JP4054905B2 - EEG braking device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention is intended to automatically apply the brakes and engine brakes of a vehicle by brain waves.
[0002]
[Prior art]
Japanese Utility Model Publication No. 5-30796 uses a brain wave to detect a driver's sleep and to prevent the sleep by lighting. Similarly, a device that emits a warning sound has been proposed.
Japanese Patent Laid-Open No. 62-71727 discloses a mechanism for automatically braking according to the inter-vehicle distance.
In US Pat. No. 5,492,394, it is mentioned a little that the brakes are applied by the electroencephalogram.
US Pat. No. 4,949,726 proposes a mechanism for moving a toy according to an electroencephalogram pattern.
[0003]
[Problems to be solved by the invention]
If the driver is awake, it can be said that there is almost no need for automatic braking at the distance between the vehicles. Near intersections, there is often no inter-vehicle distance. Therefore, Japanese Patent Application Laid-Open No. Sho 62-71727 seems to be effective when the driver is running silently or sideways. During the driver's idle driving, the vehicle may travel in an undesired direction and the inter-vehicle distance may not be accurately measured, and the automatic braking may not be performed appropriately.
When you are drowsy, you may fall asleep even in a bright place or at a very high volume of the radio. In this sense, Japanese Utility Model Publication No. 5-30796 is insufficient.
US Pat. No. 5,492,394 does not disclose the relationship between snoring and brain waves, and does not disclose under what conditions the brain waves are judged to be snoring and applying automatic braking.
U.S. Pat. No. 4,949,726 is probably the closest prior art,
As in the present invention, when “living”, that is, when consciousness is disappearing,
Or, instead of detecting the brain wave after it disappears and automatically applying the brakes, you can use the brain wave at the time of awakening, move the toy with the brain wave "consciously" without using the limbs The brake is intended to be applied and is different from the present invention.
US Pat. No. 4,949,726 does not mention the δ wave during sleep.
Also, we are discussing how to move and stop toys using registered brain wave patterns, but it would be difficult to safely obtain the brain wave pattern during sleep driving in advance. Moreover, the method is not disclosed.
If you are dealing with a state of complete sleep, the brain wave pattern when sleeping in a bed (which is easy to obtain) may be the same as the brain wave pattern during sleep on the car, This area is outside the handling range of US Pat. Moreover, even if this prior art can be used, the car will cause an accident during that time, because it will stay at least 10 seconds or several seconds before falling into sleep. Therefore, it has no meaning.
Also, it is impossible to discuss the identity of the EEG spectrum and EEG pattern when sleeping on a bed and when driving.
Considering the subtle differences between the two and the brain waves of individuals and individuals, it is different from simply moving or stopping toys, and preventing accidents while driving. Is it possible to register and use the EEG pattern of bed rest on the bed for judgment of bed rest?
Is it possible to obtain brain wave patterns during sleep driving? The time when it was acquired is the time when the accident is about to occur.
In the present invention, the above-described problem is overcome by feeding back the user's comfort parameters to the system by the user himself / herself.
[0004]
[Means for Solving the Problems]
Electroencephalogram input means 1,
A brain wave analysis means 2 for analyzing a theta wave indicating a state in which a person is going to sleep from the brain wave and a delta wave that appears when the person is already sleeping;
The vehicle is composed of automatic braking means 3 for automatically braking the vehicle.
[0005]
[Action]
An electroencephalogram of the driver of the vehicle is taken into the system by the electroencephalogram input means 1, and the electroencephalogram is analyzed by the electroencephalogram analysis means 2,
Theta waves, delta waves, or brain waves in between are detected,
When it satisfies a predetermined condition, the automatic braking means 3 is activated and the vehicle is automatically engine braked or braked.
[0006]
When the proportion of the θ wave increases with respect to the whole brain wave, the engine brake is automatically applied,
When the ratio of the integrated value of θ wave and δ wave in the whole brain wave increases, half brake is automatically applied,
Full braking may be automatically applied when the ratio of δ waves in the entire brain wave increases.
[0007]
【Example】
As the electroencephalogram input means 1, an electroencephalograph can be used.
The electroencephalogram analysis means 2 is composed of an amplifier 6, a band pass filter 7, an A / D converter 8, and a computer 9 or a microprocessor 9.
As the computer 9 shown in FIG. 9, a vehicle-mounted computer <for control for other purposes> and a microprocessor can be used. <If there is enough room for processing capacity. >
From the viewpoint of improving the processing speed, a computer dedicated to the electroencephalogram analysis means 2 is installed, and the analysis result obtained by the computer is transferred to an existing microprocessor for control, from which the automatic braking means 3 is instructed again. May be transferred.
Among the electroencephalograms, δ waves appear during sleep and are 0.5 to 3.5 Hz.
The θ wave appears when you begin to sleep and is between 3.5 and 7.5 Hz.
The frequency band of the above δ and θ waves may change slightly in the future as brain medicine advances.
In addition, it is known that there are α waves and β waves that appear at awakening.
An excellent example of the automatic braking means 3 for a vehicle is disclosed in Japanese Patent Application Laid-Open No. Sho 62-71727 <gazette p156, lower right column, seventh row to p157, upper right column fifth row>. US Pat. No. 5,492,394 is a fine example as a simple automatic braking means.
[0008]
An excellent prior art that integrates the electroencephalogram input means 1 and the pioneering electroencephalogram analysis means is HAL <Hemisphere Activation Level.
It is known as Detector>. Steve Cearcia
<Jully 1988, “BYTE”, Computers On the Brain> Here, the system is meaningful, and the characteristic part of the electroencephalogram analysis means 2, that is, the user's comfort parameters are fed back to the system by the user himself / herself. The following describes the procedure for improving the accuracy of sleep judgment using this system.
The input brain wave is subjected to fast Fourier transform (a dedicated program is widely used), and its frequency component can be obtained. Let the frequency distribution be B (f).
Here, f is the frequency of the electroencephalogram, and B (f) is the intensity of the electroencephalogram and the amplitude of the electroencephalogram signal. The signal intensity of the so-called θ wave and δ wave is obtained by integrating this in the frequency band of the θ wave and δ wave.
Based on these, δp in FIG. 2 and θp in FIG. 3 are obtained.
Here, the denominators in FIGS. 2 and 3 are the integrated values of the electroencephalogram signal with respect to all the frequency components <0.5 to 30.5 Hz> of the electroencephalogram. The numerator in FIG. 2 is an integral value of a δ wave electroencephalogram signal. The numerator in FIG. 3 is an electroencephalogram signal integration value of the θ wave.
δp is the ratio of δ waves in all components of the electroencephalogram,
θp is a ratio occupied by θ waves in all components of the electroencephalogram.
[0009]
Together with δp and θp, δp ′ and θp ′ in FIGS. 4 and 5 can be used.
4 and 5, max (δ) is the maximum value of the signal component of the δ wave.
max (θ) is the maximum value of the signal component of the θ wave.
max (α) is the maximum value of the signal component of the α wave <7.5 to 13.5 Hz>.
max (β) is the maximum value of the signal component of the β wave <13.5 to 30.5 Hz>.
δp ′ is a person representing the ratio of δ waves, focusing only on the maximum value of each signal component of δ wave, θ wave, α wave, and β wave. Similarly, θp ′ is the ratio of θ wave Is expressed. In the above, we have described two methods that represent the ratio of δ and θ waves to the total brain wave components. However, in addition to these methods, the ratio of δ and θ waves to the total brain waves is more appropriate. If a simple calculation formula is discovered by the advancement of brain medicine, it is not difficult to incorporate it as software.
[0010]
The above analysis procedure is implemented in software in the computer 9 of the electroencephalogram analysis means 2 and is calculated, for example, in units of 10 ms. <If the speed is 60 km / h, the speed advances 17 cm in 10 ms for about 17 m / s per second. 10 ms is a small value in terms of temporal changes in brain waves, and as long as the road is straight, it will be sufficient from the point of speed control of the car body. Of course, considering traveling on an expressway, the calculation time of each ratio is better as it is shorter, and may be in units of 5 ms. Fortunately, from a practical point of view, microprocessors are becoming increasingly faster and cheaper. _>
Thus, θp, δp, αp, βp and θp ′, δp′αp ′, βp ′ are calculated.
If the θ wave becomes stronger than other components of the electroencephalogram, for example, it is highly possible that θp> 0.7 starts to stay. Therefore, the engine brake is applied while announcing that fact. This announcement is reproduced by the instruction of the computer 9 of the electroencephalogram analysis means 2 registered in the tape recorder or the semiconductor IC. This can be easily implemented in software.
Engine braking is performed by transmitting an instruction from the computer 9 of the electroencephalogram analysis means 2 to the automatic braking means 3.
Here, a numerical value of 0.7 is used, but if the driver feels that the announcement has been made, that is, the timing for automatically applying the engine brake is too early, the driver can use the keyboard on the instrument panel to do this. Can be changed to 0.8, for example.
On the contrary, if it is felt that the announcement and automatic braking are slow, as an example, 0.6 may be input.
In this way, the user can cause the computer 9, that is, the electroencephalogram analysis means 2 to use the optimum value according to each person's constitution.
[0011]
Similarly, when θp ′> 0.7, there is a possibility that he / she has started to sleep, so the engine brake is applied while announcing that.
If the user determines that it is more effective to use θp ′ as a detection procedure for snoring than using θp, 1 is input instead of 0.7 where θp> 0.7. Then, θp> 1 cannot occur, so this condition is ignored by the system.
[0012]
If the θ wave and δ wave components become stronger than other α waves and β waves, for example, if θp + δp> 0.7, there is a high possibility that pioneering has progressed. While making a little loud announcement, apply the half brake to a slightly higher brake hydraulic pressure. At the same time, turn on the brake lamp. In either case, the computer 9 of the electroencephalogram analysis means 2 issues an instruction to <each about the brake to the automatic braking means 3>.
If the user is using and feels that the automatic braking is too early, 0.7 may be corrected to 0.8 as an example.
Also, if you feel that this automatic braking is too slow, you can correct this to 0.7 as an example.
[0013]
Even when θp ′ + δp ′> 0.7, there is a high possibility that the state of craving has advanced, so that half-brake is applied while announcing at a somewhat loud volume. At the same time, turn on the brake lamp.
However, if it is determined that θp + δp> 0.7 is superior to θp ′ + δp ′> 0.7 as a detection of a state in which the user is using the system, and θp ′ + δp is greater than θp ′ + δp If “> 1.0” is specified from the keyboard, <this is not possible in nature> Thereafter, only θp + δp> 0.7 is effective for this system.
[0014]
If the ratio of δ waves to other α waves, β waves, and θ waves increases, as an example, if δp> 0.7, there is a high possibility that a complete stagnation has occurred. Or, apply a full brake, such as a sudden brake, while making an announcement to that effect at an oversized volume. At the same time, turn on the brake lamp. In either case, the computer 9 of the electroencephalogram analysis means 2 issues this to each by issuing an instruction <for brakes to the automatic braking means 3>.
If you are wearing a balloon-shaped shock absorber, you may preliminarily partially inflate it about halfway. Further, at night, all the room lights may be turned on for the convenience of the following vehicle.
If the user is using and feels that the timing of this sudden braking is too early, 0.8 may be changed and input as an example instead of 0.7.
If you feel that the timing of this sudden braking is too late, you can enter 0.6 as an example.
[0015]
Similarly, when δp ′> 0.7, there is a high possibility that the person has fallen into a complete state of stagnation, so that the full brake is applied while making a loud announcement.
If it is determined that using δp is more effective than using δp 'as a means of detecting that the user has completely fallen into craving, instead of 0.7, δp'> 0.7. You can enter 1.0 into.
In addition, if the subject moves his / her body during EEG measurement, it will affect the measurement, but this system starts to crawl up to complete craving, so the above There is little room for problems, and it will be possible to accurately amplify the very low frequency components of the brain waves.
[0016]
FIG. 6 is an example of the control parameter input screen.
Underlined parts indicate items that can be input. “Volume” indicates the volume of the announcement volume in each case, and these can be changed and input.
Such a screen can be easily realized by BASIC or Visual Basic. The input value is used by the electroencephalogram analysis means 2 as described above.
[0017]
An example of the automatic braking means 3 is shown in FIGS.
In order to generate the braking force by the engine brake, a drive signal is issued to the throttle actuator 12 and the second throttle valve 14 is controlled to be closed.
Further, in order to obtain the braking force by the half brake and the full brake, the corresponding half brake and full brake drive signals are output to the brake actuator 42.
Note that in the frequency band of the θ wave and δ wave, it can be said that the lower the brain wave frequency, the greater the depth of sleep. Therefore, instead of the integral value ratios δp and θp, the peak value ratio, θp When adopting ', δp' in this system,
When applying half-brake, the peak value of the θ wave and δ wave is given and the average value of each frequency is inversely proportional to the brake oil pressure. When full braking is applied, it is also possible to apply brakes at a lower brake hydraulic pressure at frequencies that are more biased toward the θ wave.
[0018]
Even when the ratios δp and θp of the integrated values are adopted, the same can be done by obtaining an effective average value corresponding to the average value of both frequencies that gives the above peak value.
[0019]
In FIG. 6, when none of the conditions defined by the user is satisfied, that is, when the system determines that the user has woken up, the output of drive signals to the throttle actuator 12 and the brake actuator 42 At the same time, the system automatically cancels the automatic braking. In JP-A-62-71727, the automatic braking is released by depressing the brake pedal. However, in this system, when the ratio of α waves and β waves to the whole brain waves increases, the automatic braking is released. Is done.
[0020]
【The invention's effect】
When the driver is idle, the vehicle is automatically braked, so there is a possibility of stopping the vehicle safely.
Moreover, even if some kind of collision accident occurs due to craving, the deceleration effect of the present system can reduce the impact at the time of the collision, and the possibility that the degree of the accident will be reduced increases.
The same effect can be expected when the driver falls into heart disease while driving and becomes unconscious.
It should be noted that the present invention can be used to safely acquire an electroencephalogram spectrum when staying while driving, not on a bed. For this purpose, the electroencephalogram pattern at the time when the automatic braking of the present system is activated is written on the disk <not shown> of the computer 9 <with time>. This can be easily realized by the computer 9.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of the system. FIG. 2 is a calculation formula for obtaining a δ wave ratio from an integral value. FIG. 3 is a calculation formula for obtaining a θ wave ratio from an integral value. A calculation formula for determining the ratio of δ waves by the maximum value.
See also explanatory text in FIG.
FIG. 5 is a calculation formula for obtaining the θ wave ratio based on the maximum value. FIG. 6 is an example of an input screen for providing a reference value for automatically performing engine braking, half braking, and full braking. The schematic block diagram of the automatic braking means 3. FIG.
The parts related to braking caused by the brake pedal are excluded.
FIG. 8 is a block diagram of the present system expressing the automatic braking means 3 in some detail. FIG. 9 is a block diagram of the electroencephalogram analysis means 2.
1 is an electroencephalogram input means 2 is an electroencephalogram analysis means 3 is an automatic braking means 6 is an amplifier 7 is a bandpass filter 8 is an A / D converter 9 is a computer 12 is a throttle actuator 13 is a throttle link. 12 is driven.
14 is the second throttle valve. The intake air amount is adjusted by opening and closing at 13.
23 is a sub master cylinder. For generating brake oil pressure regardless of driver's brake pedal operation.
24 is a wheel 26 is a wheel cylinder provided on the wheel.
32 is a change valve. The brake hydraulic pressure generated at 23 is transmitted to 26, and includes a shuttle valve.
Reference numeral 40 denotes a pressure generation source 42 including a hydraulic pump and a reservoir, and a brake actuator. For driving the brake oil pressure by driving 23.

Claims (1)

A brain wave input means 1 for inputting a driver's brain wave, a theta wave indicating a state in which a person is going to sleep from the input brain wave , a delta wave that appears during human sleep , an alpha wave that is a brain wave at awakening, and An electroencephalogram analyzing means 2 for analyzing a beta wave and an automatic braking means 3 for a vehicle,
When the ratio of the alpha wave or beta wave to the whole brain wave is higher than the predetermined value , the automatic braking is released by issuing a brake releasing instruction from the electroencephalogram analyzing means 2 to the automatic braking means 3. , A brain wave braking device,
When the ratio of theta waves to the entire brain wave increases above a predetermined value, the engine brake instruction is automatically issued from the electroencephalogram analysis means 2 to the automatic braking means 3 to automatically apply the engine brake of the vehicle. Or
When the ratio of the integrated value of the theta wave and the delta wave to the whole electroencephalogram is higher than a predetermined value, a half brake instruction is issued from the electroencephalogram analysis means 2 to the automatic braking means 3, whereby the vehicle To automatically apply the half brake, or
When the ratio of the delta wave to the whole brain wave is higher than a predetermined value, the full brake command of the vehicle is automatically issued by issuing a full brake instruction from the electroencephalogram analysis means 2 to the automatic braking means 3. An electroencephalographic braking device that is applied to

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