are active. The priority can also be set such that the type of audio source that is most recently turned into an active mode is given the highest priority. That is if a TV is most recently turned on it will be given highest priority and will thus be selected regardless of which other audio sources are being present.

The background art solutions for audio management are all fairly complicated. The background art systems include control circuits and control buses for managing the audio sources and/or complex priority setting and selecting processes.

When installing audio management systems in vehicles, such as trucks, cars, buses and tractors, there arises a problem regarding installation space. The amount of space behind a dashboard available for fitting in audio management systems and cables accompanying these systems is very limited. According to the solutions in background art documents EP 0 531 094 and EP 1 056 216 mentioned above, a control bus is used for controlling which audio source to be selected. This control bus constitutes a problem because of the limited installation space in the vehicle, especially since these audio management systems often are installed after the vehicle has been assembled in a factory.

Weight of the cables can be another problem in solutions involving a large amount of cabling. Troubleshooting can also be very difficult and time consuming when a problem arises in such a system.

Audio management systems that rely on control signals to or from each of the audio source components of the system for handling the selection of audio sources to

output to a sound emitting system, such as a number of loud speakers, will also encounter difficulties relating to the different types of control signaling used by the different audio sources. The different audio sources are often provided by different suppliers and these different audio sources may then have differing control signaling. For instance, the signaling format, such as levels and shapes of the signals, can differ from one audio source to another. The different control signaling can result in difficulties for the audio management system to communicate with all audio source components in the system.

There is further a problem related to complex priority setting and selecting processes of background art solutions, such as the one mentioned in US 6 052 471 above, regarding their capabilities of being able to easily alter priorities of already present audio sources as well as easily assigning priorities to audio sources that are not known by the system at the time of installation of the system, but can be added to the system thereafter. Background art systems need to be reprogrammed when priorities are to be changed or when new audio sources are to be added to the system. Reprogramming is time consuming and expensive for the vehicle owner.

Aim and most important features of the invention It is an object of the present invention to provide an audio priority device that solves the above stated problems.

The present invention aims to provide a future compatible, more simple, less space consuming, lighter and less costly audio priority device than the devices known from audio management system in the background art.

The object is achieved by the above mentioned audio priority device according to the characterizing portion of claim 1 , i.e. that each input connector is arranged invariably assigned with a specific fixed priority level, whereby a present audio signal from an audio source that is connected to one of said input connectors is assigned the specific priority level of that input connector to which the audio source is connected.

One embodiment of the audio priority device according to the present invention comprises that the specific priority level of each input connector is assigned in the selecting means.

Another embodiment of the audio priority device according to the present invention comprises that the input connectors are arranged assigned with mutually different priority levels.

The object is also achieved by the above mentioned vehicle according to the characterizing portion of claim 11.

The object is also achieved by the above mentioned method according to the characterizing portion of claim 12, i.e. that a present audio signal from an audio source connected to an input connector is assigned a priority level corresponding to a specific priority level invariably assigned for that input connector at which the audio source is present, and that all of the audio source input connectors are assigned with mutually different priority levels.

The general idea of the present invention is to assign a priority level to an audio source signal in correspondence to the audio source connector through which the audio source is connected to the audio priority device. The priorities for the audio sources are thus set by the operation of connecting the audio source cables to a suitable audio source input connector, which simplifies changes of the priority order of the audio source signals, since no reprogramming of the device is needed when priorities need to be changed or when new audio sources are added to the system. Further, no control cables between the audio sources and the audio priority device are needed in the audio management system according to the present invention, which makes the system less space consuming, lighter, less costly and easier to troubleshoot.

In different embodiments of the present invention, the amplification of the audio signals is performed in different locations of the system. The amplification circuits may be integrated with the audio sources, with the audio priority device or with a

radio subsequent to the audio priority device. The amplification circuits may also be located in an external amplification stage subsequent of the audio priority device. These different locations of the amplifying circuitry have different advantages. Amplification within the audio sources has the advantage that amplifying circuitry already existing in the audio sources may be used. Amplification within or subsequent to the audio priority device has the advantage that low level signal cables may be used from the audio sources to the location where the amplification takes place, which makes use of more simple, smaller and less costly cables possible. Amplification within, for instance, a radio in a stage subsequent to the audio priority device has the advantage that RDS (Radio Data System) interruptions are very easily achieved.

Detailed exemplary embodiments and advantages of the device and method for prioritizing audio according to the invention will now be described with reference to the appended drawings illustrating some preferred embodiments.

Brief description of the drawings

Fig. 1 shows an audio management system including an audio priority device according to an embodiment of the present invention.

Fig. 2 shows a schematic view of an audio priority device according to the present invention.

Fig. 3 shows an audio management system including an audio priority device according to an embodiment of the present invention.

Fig. 4 shows an audio management system including an audio priority device according to an embodiment of the present invention.

Fig. 5 shows an audio management system including an audio priority device according to an embodiment of the present invention.

Fig. 6 shows a flowchart corresponding to a method of an embodiment of the present invention.

Detailed description of preferred embodiments Fig. 1 shows an audio management system including an audio priority device 100 according to an embodiment of the present invention. In the audio management system, a number of audio sources 111-115, provide audio signals to an audio priority device 100. These audio sources may include music creating systems, such as radios, CD players, mp3 players or the like; communication equipment, such as mobile telephones, communication radios or the like; multimedia equipment, such as DVD players or the like; navigation systems, such as Global Positioning Systems (GPS) or the like; and safety systems, such as Lane Departure Warning (LDW) systems or the like. In an audio management system according to the present invention, any present or future audio source may be incorporated in the system, since this is easily achieved.

Audio signals provided by the audio sources are sent to the audio priority device over audio source cables 121-125. The audio source cables are connected to audio source input connectors 101-105 of the audio priority device 100. The audio priority device 100, e.g. through a selecting means (not shown), chooses or selects which of the audio sources that should be forwarded to a sound emitting system and outputs the signal corresponding to the selected audio source on the output connector 106. The selected signal is sent to an amplifier 140 over an output cable 131 and is received at the amplifier 140 in an amplifier input connector 145. The amplifier 140 amplifies the selected signals and provides them via amplifier output connectors 141-

144 and speaker cables 151-154 to speakers 161-164.

According to the present invention, the selection of audio sources to be forwarded to the sound emitting system is related to which one of the audio source input connectors 101-105 the audio source is connected to. Each one of the audio source input connectors 101-105 is assigned a specific priority level. This priority level is invariably assigned and preferably mutually different for each of the audio source input connectors 101-105, so that every audio source signal, regardless of which type

of signal, present at one of these audio source input connectors 101-105 is assigned the corresponding specific priority level as that assigned to the audio source input connector at which it is present.

The priority level assigned to an audio source signal is, according to the present invention, thus not related to the type of audio source from which it originates, as was the case in background art solutions. The priority level assigned to an audio source signal is instead only related to the specific audio source input connector 101-105 to which the audio source is connected. This means that the priorities for the audio sources are set by the operation of connecting the audio source cables 121 -125 to a suitable audio source input connector 101-105. To change the priority order of the audio source signals, a simple operation of switching the corresponding audio source cable to another audio source input connectors has to be performed.

This is an improvement compared to background art solutions, since no reprogramming of the device is needed when priorities need to be changed or when new audio sources are added to the system. In background art solutions, a complex priority decision table or the like is used for deciding which audio source to select. If a new audio source is added to the background art systems or if priorities are to be changed, this priority decision table need to be altered, which means that the circuits or processors need to be reprogrammed or otherwise adjusted by a skilled person. This can be troublesome, time consuming and costly for the vehicle owner. In an audio management system according to the present invention, an unskilled person can easily switch audio source input connectors used, when priorities for the audio sources are to be changed. He may also easily connect a new audio source to a suitable audio source connector and thereby assigning the new audio source a suitable priority level.

Further, no control cables between the audio sources 111-115 and the audio priority device 100 are needed in the audio management system according to the present invention. Less cabling is an advantage, since cables are space consuming, heavy and expensive. Troubleshooting is further difficult in systems having excessive cabling.

The number of audio sources, audio source cables, audio source input connectors, audio source output connectors, output cables, amplifier input connectors, amplifier output connectors, speaker cables and speakers in the audio management system may vary. The system according to the present invention can easily be modified to any number of audio sources. The number of speakers is set by the amplifier 140 and can thus be varied in a large number of ways. The audio source cables 121-125 and output cable 131 can in this embodiment of the invention include a number of different types of cables. Single cables as well as data buses, such as CAN (Controller Area Network), MOST (Media Oriented Systems Transport), Byteflight, TTCAN (Time Triggered Controller Area Network), Flexray, LIN (Local Interconnected Network) or the like, can be used for these cables.

Further, according to this embodiment of the present invention, the amplifier 140 is common to all the audio sources. All audio sources 121-125 therefore provide low level signals. This has the advantage that the audio source cables 121-125 and the output cable 131 can be implemented using low level signal cables that are less costly, less heavy and smaller in size than high level signal cables. The solution having one common amplifier also has the advantage that a separate amplifier in each of the audio sources can be omitted, since the single amplifier handles amplification of signals from all audio sources. The common amplifier solution according to the present invention thus lowers the overall cost of the audio system.

Fig. 2 shows a schematic view of a possible implementation of an audio priority device 200. The audio priority device 200 has a number of audio source input connectors 201-205 and an output connector 206. Cables conveying audio signals from the audio sources are connected to the connectors 201-205 and are provided to a selecting means 270 on signal lines 271-275. A selection switch 276 within the selecting means 270 is then switched into a position that lets the chosen signal through to the output connector 206. The audio source input connectors 201-205 all have a fix specific priority level assigned to them. For example, the audio source input connector 201 may have been assigned the highest priority level and the audio source input connectors 202-205 may have decreasing priority levels compared to

the audio source input connector 201 , such that connector 202 has a lower assigned priority level than connector 201 , connector 203 has a lower assigned priority level than connector 202 and so forth.

For example, if there are signals present at both the audio source input connectors 201 and 202 then the signal present at audio source input connector 201 will be selected since the selection switch will select the signal present on the input connector having, i.e. being assigned with, the highest priority level. On the other hand, if there is no signal present at audio source input connector 201 but at audio source input connectors 202 and 203 then the signal present at audio source input connector 202 will be selected.

The schematic view of audio priority device 200 shown in fig. 2 is not meant to show all details of the audio priority device, but is more meant to illustrate a general selection process of the device. A more detailed view of the audio priority device 200 may further include signal detection circuits for detection of whether there are signals present at the audio source connectors 201-205, a control circuit for controlling the selection switch 276 and wiring carrying control signals. There are, as is clear to a skilled person, a number of ways to implement the details within the selecting means 200. The implementation may be a hardware implementation, a software implementation or any combination of the both.

Fig. 3 shows an audio management system including an audio priority device according to another embodiment of the present invention. According to this embodiment of the audio priority device, an amplifier 340 is included within the audio priority device casing 300. Otherwise, the audio priority device 300, audio sources 311-315, audio source cables 321-325, audio source input connectors 301-305, amplifier output connectors 342-345, speaker cables 351-354 and speakers 361-364 correspond to the parts in the audio management system shown in fig. 1.

According to the embodiment of the invention shown in fig. 3, the amplifier circuit 340 used for amplifying all audio signals in the audio management system is integrated with the audio priority device 300. This means that no amplification is needed within

the audio sources 311-315, which results in less costly audio resources, and that low level signal cables can be used for the audio source cables 321-325, which results in use of lighter, less costly and less space consuming audio source cables.

Fig. 4 shows an audio management system including an audio priority device according to another embodiment of the present invention. According to this embodiment of the audio priority device, amplifiers 471-475 are included within the casing of the audio sources 411-415. According to this embodiment, the audio priority device 400, audio source cables 421-425 and audio source input connectors 401-405 are designed for coping with high level audio signals being outputted from the amplifiers 471-475. The amplifier output connectors 442-445, speaker cables 451- 454 and speakers 461-464 correspond to the parts in the audio management system shown in fig. 1.

This embodiment has the advantage that it uses amplifiers circuits 471-475 already present in the audio sources 411 -415. The audio sources 411-415 may have amplifying circuits installed by the producer of the audio sources. If it is desirable to use these built in amplifiers, this embodiment is suitable to use.

Fig. 5 shows an audio management system including an audio priority device according to another embodiment of the present invention. According to this embodiment, it is also possible to have an audio source 546, such as a radio, with an integrated amplifier coupled after the audio priority device 500, between the audio priority device 500 and the speakers 561-564 or some of the speakers. According to this embodiment of the audio priority device, an amplifier 540 is included in the audio source 546. The audio priority device 500, audio source cables 521-525, audio source input connectors 501-505, the output connector 506, the output cable 531 , the amplifier input connector 541 , the amplifier output connectors 542-545, speaker cables 551-554 and speakers 561-564 correspond to the parts in the audio management system shown in fig. 1. This embodiment has the advantage that if the audio source 546 itself creates a high priority signal, it can easily output this signal. For instance, if the audio source 546 is a radio having RDS (Radio Data System) then the RDS interruptions may be easily achieved and outputted to the speakers.

As a skilled person realises, combinations of the different solutions in figs. 1 , 3, 4 and 5 may be used in a combination audio management system. That is, different locations of the amplifying circuits may be advantageous for different audio sources. Some audio sources may have integrated amplifiers and for some audio sources it is more advantageous to have the amplifying circuits in a separate amplifying stage, in a subsequent radio or integrated in the audio priority device.

Fig. 6 shows a flowchart corresponding to a method of an embodiment of the present invention. In a first step of the method, an audio priority device receives signals from one or more audio sources being connected to input connectors of the audio priority device. In a second step of the method, the audio signal having the highest priority level received at said input connectors is selected. The priority level of each audio signal is set by a fix priority level specific for the input connector to which it is connected. In a third step of the method, the selected audio signal is outputted to at least one output connector of the audio priority device.

The device and method for prioritizing audio according to the invention may be modified by those skilled in the art, as compared to the exemplary embodiments described above.

As is obvious for a skilled person, a number of other implementations, modifications, variations and/or additions can be made to the above described exemplary embodiments. It is to be understood that the invention includes all such other implementations, modifications, variations and/or additions which fall within the scope of the claims.