Driver state detection device

Abstract

To provide a driver state detection device for improving the detection accuracy of the attention reduction state of a driver.SOLUTION: A driver-state detection device comprising: a concentration measuring unit that measures a gas concentration in a cabin of a vehicle; and a state detection unit that detects a reduced-attention state of a driver when the gas concentration measured by the concentration measuring unit is equal to or higher than a first concentration threshold continuously for a time threshold or longer.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driver condition detection device. [Background technology]

[0002] In recent years, from the viewpoint of safety, there has been a trend for vehicles to be equipped with a driver monitoring system that monitors the driver of the vehicle. Patent Document 1 listed below discloses an example of a driver monitoring system that includes an imaging device and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-202726 Summary of the Invention [Problem to be solved by the invention]

[0004] Such a driver monitoring system detects a driver's decreased attention and sounds an alert to the driver by using information derived from the driver, such as information obtained by capturing an image of the driver's face and its surroundings with an imaging device.

[0005] However, when detecting a driver's state of impaired attention using information derived from the driver, for example, if the detection accuracy of the driver monitoring system is set too strict, there is a possibility that the detection of the driver's state of impaired attention may be inconsistent. In other words, in such a case, an alert may be issued even when the driver is not in a state of impaired attention (for example, an alert may sound unnecessarily).

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a driver condition detection device that improves the accuracy of detecting a driver's state of decreased attention. [Means for solving the problem]

[0007] The present invention has been made to solve at least some of the above-mentioned problems, and can be realized as the following aspects or application examples.

[0008] (1) The driver condition detection device according to this application example includes a concentration measurement unit that measures the gas concentration in the vehicle cabin, and a condition detection unit that detects the driver's state of decreased attention when the concentration measurement unit measures a gas concentration equal to or greater than a first concentration threshold for a period of time equal to or greater than a time threshold.

[0009] In this application example, information on the gas concentration in the vehicle cabin is used to detect the driver's state of reduced attention. Since the information on the gas concentration in the vehicle cabin is information derived from the vehicle's interior environment, this application example can reduce fluctuations in the detection accuracy of the driver's state of reduced attention even if the driver changes. Therefore, according to this application example, it is possible to improve the detection accuracy of the driver's state of reduced attention.

[0010] (2) The driver state detection device according to this application example includes a concentration measurement unit that measures the gas concentration inside the vehicle cabin, a driver monitoring unit that monitors the driver of the vehicle, a state estimation unit that estimates the state of the driver based on information acquired by the driver monitoring unit, and a state detection unit that detects the driver's state of reduced attention when the concentration measurement unit measures a gas concentration equal to or greater than a first concentration threshold for a period equal to or greater than a time threshold and the state estimation unit estimates that the driver's state is in a state of reduced attention.

[0011] In this application example, information on gas concentration in the vehicle cabin and information acquired by the driver monitoring unit are used to detect the driver's state of diminished attention. The information on gas concentration in the vehicle cabin is information derived from the vehicle's interior environment, and the information acquired by the driver monitoring unit is information derived from the driver. Furthermore, each of the information on gas concentration in the vehicle cabin and the information acquired by the driver monitoring unit can be used as an independent element for detecting the driver's state of diminished attention. In other words, in this application example, whether the driver is in a state of diminished attention is determined from two perspectives. Therefore, in this application example, fluctuations in the detection accuracy of the driver's state of diminished attention can be reduced compared to when the driver's state of diminished attention is detected using only one of the information on gas concentration in the vehicle cabin and the information acquired by the driver monitoring unit. Therefore, according to this application example, the detection accuracy of the driver's state of diminished attention can be further improved.

[0012] (3) A driver state detection device according to the application example of (1) or (2) above includes a notification unit that issues an alert, and a notification processing unit that issues an alert to the driver by the notification unit when the state detection unit detects that the driver's attention is reduced.

[0013] According to the above configuration, an alert can be issued to the driver in response to the state of decreased attention of the driver being detected by the state detection unit.

[0014] (4) A driver condition detection device relating to the application example of (1) or (2) above further includes an air conditioning unit that can switch between a circulation mode that circulates air inside the vehicle cabin and an intake mode that takes in air outside the vehicle cabin into the vehicle cabin, and a condition setting unit that sets the operating conditions of the air conditioning unit, and the condition setting unit switches the air conditioning unit from the circulation mode to the intake mode when the concentration measuring unit measures a gas concentration that is equal to or greater than a second concentration threshold, which is a concentration threshold that is equal to or greater than the first concentration threshold, or when the concentration measuring unit measures a gas concentration that is equal to or greater than the first concentration threshold for a period of time that is equal to or greater than the time threshold.

[0015] According to the above configuration, when the environment inside the vehicle is such that the driver's attention is reduced, the rate of increase in the carbon dioxide concentration inside the vehicle is reduced, the increase in the carbon dioxide concentration inside the vehicle is suppressed, or the carbon dioxide concentration inside the vehicle is reduced.

[0016] (5) In the driver condition detection device relating to the application example of (4) above, the air conditioning unit is capable of switching between a low air volume mode and a high air volume mode in which the volume of air drawn into the vehicle cabin is greater than that in the low air volume mode, and the condition setting unit switches the air conditioning unit from the low air volume mode to the high air volume mode when the concentration measurement unit measures a carbon dioxide concentration equal to or greater than a third concentration threshold, which is a concentration threshold equal to or greater than the second concentration threshold, or when the concentration measurement unit measures a gas concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the time threshold.

[0017] According to the above configuration, when the environment inside the vehicle is such that the driver's attention is reduced, the rate of increase of the carbon dioxide concentration inside the vehicle is further reduced, the increase in the carbon dioxide concentration inside the vehicle is suppressed, or the carbon dioxide concentration inside the vehicle is further reduced.

[0018] (6) In the driver's condition detection device according to the application example of (1) or (2) above, the larger the first concentration threshold value, the shorter the time threshold value is set.

[0019] According to the above configuration, the time threshold can be set in accordance with the first concentration threshold, and for example, it is possible to detect a state of decreased attention of the driver before the driver becomes excessively decreased in attention.

[0020] (7) The driver status detection device according to the application example (1) or (2) above further includes an occupant detection unit that detects each of the occupants of the vehicle, and the greater the number of occupants of the vehicle, the shorter the time threshold is set.

[0021] According to the above configuration, the time threshold can be set according to the number of occupants in the vehicle, and for example, a state of decreased attention of the driver can be detected before the driver becomes excessively decreased in attention.

[0022] (8) In the driver state detection device according to the application example of (1) or (2) above, when the vehicle is parked, the time threshold is set shorter than when the vehicle is moving.

[0023] According to the above configuration, the time threshold can be set in accordance with the state of the vehicle, and for example, a state of decreased attention of the driver can be detected before the driver becomes excessively decreased in attention. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing the configuration of a vehicle according to a first embodiment. [Figure 2] 1 is a block diagram showing an electrical configuration of a driver condition detection device according to a first embodiment. [Figure 3] 3 is a flowchart showing an example of the operation of a control unit of the driver condition detection device of the first embodiment. FIG. [Figure 4] 3 is a flowchart showing an example of the operation of a control unit of the driver condition detection device of the first embodiment. FIG. [Figure 5] 3 is a flowchart showing an example of the operation of a control unit of the driver condition detection device of the first embodiment. FIG. [Figure 6] FIG. 10 is a schematic diagram showing the configuration of a vehicle according to a second embodiment. [Figure 7] FIG. 5 is a block diagram showing the electrical configuration of a driver condition detection device according to a second embodiment. [Figure 8] 10 is a flowchart showing an example of the operation of a control unit of a driver condition detection device according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] 1. Configuration of the vehicle of the first embodiment 1 is a schematic diagram showing the configuration of a vehicle 1 according to a first embodiment. Specifically, the vehicle 1 is an automobile. The vehicle 1 includes a first inlet 12, a first outlet 14, a second inlet 16, a second outlet 18, an air conditioning unit 20, a notification unit 22, and a concentration measurement unit 28.

[0026] The first inlet 12 is provided outside the vehicle 1 and is an opening for introducing air outside the vehicle 1 into the air conditioning unit 20. The first inlet 12 is connected to the air conditioning unit 20 via a duct. In FIG. 1, each duct is indicated by a dashed line.

[0027] The first outlet 14 is an opening provided in the interior of the vehicle 1 for discharging air whose temperature has been adjusted by the air conditioning unit 20 into the interior of the vehicle 1. The first outlet 14 is connected to the air conditioning unit 20 via a duct.

[0028] The second inlet 16 is provided in the interior of the vehicle 1 at a position lower than the first outlet 14, and is an opening for introducing air from the interior of the vehicle 1 into the air conditioning unit 20. The second inlet 16 is connected to the air conditioning unit 20 via a duct.

[0029] The second outlet 18 is an opening provided in the vehicle 1 for discharging the air inside the vehicle 1 to the outside of the vehicle 1. The second outlet 18 can also be said to be a communication port that connects the inside of the vehicle 1 with the outside.

[0030] The air conditioning unit 20 is an HVAC (Heating, Ventilation and Air Conditioning) unit that adjusts the temperature of the air introduced through the first inlet 12 or the second inlet 16 and supplies that air to the interior of the vehicle 1, and is mounted inside the hood of the vehicle 1.

[0031] The air conditioning unit 20 includes a compressor, a condenser, a receiver, an expansion valve, an evaporator, a refrigerant circuit (heat medium circuit), a heater, a switching valve, a blower, and an air volume adjustment damper.

[0032] The switching valve of the air conditioning unit 20 switches whether to take in air from the first inlet 12 or the second inlet 16. Therefore, the air conditioning unit 20 can switch between a circulation mode in which the air inside the vehicle 1 is circulated, and an intake mode in which the air outside the vehicle 1 is taken into the vehicle 1.

[0033] The blower, air volume adjustment damper, etc. of the air conditioning unit 20 adjust the volume of air discharged from the first outlet 14 into the interior of the vehicle 1. Therefore, the air conditioning unit 20 can switch between a low air volume mode in which the volume of air discharged into the interior of the vehicle 1 is smaller than in the high air volume mode, and a high air volume mode in which the volume of air discharged into the interior of the vehicle 1 is larger than in the low air volume mode.

[0034] The notification unit 22 is provided in the interior of the vehicle 1 and issues an alert as appropriate. Specifically, the notification unit 22 includes a display unit 24 for displaying an alert message and a sound unit 26 for sounding an alert message, and issues the alert visually and audibly. The notification unit 22 is, for example, a car navigation terminal.

[0035] The concentration measurement unit 28 is a carbon dioxide concentration meter provided in the interior of the vehicle 1. The concentration measurement unit 28 measures the carbon dioxide concentration in the interior of the vehicle 1. The measurement result by the concentration measurement unit 28 is displayed on the display unit 24 so that it can be seen.

[0036] Carbon dioxide concentrations are divided into several stages based on concentration thresholds, such as stage 1 (less than 1000 ppm), stage 2 (1000 ppm to less than 2500 ppm), stage 3 (2500 ppm to less than 5000 ppm), and stage 4 (5000 ppm or more).

[0037] Display unit 24 visually displays the concentration level to which the measurement result belongs along with the measurement result from concentration measurement unit 28. For example, display unit 24 displays the measurement result from concentration measurement unit 28 in different colors according to the concentration level.

[0038] 2. Configuration of the driver condition detection device of the first embodiment 2 is a block diagram showing the electrical configuration of the driver condition detection device 40 of the first embodiment. The vehicle 1 further includes the driver condition detection device 40. When the driver condition detection device 40 detects a state of decreased attention of the driver P1 (such as a state of drowsiness or a state of decreased consciousness), it issues an alert to the driver P1.

[0039] It should be noted that the higher the carbon dioxide concentration in the cabin of the vehicle 1, the more it affects the driver P1's attention decline. Therefore, when detecting the driver P1's state of decreased attention, the measurement result by the concentration measurement unit 28 is used.

[0040] The driver's condition detection device 40 includes a control unit 50 in addition to the air conditioning unit 20, the notification unit 22, the concentration measurement unit 28, and the like.

[0041] The control unit 50 is a computer that performs overall control of the vehicle 1, and also performs overall control of the driver condition detection device 40. The control unit 50 is, for example, an ECU (Electronic Control Unit).

[0042] The control unit 50 includes a CPU (Central Processing Unit) 60, a storage unit 80 that can be directly accessed by the CPU 60, etc. The storage unit 80 is, for example, a hard disk drive (HDD), a read only memory (ROM), a random access memory (RAM), a solid state drive (SSD), or any combination thereof.

[0043] The storage unit 80 stores programs and data for controlling the operation of the various components of the driver condition detection device 40. Furthermore, data acquired by the various components of the driver condition detection device 40 is appropriately stored in the storage unit 80. Note that the data acquired by the various components of the driver condition detection device 40 may be stored in the storage unit 80 so as to be updated, or multiple pieces of data may be stored in the storage unit 80.

[0044] As described above, the concentration measurement unit 28 measures the carbon dioxide concentration in the cabin of the vehicle 1. Therefore, the concentration measurement unit 28 causes the memory unit 80 to store measured concentration data 82 indicating the measurement result of the carbon dioxide concentration in the cabin of the vehicle 1.

[0045] The storage unit 80 also stores in advance first concentration threshold data 84, second concentration threshold data 86, and third concentration threshold data 88. The first concentration threshold data 84 is data indicating a first concentration threshold for carbon dioxide concentration. The second threshold data 76 is data indicating a second concentration threshold for carbon dioxide concentration. The third threshold data 78 is data indicating a third concentration threshold for carbon dioxide concentration.

[0046] The first concentration threshold is an arbitrary value. The second concentration threshold is an arbitrary value equal to or greater than the first concentration threshold. The third concentration threshold is an arbitrary value equal to or greater than the second concentration threshold. In the first embodiment, the first concentration threshold is set to 1000 ppm, the second concentration threshold is set to 2500 ppm, and the third concentration threshold is set to 5000 ppm.

[0047] Furthermore, the storage unit 80 stores time threshold data 92 in advance. The time threshold data 92 is data indicating a time threshold for measurement time. The time threshold is an arbitrary time. In the first embodiment, the time threshold is set to one hour.

[0048] Furthermore, notification data 94 is pre-stored in the storage unit 80. The notification data 94 is data for notifying the driver P1 of an alert, and corresponds to the configuration of the notification unit 22. The notification data 94 may include images, videos, or text data to be displayed on the display unit 24. The notification data 94 may also include audio data to be produced by the audio output unit 26.

[0049] As described above, the memory unit 80 stores programs and data for controlling the operation of various components of the driver condition detection device 40, and the CPU 60 executes the programs to function as a concentration display unit 62, a time measurement unit 64, a condition detection unit 66, an alarm processing unit 68, a condition setting unit 70, and the like.

[0050] The concentration display unit 62 refers to the measured concentration data 82 and visibly displays the measurement results by the concentration measurement unit 28 on the display unit 24. Furthermore, the concentration measurement unit 28 also refers to first concentration threshold data 84, second concentration threshold data 86, third concentration threshold data 88, etc. in addition to the measured concentration data 82, and visibly displays on the display unit 24 to which concentration stage the measurement results by the concentration measurement unit 28 belong.

[0051] The time measurement unit 64 refers to the measured concentration data 82 and the first concentration threshold data 84, and starts measuring time when a carbon dioxide concentration equal to or greater than the first concentration threshold is measured by the concentration measurement unit 28. The time measurement unit 64 also refers to the measured concentration data 82 and the first concentration threshold data 84, and stops measuring time when a carbon dioxide concentration less than the first concentration threshold is measured by the concentration measurement unit 28. The time measured by the time measurement unit 64 is stored in the memory unit 80 as measured time data 90.

[0052] The state detection unit 66 refers to the measurement time data 90 and the time threshold data 92, and when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the time threshold, it detects (determines) that the driver P1 is in a state of decreased attention.

[0053] When the state detection unit 66 detects that the driver P1 is in a state of decreased attention, the notification processing unit 68 uses the notification data 94 to cause the notification unit 22 to issue an alert to the driver P1.

[0054] The content of the alert to the driver P1 notified by the notification unit 22 by the notification processing unit 68 may be to make the driver P1 aware of a decline in attention, to encourage the driver P1 to take a rest, to make the driver P1 aware of a method for reducing the carbon dioxide concentration in the cabin of the vehicle 1, to encourage the driver P1 to carry out that method, or may include two or more of these.

[0055] The condition setting unit 70 sets the operating conditions of the air conditioning unit 20. The condition setting unit 70 refers to the measured concentration data 82 and the second concentration threshold data 86, and when the carbon dioxide concentration measured by the concentration measurement unit 28 is equal to or greater than the second concentration threshold, switches the air conditioning unit 20 from the circulation mode to the intake mode.

[0056] In addition, the condition setting unit 70 refers to the measured concentration data 82 and the third concentration threshold data 88, and when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the third concentration threshold, switches the air conditioning unit 20 from low airflow mode to high airflow mode.

[0057] 3. Example of Operation of Driver Condition Detection Device of First Embodiment 3 to 5 are flow charts showing an example of the operation of the control unit 50 of the driver condition detection device 40 of the first embodiment. The flow shown in Fig. 3 is started, for example, when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or higher than the first concentration threshold.

[0058] In step S1, the time measurement unit 64 of the control unit 50 starts measuring time, and the control unit 50 proceeds to step S2.

[0059] In step S2, the control unit 50 determines whether the carbon dioxide concentration is equal to or greater than the first concentration threshold. If step S2 returns "NO," that is, if the carbon dioxide concentration is less than the first concentration threshold, the control unit 50 proceeds to step S6. On the other hand, if step S2 returns "YES," that is, if the carbon dioxide concentration is equal to or greater than the first concentration threshold, the control unit 50 proceeds to step S3.

[0060] In step S3, the control unit 50 determines whether the measured time is equal to or greater than the time threshold. If the result of step S3 is "NO," that is, if the measured time is less than the time threshold, the control unit 50 returns the process to step S2. On the other hand, if the result of step S3 is "YES," that is, if the measured time is equal to or greater than the time threshold, the control unit 50 proceeds to step S4.

[0061] In step S4, the state detection unit 66 of the control unit 50 detects that the driver P1 is in a state of decreased attention, and the control unit 50 proceeds to the process of step S5.

[0062] In step S5, the notification processing unit 68 of the control unit 50 causes the notification unit 22 to issue an alert to the driver P1, and the control unit 50 proceeds to step S6.

[0063] In step S6, the time measurement unit 64 of the control unit 50 ends the time measurement, and the control unit 50 ends the flow.

[0064] The flow shown in FIG. 4 starts, for example, when the concentration measurement unit 28 measures a carbon dioxide concentration that is equal to or greater than the second concentration threshold, which is equal to or greater than the first concentration threshold.

[0065] In step S7, the control unit 50 determines whether the air conditioning unit 20 is in the circulation mode. If the determination in step S7 is "NO," that is, if the air conditioning unit 20 is in the intake mode, the control unit 50 ends the flow. On the other hand, if the determination in step S7 is "YES," that is, if the air conditioning unit 20 is in the circulation mode, the control unit 50 proceeds to step S8.

[0066] In step S8, the condition setting unit 70 of the control unit 50 switches the air conditioning unit 20 from the circulation mode to the intake mode, and the control unit 50 ends the flow.

[0067] The flow shown in FIG. 5 starts, for example, when the concentration measurement unit 28 measures a carbon dioxide concentration that is equal to or greater than the third concentration threshold, which is a value equal to or greater than the second concentration threshold.

[0068] In step S9, the control unit 50 determines whether the air conditioning unit 20 is in the low airflow mode. If the determination in step S9 is "NO," that is, if the air conditioning unit 20 is in the high airflow mode, the control unit 50 ends the flow. On the other hand, if the determination in step S9 is "YES," that is, if the air conditioning unit 20 is in the low airflow mode, the control unit 50 proceeds to step S10.

[0069] In step S10, the condition setting unit 70 of the control unit 50 switches the air conditioning unit 20 from the low air volume mode to the high air volume mode, and the control unit 50 ends the flow.

[0070] In the driver condition detection device 40 of the first embodiment, information on the carbon dioxide concentration in the cabin of the vehicle 1 is used to detect the driver P1's state of diminished attention. Since the information on the carbon dioxide concentration in the cabin of the vehicle 1 is information derived from the cabin environment of the vehicle 1, the driver condition detection device 40 of the first embodiment can reduce fluctuations in the detection accuracy of the driver P1's state of diminished attention, even if the driver P1 changes. Therefore, the driver condition detection device 40 of the first embodiment can reduce fluctuations in the detection accuracy of the driver P1's state of diminished attention, in other words, can improve the detection accuracy of the driver P1's state of diminished attention, and can issue an alert to the driver P1 at an appropriate time.

[0071] Furthermore, in the driver state detection device 40 of the first embodiment, if a carbon dioxide concentration equal to or greater than the first concentration threshold continues for a time threshold or longer, measured by the concentration measurement unit 28, the driver P1 is detected as being in a state of decreased attention. Therefore, even if the carbon dioxide concentration has a weak effect on the driver P1's decreased attention, that is, if the carbon dioxide concentration is not such that the driver P1 immediately enters a state of decreased attention (for example, equal to or greater than the first concentration threshold and less than the second concentration threshold), the driver P1 can be detected as being in a state of decreased attention if the concentration continues for a time threshold or longer.

[0072] Furthermore, regardless of whether a carbon dioxide concentration equal to or greater than the first concentration threshold has been measured continuously for equal to or greater than the time threshold, when a carbon dioxide concentration equal to or greater than the second concentration threshold is measured by the concentration measurement unit 28, the condition setting unit 70 switches the air conditioning unit 20 from the circulation mode to the intake mode. Therefore, according to the driver state detection device 40 of the first embodiment, when the environment inside the vehicle 1 is one that tends to decrease the attention of the driver P1, the rate of increase in the carbon dioxide concentration inside the vehicle 1 is reduced, the increase in the carbon dioxide concentration inside the vehicle 1 is suppressed, or the carbon dioxide concentration inside the vehicle 1 is reduced.

[0073] Furthermore, in the driver state detection device 40 of the first embodiment, when a carbon dioxide concentration equal to or greater than the third concentration threshold is measured by the concentration measurement unit 28, the condition setting unit 70 switches the air conditioning unit 20 from the circulation mode to the intake mode, and also switches the air conditioning unit 20 from the low airflow mode to the high airflow mode, regardless of whether a carbon dioxide concentration equal to or greater than the first concentration threshold has been continuously measured for more than the time threshold. Therefore, the driver state detection device 40 of the first embodiment can further reduce the rate of increase of the carbon dioxide concentration in the cabin of the vehicle 1, suppress the increase in the carbon dioxide concentration in the cabin of the vehicle 1, or further reduce the carbon dioxide concentration in the cabin of the vehicle 1.

[0074] 4. Configuration of vehicle according to second embodiment 6 is a schematic diagram showing the configuration of a vehicle 1 according to the second embodiment. A driver condition detection device 40 and the like according to the second embodiment will be described below, but descriptions that overlap with those of the first embodiment may be omitted.

[0075] The vehicle 1 of the second embodiment further includes a driver monitoring unit 30. The driver monitoring unit 30 includes a face monitoring unit 32 and a behavior monitoring unit 34, and monitors the driver P1.

[0076] The face monitoring unit 32 is a general-purpose imaging device provided in the interior of the vehicle 1, and monitors the area around the face of the driver P1 by capturing an image of the area around the face of the driver P1. In other words, the face monitoring unit 32 directly monitors the driver P1.

[0077] The behavior monitoring unit 34 includes one or more general-purpose sensors that sense the behavior of the vehicle 1, and monitors the driving operation of the driver P1 that is reflected in the behavior of the vehicle 1 by monitoring the behavior of the vehicle 1. In other words, the behavior monitoring unit 34 indirectly monitors the driver P1. The behavior monitoring unit 34 includes, for example, a GPS sensor, an acceleration sensor, a gyro sensor, and an ultrasonic sensor.

[0078] 5. Configuration of the driver condition detection device of the second embodiment 7 is a block diagram showing the electrical configuration of the driver condition detection device 40 of the second embodiment. The driver condition detection device 40 of the second embodiment further includes the above-mentioned driver monitoring unit 30. In addition, the storage unit 80 appropriately stores monitoring data 96 indicating information acquired by the driver monitoring unit 30.

[0079] The monitoring data 96 includes face monitoring data 98 ​​indicating information acquired by the face monitoring unit 32, and behavior monitoring data 100 indicating information acquired by the behavior monitoring unit .

[0080] The face monitoring data 98 ​​is specifically image data or video data. The behavior monitoring data 100 is specifically data output from various sensors that sense the behavior of the vehicle 1.

[0081] In the second embodiment, the CPU 60 executes a program to function as a state estimation unit 72. The state estimation unit 72 estimates the state of the driver P1 based on information acquired by the driver monitoring unit 30, i.e., the monitoring data 96. In other words, the state estimation unit 72 estimates the state of the driver P1 based on information derived from the driver P1.

[0082] Regarding the state estimation unit 72, a method for estimating the driver P1's attentiveness state based on information acquired by the driver monitoring unit 30 may be, for example, a combination of one or more of the following: the face monitoring unit 32 detecting that the driver P1's eye opening rate is below a predetermined value for a predetermined period of time or more; the driver P1's face being directed away from the front for a predetermined period of time or more; or the driver P1 yawning a predetermined number of times or more within a predetermined period of time. Other methods may also be used.

[0083] Regarding the state estimation unit 72, a possible method for estimating the driver P1's state of decreased attention based on information acquired by the driver monitoring unit 30 is to combine one or more of the following: the occurrence of a behavior of the vehicle 1 such as repeated meandering a predetermined number of times or more within a predetermined time period detected by each sensor of the behavior monitoring unit 34; or the occurrence of a behavior of the vehicle 1 due to sudden acceleration or sudden deceleration. Other methods may also be used.

[0084] The state detection unit 66 of the second embodiment detects that the driver P1 is in a state of reduced attention when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the time threshold, and the state estimation unit 72 estimates that the driver P1 is in a state of reduced attention.

[0085] 6. Example of operation of the driver condition detection device of the second embodiment 8 is a flow chart showing an example of the operation of the control unit 50 of the driver condition detection device 40 of the second embodiment. Note that, since the example of the operation of the control unit 50 of the driver condition detection device 40 of the second embodiment is the same as that of the first embodiment, the explanation of steps S1 to S3 and steps S5 to S6 will be omitted.

[0086] In the second embodiment, if the answer is "YES" in step S3, the control unit 50 proceeds to step S11. In step S11, the control unit 50 determines whether the driver P1 is estimated to be in a state of reduced attention. If the answer is "NO" in step S11, that is, if the driver P1 is not estimated to be in a state of reduced attention, the control unit 50 returns the process to step S2. On the other hand, if the answer is "YES" in step S11, that is, if the driver P1 is estimated to be in a state of reduced attention, the control unit 50 proceeds to step S4.

[0087] In the driver condition detection device 40 of the second embodiment, information on the carbon dioxide concentration in the cabin of the vehicle 1 and information acquired by the driver monitoring unit 30 are used to detect the driver P1's state of diminished attention. The information on the carbon dioxide concentration in the cabin of the vehicle 1 is information derived from the cabin environment of the vehicle 1, and the information acquired by the driver monitoring unit 30 is information derived from the driver P1. Furthermore, the information on the carbon dioxide concentration in the cabin of the vehicle 1 and the information acquired by the driver monitoring unit 30 can be used as independent elements for detecting the driver P1's state of diminished attention. In other words, the driver condition detection device 40 of the second embodiment determines whether the driver P1 is in a state of diminished attention from two perspectives. Therefore, the driver condition detection device 40 of the second embodiment can further reduce fluctuations in the detection accuracy of the driver P1's state of diminished attention compared to when the driver P1's state of diminished attention is detected using only one of the information on the carbon dioxide concentration in the cabin of the vehicle 1 and the information acquired by the driver monitoring unit 30. Therefore, according to the driver condition detection device 40 of the second embodiment, fluctuations in the detection accuracy of the driver P1's state of decreased attention can be further suppressed, in other words, the detection accuracy of the driver P1's state of decreased attention can be further improved, and an alert can be issued to the driver P1 at a more appropriate timing.

[0088] This concludes the description of each embodiment of the present invention, but the specific configurations shown in each embodiment are merely examples, and the aspects of the present invention are not limited to the configurations shown in these embodiments.

[0089] In each embodiment, assuming a measurement error or erroneous measurement by the concentration measurement unit 28, if the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the second concentration threshold and the carbon dioxide concentration remains equal to or greater than the second concentration threshold for a predetermined time (e.g., 10 seconds, 1 minute, etc.) after the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the second concentration threshold, the air conditioning unit 20 may be switched from the circulation mode to the intake mode. Also, if the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the third concentration threshold and the carbon dioxide concentration remains equal to or greater than the third concentration threshold for a predetermined time (e.g., 10 seconds, 1 minute, etc.) after the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the third concentration threshold, the air conditioning unit 20 may be switched from the low airflow mode to the high airflow mode.

[0090] In each embodiment, the second concentration threshold is any value greater than or equal to the first concentration threshold, and the third concentration threshold is any value greater than or equal to the second concentration threshold, but the second concentration threshold may be any value greater than the first concentration threshold, and the third concentration threshold may be any value greater than the second concentration threshold.

[0091] In addition, in each embodiment, it is preferable that the first concentration threshold is 1000 ppm, the second concentration threshold is 2500 ppm, the third concentration threshold is 5000 ppm, and the time threshold is 1 hour, but these may be changed as appropriate. Note that the higher the carbon dioxide concentration in the vehicle 1, the stronger the effect of carbon dioxide on the driver P1's attentiveness. Therefore, in the driver condition detection device 40, the higher the first concentration threshold, the shorter the time threshold. In other words, in the driver condition detection device 40, the first concentration threshold and the time threshold have a trade-off relationship. This allows the time threshold to be set corresponding to the first concentration threshold. For example, it is possible to detect the driver P1's attentiveness state, issue an alert, and switch the operating conditions of the air conditioning unit 20 before the driver P1's attentiveness becomes excessively impaired.

[0092] Furthermore, the greater the number of occupants P in the vehicle 1, the higher the rate of increase in the carbon dioxide concentration inside the vehicle 1. Therefore, in the driver condition detection device 40, it is preferable to shorten the time threshold as the number of occupants P increases. In other words, it is preferable for the driver condition detection device 40 to have a trade-off relationship between the number of occupants P and the time threshold. This makes it possible to set the time threshold according to the number of occupants P in the vehicle 1, and, for example, to detect the driver P1's state of reduced attention, issue an alert, switch the operating conditions of the air conditioning unit 20, and so on, before the driver P1 becomes excessively reduced in attention.

[0093] Furthermore, when the vehicle 1 is parked, the vehicle 1 is not exposed to wind while the vehicle 1 is traveling. Therefore, when the vehicle 1 is parked, the rate of increase in the carbon dioxide concentration inside the vehicle 1 is higher than when the vehicle 1 is traveling. Therefore, in the driver state detection device 40, it is preferable to shorten the time threshold when the vehicle 1 is parked compared to when the vehicle 1 is traveling. This allows the time threshold to be set according to the state of the vehicle 1, and, for example, it is possible to detect the driver P1's state of reduced attention, issue an alert, and switch the operating conditions of the air conditioning unit 20 before the driver P1 becomes excessively reduced in attention.

[0094] If it is expected that the carbon dioxide concentration will increase slowly, the condition setting unit 70 in each embodiment may switch the air conditioning unit 20 from the circulation mode to the intake mode when the concentration measuring unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold for a period equal to or greater than the time threshold, and then the concentration measuring unit 28 measures a carbon dioxide concentration equal to or greater than the second concentration threshold.

[0095] Furthermore, if it is expected that the carbon dioxide concentration will increase slowly, the condition setting unit 70 in each embodiment may switch the air conditioning unit 20 from the low airflow mode to the high airflow mode when the concentration measuring unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the time threshold, and then the concentration measuring unit 28 measures a carbon dioxide concentration equal to or greater than the third concentration threshold.

[0096] The condition setting unit 70 in each embodiment may switch the air conditioning unit 20 from the circulation mode to the intake mode when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or longer. Furthermore, the condition setting unit 70 in each embodiment may switch the air conditioning unit 20 from the low airflow mode to the high airflow mode when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or longer. Note that, in this way, when the operating conditions of the air conditioning unit 20 are changed because the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or longer, the notification unit 22 may issue an alert that the operating conditions of the air conditioning unit 20 will be changed.

[0097] The condition setting unit 70 of the second embodiment may switch from the circulation mode to the intake mode when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or more and the state estimation unit 72 estimates that the driver P1 is in a state of reduced attention. Furthermore, the condition setting unit 70 of the second embodiment may switch from the low airflow mode to the high airflow mode when the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or more and the state estimation unit 72 estimates that the driver P1 is in a state of reduced attention. In this way, when the operating conditions of the air conditioning unit 20 are changed because the concentration measurement unit 28 measures a carbon dioxide concentration equal to or greater than the first concentration threshold continuously for a time threshold or more and the state estimation unit 72 estimates that the driver P1 is in a state of reduced attention, the notification unit 22 may issue an alert that the operating conditions of the air conditioning unit 20 will be changed.

[0098] In each embodiment, the concentration measurement unit 28 measures the carbon dioxide concentration in the cabin of the vehicle 1, but as described above, if it is possible to detect a state of decreased attention of the driver P1, the concentration measurement unit 28 may also measure the concentration of other gases in the cabin of the vehicle 1.

[0099] Furthermore, with regard to each embodiment, the flow diagram showing the operation of the driver condition detection device 40 is merely an example, and the order of steps may be changed as long as similar results are obtained. For example, in the second embodiment, after the state estimation unit 72 estimates that the driver P1 is in a state of impaired attention, the driver P1's state of impaired attention may be detected in response to the concentration measurement unit 28 measuring a carbon dioxide concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the threshold. [Explanation of symbols]

[0100] 1 vehicle 20 Air Conditioning Section 22 Information Department 28 Concentration measurement section 30 Driver Monitoring Department 40 Driver status detection device 66 Status detection unit 68 Notification processing section 70 Condition setting section 72 State Estimation Unit

Claims

1. a concentration measuring unit that measures a gas concentration in a vehicle cabin; A driver condition detection device comprising: a condition detection unit that detects a state of decreased attention of the driver when a gas concentration equal to or greater than a first concentration threshold is measured by the concentration measurement unit for a period equal to or greater than a time threshold.

2. a concentration measuring unit that measures a gas concentration in a vehicle cabin; a driver monitoring unit that monitors the driver of the vehicle; a state estimation unit that estimates a state of the driver based on information acquired by the driver monitoring unit; A driver state detection device comprising a state detection unit that detects the driver's state of reduced attention when the concentration measurement unit measures a gas concentration equal to or greater than a first concentration threshold for a period of time equal to or greater than a time threshold and the state estimation unit estimates that the driver's state is a state of reduced attention.

3. a notification unit that issues an alert; The driver's state detection device according to claim 1 , further comprising: a notification processing unit that, when the state detection unit detects that the driver's attention has decreased, issues an alert to the driver using the notification unit.

4. an air conditioning unit that can switch between a circulation mode that circulates air inside the vehicle and an intake mode that takes in air outside the vehicle into the vehicle; A condition setting unit that sets operating conditions of the air conditioning unit is further provided, The driver state detection device of claim 1 or 2, wherein the condition setting unit switches the air conditioning unit from the circulation mode to the intake mode when the concentration measuring unit measures a gas concentration equal to or greater than a second concentration threshold, which is a concentration threshold equal to or greater than the first concentration threshold, or when the concentration measuring unit measures a gas concentration equal to or greater than the first concentration threshold for a period equal to or greater than the time threshold.

5. the air conditioning unit is switchable between a low air volume mode and a high air volume mode in which the volume of air delivered into the vehicle cabin is greater than that in the low air volume mode, 5. The driver state detection device of claim 4, wherein the condition setting unit switches the air conditioning unit from the low air volume mode to the high air volume mode when the concentration measurement unit measures a carbon dioxide concentration equal to or greater than a third concentration threshold, which is a concentration threshold equal to or greater than the second concentration threshold, or when the concentration measurement unit measures a gas concentration equal to or greater than the first concentration threshold for a period of time equal to or greater than the time threshold.

6. The driver condition detection device according to claim 1 or 2, wherein the time threshold is set to be shorter as the first concentration threshold is larger.

7. Further, an occupant detection unit is provided to detect each occupant of the vehicle, The driver condition detection device according to claim 1 or 2, wherein the time threshold is set to be shorter as the number of occupants in the vehicle increases.

8. The driver state detection device according to claim 1 , wherein the time threshold is set to be shorter when the vehicle is in a parked state than when the vehicle is in a moving state.

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