WO2021002616A1 - Drunk driving prevention apparatus - Google Patents

Abstract

The present invention relates to a drunk driving prevention apparatus provided in a vehicle. The present invention comprises: a carbon dioxide sensor which includes a sample gas inlet pipe through which sample gas, which is gas exhaled by a driver mixed with air inside the vehicle, is introduced and a sample gas outlet pipe through which the introduced sample gas is discharged, and which generates an electric signal according to a concentration of carbon dioxide included in the sample gas introduced through the sample gas inlet pipe; a suction pump connected to the sample gas outlet pipe of the carbon dioxide sensor, and introducing the sample gas into the carbon dioxide sensor during operation; an exhaust pipe connected to an outlet of the suction pump; an alcohol sensor which generates an electric signal according to an alcohol concentration of the sample gas flowing through the exhaust pipe; and a controller configured to control a starting device of the vehicle by determining whether the driver is intoxicated on the basis of electrical signals from the carbon dioxide sensor and the alcohol sensor. The drunk driving prevention apparatus, according to the present invention, immediately checks whether the driver is intoxicated in a short time of about 3 seconds, when the driver boards the vehicle and blows the exhaled gas toward a steering wheel or a drunk driving prevention apparatus installed on a sun visor.

Description

Drunk driving prevention device

The present invention relates to an apparatus for preventing drunk driving provided in a vehicle.

Drunk driving is strictly restricted by law because it can cause fatal damage to not only the driver himself, but also others. However, since there is no device for preventing drunk driving in a general vehicle, even a driver in a drunk state can drive freely.

In order to solve this problem, recently, a drunk driving prevention device has been developed that measures the concentration of alcohol contained in the driver's exhaled gas and prevents the vehicle from starting when the concentration is higher than a reference value.

For example, Korean Patent Laid-Open Publication No. 10-2017-0040890 includes a sensor that measures an alcohol concentration and outputs the measured alcohol concentration; And a processor for controlling the vehicle by performing drunk driving authentication based on the alcohol concentration sensed through the sensor, wherein the processor includes a first drunk driving according to the alcohol concentration detected through the sensor before starting the vehicle Disclosed is a vehicle assistance apparatus for performing authentication and additionally performing secondary drinking driving authentication according to an alcohol concentration detected through the sensor while the vehicle is driving. The device of Korean Patent Application Publication No. 10-2017-0040890 can prepare for proxy authentication of acquaintances who have not been drunk through additional authentication while driving, or replacement of a driver while driving a vehicle.

In addition, Korean Patent Registration No. 10-1525204 includes an alcohol measurement unit that measures the alcohol concentration contained in the driver's exhalation, a recognition unit that recognizes authentication information set in advance to authenticate the driver, and a state collection that collects driver's state information inside the vehicle. A storage unit for storing authentication information and status information of the driver, suction position and pattern information when measuring alcohol consumption for each driver, and information transmitted from the alcohol measurement unit, recognition unit and state information collection unit, and information stored in the storage unit And a control unit that generates a control signal to control the starting of the vehicle by comparing the driver to authenticate the driver and to determine whether the driver is in a drunk state, and the authentication information includes image information photographing the driver and fingerprint information of the driver and the photographed image information. An apparatus for preventing drunk driving is disclosed, characterized in that it includes information on a suction position and a pattern when measuring a driver's alcohol consumption extracted by analyzing The drunk driving prevention device of Korean Patent Registration No. 10-1525204 also aims to prevent proxy authentication by a passenger or a passerby.

In addition, Korean Patent Laid-Open Publication No. 10-2016-0096251 determines whether the driver is drinking alcohol based on the measurement result of alcohol concentration in the indoor air of the vehicle, and generates a first alcohol warning signal when the driver is determined to be in a state of suspicion of drinking. A first drinking warning signal generator for; And when receiving the first drinking warning signal, determining whether the driver is drinking alcohol based on the result of measuring the driver's heart rate, and generating a second drinking warning signal when it is determined that the driver is drinking. A device for preventing drunk driving, characterized in that it comprises a second drinking warning signal generator for, is disclosed.

In addition, Korean Patent Registration 10-0706040 discloses a vehicle key capable of preventing drunk driving. The vehicle key disclosed in Korean Patent Registration No. 10-0706040 includes a controller, an insertion prevention means, an alcohol sensor, and a carbon dioxide sensor. The controller of the key detects carbon dioxide in the user's exhalation based on the output signal from the carbon dioxide sensor, and determines whether or not the user has exhaled. Further, the alcohol concentration in the user's exhalation is measured based on the output signal of the alcohol sensor, and the measured value and the reference value are compared. As a result of the comparison, if the alcohol concentration is higher than the reference value, the insertion preventing means protrudes to prevent the vehicle key from being inserted into the keyhole for starting the vehicle.

[Patent Literature]

Korean Patent Publication 10-2017-0040890

Korean Patent Registration 10-1525204

Korean Patent Publication 10-2016-0096251

Korean Patent Registration 10-0706040

An object of the present invention is to provide a device for preventing drunk driving with a new structure capable of quickly determining whether a driver is drinking alcohol.

In order to achieve the above object, the present invention includes a sample gas inlet pipe into which a sample gas mixed with an exhaled gas of a driver and air inside a vehicle is introduced and a sample gas outlet pipe through which the introduced sample gas is discharged. A carbon dioxide sensor for generating an electric signal according to the concentration of carbon dioxide contained in the sample gas introduced through the gas inlet pipe; A suction pump connected to the sample gas outlet pipe of the carbon dioxide sensor and for introducing a sample gas into the carbon dioxide sensor during operation; An exhaust pipe connected to an outlet of the suction pump; An alcohol sensor that generates an electric signal according to the alcohol concentration of the sample gas flowing through the exhaust pipe; And a controller configured to control the starting device of the vehicle by determining whether the vehicle is in a drinking state based on electrical signals from the carbon dioxide sensor and the alcohol sensor,

The controller determines a change value of the carbon dioxide concentration (Cc) in the sample gas for X seconds obtained by comparing the electric signal value of the current carbon dioxide sensor with the electric signal value of the carbon dioxide sensor before a predetermined X seconds. If the carbon dioxide concentration comparison unit comparing the carbon dioxide concentration change reference value Rc and the carbon dioxide concentration comparison unit determines that the change value of the carbon dioxide concentration Cc in the sample gas is greater than or equal to the carbon dioxide concentration change reference value Rc, the It includes an alcohol concentration comparison unit that compares the alcohol concentration (Ca) in the sample gas with a predetermined alcohol concentration reference value (Ra) based on the electrical signal measured by the alcohol sensor,

When the alcohol concentration comparator determines that the alcohol concentration (Ca) in the sample gas is less than a predetermined alcohol concentration reference value (Ra), a drunk driving prevention device is provided to control the starting device to start the vehicle.

In addition, the controller,

If the alcohol concentration comparison unit determines that the alcohol concentration (Ca) in the sample gas is equal to or greater than the reference value (Ra), the alcohol concentration (Ca) in the sample gas and the predetermined maximum value (Cmax) of the carbon dioxide in the sample gas It further includes a blood alcohol concentration calculator for calculating the driver's blood alcohol concentration (BAC) based on the value divided by the concentration (Cc) of,

When it is determined that the blood alcohol concentration (BAC) calculated by the blood alcohol concentration calculating unit is less than a reference value, a drunk driving prevention device is provided for controlling a starting device to start a vehicle.

In the drunk driving prevention apparatus according to the present invention, when a driver rides in a vehicle and blows exhaled gas toward a drunk driving prevention apparatus installed on a steering wheel of a driver's seat or a sun visor, whether or not drinking is immediately confirmed within a short time of about 3 seconds.

In addition, when the driver intentionally blows the exhaled gas weakly, the ignition lock state is maintained.

In addition, it is possible to clearly check whether the driver is drinking alcohol even when there are several passengers.

1 is a block diagram of an apparatus for preventing drunk driving according to an embodiment of the present invention.

2 is a schematic diagram of the drunk driving prevention apparatus shown in FIG. 1.

3 is a cross-sectional view of the carbon dioxide sensor shown in FIG. 2.

4 is a side cross-sectional view of the alcohol sensor shown in FIG. 2.

5 is a side cross-sectional view of the alcohol sensor module shown in FIG. 4.

6 is a block diagram of the controller shown in FIG. 1.

7 is a diagram illustrating a change over time of an electrical signal of a carbon dioxide sensor.

8 is a flow chart for explaining the operation of the drunk driving prevention device shown in FIG.

9 is a schematic diagram of an apparatus for preventing drunk driving according to another embodiment of the present invention.

10 is a schematic diagram of an apparatus for preventing drunk driving according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below and may be embodied in other forms. In addition, in the drawings, the width, length, thickness, etc. of the component may be exaggerated for convenience. The same reference numbers throughout the specification indicate the same elements.

1 is a block diagram of an apparatus for preventing drunk driving according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of an apparatus for preventing drunk driving according to an embodiment of the present invention.

The drunk driving prevention device 1 is installed in a position where the driver can easily blow exhaled gas, such as a sun visor or steering wheel of a driver's seat.

1 and 2, the drunk driving prevention apparatus 1 according to an embodiment of the present invention includes a carbon dioxide sensor 100, an alcohol sensor 200, and a controller 250 (not shown in FIG. 2). do. The carbon dioxide sensor 100 serves to transmit an electric signal according to the concentration of carbon dioxide contained in the mixture of the driver's exhaled gas and the air inside the vehicle to the controller 250. The alcohol sensor 200 serves to transmit an electric signal according to the concentration of alcohol contained in the mixture of the driver's exhaled gas and the air inside the vehicle to the controller 250. The controller 250 controls the vehicle starting device by using these electric signals.

In addition, as shown in Figures 1 and 2, the drunk driving prevention apparatus 1 according to an embodiment of the present invention connects the suction pump 150, the carbon dioxide sensor 100 and the inlet of the suction pump 150 It includes a connection pipe 120, an exhaust pipe 170 connecting the outlet of the suction pump 150 and the alcohol sensor 200.

1 and 2, the carbon dioxide sensor 100 and the suction pump 150 are connected through a connection pipe 120. Therefore, when the suction pump 150 is operated, the sample gas flows into the carbon dioxide sensor 100. The sample gas is the driver's exhaled gas diluted by the air inside the vehicle.

As the suction pump 150, a diaphragm pump may be used. The diaphragm pump is a kind of positive displacement pump that sucks and discharges fluid by the motion of the diaphragm. The positive displacement pump has an advantage in that it has excellent quantitative characteristics and is hardly affected by pressure changes at the outlet side.

One end of the exhaust pipe 170 is connected to the outlet of the suction pump 150, and a semiconductor alcohol sensor 200 is coupled to the other end of the exhaust pipe 170.

In the present invention, the upstream side and the downstream side are determined based on the direction in which the sample gas flows when the suction pump 150 is operated.

3 is a cross-sectional view of the carbon dioxide sensor shown in FIG. 2. The carbon dioxide sensor shown in FIG. 3 is an infrared gas sensor.

Referring to FIG. 3, the carbon dioxide sensor 100 includes an optical waveguide 10, an infrared light source 20, an optical sensor 30, a band pass filter 40, a downstream transparent layer 50, and an upstream transparent layer 55. , A downstream side light guide 60, and an upstream side light guide 65.

Infrared light irradiated from the infrared light source 20 proceeds while being reflected inside the optical waveguide 10 and reaches the optical sensor 30. At this time, the intensity of light having a wavelength absorbed by carbon dioxide among infrared rays reaching the optical sensor 30 varies according to the concentration of carbon dioxide in the sample gas flowing inside the optical waveguide 10. The carbon dioxide sensor 100 calculates the concentration of carbon dioxide contained in the exhalation of the subject by using the change in the intensity of light of such a specific wavelength.

3, the optical waveguide 10 is a straight metal tube. The optical waveguide 10 may be made of copper or a copper alloy, for example, a brass tube. The optical waveguide 10 is a passage through which the sample gas passes. In addition, the optical waveguide 10 is a passage through which infrared rays irradiated into the interior thereof are reflected while being reflected on the inner surface thereof.

A sample gas inlet pipe 11 is coupled to the lower right side of the optical waveguide 10, and the sample gas flows into the sample gas inlet pipe 11. In addition, a sample gas outlet pipe 12 is coupled to the lower left side of the optical waveguide 10.

A heater (not shown) is installed around the optical waveguide 10. As a heater, a film-type heater can be used. Since a large amount of water vapor is included in the exhalation, when the temperature of the sample gas falls below about 33°C, the water vapor contained in the sample gas is condensed and moisture is condensed in the optical waveguide 10. Since gases such as alcohol are easily dissolved in moisture, when moisture condenses, the concentration of gas dissolved in moisture such as alcohol in the sample gas decreases. Therefore, it is necessary to maintain the temperature of the optical waveguide 10 at a constant temperature of 33°C or higher. The heater heats the optical waveguide 10 so that the inside of the optical waveguide 10 is maintained at a constant temperature.

In addition, an insulating material may be disposed around the optical waveguide 10 to minimize heat loss.

The infrared light source 20 is installed at the right end of the optical waveguide 10 to be spaced apart from the optical waveguide 10. The infrared light source 20 emits infrared light including light of a specific wavelength absorbed by carbon dioxide.

And between the infrared light source 20 and the open upstream end of the optical waveguide 10, an upstream side optical guide 65 and an upstream side transparent layer 55 are arranged in sequence. The upstream light guide 65 is a hollow tube having an inclined inner surface to guide light, and may be made of a copper alloy or copper material such as brass. The upstream optical guide 65 serves to guide the light irradiated from the infrared light source 20 to the open upstream end of the optical waveguide 10.

The upstream transparent layer 55 prevents the sample gas flowing into the optical waveguide 10 from flowing toward the infrared light source 20, and passes at least a specific wavelength that reacts to carbon dioxide among the infrared rays emitted from the infrared light source 20. Do it. Since the sample gas may contain foreign substances such as saliva, it is preferable that the introduced sample gas does not contact the infrared light source 20. The upstream transparent layer 55 may be made of transparent glass or film. In addition, an infrared filter that transmits only infrared rays may be used.

The optical sensor 30 is installed at a left end of the optical waveguide 10 to be spaced apart from the optical waveguide 10. The optical sensor 30 detects infrared rays of a specific wavelength reacting with carbon dioxide and converts them into electric signals. The higher the carbon dioxide concentration, the weaker the intensity of infrared rays of a specific wavelength reacting with carbon dioxide.

Between the optical sensor 30 and the open downstream end of the optical waveguide 10, a bandpass filter 40, a downstream optical guide 60, and a downstream transparent layer 50 are sequentially installed.

The bandpass filter 40 serves to selectively pass light of a specific wavelength reacting with carbon dioxide.

The downstream light guide 60 is a hollow tube having an inclined inner surface to guide light, and, like the upstream light guide 65, may be made of a copper alloy or copper material such as brass. The downstream optical guide 60 serves to guide the light passing through the optical waveguide 10 to the bandpass filter 40.

The downstream transparent layer 50 prevents the sample gas flowing into the optical waveguide 10 from flowing toward the optical sensor 30, and passes at least a specific wavelength that reacts to carbon dioxide among the infrared rays emitted from the infrared light source 20. Do it. Since the sample gas may contain foreign substances such as saliva, it is preferable that the introduced sample gas does not come into contact with the band pass filter 40. Like the upstream transparent layer 55, the downstream transparent layer 50 may be formed of a transparent glass or film. In addition, an infrared filter that transmits only infrared rays may be used.

4 is a side cross-sectional view of the alcohol sensor shown in FIG. 2.

As shown in FIG. 4, the alcohol sensor 200 includes a sample gas passage 210 and at least one alcohol sensor module 220 installed in the sample gas passage 210. In this embodiment, four semiconductor type alcohol sensor modules 220 are installed.

The sample gas passage 210 has a substantially rectangular parallelepiped shape, and includes an inlet 211 connected to the exhaust pipe 170 and at least one outlet 212 formed opposite the inlet 211. In addition, at least one alcohol sensor module installation hole 215 is formed on the bottom surface of the sample gas passage 210. It is preferable that the total area of the outlet 212 is smaller than that of the inlet 211. This is to prevent the sample gas from flowing out of the alcohol sensor module 220 and immediately flowing out.

5 is a side cross-sectional view of the alcohol sensor module shown in FIG. 4.

As shown in FIG. 5, each alcohol sensor module 220 includes a housing 221, an insulator substrate 222 installed inside the housing 221, a heating element pattern 223 formed on a lower surface of the insulator substrate 222, A pair of electrodes 224 formed on the upper surface, a sensing film 225 formed on the electrode 224 and a heating element pattern 223, and a plurality of stem pins 226 electrically connected to the electrode 224. In this embodiment, the housing 221 has a cylindrical shape, and through-holes 227 and 228 are formed in the center of the upper end which is an upstream end and the lower end which is the downstream end, respectively. The through-hole 228 formed in the center of the lower end is preferably smaller than the total area of the through-holes 227 formed in the center of the upper end.

Although the insulator substrate 222 is not particularly limited, it is preferable to use an alumina (Al ₂ O ₃ ) substrate. The thickness of about 0.25 mm is mainly used, but is not limited thereto.

The heating element pattern 223 and the electrode 224 are generally formed using platinum (Pt). A method of forming the heating element pattern 223 and the electrode 224 on the insulator substrate 222 is as follows. First, gold is formed on the surface of the alumina substrate using a laser so that the heating element pattern 223 can be cut in units of cells. Next, the surface of the alumina substrate on which gold is formed is cleaned. Then, platinum paste is applied to both surfaces of the washed alumina substrate by a screen printing method and then dried to form a heating element pattern and an electrode. The heating element pattern is generally formed in a zigzag shape to allow sufficient heat generation. Finally, heat treatment is performed in a vacuum or reducing atmosphere to remove the binder in the platinum paste and sinter the platinum.

The sensing film 225 is a thick film whose resistance value is changed by reacting with alcohol in the sample gas at high temperature.

The stem pin 226 serves to support the insulator substrate 222 so as to float at a predetermined height inside the housing 221. The pair of stem pins 226 are electrically coupled to the heating element pattern 223 and serve to apply current to the heating element pattern 223. In addition, the remaining pair of stem pins 226 are connected by an electrode 224 and a conductive material 229 such as silver paste to measure the resistance change of the sensing layer 225.

The sample gas flows into the housing 221 through the upstream side through hole 227. The sample gas flowing into the interior of the housing 221 hits the insulator substrate 222 and then turns around the insulator substrate 222 and is discharged through a through hole 228 formed at the lower end of the housing 221.

6 is a block diagram of the controller shown in FIG. 1.

6, the controller 250 includes a sensor signal receiving unit 251, a carbon dioxide concentration comparing unit 252, an alcohol concentration comparing unit 253, a blood alcohol concentration calculating unit 254, a blood alcohol concentration comparing unit ( 255), a memory 256, and a starter control unit 257.

The sensor signal receiving unit 251 serves to receive electrical signals from the carbon dioxide sensor 100 and the alcohol sensor 100.

7 is a diagram illustrating a change over time of an electrical signal of a carbon dioxide sensor. In FIG. 7, the normal state represents a case in which the driver normally injects exhaled gas toward the drunk driving prevention device 1. The vertical axis represents the electric signal value of the carbon dioxide sensor 100, and the horizontal axis represents the elapsed time based on the point in time when the driver blows the exhaled gas. In addition, one-person boarding and five-person boarding indicate a case in which the driver alone or four other passengers boarded, but the driver did not blow the exhaled gas toward the drunk driving prevention device 1. The horizontal axis represents the elapsed time based on the time of boarding.

As shown in Fig. 7, in a normal state, the electric signal is 2200 mV from about 1000 mV to about 3200 mV in a short period of time within 3 seconds (indicated by the vertical dotted line in Figure 7) after the driver blows in the exhaled gas. Degree increases. Even if the driver does not blow the exhaled gas, the carbon dioxide sensor 100 basically outputs a voltage of about 1000 mV by carbon dioxide inside the vehicle. 2200㎷ of electric signal becomes 2200PPM when converted into carbon dioxide concentration. Therefore, the concentration of carbon dioxide in the sample gas increased by 2200 PPM within 3 seconds by the exhaled gas.

However, if the driver does not blow in the exhaled gas, the electric signal increases slowly compared to the normal state even if there are many passengers. In the case of single-person boarding, it reaches 2000㎷ only after 70 seconds have elapsed, and in the case of four-person boarding, it reaches 2000㎷ only after 24 seconds.

8 is a diagram showing the change over time of electrical signals of carbon dioxide and alcohol sensors. As shown in FIG. 8, the electrical signal of the alcohol sensor 200 also rapidly increases within 3 seconds. The alcohol sensor 200 used in the preparation of FIG. 8 is a semiconductor type alcohol sensor.

The carbon dioxide concentration comparison unit 252 compares the carbon dioxide concentration change reference value Rc stored in the memory 256 with the change value of the carbon dioxide concentration Cc in the sample gas for a predetermined time. That is, by comparing the electric signal value of the current carbon dioxide sensor 100 with the electric signal value of the carbon dioxide sensor 100 before a predetermined X seconds, a change value of the carbon dioxide concentration (Cc) in the sample gas for X seconds is obtained. And, the obtained change value is compared with the carbon dioxide concentration change reference value (Rc). For example, the predetermined time may be 3 seconds, and the carbon dioxide concentration change reference value Rc may be 1000 PPM.

Referring to FIG. 7 as an example, the current electric signal value is about 3200 mV, and the electric signal value 3 seconds ago is about 1000 mV, so the change value of the carbon dioxide concentration (Cc) in the sample gas for 3 seconds Becomes about 2200 mV. 2200㎷ can be converted into 2200PPM of carbon dioxide concentration. The carbon dioxide concentration comparison unit 252 compares this value with a carbon dioxide concentration change reference value Rc of 1000 mV.

The carbon dioxide concentration comparison unit 252 continuously monitors the electric signal value of the carbon dioxide sensor 100 after the operation of the carbon dioxide sensor 100 starts, and compares the electric signal value 3 seconds before the carbon dioxide concentration Cc Obtain the change value. And this is compared with the reference value of carbon dioxide concentration change (Rc).

As shown in FIG. 7, when the driver does not blow the exhaled gas, the carbon dioxide concentration (Cc) change value for 3 seconds becomes less than 1000 PPM even when measured based on a certain point in time.

The alcohol concentration comparison unit 253 compares the alcohol concentration reference value Rc stored in the memory 256 with the alcohol concentration Ca in the sample gas based on the electric signal of the sensor signal receiving unit 251.

The blood alcohol concentration calculating unit 254 stores the maximum value Cmax of carbon dioxide stored in the memory 256 in the alcohol concentration Ca in the sample gas based on the electric signal of the sensor signal receiving unit 251. The value divided by the carbon dioxide concentration (Cc) in the sample gas based on the signal is multiplied to estimate the alcohol concentration in the exhaled gas. And based on this, the blood alcohol concentration (BAC) is calculated.

The maximum value of carbon dioxide (Cmax) is the maximum value of carbon dioxide contained in the driver's exhaled gas, which is usually about 45000 PPM. The value obtained by dividing the maximum value (Cmax) of carbon dioxide stored in the memory 256 by the concentration of carbon dioxide (Cc) in the sample gas based on the electrical signal of the sensor signal receiving unit 251 indicates the degree of dilution of the exhaled gas. Multiplying the alcohol concentration (Ca) in the gas to obtain the alcohol concentration in the exhaled gas. In addition, since the alcohol concentration in the exhaled gas and the blood alcohol concentration (BAC) are in direct proportion, it is possible to know the blood alcohol concentration (BAC) by knowing the alcohol concentration in the exhaled gas.

The blood alcohol concentration comparison unit 255 compares the blood alcohol concentration reference value stored in the memory 256 with the blood alcohol concentration BAC calculated by the blood alcohol concentration calculator 254.

The starting device control unit 257 generates a control signal for controlling the starting device 1 according to the comparison result of the alcohol concentration comparison unit 253 or the blood alcohol concentration comparison unit 255, and sends the starting device (not shown). Deliver. That is, when the alcohol concentration Ca is less than the alcohol concentration reference value Rc or the blood alcohol concentration BAC is less than the blood alcohol concentration reference value, a control signal is sent to the starter so that the starter is switched to the startable state.

Hereinafter, the operation of the above-described drunk driving prevention apparatus 1 will be described with reference to FIG. 9. 9 is a flow chart for explaining the operation of the drunk driving prevention device shown in FIG.

As shown in FIG. 9, the device 1 for preventing drunk driving is maintained in the start-lock state until the result of the drinking measurement is confirmed (S1).

Next, the measurement preparation step (S2) will be described.

When the drunk driving prevention device 1 is operated, the optical waveguide 10 is heated. The drunk driving prevention device 1 may operate automatically by using a sensor installed in the driver's seat or a sensor installed in the driver's seat side door, or in a manner in which the driver manually turns on the switch.

When it is confirmed that the optical waveguide 10 is sufficiently heated and preparation for measurement is completed, the suction pump 150 is operated. In addition, by using an output device (not shown) such as a display or speaker installed in the drunk driving prevention device 1, it notifies the driver that the measurement preparation is complete.

Next, the carbon dioxide and alcohol concentration measurement step (S3) will be described.

First, a method of measuring the carbon dioxide concentration will be described.

When the driver blows the exhaled gas toward the driver's sun visor or the drunk driving prevention device 1 installed on the steering wheel, the sample gas containing the driver's exhaled gas flows into the optical waveguide 10. The sample gas flowing into the optical waveguide 10 fills the optical waveguide 10. Since both ends of the optical waveguide 10 are blocked by the downstream transparent layer 50 and the upstream transparent layer 55, respectively, the sample gas does not directly contact the infrared light source 20 or the optical sensor 30.

In addition, when the infrared light source 20 is turned on, the infrared rays emitted from the infrared light source 20 pass through the upstream side optical guide 65 and the upstream side transparent layer 55 and are introduced into the optical waveguide 10. The light irradiated into the optical waveguide 10 is reflected from the inner surface of the optical waveguide 10 and proceeds to the optical sensor 30 side (downstream side). At this time, light of a specific wavelength that reacts with carbon dioxide is absorbed by carbon dioxide.

The infrared rays passing through the optical waveguide 10 pass through the downstream transparent layer 50 and are guided by the downstream optical guide 60. The infrared rays pass through the bandpass filter 40 and then reach the optical sensor 30. The bandpass filter 40 reflects or absorbs light except for light of a specific wavelength absorbed by carbon dioxide, and passes only light of a specific wavelength absorbed by carbon dioxide. The optical sensor 30 generates an electric signal according to the intensity of light of a specific wavelength absorbed by carbon dioxide. This electric signal is transmitted to the controller 250 of the drunk driving prevention device 1.

Next, a method of measuring the alcohol concentration will be described.

The sensing film 225 of each alcohol sensor module 220 is heated by the control signal of the controller 250. The sample gas discharged from the carbon dioxide sensor 100 flows into the sample gas passage 210 through the exhaust pipe 170. Some are discharged through the outlet 212 of the sample gas passage 210, and some are respectively introduced into the alcohol sensor module 220. Alcohol contained in the introduced sample gas reacts with the sensing film 225 of the alcohol sensor module 220 to change the resistance value of the sensing film 225. In addition, an electric signal according to a change in resistance value is transmitted to the controller 250.

Next, the carbon dioxide concentration comparison step (S4) will be described.

The carbon dioxide concentration comparison unit 252 of the controller 250 continuously acquires a change value of the carbon dioxide concentration Cc for a predetermined time, for example, 3 seconds after the carbon dioxide sensor 100 is operated. For example, at a time point of 3 seconds, a change value of the carbon dioxide concentration Cc is obtained by comparing the electrical signal values of the carbon dioxide sensor 100 in 3 seconds and 0 seconds. And at the time point of 4 seconds, the change value of the carbon dioxide concentration Cc is obtained by comparing the electric signal values at 4 seconds and 1 second.

Then, the obtained change value is compared with a predetermined reference value for change in carbon dioxide concentration (Rc). The change value of the carbon dioxide concentration Cc and the predetermined reference value Rc of change in the carbon dioxide concentration may be a value converted into a concentration, but the electric signal value itself may be compared. The carbon dioxide concentration change reference value Rc may be, for example, 1000 ppm.

If the carbon dioxide concentration comparison unit 252 determines that the change value of the carbon dioxide concentration Cc for a predetermined time is less than the carbon dioxide concentration change reference value Rc, for example, 1000 PPM, the process returns to the carbon dioxide concentration measurement step S2. It continues to receive electrical signals from the carbon dioxide sensor. The reason that the concentration (Cc) of carbon dioxide in the sample gas is less than 1000 ppm may be due to the driver's intentionally blowing a weak exhalation.

When the carbon dioxide concentration comparator 252 determines that the change value of the carbon dioxide concentration Cc for a predetermined time is 1000 ppm or more, the process proceeds to the next step.

Next, the alcohol concentration comparison step (S5) will be described.

The alcohol concentration comparison unit 253 of the controller 250 compares the alcohol concentration Ca based on the electrical signal from the alcohol sensor 100 with a predetermined alcohol concentration reference value Ra. The alcohol concentration reference value Ra may be, for example, 1 ppm.

When it is confirmed that the alcohol concentration (Ca) is less than the alcohol concentration reference value (Ra), the drunk driving prevention device 1 enters the startable state (S8).

When it is confirmed that the alcohol concentration (Ca) is equal to or greater than the alcohol concentration reference value (Ra), the blood alcohol concentration calculation step (S6) proceeds.

Next, the blood alcohol concentration calculation step (S6) will be described.

In this step, the blood alcohol concentration calculating unit 254 of the controller 250 is based on a value obtained by dividing the concentration of alcohol in the sample gas (Ca) and the predetermined maximum value of carbon dioxide (Cmax) by the concentration of carbon dioxide in the sample gas (Cc). The driver's blood alcohol concentration (BAC) is calculated.

The maximum value of carbon dioxide (Cmax) is the maximum amount of carbon dioxide contained in the driver's exhaled gas, which is usually about 45,000 PPM.

For example, if the concentration of alcohol (Ca) and the concentration of carbon dioxide (Cc) in the sample gas were measured as 1 PPM and 1000 PPM, respectively, considering the degree of dilution of the exhaled gas, the actual alcohol concentration in the exhaled gas is 1 PPM × (45,000 PPM). ÷1,000PPM) = It is calculated as 45PPM. And since the alcohol concentration in the exhaled gas is proportional to the blood alcohol concentration, and the blood alcohol concentration of 0.05BAC% corresponds to the alcohol concentration in the exhaled gas of 130 PPM, the alcohol concentration in the exhaled gas 45 PPM is the blood alcohol concentration (BAC) 0.0173BAC% (45 ÷ 130×0.05BAC%).

This step may be carried out using a separate breathalyzer (not shown) connected to the controller. That is, it is also possible to measure the blood alcohol concentration (BAC) by directly blowing exhaled gas into the breathalyzer using a fire band. In particular, when the alcohol concentration (Ca) is low, it is preferable to perform this method in parallel.

Next, a step of comparing the blood alcohol concentration (S7) will be described.

In this step, the blood alcohol concentration (BAC) calculated by the blood alcohol concentration calculating unit 254 or measured using a separate breathalyzer is compared with a reference value, for example, 0.05BAC%. If the blood alcohol concentration (BAC) is less than the reference value, the drunk driving prevention device 1 enters the startable state (S8).

And when the blood alcohol concentration (BAC) is greater than or equal to the reference value, the drunk driving prevention device 1 maintains the starting lock state (S1). In addition, a warning message is transmitted to the driver through an output device such as a speaker or a display.

10 is a schematic diagram of an apparatus for preventing drunk driving according to another embodiment of the present invention. In this embodiment, since the structure of the exhaust pipe 175 and the alcohol sensor 300 is different from the embodiment shown in FIG. 2, only this will be described.

In the embodiment shown in FIG. 2, the sample gas passage 210 of the semiconductor alcohol sensor 200 is connected to the open other end of the exhaust pipe 170, but in this embodiment, the alcohol sensor ( 300) is installed. It is important that a quantitative sample gas flows into the detection unit 320 of the alcohol sensor 300.

The alcohol sensor 300 includes a sensing unit 320 and a suction pump 340 for an alcohol sensor.

The sensing unit 320 includes a sample gas chamber 310 and a reaction cell 314 installed in the inner space 313 of the sample gas chamber 310.

In the sample gas chamber 310, the sample gas inlet pipe 311 through which the sample gas flows in, the sample gas outlet pipe 312 through which the sample gas flows out, and the sample gas flowing in the sample gas inlet pipe 311 flow out the sample gas. It has an inner space 313 that guides the flow in the direction of the tube 312.

The sample gas inlet pipe 311 of the sample gas chamber 310 is connected to the exhaust pipe 175, and the sample gas outlet pipe 312 is connected to the suction pump 340 for an alcohol sensor.

A reaction cell 314 is installed in the inner space 313 between the sample gas inlet pipe 311 and the sample gas outlet pipe 312 of the sample gas chamber 310. The reaction cell 314 outputs a current value that changes according to the alcohol concentration of the sample gas.

The reaction cell 314 includes a sensing electrode and an opposite electrode, and an electrolyte interposed between the sensing electrode and the opposite electrode. Alcohol decomposed into ions in the sensing electrode passes through the electrolyte and then moves to the counter electrode. The generated current value becomes a detection signal value proportional to the alcohol concentration.

The alcohol sensor suction pump 340 serves to suck a quantity of the sample gas flowing through the exhaust pipe 175 into the sample gas chamber 310. The alcohol sensor suction pump 340 is installed to communicate with the sample gas outlet pipe 312 of the sample gas chamber 310. The alcohol sensor suction pump 340 is instantaneously operated after a certain time elapses after carbon dioxide is sensed to collect a quantitative sample gas. A solenoid pump may be used as the suction pump 340 for the alcohol sensor.

Hereinafter, the operation of the drunk driving prevention apparatus 2 according to the present embodiment will be described.

Since the other steps are not different from the above steps, only the action of the alcohol sensor will be described.

When it is confirmed that the concentration Cc of carbon dioxide based on the electric signal from the carbon dioxide sensor 100 is greater than or equal to the reference value Rc, after a while, the suction pump 340 for the alcohol sensor is operated by the control signal of the controller 250, A quantitative sample gas is introduced into the sample gas chamber 310.

At this time, the alcohol sensor suction pump 340 may be continuously operated a plurality of times. That is, by applying power to the solenoid actuator of the alcohol sensor suction pump 340 a plurality of times at short intervals, the alcohol sensor suction pump 340 may be continuously operated a plurality of times. In this way, when a large amount of exhaled gas is introduced into the sample gas chamber 310, the alcohol concentration can be more accurately measured even when the alcohol concentration is low. When the operation is performed multiple times, the controller 250 corrects the alcohol concentration value in consideration of this.

The alcohol contained in the introduced sample gas is completely decomposed into ions in the sensing electrode of the reaction cell 314 installed in the sample gas chamber 310 and then passes through the electrolyte and moves to the counter electrode. The current value generated at this time becomes a detection signal value proportional to the alcohol concentration.

11 is a schematic diagram of an apparatus for preventing drunk driving according to another embodiment of the present invention.

In this embodiment, unlike the embodiment shown in FIG. 10, the suction pump for an alcohol sensor is not used, and the valves 430 and 440 are opened between the exhaust pipe 175 and the sensing unit 420 Each is installed at the end.

In this embodiment, when it is confirmed that the concentration Cc of carbon dioxide based on the electric signal from the carbon dioxide sensor 100 is greater than or equal to the reference value Rc, the exhaust pipe 175 and the detection unit ( As the valve 440 between the valves 420 is opened and the valve 430 installed at the open end of the exhaust pipe 175 is closed, the sample gas flowing through the exhaust pipe 175 is introduced into the sample gas chamber 310. When a fixed amount of sample gas is supplied to the sensing unit 420 after a certain period of time, the valve 440 between the exhaust pipe 175 and the sensing unit 420 is closed, and the valve 430 installed at the open end of the exhaust pipe 175 ) Opens.

The alcohol contained in the introduced sample gas is completely decomposed into ions by the sensing electrode of the reaction cell 414 installed in the sample gas chamber 410 and then passes through the electrolyte and moves to the counter electrode. The current value generated at this time becomes a detection signal value proportional to the alcohol concentration.

The controller 250 measures the concentration of alcohol through the detection signal value and compares the concentration of alcohol Ca with a predetermined value Ra.

The above-described embodiments are merely describing preferred embodiments of the present invention, and the scope of the present invention is not limited to the described embodiments, and those skilled in the art within the scope of the technical spirit and claims of the present invention Various changes, modifications, or substitutions may be made by this, and such embodiments are to be understood as being within the scope of the present invention.

For example, the optical waveguide 10 has been described as a straight metal tube, but may be a U-shaped metal tube.

In addition, in the embodiment shown in FIG. 11, it has been described that valves 430 and 440 are respectively installed between the exhaust pipe 175 and the sensing unit 420 and at the open end of the exhaust pipe 175, but the open end of the exhaust pipe It is also possible to install a three-way valve on the three-way valve and a sample gas chamber on one outlet side of the three-way valve. During measurement, the three-way valve may be controlled so that the sample gas is directed to the sample gas chamber, and during non-measurement, the three-way valve may be controlled so that the sample gas is discharged to the outside through the open end of the exhaust pipe.

[Explanation of code]

1, 2, 3: drunk driving prevention device

100: carbon dioxide sensor

120: connector

150: suction pump

170, 175: exhaust pipe

200: semiconductor alcohol sensor

300, 400: chemical formula alcohol sensor

320, 420: detection unit

340: suction pump for alcohol sensor

430, 440: valve

Claims (6)

1. Includes a sample gas inlet pipe through which the sample gas in which the driver's exhaled gas and the air inside the vehicle are mixed and a sample gas outlet pipe through which the introduced sample gas is discharged, and included in the sample gas introduced through the sample gas inlet pipe A carbon dioxide sensor that generates an electric signal according to the concentration of carbon dioxide

   A suction pump connected to the sample gas outlet pipe of the carbon dioxide sensor and for introducing a sample gas into the carbon dioxide sensor during operation,

   An exhaust pipe connected to the outlet of the suction pump,

   An alcohol sensor that generates an electric signal according to the alcohol concentration of the sample gas flowing through the exhaust pipe,

   And a controller configured to control the starting device of the vehicle by determining whether the vehicle is in a drinking state based on electrical signals from the carbon dioxide sensor and the alcohol sensor,

   The controller,

   The change value of the carbon dioxide concentration (Cc) in the sample gas for X seconds obtained by comparing the electric signal value of the current carbon dioxide sensor with the electric signal value of the carbon dioxide sensor before a predetermined X seconds is based on a predetermined change in carbon dioxide concentration. A carbon dioxide concentration comparison unit comparing the value Rc, and

   If the carbon dioxide concentration comparison unit determines that the change value of the carbon dioxide concentration (Cc) in the sample gas is more than the carbon dioxide concentration change reference value (Rc), the alcohol concentration in the sample gas ( It includes an alcohol concentration comparison unit for comparing Ca) with a predetermined alcohol concentration reference value (Ra),

   When the alcohol concentration comparator determines that the alcohol concentration (Ca) in the sample gas is less than a predetermined alcohol concentration reference value (Ra), the apparatus for preventing drunk driving controls a starting device to start the vehicle.
2. The method of claim 1,

   The controller,

   If the alcohol concentration comparison unit determines that the alcohol concentration (Ca) in the sample gas is equal to or greater than the reference value (Ra), the alcohol concentration (Ca) in the sample gas and the predetermined maximum value (Cmax) of the carbon dioxide in the sample gas It further includes a blood alcohol concentration calculator for calculating the driver's blood alcohol concentration (BAC) based on the value divided by the concentration (Cc) of,

   When it is determined that the blood alcohol concentration (BAC) calculated by the blood alcohol concentration calculating unit is less than a reference value, the apparatus for preventing drunk driving controls the starter to enable the vehicle to be started.
3. The method of claim 1,

   Further comprising a breathalyzer for measuring the driver's blood alcohol concentration (BAC),

   The controller,

   When the alcohol concentration comparison unit determines that the alcohol concentration (Ca) in the sample gas is greater than or equal to the reference value (Ra), the blood alcohol concentration (BAC) measured by the breathalyzer is received, and the blood alcohol measured by the breathalyzer When it is determined that the concentration (BAC) is less than the reference value, a drunk driving prevention device that controls the starter so that the vehicle can be started.
4. The method of claim 1,

   The carbon dioxide concentration comparison unit compares the current electrical signal value of the carbon dioxide sensor and the electrical signal value of the carbon dioxide sensor 3 seconds before, and determines whether the concentration of carbon dioxide (Cc) in the sample gas increases by 1000 ppm or more for 3 seconds. Device.
5. The method of claim 1,

   The alcohol sensor,

   A sample gas chamber connected to the exhaust pipe,

   A sensing cell disposed inside the sample gas chamber,

   A first valve installed to connect or block a path between the exhaust pipe and the sample gas chamber,

   And a second valve installed to open or block the open end of the exhaust pipe,

   The controller,

   When the concentration of carbon dioxide according to the electric signal of the carbon dioxide sensor is greater than or equal to a predetermined value, the first valve is opened and the second valve is shut off. After a certain period of time, the first valve is shut off, and the first valve is shut off. A drunk driving prevention device that controls the first valve and the second valve so that the second valve is opened.
6. The method of claim 1,

   The alcohol sensor,

   A three-way valve installed in the exhaust pipe,

   A sample gas chamber connected to the three-way valve,

   It includes a sensing cell disposed inside the sample gas chamber,

   The controller,

   When the concentration of carbon dioxide according to the electric signal of the carbon dioxide sensor is higher than a predetermined value, the three-way valve is controlled so that the sample gas flows toward the sample gas chamber, and after a certain time elapses, the sample through the open end of the exhaust pipe A drunk driving prevention device that controls a three-way valve so that gas is discharged to the outside.

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