JP2009090876A - Nap prevention device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nap prevention device capable of awaking sleepiness by preventing a driver's practice. <P>SOLUTION: When reduction of awakening degree (napping state) of the driver is detected, humidity of a periphery of the driver is reduced to make the driver in the dry eye state. Thereby, since the number of blink of the driver is increased, lengthening of the eye-closed state is not eliminated. As a result, the driver can be prevented from being practiced to napping warning and sleepiness of the driver can be effectively awaken. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dozing prevention device that prevents a driver who controls a vehicle from falling asleep.

Conventionally, as a technique for preventing a driver from falling asleep, there is known a wakefulness reduction warning device that gives a warning by giving a vibration to a driver when a decrease in the driver's wakefulness is detected (for example, Patent Document 1).
JP-A-8-268287

  However, in the prior art described in Patent Document 1, once the driver gets used to the alarm by vibration, there is a problem that it becomes difficult to exert the effect and the effect of preventing drowsiness due to vibration does not continue. May fall asleep.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a snooze prevention device capable of preventing a driver from getting used to waking up.

  A snooze prevention device according to the present invention is a snooze prevention device that prevents a driver driving a vehicle from falling asleep. The device includes a wakefulness determination unit that determines whether or not a driver's wakefulness is lowered, and a wakefulness determination. When it is determined by the means that the driver's arousal level has been reduced, humidity reduction means for reducing the humidity around the driver is provided.

  According to such a snoozing prevention device, when a decrease in the driver's arousal level (sleeping state) is detected, the humidity around the driver can be lowered. As a result, the driver is in a dry eye state and the number of blinks is increased, so that the closed eye state is not prolonged. As a result, it is possible to prevent the driver from becoming accustomed to the drowsiness alarm and effectively wake up the driver.

  The humidity reducing means is preferably a dry air ejector that blows dehumidified dry air onto the driver's face. In this way, by blowing the dehumidified dry air onto the driver's face, the driver can be effectively brought into a dry eye state.

  According to the drowsiness prevention device of the present invention, it is possible to prevent the driver from getting used to the dozing alarm and to effectively wake up the driver.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a dozing prevention apparatus according to the invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a block diagram showing a dozing prevention apparatus according to an embodiment of the present invention.

  A dozing prevention apparatus 10 shown in FIG. 1 is mounted on a vehicle and prevents a driver from falling asleep, and includes a face image capturing camera 12, a face image processing ECU 14, a dozing prevention ECU 16, and a dry air ejector 18. Yes. The face image processing ECU 14 and the dozing prevention ECU 16 are connected by a communication circuit such as a CAN (Control Area Network), for example, and can exchange data with each other. The face image processing ECU 14 and the dozing prevention ECU 16 are configured by a CPU that performs arithmetic processing, a ROM and a RAM that are storage units, an input signal circuit, an output signal circuit, a power supply circuit, and the like.

  The face image capturing camera 12 is installed on a column cover, for example, and acquires a driver's face image. The face image capturing camera 12 is, for example, a near-infrared camera, and receives the reflected light reflected from the near-infrared ray irradiated from the near-infrared projection device (not shown) on the face of the driver D, thereby causing the face of the driver D Image. For example, the face image capturing camera 12 can acquire an image of 30 frames per second.

  The face image processing ECU 14 is electrically connected to the face image capturing camera 12. The face image processing ECU 14 performs image processing on the image signal input from the face image capturing camera 12 to recognize the driver's face image. In the face image processing ECU 14, for example, features such as face contour edge extraction processing for detecting the contour of the driver's face, face orientation angle determination processing for determining the driver's face orientation angle, face components (eyes, nose, mouth), etc. Face feature point extraction processing for extracting points and eye opening degree determination processing for determining the degree of eye opening of the driver are executed.

  In the CPU of the dozing prevention ECU 16, the sleepiness estimation unit 20 and the control unit 22 are configured by executing a program stored in the storage unit.

  The drowsiness estimation unit 20 functions as an arousal level determination unit of the present invention that determines whether or not the driver's arousal level is lowered, and is in a state of reduced consciousness when the arousal level is equal to or less than a threshold value. Estimated. Based on the information from the face image processing ECU 14, the sleepiness estimation unit 20 determines whether or not the driver is in a state of reduced consciousness (sleeping state). For example, if the driver's degree of eye opening is low, it may be estimated that the driver is in a state of reduced consciousness, or based on the driver's face orientation angle, it may be estimated that the driver is in a state of reduced consciousness Good. Note that, for example, the driver's consciousness reduction state may be estimated based on other biological information of the driver. Further, a threshold for estimating that the driver is in a state of reduced consciousness is stored in the storage unit of the dozing prevention ECU 16. This threshold value can be determined by experiments or the like.

  In addition, the sleepiness estimation unit 20 counts the number of times the driver blinks based on information from the face image processing ECU 14. In addition, the sleepiness estimation unit 20 measures the driver's eye closure time based on information from the face image processing ECU 14.

  The dry air ejector 18 is driven based on a signal from the control unit 22 of the dozing prevention ECU 16 and blows dehumidified dry air onto the driver's face. The dry air ejector 18 blows dry air toward the vicinity of the driver's eyes. Instead of dry air, other gas may be blown. In short, the atmospheric humidity in the vicinity of the driver may be reduced to make the driver dry.

  The controller 22 controls the driving of the dry air ejector 18. The control unit 22 drives the dry air ejector 18 when the driver's arousal level is low. Further, when the number of blinks exceeds the reference value, the control unit 22 stops the blowing of dry air on the assumption that there is a dry air blowing effect. Moreover, the control part 22 stops the spraying of dry air noting that it had the dry air spraying effect, when eye-closing time fell below a reference value.

  Next, operation | movement of the dozing prevention apparatus 10 comprised in this way is demonstrated. FIG. 2 is a flowchart showing an operation procedure of control processing executed by the dozing prevention apparatus according to the embodiment of the present invention.

  First, a face image of the driver is photographed by the face image capturing camera 12 (S1). A signal related to the captured face image is transmitted to the face image processing ECU 14. Subsequently, the face image processing ECU 14 inputs a signal from the face image capturing camera 12 and performs image processing to recognize the driver's face image (S2). The face image processing ECU 14 performs face orientation angle determination, eye opening degree determination, and the like based on the face image. Information regarding these determination results is transmitted to the dozing prevention ECU 16.

  Next, the dozing prevention ECU 16 estimates the driver's consciousness reduction state based on the information from the face image processing ECU 14. For example, a driver's consciousness reduction state is estimated by eye opening degree determination (S3).

  Next, the dozing prevention ECU 16 determines whether or not the driver is in a state of reduced consciousness (S4). If it is determined that the driver is in a state of reduced consciousness, the process proceeds to step 5, and if it is not determined that the driver is in a state of reduced consciousness, the process is terminated.

  In step 5, dry air is sprayed. The dozing prevention ECU 16 transmits a signal to the dry air ejector 18 to blow dry air into the eyes of the driver. Next, the dozing prevention ECU 16 counts the number of blinks of the driver, and executes a blink number determination process for determining whether or not the number of blinks is equal to or greater than a reference value (S6).

  Next, the dozing prevention ECU 16 measures the driver's eye closing time, and executes eye closing time determination processing for determining whether the eye closing time is equal to or less than a reference value (S7). Next, the dozing prevention ECU 16 determines whether or not there is an effect of blowing dry air (S8). When the number of blinks is equal to or greater than the reference value, or when the eye closing time is equal to or less than the reference value, it is determined that there is an effect of blowing dry air. If it is determined that there is an effect of spraying dry air, the process proceeds to step 9, and if it is not determined that there is an effect, the processes of steps 5 to 8 are repeated. In step 9, the dozing prevention ECU 16 ends the blowing of dry air.

  In such a snooze prevention device 10, when a decrease in the driver's consciousness is detected, the air around the driver's eyes is blown to reduce the humidity around the driver, so that the driver can dry the eyes. State. As a result, the driver is in a dry eye state and the number of blinks is increased, so that the closed eye state is not prolonged. As a result, it is possible to prevent the driver from becoming accustomed to the drowsiness alarm and effectively wake up the driver.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. In the above embodiment, the humidity around the driver's eyes is reduced by blowing dry air around the driver's eyes with the dry air ejector, but the humidity around the driver is reduced by other methods. It may be lowered.

  Moreover, in the said embodiment, although a driver | operator's consciousness fall state is detected based on a driver | operator's face image, based on a driver | operator's biometric information (heart rate, blood pressure, body temperature, etc.), a driver | operator's consciousness state is detected. The state of reduced consciousness may be detected, and the state of reduced consciousness of the driver may be detected based on the operation of the driver.

It is a block block diagram which shows the dozing prevention apparatus which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the control processing performed with the dozing prevention apparatus which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Dozing prevention apparatus, 12 ... Face image pick-up camera, 14 ... Face image processing ECU, 16 ... Dozing prevention ECU, 18 ... Dry air ejector, 20 ... Drowsiness estimation part, 22 ... Control part.

Claims (2)

A snooze prevention device for preventing a driver navigating a vehicle,
Wakefulness determination means for determining whether or not the driver's wakefulness is reduced;
A drowsiness prevention apparatus comprising: a humidity reduction unit that reduces the humidity around the driver when the driver's arousal level is determined to be decreased by the arousal level determination unit.   The doze prevention device according to claim 1, wherein the humidity reducing means is a dry air ejector that blows dehumidified dry air onto the face of the driver.

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