JPS6121846B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention is applicable to driving in a state where the driver's attentiveness or judgment is diminished or in a distracted state (hereinafter referred to as unconscious driving), such as falling asleep or thinking while driving in a vehicle such as a car. This invention relates to a driving warning device for preventing.

Conventionally, this type of device detects the driver's grip strength on the steering wheel, the frequency of operation, or brain waves.
This has led to some warnings against unconscious driving.

However, the above-mentioned conventional device has a complicated structure, is expensive, and is troublesome to use.
The drawback was that it was not practical.

Therefore, an alarm sound is emitted to the driver to draw the driver's attention, and when the driver issues a response sound to the alarm sound, the alarm sound stops generating, and thereafter the alarm sound is emitted at a predetermined period. A driving warning system has been devised that prevents unconscious driving by emitting a warning sound and operating in the same manner as described above.

However, such a driving warning device can be constructed easily and inexpensively using an electronic circuit, and has the advantage that the driver does not have to worry about using the device because the driver only needs to respond by speaking in response to the warning sound. However, due to external noises other than the voice band such as power supply noise and engine noise, and external sounds in the voice band such as radio sounds and stereo sounds (hereinafter, these external noises and external sounds are collectively referred to as environmental sounds), the following may occur: The disadvantage was that malfunctions such as these occurred. In other words, now,
For example, suppose that a car equipped with the driving warning device is in a driving state and the driving warning device generates an alarm sound. As mentioned above, this warning sound continues until the driver utters a response voice, and because it continues, it is useful for preventing unconscious driving. However, in the driving warning device described above, after the warning sound is generated,
If the receiver receives high-level environmental sounds before the driver issues a response voice, a malfunction occurs in which the receiver stops generating the warning sound, assuming that the response voice has been received. In particular, if the above-mentioned malfunction occurs immediately after the warning sound is generated when the driver's consciousness is weakened, from the driver's perspective, it will be the same as if the warning sound had not been generated, resulting in poor reliability. .

The present invention was made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a highly reliable driving warning device that does not malfunction due to environmental sounds.

Embodiments of the present invention will be described below with reference to the drawings. The figure is a block diagram showing one embodiment of the driving warning device according to the present invention. In this figure, 1 is a periodic signal generator that periodically generates a signal V, and a variable resistor 1a controls the period T for 2 to 30 minutes, for example. It can be set to any time within the range. 2 is an alarm control circuit that outputs an alarm signal when the signal V is generated from the periodic signal generator 1; here, a flip-flop is set by the signal V and outputs an alarm signal until it is reset; 3 is a flip-flop 2;
This is an alarm circuit that generates an alarm sound in response to an alarm signal from the alarm signal oscillator circuit 3, which serves as a source of an intermittent beeping sound or an appropriate melody sound, for example.
a, gate circuits 3b and 3c, and a speaker 3d that emits an alarm sound. Reference numeral 4 denotes a voice detection circuit which receives a response voice such as "Okay ahead!" uttered by the driver in response to the warning sound, and outputs a signal F indicating that there has been a response to the warning sound. In this case, the voice detection circuit 4 includes a receiver 4a that receives the response voice, an amplifier circuit 4b that includes a gate that amplifies the voice input signal from the receiver 4a, and a voice detection circuit 4b that includes a receiver 4a that receives the response voice, an amplification circuit 4b that includes a gate that amplifies the voice input signal from the receiver 4a, and a voice detection circuit 4 that includes a receiver 4a that receives the response voice, an amplifier circuit 4b that includes a gate that amplifies the voice input signal from the receiver 4a, and a voice detection circuit 4b that includes a receiver 4b that includes a gate that amplifies the voice input signal from the receiver 4a. A filter 4c removes external noise signals and passes only the audio band. Out of the signals that have passed through the filter 4c, external sound signals in the audio band, such as radio sounds and stereo sounds, are set by a variable resistor VR ₁ . A clipper 4d to be removed by comparison with the clipping voltage level, a confirmation circuit 4e to check the output of the clipper 4d, an integration circuit 4f to smooth the output of the clipper 4d, and an output voltage level of the integration circuit 4f set by a variable resistor VR ₂ . A comparison circuit 4g that compares the voltage level and outputs a signal F when the voltage level is higher than the set voltage level, and an output of the comparison circuit 4g, that is, an audio detection circuit 4
It consists of a confirmation circuit 4h that confirms the output.
The integrating circuit 4f has an output time constant of several seconds, and this output time constant is determined by the variable resistor VR ₂
It is determined by adjusting. That is, by adjusting the variable resistor VR _2, the response voice utterance time (the time during which the response voice must be continuously uttered in order to output the signal F from the voice detection circuit 4) is determined.

5 is an OR circuit provided as necessary between the output terminal of the audio detection circuit 4 and the reset terminal of the flip-flop 2, and when the external switch 6 is closed, the signal F is not output from the audio detection circuit 4. The flip-flop 2 is provided so that it can be reset at any time. 7 has its output directly connected to the gate of the gate circuit 3c of the alarm circuit 3, and the amplifier circuit 4b of the voice detection circuit 4.
A time division circuit connected to the gate of
The signal path is opened and closed at high speed in a time-division manner (α/2), and while the warning sound generation and sound detection appear to be occurring in parallel to the driver, the warning sound is transmitted to the sound detection circuit 4. This prevents the signal from being input to the signal path and prevents false alarm sound detection from occurring.

Next, the operation of the above-mentioned inventive device will be explained. Now, for example, while driving a car, the variable resistor 1a
When the periodic signal generator 1 whose signal generation period T is arbitrarily set is operated, a signal V is generated according to the period T. When the signal V is generated, the flip-flop 2 is set and an alarm signal is sent to the alarm circuit 3, and an alarm sound is generated from the speaker 3d, thereby calling the driver's attention. When the driver hears the warning sound, he/she responds by saying, for example, "Okay ahead!". The voice detection circuit 4 receiving this response voice outputs a signal F indicating that there has been a response to the alarm tone. This signal F is sent to the reset terminal of flip-flop 2 via OR circuit 5, which resets flip-flop 2 and stops the operation of alarm circuit 3 (alarm sound generation). This prevents driving.

The above is a general description of the operation when the receiver 4a receives only the response voice, but in reality, in addition to the response voice, the receiver 4a also receives environmental sounds such as engine noise and radio sounds. The operation in such a case will be described below. That is, assume that the alarm circuit 3 now generates an alarm sound. At this time, if the driver responds, the receiver 4a receives the response voice, but also receives the environmental sound. The input signal from the receiver 4a is first amplified by the amplifier 4b and then sent to the filter 4c. The filter 4c removes external noise signals other than the voice band, such as engine noise, from the input signal and passes only the voice band.The passed signal is then sent to the clipper 4d. The clipper 4d removes external sound signals in the audio band such as radio sounds. Here, Clippa 4d
The clip voltage level is checked by variable resistor VR ₁ so that it will not malfunction due to external sound signals in the audio band such as radio sounds and stereo sounds, and will operate when a response voice is input. It is adjusted in advance while looking at the circuit 4e.

The output signal of the clipper 4d is smoothed by an integrating circuit 4f and then supplied to a comparator circuit 4g, which determines whether the supplied signal is equal to or higher than a voltage level set in advance by a variable resistor VR ₂ . If it is determined that the alarm is caused by a response voice (above the set voltage level), it outputs a signal F, and operates in the same manner as described above to stop the generation of the alarm sound.

As described above, the time division circuit 7 and the inverter 8 alternately open and close the signal path of the alarm circuit 3 and the signal path of the audio detection circuit 4 at high speed, so that the alarm sound is transmitted to the signal path of the audio detection circuit 4. It operates to prevent input.

As described above, according to the present invention, the voice detection circuit 4 is configured to include the filter 4c that removes external noise signals outside the voice band, and the clipper 4d that removes external sound signals in the voice band. To provide a highly reliable driving warning device that eliminates a malfunction in which even if external noise or external sound (environmental sound) is received, this is received as a driver's response voice and the generation of a warning sound is stopped. I can do it.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of the driving warning device according to the present invention. 1... Periodic signal generator, 2... Flip-flop (alarm control circuit), 3... Alarm circuit, 4...
Voice detection circuit, 4c...filter, 4d...clipper, 4g...comparison circuit, 7...time division circuit.

Claims (1)

[Scope of Claims] 1. A periodic signal generator that generates a signal at a predetermined period, an alarm control circuit that outputs an alarm signal based on the signal generation of the periodic signal generator, and an alarm from the alarm control circuit. an alarm circuit that generates an alarm sound in response to a signal; and an alarm control circuit that receives a response sound to the alarm sound and outputs a signal to the alarm control circuit;
In a driving warning device comprising a voice detection circuit for stopping the generation of the alarm sound, the voice detection circuit is combined with a filter for removing external noise signals outside the voice band, and a filter for removing external noise signals in the voice band. A driving warning device comprising a clipper. 2. The driving warning device according to claim 1, wherein the signal path of the warning circuit and the signal path of the audio detection circuit are opened and closed in a time-sharing manner. 3. The voice detection circuit compares the voltage level proportional to the volume of the received voice during a predetermined period of time with a voltage level arbitrarily set in advance, and when the voltage level proportional to the volume of the voice exceeds the set voltage level, the alarm control circuit is activated. The driving warning device according to claim 1 or 2, comprising a comparison circuit that outputs a signal to the vehicle.