Vehicle driver condition determination device

Abstract

To provide a vehicle driver state determination device capable of correctly determining a state of a driver and also suppressing a cost increase.SOLUTION: A vehicle driver state determination device includes: an imaging section for imaging a driver of a vehicle; a pupil diameter detection section for detecting information related to a pupil diameter of the driver from an image acquired by imaging of the imaging section; an eye-opening state detection section for detecting information related to an eyelid position of the eye of the driver; and a driver state determination section for executing state determination processing to determine the state of the driver based on the information related to the pupil diameter detected by the pupil diameter detection section and the information related to the pupil position detected by the eye-opening state detection section. The driver state determination section excludes the information related to the pupil diameter and the information related to the pupil position which are synchronously detected from an object of the state determination processing on condition that the change of the pupil diameter is synchronized with the change of the pupil position due to closing the eyelid.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a driver's state determination device for a vehicle. [Background technology]

[0002] 2. Description of the Related Art Conventionally, driver state determination devices for vehicles have been proposed (see, for example, Patent Documents 1 to 5).

[0003] The above-mentioned Patent Document 1 discloses an information processing device that estimates a user's state based on biological information such as a pupil diameter acquired from the user. The above-mentioned Patent Document 1 describes that a reference pupil diameter (reference pupil diameter) is calibrated based on measurement conditions such as the amount of ambient incident light or the gaze point for measuring the user's pupil diameter, and a reference pupil diameter appropriate for the measurement conditions is set to estimate the user's state. The above-mentioned Patent Document 1 also describes that when the measured pupil diameter is larger than the reference pupil diameter, it can be estimated that the user is in an excited state, and when the measured pupil diameter is smaller than the reference pupil diameter, it can be estimated that the user is in a fatigued (sleepy) state.

[0004] The above-mentioned Patent Document 2 discloses a visibility support device for a vehicle that appropriately ensures the driver's visibility when driving at night, etc. The above-mentioned Patent Document 2 describes that the face of the driver of the vehicle is imaged by an imaging device, the pupil diameter of the driver is obtained from the image, and the illumination range of the headlights is determined based on the pupil diameter of the driver by referring to an illumination range map that specifies the relationship between the pupil diameter and the illumination range of the headlights.

[0005] The above-mentioned Patent Document 3 discloses a driver state determination device that determines the state of the driver based on the change in the diameter of the driver's pupil by utilizing an illumination unit (for example, the blinking of a turn signal lamp) provided in the vehicle. The above-mentioned Patent Document 3 describes that if the amount of change in the pupil diameter caused by the light from the illumination unit provided in the vehicle is less than a predetermined value, the driver is determined to be in a tense state, and if the amount of change in the pupil diameter caused by the light from the illumination unit provided in the vehicle is equal to or greater than a predetermined value, the driver is determined to be in a relaxed state.

[0006] The above-mentioned Patent Document 4 discloses an information processing device that uses the detection results of the user's pupil diameter and eyelid opening and closing interval to determine the user's stress level. The above-mentioned Patent Document 4 describes that image recognition is performed on a captured image of the user's eyes to detect the user's eye movements such as the pupil diameter and eyelid opening and closing interval, and the presence or absence of the user's stress symptoms is determined based on the detection results.

[0007] The above-mentioned Patent Document 5 discloses a driver state determination device that determines whether or not the driver is aware of a sense of danger. The above-mentioned Patent Document 5 describes that it detects whether or not the driver's heart rate is continuously increasing and whether or not the driver's blink interval is longer than necessary, and determines whether or not the driver is aware of a sense of danger based on these detection results. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2018 / 100875 [Patent Document 2] JP 2009-113622 A [Patent Document 3] JP 2016-139258 A [Patent Document 4] JP 2019-40495 A [Patent Document 5] JP 2015-32005 A Summary of the Invention [Problem to be solved by the invention]

[0009] The above Patent Documents 1 to 5 disclose techniques for providing driving assistance based on biological information such as changes in the pupil diameter of the driver. However, due to sunlight from the setting sun and light with high incidence from one direction such as the light source of the headlights of oncoming vehicles, the brightness outside the vehicle may not be equal to the brightness inside the vehicle. For example, the brightness actually perceived by the driver may not be detected only by information from an exterior illuminance sensor for controlling headlights arranged at a predetermined position.

[0010] As described above, when trying to obtain a decline in the driver's own cognitive function based on a change in the driver's pupil diameter, it is difficult to perform pupil diameter calibration in the light and dark outside the vehicle. Therefore, there is a concern that a change in pupil diameter due to disturbance light cannot be distinguished from a change in pupil diameter due to a decline in the driver's cognitive function, resulting in an erroneous determination, and there is a problem in that the driver's condition cannot be accurately determined.

[0011] On the other hand, it is possible to accurately obtain the illuminance state inside the vehicle cabin by providing a plurality of illuminance sensors near the driver inside the vehicle cabin, but this has the problem of being costly.

[0012] The present invention has been made to solve the above problems, and aims to provide a driver's state determination device for a vehicle that can accurately determine the driver's state while preventing costs from increasing. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention is configured as follows.

[0014] (1) A driver's state determination device for a vehicle according to the present invention comprises an imaging unit that images a driver of the vehicle, a pupil diameter detection unit that detects information related to the driver's pupil diameter from an image acquired by imaging by the imaging unit, an eye open state detection unit that detects information related to the position of the driver's eyelids, and a driver state determination unit that performs a state determination process to determine the state of the driver based on the information related to the pupil diameter detected by the pupil diameter detection unit and the information related to the eyelid position detected by the eye open state detection unit, and is characterized in that, on the condition that the change in pupil diameter and the change in eyelid position due to closing of the eyelids are synchronized, the driver state determination unit excludes the information related to the pupil diameter and the information related to the eyelid position detected at the time of synchronization from the target of the state determination process.

[0015] According to the above configuration, when the change in the pupil diameter and the change in the eyelid position of the driver are synchronized at the reflex level (reflexive blinking, etc.), it can be determined that the change is due to an influence (disturbance factor) of light or the like entering the driver's eyes. As a result, when the change in the pupil diameter and the change in the eyelid position are synchronized, the change in the pupil diameter can be determined not to be due to the driver's fatigue or a decline in cognitive function, etc. As a result, the driver's condition can be accurately determined. Furthermore, since it is no longer necessary to separately install a device, etc. for accurately acquiring the illuminance condition inside the vehicle, it is possible to suppress high costs.

[0016] (2) In the driver state determination device of the present invention, preferably, the eye-open state detection unit is capable of deriving an eyelid closure rate based on the eyelid position, and the driver state determination unit determines that the change in eyelid position has occurred due to the eyelids being closed based on the eyelid closure rate and the duration during which the eyelid closure rate continues at or above a predetermined value. With this configuration, it is possible to accurately determine whether a change in the driver's eyelid position is normal or abnormal based on the eyelid closure rate and the duration.

[0017] (3) In this case, preferably, the driver state determination unit may exclude the information related to the pupil diameter and the information related to the eyelid position detected at the time of synchronization from the target of the state determination process, on the condition that the change in the pupil diameter and the change in the eyelid position are synchronized when the contraction rate before and after the change in the pupil diameter is equal to or greater than a first threshold value and the contraction rate before and after the opening and closing of the eyelid position is equal to or greater than a second threshold value and continues for the duration. With this configuration, when the change in the pupil diameter and the change in the eyelid position are synchronized at the contraction rate and duration, etc., it is determined that the change in the pupil diameter and the change in the eyelid position of the driver are influenced by disturbances such as light stimuli (disturbance factors). Therefore, when there is a change in the pupil diameter and the change in the eyelid position as described above, it is possible to suppress an immediate erroneous determination that the driver's state is abnormal.

[0018] (4) The driver state determination device of the present invention may preferably further include an exterior illuminance sensor that detects illuminance outside the vehicle, and the driver state determination unit may exclude the information related to the pupil diameter and the information related to the eyelid position from the state determination process on the condition that the exterior illuminance sensor detects that the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value. With this configuration, when the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value, it can be determined that the driver's pupil diameter and eyelid position have changed reflexively because the illuminance has suddenly increased. As a result, it is possible to suppress erroneous determination that the change in the driver's pupil diameter and eyelid position due to a sudden increase in illuminance is an abnormal state. Effect of the Invention

[0019] According to an aspect of the present invention, it is possible to provide a driver's state determination device for a vehicle that can accurately determine the driver's state while suppressing increases in costs. [Brief description of the drawings]

[0020] [Figure 1] 1 is a block diagram showing an overall configuration of a driver's state determination device for a vehicle according to an embodiment of the present invention; [Diagram 2] 1 is a graph for explaining a decline in cognitive function based on interpupillary distance (change in pupil diameter) according to this embodiment. [Diagram 3] 4 is a flowchart showing a state determination process in the driver state determination device for a vehicle according to the present embodiment. [Figure 4] 4 is a flowchart showing a state determination process in the driver state determination device for a vehicle according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, a driver state determination device for a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings. These drawings are schematic diagrams and are not necessarily drawn to exact scale. In addition, in the drawings, similar components are indicated by the same reference numerals.

[0022] (Overall composition) The overall configuration of a vehicle driver state determination device 100 according to this embodiment will be described with reference to Fig. 1. The vehicle driver state determination device 100 is applied to (mounted on) general vehicles such as hybrid cars, electric cars, and self-driving cars. As shown in Fig. 1, the vehicle driver state determination device 100 includes an imaging unit 10, a sensor unit 20, a control unit 30, and a notification unit 40.

[0023] (Imaging unit) The imaging unit 10 is mainly composed of a driver monitoring camera 10a. The driver monitoring camera 10a is composed of a camera unit such as a so-called drive recorder. The driver monitoring camera 10a is attached to, for example, the windshield or the rearview mirror in the vehicle interior.

[0024] The driver monitoring camera 10a captures an image of the face (particularly the area around the eyes) of the driver who drives the vehicle. The driver monitoring camera 10a transmits image information (data) of the captured face of the driver to a calculation system 31 of the control unit 30, which will be described later. The driver monitoring camera 10a may also be equipped with an infrared light. This makes it possible to capture a clear image of the driver's face even in a dark vehicle interior, such as when driving at night.

[0025] (Sensor section) The sensor unit 20 is mainly composed of an exterior illuminance sensor 20a. The exterior illuminance sensor 20a is provided on the outer periphery of the vehicle and detects the illuminance outside the vehicle. The exterior illuminance sensor 20a transmits the detected illuminance information (data) outside the vehicle to a calculation system 31 of the control unit 30, which will be described later.

[0026] (Control unit) The control unit 30 is a control device that controls the entire vehicle, etc. The control unit 30 includes a calculation system 31 and a vehicle control system 32.

[0027] The calculation system 31 detects information related to the driver's pupil diameter and eyelid position based on the illuminance information detected by the outside illuminance sensor 20a of the sensor unit 20 and the image information of the driver's face captured by the driver monitoring camera 10a of the imaging unit 10. Furthermore, the calculation system 31 determines whether the driver is in a normal state or an abnormal state based on the above information and transmits the determination result to the vehicle control system 32.

[0028] The calculation system 31 includes a pupil diameter detection unit 31a, an eye open state detection unit 31b, and a driver state determination unit 31c.

[0029] The pupil diameter detection unit 31a detects information related to the driver's pupil diameter (e.g., the size of the pupil diameter and the rate of change due to enlargement and contraction of the pupil diameter) from the image information acquired by imaging with the driver monitoring camera 10a of the imaging unit 10.

[0030] The eye-open state detection unit 31b detects information related to the driver's eyelid position (e.g., the distance between the upper eyelid and the lower eyelid) from image information acquired by imaging with the driver monitoring camera 10a of the imaging unit 10. The eye-open state detection unit 31b can also derive the eyelid closure rate based on the eyelid position. The eyelid closure rate refers to the rate of change in the distance of the eyelid in the blinking direction (vertical direction). The driver state determination unit 31c also determines that a change in eyelid position (closing of eyelid position) has occurred due to the eyelids being closed, based on the eyelid closure rate and the duration during which the eyelid closure rate continues at or above a predetermined value.

[0031] Here, in this embodiment, the driver state determination unit 31c performs a state determination process to determine whether the driver is in a normal state or an abnormal state based on information related to the pupil diameter detected by the pupil diameter detection unit 31a and information related to the eyelid position detected by the eye-open state detection unit 31b. Also, in this embodiment, the driver state determination unit 31c performs a process to exclude information related to the pupil diameter and information related to the eyelid position detected at the time of synchronization from the state determination process on the condition that the change in the pupil diameter and the change in the eyelid position due to the closing of the eyelids are synchronized.

[0032] Specifically, the driver state determination unit 31c determines whether or not the change in pupil diameter and the change in eyelid position are synchronized when the contraction rate before and after the change in pupil diameter is equal to or greater than a first threshold (e.g., 15% or more) and the contraction rate before and after the opening and closing of the eyelid position (eyelid closing rate) is equal to or greater than a second threshold (e.g., 10% or more) and continues for a predetermined duration. On the condition that the change in pupil diameter and the change in eyelid position are determined to be synchronized, the driver state determination unit 31c excludes information related to the pupil diameter and the eyelid position detected at the time of synchronization from the target of the state determination process. This is because in the above case, the change in the driver's pupil diameter and the change in eyelid position are determined to be due to disturbance factors such as sunlight outside the vehicle and the light source of the headlights of an oncoming vehicle, and are not due to a decline in the driver's cognitive function (degree of recognition).

[0033] Here, the determination of the decline in cognitive function of the driver will be described with reference to Fig. 2. Fig. 2 shows the change in the interpupillary distance (change in pupil diameter) of the driver over time, with the horizontal axis showing time [min] and the vertical axis showing the interpupillary distance [mm].

[0034] In FIG. 2, the interpupillary distance changes over time, repeating micro-vibrations. In addition, the amplitude of the interpupillary distance is different between a range of 5 min or less (monotonous pupil constriction) and a range of 5 min or more (low-frequency fluctuation), with the border at approximately 5 min in time. In other words, the amplitude of the interpupillary distance is larger in the range of 5 min or more than in the range of 5 min or less. Note that "monotonous pupil constriction" indicates a state before drowsiness occurs (normal state), and "low-frequency fluctuation" indicates a precursor to drowsiness or a state of high drowsiness (high drowsiness state).

[0035] When the driver's cognitive impairment is approximately equal to the driver's high drowsiness state (deterioration of cognitive impairment ≈ high drowsiness state), the deterioration of cognitive impairment causes monotonic pupil constriction and low-frequency fluctuations in pupil diameter. In this embodiment, as described above, by detecting information related to pupil diameter over time (change in pupil diameter), it is possible to determine the deterioration of the driver's cognitive impairment from the change in pupil diameter.

[0036] As shown in Fig. 1, the driver state determination unit 31c excludes information related to pupil diameter and information related to eyelid position from the state determination process on the condition that the vehicle exterior illuminance sensor 20a detects that the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value. In the above case, the change in the driver's pupil diameter and eyelid position is determined to be a disturbance factor due to sunlight outside the vehicle or the light source of the headlights of an oncoming vehicle.

[0037] The vehicle control system 32 is a control device that controls the vehicle based on the determination result determined by the driver state determination unit 31c of the calculation system 31. For example, on condition that the driver state determination unit 31c determines that the driver is in a normal state, the vehicle control system 32 performs a process to continue the traveling of the vehicle. On the other hand, on condition that the driver state determination unit 31c determines that the driver is in an abnormal state, the vehicle control system 32 performs a process to stop the vehicle and / or a process to output an alert to the notification unit 40.

[0038] (Notification Department) The notification unit 40 is mainly composed of a speaker, an instrument panel, etc. When the driver is in an abnormal state (not in a normal state), the notification unit 40 audibly and visually notifies (warns) the driver by a buzzer, voice, light, text, etc.

[0039] (Status determination process) The state determination process in the driver state determination device for a vehicle according to this embodiment will be described with reference to Figs. 1, 3, and 4.

[0040] 3, in step S10, the vehicle driving state is controlled by the vehicle control system 32. Then, the process proceeds to step S11.

[0041] In step S11, the vehicle exterior illuminance sensor 20a measures (detects) the illuminance outside the vehicle, and transmits illuminance information (data) outside the vehicle to the calculation system 31. After that, the process proceeds to step S12.

[0042] In step S12, the driver's face is imaged by the driver monitoring camera 10a, and information related to the driver's pupil diameter and eyelid position is detected from the image. At this time, the information related to the pupil diameter is calibrated based on the illuminance information (data) outside the vehicle detected in step S11. For example, if a certain pupil diameter continues for a predetermined period of time due to the setting sun or the like, calibration is performed using that pupil diameter as a reference diameter, and the driver's state due to the change in pupil diameter is determined.

[0043] The information on the pupil diameter is detected by the pupil diameter detection unit 31a from the image captured by the driver monitoring camera 10a. The information on the eyelid position is detected by the eye open state detection unit 31b from the image captured by the driver monitoring camera 10a. The processes in steps S11 and S12 are performed substantially simultaneously. Then, the process proceeds to step S13.

[0044] In step S13, the driver state determination unit 31c determines whether the contraction rate before and after the change in pupil diameter is equal to or greater than a first threshold value (e.g., 15% or greater). In step S13, if the driver state determination unit 31c determines that the contraction rate before and after the change in pupil diameter is not equal to or greater than 15% (less than 15%) (No), the process returns to step S10.

[0045] On the other hand, if it is determined in step S13 by the driver state determination unit 31c that the contraction rate before and after the change in pupil diameter is 15% or more (Yes), the process proceeds to step S14.

[0046] In step S14, the driver state determination unit 31c determines whether the reduction rate (eyelid closure rate) of the eyelid position before and after opening and closing is greater than or equal to a second threshold value (e.g., greater than or equal to 10%) and whether the change in eyelid position continues for a predetermined duration.

[0047] In step S14, if the driver state determination unit 31c determines that the reduction rate of the eyelid position before and after opening and closing is not 10% or more (less than 10%), or that the change in eyelid position has not continued for a specified duration (No), the process returns to step S10.

[0048] On the other hand, in step S14, if the driver state determination unit 31c determines that the reduction rate of the eyelid position before and after opening and closing is 10% or more and that the change in eyelid position (closing of eyelid position) continues for a predetermined duration (Yes), the process proceeds to step S15 (see Figure 4).

[0049] The order of steps S13 and S14 may be reversed, or the respective steps may be performed substantially simultaneously. After it is determined in step S13 that the change in pupil diameter is a reduction equal to or greater than the first threshold, step S14 may be omitted and the process may proceed to step S15.

[0050] In step S15, the exterior illuminance sensor 20a detects the illuminance outside the vehicle, and the detected illuminance information (data) is transmitted to the calculation system 31 of the control unit 30. The driver state determination unit 31c of the calculation system 31 determines whether the illuminance detected by the exterior illuminance sensor 20a is equal to or greater than a predetermined illuminance value (rapid increase in illuminance).

[0051] In step S15, if the driver state determination unit 31c determines that the illuminance detected by the exterior illuminance sensor 20a is equal to or greater than a predetermined illuminance value (Yes), the process proceeds to step S16.

[0052] In step S16, it is determined that the change in the driver's pupil diameter and eyelid position is due to disturbance factors such as sunlight and headlights of oncoming vehicles, and is not due to a decline in the driver's cognitive function, so information related to the driver's pupil diameter and information related to the eyelid position are excluded from the state determination process (determination canceled). Then, the process returns to step S10 (see FIG. 3).

[0053] On the other hand, if the driver state determination unit 31c determines in step S15 that the illuminance detected by the exterior illuminance sensor 20a is less than the predetermined illuminance value (No), the process proceeds to step S17.

[0054] In this embodiment, in step S17, the driver state determination unit 31c determines whether the change in the pupil diameter and the change in the eyelid position of the driver are synchronized. The "synchronization" in step S17 may be set to, for example, a time of a reflex reaction level, which is about 0.1 seconds in this embodiment, but this time can be set appropriately. In addition, in step S17, if the change in the pupil diameter and the change in the eyelid position are synchronized (Yes), the process proceeds to step S16.

[0055] In step S16, the driver state determination unit 31c determines that the change in the driver's pupil diameter and eyelid position is due to disturbance factors such as sunlight and headlights of oncoming vehicles, and is not due to a decline in the driver's cognitive function, and therefore excludes information related to the driver's pupil diameter and information related to the eyelid position from the state determination process (determination canceled). Then, the process returns to step S10 (see FIG. 3).

[0056] On the other hand, in step S17, if the driver state determination unit 31c determines that the change in the pupil diameter and the change in the eyelid position of the driver are not synchronized (No), the process proceeds to step S18. That is, this is the case when the change in the pupil diameter and the change in the eyelid position of the driver do not occur simultaneously.

[0057] In step S18, the driver state determination unit 31c determines that the diameter of the driver's pupil has changed (constricted), and then the process proceeds to step S19.

[0058] In step S19, the driver state determination unit 31c determines whether the change in the driver's pupil diameter is abnormal. If the driver state determination unit 31c determines in step S19 that the change in the driver's pupil diameter is abnormal (Yes), the process proceeds to step S20. In this case, the change in the pupil diameter is determined to be due to the driver's fatigue, a decline in cognitive function, or the like.

[0059] In step S20, vehicle control is performed by the vehicle control system 32. Specifically, the vehicle control system 32 performs a process of stopping the vehicle and / or a process of outputting an alert to the notification unit 40. After that, the process returns to step S10.

[0060] On the other hand, if it is determined in step S19 that the change in the pupil diameter of the driver is not abnormal (No), the process proceeds to step S21. In step S21, the vehicle control system 32 performs a process to continue the running of the vehicle. Then, the process returns to step S10.

[0061] According to the embodiment described above, the following advantages (1) to (4) can be obtained.

[0062] (1) In the vehicle driver state determination device 100 according to the above embodiment, on the condition that the change in the pupil diameter and the change in the eyelid position of the driver are synchronized, the information related to the pupil diameter and the information related to the eyelid position detected at the time of synchronization are excluded from the target of the state determination process by the driver state determination unit 31c. According to the above embodiment, when the change in the pupil diameter and the change in the eyelid position of the driver are synchronized at the reflex level (reflexive blinking, etc.), it can be determined that the change is due to an influence (disturbance factor) of light or the like that has entered the driver's eyes. As a result, when the change in the pupil diameter and the change in the eyelid position are synchronized, the change in the pupil diameter can be determined not to be due to the driver's fatigue or a decline in cognitive function, etc. As a result, the driver's state can be accurately determined. Furthermore, since it is not necessary to separately install a device or the like for accurately acquiring the illuminance state in the vehicle cabin, it is possible to suppress high costs.

[0063] (2) In the vehicle driver state determination device 100 according to the above embodiment, a change in eyelid position is determined to have occurred due to eyelid closure when the eyelid closure rate is 10% or more and for a predetermined duration. This makes it possible to accurately determine whether a change in the driver's eyelid position is normal or abnormal based on the eyelid closure rate and duration.

[0064] (3) In the vehicle driver state determination device 100 according to the above embodiment, when the reduction rate before and after the change in the driver's pupil diameter is equal to or greater than the first threshold (15% or more) and the reduction rate before and after the opening and closing of the eyelid position is equal to or greater than the second threshold (10% or more) and continues for a predetermined duration, the information related to the pupil diameter and the eyelid position detected at the time of synchronization is excluded from the target of the state determination process by the driver state determination unit 31c, on the condition that the change in the pupil diameter and the change in the eyelid position are synchronized. As a result, when the change in the pupil diameter and the change in the eyelid position are synchronized at the above reduction rate and duration, it is determined that the change in the driver's pupil diameter and the change in the eyelid position are due to the influence of disturbances such as light stimuli (disturbance factors). Therefore, when the above-mentioned change in the pupil diameter and the change in the eyelid position occur, it is possible to suppress the driver's state from being erroneously determined to be abnormal immediately.

[0065] (4) In the driver state determination device 100 of the vehicle according to the above embodiment, information related to the pupil diameter and information related to the eyelid position are excluded from the state determination process by the driver state determination unit 31c on the condition that the vehicle exterior illuminance sensor 20a detects that the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value. As a result, when the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value, it can be determined that the driver's pupil diameter and eyelid position have changed reflexively due to a sudden increase in illuminance. As a result, it is possible to prevent the driver's pupil diameter and eyelid position from being erroneously determined to be abnormal due to a sudden increase in illuminance.

[0066] (Modification) The above embodiment can be modified as follows.

[0067] In the above embodiment, the driver monitoring camera is shown as an example of an imaging unit that captures an image of the driver of the vehicle, but the present invention is not limited to this. For example, an imaging unit other than the driver monitoring camera can be applied as long as it is capable of capturing an image of the driver of the vehicle.

[0068] In the above embodiment, an example is shown in which it is determined whether the reduction rate before and after the change in the pupil diameter of the driver is equal to or greater than the first threshold value (for example, 15% or more), but the present invention is not limited to this. For example, the first threshold value can be set to a value other than 15%.

[0069] In the above embodiment, an example is shown in which it is determined whether the reduction rate before and after the change in the driver's eyelid position is equal to or greater than the second threshold (for example, 10% or more), but the present invention is not limited to this. For example, the second threshold can be set to a value other than 10%.

[0070] The above-described embodiments are merely examples of the application of the present invention, and it goes without saying that any other embodiments within the scope of the claims are also included in the technical scope of the invention. [Explanation of symbols]

[0071] 10: Imaging unit 10a: Driver monitoring camera 20: Sensor section 20a: Exterior illuminance sensor 30: Control section 31: Computing Systems 31a: Pupil diameter detection unit 31b: Eye open state detection unit 31c: Driver state determination unit 32: Vehicle control system 40: Information Department 100: Vehicle driver state determination device

Claims

1. An imaging unit that images a driver of the vehicle; a pupil diameter detection unit that detects information related to a pupil diameter of the driver from an image acquired by the imaging unit, and an eye open state detection unit that detects information related to an eyelid position of the driver; a driver state determination unit that performs a state determination process to determine a state of the driver based on information related to the pupil diameter detected by the pupil diameter detection unit and information related to the eyelid position detected by the eye open state detection unit, the driver state determination unit excludes information related to the pupil diameter and information related to the eyelid position detected at the time of synchronization from targets of the state determination process on the condition that the change in the pupil diameter and the change in the eyelid position due to closing of the eyelids are synchronized; the eye-open state detection unit is capable of deriving an eyelid closure rate based on the eyelid position, the driver state determination unit determines that a change in eyelid position has occurred due to the eyelids being closed, based on the closure rate and a duration during which the closure rate continues to be equal to or greater than a predetermined value, The driver's state determination device for a vehicle is characterized in that, when the reduction rate before and after the change in pupil diameter is equal to or greater than a first threshold value and the reduction rate before and after the opening and closing of the eyelid position is equal to or greater than a second threshold value and continues for the duration, the driver's state determination unit excludes information related to the pupil diameter and information related to the eyelid position detected at the time of synchronization, on the condition that the change in pupil diameter and the change in eyelid position are synchronized, from the target of the state determination processing.

2. Further comprising an exterior illuminance sensor for detecting an illuminance outside the vehicle, 2. The driver's state determination device for a vehicle as described in claim 1, characterized in that, when the exterior illuminance sensor detects that the illuminance outside the vehicle is equal to or greater than a predetermined illuminance value, the driver's state determination unit excludes the information relating to the pupil diameter and the information relating to the eyelid position from the state determination processing.

3. A driver state determination device for a vehicle as described in Claim 2, characterized in that the reference diameter related to the pupil diameter is calibrated based on illuminance information from the exterior illuminance sensor.

Images