WO2014083809A1

WO2014083809A1 - Anomaly detection system and anomaly detection device for speaker wiring

Info

Publication number: WO2014083809A1
Application number: PCT/JP2013/006833
Authority: WO
Inventors: 健志仲村
Original assignee: 株式会社デンソー
Priority date: 2012-11-27
Filing date: 2013-11-21
Publication date: 2014-06-05
Also published as: JP2014107663A

Abstract

A speaker connection assessment unit (5), in a state in which a speaker drive unit (11) outputs in-phase test signals from first and second positive output terminals (O2p and O3p) and outputs in-phase test signals from first and second negative output terminals (O2n and O3n), inputs a first audio signal. The speaker connection assessment unit, in a state in which the speaker drive unit outputs anti-phase test signals from the first and second positive output terminals and outputs anti-phase test signals from the first and second negative output terminals, inputs a second audio signal. The speaker connection assessment unit, on the basis of a difference in levels between the first audio signal and the second audio signal, assesses the connection state of the speaker wiring.

Description

Speaker wiring abnormality detection system and abnormality detection device

Cross-reference of related applications

This disclosure is based on Japanese Patent Application No. 2012-258500 filed on November 27, 2012, the contents of which are incorporated herein.

This disclosure relates to an abnormality detection system and an abnormality detection device for speaker wiring.

Generally, audio amplifiers are used with speakers connected. Since there is a possibility that the speaker wiring may be mistakenly attached to the audio amplifier at the time of manufacture or by a user or the like, the speaker driving integrated circuit has a function of detecting open / short of the speaker wiring (see, for example, Patent Document 1). According to the technique described in Patent Document 1, a current is supplied from an external power source toward one output terminal, and the normal, open, or short state is established based on the voltage or current that appears at the one output terminal. Is detected.

However, if the speaker wiring is configured in a state where the number of output terminals on the speaker driving side is smaller than the number of speakers installed, the speaker wiring can be used even if the function of the conventional speaker driving integrated circuit described above is used. Open / short cannot be detected.

JP 2011-182263 A (corresponding to US 2011/216920 A1)

An object of the present disclosure is to provide an abnormality detection system and an abnormality detection device for a speaker wiring that can reliably detect an open or short even if the number of output terminals on the speaker drive side is smaller than the number of speakers. There is to do.

The speaker wiring abnormality detection system according to an aspect of the present disclosure includes a first speaker, a second speaker, a third speaker, a speaker driving unit, a sound signal input unit, and a speaker connection determination unit. The first speaker includes a first positive input terminal and a first negative input terminal. The second speaker includes a second positive input terminal and a second negative input terminal. The third speaker includes a third positive input terminal and a third negative input terminal.

The speaker driving unit includes a first positive output terminal, a first negative output terminal, a second positive output terminal, and a second negative output terminal. The first positive output terminal is connected to the first positive input terminal by wiring. The first negative output terminal is connected to the first negative input terminal by wiring. The second positive output terminal is connected to the second positive input terminal by wiring. The second negative output terminal is connected to the second negative input terminal by wiring. The second positive output terminal is connected to the third positive input terminal by wiring. The first negative output terminal is connected to the third negative input terminal by wiring.

The sound signal input unit inputs sound output from the first to third speakers. The speaker connection determination unit includes the wiring between the first to third speakers and the first positive output terminal, the first negative output terminal, the second positive output terminal, and the second negative output terminal. Determine the connection status of.

In the speaker connection determination unit, the speaker drive unit outputs a test signal having the same phase from the first positive output terminal and the second positive output terminal, and is in phase from the first negative output terminal and the second negative output terminal. With the test signal output, the first sound signal is input through the sound signal input unit. The speaker connection determining unit outputs a test signal having a reverse phase from the first positive output terminal and the second positive output terminal and reverse from the first negative output terminal and the second negative output terminal. The second sound signal is input through the sound signal input unit in a state in which the phase test signal is output. The speaker connection determination unit determines the connection state based on a level difference between the first sound signal and the second sound signal.

The abnormality detection system can reliably detect an open abnormality or a short abnormality based on a difference in level between the first sound signal and the second sound signal.

A speaker wiring abnormality detection device according to another aspect of the present disclosure includes the speaker connection determination unit.

The above and other objects, configurations, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the following drawings. In the drawing
FIG. 1 is a diagram illustrating a connection state of wiring between a control device and a speaker in the abnormality detection system according to the first embodiment of the present disclosure. FIG. 2 is a block diagram showing an electrical configuration of the abnormality detection system. FIG. 3 is a flowchart showing a flow of inspection relating to the subwoofer according to the first embodiment. FIG. 4 is a diagram illustrating a normal microphone input waveform when a test signal having the same phase or opposite phase is output. FIG. 5 is a diagram illustrating a microphone input waveform at the time of an open abnormality when a test signal having the same phase or opposite phase is output. FIG. 6 is a diagram showing a microphone input waveform at the time of short-circuit abnormality when a test signal having the same phase or opposite phase is output. FIG. 7 is a flowchart illustrating a flow of inspection regarding a subwoofer according to the second embodiment of the present disclosure.

(First embodiment)
Hereinafter, the abnormality detection system for speaker wiring according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 6. The abnormality detection system can be applied to a speaker system mounted inside the automobile C, for example.

As shown in FIG. 2, a driver's seat A1, a passenger seat A2, and a rear seat A3 are installed in the passenger compartment of the automobile C. For example, four speakers 1a to 1d are arranged so as to surround these seats A1 to A3.

The 1-channel speaker 1a is installed in front of the car. The two-channel speaker 1b is installed on the left front side in the vehicle. The 3-channel speaker 1c is installed on the right rear side in the vehicle. The 4-channel speaker 1d is installed on the left rear side in the vehicle.

Also, a subwoofer 1e is installed at the front of the car. The speakers 1a to 1d and the subwoofer 1e for these four channels output sound to the driver seat A1, the passenger seat A2, the rear seat A3, and the like. In addition, a hands-free or voice recognition microphone 2 is installed in a predetermined position (for example, at the headrest, above the driver's seat, or near the steering wheel) in the passenger compartment.

A control unit (ECU) 3 is connected to the speakers 1a to 1d. In FIG. 2, the control device 3 is illustrated outside the vehicle for easy understanding. However, the control device 3 is actually mounted in the automobile C. The control device 3 is also connected to the subwoofer 1e, but the connection is omitted in FIG. The control device 3 has an audio amplifier function.

The control device 3 includes output terminals O1 to O4 for channels 1 to 4 and a microphone input terminal I1. As shown in FIG. 1, the output terminals O1 to O4 include positive output terminals O1p to O4p and negative output terminals O1n to O4n, respectively, and perform differential output from these terminals.

As shown in FIG. 2, the output terminal O1 is assigned one channel for the speaker 1a, and the output terminal O2 is assigned two channels for the speaker 1b. The output terminal O3 is assigned with 3 channels for the speaker 1c, and the output terminal O4 is assigned with 4 channels for the speaker 1d.

As shown in FIG. 1, the speakers 1a to 1e have input terminals S1 to S5, respectively. These input terminals S1 to S5 are respectively provided with positive input terminals S1p to S5p and negative input terminals S1n to S5n for differential input.

The speaker wirings 4a to 4d are respectively connected to the input terminals S1 to S4 of the 1 to 4 channel speakers. More specifically, the positive wirings 4ap to 4dp of the speaker wirings 4a to 4d are connected between the positive output terminals O1p to O4p of the output terminals O1 to O4 and the positive input terminals S1p to S4p of the input terminals S1 to S4. Connecting. Also, the negative side wires 4an to 4dn of the speaker wires 4a to 4d connect between the negative output terminals O1n to O4n of the output terminals O1 to O4 and the negative input terminals S1n to S4n of the input terminals S1 to S4.

Further, the positive wiring 4ep of the speaker wiring 4e connects between the positive output terminal O3p of the three channels and the positive input terminal S5p of the subwoofer 1e. Further, the negative wiring 4en of the speaker wiring 4e connects between the 2-channel negative output terminal O2n and the negative input terminal S5n of the subwoofer 1e.

The abnormality detection system of the present embodiment is configured by connecting speaker wirings 4a to 4e using four-channel output terminals O1 to O4 so as to drive more speakers 1a to 1e than the number of output terminals. Yes.

The internal block configuration of the control device 3 will be described with reference to FIG. The control device 3 includes a CPU 5 as a speaker connection determination unit, a memory 6 and the like. The control device 3 includes hardware blocks such as a sound input processing unit 9, a sound output processing unit 10, and an amplifier unit 11. The CPU 5 of the control circuit 3 has a function of outputting sound signals to the speakers 1a to 1e connected to the outside in accordance with a program stored in the memory 6.

The sound input processing unit 9 is a block configured with hardware having a function for inputting sound from the microphone 2. The sound output processing unit 10 is a block configured by hardware having a function for outputting sounds from the speakers 1a to 1e. The amplifier unit 11 amplifies the sound signal using, for example, a class D amplifier and drives the speakers 1a to 1e. The amplifier unit 11 normally outputs sound signals to the speakers 1a to 1e, but includes an output circuit that sets the output impedance to high impedance for each channel in order to invalidate each channel during testing. These can be appropriately switched by the CPU 5 according to each operation state such as an actual use state or an inspection state.

An inspection method and an abnormality detection method for inspecting the connection state of the speaker wires 4a to 4d will be described below. When a vehicle manufacturer constructs a speaker system in the automobile C, the speakers 1a to 1e and the control device 3 are installed in the automobile C. The output terminals O1 to O4 of the control device 3 and the speakers 1a to 1e are connected by speaker wires 4a to 4e. Thereafter, the inspector inspects the connection state of the speaker wires 4a to 4e.

When the inspector inspects the connection state of the speaker wires 4a to 4e, the inspection device 13 is connected to the control device 3 through the controller area network (CAN) 12. The inspection device 13 transmits various inspection commands to the control device 3 through the CAN 12. Thereby, various inspections are performed by the CPU 5 of the control device 3.

The memory 6 stores test sound source data (test signal: for example, one or a plurality of single frequency sounds) in advance. The sound source data is prepared in advance according to the acoustic frequency characteristics of the speakers 1a to 1e. In the present embodiment, the sound source data is particularly adjusted to the acoustic frequency characteristics of the subwoofer 1e. In particular, since the frequency characteristic of the subwoofer 1e is adjusted to a relatively low frequency (eg, <100 Hz) among audible sounds, the sound source data includes a single frequency having a predetermined frequency (eg, about 70 Hz) that matches the frequency characteristic. Frequency sound is prepared. In the present embodiment, a relatively low frequency sound is used as the sound source data among the audible sounds. For example, when the parallel connection target speaker is a high sound speaker such as a tweeter (for example,> 1 kHz), It is preferable to use sound source data (for example, a single frequency sound of 2 kHz) that matches the frequency characteristics of the target speaker. This is because a loud sound is likely to be output from the high sound speaker in a normal state.

The sound output processing unit 10 outputs sound signals to the speakers 1 a to 1 e through the amplifier unit 11 using reference sound source data stored in the memory 6 in accordance with a control signal from the CPU 5. Each speaker 1a to 1e outputs a sound according to a sound signal given through each speaker wiring 4a to 4e. The sound input processing unit 9 inputs and processes the sound output from the speakers 1a to 1e, and outputs the processing signal to the CPU 5 or the like.

<Method for Inspecting Appropriate Connection of

Speaker Channels

4a and 4d for 1 Channel and 4 Channel>
As shown in FIG. 1, the output terminal O1 of one channel is directly connected to the input terminal S1 of the speaker 1a. The 4-channel output terminal O4 is directly connected to the input terminal S4 of the speaker 1d. Since these 1 channel and 4 channel operate independently, it is good to inspect using a general diagnostic function. For example, you may test | inspect using the technique of patent document 1 mentioned above. Since it is not related to the feature of the present application, detailed description thereof is omitted.

<Method for Inspecting Appropriate Connection of 2 Channel and 3

Channel Wirings

4b and 4c>
The output of the amplifier unit 11 is separated for each channel. For this reason, when the CPU 5 of the control device 3 accepts a 2-channel or 3-channel inspection command, the amplifier unit 11 holds the output impedance of the output terminal of the channel other than the channel to which the test signal is output at a high impedance. .

For example, when two channels are inspected, the amplifier units 11 of the 1, 3, and 4 channels hold their outputs in a high impedance state. For this reason, even if the speaker wiring 4e is connected to the output terminal O3p through the subwoofer 1e, the energization path returning to the amplifier unit 11 is cut off. Therefore, the 2-channel output of the amplifier unit 11 is independently connected to the speaker 1b, and it is possible to individually determine 2-channel open abnormality / short-circuit abnormality.

Also, when inspecting 3 channels, the amplifier units 11 of 1, 2 and 4 channels hold their outputs in a high impedance state. For this reason, as described above, even if the speaker wiring 4e is connected to the output terminal O2n through the subwoofer 1e, the energization path returning to the amplifier unit 11 is cut off, and the open / short abnormality of the three channels is prevented. Can be judged individually.

<Inspection Method for Subwoofer 1e and Appropriateness of Wiring Connected to Subwoofer 1e>
Hereinafter, the operation state of the subwoofer 1e and the inspection method of the connection suitability of the wiring 4e will be described with reference to the flowchart of FIG. Since sound can be output independently to the first and fourth channels, the CPU 5 of the control device 3 invalidates the first and fourth channel outputs of these amplifiers 11. Although the present embodiment shows a disabled form, the sound output need not be disabled. Then, the CPU 5 of the control device 3 outputs test signals only to the output terminals O2 and O3 of the 2-channel and 3-channel.

Specifically, first, the CPU 5 of the control device 3 outputs a test signal (sound source data stored in the memory 6) in-phase to the 2nd channel and the 3rd channel from the amplifier unit 11 (S1). Then, sounds according to the test signal are output from the

speakers

1b, 1c, and 1e.

FIG. 4A shows the in-phase output sound and the input sound of the microphone 2 when the wiring connection state is normal. The

speakers

1b and 1c output in-phase with each other, but the microphone 2 receives sounds according to the output sounds of these

speakers

1b and 1c. When the connection of the wiring 4e of the subwoofer 1e is normal, sound is output from the subwoofer 1e. Although the output of the subwoofer 1e shown in FIG. 4 (a) is smaller than the output of other channels, this corresponds to the difference in input impedance between the

speakers

1b, 1c, and 1e. If the output of the subwoofer 1e is large, the input sound of the microphone 2 is also large.

If the frequency of the test signal is adjusted according to the frequency characteristics of the subwoofer 1e, this sound will be output even more. When the sound is input through the microphone 2, the control device 3 stores the digital data in the memory 6 or the like (S2). This stored digital data is referred to as recording sound MIC1 (corresponding to the first sound signal).

Then, the CPU 5 of the control device 3 stops the output of the in-phase test signal, and outputs the test signal of the opposite phase from the amplifier unit 11 to the second channel and the third channel (S3). Then, a sound corresponding to the test signal is output from the

speakers

1b, 1c, 1e.

FIG. 4B shows the reverse phase output sound and the input sound of the microphone 2 when the connection state of the wiring is normal. The

speakers

1b and 1c output in reverse phase with each other, but the microphone 2 receives sounds according to the output sounds of these

speakers

1b and 1c. However, since signals having the same phase are input to the input terminals S5p and S5n of the subwoofer 1e, the output of the test signal of the subwoofer 1e is 0 in principle and the subwoofer 1e does not output sound in principle.

Note that a DC bias level may be applied to each of the input terminals S5p and S5n according to the output characteristics of the amplifier unit 11, and therefore, a minute DC bias level is illustrated in FIG. No sound is output from the subwoofer 1e. Therefore, the input sound level of the microphone 2 shown in FIG. 4B is smaller than the input sound level of the microphone 2 shown in FIG.

When the sound in the reverse phase output state is input from the microphone 2, the control device 3 stores it as digital data in the memory 6 or the like (S4). This stored digital data is referred to as recording sound MIC2 (corresponding to the second sound signal). Then, the control device 3 stops the output of the test signal having the opposite phase, performs frequency analysis by FFT on the recording sounds MIC1 and MIC2 (S5, S7), and each analysis result has a predetermined frequency component corresponding to the test signal. Is extracted (S6, S8). The reason why the frequency component corresponding to the test signal is extracted by frequency analysis is to eliminate the influence of reverberation sound in the vehicle C and external environmental sound as much as possible.

Then, the CPU 5 of the control device 3 calculates the level difference between the extracted components (S9), and determines whether this level difference is equal to or higher than a predetermined level (S10). When the level difference is greater than or equal to the predetermined level, the CPU 5 determines that the connection state is normal and outputs a determination result (S11). When the level difference is less than the predetermined level, the CPU 5 determines that the open abnormality or the short abnormality, and outputs the determination result (S12).

If it is difficult to determine an abnormality in an inspection using a test signal having a single frequency sound, it is preferable to inspect using a test signal having a plurality of frequencies by sweeping or changing the frequency of the test signal stepwise. In this case, the reliability of inspection can be improved.

FIG. 5 shows the input sound level of the microphone 2 when a wiring open abnormality occurs during in-phase output or reverse-phase output. FIG. 6 shows the input sound level of the microphone 2 when a short circuit abnormality occurs during in-phase output or reverse-phase output.

For example, when the speaker wiring 4ep or 4en is disconnected (open) from the subwoofer 1e due to some influence, the input terminal S5 of the subwoofer 1e and the output terminal O2n or O3p are disconnected. Then, no sound is output from the subwoofer 1e at the time of in-phase output and at the time of reverse-phase output, so the input sound of the microphone 2 does not substantially change even when the in-phase output and the reverse-phase output are compared. Therefore, the level difference between (a) and (b) in FIG. 5 is smaller than the level difference between (a) and (b) in FIG.

Also, for example, when the speaker wirings 4ep and 4en are brought into contact and short-circuited due to some influence, the input impedance on the subwoofer 1e side viewed from the output terminals O2n and O3p becomes 0 in principle. At this time, as shown in FIG. 6, the voltage is not applied to the input terminal S5 of the subwoofer 1e in both the in-phase output and the reverse-phase output. As in the case of the open abnormality described above, no sound is output from the subwoofer 1e, so that the input sound of the microphone 2 does not substantially change even when the in-phase output and the opposite-phase output are compared. Or, the in-phase output is lower than the reverse-phase output. Therefore, the level difference between (a) and (b) in FIG. 6 is smaller than the level difference between (a) and (b) in FIG.

That is, if the connection is normal, the level difference becomes larger than the predetermined level. However, when some abnormality such as an open / short abnormality occurs, the level difference becomes less than the predetermined level. Can be detected.

When the inspector detects the output of step S12, the inspector can determine that some wiring connection abnormality (open or short) has occurred, inspect the connection state, and confirm the connection as necessary. When the inspector finds a connection abnormality, the connection can be returned to normal.

As described above, according to the present embodiment, the CPU 5 of the control device 3 determines whether the connection state of the subwoofer 1e is appropriate according to the level difference between the recording sound MIC1 and the recording sound MIC2, and detects an open / short abnormality. Therefore, the abnormality can be detected with high reliability. Further, the CPU 5 of the control device 3 detects the open / short abnormality by determining the appropriateness of the connection state of the subwoofer 1e based on the level difference of the predetermined frequency component corresponding to the test signal extracted by frequency analysis. Even if the sound wave propagation state of each of the speakers 1b to 1c changes due to the influence of reflection or the like, the abnormality can be detected with reliability, and the sound field environment can be flexibly dealt with.

When a predetermined frequency that matches the acoustic frequency characteristics of the subwoofer 1e is used as the test signal, the sound from the subwoofer 1e increases when the wiring connection of the subwoofer 1e is normal, and the level difference during normal connection increases. Thereby, the suitability of the connection state of wiring can be determined with high reliability.

In this embodiment, the speaker 1b corresponds to the first speaker, the speaker 1c corresponds to the second speaker, and the subwoofer 1e corresponds to the third speaker. The microphone 2 corresponds to a sound signal input unit, the CPU 5 corresponds to a speaker connection determination unit, and the amplifier unit 11 corresponds to a speaker driving unit.

(Second Embodiment)
The inspection flow of the abnormality detection system according to the second embodiment of the present disclosure will be described with reference to FIG. In the present embodiment, the suitability of connection is determined based on the level difference obtained by comparing the sound pressure levels. In FIG. 7, the same step number is assigned to a portion that performs the same process as the process illustrated in FIG. Further, in FIG. 7, a part that performs a process similar to the process illustrated in FIG.

After recording the input sound of the microphone 2 at the time of the in-phase output and the reverse-phase output to make the recording sounds MIC1 and MIC2 respectively (S2, S4), the control device 3 performs the sound of the recording sound MIC1 in step S9a instead of step S9. The level difference is calculated by subtracting the sound pressure level of the recording sound MIC2 from the pressure level. That is, the level difference is calculated without the frequency analysis processing described in the above embodiment. Even if such processing is performed, it is possible to detect an open abnormality / short abnormality as in the above-described embodiment. Also in this embodiment, erroneous wiring can be accurately determined.

(Other embodiments)
The present disclosure is not limited to the above-described embodiment. For example, the following modifications or expansions are possible.

Although the embodiment applied to the system in the interior of the car C is shown, the system is not limited to the system in the car C as long as the connection relationship between the speaker and the control device is satisfied, and is installed in a general home. You may apply to.

Although the input terminals S5p and S5n of the subwoofer 1e are respectively connected to the three-channel positive output terminal O3p and the two-channel negative output terminal O2n of the control device 3, the input terminal S5p is connected to the control device 3. It may be applied to a form in which the two-channel positive output terminal O2p is connected and the input terminal S5n is connected to the three-channel negative output terminal O3n.

Claims

A first speaker (1b) comprising a first positive input terminal (S2p) and a first negative input terminal (S2n);
A second speaker (1c) comprising a second positive input terminal (S3p) and a second negative input terminal (S3n);
A third speaker (1e) comprising a third positive input terminal (S5p) and a third negative input terminal (S5n);
A first positive output terminal (O2p); a first negative output terminal (O2n); a second positive output terminal (O3p); and a second negative output terminal (O3n). The first positive input terminal is connected to the first positive input terminal by a wiring (4 bp), the first negative output terminal is connected to the first negative input terminal by a wiring (4bn), and the second positive output terminal is connected to the second positive input terminal. Connected by wiring (4cp), the second negative output terminal connected to the second negative input terminal by wiring (4cn), and the second positive output terminal connected to the third positive input terminal by wiring (4ep). A speaker driving unit (11) in which the first negative output terminal is connected to the third negative input terminal by a wiring (4en);
A sound signal input unit (2) for inputting output sounds of the first to third speakers;
A speaker for determining a connection state of the wiring between the first to third speakers and the first positive output terminal, the first negative output terminal, the second positive output terminal, and the second negative output terminal. A connection determination unit (5),
In the speaker connection determination unit, the speaker drive unit outputs a test signal having the same phase from the first positive output terminal and the second positive output terminal, and is in phase from the first negative output terminal and the second negative output terminal. With the test signal output, the first sound signal is input through the sound signal input unit,
The speaker connection determining unit outputs a test signal having a reverse phase from the first positive output terminal and the second positive output terminal and reverse from the first negative output terminal and the second negative output terminal. With the phase test signal output, the second sound signal is input through the sound signal input unit,
The speaker connection determination unit is a speaker wiring abnormality detection system that determines the connection state based on a level difference between the first sound signal and the second sound signal.
The speaker connection determination unit determines the connection state based on a level difference of a predetermined frequency component corresponding to the test signal extracted by frequency analysis of the first sound signal and the second sound signal. Anomaly detection system described in 1.
The abnormality detection system according to claim 1, wherein the speaker connection determination unit determines the connection state based on a difference in sound pressure level between the first sound signal and the second sound signal.
The abnormality detection system according to any one of claims 1 to 3, wherein the speaker connection determination unit uses a signal having a predetermined frequency according to a sound output frequency characteristic of the third speaker as the test signal.
5. The abnormality detection system according to claim 1, wherein the abnormality detection system is configured for mounting on a vehicle.
An abnormality detection device comprising the speaker connection determination unit constituting the abnormality detection system according to any one of claims 1 to 5.