JP5141524B2 - Gas component detector - Google Patents

Description

  The present invention relates to a gas component detection device that measures the alcohol concentration of a subject's breath.

In recent years, drunk driving has become a very social problem, and an apparatus for determining whether or not a driver has drunk has been proposed. As a technique in such a field, for example, an inspection apparatus described in Patent Document 1 below is known. This inspection apparatus introduces exhaled breath inhaled by a subject and detects the alcohol concentration of the subject's exhalation by an alcohol concentration sensor.
JP 2006-201097 A

  In this type of inspection apparatus, in order to accurately measure the alcohol concentration, it is necessary to stably guide the inhaled breath to the alcohol concentration sensor. However, when the subject inhales exhalation toward the apparatus, the exhalation angle and the amount of exhalation may not be stable, and the amount of exhalation to the sensor may not be stable. With respect to this problem, the inspection apparatus of Patent Document 1 employs a mouthpiece, and the subject inhales exhaled air from the mouthpiece of the inspecting apparatus, so that the inhaled exhaled gas is relatively stably guided to the alcohol concentration sensor. Is done. However, the method in which the subject injects exhaled air with the mouthpiece of the inspection device is not necessarily hygienic.

  Then, an object of this invention is to provide the gaseous component detection apparatus which can test | inspect hygienically, introducing a test subject's expiration | expired_air stably.

The present invention provides a gas component that introduces exhaled breath that has been blown into a sensor chamber by a subject into the sensor chamber through the vent and determines the alcohol concentration of the subject's breath by alcohol detection means disposed in the sensor chamber. A detection device that is provided at the air inlet and sucks inhaled air that is blown into the air outlet and introduces it into the sensor chamber, and air that detects or estimates the amount of the air that is blown into the air outlet Determining means for determining whether the detection of the alcohol concentration is an initial inspection or a re-inspection after the detection of the alcohol concentration in the initial inspection has failed, and the blowing by the suction means The amount of air that includes the exhaled air from the mouth is changed according to the amount of the exhaled air that is blown into the air inlet, and the suction means is If the unit determines that the a re-examination again when giving sprayed with the breath to the blowing port, characterized by a number in comparison with the first time inspecting the introduction amount to be introduced through the blowing port.

  According to this gas component detection device, even when the amount of air blown into the air inlet is difficult to stabilize, such as when the subject blows exhaled air from a position away from the air inlet, Since the amount of exhaled air introduced is changed, an appropriate amount of exhaled air component for alcohol concentration detection can be stably introduced. Therefore, the test subject can inhale exhalation into the insufflation port in a non-contact manner, and can perform the examination hygienically.

  In this case, if the alcohol concentration detection fails due to insufficient amount of exhalation into the insufflation port, in the second test, exhalation is aspirated and a larger amount of exhalation components from the insufflation port than at the previous failure. Since it can be introduced, the possibility of another failure is reduced.

In the gas component detection device of the present invention , the blowing amount means has imaging means for imaging the face of the subject, and is based on the distance between the subject's mouth and the inlet and the shape of the subject's mouth taken by the imaging means. Thus, the amount of exhaled air to the air inlet may be estimated.

  In this case, the blowing amount is obtained by estimation. For example, it is possible to estimate the amount of exhalation into the insufflation port from the difference between the direction of the subject's exhalation and the direction of the insufflation port. And even when it is estimated that the amount of inhalation is not appropriate, since exhalation is aspirated and introduced with the amount of inhalation based on that estimation, the amount of exhalation introduced from the insufflation port is changed to be suitable for alcohol concentration detection. An amount of exhaled component can be stably introduced.

Further, in the gas component detection device of the present invention , the subject is a driver of the vehicle, based on the alcohol concentration detected when the air in the vehicle is aspirated and the alcohol concentration detected when the subject blows the breath, The alcohol concentration of the subject's breath may be obtained.

  According to this gas component detection device, the first alcohol concentration in the atmosphere in the vehicle is also separately detected. Therefore, the influence of the alcohol contained in the atmosphere in the vehicle is removed, and the alcohol concentration in the driver's breath is accurately determined. Can get to. Therefore, when this gas component detection device is used in a vehicle to check the expiration of the driver of the vehicle, for example, even if alcohol exists in the vehicle due to the influence of the passenger of the vehicle, etc. The alcohol concentration derived from the exhalation of the driver can be accurately obtained by the general correction.

  According to the gas component detection device of the present invention, it is possible to perform a hygienic examination while stably introducing the breath of the subject.

  Hereinafter, an alcohol concentration detection apparatus as a preferred embodiment of a gas component detection apparatus according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows a block diagram of an alcohol concentration detection apparatus 1 according to the first embodiment of the present invention, and FIG. 2 shows a perspective view of its appearance. The alcohol concentration detection device 1 is a device mounted on an automobile, and is used to detect the alcohol concentration of the exhaled breath by introducing the driver's exhalation. Hereinafter, such a test for detecting the alcohol concentration of the subject's breath may be referred to as an “alcohol test”. As shown in FIG. 1, the alcohol concentration detection device 1 includes a sensor chamber 3 that is defined in a housing and into which a subject's breath is introduced. Sensors such as an alcohol sensor 11, an oxygen sensor 13, an interference gas sensor 15, and a humidity sensor 17 are provided in the sensor chamber 3. Furthermore, the alcohol concentration detection apparatus 1 includes an ECU (Electronic Control Unit) 5 that receives signals from the sensors and performs information processing. The ECU 5 is an electronic control unit that controls the alcohol concentration detector 1 as a whole. The ECU 5 is physically composed of, for example, a CPU, and includes a ROM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit, and the like. Yes.

  The sensor chamber 3 is provided with an air inlet 7 opened to the subject side. When the subject blows exhalation toward the blowing port 7 without bringing the mouth into contact with the blowing port 7, the exhalation of the subject is introduced into the sensor chamber 3. A suction fan 9 for sucking exhaled air from the subject to the sensor chamber 3 side is attached to the back side of the air inlet 7. The suction fan 9 sucks gas outside the sensor chamber 3 and introduces the gas into the sensor chamber 3 through the blow-in port 7. By adjusting the rotation of the suction fan 9, exhaled air introduced into the sensor chamber 3. The introduction flow rate can be adjusted. Further, the breath that has been sent in can be agitated in the sensor chamber 3 by the rotation of the suction fan 9. The suction fan 9 is connected to the ECU 5 via a fan control circuit 9a, and the ECU 5 controls the rotational speed of the suction fan 9 by transmitting a control signal to the fan control circuit 9a. For example, by increasing the rotation speed of the suction fan 9, the suction force and the suction flow rate of exhalation can be increased, the introduction flow rate of exhalation can be increased, and by reducing the rotation speed of the suction fan 9, It is possible to reduce the exhalation suction force and the suction flow rate, and to reduce the exhalation introduction flow rate. In the sensor chamber 3, the side opposite to the air inlet 7 is open.

  The alcohol sensor 11 detects the alcohol concentration of the breath introduced into the sensor chamber 3, and sends the concentration information to the ECU 5 as an electrical signal. As such an alcohol sensor 11, for example, a semiconductor alcohol sensor is used. The semiconductor alcohol sensor utilizes the characteristic that the amount of electrons originally flowing in the semiconductor is absorbed and changed by the alcohol in the breath. In the semiconductor alcohol sensor based on this principle, the electrical resistance in the sensor changes as the amount of electrons in the semiconductor changes, so the alcohol concentration in the breath of the person being measured is estimated from the strength of the electrical resistance. Can do. Further, as another type of alcohol sensor 11, a sensor using a fuel cell or a sensor using infrared rays can be applied.

  The oxygen sensor 13 detects the oxygen concentration of the breath in the sensor chamber 3, and the humidity sensor 17 detects the humidity of the breath in the sensor chamber 3. In the ECU 5, the flow rate of the exhaled breath is obtained from the change in oxygen concentration and the change in humidity when exhaled breath is introduced. Further, the interfering gas sensor 15 detects a gas component included in the bad breath of the subject. By detecting such a gas component with the interfering gas sensor 15, the ECU 5 discriminates the alcohol concentration other than the alcohol component caused by drinking out of the alcohol contained in the breath of the subject, and other than the alcohol component caused by drinking The effects of alcohol can be removed afterwards.

  In addition, the alcohol concentration detection device 1 further includes a blowing amount sensor 21 provided in the vicinity of the blowing port 7. The inhalation amount sensor 21 detects the amount of exhalation actually blown into the insufflation port 7 out of the exhalation blown toward the insufflation port 7 by the subject (hereinafter sometimes simply referred to as “inhalation amount”), and the electric signal As a function of transmitting to the ECU 5. The blowing amount sensor 21 can also detect the flow rate of exhaled breath at the blowing port 7. For example, the insufflation sensor 21 is a temperature sensor that can detect the insufflation amount due to a rise in temperature due to the exhalation, a pressure sensor that can detect the insufflation amount due to an increase in pressure due to the exhalation, or a flow rate of expiration. Thus, a flow sensor or the like that can detect the blowing amount can be employed.

  In the alcohol concentration detection device 1, in order to correctly detect the alcohol concentration of exhaled breath, it is necessary to sufficiently introduce the exhalation component into the sensor chamber 3. However, in this alcohol concentration detection device 1, since the subject blows in exhaled air from a position away from the air inlet 7 without touching the mouthpiece, the amount of exhaled air into the air inlet 7 is relatively difficult to stabilize. For example, when the exhaled breath blown by the subject flies in a direction deviating from the blowing port 7, only a part of the exhaled breath blown by the subject is blown into the blowing port 7, and the blowing amount becomes insufficient. If the blowing amount is insufficient, alcohol detection by the alcohol sensor 11 becomes impossible and the alcohol test fails. In view of such a problem, the alcohol concentration detection device 1 varies the number of rotations of the suction fan 9 in order to vary the amount of exhalation introduced into the sensor chamber 3 according to the amount of exhalation into the air inlet 7. It is said. Hereinafter, specific processing of the alcohol concentration detection apparatus 1 in the alcohol test will be described with reference to FIG.

  First, when the inspection is started, the ECU 5 controls the suction fan 9 so as to rotate at a predetermined default rotation speed (S101). Thereafter, for example, by displaying the display prompting the subject to blow exhalation by means of lamp lighting or the like, the exhalation of the subject is blown toward the blowing port 7 (S103). At this time, the ECU 5 recognizes the amount of exhaled air into the air inlet 7 based on the signal from the air amount sensor 21 (S105). Then, the ECU 5 controls the rotation of the suction fan 9 at the rotation speed determined based on the recognized blowing amount (S107). Specifically, the rotation speed of the suction fan 9 is decreased as the amount of exhalation into the air inlet 7 is increased, and the rotation speed of the suction fan 9 is increased as the amount of exhalation into the air inlet 7 is decreased. Is done. Then, the ECU 5 detects the alcohol concentration of the subject's breath based on the signal from the alcohol sensor 11 (S109).

  Next, the effect by such an alcohol concentration detection apparatus 1 is demonstrated. In the alcohol test by the device 1, when the amount of exhaled breath to the air inlet 7 is small, the suction fan 9 rotates at a higher speed. Then, since the suction force for sucking the exhalation outside the blowing port 7 is strong, more exhalation components are introduced into the sensor chamber 3. Therefore, even when the blowing amount is small, an amount of the breath component necessary for alcohol detection is easily introduced into the sensor chamber 3. Therefore, according to the alcohol concentration detection apparatus 1, the possibility of failure of the alcohol test is reduced. As described above, since the possibility of the test failure is reduced, the insufflation of the exhalation amount is allowed to some extent. Therefore, it is not necessary to employ a mouthpiece or the like for the blowing port 7, and the subject may blow exhalation without contact from a position away from the blowing port 7. Therefore, according to the alcohol concentration detection device 1, a hygienic inspection can be performed. In addition, since the mouthpiece is not employed, troubles such as cleaning the mouthpiece can be omitted.

(Second Embodiment)
As shown in FIGS. 1 and 2, the alcohol concentration detection device 201 according to the second embodiment of the present invention has the same hardware configuration as that of the alcohol concentration detection device 1 described above, and thus redundant description is omitted. To do.

  In the alcohol concentration detection apparatus 201, in order for the alcohol sensor 11 to detect alcohol, the flow rate of the exhaled breath into the sensor chamber 3 needs to be appropriate at the detection timing of the alcohol sensor 11. Therefore, even when the flow rate of the breath into the breathing port 7 by the subject slightly deviates from the appropriate flow rate α, as shown in the graph Ha in FIG. 4A and the graph Hb in FIG. The suction flow rate or the resistance force 9 adjusts the flow rate introduced into the sensor chamber 3 to the appropriate flow rate α. By adjusting the introduction flow rate as described above, the time during which the appropriate flow rate α is maintained within the detection timing Y of the alcohol sensor 11 (Ta, Tb in the figure: hereinafter referred to as “sensor detection time”) is secured to some extent. Is done. However, as shown by the graph Ja in FIG. 4A, the exhalation flow rate by the subject is excessively large, or as shown by the graph Jb in FIG. 4B, the exhalation flow rate by the subject is too small. If this occurs, it takes time to adjust the flow rate α to the appropriate flow rate α by the suction fan 9, and the sensor detection times Ta1 and Tb1 are shortened. Then, the alcohol sensor 11 cannot detect sufficient alcohol, and the alcohol test fails.

  Therefore, in order to cope with such a problem, the alcohol concentration detection device 201 performs processing different from that of the alcohol concentration detection device 1 in the alcohol test. Hereinafter, specific processing of the alcohol concentration detection apparatus 201 in the alcohol test will be described with reference to FIG.

  When the alcohol test is started, it is first determined whether or not the test to be performed is the first test (S201). Here, the “re-inspection flag” is referred to. When the “re-inspection flag” indicates “0”, it is determined that the initial inspection is performed. When the “re-inspection flag” indicates “1”, It is judged that this is not the first examination. Here, “when it is the first test” means that the alcohol test is performed for the first time, and “when it is not the first test” means that it is a retest due to failure of the previous test. The process of setting “1” or “0” to the “re-examination flag” will be described later.

  If it is determined in S201 that this is the first inspection, the ECU 5 controls the suction fan 9 to rotate at a predetermined default rotation speed (S203). On the other hand, when it is determined in S201 that it is not the first inspection, the suction fan 9 is controlled to rotate at a different rotational speed from the default (S205). Details of the rotation speed control in S205 will be described later.

  Thereafter, for example, by displaying the display prompting the subject to blow exhalation by means of lamp lighting or the like, the exhalation of the subject is blown toward the blowing port 7 (S207). Then, the exhaled air blown into the blowing port 7 passes through the blowing port 7 and is sent into the sensor chamber 3 by the suction fan 9. The exhaled air in the sensor chamber 3 contacts the sensors in the sensor chamber 3 while being agitated by the suction fan 9. At this time, the ECU 5 detects the introduction flow rate of the exhalation in the sensor chamber 3 and the rise time of the exhalation flow based on the signals from the oxygen sensor 13 and the humidity sensor 17 and records them in the information storage unit of the ECU 5 ( S209). Thereafter, it is determined whether or not sufficient alcohol can be detected by the alcohol sensor 11 (S211).

  If it is determined in S211 that “detectable”, the ECU 5 sets “0” in the “retest flag” (S213), and detects the alcohol concentration of the subject's breath based on the signal from the alcohol sensor 11 (S215). If it is determined in S211 that “detection is impossible”, the alcohol test is unsuccessful, so the ECU 5 sets “1” in the “retest flag” (S217), and performs a retest request process (S219). ). In this re-examination request process, for example, a display for urging the subject to breathe again is performed by means such as lamp lighting. Thereafter, the processing of the ECU 5 returns to S201 and is repeated in the same manner.

  Next, a process (S205) when it is determined in S201 that it is not the first inspection will be described. The case where this processing S205 is executed means that the previous alcohol test has failed and the current test is a retest. In this case, the rotational speed is determined based on the exhalation flow rate recorded in the previous examination process S209, and the rotation of the suction fan 9 is controlled so as to be the rotational speed (S205). Thereafter, a display for prompting the subject to blow exhalation is performed (S207).

  Specifically, in S205, when the introduction flow rate recorded in the previous inspection is larger than a predetermined appropriate range, the number of rotations of the suction fan 9 is made smaller than the previous number of rotations and recorded in the previous inspection. When the introduced flow rate is smaller than a predetermined appropriate range, control is performed so that the rotational speed of the suction fan 9 is larger than the previous rotational speed. Here, the case where the previously recorded introduction flow rate is smaller than the predetermined appropriate range corresponds to the case where the previous inspection failed due to the introduction flow rate being too small, and the previously recorded introduction flow rate is a predetermined value. The case where it is larger than the appropriate range corresponds to the case where the previous inspection failed due to an excessively large introduction flow rate. In S205, the control is further performed so that the rotation speed of the suction fan 9 is decreased as the previously introduced flow rate is increased, and the rotation speed of the suction fan 9 is increased as the previously recorded flow rate is decreased. Also good.

  Next, the effect by such an alcohol concentration detection apparatus 201 is demonstrated with reference to Fig.6 (a), (b). Consider the case where the test failed because the exhalation flow rate was too small in the previous test. Such time change of the introduction flow rate at the time of the inspection failure corresponds to the graph Jb in FIG. In this case, since the same subject blows exhalation in this re-examination, it is considered that there is a high possibility that the inflow flow rate is small as in the previous examination. Corresponding to this, the suction fan 9 in the current inspection rotates at a higher speed than the rotation speed in the previous inspection by the process of S205. Then, even if the blowing flow rate to the blowing port 7 is small again, the suction force of the suction fan 9 is increased as compared with the previous inspection, so that the graph Kb in FIG. Then, the flow rate of the exhaled breath into the sensor chamber 3 is quickly adjusted and quickly approaches the appropriate flow rate α. Therefore, the sensor detection time Tb2 becomes longer, and the possibility of inspection failure is reduced.

  Similarly, in the previous test, as shown in the graph Ja in FIG. 6A, even if the test fails because the exhalation flow rate is excessively large, in this test, the suction fan 9 The resistance force is increased compared to the previous inspection, and as a result, as shown in the graph Ka of FIG. 6A, the sensor detection time Ta becomes longer, and the possibility of the inspection failure is reduced. Therefore, in the case where the inspection is performed again after the inspection has failed once, the possibility that the inspection will fail again is reduced.

  Thus, according to the alcohol concentration detection apparatus 201, at the time of re-examination, the rotation speed of the suction fan 9 (that is, the suction force by the suction fan 9) is adjusted according to the introduction flow rate at the previous inspection. In, the introduction flow rate is adjusted more quickly, and the sensor detection time can be made longer than the previous time. Therefore, at the time of re-inspection, the possibility of repeating the inspection failure again can be reduced. In this way, at least during retesting, the possibility of a test failure due to instability of the exhalation of breath is reduced, so that instability of the exhalation of breath is allowed to some extent. Therefore, it is not necessary to employ a mouthpiece or the like for the blowing port 7, and the subject may blow exhalation without contact from a position away from the blowing port 7. As a result, according to the alcohol concentration detection device 201, a hygienic inspection can be performed. In addition, since the mouthpiece is not employed, troubles such as cleaning the mouthpiece can be omitted.

  In the process S207 in the first examination, the rotation speed of the suction fan 9 may be controlled on the basis of the blowing amount to the blowing port 7 detected by the blowing amount sensor 21 when exhalation is blown by the subject. Good.

(Third embodiment)
FIG. 7 shows a block diagram of an alcohol concentration detection apparatus 301 according to the third embodiment of the present invention, and FIG. 8 shows a perspective view of the appearance thereof. The alcohol concentration detection device 301 includes a camera 23 provided in the vicinity of the blowing port 7 instead of the blowing amount sensor 21 in the above-described alcohol concentration detecting device 1 (see FIGS. 1 and 2). The alcohol concentration detection device 301 captures the face of the subject at the time of blowing exhalation with the camera 23, obtains the amount of exhaled breath into the injecting port 7 by using the face image data, and obtains the inhalation obtained by the estimation. Based on the amount, the rotational speed of the suction fan 9 is controlled.

  Specifically, the camera 23 captures an image of the face of the subject who blows the breath to the air inlet 7, converts the face image data into an electrical signal, and transmits the electrical signal to the image processing ECU 25. The image processing ECU 25 performs image processing of the face image in accordance with a predetermined algorithm, estimates the position of the subject's mouth with respect to the air inlet 7, the shape of the subject's mouth, and the like, and transmits them to the ECU 5 as electrical signals.

  The ECU 5 estimates the amount of exhalation into the air inlet 7 by the subject based on information such as the position of the subject's mouth received from the image processing ECU 25 and the shape of the subject's mouth. For example, the image processing ECU 25 can estimate the distance (position in the depth direction of the screen) from the subject's mouth 7 from the size of the subject's face and the size of the facial feature points in the screen. From the position of the mouth in the screen, it is possible to estimate the position of the subject's mouth with respect to the inlet 7 (position in the plane parallel to the screen). In the ECU 5, it is estimated that the closer the position of the subject's mouth is to the blowing port 7, the larger the blowing amount, and the closer the position of the subject's mouth is to the front position of the blowing port 7, the larger the blowing amount is estimated. The Further, the ECU 5 recognizes the direction of the subject's mouth when blowing exhalation based on the position and shape of the subject's mouth, and the subject's mouth is oriented in a direction close to the front with respect to the air inlet 7. The greater the amount of blow, the greater the estimate.

  Further, the amount of exhaled breath into the insufflation port 7 may vary depending on how the subject exhales. For example, according to various experiments conducted by the present inventors, when the subject sharpens his mouth and inhales “Foot”, the exhalation blows in the direction that the subject does not intend, and the inlet 7 In many cases, the amount of air blown into the mouth becomes small, and when the subject opens his mouth and inhales “Haaa”, exhaled air is accurately blown into the mouth 7 and the amount of air blown into the mouth 7 Often increases. Based on this knowledge, the ECU 5 determines whether the subject has a sharp mouth or is open based on the shape of the mouth of the subject when the exhalation is blown. The amount is estimated to be small, and if the mouth is open, the amount to be blown is estimated to be large.

  Next, specific processing of the alcohol concentration detection device 301 in the alcohol test will be described with reference to FIG. First, a display prompting the subject to blow exhalation by means of lamp lighting or the like is performed, so that the exhalation of the subject is blown toward the blowing port 7 (S301). At this time, a face image of the subject at the time of exhalation is taken by the camera 23 (S303). Then, image processing of the face image is performed by the image processing ECU 25, and the position of the mouth of the subject, the shape of the mouth opening, and the like are detected (S305). The ECU 5 obtains the amount of exhalation into the air inlet 7 by estimation based on information from the image processing ECU 25 (S307). Then, the ECU 5 determines the number of rotations of the suction fan 9 based on the blowing amount obtained by the estimation, and controls the rotation of the suction fan 9 (S309). Specifically, the larger the estimated amount of exhaled breath into the air inlet 7 is, the smaller the number of rotations of the suction fan 9 is. The smaller the estimated amount of exhaled air into the air inlet 7 is, the smaller the number of rotations of the suction fan 9 is. Is controlled to be large. Then, the ECU 5 detects the alcohol concentration of the subject's breath based on the signal from the alcohol sensor 11 (S311).

  In this alcohol concentration detection device 301, the same or equivalent components as those of the alcohol concentration detection devices 1 and 201 are denoted by the same reference numerals in the drawings, and redundant description is omitted.

  Also with such an alcohol concentration detection device 301, the same operational effects as those of the alcohol concentration detection device 1 described above can be obtained, and hygienic inspection can be performed.

  In this embodiment, the amount of blowing is estimated based on the face image data from the camera 23 near the blowing port 7, but other information may be used to estimate the amount of blowing. For example, a microphone may be attached in the vicinity of the air inlet 7 to obtain the utterance sound when the subject exhales. In this case, for example, the ECU 5 can estimate how to exhale depending on whether the sound generated by the subject is “haha” or “huo”, so the amount of inhalation is estimated based on the uttered sound. be able to. Further, for example, a pressure sensor may be provided in the vicinity or inside of the blowing port 7 and the blowing amount may be estimated based on pressure increase information due to blowing of exhalation. Further, for example, a temperature sensor may be provided in the vicinity or inside of the blowing port 7 and the blowing amount may be estimated based on the temperature rise information due to the blowing of exhalation. Moreover, you may estimate the amount of blowing by combining each information obtained with these cameras 23, a microphone, a pressure sensor, and a temperature sensor suitably.

(Fourth embodiment)
As shown in FIGS. 1 and 2, the alcohol concentration detection device 401 according to the fourth embodiment of the present invention has the same hardware configuration as that of the alcohol concentration detection device 1 described above, and therefore redundant description is omitted. To do.

  The alcohol concentration detection device 401 is provided in the vehicle and detects the alcohol concentration of the breath of the driver of the vehicle. The information on the alcohol concentration detected here is used in another system, for example, to determine whether or not the driver has drunk and determine whether or not driving is possible. When the alcohol concentration detection device is used in an automobile, an alcohol other than the alcohol derived from the driver's breath may exist in the vicinity of the air inlet 7, which may hinder the driver's alcohol test. For example, when a passenger of an automobile is drunk, alcohol due to the expiration of the passenger is present in the vehicle. And the driver | operator may be misjudged that it is a drinking state by the influence of the alcohol derived from this passenger. Therefore, it is necessary to accurately measure the alcohol concentration of the driver's breath by removing the influence of the alcohol in the vehicle other than the alcohol derived from the driver's breath.

  Therefore, in order to cope with such a problem, the alcohol concentration detection device 401 performs processing different from that of the alcohol concentration detection device 1 in the alcohol test. Hereinafter, specific processing of the alcohol concentration detection apparatus 401 in the alcohol test will be described with reference to FIG.

  First, when the alcohol concentration detector 401 is turned on (S401), the ECU 5 rotates the suction fan 9 to suck air in the vehicle (atmosphere in the vehicle) around the air inlet 7 into the sensor chamber 3. Introduce (S403). In this state, the ECU 5 detects the alcohol concentration of the sucked air in the vehicle based on the signal from the alcohol sensor 11 (S405). Then, the ECU 5 controls the rotation speed of the suction fan 9 based on the detected alcohol concentration (S407). Specifically, the rotation speed of the suction fan 9 is increased as the detected alcohol concentration is increased, and the rotation speed of the suction fan 9 is decreased as the detected alcohol concentration is decreased.

  Then, the processes S405 and S407 are performed until the alcohol concentration detected by the alcohol sensor 11 is equal to or lower than the predetermined concentration (S409) or until a predetermined time-out period elapses without reaching the predetermined concentration (S411). While being repeated, the suction of the air in the vehicle by the suction fan 9 is continued. The vehicle interior air sucked at this time passes through the sensor chamber 3 and is continuously discharged outside the vehicle, for example.

  The process when the alcohol concentration detected by the alcohol sensor 11 is equal to or lower than the specified concentration while the vehicle interior air is being sucked in this way (Yes in S409) will be described. In this case, for example, a display for prompting the driver to blow exhalation is performed by means such as lighting of a lamp, and the exhalation of the driver is blown toward the blowing port 7 (S413). Here, the rotational speed of the suction fan 9 may be controlled based on the blowing amount detected by the blowing amount sensor 21. Then, the ECU 5 detects the alcohol concentration of the driver's breath based on the signal from the alcohol sensor 11 (S415).

  According to such processing, even when alcohol that does not originate from the driver's breath is present in the vicinity of the air inlet 7, such alcohol is sucked into the sensor chamber 3 by the suction fan 9 and discharged outside the vehicle, for example. As a result, the alcohol present in the vicinity of the blowing port 7 can be removed. After the removal of the alcohol is confirmed (Yes in S409), the driver blows exhalation on the air inlet 7, so that the alcohol originally present in the space between the driver's mouth and the air inlet 7 The effect is removed, and the correct alcohol concentration of the driver's breath can be detected.

  Next, a description will be given of processing when a predetermined time-out period elapses without reaching the specified alcohol concentration or less (Yes in S411) even though the in-vehicle air is sucked by the suction fan 9.

  In this case, the ECU 5 records the current alcohol concentration recognized based on the signal from the alcohol sensor 11 in the information storage unit of the ECU 5 as the first concentration (B) indicating the alcohol concentration of the in-vehicle air, and the blowing amount sensor. The current flow rate of air by the suction of the in-vehicle air detected by 21 is recorded in the information storage unit of the ECU 5 as the first flow rate (a1) (S421).

  Next, when the ECU 5 performs a display prompting the driver to blow exhalation by means of, for example, lamp lighting, the driver's exhalation is blown toward the blowing port 7 (S423). In this case, the air inside the vehicle containing alcohol is present in the vicinity of the air inlet 7, and this air inside the vehicle is taken into the exhaled air and blown into the air inlet 7. As a result, the inside of the vehicle containing alcohol is contained in the sensor chamber 3. A mixed gas in which air and the exhalation of the driver are mixed is introduced through the blowing port 7. Then, the ECU 5 detects the alcohol concentration of the mixed gas based on the signal from the alcohol sensor 11 (S425). Then, the alcohol concentration of the mixed gas is recorded in the storage unit as the second concentration (C), and the blowing flow rate of the mixed gas detected by the blowing amount sensor 21 at this time is stored in the information storage unit as the second flow rate (a2). Recording is performed (S427).

Here, the alcohol concentration of the driver's breath includes the alcohol concentration (first concentration B) detected when the air in the vehicle is sucked and the alcohol concentration (second concentration C) of the mixed gas detected when the driver blows the breath. ) And the ratio (a1 / a2) of the air flow rate at the air inlet 7 when the air in the vehicle is introduced and the gas flow rate at the air inlet 7 when the driver exhales Can do. That is, in order to obtain the alcohol concentration D of the driver's breath by removing the influence of the alcohol present in the vehicle from the alcohol concentration (second concentration C) of the mixed gas,
D = C−B × (a1 / a2) (1)
Such a calculation formula may be used. Therefore, the ECU 5 reads the values of a1, a2, B, and C stored in the information storage unit, and calculates the alcohol concentration D of the driver's breath by the above equation (1) based on these values (S429). ).

  According to such processing, even when there is alcohol in the vehicle unrelated to the driver's drinking (for example, when there is a drunk passenger in the vehicle), By removing the influence of irrelevant alcohol by a posteriori correction, the alcohol concentration of the driver's breath can be obtained. Therefore, regardless of the environment in the vehicle, the drinking state of the driver can be more accurately determined based on the detection result by the alcohol concentration detection device 401.

  In addition, according to the alcohol concentration detection device 401, the influence of the alcohol originally present in the vehicle can be removed by a subsequent calculation, so that the alcohol originally present in the vehicle slightly enters the device 401 during the alcohol test. It is permissible. Therefore, it is not necessary to employ a mouthpiece or the like for the blowing port 7, and the subject may blow exhalation without contact from a position away from the blowing port 7. As a result, according to the alcohol concentration detection device 401, a hygienic inspection can be performed. In addition, since the mouthpiece is not employed, troubles such as cleaning the mouthpiece can be omitted.

It is a block block diagram which shows embodiment of the alcohol concentration detection apparatus which concerns on 1st, 2nd and 4th embodiment of this invention. It is a perspective view which shows the external appearance of the alcohol concentration detection apparatus of FIG. (A), (b) is a graph which shows the time change of the introductory flow volume immediately after exhalation blowing. It is a flowchart which shows the process by the alcohol concentration detection apparatus of 1st Embodiment. (A), (b) is a graph which shows the time change of the introductory flow volume immediately after exhalation blowing. It is a flowchart which shows the process by the alcohol concentration detection apparatus of 2nd Embodiment. It is a block block diagram which shows embodiment of the alcohol concentration detection apparatus which concerns on 3rd Embodiment of this invention. It is a perspective view which shows the external appearance of the alcohol concentration detection apparatus of FIG. It is a flowchart which shows the process by the alcohol concentration detection apparatus of 3rd Embodiment. It is a flowchart which shows the process by the alcohol concentration detection apparatus of 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,201,301,401 ... Alcohol density | concentration detection apparatus (gas component detection apparatus), 3 ... Sensor chamber, 5 ... ECU, 7 ... Blowing inlet, 9 ... Suction fan, 21 ... Blowing amount sensor, 23 ... Camera.

Claims (3)

The breath blown into blow port of the sensor chamber by the subject and introduced into the sensor chamber through the blowing port, there a gas component detection device for determining the alcohol concentration of breath of the subject by the arrangement alcoholic detecting means to the sensor chamber And
A suction means provided at the air inlet, for sucking exhaled air blown into the air outlet and introducing it into the sensor chamber;
A blowing amount means for detecting or estimating the blowing amount of the exhalation to the blowing port;
Judgment means for judging whether the detection of the alcohol concentration is an initial inspection or a re-examination after the detection of the alcohol concentration in the initial inspection fails,
With
The introduction amount of the air containing the exhalation from the blowing port by the suction means is changed according to the blowing amount of the exhalation into the blowing port ,
When the determination means determines that the reexamination is performed, the suction means increases the introduction amount introduced through the injection opening when the exhalation is blown again into the injection opening as compared to the initial inspection. A gas component detection device characterized by that. The blowing amount means has an imaging means for imaging the face of the subject, and based on a distance between the mouth of the subject and the blowing mouth imaged by the imaging means and a shape of the mouth of the subject The gas component detection device according to claim 1, wherein an amount of exhalation of air is estimated. The subject is a vehicle driver;
The alcohol concentration of the subject's breath is obtained based on the alcohol concentration detected when the air in the vehicle is sucked and the alcohol concentration detected when the subject blows the breath. 2. The gas component detection apparatus according to 2.

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