JP2012234305A - Consciousness deterioration determining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a consciousness deterioration determination device capable of accurately determining an inattentive state due to deviation from no steering.
SOLUTION: Road information acquisition means and vehicle information acquisition means acquire road information and driving information of a road on which a vehicle is traveling (step S1), and a deviation risk determination means acquires acquired road information, A deviation risk MLC from the travel lane of the vehicle is calculated based on the travel information (step S2), and the determination unit determines that the departure risk MLC is large (step S3) and the detected actual yaw rate is small (step S4). ) Is in a no-steering deviation state (step S5), and it is determined that the driver is in a state of reduced consciousness.
[Selection] Figure 2

Description

  The present invention relates to a consciousness decrease determination device that determines a consciousness decrease state of a driver of a vehicle.

  2. Description of the Related Art Conventionally, a technique disclosed in Patent Document 1 is known as a technique for determining a state where a driver's consciousness is lowered. This technique detects a driver's careless state (a state of reduced consciousness) based on the driving operation state of the driver of the vehicle. Specifically, it is described that it is determined that the driver is in an inadvertent state when the steering operation is performed at a steering angle and / or steering speed of a predetermined level or more from a non-steering state where the steering operation is not performed. Yes. That is, the driver's careless state is determined based on excessive steering from the non-steering state.

Special table 2008-542935 gazette

  However, in places where there are many road disturbances such as irregularities, the steering system may vibrate due to this disturbance, and the steering state may be determined even though the driver is not actually steering. If the non-steering state cannot be correctly determined in this way, an inattentive state due to no steering deviation cannot be correctly determined.

  Therefore, an object of the present invention is to provide a consciousness deterioration determination device that can accurately determine an inattention state due to a deviation from no steering.

  In order to solve the above-mentioned problems, a consciousness decrease determination device according to the present invention is a consciousness decrease determination device that determines whether or not a driver of a vehicle is in a consciousness decrease state. Road information acquisition means for acquiring road information; (2) vehicle information acquisition means for acquiring vehicle travel information; and (3) a risk of departure from the vehicle lane based on the acquired road information and travel information. (4) a driver's consciousness when the determined departure risk is greater than a preset threshold value and the detected actual yaw rate is less than a preset threshold value; And a determination unit that determines that the state is in a lowered state. That is, when the actual yaw rate is small, the vehicle is regarded as being in a non-steering state.

  The determination unit may not perform the determination of the consciousness reduction state when the curve radius of the travel lane is equal to or less than a preset threshold value.

  According to the present invention, no-steering deviation can be accurately determined by using the deviation risk and the actual yaw rate as indices. In particular, even when the steering is vibrated due to the influence of road surface disturbance, it is possible to correctly determine the non-steering state without being affected by this, so it is also possible to correctly determine the inattentive state due to no steering deviation. it can.

  In a case where the curve radius is small, that is, in a sharp curve, the fluctuation of the actual yaw rate when performing out-in-out traveling may be small. Therefore, when the curve radius is small, the determination of no steering deviation is not performed, so that it is possible to reduce erroneous determination of deviation from the course that occurs during out-in-out traveling as no steering deviation.

It is a block diagram which shows the structure of one Embodiment of the consciousness fall determination apparatus which concerns on this invention. It is a flowchart which shows the determination process in the apparatus of FIG. It is a graph which shows the example of a time change of each variable at the time of the process of FIG. It is a flowchart which shows another embodiment of the determination process in the apparatus of FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.

  FIG. 1 is a block configuration diagram showing an overview of a consciousness deterioration determining apparatus 100 according to an embodiment of the present invention. This consciousness reduction determination device 100 is a device that is mounted on a vehicle and determines whether or not the consciousness of the driver of the vehicle has decreased based on the steering state of the driver.

  The consciousness decrease determination device 100 is configured around an ECU (Electronic Control Unit) 1 serving as a control unit, and includes a front detection unit 2, a vehicle speed sensor 3, a yaw rate sensor 4, and an alarm unit 5.

  The forward detection unit 2 functions as road information acquisition means for acquiring road information ahead of the vehicle. For example, it is configured by a camera that captures an image of the front of the vehicle and an image processing device. The image processing device detects a white line on the road from a captured image or captured image acquired by the camera. The front detection unit 2 outputs the detected white line information to the ECU 1. The image processing apparatus may be integrated in a road information acquisition unit 11 in the ECU 1 described later.

  The vehicle speed sensor 3 and the yaw rate sensor 4 function as vehicle information acquisition means for acquiring vehicle travel information. As the vehicle speed sensor 3, for example, a wheel speed sensor is used. As the yaw rate sensor 4, a gyro sensor or the like can be used. The outputs of these sensors are input to the ECU 1.

  The warning unit 5 is a warning unit that gives a warning to the driver of the vehicle, and operates according to a warning control signal output from the ECU 1. As this warning part 5, what gives a warning to a driver through five senses, such as a driver's hearing, vision, and touch, is used. For example, a speaker, a buzzer, a monitor of a navigation system, a display, a lamp, an LED, a handle, or a vibration device installed on a seat is used. Any one of these may be used, and a plurality of warning means may be provided.

  The ECU 1 is an electronic control unit that controls the entire apparatus of the consciousness determination apparatus 100, and mainly includes a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), for example. The circuit includes an output signal circuit and a power supply circuit. The ECU 1 may include each unit described later as separate hardware, but may be realized by software using common hardware.

  The ECU 1 includes a road information acquisition unit 11, a vehicle information acquisition unit 12, a departure risk level calculation unit 13, a departure risk level determination unit 14, a consciousness decrease determination unit 15, and an alarm control unit 16.

  The road information acquisition unit 11 grasps the width of the travel lane, the curvature, the direction of the host vehicle with respect to the travel lane, and the like based on the white line information of the travel path (travel lane) acquired by the front detection unit 2. The form which acquires these information in the front detection part 2, and transmits to the road information acquisition part 11 may be sufficient. Further, as described above, the white line recognition itself may be performed by the road information acquisition unit 11.

  The vehicle information acquisition unit 12 calculates the vehicle speed V and the yaw rate φ based on the outputs of the vehicle speed sensor 3 and the yaw rate sensor 4.

  The departure risk degree calculation unit 13 calculates a departure risk degree with respect to the travel lane of the vehicle, and functions as a departure risk degree determination unit together with a departure risk degree determination unit 14 described later. The departure risk is calculated based on at least the vehicle speed, the traveling direction with respect to the traveling lane, and the lateral position with respect to the traveling lane.

  In this way, by calculating the deviation risk with respect to the traveling lane of the vehicle based on the vehicle speed, the traveling direction with respect to the traveling lane, and the lateral position with respect to the traveling lane, the vehicle is based on the physical traveling state or behavior state of the vehicle. The objective deviation risk can be calculated. Compared to the case of calculating the deviation risk of the vehicle only by the lateral position of the vehicle, the vehicle speed and the traveling direction of the vehicle are taken into consideration, so whether the vehicle is trying to avoid an obstacle on the road It is possible to accurately identify whether the person is about to deviate due to a decrease in the consciousness of the person.

  That is, when calculating the vehicle departure risk only from the lateral position of the vehicle, the departure risk is determined to be high when the lateral position of the vehicle is at the end position of the lane. However, in the consciousness deterioration determination device according to the present embodiment, by adding the vehicle speed and the traveling direction of the vehicle to the calculation of the departure risk, the vehicle speed is slow even if the lateral position of the vehicle is at the end position of the lane. If the traveling direction is parallel to the traveling path, it is possible to appropriately determine that the degree of departure is not high.

  The departure risk is calculated as, for example, the minimum yaw rate necessary for avoiding the departure of the vehicle. This departure risk MLC can be calculated by the following equation (1).

  MLC = v · (1-cos θ) / (w / 2−y) (1)

  Here, v is the vehicle speed, θ is the yaw angle of the vehicle with respect to the white line (lane marker), w is the lane width, and y is the lateral position (lateral deviation) of the vehicle with respect to the center of the lane. As the vehicle speed v, vehicle speed data based on the output signal of the vehicle speed sensor 3 may be used. The yaw angle θ, the lane width w, and the lateral position y may all be acquired by the road information acquisition unit 11.

  As the departure risk, a value other than the minimum yaw rate necessary for avoiding the departure of the vehicle may be used as long as it is an index of the risk of departure from the lane of the vehicle.

  The departure risk determination unit 14 determines whether or not the departure risk of the vehicle is greater than or equal to a set value. As the set value serving as the threshold value for determining the departure risk, a value set in advance in the ECU 1 is used. Note that this set value may be changeable according to the vehicle speed, road conditions, and driver.

  The alarm control unit 16 controls the output of an alarm control signal to the alarm unit 5 when the driver is in a state of reduced consciousness, and functions as an alarm control unit.

  Next, the operation of the consciousness deterioration determination apparatus 100 according to the present embodiment will be described.

  FIG. 2 is a flowchart showing the operation of the consciousness degradation determination apparatus 100. A series of control processing shown in this flowchart is repeatedly executed at a cycle (for example, 100 ms) preset by the ECU 1 while the vehicle is powered on, for example.

  In the first step S1, the road information acquisition unit 11 and the vehicle information acquisition unit 12 read respective outputs from the front detection unit 2, the vehicle speed sensor 3, and the yaw rate sensor 4, and acquire vehicle information and road information. Here, the vehicle speed V and the yaw rate φ are acquired as vehicle information, and the yaw angle θ, the lane width w, the lateral position y, and the curve curvature ρ with respect to the lane are acquired as road information.

  Subsequently, in step S2, the departure risk degree calculation unit 13 calculates the above-described departure risk degree MLC. The departure risk MLC can be obtained from the vehicle speed V, the yaw angle θ, the lane width w, and the lateral position y.

  In the subsequent step S3, the departure risk determination unit 14 compares the departure risk MLC with a preset threshold value a. If the departure risk MLC is equal to or less than the threshold value a, it is determined that there is no departure risk, the process proceeds to step S6, the no-steering departure flag is turned off, and the process ends. On the other hand, if the departure risk MLC exceeds the threshold value a, it is determined that there is a departure risk, and the process proceeds to step S4 to determine the non-steering state.

  In step S4, the departure risk determination unit 14 compares the absolute value of the yaw rate φ with a preset threshold value b. If the absolute value of the yaw rate φ is greater than or equal to the threshold value b, the turning force is applied to the vehicle and it is considered that the vehicle is in the steering state. Therefore, it is determined that the vehicle is not in the non-steering state, and the process proceeds to step S6. The no-steering deviation flag is turned off and the process is terminated.

  On the other hand, when the absolute value of the yaw rate φ is lower than the threshold value b, no turning force is applied to the vehicle, and it is considered that the vehicle is in a non-steering state. Set to ON to end the process.

  The alarm control unit 16 checks the value of the no-steering deviation flag at a predetermined timing. If the value is on, the warning control unit 16 determines that the consciousness is lowered due to no-steering deviation and outputs an alarm control signal to the alarm unit 5. . By this alarm processing, the alarm unit 5 issues an alarm operation to the driver, for example, sounds or alarm sounds, displays an alarm on the monitor or display, or gives an alarm vibration to the handle or seat. As a result, the driver is expected to change from a conscious state to an awake state.

  As described above, according to the consciousness decrease determination device according to the present embodiment, since it is determined whether or not the vehicle is in the non-steering state based on the actual yaw rate, no steering is performed even in a place where there is a lot of road disturbance due to road surface unevenness or the like. The deviation state can be accurately determined.

  FIG. 3 is a graph showing an example of time change of each variable during this process. An example is shown in which the driver's consciousness is reduced and the vehicle is deviating from the lane without steering. The yaw rate is in the range of greater than -b and less than b, since the vehicle is not steered. As the vehicle deviates from the center line of the lane, the MLC increases and exceeds the threshold value a at a certain point. The no-steering deviation flag set in step S5 or S6 is switched from off to on at this time. In this way, the no-steering deviation state can be accurately determined.

  FIG. 4 is a flowchart showing another embodiment of the determination process in the apparatus of FIG. The process of this embodiment is different only in that step S12 is inserted between steps S1 and S2 of the determination process shown in FIG. That is, the process of step S11 shown in FIG. 4 is the same as the process of step S1 shown in FIG. 2, and the processes of steps S13 to S17 shown in FIG. 4 are the same as the processes of steps S2 to S6 shown in FIG. is there. For this reason, description of these common processes is omitted.

  The process of step S12 performed only by the process shown in FIG. 4 is a curve radius R (the inverse of the curve curvature ρ, and the curve curvature ρ is 0, that is, the value is ∞ on a straight road). The threshold value c is compared. When the curve radius R is c or less, that is, when the curve is a steep curve having a radius less than or equal to a predetermined threshold, the process proceeds to step S17 without performing the non-steering deviation determination process in steps S13 to S15. Set the no-steer deviation flag off. On the other hand, the process proceeds to step S13 only when the curve radius R exceeds c, that is, when the curve radius is a gentle curve or straight road having a curve radius larger than a predetermined threshold value, and the subsequent non-steer deviation determination process is performed. .

  When driving on a curve, particularly when the curve radius is small, the driver may travel on a path with a gentler radius than the travel lane due to out-in-out travel. During such out-and-out running, the change in the yaw rate becomes small, and if the processing of FIG. In the present embodiment, when the curve radius is small, the determination of the non-steering state is not performed, thereby preventing erroneous determination of the non-steering state during the out-in-out traveling.

  In addition, embodiment mentioned above demonstrated embodiment of the consciousness fall determination apparatus based on this invention, and the consciousness fall determination apparatus based on this invention is not limited to what was described in this embodiment. The consciousness decrease determination apparatus according to the present invention may be a modification of the consciousness decrease determination apparatus according to the embodiment or application to another without changing the gist of the present invention.

  For example, the processing order of steps S3 and S4 in FIG. 2 may be switched (the same applies to steps S14 and S15 in FIG. 4), and the processing in step S12 in FIG. 4 is performed after any of steps S13, S14, and S15. It may be changed. Moreover, you may acquire road information by map information, road-to-vehicle communication, etc.

DESCRIPTION OF SYMBOLS 1 ... ECU, 2 ... Front detection part, 3 ... Vehicle speed sensor, 4 ... Yaw rate sensor, 5 ... Alarm part, 11 ... Road information acquisition part, 12 ... Vehicle information acquisition part, 13 ... Deviation risk calculation part, 14 ... Deviation Risk level determination unit, 15 ... Decrease in consciousness determination unit, 16 ... Alarm control unit.

Claims (2)

In the low consciousness determination device that determines whether the driver of the vehicle is in a low consciousness state,
Road information acquisition means for acquiring road information of a road on which the vehicle is traveling;
Vehicle information acquisition means for acquiring vehicle travel information;
Deviation risk determination means for determining the risk of departure from the travel lane of the vehicle based on the acquired road information and travel information;
And a determination unit that determines that the driver is in a state of reduced consciousness when the determined degree of departure risk is greater than a preset threshold value and the detected actual yaw rate is less than a preset threshold value. A consciousness deterioration determination device characterized by 2. The consciousness deterioration determination device according to claim 1, wherein the determination unit does not determine the consciousness reduction state when the curve radius of the traveling lane is equal to or less than a preset threshold value.

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