JP5120104B2 - Drunk state determination device - Google Patents

Description

  The present invention relates to a drinking level determination device that determines a drinking level, and relates to a drinking level determination device that determines a drinking level of a driver who drives a vehicle.

In recent years, in order to prevent drunk driving, an alcohol interlock system that prevents a vehicle engine from starting when a driver is in a drunk state is being introduced. This alcohol interlock system determines the drinking level of a driver, and conventionally, there is an alcohol detection device using a semiconductor alcohol sensor as a drinking level determination device that determines the drinking level of a driver (see, for example, Patent Document 1). ). This alcohol detection device has an amplification circuit and a differentiation circuit, and can detect the alcohol concentration from the addition result of the amplification circuit and the differentiation circuit to faithfully represent the time change of the alcohol concentration. is there.
JP-A-6-82411

  By the way, when determining the drinking state of the driver, if the driver is ingesting the liquor approximate food and drink, it may be erroneously detected that the alcohol concentration in the exhalation of the driver is high due to components generated from the liquor approximate food and drink. Here, although the alcohol detection device disclosed in Patent Document 1 can express a change in alcohol concentration with time, it has not been possible to prevent erroneous detection when the driver ingests alcoholic beverages. For this reason, when the driver ingested the alcoholic beverage approximate food and drink, there was a problem that it might be determined that it was in a drinking state even though it was not drinking.

  In addition, even after drinking, the alcohol concentration in the driver's breath may be temporarily reduced. For this reason, if the alcohol concentration is detected in a state where the alcohol concentration in the exhalation of the driver has once decreased, there is a problem that it may be determined that the driver is not in a drinking state even though alcohol has been drunk.

  Therefore, an object of the present invention is to provide a drinking state determination device that can perform a highly accurate drinking state determination by preventing erroneous determination in drinking state determination based on alcohol concentration detection in expiration.

A drinking level determination device according to the present invention that solves the above problems is a drinking level determination device that detects the alcohol concentration in the breath of a subject and determines the drinking level of the subject based on the detected alcohol concentration. Te, based on the alcohol concentration detected by the alcohol concentration detection a plurality of times, with the alcohol concentration gradient calculating means for calculating the alcohol concentration gradient based on temporal change in the alcohol concentration, the basis of the alcohol concentration, and alcohol concentration gradient, to And a vaporized gas concentration gradient model storage means for determining a drinking state of the subject and storing a vaporized gas concentration gradient model representing a concentration gradient based on a change with time in the concentration of vaporized gas generated from the liquor approximate food and drink. As the alcohol concentration detected by multiple alcohol concentration detections exceeds the predetermined concentration threshold When the difference between the alcohol concentration gradient calculated in alcohol concentration gradient calculating means and the vaporized gas concentration gradient model is equal to or less than a predetermined threshold value, but determines that the subject is a non-drinking level.

  In the drinking level determination apparatus according to the present invention, based on the alcohol concentration detected by a plurality of times of alcohol concentration detection, a concentration gradient based on a change with time of the alcohol concentration is calculated, and based on the alcohol concentration and the alcohol concentration gradient. The subject's drinking status is determined. When the subject ingests alcoholic beverages or similar foods, even if the alcohol concentration is the same as in the case of ingesting alcoholic beverages, the subsequent alcohol concentration gradient is different. For this reason, by determining the subject's drinking level based on the alcohol concentration and the alcohol concentration gradient, it is possible to prevent misjudgment in the drinking level determination based on detection of the alcohol concentration in exhaled breath, and drinking with high accuracy. State determination can be performed.

  The “concentration gradient based on change over time” in the present invention refers to a value obtained by dividing the amount of change in concentration at the time when a certain time has elapsed by the above-mentioned certain time.

  Here, a vaporized gas concentration gradient model storage means for storing a vaporized gas concentration gradient model representing a concentration gradient based on a change with time in the concentration of vaporized gas generated from the liquor approximate food and drink is further provided, and detected by detecting the alcohol concentration multiple times. When the alcohol concentration exceeds both the predetermined concentration threshold and the difference between the alcohol concentration gradient calculated by the alcohol concentration gradient calculating means and the vaporized gas concentration gradient model is equal to or less than the predetermined threshold, It can be set as the aspect which determines with a subject being a non-drinking state.

  In the drinking level determination apparatus according to the present invention, a difference between an alcohol concentration gradient and a vaporized gas concentration gradient model representing a concentration gradient based on a change over time in the concentration of vaporized gas generated from an alcoholic beverage or drink is equal to or less than a predetermined threshold value. When it is, it determines with a subject being a non-drinking state. For this reason, even if it is determined that the alcohol concentration in the exhalation is high when the subject ingests the alcoholic beverage or similar food, it can be determined that the determination result is not due to drinking. Therefore, it is possible to prevent an erroneous determination in the drinking level determination based on the detection of the alcohol concentration in the exhaled breath, and thus a highly accurate drinking level determination can be performed.

  In addition, the liquor approximate food and drink according to the present invention is different from liquor, but refers to food or drink that produces alcohol or a component similar to alcohol in the human mouth, for example juice such as fruit juice drink, coffee, fermented food system Belongs to kimchi, yogurt, bread, natto, raccoon, raw wasabi, mustard, mint food (mint gum, mint candy), fermented pickles, Nara pickles, potato miso soup, pharmaceuticals Caffeine agents, sleep improving agents, cough stops, denture stabilizers, nutritional drinks, mouth washes and the like can be exemplified.

  Further, the apparatus further comprises an alcohol concentration gradient model storing means for storing an alcohol concentration gradient model based on a change with time of the alcohol concentration in the drinking state, and the difference between the alcohol concentration gradient calculated by the alcohol concentration gradient calculating means and the alcohol concentration gradient model. It can be set as the aspect which determines with a test subject being a drinking state when is below a predetermined threshold value.

  In general, when alcohol is consumed, the change in alcohol concentration with time is small, the alcohol concentration gradient is small, and the concentration gradient tends to be different from that in the case of ingesting alcoholic beverages. For this reason, when the difference between the alcohol concentration gradient and the alcohol concentration gradient model is equal to or less than a predetermined threshold value, it is possible to accurately determine the drinking state by determining that the subject is in the drinking state. .

  Of the alcohol concentrations detected multiple times, of the alcohol concentrations detected by multiple times of alcohol concentration detection, the previously detected alcohol concentration exceeds a predetermined concentration threshold, and the alcohol concentration detected later is predetermined. When the difference between the alcohol concentration gradient calculated by the alcohol concentration gradient calculating means and the alcohol concentration gradient model is equal to or less than a predetermined threshold, the subject is in a drinking state Can be determined.

  When the subject drinks alcohol, the alcohol concentration in the exhalation is in a high state, but thereafter, the exhalation alcohol concentration may temporarily decrease. In this regard, in the drinking level determination apparatus according to the present invention, the alcohol concentration detected earlier exceeds a predetermined concentration threshold, and the alcohol concentration detected later is equal to or lower than the predetermined concentration threshold. When the difference between the alcohol concentration gradient calculated by the concentration gradient calculating means and the alcohol concentration gradient model is equal to or smaller than a predetermined threshold value, the alcohol concentration is detected again. If the alcohol concentration detected earlier exceeds a predetermined concentration threshold and the alcohol concentration detected later is less than or equal to the predetermined concentration threshold, the alcohol concentration detected later is the predetermined concentration threshold. Despite being below the value, it may also be a drinking state. Here, if the difference between the alcohol concentration gradient and the alcohol concentration gradient model is less than or equal to a predetermined threshold value, it is highly likely that the subject is in a drunk state. By doing so, it is possible to accurately determine the drinking level.

  And when the alcohol concentration gradient model storage means for storing the alcohol concentration gradient model based on the change over time of the alcohol concentration during the drinking state, and the subject is the driver of the vehicle, and the driver is determined to be in the drinking state, An interlock means for stopping the running of the vehicle, and detecting the alcohol concentration detected by the alcohol concentration detection multiple times during the operation of the interlock means first. The alcohol concentration gradient calculated by the alcohol concentration gradient calculating means and the alcohol concentration gradient model are determined when the alcohol concentration exceeds the predetermined concentration threshold value and the alcohol concentration detected later is equal to or lower than the predetermined concentration threshold value. Interlock means continue to operate when the difference is less than a predetermined threshold It may be a mode in which.

  As described above, the alcohol concentration detected earlier exceeds the predetermined concentration threshold, the alcohol concentration detected later is equal to or lower than the predetermined concentration threshold, and the alcohol concentration gradient calculating means calculates the alcohol. If the difference between the concentration gradient and the alcohol concentration gradient model is equal to or less than a predetermined threshold, the alcohol concentration may rise again after subsequent detection. In this case, drunk driving by a driver in a drunk state can be suitably prevented by continuing the operation of the interlock means.

  According to the drinking level determination apparatus according to the present invention, it is possible to perform a highly accurate drinking level determination by preventing an erroneous determination in the drinking level determination based on alcohol concentration detection in expiration.

  Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a block diagram of a drinking level determination apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the drinking level determination apparatus according to the present embodiment includes a drinking level determination ECU (Electronic control unit) 1 and an alcohol detection sensor 2. The alcohol detection sensor 2 is connected to the drinking level determination ECU 1. Has been. An interlock circuit 3 is connected to the drinking level determination ECU 1.

  The drinking level determination ECU 1 is a computer mounted on a vehicle, and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface, and the like. The drinking level determination ECU 1 includes an operation threshold value determination unit 11, a malfunction determination unit 12, a food and drink database 13, and a control instruction unit 14.

  The alcohol detection sensor 2 is provided at a position where the breath of the driver who is the subject in the vehicle is blown when the drinking level is determined. Specifically, it is provided in a steering, a rearview mirror, a sun visor and the like. The alcohol detection sensor 2 detects the breath alcohol concentration based on the amount of alcohol contained in the breath discharged by the driver when determining the drinking state. The alcohol detection sensor 2 transmits the detected breath alcohol concentration to the operation threshold value determination unit 11 and the malfunction determination unit 12 in the drinking level determination ECU 1.

  The interlock circuit 3 performs control such as start, continuation, and release of the interlock control based on the interlock control information transmitted from the control instruction unit 14 in the drinking level determination ECU 1. When the interlock control is being performed, control is performed so that the engine of the vehicle is not started, and the engine can be started when the interlock control is released.

  The operation threshold value determination unit 11 stores an alcohol concentration threshold value for performing an interlock control, and includes an expired alcohol concentration transmitted from the alcohol detection sensor 2, and a stored alcohol concentration threshold value. Compare The operation threshold value determination unit 11 performs an operation determination as to whether or not to operate the interlock control based on the comparison result. The operation threshold value determination unit 11 outputs the determined operation determination result of the interlock control to the control instruction unit 14.

  The malfunction determination unit 12 includes a temporary storage unit that temporarily stores the expiration alcohol concentration transmitted from the alcohol detection sensor 2 as the previous expiration alcohol concentration. Based on the previous breath alcohol concentration stored in the temporary storage unit and the current breath alcohol concentration received from the current alcohol detection sensor 2, the malfunction determination unit 12 determines the concentration gradient of the breath alcohol concentration (hereinafter referred to as the “expiration alcohol concentration gradient”). ").

  The food and drink database 13 stores a concentration gradient of vaporized gas generated from liquor approximate food and drink (hereinafter referred to as “vaporized gas concentration gradient”). The food and drink database 13 serves as a vaporized gas concentration gradient model storage means of the present invention, and the vaporized gas concentration gradient serves as a vaporized gas concentration gradient model of the present invention. As alcoholic beverage approximate food and drink, Nara pickles, fruit juice drinks, and the like are assumed, and the concentration gradients of these vaporized gases are stored.

  The malfunction determination unit 12 compares the calculated breath alcohol concentration gradient with the vaporized gas concentration gradient read from the food and beverage database 13 to determine the possibility of malfunction in the drinking determination. The malfunction determination unit 12 outputs a malfunction determination result based on the determination result of the possibility of malfunction to the control instruction unit 14.

  The control instruction unit 14 determines whether or not the interlock control is executed based on the operation determination result output from the operation threshold determination unit 11 and the malfunction determination result output from the malfunction determination unit 12. The control instruction unit 14 transmits interlock control information based on whether or not the interlock control is executed to the interlock circuit 3.

  Moreover, the control instruction | indication part 14 outputs drinking state determination information to the malfunction determination part 12, when it determines with performing interlock control. The malfunction determination unit 12 can store the drinking level determination information in the temporary storage unit, and stores the drinking level determination information when the drinking level determination information is output from the control instruction unit 14.

  Then, the procedure of the drinking level determination process in the drinking level determination apparatus according to the present embodiment will be described. FIG. 2 is a flowchart showing the procedure of the drinking level determination process according to the present embodiment.

  As shown in FIG. 2, in the drinking level determination apparatus according to the present embodiment, first, a breath test of the driver is performed (S1). In the breath test, the alcohol detection sensor 2 detects the breath alcohol concentration from the breath discharged by the driver. The alcohol detection sensor 2 transmits the detected breath alcohol concentration to the operation threshold value determination unit 11 and the malfunction determination unit 12.

  Next, the malfunction determination unit 12 determines whether or not it is determined to be a drinking state in the previous drinking state determination (S2). This determination is made based on whether or not the drinking level determination information output from the control instruction unit 14 is stored in the malfunction determination unit 12. As a result, when it is determined that the previous drinking level determination is not the drinking level, the drinking level determination process is terminated as it is.

  On the other hand, if it is determined in the previous drinking state determination that the person is in the drinking state, the breathing alcohol concentration transmitted from the alcohol detection sensor 2 in the operation threshold value determination unit 11 is the stored alcohol concentration. It is determined whether or not the threshold value is exceeded (S3). As a result, when it is determined that the breath alcohol concentration transmitted from the alcohol detection sensor 2 does not exceed the stored alcohol concentration threshold (below), the interlock control is performed as a non-drinking state. Is not operated and is output to the control instruction unit 14 as an operation determination result. And in the control instruction | indication part 14, the interlock control information which cancels | releases interlock control is transmitted to the interlock circuit 3 (S6), and a drinking state determination process is complete | finished.

  When it is determined that the breath alcohol concentration exceeds the alcohol concentration threshold value, the operation threshold value determination unit 11 determines that the interlock control is to be operated, and the control instruction unit 14 receives the operation determination result. Output. Subsequently, the malfunction determination unit 12 calculates a breath alcohol concentration gradient, which is a concentration gradient between the breath alcohol concentration detected by the previous alcohol detection sensor 2 and the breath alcohol concentration detected by the current alcohol detection sensor 2 (S4). ). Then, the malfunction determination unit 12 determines whether or not the calculated breath alcohol concentration gradient approximates the vaporized gas concentration gradient stored in the food and drink database 13 (S5). Here, whether or not the concentration gradient of the breath alcohol concentration and the concentration gradient of the vaporized gas are approximated is determined by whether or not the difference between the breath alcohol concentration gradient and the vaporized gas concentration gradient is equal to or less than a predetermined threshold value. Is done.

  As a result, if it is determined that the breath alcohol concentration gradient is close to the vaporized gas concentration gradient, the driver is considered to be in a non-drinking state. For this reason, it is determined that the interlock control may cause a malfunction, and is output to the control instruction unit 14 as a malfunction determination result. In the control instruction unit 14, an operation determination result indicating that the interlock control is to be operated is output from the operation threshold determination unit 11, but the interlock control may cause a malfunction from the malfunction determination unit 12. The malfunction determination result is output. For this reason, in the control instruction | indication part 14, the interlock control information which cancels | releases interlock control is transmitted to the interlock circuit 3 (S6), and a drinking state determination process is complete | finished.

  On the other hand, if the malfunction determination unit 12 determines that the breath alcohol concentration gradient does not approximate the vaporized gas concentration gradient, the driver is considered to be in a drunk state. For this reason, it is determined that the interlock control is not malfunctioning, and is output to the control instruction unit 14 as a malfunction determination result. In the control instruction unit 14, an operation determination result indicating that the interlock control is to be operated is output from the operation threshold value determination unit 11, and a malfunction that the interlock control does not cause a malfunction from the malfunction determination unit 12. The determination result is output. For this reason, the interlock control information which performs interlock control is transmitted to the interlock circuit 3 (S7), and the drinking level determination process is terminated. The execution of the interlock control here means that the interlock control is continued when the interlock control is performed, and the interlock control is started when the interlock control is released.

  Comparing the case where the driver drank and the case where the alcohol approximated food / drink was consumed, if the time elapsed since the intake of alcohol or the alcohol approximated food / drink (hereinafter referred to as “target intake”) is short, Common in that the alcohol concentration is high. However, when a certain amount of time has passed since the ingestion of the object, there is a difference in the attenuation of the breath alcohol concentration.

  FIG. 3 shows an example of a change over time in the breath alcohol concentration when an alcohol approximate food or drink is ingested. As shown in FIG. 3, when the alcohol approximate food or drink is ingested, the expired alcohol concentration exceeds the alcohol concentration threshold TH when the elapsed time from the ingestion of the object is short. When a certain amount of time (about 3 minutes) elapses, the expiration alcohol concentration is attenuated, and when the time t13 (t13 <5 minutes) is reached, the expiration alcohol concentration becomes equal to or less than the alcohol concentration threshold value TH. Although not shown, when the driver drinks alcohol, the expired alcohol concentration exceeds the alcohol concentration threshold value TH even when 5 minutes have elapsed.

  Here, it is assumed that when the breath alcohol concentration detected by the breath alcohol concentration detection exceeds the alcohol concentration threshold TH, it is determined that alcohol has been drunk. In this case, if the time t11 when the alcohol detection sensor 2 detects the alcohol is before the time t13, the breath alcohol concentration exceeds the alcohol concentration threshold even when the alcohol approximate food or drink is ingested. It becomes. In addition, when the second breath alcohol concentration detection is performed at time t12 following time t11, if the time t12 is before time t13, the breath alcohol concentration is the alcohol concentration even in the second breath alcohol concentration detection. The threshold will be exceeded. In this case, the breath alcohol concentration exceeds the alcohol concentration threshold value TH in both detections of the breath alcohol concentration twice, and it is determined that alcohol has been drunk in spite of having actually consumed the alcohol approximate food and drink. It will be.

  In this regard, in the drinking state determination processing according to the present embodiment, the alcohol concentration is determined from the previous breath alcohol concentration detected by the first breath alcohol concentration detection and the current breath alcohol concentration detected by the second breath alcohol concentration detection. Seeking the slope. The alcohol concentration gradient shows a tendency to attenuate the breath alcohol concentration, and is different between when alcohol is consumed and when alcohol-like food is consumed. Specifically, when the alcohol approximated food / drink is ingested, the alcohol concentration gradient becomes larger than when the alcohol is drunk.

  Then, when the alcohol concentration gradient is obtained, the alcohol concentration gradient is compared with the vaporized gas concentration gradient. The interlock control due to the malfunction based on is canceled. For this reason, it is possible to prevent an erroneous determination in the drinking state determination by the alcohol approximate food and drink, and thus it is possible to perform a highly accurate drinking state determination.

  Next, a second embodiment of the present invention will be described. The drinking level determination apparatus according to the present embodiment includes a drinking level determination ECU 20, and the drinking level determination ECU 20 includes an operation continuation determination unit 21 and a drinking level database 22. Moreover, the alcohol detection sensor 2 similar to the said 1st Embodiment, the action | operation threshold value determination part 11, the control instruction | indication part 14, and the interlock circuit 3 are provided.

  The operation continuation determination unit 21 includes a temporary storage unit that temporarily stores the expiration alcohol concentration transmitted from the alcohol detection sensor 2 as the previous expiration alcohol concentration. The operation continuation determination unit 21 obtains an expiration alcohol concentration gradient based on the previous expiration alcohol concentration stored in the temporary storage unit and the current expiration alcohol concentration received from the current alcohol detection sensor 2. The drinking level database 22 stores a drinking level alcohol concentration gradient based on a change with time of the alcohol concentration gradient in the drinking level. The drinking level database 22 serves as the alcohol concentration gradient model storage means of the present invention, and the drinking level alcohol concentration gradient serves as the alcohol concentration gradient model of the present invention.

  The operation continuation determining unit 21 compares the calculated breath alcohol concentration gradient with the drinking alcohol concentration gradient read from the drinking alcohol database 22, and determines whether or not to continue the interlock control. The operation continuation determination unit 21 outputs a continuation determination result based on the determination result of whether or not to continue the interlock control to the control instruction unit 14.

  Then, the procedure of the drinking level determination process in the drinking level determination apparatus according to the present embodiment will be described. FIG. 5 is a flowchart showing the procedure of the drinking level determination process according to the present embodiment.

  As shown in FIG. 5, in the drinking level determination device according to the present embodiment, first, the driver's breath test is performed (S11), and whether or not the operation continuation determination unit 21 determines that the drinking level is determined in the previous drinking level determination. Is determined (S12). As a result, if it is determined in the previous drinking state determination that it is not the drinking state, the drinking state determination process is terminated as it is. Further, when it is determined that the person is in the drinking state in the previous drinking state determination, the breath alcohol concentration transmitted from the alcohol detection sensor 2 is the alcohol concentration threshold stored in the operation threshold value determination unit 11. It is determined whether or not the value is exceeded (S13). Up to this point, the same procedure as in the first embodiment is performed.

  Then, as a result of the determination in step S13, when it is determined that the breath alcohol concentration transmitted from the alcohol detection sensor 2 exceeds the alcohol concentration threshold stored in the operation threshold determination unit 11, It is determined that the interlock control is continued, and the operation determination result is output to the control instruction unit 14. And in the control instruction | indication part 14, the interlock control information which continues interlock control is transmitted to the interlock circuit 3 (S14), and a drinking state determination process is complete | finished.

  If it is determined that the breath alcohol concentration does not exceed the alcohol concentration threshold value (below), the operation continuation determination unit 21 detects the breath alcohol concentration detected by the previous alcohol detection sensor 2 and the current alcohol detection. An alcohol concentration gradient that is a concentration gradient with respect to the breath alcohol concentration detected by the sensor 2 is calculated (S15).

  Thereafter, the operation continuation determining unit 21 determines whether or not the calculated breath alcohol concentration gradient approximates the drinking alcohol concentration gradient stored in the drinking alcohol database 22 (S16). Whether or not the breath alcohol concentration gradient and the drinking alcohol concentration gradient are approximated is determined by whether or not the difference between the breath alcohol concentration gradient and the drinking alcohol concentration gradient is equal to or less than a predetermined threshold value.

  As a result, if it is determined that the breath alcohol concentration gradient is close to the alcohol concentration gradient, the driver is considered to be in the drinking state. For this reason, it is determined that the driver is in a drinking state, it is determined that the interlock control is to be continued, and the result is output to the control instruction unit 14 as a continuation determination result. In the control instruction unit 14, an operation determination result indicating that the interlock control is to be operated is output from the operation threshold value determination unit 11, and a continuation determination result indicating that the interlock control is to be continued is output from the operation continuation determination unit 21. Is done. For this reason, in the control instruction | indication part 14, the interlock control information which continues interlock control is transmitted to the interlock circuit 3 (S14), and a drinking state determination process is complete | finished.

  On the other hand, when the malfunction determination unit 12 determines that the breath alcohol concentration gradient and the vaporized gas concentration gradient are not approximate, the driver is considered to be in a non-drinking state. For this reason, it is determined that the driver is in a non-drinking state, it is determined that the interlock control is not continued, and the continuation determination result is output to the control instruction unit 14. In the control instruction unit 14, an operation determination result indicating that the interlock control is operated is output from the operation threshold determination unit 11, but a continuation determination result indicating that the interlock control is not continued is output from the operation continuation determination unit 21. Is output. For this reason, the interlock control information which cancels | releases interlock control is transmitted to the interlock circuit 3 (S17), and a drinking state determination process is complete | finished.

  When the driver drinks, the breath alcohol concentration is high, but the alcohol component disappears from the mouth and the breath alcohol concentration may tend to decrease temporarily until the alcohol is broken down into the blood. . FIG. 6 shows an example of the change over time in the breath alcohol concentration when alcohol is used.

  As shown in FIG. 6, when alcohol is consumed, the breath alcohol concentration rapidly rises between the time of drinking and time t21. Then, until the time t22, the breath alcohol concentration is stable in a high state. Thereafter, the alcohol in the oral cavity disappears, and the alcohol concentration in the oral cavity decreases.

  On the other hand, the ingested alcohol component is broken down into the blood in the body, so that the alcohol contained in the exhaled breath is small and the alcohol component contained in the exhaled breath exhausted from the lung is also small. As a result, the alcohol concentration in the oral cavity and the alcohol concentration in the exhaled breath discharged from the lung are both low, and thus the expired alcohol concentration continues to decrease until time t23.

  Thereafter, alcohol decomposed in the blood is contained in exhaled air via the lungs. For this reason, the breath alcohol concentration rises again until time t24. After time t24, the alcohol in the blood is decomposed over time, and the breath alcohol concentration gradually decreases.

  Here, between the time t23 and the time t24, the breath alcohol concentration may once fall below the alcohol concentration threshold TH. For this reason, for example, when the expired alcohol concentration is detected at the stage of time t32, it may be erroneously determined that the alcohol is not in the drinking state although it is actually in the drinking state.

  In this regard, in the drinking level determination device 20 according to the present embodiment, even when it is determined at time t32 that the breath alcohol concentration is equal to or lower than the alcohol concentration threshold value TH, the breath alcohol concentration is the alcohol concentration at the previous time t31. If it is determined that the threshold value TH is exceeded, an expiration alcohol concentration gradient is calculated from the expiration alcohol concentration at time t31 and the expiration alcohol concentration at time t32. When the calculated breath alcohol concentration approximates the drinking alcohol concentration, it is determined that the person is in a drinking state.

  For this reason, to prevent misjudgment when the time when the breath alcohol concentration is detected is in a state where the alcohol is being decomposed into the blood and the breath alcohol concentration is low until the alcohol in the oral cavity disappears Can do. As a result, it is possible to determine the drinking level with high accuracy.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in each said embodiment, although it uses for the drinking level determination apparatus for performing interlock control, it can also be used for another drinking level determination apparatus. In the above embodiment, the breath alcohol concentration is detected twice. However, the breath alcohol concentration may be detected three times or more.

  Furthermore, it can also be set as the drinking state determination apparatus which combined the said 1st Embodiment and 2nd Embodiment. In the second embodiment, when it is determined that the breath alcohol concentration gradient is close to the drinking alcohol concentration gradient when the breath alcohol concentration does not exceed the alcohol concentration threshold, the driver Is determined to be drinking. On the other hand, when the breath alcohol concentration does not exceed the alcohol concentration threshold, the driver is uniformly determined to be in a non-drinking state, and the previous breath alcohol concentration exceeds the alcohol concentration threshold. When it is determined that the breath alcohol concentration gradient is close to the drinking alcohol concentration gradient when the breath alcohol concentration is equal to or lower than the alcohol concentration, the interlock control can be continued.

It is a block block diagram of the drinking level determination apparatus which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the drinking level determination apparatus which concerns on 1st Embodiment. It is a graph which shows an example of a time-dependent change of the expiration alcohol concentration at the time of ingesting alcohol approximate food and drink. It is a block block diagram of the drinking level determination apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the process sequence of the drinking level determination apparatus which concerns on 2nd Embodiment. It is a graph which shows an example of the time-dependent change of the expiration alcohol concentration at the time of drinking.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drinking state determination ECU, 2 ... Alcohol detection sensor, 3 ... Interlock circuit, 11 ... Operation | movement threshold value determination part, 12 ... Malfunction determination part, 13 ... Food and drink database, 14 ... Control instruction | indication part, 20 ... Drinking State determination device, 21 ... operation continuation determination unit, 22 ... drinking level database.

Claims (1)

A drinking state determination device that detects alcohol concentration in the breath of a subject and determines the drinking state of the subject based on the detected alcohol concentration,
Based on the alcohol concentration detected by the plurality of alcohol concentration detection, comprising an alcohol concentration gradient calculating means for calculating the alcohol concentration gradient based on temporal change in the alcohol concentration,
Based on the alcohol concentration and the alcohol concentration gradient, determine the drinking state of the subject ,
A vaporized gas concentration gradient model storage means for storing a vaporized gas concentration gradient model representing a concentration gradient based on a change with time of the concentration of vaporized gas generated from the liquor approximate food and drink;
All of the alcohol concentrations detected by the plurality of times of alcohol concentration detection exceed a predetermined concentration threshold, and the difference between the alcohol concentration gradient calculated by the alcohol concentration gradient calculating means and the vaporized gas concentration gradient model is predetermined. A drinking level determination device , wherein the subject is determined to be in a non-drinking state when the threshold is equal to or less than a threshold value .

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