JP4692106B2 - Warning device for vehicle - Google Patents

Description

  The present invention relates to a vehicular warning device that generates a warning sound according to the state of an engine or the like in a vehicle.

In order to perform safe driving, it is necessary to detect deterioration of engine oil and deterioration of engine conditions at an early stage, and to prevent failure in advance. However, since the driver concentrates on driving while driving, the driver is often unaware of the deterioration of the engine condition. Also, if engine oil is not very careful, it is likely that the oil will not be replaced after the replacement period. In view of such a problem, for example, Patent Document 1 proposes a device that detects an engine sound frequency, an engine temperature, and the like with a sensor and generates a warning sound when an abnormality of the engine is recognized from the result.
Utility model registration No. 3096557

  According to the device described in Patent Document 1, the driver can check whether an abnormality has occurred in the engine or the like when the warning sound is heard, and can take necessary accident prevention measures. However, if the warning sound is a buzzer sound or a chime sound, such a sound lacks vividness and gradually attracts the driver's attention. On the other hand, if the warning sound surprises the driver, it will hinder safe driving.

  The present invention has been made in view of the circumstances described above, and it is an object of the present invention to provide a vehicle warning device that can generate a convincing sound for a driver as a warning sound indicating the state of the vehicle. And

The present invention provides a speaker provided in a vehicle, an engine sound signal generating means for generating an engine sound signal representing an engine sound or a pseudo engine sound generated in the vehicle, and supplying the engine sound signal to the speaker, and a state of the vehicle When a predetermined monitoring result is obtained, a control unit that generates a modulation signal that periodically oscillates, and a modulation unit that performs amplitude modulation of an engine sound signal supplied to the speaker by the modulation signal, A vehicular warning device is provided.
According to this invention, since the engine sound signal is amplitude-modulated by the generation of the warning information, and an unpleasant engine sound is output from the speaker, the driver is made aware of the generation of the warning information and is appropriately Treatment can be performed. In addition, the sound reproduced from the speaker is an engine sound that is originally generated, so it is an unpleasant sound, but it is a natural sound for the driver and does not interfere with safe driving. .

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a vehicle warning device according to an embodiment of the present invention. This vehicle warning device monitors the state of the vehicle, and when this warning detects the arrival of a warning time for engine inspection or oil change, it applies amplitude modulation to the engine sound signal obtained by sound collection. Provided to the driver.

  In the example shown in FIG. 1, the intake sound, the sound in the engine room, the exhaust sound, and the outside sound are selected as components of the engine sound, and the microphones 11 to 14 are placed at positions where they can be collected. Has been placed. The filters 21 to 24 are components having characteristics as intake sounds, components having characteristics as sounds in the engine room, components having characteristics as exhaust sounds, and sounds outside the vehicle from the electric signals obtained from the microphones 11 to 14. Is a filter that selects and outputs each component having the above characteristics. The mixer 30 synthesizes the left and right two-channel engine sound signals XL and XR from the sound signals that have passed through the filters 21 to 24 and outputs them. The modulation unit 40 is a device that amplitude-modulates the engine sound signals XL and XR with the modulation signal m (t) given from the warning control unit 100 and outputs the engine sound signals YL and YR. The warning controller 100 and the modulation signal m (t) will be described later.

  The signal processing unit 50 is a circuit that performs predetermined signal processing on the engine sound signals YL and YR, respectively, and outputs them to the left and right two-channel speakers 60L and 60R. Engine sound signals YL and YR are ATT (attenuators) 51L and 51R, HPFs (high-pass filters) 52L and 52R, and LPFs (low-pass filters) corresponding to the left and right channels in the signal processing unit 50. 53L and 53R and sound insulation characteristic filters 54L and 54R are sequentially passed through and output as final engine sound signals ZL and ZR to speakers 60L and 60R, respectively.

  Here, ATTs 51L and 51R are circuits that adjust the levels of engine sound signals YL and YR to levels suitable for driving the speakers. The HPFs 52L and 52R and the LPFs 53L and 53R remove unnecessary high frequency components and low frequency components that are not suitable for output from the speakers 60L and 60R from the output signals of the ATTs 51L and 51R. The sound insulation characteristic filters 54L and 54R are filters that simulate the sound insulation characteristic of the vehicle body, that is, the characteristic of the sound transmission system from the engine to the driver's ear through the vehicle body.

The warning control unit 100 includes a vehicle state determination unit 101 and a modulation signal generation unit 102 that generates the above-described modulation signal m (t) under the control of the vehicle state determination unit 101. FIG. 2 is a waveform diagram illustrating the waveform of the modulation signal m (t) generated by the modulation signal generation unit 102. In the present embodiment, the modulation signal generation unit 102 generates a sine wave having “1” as the maximum amplitude value, more specifically, a modulation signal m (t) having a waveform represented by the following equation.
m (t) = 1− (k / 2) · (sin (2πft + θ) +1) (1)
In the above equation (1), f is the modulation frequency of the modulation signal m (t), k is the modulation depth, and is determined by an instruction from the vehicle state determination unit 101.

  The vehicle state determination unit 101 monitors the measurement results of various sensors such as the engine speed sensor 111 and the mileage meter 112, thereby providing warning information such as the predefined continuous high-speed rotation operation and the arrival of the oil change time. Has the function to occur. The warning information is defined in advance as to its generation requirement, that is, what kind of monitoring result is obtained for the vehicle. The vehicle state determination unit 101 generates warning information when a monitoring result satisfying any warning information generation requirement is obtained, and the modulated signal m (t) in a form defined in advance for the warning information. Is generated to the modulation signal generation unit 102. When no warning information is generated, the vehicle state determination unit 101 instructs the modulation signal generation unit 102 to 0 as the modulation depth k. In this case, since the modulation signal generation unit 102 outputs a constant value “1” as the modulation signal m (t), the engine sound signals XL and XR are supplied as they are to the signal processing unit 50 as the modulated engine sound signals YL and YR. The

When some warning information is generated, the vehicle state determination unit 101 instructs the modulation signal generation unit 102 to specify a modulation depth k in a range of 0 <k <1. Further, the vehicle state determination unit 101 calculates a fundamental frequency f0, which is a fundamental frequency of engine sound, from the number of cylinders N and the engine speed r (rpm) according to the following equation (2). Next, the vehicle state determination unit 101 calculates the modulation frequency f by the following equation (3) using the basic frequency f0 and the frequency correction coefficient j, and instructs the modulation signal generation unit 102 to use the modulation frequency f.
f0 = (1/60) · r · (N / 2) (Hz) (2)
f = j · f0 (Hz) (3)
However, the above equation (2) represents the fundamental frequency f0 in the case of a 4-cycle engine.

  The parameter memory 120 stores a modulation depth k and a frequency correction coefficient j in association with various kinds of warning information such as continuous high-speed rotation operation and the arrival of the oil change time. When any warning information is generated, the vehicle state determination unit 101 reads the modulation depth k and the frequency correction coefficient j corresponding to the warning information in the parameter memory 120, and reads the modulation depth k and the frequency correction coefficient j. The modulation signal generation unit 102 is instructed with the modulation frequency f calculated from the above. The modulation signal generation unit 102 generates a modulation signal m (t) having the instructed modulation depth k and modulation frequency f, and supplies the modulation signal m (t) to the modulation unit 40. Here, when the frequency correction coefficient j is 1, the modulation signal generation unit 102 modulates the modulation signal of the above equation (1) so that the explosion timing of the engine coincides with the peak timing of the modulation signal m (t). The phase angle θ of m (t) is adjusted. This is to prevent variation in the phase difference between the modulation signal m (t) and the fundamental sound component of the engine sound when the frequency correction coefficient j is 1, and prevent the influence from appearing in the modulated engine sound signals YL and YR. Because.

  In the modulation unit 40, the engine sound signals XL and XR are amplitude-modulated by the modulation signal m (t) generated by the modulation signal generation unit 102, and the modulated engine sound signals YL and YR obtained thereby are passed through the signal processing unit 50. Through the speakers 60L and 60R. The engine sound to which the amplitude modulation is applied in this way can give the driver an uncomfortable feeling, and therefore can tell the driver that some measure must be taken.

  The degree of discomfort can be adjusted by the modulation depth k and the frequency correction coefficient j. Increasing the modulation depth k is thought to increase the discomfort of engine sound output from the speakers 60L and 60R. Further, as the frequency correction coefficient j, the engine sound output from the speakers 60L and 60R should be a value that cannot be expressed by a fraction of a simple integer combination such as 3/2 times or 5/4 times. It is thought that the degree of discomfort increases. Therefore, the modulation depth k and the frequency correction coefficient j are prepared assuming various warning urgency levels so that the discomfort level according to the warning urgency level, such as the degree of engine overload, is provided. You may select and use the one according to the degree of urgency. Further, depending on the type of alarm information, it may be preferable to gradually or gradually increase the degree of discomfort as time elapses or travel distance increases. In such a case, a plurality of combinations of the modulation depth k and the frequency correction coefficient j are prepared, and each set is sequentially selected according to the passage of time or the mileage and used for amplitude modulation of the engine sound. Good. Alternatively, the modulation depth k and the frequency correction coefficient j are defined as functions of appropriate independent variables (for example, travel distance and time), and are function values according to changes in the independent variables after generation of warning information. The modulation depth k and the frequency correction coefficient j may be changed.

  Next, the operation of this embodiment will be described. In this embodiment, when no warning information is generated, a constant value “1” is generated as the modulation signal m (t) as described above. Therefore, the engine sound signals XL and XR indicating the engine sound obtained from the vehicle are supplied to the signal processing unit 50 as they are, and the driver listens to the normal engine sound in the vehicle.

  Depending on the driving situation of the vehicle thereafter, warning information may be generated. For example, the vehicle state determination unit 101 monitors the output signal of the engine speed sensor 111 and performs continuous high-speed rotation operation when a period in which the engine speed per unit time is equal to or greater than a predetermined value continues for a predetermined time or longer. It is determined that it has been broken, and warning information to that effect is generated. When this warning information is generated, the vehicle state determination unit 101 reads the modulation depth k and the frequency correction coefficient j corresponding to the warning information “continuous high-speed rotation operation” in the parameter memory 120, and the modulation depth k. And the modulation signal generation unit 102 is instructed about the modulation frequency f calculated from the frequency correction coefficient j.

  The modulation signal generation unit 102 generates a modulation signal m (t) according to this instruction, the engine sound signals XL and XR are amplitude-modulated by the modulation signal m (t), and the speakers 60L and 60R are sent via the signal processing unit 50. Is output from. Since the engine sound to which the amplitude modulation is applied in this way gives the driver unpleasant feeling, it is possible to tell the driver that it is necessary to take measures such as checking the engine.

  In this embodiment, a reset button is provided that is operated when oil is changed. The vehicle state determination unit 101 has a function of monitoring the travel distance of the vehicle after the reset button is operated and detecting the arrival of the oil change time. FIG. 3 is a time chart showing an example of an oil change warning operation performed according to this function.

  When the oil change is performed and the reset button is operated, the vehicle state determination unit 101 initializes the modulation depth k to “0” and the frequency correction coefficient j to “1”. Thereafter, the vehicle state determination unit 101 monitors the difference between the travel distance indicated by the travel distance meter 112 and the travel distance when the reset button is operated, that is, the travel distance after the oil change.

  The parameter memory 120 stores in advance a modulation depth k and a frequency correction coefficient j in accordance with the travel distance after the oil change. The vehicle state determination unit 101 reads the modulation depth k and the frequency correction coefficient j corresponding to the travel distance after the oil change from the parameter memory 120, and instructs the modulation signal generation unit 102 of the modulation depth k and the modulation frequency f. I do.

  In the example shown in FIG. 3, the oil change is scheduled at the time when the travel distance after the oil change becomes L3. Then, in the section of the traveling distances L1 to L2 before the oil replacement is scheduled, an operation of increasing the modulation depth k from 0 to a predetermined value a according to the traveling distance while the frequency correction coefficient j is 1 is performed. During this time, the degree of amplitude modulation of the engine sound output from the speakers 60L and 60R gradually increases, so the driver notices that the oil replacement schedule is approaching. Thereafter, in the section of the travel distances L2 to L3, the modulation depth k is maintained at the predetermined value a and the frequency correction coefficient j is maintained at 1. When the travel distance becomes L3 and the oil change schedule is reached, an operation for shifting the frequency correction coefficient j from 1 to 1.1 is performed in the subsequent travel distances L3 to L4, and the travel distances L3 to L5 ( In the section of L5> L4), an operation for increasing the modulation depth k from the predetermined value a to a predetermined value b larger than this is performed. For example, as described above, this operation is performed by calculating a value of a function of a frequency correction coefficient and a modulation depth using a predefined travel distance as an independent variable. In this case, the modulation frequency f is different from the fundamental frequency f0 of the engine sound, and the frequency correction coefficient j, which is the ratio between the modulation frequency f and the fundamental frequency f0, is a value that cannot be expressed as a fraction by a simple integer combination. Therefore, the engine sound output from the speakers 60L and 60R is an unpleasant sound. Further, since the modulation depth k gradually increases after the oil replacement schedule has passed, the discomfort level of the engine sound output from the speakers 60L and 60R gradually increases. Persuaded by this unpleasant engine sound, the driver changes oil.

  As described above, according to the present embodiment, when warning information such as continuous high-speed rotation operation or the arrival of the oil change time occurs, the engine sound is subjected to amplitude modulation, and the unpleasant engine sound obtained thereby. Is output from the speakers 60L and 60R, the driver can be made aware of the occurrence of the warning information and can take appropriate measures. In addition, the sound output from the speakers 60L and 60R is a processed sound of the engine sound that is originally generated. Therefore, although it is an unpleasant sound, it is a natural sound for the driver and is safe driving. It won't interfere.

Although one embodiment of the present invention has been described above, other embodiments are possible for the present invention. For example:
(1) For example, j = 1.1 at the time of oil change, j = 1.3 at the time of continuous high-speed rotation operation, and so on. The type of warning information may be determined by listening to the modulated engine sound.
(2) The amplitude modulation of the engine sound signal may be intermittently performed at regular time intervals, as in the case of an intermittent telephone bell. By doing so, it becomes easy to understand that amplitude modulation is performed.
(3) In the above (2), the time interval for applying amplitude modulation and the duration of amplitude modulation may be changed depending on the type of warning information such as oil change and continuous high-speed rotation operation.
(4) In the above embodiment, the modulation unit 40 is provided in the subsequent stage of the mixer 30. Similarly, the modulation unit that performs amplitude modulation on the input signal with the modulation signal m (t) and outputs the modulated signal is provided in the mixer 30. You may provide in all or one part of the filters 21-24 of the preceding stage. Alternatively, an amplitude modulation unit is provided in all of the filters 21 to 24, and, for example, when oil change warning information is generated, the modulation unit in the filter 23 performs amplitude modulation so that the exhaust sound component in the engine sound is generated. For example, when warning information for continuous high-speed rotation operation occurs, the modulation unit in the filter 22 performs amplitude modulation to make the sound component in the engine room in the engine sound uncomfortable. The modulation unit that performs amplitude modulation may be switched depending on the type of warning information.
(5) In the above embodiment, the engine sound is picked up, and amplitude modulation is applied thereto to generate an engine sound for warning. However, instead of actually collecting the engine sound in this way, the engine sound waveform data is read from the memory that stores the engine sound waveform data in advance at a read speed corresponding to the engine speed, and the pseudo engine sound signal is reproduced. Then, the pseudo engine sound signal may be amplitude-modulated according to the warning information and output from the speaker. According to this aspect, an effect similar to that of the above embodiment can be obtained even in a vehicle that does not have an engine and travels by a motor.
(6) In the above embodiment, a sine wave is used as the modulation signal m (t). However, the modulation signal m (t) only needs to be periodically oscillated, and may be a triangular wave or a rectangular wave.

It is a block diagram which shows the structure of the warning device for vehicles which is one Embodiment of this invention. It is a wave form diagram which illustrates the waveform of modulated signal m (t) in the embodiment. It is a time chart which shows the operation example of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Warning control part, 101 ... Vehicle state determination part, 102 ... Modulation signal generation part, 111 ... Engine speed sensor, 112 ... Travel distance meter, 120 ... Parameter memory, 11-14 ... Microphone 21-24... Filter, 30... Mixer, 40... Modulation section, 50... Signal processing section, 60L, 60R.

Claims (4)

A speaker provided in the vehicle;
An engine sound signal generating means for generating an engine sound signal representing an engine sound or a pseudo engine sound generated in the vehicle and supplying the engine sound signal to the speaker;
The oil change timing or the continuous high-speed rotation of the engine is monitored based on the measurement results from the mileage meter or engine speed sensor, and when a predetermined monitoring result is obtained, a modulation signal that oscillates periodically is generated. Control means to
Modulation means for performing amplitude modulation of an engine sound signal supplied to the speaker by the modulation signal;
A vehicle warning device characterized by comprising: The control means includes
A modulation signal generation unit for generating an instructed modulation signal;
When a monitoring result that satisfies the warning information generation requirements is obtained for warning information indicating the arrival of the oil change time and warning information indicating the continuous high-speed rotation operation of the engine, the corresponding warning information is generated. The vehicle warning device according to claim 1, further comprising: a vehicle state determination unit that instructs the modulation signal generation unit to generate a modulation signal in a form defined in advance for the warning information . Sound collecting means for collecting engine sound generated in the vehicle;
3. The vehicle warning device according to claim 1, wherein the engine sound signal generation unit generates an engine sound signal representing the engine sound collected by the sound collection unit. 4. Means for detecting the timing of engine explosion,
The vehicle state determination unit has a frequency obtained by multiplying a basic frequency, which is an engine explosion timing frequency, by a frequency correction coefficient determined by the warning information, and a modulation signal having an amplitude determined by the warning information. The vehicle warning device according to claim 2 , wherein generation is instructed to the modulation signal generation unit.

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