KR20060054805A - Apparatus of drowsiness detection while driving based on non-constrained respiration measurement - Google Patents

Abstract

The present invention relates to an apparatus for detecting sleepless breath-based drowsiness driving, comprising: pressure change detecting means installed on a seat and / or seat belt of a driver to detect a minute pressure change applied due to breathing of a driver; A pressure sensor for detecting a pressure change of the pressure change detecting means and converting the pressure change means into an electrical signal; An A / D converter converting the output signal of the pressure sensor into a digital signal; Based on the pattern information of the breathing signal when drowsiness revealed in sleep medicine from the output of the A / D converter is configured to include a control unit to determine whether the drowsiness of the driver to warn through the warning unit when the drowsiness of the driver, the present invention is The driver's drowsy driving can be detected in a restrained state, thereby increasing convenience and economical since it is not necessary to use an expensive camera and image processing apparatus.

Breathing, Drowsiness, Detection, Air Cell, Pressure Sensor

Description

 {APPARATUS OF DROWSINESS DETECTION WHILE DRIVING BASED ON NON-CONSTRAINED RESPIRATION MEASUREMENT}             

1 is a block diagram of an apparatus for detecting drowsiness driving based on unrestrained breathing measurement according to an exemplary embodiment of the present invention.

2 is an operational flowchart of FIG.

3 is a block diagram of an apparatus for detecting drowsiness driving based on unrestrained breathing according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

10 air cell 20 pressure sensor

30,50,100: filter 40: acceleration sensor

60: A / D converter 70: control unit

80: warning unit 90: displacement sensor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting drowsiness driving. In particular, when a person breathes while sitting in a chair, such as driving a vehicle, a slight pressure change occurring in the direction of the chair bottom and the chair back, or a seat belt worn while driving and the driver's chest And an unrestrained breathing measurement-based drowsiness driving detection device capable of detecting drowsiness driving by measuring and analyzing a change in minute volume and pressure generated between the abdomen and measuring a breathing signal.

Recently, with the functional development of automobiles, the development of driver assistance systems has been actively progressed.

For example, an automatic navigation system that reduces the outbreak of a large traffic accident that occurs over a center line by configuring a sensing device capable of color identification in a vehicle so that the vehicle can proceed at a predetermined speed with a predetermined distance difference along the center line. To use the GPS system to identify the location of the current vehicle and input the coordinates of the destination so that the route from the current location to the desired destination can be displayed. Device to warn the driver by receiving a detection signal from a sensing device such as an ultrasonic sensor when driving backward or when driving, or to allow the vehicle brake system to operate, or to control the throttle valve of the electronic fuel injection device of the engine to reduce the vehicle speed Development of driving support system The.

In particular, as the driver's drowsiness may lead to a fatal accident, various devices have been proposed to detect the driver's drowsiness and alert the driver to prevent an accident caused by drowsiness.

Conventional techniques for detecting drowsy driving include a method of detecting an external environment, a method of detecting a vehicle operation state, a method of detecting drowsiness by processing an image of a driver, and a method of estimating drowsiness by analyzing other biological signals. There is this.

The method of detecting the external environment is a method of estimating drowsy driving by detecting a distance between cars or a white lane, for example, Korean Patent Application No. 1996-34714, which is caused by various vehicle driving environments. In the case of night driving, where detection failure and drowsy driving occur frequently, it is not effective and thus has a disadvantage in practicality.

The method of estimating drowsiness by detecting the vehicle operation state is to detect a hand brake, an accelerator, a coolant temperature, and the like, and to determine the drowsiness of the driver based on this. For example, Korean Patent Application No. 1997-29144 In addition, since the physiological phenomenon of drowsiness is not directly measured, a lot of errors occur and thus the accuracy is low.

In addition, a method of detecting the driver's image and estimating drowsiness based on the image is to determine the drowsiness based on photographing the eyelids, eyes, and head movements of the driver, for example, Korean Patent Application No. 1997-69813 For example, the camera may be installed at an arbitrary position of the vehicle to detect a face image of a driver in a driver's seat and analyze the driver's face according to the driver's eyes opening and closing rate, that is, the degree of blinking of the eyes. To judge.

As described above, the method of detecting the driver's image and following the drowsiness is evaluated as the most realistic among the prior arts, but it is often not detected in the actual driving environment due to shooting in the dark. In addition, expensive imaging and analysis software is a disadvantage.

Next, a method of estimating drowsiness by analyzing other biosignals is a method of estimating drowsiness by analyzing electroencephalogram, electrocardiogram, handle grip force, and the like, for example, Korean Patent Application No. 1996-16288. It is to detect the drowsiness state of the driver by continuously detecting the brain wave state of the driver, and the method of determining the drowsiness by analyzing the bio-signal as described above is disadvantage that the convenience is inferior as the electrode can be attached to the driver and the wires are stretched. There was this.

The present invention has been proposed to solve the problems of the prior art, the object of the present invention is to install the air cell on the inner surface of the seat belt or the place pressed by the weight of the driver to measure the pressure signal generated in the air cell when breathing Accordingly, the present invention provides a device for detecting drowsiness driving based on unrestrained breathing, which can detect drowsiness driving.

Another object of the present invention is to provide an apparatus for detecting drowsiness driving based on unrestrained breathing measurement to detect drowsiness driving of a driver based on the measurement of a change in the length of a seat belt.

In order to achieve the object of the present invention, the unrestrained breathing measurement-based drowsiness driving detection device of the present invention is installed in the driver's seat and / or seat belts for detecting a minute pressure change caused by the driver's breathing Change detection means; A pressure sensor for detecting a pressure change of the pressure change detecting means and converting the pressure change means into an electrical signal; An A / D converter converting the output signal of the pressure sensor into a digital signal; And a control unit for determining whether the driver is drowsy based on the pattern information of the breathing signal during sleepiness from the output of the A / D converter and warning through the warning unit during the drowsiness of the driver.

In order to achieve the another object of the present invention, the unrestrained breathing measurement-based drowsiness driving detection device of the present invention is installed in the driver's seat and / or seat belts for detecting a minute pressure change caused by the driver's breathing Pressure change detection means; A pressure sensor for detecting a pressure change of the pressure change detecting means and converting the pressure change means into an electrical signal; A displacement sensor for detecting a change in the length of the seat belt of the driver; An A / D converter for converting the output signals of the pressure sensor and the displacement sensor into digital signals; And a control unit for determining whether the driver is drowsy based on the pattern information of the breathing signal during sleepiness from the output of the A / D converter and warning through the warning unit during the drowsiness of the driver.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are merely to illustrate the present invention is not limited to the contents of the present invention.

Respiration is a typical mechanical movement in the human body with a heartbeat. During respiration, the volume changes in the rib cage and abdomen, and when you sit or lie down on an air cell with your weight, it is transmitted as a change in pressure inside the air cell. By measuring the pressure signal it is possible to measure the respiratory signal.

In this measurement, the pressure change due to weight or movement is large, whereas the pressure change due to respiration is minute, so to measure the differential pressure of two or more air cells. Applying this principle to the driver's seat or the seat belt of the vehicle, it is possible to measure respiration in the unrestrained state without attaching any sensor or electrode to the driver, and the present invention can detect drowsiness of the driver based on this principle. It is.

1 is a block diagram of an apparatus for detecting drowsiness driving based on unrestrained breathing according to an exemplary embodiment of the present invention.

As shown, the air cell 10 is installed in the driver's seat for detecting a minute pressure change caused by the driver's breathing, and detects the pressure change of the air cell 10 and converts it into an electrical signal A pressure sensor 20, an amplifier AMP1 and a filter 30 for amplifying and filtering the output of the pressure sensor 20 are provided.

The air cell 10 is installed in the form of an air cell matrix on the driver's seat, in particular, the back portion or the bottom of the driver's hip, and may be installed on the inner side of the seat belt in addition to the driver's seat, and the filter 30 may be a pressure sensor. Noise in the output signal of (20) is removed.

In addition, an acceleration sensor 40 is provided at a specific part of the vehicle, for example, a driver's seat to detect the vibration of the vehicle, and the acceleration sensor 40 also has an amplifier AMP2 for amplifying and filtering its output. The filter 50 is connected. Here, the filters 30 and 50 are band pass filters BPF.

An output terminal of each filter 30, 50 is provided with an A / D converter 60 for converting the output of the filters 30, 50 into a digital signal, and the A / D converter 60 has an A / D converter ( The controller 70 is configured to determine whether the driver is drowsy from the output of the alarm 60 and alerts the driver through the warning unit 80 so that the drowsiness of the driving may run away.

The present invention configured as described above will be described with the flowchart of FIG.

First, in the present invention, as the air cell 10 is installed in the driver's seat, in particular, the back part or the bottom of the hip, the driver's back part or the hip part contacts the air cell 10 when the driver sits on the seat.

At this time, when a change occurs due to the breathing of the driver, the pressure of the air cell 10 changes slightly.

Therefore, the pneumatic pressure of the air cell 10 is converted into an electrical signal by the pressure sensor 20, and at this time, the pressure sensor 20 measures the pressure of the unit air cell 10 to output a corresponding electric signal or If necessary, the pressure difference between the other air cells is measured to output an electrical signal corresponding to the pressure difference, and in this case, the detection efficiency will be improved compared with the pressure measurement of the unit air cell 10.

The output signal of the pressure sensor 20 is amplified by the amplifier AMP1, the noise in the signal is removed through the filter 30, and then input to the A / D converter 60 to be converted into a digital signal to control the controller. 70 is input.

In addition, when the air cell 10 is also installed in the seat belt, the corresponding signal is input to the controller 70 as described above.

On the other hand, while driving the vehicle, a situation may occur that makes it difficult to measure breathing as additional changes (Artifacts) may occur in addition to the change caused by the driver's breath in the air cell 10 due to the vehicle vibration.

Therefore, in the present invention, by using the acceleration sensor 40 to measure the vibration signal of the vehicle to remove the noise caused by the vehicle vibration.

That is, after the output signal of the acceleration sensor 40 is amplified through the amplifier AMP2 like the output signal of the pressure sensor 20, the noise in the signal is removed through the filter 50, and then A / D When the inputted to the converter 60 is converted into a digital signal and input to the controller 70, the controller 70 outputs the output of the air cell 20 and the output of the acceleration sensor 40 before determining whether the driver is drowsy. In comparison, the noise caused by the vehicle vibration is removed so that only the breathing signal by the driver's breath can be used for the determination of drowsy driving (steps S10 to S30).

On the other hand, the section of the driver's movement will not be able to detect the breathing signal because the pressure change is severely measured, but this movement indicates the awakening state rather than the driver's drowsiness. Can't.

As such, after removing the noise caused by the vehicle vibration, it is determined whether the driver is drowsy by comparing with the pattern of the breathing signal during the drowsiness found in the sleep medicine (step S40). To this end, the control unit 70 stores the pattern information of the breathing signal during sleepiness, which is found in sleep medicine, so that the control unit 70 determines whether or not sleepiness by using this.

If it is determined that the current situation is the drowsiness of the driver, the control unit 70 warns it through the warning unit 80 so that the drowsiness of the driver may run away (step S50, step S60). The pattern of respiratory signals during drowsiness revealed in the sleep medicine is a value indicating the relative specific gravity of the respiratory rate (= increased respiratory cycle), the increased periodicity of the respiratory rate, the severity breathing and the double breathing (TA Index) in the sleeping phase, the time to enter the sleep It is known that changes in the breathing pattern such as an increase (increase in the proportion of thoracic breathing) occur.

The warning unit 80 may generate a warning sound or vibration, or generate a cold wind or the like so that the driver's drowsiness may run away.

One embodiment of the present invention as described above is installed on the driver's seat, in particular the back portion or the bottom of the hip and the inner side of the seat belt of the driver by installing the air cell 10 to determine whether the driver is drowsiness based on the minute pressure change thereof To alert you.

3 is a block diagram of an apparatus for detecting drowsiness driving based on unrestrained breathing according to another embodiment of the present invention.

As shown, a displacement sensor 90, such as a strain gauge for detecting a change in the seat belt length, is further configured as compared to the above embodiment, and amplifies and filters the output of the displacement sensor 90. The amplifier AMP3 and the filter 100 are comprised.

In another embodiment of the present invention, the electrical signal corresponding to the minute pressure change of the air cell 10 and the output signal of the acceleration sensor 40 are respectively output to the controller 70 in the same manner as the above embodiment. Is converted into a digital signal and input.

After the length change detection signal of the seat belt by the displacement sensor 90 is input to the A / D converter 60 through the amplifier AMP3 and the filter 100 and converted into a digital signal, the signal is input to the controller 70. do.

Accordingly, the controller 70 removes noise due to vehicle vibration in the output signal of the air cell 10 by comparing the output of the air cell 10 with the output of the acceleration sensor 40 as in the above-described embodiment.

Subsequently, the controller 70 determines whether the driver is drowsy by comparing the pattern of the breathing signal when the drowsiness is found in sleep medicine. In this case, according to another embodiment of the present invention, the displacement sensor 90 is provided to determine whether the driver is drowsy in consideration of both the pressure change of the air cell 10 and the change of the length of the seat belt. Is the same as the above embodiment, the detailed description is weak.

Another embodiment of the present invention is to install the air cell 10 in the driver's seat, in particular the back portion or the bottom of the buttocks and the inner side of the seat belt of the driver to detect the minute pressure change of the cell 10, the displacement The sensor 90 detects the change in the length of the seat belt and compares it with the pattern of the breathing signal during the drowsiness found in the sleep medicine to determine whether the driver is drowsy and alert.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below Or it may be modified.

As described above, the unrestrained breathing measurement-based drowsiness driving detection apparatus according to the present invention detects and warns a drowsy driving of a driver, thereby preventing drowsy driving which is a major cause of a large traffic accident, thereby reducing traffic accidents. Compared to the drowsy driving detection method, the biosignal is directly measured in terms of reliability, and it is economical because it does not require expensive cameras and image processing devices.

In addition, if the air cells are arranged in a bed matrix manner, they can be placed under an incubator or intensive care unit to measure the patient's breathing signal in a completely unconstrained state. It is inconvenient to monitor in the state, but the convenience is increased because it is measured in the unrestrained state.

In addition, the home health monitoring device, which has attracted a lot of attention due to the development of communication technology and the progress of an aging society, should be able to be used to analyze breathing patterns during sleep.

Claims (12)

Pressure change detection means installed on the driver's seat and / or seat belt to detect minute pressure changes applied by the driver's breath; A pressure sensor for detecting a pressure change of the pressure change detecting means and converting the pressure change means into an electrical signal; An A / D converter converting the output signal of the pressure sensor into a digital signal; Unrestrained breathing measurement characterized in that it comprises a control unit to determine whether the drowsiness of the driver based on the pattern information of the breathing signal when drowsiness revealed in the sleep medicine from the output of the A / D converter to warn through the warning unit during the drowsiness of the driver Based drowsiness driving detection device. 2. The apparatus of claim 1, wherein the pressure change detecting means is an air cell. The apparatus of claim 2, wherein the air cell is in an air cell matrix form and is installed at the back of the driver's seat and the bottom of the hip. The apparatus of claim 3, wherein the pressure sensor detects a pressure change of a unit air cell or detects a pressure difference between the air cells. 5. The apparatus of claim 1, further comprising an acceleration sensor capable of sensing a vibration of the vehicle. The apparatus of claim 5, wherein the controller determines whether the driver is sleepy by removing noise due to vibration of the vehicle on the basis of the output of the acceleration sensor. Pressure change detection means installed on the driver's seat and / or seat belt to detect minute pressure changes applied by the driver's breath; A pressure sensor for detecting a pressure change of the pressure change detecting means and converting the pressure change means into an electrical signal; A displacement sensor for detecting a change in the length of the seat belt of the driver; An A / D converter for converting the output signals of the pressure sensor and the displacement sensor into digital signals; Unrestrained breathing measurement characterized in that it comprises a control unit to determine whether the drowsiness of the driver based on the pattern information of the breathing signal when drowsiness revealed in the sleep medicine from the output of the A / D converter to warn through the warning unit during the drowsiness of the driver Based drowsiness driving detection device. 8. The apparatus of claim 7, wherein the pressure change detecting means is an air cell. 10. The apparatus of claim 8, wherein the air cell is in the form of an air cell matrix and is installed at the back of the driver's seat and the bottom of the hip. The apparatus of claim 7, further comprising an acceleration sensor capable of detecting a vibration of the vehicle. 9. The apparatus of claim 10, wherein the controller is configured to determine whether the driver is sleepy by removing noise due to vibration of a vehicle in consideration of the output of the acceleration sensor. 8. The apparatus of claim 7, wherein the displacement sensor is a strain gauge.

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