JPH05330360A - Vehicle drowsiness prevention device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a vehicle doze prevention device for vibrating the driver's seat to prevent drowsiness, the driver is effectively awakened without causing discomfort to the driver. [Structure] A heartbeat sensor 100, a waveform processing circuit 102, and a determination device 104 determine whether or not a driver is dozing, and when a dozing occurrence is detected, a drive circuit 106 is detected.
The vibration unit 108 built in the driver's seat 1 is vibrated. At this time, the vibration frequency is set to 40 Hz to 50 Hz and the amplitude is set to 0.5 mm to 1.0 mm to vibrate, thereby shifting the resonance point of the body and awakening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drowsiness prevention device,
In particular, it relates to a device for vibrating the driver's seat to wake up when a drowsiness occurs.

[0002]

2. Description of the Related Art Conventionally, various safety devices have been proposed for the purpose of ensuring safety when the vehicle is running, and a drowsiness prevention device is one of them. Generally, with a drowsiness prevention device,
A configuration has been proposed in which the occurrence of drowsiness is detected from changes in steering and changes in the driver's heartbeat, and the driver is awakened by vibrating the driver's seat with a buzzer, lamp, or the like.

For example, the actual Kaihei 1-141 shown in FIG.
In No. 135, a vehicle in which a driving device 2 for vibrating the driver's seat 1 is provided in the driver's seat 1 and the driver's seat 1 is driven by the driving device 2 to directly stimulate the driver when the dozing detector 31 detects the dozing. A snooze prevention sheet is disclosed.

[0004]

However, the inventor of the present application cannot effectively awaken the driver by simply vibrating the driver's seat at an arbitrary frequency, and depending on the frequency, the driver's seat I found that there was a problem that the driver felt uncomfortable due to the vibrations, and in some cases caused physical problems. This is closely related to the natural resonance point of the driver's body, and it is considered that this is caused by causing adverse effects by vibrating at the resonance frequency of each part of the body.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to give a predetermined vibration to the driver's seat to effectively awaken the driver without causing the driver's discomfort.

[0006]

In order to achieve the above object, a vehicle dozing prevention device of the present invention sets a vibration frequency of a driver's seat by a drive device in a range of 40 Hz to 50 Hz, and the drive device. The vibration amplitude of the driver's seat is set in the range of 0.5 mm to 1.0 mm.

[0007]

As described above, paying attention to the fact that the driver may complain of a malfunction due to the vibration of the driver's seat, the inventor of the present application finds the driver's arousal level and discomfort when vibrating at various frequencies and amplitudes. The vibration frequency of 40Hz to 50Hz
In the range of 0.5 mm to 1.
It was found that the vibration can be shifted from the natural resonance point of the driver's body and effectively awakened by setting the range to 0 mm.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle dozing prevention device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall construction of a vehicle drowsiness prevention device of this embodiment. A heartbeat sensor 100 for detecting the heartbeat of the driver is provided in the driver's seat 1 and outputs the detected heartbeat to the waveform processing circuit 102 as an electric signal.
The waveform processing circuit 102 processes the heartbeat signal and outputs it to the determination device 104. The determination device 104 compares the input heartbeat signal (heart rate) with a predetermined threshold value and determines whether or not a nap is occurring. Then, when it is determined that the doze occurs, the drive circuit 106
Control signal is output to. The drive circuit 106 is configured to drive the vibrating unit 108 at a predetermined pulse current value and a pulse cycle, and vibrate the driver's seat 1 at a frequency and an amplitude described later.

FIG. 2 shows the structure of the vibration unit 108. The vibrating unit 108 is configured to include a leaf spring 108a and an electromagnet 108b, and the leaf spring 108a vibrates in response to a drive pulse from the drive circuit 106.
The vibration of a is transmitted to the driver's seat 1.

The characteristic feature of this embodiment is that the vibration frequency and amplitude of the driver's seat 1 are set in a predetermined range, that is, the frequency is set to 40 Hz to 50 Hz, and the amplitude is set to 0.5 mm to 1.0 mm. That is the setting. The significance and effects of this range will be described below.

Selection of Frequency FIG. 3 is a diagram showing the resonance part of the body and the transmission part of vibration for various frequencies. As shown in this figure, it is known that the human body has an inherent resonance point, and the abdomen and chest are from about 5 Hz to 10 Hz, and the head and eyes are from about 20 Hz to 30 Hz. There are resonance points in each. At these resonance points, each part resonates, and it is considered that there is some adverse effect. Therefore, the inventor of the present application has a plurality of test subjects (10 men and women, 18 years old-
45 years old) was examined by sitting on the driver's seat shown in FIG. 1 and applying various vibrations.

The results of the examination are shown in FIG. 4, where the horizontal axis represents the applied frequency, the vertical axis represents the degree of discomfort, and each plot represents the average of 10 test subjects. In the figure, it can be seen that the user feels unpleasant in the frequency range of about 3 Hz to 40 Hz, and matches well with the frequency band of the resonance point shown in FIG. In particular, at 3 Hz to 10 Hz in FIG. 4, the abdomen and chest feel uncomfortable.
It is understood that the ears feel uncomfortable at 0 Hz to 20 Hz, and the eyes vibrate at 20 Hz or higher, and the resonance points of each part of the body correspond to the discomfort. Therefore, it is understood that the frequency band needs to be several Hz or 40 Hz or more in order not to cause the driver to feel uncomfortable.

Further, FIG. 5 shows the results of measuring the applied frequency and the appearance rate of the α-wave of the electroencephalogram. The experiment was performed by having a test subject play a simple TV game and measuring the change over time of the α-wave when the test subject was vibrated at a predetermined frequency (3 Hz and 45 Hz) after becoming drowsy.
In the figure, the horizontal axis represents time and the vertical axis represents the α wave appearance rate (%), and the α wave appearance rate generally increases as the subject becomes sleepy. Therefore, it was determined that the subject became sleepy when the α wave appearance rate reached the maximum value α 0, and 3 Hz and 45 Hz
The driver's seat is vibrated at the frequency (amplitude is 1 mm). Then, the subject is awakened by this vibration, and the α wave appearance rate also decreases and changes to the minimum value α 1. Therefore, the rate of decrease of α-waves due to vibration, that is, the awakening degree is defined as the rate of decrease of α-waves (awakening degree) = (α0-α1) / α0 × 100
It was evaluated by [%].

FIG. 6 shows the average value and the standard deviation of the α wave lowering rate at frequencies of 3 Hz and 45 Hz. A large awakening effect is obtained at 45 Hz, while almost no awakening occurs at 3 Hz, and in some cases drowsiness occurs. You may feel strongly. As a result, it can be seen that the frequency band of 40 Hz or higher is suitable for causing the driver to be uncomfortable and effectively awakening. However, at a frequency of 50 Hz or higher, it is difficult to obtain an amplitude of about 1 mm due to the structure of the vibration unit, and there is a concern that the higher the frequency, the risk of damage to the blood circulation of the capillaries. Therefore, after all, a frequency of 40 Hz to 50 Hz is appropriate.

Selection of Amplitude In order to perform appropriate amplitude selection in the same manner as the above-described frequency selection, various amplitudes (0.2 mm, 0.5 mm, 1.0 mm in this embodiment) are set at 45 Hz when the subject becomes sleepy. The appearance rate of α-wave when given was measured, and the α-wave decrease rate at that time was calculated. The calculation result is shown in FIG. 7, where the horizontal axis represents the amplitude and the vertical axis represents the α-wave reduction rate. Α at an amplitude of 1 mm
It can be seen that the waves are greatly reduced, and a considerably great awakening effect is obtained. Further, it can be seen that the wakefulness effect is obtained even at 0.5 mm, but when it becomes 0.2 mm, the wakefulness effect is hardly obtained, and conversely, it may become more sleepy. As a result, it can be seen that an amplitude of 0.5 mm or more is effective for awakening, but if an amplitude of 1 mm or more is given, the vibration becomes too strong and discomfort occurs.
It is suitable to be 1.0 mm.

As described above, in this embodiment, the frequency is 40H.
z to 50 Hz, amplitude 0.5 mm to 1.0
By setting to mm, it is possible to wake up the driver extremely effectively without causing the driver to feel uncomfortable due to the vibration of the driver's seat.

In this embodiment, the amplitude is 0.2 mm.
On the contrary, it is found that the driver becomes drowsy at the time of driving. Therefore, in order to prevent the drowsiness during driving more effectively, the driver's seat is vibrated at 40 Hz to 50 Hz and the amplitude is about 0.2 mm during the rest while the driver is stopped. It is also possible to invite a good night's sleep.
Therefore, a changeover switch (having a step for switching between awakening and a break) is provided near the driver's seat to switch to a break during a break and vibrate the driver's seat by about 0.2 mm to sleep, and switch to awake while driving to sleep. By using a system that vibrates at 0.5 mm to 1.0 mm at the time of occurrence, further safe driving will be possible.

[0019]

As described above, according to the vehicle dozing prevention device of the present invention, the driver does not feel uncomfortable.
Moreover, it is possible to effectively wake up the driver and prevent drowsiness.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a vibration unit according to the embodiment.

FIG. 3 is a diagram showing a relationship between a frequency and a resonance point of a body.

FIG. 4 is a diagram showing a relationship between frequency and discomfort in the embodiment.

FIG. 5 is a diagram showing a relationship between a frequency and an α wave appearance rate in the embodiment.

FIG. 6 is a diagram showing a relationship between a frequency and an α-wave reduction rate in the example.

FIG. 7 is a diagram showing the relationship between the amplitude and the α-wave reduction rate in the same example.

FIG. 8 is a configuration diagram of a conventional device.

[Explanation of symbols]

 1 Driver's Seat 100 Heart Rate Sensor 102 Waveform Processing Circuit 104 Judgment Device 106 Drive Circuit 108 Vibration Unit

Claims (1)

[Claims] 1. A drowsiness prevention device for a vehicle, which detects the occurrence of drowsiness from the state of a vehicle driver and vibrates the driver's seat by a drive device to awaken the driver, wherein a vibration frequency of the driver's seat by the drive device is 40 Hz. To 50 Hz, and the vibration amplitude of the driver's seat by the drive device is set to a range of 0.5 mm to 1.0 mm.