JP4297155B2 - In-vehicle warning device - Google Patents

Description

  The present invention relates to an in-vehicle warning device that warns a driver using measurement results of a look-ahead time and a dozing time or an eye-closing time.

  Conventionally, a driver state detecting means for detecting a driver's looking-aside state and a dozing state, a timing means for measuring the duration of the driver's looking-aside state and a sleeping state, a vehicle speed detecting means for detecting a vehicle speed, and a preceding vehicle An inter-vehicle distance detecting means for detecting an inter-vehicle distance, an inter-vehicle time calculating means for calculating an inter-vehicle time with a preceding vehicle based on the vehicle speed detection value and the inter-vehicle distance detection value, and an allowable time at a predetermined inter-vehicle time. An allowable time setting means for searching and setting an allowable time corresponding to the calculated inter-vehicle time from a table of allowable time for an inter-vehicle time set in advance so as to be the maximum value, and the duration of the aside or doze state A side-by-side driving and dozing driving, characterized by comprising: a determination unit that determines that the driver is performing a side-by-side driving or a dozing driving when the allowable time set value is exceeded Broadcasting device is known (e.g., see Patent Document 1).

Also, a host vehicle speed detecting means for detecting the driving speed of the host vehicle, a preceding vehicle speed detecting means for detecting the driving speed of the preceding vehicle, and an inter-vehicle distance detecting means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle. And an alarm generating means for issuing an alarm to the driver when the relative speed of the host vehicle with respect to the preceding vehicle exceeds a predetermined allowable relative speed with respect to the inter-vehicle distance, and the driver's side-view driving and dozing Driving state detecting means for detecting driving, and when the side-by-side driving or dozing operation is detected, the allowable relative speed is corrected to be low, and the warning is issued when the corrected relative relative speed is exceeded. A preceding vehicle approach warning device characterized by this is known (for example, see Patent Document 2).
JP 2002-219968 A Japanese Patent No. 2583335

  In the invention described in the above-mentioned Patent Document 1, since the allowable time setting value for the duration of the aside state and the duration of the dozing state is determined according to the inter-vehicle time, the duration of the aside state and the duration of the dozing state The permissible time setting value for is the same value. However, since the look-ahead state and the dozing state are states having different characteristics, the alarm timing may not be appropriate in the configuration in which the alarm timing is determined based on the same determination criterion.

  Also, in the invention described in Patent Document 2 above, similarly, the alarm timing at the time of collision danger is determined without considering the respective characteristics of the looking-aside state and the dozing state. There is a risk that it will not be.

  Therefore, an object of the present invention is to provide an in-vehicle warning device capable of outputting an alarm at an appropriate alarm timing in consideration of the characteristics of the driver's looking-aside state and the dozing state or the closed-eye state.

In order to achieve the above object, a first invention relates to an in-vehicle warning device and relates to a vehicle based on a relationship between at least one physical quantity capable of representing a relative relationship between an object ahead of the vehicle and the own vehicle and a predetermined threshold. A collision danger state detection device for detecting a collision danger state between a front object and the own vehicle;
A warning output device that warns the driver when a dangerous collision state is detected by the dangerous collision state detection device;
A side-by-side time measuring device that measures the duration of the driver's side-by-side state;
A dozing time measuring device that measures the duration of the driver's dozing state,
A threshold changing device that changes the predetermined threshold in a direction in which a collision danger state is easily detected by the collision danger state detection device according to the measured look-aside time or dozing time;
In the threshold value changing device , the change amount of the predetermined threshold value with respect to the dozing time is larger than the change amount of the predetermined threshold value with respect to the look-aside time.

The second invention relates to the first invention,
The dozing time measuring device measures a duration time in which the driver's eyes are closed as the dozing time.

According to a third aspect of the present invention, a collision risk state between a vehicle front object and the host vehicle is detected based on a relationship between at least one kind of physical quantity capable of representing a relative relationship between the vehicle front object and the host vehicle and a predetermined threshold. A collision risk detection device that
A warning output device that warns the driver when a dangerous collision state is detected by the dangerous collision state detection device;
A side-by-side time measuring device that measures the duration of the driver's side-by-side state;
An eye-closing time measuring device that measures the time when the driver's eyes are closed;
A threshold value changing device that changes the predetermined threshold value in a direction in which a collision danger state is easily detected by the collision danger state detection device according to the measured look-ahead time or eye-closing time;
In the threshold value changing device , the change amount of the predetermined threshold value with respect to the eye closing time is larger than the change amount of the predetermined threshold value with respect to the looking-aside time.

The fourth invention relates to any one of the first to third inventions,
The looking-aside time measuring device measures a duration time in which the driver's face is not facing the front as the looking-aside time.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle-mounted warning apparatus which can output a warning at the appropriate warning timing in consideration of the driver | operator's looking-aside state and the characteristics of a dozing state or a closed eye state is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram exemplarily showing a main configuration of an alarm system including an in-vehicle alarm device according to Embodiment 1 of the present invention. The vehicle-mounted alarm device according to the present embodiment includes an alarm control ECU 110A, a driver monitor ECU 210, a driver monitor camera 212, an alarm ECU 230, and a buzzer 240.

  The alarm control ECU 110A has a hardware configuration mainly composed of an appropriate processor or microcomputer, and has a CPU that performs various processes described below, and programs and data used to perform various processes described below. It has a ROM, a readable / writable RAM for storing operation results, a timer, a counter, an input interface, an output interface, and the like. The hardware configurations of the other ECUs 210 and 230 may be the same, but, of course, the contents of the programs and data stored in the ROM (software configuration) differ depending on the processing contents.

  The alarm control ECU 110 </ b> A includes a side-view trigger count unit 112, a side-arm alarm necessity determination unit 114, a closed eye trigger count unit 116, and a doze alarm necessity determination unit 118 as functional blocks that realize main functions.

  A driver monitor ECU 210 is connected to the alarm control ECU 110A via an appropriate bus, and a driver monitor camera 212 is connected to the driver monitor ECU 210. Also, a white line detection ECU 290 is connected to the alarm control ECU 110A via an appropriate bus, and a white line recognition camera 292 is connected to the white line detection ECU 290. Further, a radar sensor 280 is connected to the alarm control ECU 110A via an appropriate bus. The alarm control ECU 110 </ b> A is connected to an alarm ECU 230 via a bus compliant with CAN (controller area network), and the alarm ECU 230 is connected to a buzzer 240. In the illustrated example, the brake ECU 250 is connected to the alarm control ECU 110A via a CAN-compliant bus, and the brake actuator 260 and the wheel side sensor 270 are connected to the brake ECU 250. In the illustrated example, the yaw rate sensor 272 and the steering sensor 274 are connected to the alarm control ECU 110A via a CAN-compliant bus. Note that these connection modes are not necessarily wired, and a part or all of them may be realized by a wireless communication path. In addition, each ECU 110, 210, 230 is configured as a separate unit for convenience, but a part or all of the functions of a certain ECU may be realized by another ECU, or a part of the functions of a certain ECU may be realized. It may be realized by another new ECU.

  The white line recognition camera 292 is provided at an appropriate location of the vehicle so that a road marking line (white line) can be captured on the road on which the vehicle travels. The white line recognition camera 292 may be arranged to image a road ahead of the vehicle and / or may be arranged to image a road behind the vehicle. The white line detection ECU 290 performs image processing on the image from the white line recognition camera 292 and detects the position of the road section line. There are various road section line detection methods, and a method of detecting a road section line by normal edge processing, a method of using a morphological operation, or the like may be used.

  The radar sensor 280 may be arranged, for example, to monitor an object ahead of the vehicle in the vicinity of the front grille of the vehicle or inside the front bumper. The radar sensor 280 radiates a detection wave, and receives a detection wave reflected by a vehicle front object (typically, a preceding vehicle) in the detection zone of the radar sensor 280 among the radiated detection waves. The distance of the object ahead of the vehicle from the own vehicle and the relative direction of the object ahead of the vehicle with respect to the own vehicle are detected. Further, on a curved road, the course of the host vehicle may be corrected using output signals from the yaw rate sensor 272 and the steering sensor 274. The detection wave emitted from the radar sensor 280 may be a light wave (for example, a laser wave), a radio wave (for example, a millimeter wave), or a sound wave (for example, an ultrasonic wave). A plurality of radar sensors 280 may be provided to monitor the rear of the vehicle and / or the side of the vehicle. Further, instead of or in addition to the radar sensor 280, the front of the vehicle and / or the rear of the vehicle and / or the side of the vehicle may be monitored using an image sensor (camera).

  The driver monitor camera 212 includes, for example, a color or infrared sensitive CCD (charge-coupled device) sensor array. The driver monitor camera 212 is provided at an appropriate position of the vehicle so that the front surface of the driver (for example, the driver's face from the front) can be captured. For example, the driver monitor camera 212 is installed on a dashboard of an instrument panel of a vehicle, a steering column, a room mirror, or the like. The driver monitor camera 212 acquires an image of the driver's face (hereinafter referred to as a “face image”) in real time while the vehicle is running, and is typically in a stream format of 30 fps (frame per second), and the driver monitor ECU 210. It may be that which supplies.

  The driver monitor ECU 210 performs image processing on the face image input from the driver monitor camera 212 as needed, and detects whether or not the driver's face is facing the front. There are various methods for detecting whether or not the driver's face is facing the front based on image processing, and any appropriate method may be used. For example, the position or orientation of each part of the face extracted as described above and the same part in each of the pre-stored postures (for example, the posture when facing the front, the posture looking left and right, up and down, etc.) By comparing the degree of matching with the position or orientation, the driver's current posture (face orientation) is detected. The orientation of the face may be represented by, for example, a rotation angle about three axes with the front direction of the face in a normal posture as one axis. When the face direction deviates from the front by a predetermined reference or more, it is determined that the driver's face is not facing the front. The driver monitor ECU 210 performs the above determination for each image frame, or performs the above determination for every predetermined number of consecutive image frames, and supplies the determination result to the alarm control ECU 110A for each determination cycle. In this example, the driver monitor ECU 210 sends a trigger signal (hereinafter referred to as “side-arm trigger”) indicating that to the alarm control ECU 110A for each determination cycle in which it is determined that the driver's face is not facing the front. Shall be supplied.

  The driver monitor ECU 210 also performs image processing on the face image input from the driver monitor camera 212 as needed, and determines whether or not the driver's eyes are closed based on the driver's eyelid opening amount (eyelid opening). To detect. There are various methods for detecting whether or not the driver's eyes are closed based on the image processing, and any appropriate method may be used. For example, for face images, face orientation and face size are corrected by affine transformation, etc., and then after edge processing, each face part is matched by matching processing of the face parts (mouth, nose, eyes). Is identified. Next, the maximum distance between the upper and lower eyelids (the eyelid opening) is obtained based on the feature amount of the eye part, that is, the coordinate sequence of the eyelid boundary line in this example. When the eyelid opening is equal to or less than a predetermined reference value, it is determined that the driver's eyes are closed. In this case, the predetermined reference value may be a value adapted for each driver. That is, the predetermined reference value is derived in advance by performing sensory evaluation, and is stored in a database for each driver. The driver monitor ECU 210 performs the above determination for each image frame, or performs the above determination for every predetermined number of consecutive image frames, and supplies the determination result to the alarm control ECU 110A for each determination cycle. In this example, the driver monitor ECU 210 supplies a trigger signal (hereinafter referred to as “closed eye trigger”) indicating the fact to the alarm control ECU 110A for each determination cycle in which it is determined that the driver's eyes are closed. And

  The look-aside trigger counting unit 112 of the alarm control ECU 110 </ b> A measures the duration of the driver's look-ahead state based on the look-aside trigger input from the driver monitor ECU 210. Specifically, the aside look trigger counting unit 112 increments a look aside counter value (initial value zero) when an aside look trigger is input in a certain determination cycle, and every time a look aside trigger is input in a subsequent determination cycle, The counter counter value is incremented. The look-aside trigger counting unit 112 basically counts up the look-aside trigger that is input at a continuous determination cycle. However, even if a certain momentary look-aside trigger discontinuity occurs, You may have the filter to hold | maintain. The look-ahead counter value corresponds to the duration of the driver's look-ahead state, that is, the look-aside time.

  The armpit alarm necessity determination unit 114 of the alarm control ECU 110A determines whether or not the current armpit alarm time exceeds the first predetermined time Ta [ms] for each determination period synchronized with the determination period of the driver monitor ECU 210. Specifically, the side-viewing alarm necessity determination unit 114 determines whether the side-by-side counter value exceeds a first predetermined threshold corresponding to the first predetermined time Ta each time the side-by-side counter value is incremented. When the look-aside counter value exceeds the first predetermined threshold, the look-ahead alarm necessity determination unit 114 determines that the look-ahead alarm is necessary, and issues a look-ahead warning command to the alarm ECU 230 so as to output a look-ahead alarm. Send. In addition, as conditions for transmitting the armpit warning command, other conditions (however, conditions related to eye closing time described later) may be added. For example, when the vehicle speed is equal to or higher than a predetermined value based on the wheel side sensor 270, or when the behavior of the vehicle is unstable based on the image recognition result of the road section line by the white line detection ECU 290 or the output value of the steering sensor 274 ( For example, it may be used as an AND condition for transmitting a warning command, such as when meandering in a manner that intermittently crosses a road section line.

  The alarm ECU 230 outputs an armpit warning via the buzzer 240 in response to the armpit alarm command from the armpit alarm necessity determination unit 114 of the alarm control ECU 110A. Note that the output form of the armpit warning is not limited to sound, and for example, a vibrating body embedded in the seat or the steering handle is vibrated, or a temperature changing means (such as a heater or a Peltier element) embedded in the seat or the steering handle is used. Or a sudden air blow of a large amount of air from the air outlet of the air conditioner, or automatically irradiating light toward the driver to alert the driver, or the brake ECU 250 causes the brake actuator 260 to Or to call attention by forced braking.

  The closed eye trigger count unit 116 of the alarm control ECU 110A measures the duration of the driver's sleep state based on the closed eye trigger input from the driver monitor ECU 210. Specifically, the closed eye trigger count unit 116 increments the closed eye counter value (initial value zero) when the closed eye trigger is input at a certain determination cycle, and each time the closed eye trigger is input at the subsequent determination cycle, The closed eye counter value is incremented. The eye-closing trigger counting unit 116 basically counts up the eye-closing triggers that are input at a continuous determination cycle. However, even when a certain instantaneous eye-closing trigger discontinuity occurs, You may have the filter to hold | maintain. The closed eye counter value corresponds to the duration of the closed eye state of the driver, that is, the closed eye time.

  The doze alarm necessity determination unit 118 of the alarm control ECU 110A determines whether or not the current eye closing time exceeds the second predetermined time Tb [ms] for each determination period synchronized with the determination period of the driver monitor ECU 210. Specifically, the dozing alarm necessity determination unit 118 determines whether the closed eye counter value exceeds the second predetermined threshold corresponding to the second predetermined time Tb each time the closed eye counter value is incremented by the closed eye trigger count unit 116. Determine whether or not. When the closed eye counter value exceeds the second predetermined threshold, the dozing alarm necessity determination unit 118 determines that the dozing alarm is necessary, and issues a dozing alarm command to the alarm ECU 230 so as to output the dozing alarm. Send. Note that other conditions (however, the conditions related to the above-mentioned look-aside time are excluded) may be added as conditions for transmitting the alarm command.

  The alarm ECU 230 outputs a dozing alarm via the buzzer 240 in response to the dozing alarm command from the dozing alarm necessity determination unit 118 of the alarm control ECU 110A. In addition, the output form of a dozing alarm is not restricted to a voice like the output aspect of an awakening alarm. Further, the output mode of the dozing alarm may be the same as or different from the output mode of the above-mentioned armpit alarm. When realizing the former, each warning command from warning control ECU110A may be the same signal.

  Here, in the present embodiment, the second predetermined time Tb that functions as a threshold for the above-mentioned eye closing time is set to be smaller than the first predetermined time Ta that functions as a threshold for the looking-aside time. This is because it takes time to reach an awakening state when the patient is in a dozing state. That is, in the dozing state, the response to the alarm tends to be delayed as compared with the side-viewing state in which the time required for such awakening is zero, and it is useful to output the alarm earlier by that much. For example, the first predetermined time Ta may be set to a time longer than the time required for the driver to confirm safety or confirm the display of the navigation device. Further, the second predetermined time Tb may be set to a time longer than a normal blinking time so that unnecessary alarms frequently occur due to blinking. For example, the second predetermined time Tb may be set to be longer than a normal blinking time and shorter than a time from when the driver's eyes are closed until the driver completely falls asleep. That is, the second predetermined time Tb may be set to a time that cannot be said to be a doze state. Even in such a closed state where it cannot be said that it is a dozing state, the pupil is opened by closing the eye, so there is a possibility that external recognition may be difficult until the pupil adapts to external light when the eye is opened. This is because it is useful to output an alarm earlier than in a state of looking aside without fear.

  FIG. 2 is a timing chart conceptually showing the difference between the second predetermined time Tb and the first predetermined time Ta. In FIG. 2, the horizontal axis represents time, and the vertical axis represents the output states of the aside trigger and the closed eye trigger. In the example illustrated in FIG. 2, a side-by-side trigger indicating that a side-by-side state is detected is continuously output from time t1. In addition, a dozing trigger indicating that a dozing state is detected is continuously output from time t2. In FIG. 2, the time t1 and the time t2 are set to the same time position for convenience of comparing the lengths of the second predetermined time Tb and the first predetermined time Ta.

  In the present embodiment, as described above, different thresholds (second predetermined time Tb, first predetermined time Ta) are set for the aside look time and the closed eye time, respectively, and each of the look aside state and the dozing state is set. The second predetermined time Tb is set smaller than the first predetermined time Ta according to the characteristics. Therefore, for example, as shown in FIG. 2, the time from the time when the dozing state starts to be detected until the time when the dozing alarm is output is the time from the time when the looking-aside state starts to be detected until the time when the armpit warning is output. Shorter than. That is, the alarm is output more quickly in the dozing state than in the aside state.

  Thus, according to the present embodiment, since the second predetermined time Tb is set to be smaller than the first predetermined time Ta as described above, the alarm is issued at an appropriate timing according to the respective characteristics of the looking-aside state and the dozing state. Can be output. In other words, for a dozing state where the response to the alarm is relatively slow, the alarm is output earlier than the look-aside state where the response to the alarm is relatively early. The alarm can be output with to ensure safety.

  The following modifications can be made to the first embodiment described above.

  For example, in the above-described embodiment, the duration of the driver's eye closed state (closed eye time) is measured as the duration of the driver's dozing state (sleeping time). Alternatively or in addition, measurements may be made using other parameters. For example, the measurement may be performed using various physiological characteristics such as an electroencephalogram, magnetoencephalography, heartbeat and heartbeat fluctuation, temperature of the driver's body surface, and changes thereof. Also in this case, the same effect as in the above-described embodiment can be obtained by setting the threshold for the duration of the dozing state, that is, the second predetermined time Tb, to be smaller than the first predetermined time Ta.

  FIG. 3 is a system configuration diagram exemplarily showing a main configuration of an alarm system including an in-vehicle alarm device according to Embodiment 2 of the present invention. Constituent elements denoted by the same reference numerals as those in the first embodiment described above may have the same configurations as those in the first embodiment unless otherwise specified.

  The alarm control ECU 110B includes a side-view trigger count unit 112, an eye-closed trigger count unit 116, a collision danger state detection unit 120, and a threshold value change unit 122 as functional blocks that realize main functions.

  The collision risk state detection unit 120 monitors the relative relationship between the vehicle front object and the host vehicle based on the information on the vehicle front object supplied from the radar sensor 280 every predetermined period, and determines the relationship between the vehicle front object and the host vehicle. Detects a collision risk condition. In this example, the collision risk state detection unit 120 calculates / monitors the inter-vehicle time between the vehicle front object and the own vehicle based on the information of the vehicle front object from the radar sensor 280 for each predetermined period, and calculates the calculated time. When the inter-vehicle time is less than the predetermined threshold Th, a collision risk state between the vehicle front object and the host vehicle is detected. Here, the inter-vehicle time is the time from the current time point to the time when a collision between the object ahead of the vehicle and the host vehicle is predicted to occur. It may be calculated by dividing by the relative speed between the vehicle front object and the own vehicle. As the predetermined threshold Th, a default value T0 is used unless a side-by-side trigger or a dozing trigger is output as described later. The default value T0 is preferably set within a time range that is sufficiently before the predicted collision time and has a high significance of the alarm output, and may be set to a time longer than the time from the collision unavoidable time to the predicted collision time, for example. . This setting mode of the default value T0 is suitable for a configuration in which the brake ECU 250 forcibly performs sudden braking or collision avoidance steering by an automatic steering mechanism (not shown) when a collision inevitable state is detected. In this case, even if the driver is informed of the collision inevitable state by a warning, the collision avoidance operation by the driver himself does not make sense, and the significance of the warning output is small. However, the default value T0 may be a time corresponding to a collision inevitable state.

  It should be noted that other conditions may be added to the detection condition of the collision risk state. For example, other conditions may include that the angle formed by the speed vector between the vehicle front object and the own vehicle is within a predetermined angle, or that the speed of the own vehicle is greater than or equal to a predetermined value.

  When the collision danger state detection unit 120 detects a collision danger state between the object ahead of the vehicle and the host vehicle, the collision danger state detection unit 120 transmits a collision danger warning command to the warning ECU 230 so as to output a collision danger warning.

  The alarm ECU 230 outputs a collision danger warning command via the buzzer 240 in response to the collision danger warning command from the collision danger state detection unit 120 of the warning control ECU 110B. The output form of the collision danger alarm command is not limited to sound, but for example, a vibrating body embedded in the seat or the steering handle is vibrated, or a temperature changing means (such as a heater or a Peltier element) embedded in the seat or the steering handle is used. A thermal stimulus is applied to the air conditioner, a large amount of air is blown suddenly from the air outlet of the air conditioner, light is automatically emitted to the driver to alert the driver, and the brake ECU 250 For example, the actuator 260 may be driven to call attention by forced braking.

  The threshold changing unit 122 changes the predetermined threshold Th from the default value T0 to a value that facilitates detection of a collision risk state by the collision risk state detection unit 120 according to the current look-ahead time and the eye-closing time. Specifically, the threshold changing unit 122 increases the predetermined threshold Th by an amount corresponding to the current look trigger count value and the closed eye trigger count value.

  Therefore, in this embodiment, when the driver is currently looking aside or falling asleep, the predetermined threshold T is increased according to the looking-aside time and the eye-closing time. The timing of falling below the threshold Th is earlier. That is, the alarm output timing is advanced, and so-called alarm advancement is realized.

  FIG. 4A is a diagram showing a change mode of the predetermined threshold Th according to the look-aside time, and FIG. 4B is a diagram showing a change mode of the predetermined threshold Th according to the eye closing time. 4A, the horizontal axis represents the look-ahead time, in FIG. 4B, the horizontal axis represents the closed eye time, and in FIGS. 4A and 4B, the vertical axis represents the predetermined threshold Th. Represents.

  As shown in FIG. 4A, the predetermined threshold Th increases toward the upper limit value Tx as the look-aside time increases. In the illustrated example, the predetermined threshold Th reaches the upper limit value Tx when the look-ahead time becomes Ta [ms], and maintains the upper limit value Tx even if the look-ahead time becomes Ta or more. Further, the predetermined threshold Th increases non-linearly with a downwardly convex curve as shown in FIG. 4A until the look-ahead time reaches Ta. Note that the value of the look-ahead time Ta is set in the same way as in the first embodiment. The upper limit value Tx is the time required for the driver's face to change from looking aside to a frontal state by an alarm and for the driver to recognize the front.

  As shown in FIG. 4B, the predetermined threshold Th increases toward the upper limit value Ty as the eye closure time increases. In the illustrated example, the predetermined threshold value Th reaches the upper limit value Tx when the eye closing time reaches Tb [ms], and maintains the upper limit value Ty even when the eye closing time becomes Tb or more. Further, the predetermined threshold Th increases non-linearly with an upwardly convex curve as shown in FIG. 4B until the closed eye time reaches Tb. The value of the eye closing time Tb is set based on the same concept as in the first embodiment, and Tb> Ta. The upper limit value Ty is the time required for the driver to return to his / her consciousness by an alarm from the dozing state (closed eyes in this example) and to recognize the front. Here, the upper limit value Ty is set to a value larger than the upper limit value Tx. This is because the time required for recognizing the front tends to be longer in the drowsiness state in which the consciousness is lower than in the side-viewing state due to its characteristics.

  Therefore, in this embodiment, the collision risk state is more easily detected by the collision risk state detection unit 120 when the dozing state is detected than when the side-by-side state is detected. Accordingly, the alarm output timing is earlier in the case where the dozing state is detected than in the case where the looking-aside state is detected.

  As described above, according to the present embodiment, focusing on the difference between the characteristics of the dozing state and the look-ahead state, by changing the way the alarm is output earlier between the dozing state and the look-ahead state, An alarm can be output at an appropriate timing according to the difference in characteristics. In other words, compared to the look-aside state, the dozing state in a state of reduced consciousness tends to take a longer time to recognize the front, so the warning in the case of the dozing state is earlier that much. Can be output.

  In this embodiment, even when the current look-ahead time is less than Ta or the current eye-close time is less than Tb, the alarm output timing is less than the upper limit value Tx and the upper limit value Ty, respectively. It is expedited. This is because even under such circumstances, it is highly possible that the driver is in a careless state ahead, and it is effective to issue warnings little by little.

  Here, as can be understood by comparing FIG. 4 (A) and FIG. 4 (B), in the present embodiment, the predetermined threshold value Th with respect to the look-aside time over the entire section from the horizontal axis 0 to Tb. The amount of change is smaller than the amount of change of the predetermined threshold Th with respect to the eye closing time. As shown in FIGS. 4A and 4B, this is achieved by setting the upper limit value Ty> the upper limit value Tx and the difference in the convex direction of the curve described above. According to such a configuration, according to the difference between the characteristics of the dozing state and the look-ahead state, the amount of alarm advance in the doze state is larger than the amount of alarm advance in the look-aside state, and according to the characteristics of each state Alarms can be sent out at an appropriate time.

  In the second embodiment, the “collision danger state detection device” in the claims is realized cooperatively by the radar sensor 280 and the collision danger condition detection unit 120 of the alarm control ECU 110B. The “warning output device” is realized cooperatively by the collision risk state detection unit 120, the warning ECU 230, and the buzzer 240 of the warning control ECU 110B, and the “side-viewing time measuring device” in the claims includes the driver monitor camera 212, the driver The “asleep time measuring device” or the “closed eye time measuring device” in the claims is realized cooperatively by the monitor ECU 210 and the armpit trigger counting unit 112 of the alarm control ECU 110B. Closed eyes of control ECU 110B Be realized cooperatively to the count unit 116, "the threshold change unit" in claims is implemented by the threshold changing unit 122 of the alarm control ECU110B.

  The following modifications can be made to the second embodiment described above.

  For example, in the above-described embodiment, the collision risk state is simply detected based on the relationship between the inter-vehicle time and the predetermined threshold Th, but may be detected by another method. For example, it may be detected using a two-dimensional map defined by the inter-vehicle distance between the vehicle front object and the host vehicle and the relative speed between the vehicle front object and the host vehicle. In this case, the two-dimensional map defines, for example, a threshold curve for dividing the collision risk state region and the non-collision risk state region, and the current inter-vehicle distance and the relative speed are set in the collision risk state region divided by the threshold curve. If it belongs, a collision danger state may be detected. Further, the danger state of collision may be detected using other physical quantities such as acceleration (deceleration) in addition to physical quantities such as inter-vehicle distance and relative speed.

  In the above-described embodiment, information representing the relative relationship between the object ahead of the vehicle and the host vehicle is acquired from the radar sensor 280. In addition to or instead of the information, similar information is acquired using an image sensor. Alternatively, when the vehicle front object includes a communication device capable of bidirectional communication, similar information may be acquired through the communication (for example, vehicle-to-vehicle communication).

  Further, in the above-described embodiment, for example, in the above-described embodiment, the closed eye time is measured as the dozing time. However, the dozing time is measured by using other parameters instead of or in addition to the driver's closed eyes. You may measure. For example, the measurement may be performed using various physiological features such as an electroencephalogram. Also in this case, by setting the increase amount of the predetermined threshold value Th with respect to the duration time of the dozing state to be larger than the increase amount of the predetermined threshold value Th with respect to the duration time of the looking-aside state, the same effect as the above-described embodiment can be obtained. it can.

  Further, in the above-described embodiment, as a preferred embodiment, the change curve of the predetermined threshold Th related to the aside state is convex downward until reaching the upper limit value Tx, and the change curve of the predetermined threshold Th related to the dozing state is Although convex upward until reaching the upper limit value Ty, only one of them may be realized. For example, only the change curve of the predetermined threshold Th related to the aside state may be convex downward, and the change curve of the predetermined threshold Th related to the dozing state may be a straight line, or conversely, only the change curve of the predetermined threshold Th related to the dozing state May be convex upward, and the change curve of the predetermined threshold Th related to the looking-aside state may be a straight line. Alternatively, the upper limit value Ty> the upper limit value Tx may be satisfied (that is, both the change characteristics of the predetermined threshold Th related to the aside state and the dozing state may be linear).

  Further, the above-described second embodiment can be combined with the above-described first embodiment. In this case, for example, when looking aside, if the looking-aside time is less than Ta, a collision danger alarm can be output by detecting a collision danger state. Become. However, even when the look-aside time becomes Ta or more, in addition to the look-aside alarm, a collision danger alarm may be additionally output when a collision danger state is detected. Such a configuration is particularly suitable when the output form of the collision danger alarm is different from the output form of the armpit warning.

The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added. The above-described first embodiment is a reference example that does not belong to the scope of the present invention.

1 is a system configuration diagram exemplarily showing a main configuration of an alarm system including an in-vehicle alarm device according to Embodiment 1 of the present invention. 3 is a timing chart conceptually showing a difference between a second predetermined time Tb and a first predetermined time Ta. It is a system block diagram which shows principally the main structure of the alarm system containing the vehicle-mounted alarm device which concerns on Example 2 of this invention. It is a figure which shows the change aspect of predetermined threshold value Th according to the looking-aside time and eye-closing time.

Explanation of symbols

110A, B Alarm control ECU
112 Aside look trigger count unit 114 Aside look alarm necessity determination unit 116 Eye-closed trigger count unit 118 Dozing alarm necessity determination unit 120 Collision danger state detection unit 122 Threshold change unit 210 Driver monitor ECU
212 Driver monitor camera 230 Alarm ECU
240 buzzer 250 brake ECU
260 Brake actuator 270 Wheel side sensor 272 Yaw rate sensor 274 Steering sensor 280 Radar sensor 290 White line detection ECU
292 White line recognition camera

Claims (4)

A collision risk state detection device for detecting a collision risk state between a vehicle front object and the own vehicle based on a relationship between at least one kind of physical quantity capable of expressing a relative relationship between the vehicle front object and the own vehicle and a predetermined threshold. When,
A warning output device that warns the driver when a dangerous collision state is detected by the dangerous collision state detection device;
A side-by-side time measuring device that measures the duration of the driver's side-by-side state;
A dozing time measuring device that measures the duration of the driver's dozing state,
A threshold changing device that changes the predetermined threshold in a direction in which a collision danger state is easily detected by the collision danger state detection device according to the measured look-aside time or dozing time;
Wherein the threshold changing unit, the change amount of the predetermined threshold for the snooze time, being larger than the change amount of the predetermined threshold for the inattentive time, vehicle warning device. The in-vehicle warning device according to claim 1 , wherein the dozing time measuring device measures a duration time in which the driver's eyes are closed as the dozing time. A collision risk state detection device for detecting a collision risk state between a vehicle front object and the own vehicle based on a relationship between at least one kind of physical quantity capable of expressing a relative relationship between the vehicle front object and the own vehicle and a predetermined threshold. When,
A warning output device that warns the driver when a dangerous collision state is detected by the dangerous collision state detection device;
A side-by-side time measuring device that measures the duration of the driver's side-by-side state;
An eye-closing time measuring device that measures the time when the driver's eyes are closed;
A threshold value changing device that changes the predetermined threshold value in a direction in which a collision danger state is easily detected by the collision danger state detection device according to the measured look-ahead time or eye-closing time;
Wherein the threshold changing unit, the change amount of the predetermined threshold value for the closing period is characterized by greater than the change amount of the predetermined threshold for the inattentive time, vehicle warning device.   The in-vehicle warning device according to any one of claims 1 to 3, wherein the aside time measuring device measures a duration time in which the driver's face is not facing the front as the aside time.

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