JP2009281822A - Alcohol detection device, and vehicle equipped with alcohol detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alcohol detection device provided on a vehicle for detecting highly accurately alcohol contained in exhalation of a driver. <P>SOLUTION: A frequency change caused by alcohol is clarified by constituting this detection device to have: a quartz oscillator having a vibration domain for alcohol detection, wherein an adsorption layer for adsorbing alcohol is formed on its surface, and a characteristic frequency is changed by alcohol adsorption onto the adsorption layer, and a vibration domain for reference provided on a domain different from the vibration domain for detection, on which alcohol is not adsorbed; and a data generation means for verification including a means for generating time series data of a difference value between each frequency, based on a frequency corresponding to oscillation output from the vibration domain for detection and a frequency corresponding to oscillation output from the vibration domain for reference, and a means for removing a pulse flow part included in the time series data by regarding it as a noise. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an alcohol detection device mounted on a vehicle such as an automobile and a vehicle including the alcohol detection device.

  Despite measures that have been taken, such as strengthening penalties and crackdowns, accidents caused by vehicles such as cars due to drunk driving by drivers are inexhaustible, leading to serious accidents such as fatal accidents. It is. For this reason, it is considered to install an alcohol interlock device in the vehicle that determines whether or not the driver is in a drunk state and prevents the engine from starting if the driver is in a drunk state. ing.

  There is an exhalation-type alcohol sensor composed of a semiconductor sensor as a sensor for detecting alcohol that is an indicator of the drinking level, and this alcohol sensor is the alcohol contained in the exhalation when the driver blows on a predetermined part. It detects odor. It is conceivable to configure the alcohol interlock device using such an alcohol sensor, but this alcohol sensor may not be sufficiently sensitive to alcohol when mounted on a vehicle. If a person does not actively blow on a predetermined part of the sensor, it is difficult to accurately detect alcohol, and the acceptability to the user is low. For this reason, this alcohol sensor is often used only for the purpose of measuring the concentration of alcohol odor and acquiring the data.

  Thus, it has been studied to detect alcohol by providing a crystal sensor using a crystal resonator formed of a crystal piece in a vehicle. This crystal sensor adsorbs alcohol to the crystal oscillator constituting the crystal oscillation circuit, and senses the alcohol by capturing changes in time series data of the oscillation frequency (resonance frequency). It is considered that the sensitivity to alcohol odor can be increased by using it.

  However, when the vehicle runs on a rough road, the impact received by the car body is transmitted to the crystal unit, the oscillation of the crystal unit is affected, the oscillation frequency fluctuates, and the time series data shows a steep change temporarily. The pulsating current may be generated as noise. And if generation | occurrence | production of a pulsating flow continues, there exists a possibility that the frequency change by alcohol may not be caught. Specifically, for example, when the determination unit is configured to determine whether or not the driver is in a drunk state when the frequency changes in a certain range for a predetermined time in the time series data, this frequency is set. If the frequency exceeds the range due to the fluctuation, the determination means may determine that the driver is drinking but not drinking.

  Also, when the sensitivity to alcohol is increased in this way, if the driver is not drinking and the companion who gets into the vehicle is drinking, the odor of the companion is detected and the engine is detected. There is a possibility that a case may occur that does not start. Such operational problems are also factors that hinder the provision of an alcohol interlock device.

Incidentally, Patent Document 1 describes a method of performing an interlock using an alcohol sensor, but does not describe the above problem. Patent Document 2 describes a sensing device using a crystal sensor that forms a region that individually vibrates in different regions of a crystal piece and suppresses the influence of vibration by calculating a difference in frequency between the vibration regions. . A crystal resonator has a temperature characteristic that its oscillation frequency changes depending on the ambient temperature, and it is effective to adopt the above configuration in order to avoid the influence of this temperature characteristic. However, as described above, an automobile has a bad road. In some cases, different stresses are applied to the respective vibration regions of the crystal piece, and different frequency changes may occur. Therefore, this configuration is insufficient to detect alcohol under adverse conditions in the vehicle.
JP2004-249847 JP 2006-33195 A

  The present invention has been made based on such circumstances, and an object of the present invention is to provide an alcohol detection device that is provided in a vehicle and accurately detects alcohol contained in a driver's breath and a detection result of the alcohol detection device. And a vehicle whose travel is restricted by the operation of the driver.

The alcohol detection device of the present invention is provided in a vehicle, and in the alcohol detection device for detecting alcohol contained in the breath of the driver of the vehicle,
An adsorption layer for adsorbing the alcohol is formed on the surface, and a vibration region for alcohol detection in which the natural frequency changes due to the adsorption of alcohol to the adsorption layer is different from the vibration region for detection. A first crystal resonator provided with a reference vibration region that is provided and does not adsorb the alcohol;
Oscillation means for independently oscillating the vibration region for detection and the vibration region for reference of the first crystal unit;
The difference between these frequencies based on the frequency corresponding to the oscillation output of the vibration region for detection in the first crystal resonator and the frequency corresponding to the oscillation output of the reference vibration region in the first crystal resonator. Data creation means for verification including means for creating time-series data of values, and means for removing the pulsating flow portion included in the time-series data as noise.
It is provided with.
The verification data creation means corresponds to the means for creating time-series data of the frequency corresponding to the oscillation output of the detection vibration area instead of the above configuration, and the oscillation output of the reference vibration area. There may be provided means for creating time series data of the frequency to be processed and means for removing the pulsating flow portion included in each time series data as noise.

An adsorption layer is formed on the surface to adsorb alcohol contained in the exhalation of passengers other than the driver,
A vibration region for alcohol detection in which the natural frequency changes due to the adsorption of alcohol to the adsorption layer, and a reference vibration region that is provided in a region different from the vibration region for detection and does not adsorb the alcohol. A second crystal unit comprising:
Oscillation means for independently oscillating the vibration region for detection and the vibration region for reference of the second crystal unit;
The difference between these frequencies based on the frequency corresponding to the oscillation output of the vibration region for detection in the second crystal resonator and the frequency corresponding to the oscillation output of the reference vibration region in the second crystal resonator. Data generating means for comparison including means for generating time-series data of values, and means for removing the pulsating flow portion included in the time-series data as noise.
Detection means for detecting alcohol based on the comparison data and the verification data;
The comparison data creation means may comprise means for creating time series data of a frequency corresponding to the oscillation output of the vibration region for detection instead of the above configuration, and the reference data There may be provided means for creating time series data of frequencies corresponding to the oscillation output of the vibration region, and means for removing the pulsating flow portion included in each time series data as noise.

  The pulsating portion is removed by, for example, taking a moving average with respect to time series data.

The vehicle of the present invention is a vehicle equipped with an alcohol detection device for detecting alcohol contained in the expiration of the driver.
Based on the detection result of the above-described alcohol detection device and the detection means, a control unit for limiting the travel of the vehicle by the operation of the driver;
It is provided with.

  The alcohol detection device according to the present invention includes a vibration region for alcohol detection in which an adsorption layer for adsorbing alcohol in the breath of a driver is formed, and the natural frequency changes due to the adsorption, and a reference for not adsorbing the alcohol. A crystal resonator having a vibration region for reference (for reference), and a frequency corresponding to the oscillation output of the vibration region for detection in the crystal resonator and the oscillation output of the reference vibration region in the crystal resonator Based on the corresponding frequency, time-series data of the difference value of these frequencies is created, and the pulsating portion included in the time-series data is regarded as noise and removed. Therefore, since the change due to the alcohol in the verification time-series data can be suppressed from being confused by the pulsating flow portion, this change can be clearly understood, and the deterioration of the alcohol detection accuracy can be suppressed.

  Hereinafter, the alcohol detection device according to the present embodiment will be described. FIGS. 1A and 1B show an example of the appearance of an automobile 1 on which an alcohol detection device 10 is mounted. The alcohol detection device 10 includes sensor units 2A and 2B including crystal resonators, And a processing unit 4 that calculates the frequency from the sensor units 2A and 2B connected to the subsequent stage. The processing unit 4 is connected to a control unit 5 that controls the operation of the engine of the automobile 1 as will be described later.

  The sensor units 2A and 2B are provided above the driver seat 11 and the passenger seat 12, respectively, and these alcohols are included in the breaths of the driver sitting in the driver seat 11 and the assistant sitting in the passenger seat 12, respectively. Detect odors. The sensor units 2A and 2B are configured in the same manner, and the configuration of the sensor unit 2A is shown as a representative in FIGS. It is preferable to provide the sensor units 2A and 2B at positions as close as possible to the driver and the assistant in order to reliably detect the alcohol in the breath.

  The sensor unit 2 </ b> A includes a package 21 made of, for example, ceramics whose upper side is opened, a substrate 22 provided in the package 21, and the crystal unit 3. The substrate 22 is provided with a through hole 23, for example, and the crystal unit 3 is provided so as to close the through hole. Thereby, the crystal unit 3 is configured as, for example, a Langevin type crystal unit whose back surface is in contact with the sealed space 24 formed by the surface of the package 21 and the through hole 23 and whose surface is in contact with the atmosphere in the vehicle. ing. Note that a sensor including a crystal resonator may not be provided with a through hole, and is not limited to a Langevin type crystal resonator.

  The crystal unit 3 is composed of a circular crystal piece 31 formed by, for example, AT cutting, and electrodes 32, 33, 34, and 35 made of, for example, gold. 3A, 3B, and 3C show the front surface, the back surface, and the side surface of the crystal resonator 3, respectively. The electrodes 32 to 35 are each formed in a rectangular shape in each semicircular region when the front and back surfaces of the crystal piece 31 are divided along the diametrical direction, and a part of the circumference of the rectangle is outside the crystal piece 31. It is formed so that it can be pulled out toward.

  In each of the electrodes 32 to 35 of the crystal resonator 3, the portions that are drawn outward of the crystal piece 31 are bonded to the electrodes 25 a to 25 d provided on the substrate 22 through the conductive adhesive 26. The electrodes 25a to 25d are electrically connected to electrodes 29a to 29d provided on the back surface of the package 21 through conductive paths 27 and 28 provided in the substrate 22 and the package 21, respectively. Accordingly, the electrodes 32 to 35 of the crystal unit 3 are electrically connected to the electrodes 29a to 29d, respectively.

  Within the surface of the crystal piece 31, the electrodes 32 and 33 and the electrodes 34 and 35 are opposed to each other. In the crystal piece 31, a region sandwiched between the electrodes 32 and 33 and a region sandwiched between the electrodes 34 and 35 are configured as vibration regions 3A and 3B. The vibration region 3A can be vibrated independently by the electrodes 32 and 33, and the vibration region 3B can be vibrated independently by the electrodes 34 and 35, thereby outputting a frequency signal. Each electrode 32 to 35 has a thickness that is slightly different from each other within a range that does not deviate from the purpose of making the frequency temperature characteristics uniform, and the oscillation frequency of the main mode in each vibration region is varied by 50 kHz, for example. In this example, the vibration area 3A is configured as a reference vibration area, and the vibration area 3B is configured as an alcohol detection vibration area.

  That is, the crystal resonator 3 is configured such that one crystal piece 31 has the function of two crystal resonators, and the vibration regions 3A and 3B are formed in a common crystal piece 31. Therefore, it is possible to obtain frequency temperature characteristics in which the variation amounts of the oscillation frequencies output from the respective vibration regions 3A and 3B when the ambient temperature changes can be obtained, and the frequency received from the vibration received from the vehicle body of the automobile 1 As for the amount of change, the difference can be suppressed by configuring each vibration region in one crystal piece 31 in this way.

  For example, as shown in FIG. 4A, the electrode 32 configured to be in contact with the atmosphere in the vehicle in the vibration region 3A has an adsorption film (sensitive film) that does not react with the alcohol 71 contained in the atmosphere in the vehicle 1. A block layer 72, which is a non-sensitive film made of a different dielectric, is formed. The block layer 72 serves to prevent a change in the oscillation frequency “F1” output from the vibration region 3 </ b> A due to the adsorption of the alcohol 71 onto the surface of the electrode 32. The electrode 32 may be exposed without being covered with the block layer 72, but is preferably provided as such a block layer 72 in order to more reliably suppress the adsorption of the alcohol 71 to the electrode 32.

  Further, for example, a polymer such as polystyrene is bonded to the electrode 34 configured to be in contact with the atmosphere in the vehicle in the vibration region 3B by selectively chemically reacting with the alcohol 71 as shown in FIG. 4B, for example. An adsorption layer 73 which is a sensitive film (adsorption film) made of a dielectric material obtained by adding a charge to a system material is provided. Using the mass load effect caused by the alcohol 71 adsorbed on the adsorption layer 73, the oscillation frequency output from the vibration region 3B can be changed, and the changed oscillation frequency F2 can be extracted. After the adsorbed layer 73 adsorbs the alcohol 71, the adsorbed alcohol 71 is separated from the adsorbed layer 73 by being exposed to an air atmosphere having a low alcohol concentration, and is output from the vibration region 3B. Changes.

  Here, since the first vibration region 3A and the second vibration region 3B provided in the crystal unit 3 are placed in a common atmosphere in the sensor unit 2A, the temperature conditions in which the respective regions 25a and 25b are placed. Are almost identical. Since these regions 25a and 25b are provided on the common crystal piece 31, the oscillation frequency “F1” output from the vibration region 3A and the oscillation frequency “F2” output from the vibration region 3B are mutually different. The frequency temperature characteristics are almost the same.

  Although the sensor unit 2A provided on the driver's seat 11 side has been described, the sensor unit 2B provided on the passenger seat 12 side is configured in the same manner as the sensor unit 2A, and the same crystal unit 3 as the sensor unit 2A. It has. Hereinafter, for convenience, a region corresponding to the vibration region 3A is a vibration region 3C, a region corresponding to the vibration region 3B is a vibration region 3D, and frequencies output from the vibration regions 3C and 3D are F3 and F4. Similarly to the oscillation frequencies “F1” and “F2”, the oscillation frequencies “F3” and “F4” output from the vibration regions 3C and 3D exhibit frequency temperature characteristics that are substantially coincident with each other.

  FIG. 5 is a block diagram of the alcohol detection device 10. The processing unit 4 connected to the sensor units 2A and 2B will be described with reference to this figure. The processing unit 4 includes oscillation circuits 41A to 41D, switches 43 and 45, measurement circuit units 44 and 46, and a calculation unit 5. The oscillation circuits 41A to 41D are provided in the subsequent stage of the sensor unit 2A and the subsequent stage of the sensor unit 2B, and the oscillation regions 3A to 3D oscillate by the oscillation circuits 41A to 41D.

  At the subsequent stage of the oscillation circuits 41A and 41B, a switch section 43 is provided for sequentially taking output signals from the respective channels of the sensor section 2A into the subsequent measurement circuit section 44. The switch unit 43 plays a role of capturing the frequency signals from the two oscillation circuits 41A and 41B in a time-sharing manner, and can obtain the oscillation frequency of each channel in parallel. For example, one second is divided into n (n is an even number), and the oscillation frequency of each channel is sequentially obtained by a process of 1 / n second, so that it is not strictly measured simultaneously, but at least in one second. Since the frequency is acquired once or more, the frequency of each channel can be acquired substantially simultaneously. Similarly to the switch unit 43, the switch unit 45 provided in the subsequent stage of the oscillation circuits 41C and 41D also has a function of sequentially taking in the frequency signal of each channel of the sensor unit 2B into the measurement circuit unit 46 in the subsequent stage.

  In this example, the measurement circuit units 44 and 46 play a role of digitally processing a frequency signal as an input signal and measuring an oscillation frequency of each channel.

  Next, the calculation unit 5 provided in the subsequent stage of the measurement circuit units 44 and 46 will be described. The arithmetic unit 5 includes a bus 51, which includes a CPU (central processing unit) 52, a data processing program 53, a storage unit that stores a noise removal program 54, a first memory 55, a second memory 56, The third memory 57 and the above-described measurement circuit units 44 and 46 are connected.

  The data processing program 53 plays a role of acquiring time series data related to the oscillation frequency of each channel based on the signals output from the measurement circuit units 44 and 46 and storing them in the first memory 55. Simultaneously with this data acquisition operation, the difference value “F1-F2”, the oscillation frequency “F3”, and the oscillation frequency “F4” of the time series data between the oscillation frequency “F1” and the oscillation frequency “F2” in the same time zone. The difference value “F3-F4” of each time-series data is calculated, and the difference “(F1-F2) − (F1-F2)” between these data “F1-F2” and “F3-F4” in the same time zone is calculated. F3-F4) "is calculated to obtain time series data of these difference values. The acquired time series data is stored in the second memory 56.

  The noise removal program 54 performs, for example, a predetermined time point on each time series data of “F1-F2”, “F3-F4”, and “(F1-F2)-(F3-F4)” stored in the second memory. A moving average of a plurality of continuous data up to a predetermined time slightly going back in the past is sequentially calculated every time the latest data is obtained for these time series data, and these time series data “F1-F2”, “ F3-F4 "," (F1-F2)-(F3-F4) "processed time series data" (F1-F2) '"," (F3-F4)' "," {( F1-F2)-(F3-F4)} '"is stored in the third memory 57.

  6 and 7, the oscillation frequencies “F1” and “F2”, the difference value data “F1 to F2” and “(F1 to F2) ′”, which are processed by the measurement circuit unit 46 and output to the calculation unit 5. An example is shown. The time t1 in the graph is the time when the driver drinks in the vehicle, the exhalation of the driver flows to the sensor unit 2A, and the alcohol in the exhalation is adsorbed by the adsorption layer 73 of the sensor unit 2A. Time t2 is a time when the driver gets out of the car, the exhalation does not flow to the sensor unit 2A, the alcohol concentration around the sensor unit 2A decreases, and the alcohol leaves the adsorption layer 73.

  As described above, in the alcohol detection device 10, the vibration regions 3A and 3B are formed on the same crystal piece 31, so that the vibration regions 3A and 3B are added to the case where the vibration regions are formed on separate crystal pieces. However, when the vehicle 1 is traveling on a rough road or idling, the vehicle body vibrates violently, and the impact applied to each vibration region 3A, 3B is different from each other. As shown in FIGS. 6A and 6B, due to the impact, pulsating flows having different magnitudes may appear at the same time in the time series data of the oscillation frequencies “F1” and “F2”.

  Between times t1 and t2, the oscillation frequency “F1” is originally maintained at a lower frequency than before time t1 and after time t2 due to the adsorption of alcohol, but as described above, the oscillation frequencies “F1”, “F2” are maintained. As a result of the occurrence of the pulsating flow in the time series data of “”, the pulsating flow remains as noise in “F1-F2” which is the difference data of these frequencies as shown in FIG. From the difference data “F1-F2”, there is a case where the frequency change between the vibration regions 3A and 3B due to alcohol cannot be detected due to noise. Therefore, by calculating the moving average of “F1-F2”, time series data “(F1-F2) ′” is output. In this “(F1-F2) ′”, the pulsating portion due to the vibration is removed or reduced as noise, so as shown in FIG. 6D, the vibration in the vibration region 3A due to alcohol in the sensor unit 2A. The fluctuation of the frequency in the region 3B is clear.

  In this example, the sensor unit 2B uses the same crystal unit 3 as the sensor unit 2A, and the vibration region 3B of the sensor unit 2A and the vibration region 3D of the sensor unit 2B have the same alcohol concentration in the surrounding atmosphere. When it changes, the frequency of the oscillating signal changes in substantially the same way. As in the case where the shocks applied to the vibration regions 3A and 3B are different from each other, the shocks applied to the vibration regions 3C and 3D are different from each other, so that the oscillation frequency “F3” is shown in FIGS. 7A and 7B, respectively. In the time series data of “F4”, similarly to the time series data of the oscillation frequencies “F1” and “F2”, pulsating currents having different magnitudes appear at the same time, and the time series data “F3-F4” In some cases, the pulsating flow may remain as noise. Therefore, in this example, in the same manner as calculating “(F1-F2) ′” from “(F1-F2)”, a moving average of “F3-F4” shown in FIG. 7 (d), the time series data “(F3-F4) ′” in which the pulsating portion is removed or reduced as noise is output, and the variation in the frequency of the vibration region 3D with respect to the vibration region 3C due to alcohol is clarified. I have to. In the example shown in the figure, the assistant is not drinking, and the driver's breath slightly flows to the sensor section 2B on the passenger seat side, and the alcohol in the breath is only attached to the sensor section 2B. The frequency change amount of (F3-F4) ′ ”is smaller than the change amount of“ (F1-F2) ′ ”.

  In addition, by calculating the moving average “{(F1-F2) − (F3-F4)} ′” of “{(F1-F2) − (F3-F4)}”, the vibration regions of the sensor unit 2A And the difference between the vibration regions of the sensor unit 2B, that is, in which of the sensor units 2A and 2B is adsorbed more alcohol. FIGS. 8A and 8B are “{(F1-F2) − (F3-F4)}”, “{(F1-F2)” calculated based on F1 to F4 shown in FIGS. -(F3-F4)} '". Then, as described later, the control unit 6 performs time-series data “(F1-F2) ′”, “(F3-F4) ′”, “{(F1-F2)-(F3-F4)} ′” of these frequencies. The operation of the engine is controlled based on the above.

  For example, a control unit 6 including a computer is connected to the bus 51 of the data processing unit 5. Based on the time series data (F1-F2) ′, (F3-F4) ′ and {(F1-F2) − (F3-F4)} ′ in which the noise is reduced, the control unit 6 will be described later. It is determined whether or not the driver is in a drinking state, and the determination result of the drinking state is displayed on the display unit 61 constituted by a display or the like connected to the control unit 6 together with each time series data.

  The controller 61 includes, for example, a speed limiter that limits the speed of the automobile 1 and is connected to an engine controller 62 for controlling the operation of the engine. A signal corresponding to the operating state is output from the engine controller 62 to the control unit 6, and the control unit 6 controls the engine controller 62 based on the signal and a determination result as to whether or not the driver is in a drinking state. Is output and the running speed of the automobile 1 is decreased by suppressing the operation of the engine in operation, and then the automobile 1 is stopped or maintained in a stopped state to restrict the running of the automobile 1 by the driver's operation. To do. In addition, when the control unit 6 determines that the driver is in a drinking state, the control unit 6 transmits a signal to the alarm generation unit 63, and the alarm generation unit 63 receiving the signal sounds an alarm in the vehicle.

  In addition, a key detection unit 64 is connected to the control unit 6. The key detection unit 64 includes position detection means for detecting the position of the key of the automobile. When the key is brought into the vehicle from the outside of the vehicle, the key detection unit 64 transmits an electric signal corresponding to the key to the control unit 6, For example, the control unit 6 that receives the signal turns on a power switch (not shown) of the processing unit 4 to activate the processing unit 4, and the oscillation circuits 3A to 3D oscillate by the oscillation circuits 41A to 41D. And the frequency measurement starts. On the contrary, when the key is taken out of the vehicle from the inside of the vehicle, the key detection unit 64 transmits an electric signal corresponding to the key to the control unit 6, and the control unit 6 turns off the power switch of the processing unit 4 to cause each oscillation. The oscillation of each of the vibration areas 3A to 3D and the switching of the switches 43 and 44 by the circuits 41A to 41D are stopped. Having such a so-called standby function is preferable because power consumption can be reduced compared to a case where the vibration region constantly oscillates.

  Next, a procedure for detecting an alcohol odor in the automobile 1 will be described. First, for example, the driver brings the key of the automobile 1 into the vehicle, the key detection unit 64 detects it, and transmits an electric signal to the control unit 6. The control unit 6 activates the processing unit 4, and the vibration regions 3A and 3B of the sensor unit 2A and the vibration regions 3C and 3D of the sensor unit 2B start to oscillate. The frequency signals output from the vibration regions 3A and 3B and the frequency signals output from the vibration regions 3C and 3D are time-divided and taken into the measurement circuit units 44 and 46, respectively, and A / D converted. Digital values are signal processed. The frequencies “F1 and F2” are extracted from the frequency signals of the vibration areas 3A and 3B, and these frequencies are stored in the first memory 55 almost simultaneously (for example, shifted by ½ second) and the vibration area. The frequency “F3, F4” is extracted from the 3A and 3B frequency signals, and the operation of storing these frequencies in the first memory 68 substantially simultaneously (for example, by ½ second) is continued.

  When a driver sits in the driver seat 11 and an assistant sits in the passenger seat, the exhaled air flows to the sensor unit 2A and the sensor unit 2B. When the driver's breath contains alcohol, the alcohol is adsorbed to the adsorption layer 73 of the vibration region 3B of the sensor unit 2A, and the frequency “F2” output from the vibration region 3B due to the mass load effect. Will drop. Similarly, when alcohol is contained in the breath of the assistant, the alcohol is adsorbed on the adsorption layer 73 of the sensor unit 2B, and the frequency “F4” output from the vibration region 3D is reduced due to the mass load effect. The more alcohol contained in the exhaled breath, the more alcohol adsorbed on the adsorbing layer 73 and the greater the frequency drop. That is, since the alcohol concentration of exhalation corresponds to a decrease in the frequency of each of the vibration regions 3B and 3D, it can be determined whether or not the driver is in a drinking state based on the decrease in the frequency.

  The time-series data of the frequencies output from the vibration regions 3A to 3D in this way are stored in the first memory 55, and the difference between the frequency “F2” and the frequency “F1” and the frequencies “F3” and “F4”. The time series data “F1-F2” and “F3-F4” of these differences are stored in the second memory 56. Further, simultaneously with these “F1-F2” and “F3-F4”, the time series data “{(F1-F2) − (F3-F4)}” of the frequency difference between the vibration regions 3A and 3B is the second. Stored in the memory 56.

  The frequency of these differences may be obtained at the timing when the frequencies from the respective vibration regions are sequentially taken into the calculation unit 5. For example, in the case of obtaining “F1-F2”, the frequency “F1” of the vibration region 3A. Then, after the frequency “F2” of the vibration region 3B is captured, “F2” is subtracted from “F1” and the difference is written to the second memory 56. After acquiring the series data, time series data of the difference may be created by matching the time axes of these data.

  The processing unit 4 continues to create the time-series data “F1-F2”, “F3-F4”, “{(F1-F2) − (F3-F4)}” of the difference, while the time-series data includes predetermined data. The time-series data “(F1-F2) ′”, “(F3-F4) ′” and “{(F1) from which noise is removed by sequentially calculating a moving average of a plurality of continuous data traced back to the past from the time of -F2)-(F3-F4)} '", and these data are stored in the third memory 57 and displayed on the display unit 61.

  The controller 6 calculates the time series data “(F1-F2) ′”, “(F3-F4) ′” and “{(F1-F2)-(F3-F4)} ′” in this way. Whether or not the driver is drinking is determined according to the flowchart shown in FIG. First, the control unit 6 preliminarily stores “(F1-F2) ′” stored in the third storage unit 57 in advance for a predetermined period of about 30 seconds from the time when the latest data is obtained. It is determined whether or not the set first reference value or more is maintained (step 1). The first reference value is a numerical value that serves as an index as to whether or not the driver is drinking alcohol. However, since the sensor units 2A and 2B are provided in the same vehicle atmosphere, the driver is drinking alcohol. It is also conceivable that the alcohol in the exhalation flows into the driver's seat 11 and is adsorbed by the sensor unit 2A. Therefore, the first reference value is set to a relatively high value so that it is determined that the driver is drinking even if there is an inflow of alcohol from the passenger seat 12 side. When -F2) '"is equal to or greater than the first reference value, the control unit 6 determines that the driver is in a drinking state.

  When it is determined that “(F1-F2) ′” is lower than the first reference value, the control unit 6 continues to set “(F1-F2) ′” for the predetermined period. It is determined whether or not the reference value of 2 is maintained (step 2). The second reference value is a numerical value that serves as an index as to whether or not the driver is drinking, but is a value lower than the first reference value. When “(F1-F2) ′” is lower than the second reference value, the control unit 6 determines that the driver is not in a drinking state.

  When the (F1-F2) ′ is kept equal to or higher than the second reference value, the control unit 6 subsequently determines whether (F3-F4) ′ is equal to or higher than the third reference value during the predetermined period. Is determined (step 3). The third reference value is a numerical value that serves as an index as to whether or not the assistant is drinking, for example, the same numerical value as the second reference value. And when the control part 6 determines with (F3-F4) 'being lower than the 3rd reference value, the assistant is not drinking in this case, and (F1-F2) by alcohol in the driver's expiration ) ′ Is considered to be equal to or greater than the second reference value, the control unit 6 determines that the driver is in a drinking state.

  When (F3-F4) 'is equal to or greater than the second reference value, the control unit 6 subsequently determines {(F1-F2)-(F3-F4)}' (step 4). Here, {(F1−F2) − (F3−F4)} ′ is larger than a preset fourth reference value, for example, 0, that is, a decrease in frequency in the sensor unit 2A is compared with a decrease in frequency in the sensor unit 2B. Is higher, the alcohol concentration in the driver's breath is higher than the alcohol concentration in the assistant's breath, and it is determined that the driver is in a drinking state.

  Conversely, {(F1-F2)-(F3-F4)} 'is lower than the third reference value, that is, the decrease in the frequency of the sensor unit 2B is larger than the decrease in the frequency of the sensor unit 2A. In this case, since the alcohol concentration in the breath of the assistant is higher than the alcohol concentration in the breath of the driver, the control section 6 assumes that the breath of the assistant is flowing into the sensor unit 2A, and the controller 6 is not in the drinking state. Is determined.

  When it is determined that the driver is not in a drinking state, the control unit 6 does not interfere with the operation of the engine, and the engine operates according to the operation of the driver. On the other hand, when it is determined that the driver is in a drunk state, the control unit 6 suppresses the movement when the engine is already operating, and gradually, for example, by the speed limiter configuring the engine controller 62. , The operation of the engine is stopped and the travel of the automobile 1 is stopped. In addition, when the engine is stopped, the stopped state is maintained, and even if the driver performs an operation to start the engine by turning the ignition of the car, the operation of the engine is not performed. . In this way, while controlling the operation of the engine, the control unit 6 displays on the display screen 61 that the driver is in a drinking state, and an alarm generation unit 63 generates an alarm in the vehicle.

  The automobile 1 includes a sensor unit 2A including a crystal resonator 3 in which vibration regions 3A and 3B formed from a common crystal piece 31 are formed, and an arithmetic unit 5. The vibration regions 3A and 3B are prevented from generating pulsating flow portions having different sizes with respect to the “F1” and “F2” due to impacts of different strengths and different directions when the vehicle 1 is running or idling. Therefore, it is possible to prevent the pulsating flow portion from remaining in “F1-F2” that is the time series data of the difference value calculated by the calculation unit 5, and the calculation unit 5 further suppresses the pulse remaining in “F1-F2”. The time-series data “(F1-F2) ′” of the difference value is calculated so that the flow portion is removed as noise. Therefore, in this “(F1-F2) ′”, the change due to the alcohol is clear, and the driver's drinking level is determined based on this “(F1-F2) ′”, so with high accuracy. That determination can be made. In particular, it is effective to remove the noise of the time series data when determining drinking by looking at the transition of the time series data of the frequency in a predetermined period.

  In this embodiment, the passenger seat is also provided with the sensor unit 3B, and the difference between the frequency difference between the vibration regions of the sensor unit 2A and the frequency difference between the vibration regions of the sensor unit 2B is calculated. The driver's orientation can be increased, that is, the driver who is not drinking due to the assistant's drinking is prevented from being misidentified as drinking, and the driver's drinking is more accurate The state can be determined. The sensor unit 2B may be provided in the rear seat and may detect the alcohol in the breath of the person sitting on the rear seat, thereby preventing the erroneous determination due to the person's drinking.

  The correspondence between the frequency fluctuations in each of “(F1-F2) ′” and “(F3-F4) ′” and the alcohol concentration in the breath of the driver and the assistant is examined in advance, and “ The alcohol concentration in the breath of the driver and the assistant may be displayed on the display unit 61 in real time according to the change of (F1-F2) ′ ”and“ (F3-F4) ′ ”. .

  In the above embodiment, the moving average is calculated for the difference data “F1-F2” and “F3-F4” of the time-series data obtained from each vibration region, and “(F1-F2) ′” “(F3- F4) ′ ”is acquired and the drinking state is determined based on these data. Instead of removing noise from the difference data of the time series data obtained from each vibration region in this way, the vibration region The determination may be made by removing the noise of the time-series data obtained from the above, and then calculating the difference of the time-series data from which the noise has been removed. Specifically, “F1”, “F2 ′”, “F1 ′”, “F2”, “F1 ′”, “F2”, “F3”, and “F4” are obtained by taking a moving average of the time series data. ”,“ F3 ′ ”,“ F4 ′ ”are calculated and stored in the second memory 56, and the calculation unit 5 further calculates“ F1′−F2 ′ ”,“ F3′−F4 ′ ”,“ (F1 ′ -F2 ')-(F3'-F4') "is calculated and the calculation result is stored in the third memory 57. And the control part 6 is "F1'-F2 '", "F3'-F4 instead of (F1-F2)', (F3-F4) ', {(F1-F2)-(F3-F4)}'. Based on each time-series data of “′” “(F1′−F2 ′) − (F3′−F4 ′)”, the determination is performed in the same manner as in the above embodiment. Even if it is such a structure, the effect similar to the said embodiment is acquired.

  Next, FIG. 10 shows a configuration example of another alcohol detection device. Parts that are formed in the same manner as in the above embodiment are given the same reference numerals. In this embodiment, a mixing circuit 71 is provided downstream of the oscillation circuits 41A and 41B, and a mixing circuit 72 is provided downstream of the oscillation circuits 41C and 41D. The mixing circuit 71 calculates the signal data of the frequency difference based on the signals input from the oscillation circuits 41A and 41B. Similarly, the mixing circuit 72 operates based on the signals input from the oscillation circuits 41C and 41D. The signal data of the frequency difference is calculated, and each calculated data is transmitted to the subsequent stage in the processing unit 4 and stored in the memory. That is, in this example, “F1-F2” and “F3-F4” are calculated before being transmitted to the calculation unit 5. After “F1-F2” and “F3-F4” are calculated in this way, the calculation unit 5 performs “{(F1-F2)-(F3-F4)} based on these as in the above embodiment. ”Is calculated, the moving average of the time-series data of these difference values is calculated, and the time-series data from which noise is removed is output. Even with this configuration, it is possible to obtain the same effects as those of the apparatus having the above configuration.

Evaluation Test According to the above embodiment, time series data of the frequencies “F1”, “F2”, and “F1-F2” are measured, and the results are shown in FIG. In the graph in the figure, the vertical axis indicates the frequencies of F1 and F2, and the horizontal axis indicates time. The frequency “F2” is changed according to the change of “F2” due to the adsorption of alcohol to the vibration region 3B in the vicinity of 3501 seconds at the time “F2”. Therefore, as described in the embodiment, the driver's drinking can be detected using such a frequency change. In the graph, “F1-F2” is shown in one graph in order to clearly show the changes with respect to F1 and F2, and therefore the calculated value at each time point does not correspond to the frequency value on the vertical axis of the graph. However, the amount of change corresponds to the scale interval on the vertical axis.

It is an external view of the motor vehicle carrying the alcohol detection apparatus of this invention. It is a block diagram of the sensor part which comprises the said alcohol detection apparatus. It is the top view and longitudinal cross-sectional side view of the crystal oscillator integrated in the said sensor part. It is a vertical side view of the adsorption layer and non-adsorption layer provided in the crystal unit. It is a block diagram of the said alcohol detection apparatus. It is an example of the time series data of the frequency output. It is an example of the time series data of the frequency output. It is an example of the time series data of the frequency output. It is a flowchart for judging whether a driver is in a drinking state. It is a block diagram of another alcohol detection apparatus. It is the graph which showed the result of the evaluation test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car 2A, 2B Sensor part 3 Crystal oscillator 3A, 3B, 3C, 3D Vibration area 4 Processing part 41A, 41B, 41C, 41D Oscillation circuit 5 Calculation part 53 Data processing program 54 Noise removal program 6 Control part 61 Display part 62 Engine controller

Claims (6)

In an alcohol detection device for detecting alcohol included in a breath of a driver of a vehicle provided in a vehicle,
An adsorption layer for adsorbing the alcohol is formed on the surface, and a vibration region for alcohol detection in which the natural frequency changes due to the adsorption of alcohol to the adsorption layer is different from the vibration region for detection. A first crystal resonator provided with a reference vibration region that is provided and does not adsorb the alcohol;
Oscillation means for independently oscillating the vibration region for detection and the vibration region for reference of the first crystal unit;
The difference between these frequencies based on the frequency corresponding to the oscillation output of the vibration region for detection in the first crystal resonator and the frequency corresponding to the oscillation output of the reference vibration region in the first crystal resonator. Data creation means for verification including means for creating time-series data of values, and means for removing the pulsating flow portion included in the time-series data as noise.
An alcohol detection device comprising:   The verification data creation means includes means for creating time series data of a frequency corresponding to the oscillation output of the vibration region for detection instead of the configuration described in claim 1, and the vibration region for reference 2. A means for generating time series data of a frequency corresponding to the oscillation output of the first and second means for removing a pulsating flow portion included in each time series data as noise. The alcohol detection apparatus described. An adsorption layer for adsorbing alcohol contained in exhaled breath of passengers other than the driver is formed on the surface, and a vibration region for alcohol detection in which the natural frequency changes due to adsorption of alcohol to the adsorption layer, and this A second crystal resonator provided with a reference vibration region provided in a region different from the detection vibration region and not adsorbing the alcohol;
Oscillation means for independently oscillating the vibration region for detection and the vibration region for reference of the second crystal unit;
The difference between these frequencies based on the frequency corresponding to the oscillation output of the vibration region for detection in the second crystal resonator and the frequency corresponding to the oscillation output of the reference vibration region in the second crystal resonator. Data generating means for comparison including means for generating time-series data of values, and means for removing the pulsating flow portion included in the time-series data as noise.
Detection means for detecting alcohol based on the comparison data and the verification data;
The alcohol detection device according to claim 1, further comprising:   The comparison data creation means includes means for creating time series data of a frequency corresponding to the oscillation output of the vibration region for detection instead of the configuration described in claim 3, and the vibration region for reference 4. A means for creating time series data of a frequency corresponding to the oscillation output of the above and means for removing a pulsating flow portion included in each time series data as noise. The alcohol detection apparatus described.   The alcohol detection device according to any one of claims 1 to 4, wherein the removal of the pulsating portion is performed by taking a moving average with respect to time-series data. In a vehicle equipped with an alcohol detection device for detecting alcohol contained in a driver's breath,
Based on the detection result of the alcohol detection device according to any one of claims 1 to 5 and the detection means, a control unit for restricting traveling of the vehicle by the operation of the driver,
A vehicle characterized by comprising:

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