JP6638213B2 - Vehicle safe driving promotion method and vehicle safe driving promotion device - Google Patents

Description

  The present invention relates to a method for promoting safe driving of a vehicle and a device for promoting safe driving of a vehicle. The present invention relates to a method and apparatus for promoting safe driving of a vehicle, which promotes safe driving by suppressing reliability and improving reliability.

  There has been proposed a device that determines a driver's inattentiveness (looking aside) based on a face direction and a line-of-sight direction of a driver who drives a vehicle, and warns the driver when it is determined that the driver is inattentive. (For example, see Patent Document 1).

  In this device, when the direction of the driver's face deviates from the front by a predetermined reference or more, the driver determines that the driver's face is not facing the front (forward), and the driver turns the front. It is determined whether the driver is gazing or looking aside, and warns the driver when the looking aside time exceeds a predetermined time.

  However, when the face direction angle and the line-of-sight angle are equal to or more than a predetermined angle as in this device for a predetermined time or more, an alarm is issued, that is, the action of the driver at the current time alone is determined to be inattentive (looking forward). However, it is difficult to determine whether the determined action of the driver is an inattentive action or a viewing action for checking a side mirror (a rear view mirror outside the vehicle body). .

  In particular, in the situation where the driver looks aside, the driver often repeats the forward confirmation and the inattentive due to the conflict of wanting to look at the object of concern while worrying about the front. In such a situation, it is more difficult to determine whether the driver's behavior is inattentive or visual recognition. For example, in a situation where forward confirmation and inattentiveness are repeated, or forward confirmation and visual recognition behavior are repeated, in order to reduce false alarms in visual recognition behavior, when any one of the predetermined angle and the predetermined time is increased, It is more likely that the driver will not be warned in spite of his inattentive behavior. On the other hand, if any of the predetermined angle and the predetermined time is reduced in order to reduce the unwarned alarm in the inattentive operation, the number of false alarms in which an alarm is issued regardless of the driver's action being the visual recognition action increases.

  As described above, depending on the setting of the criterion for judging the driver's inattentiveness, an increase in the number of non-alarms may not be able to warn the driver even if the driver's behavior is inattentive. The problem and an increase in false alarms cause a problem that the driver is troublesome to the alarms and the reliability of the alarms is reduced.

  As a result, if the judgment of inattentiveness ahead is made based only on the driver's actions at the current time, if the number of unwarned alarms increases, the driver will not be warned in a short term and will be able to safely drive the vehicle. If the alarm cannot be maintained and the number of false alarms increases, the reliability of the alarm for the alarm will be reduced over the long term or on a daily basis, eventually causing the driver to ignore the alarm. There is.

JP 2008-097445 A

  SUMMARY OF THE INVENTION It is an object of the present invention to reduce both unwarned and false alarms with respect to a warning about a driver's unsightly fixation in the forward direction, suppress troublesomeness of a driver's warning, improve reliability, and promote safe driving. It is an object of the present invention to provide a vehicle safe driving promotion method and a vehicle safe driving promotion device that can perform the above.

The method for promoting safe driving of a vehicle of the present invention that achieves the above object determines whether or not the behavior of the driver driving the vehicle is forward gaze, and determines that the behavior of the driver is forward gaze. In the method for promoting safe driving of a vehicle that issues an alarm when the vehicle has been driven, a step of obtaining the angle of the driver's face direction or the line of sight in the left-right direction based on the traveling direction of the vehicle, and Storing as a series, converting the time series of the angle in the past fixed period into a power spectrum, and integrating the frequency based integration of a function based on the power spectrum density in a predetermined frequency range of the converted power spectrum. Calculating a value; determining whether the calculated integral value is equal to or greater than a preset alarm issuing threshold value; If it is determined that the above issuance threshold is a method characterized in that it comprises the steps of issued the alarm. Further, the method for promoting safe driving of a vehicle of the present invention that achieves the above object determines whether or not the behavior of the driver driving the vehicle is forward gaze, and the behavior of the driver is forward gaze. In the method for promoting safe driving of a vehicle that issues an alarm when it is determined that, the step of obtaining the angle of the driver's face direction or line of sight in the left-right direction based on the traveling direction of the vehicle, and the obtained angle In a time series, converting a time series of the angle in a past fixed period into a power spectrum, and calculating a maximum value of a power spectrum density in a preset frequency range of the converted power spectrum. And determining whether the calculated maximum value is equal to or greater than a preset alarm issuance threshold, and determining that the maximum value is equal to or greater than the alarm issuance threshold. When a method which comprises the steps of: for issued the alarm.

Further, the vehicle safe driving promotion device of the present invention that achieves the above object is a determining unit that determines whether the behavior of the driver driving the vehicle is forward gaze, and the determining unit In a device for promoting safe driving of a vehicle comprising an alarm unit that issues an alarm when the action is determined to be forward gaze, the angle of the driver's face direction in the left-right direction with respect to the traveling direction of the vehicle or An angle acquisition unit that acquires an angle of a line of sight, a storage unit that stores the angles acquired by the angle acquisition unit in a time series, and a time series of the angles in a past fixed period from information stored in the storage unit. the a calculation unit that calculates an integrated value of frequency integrating the function based on the power spectral density at the predetermined frequency range of the power spectrum transformed converter which converts the power spectrum, the determination unit, The integrated value calculated by the calculating unit is configured to determine whether the integrated value is equal to or greater than a preset warning issuance threshold, and the alarm unit is determined by the determination unit that the integrated value is equal to or greater than the alarm issuing threshold. In such a case, the alarm is issued in such a case . Further, the vehicle safe driving promotion device of the present invention that achieves the above object is a determining unit that determines whether the behavior of the driver driving the vehicle is forward gaze, and the determining unit In a device for promoting safe driving of a vehicle including an alarm unit that issues an alarm when the action is determined to be forward gaze, the angle of the face direction of the driver in the left-right direction with respect to the traveling direction of the vehicle or An angle acquisition unit that acquires an angle of a line of sight, a storage unit that stores the angles acquired by the angle acquisition unit in a time series, and a time series of the angles in a past fixed period from information stored in the storage unit. A conversion unit that converts the power spectrum into a power spectrum, and a calculation unit that calculates the maximum value of the power spectrum density in a preset frequency range of the converted power spectrum, wherein the determination unit is calculated by the calculation unit. The said The value is configured to determine whether the value is equal to or greater than a preset alarm issuance threshold, and the alarm unit is configured to issue the alarm when the determination unit determines that the maximum value is equal to or greater than the alarm issuance threshold. It is characterized by having done.

  According to the vehicle safe driving promotion method and the vehicle safe driving promotion apparatus of the present invention, the detected power angle obtained by converting the angle of the face direction or the angle of the line of sight in a time series and converting the time series of the angle in the past certain period. By determining whether or not the driver's action is forward gaze, based on the information, it is possible to consider not only the current action of the driver but also the history of past actions. Therefore, it is possible to accurately determine whether the driver's action is an action caused by inattentive action or a visual recognition action.

  This can reduce both a non-warning when the driver's behavior is inattentive and a false alarm when the driver's behavior is visual recognition, thereby suppressing annoying the driver's warning. In addition, reliability can be improved, and safe driving can be promoted for the driver.

  In particular, the present invention provides that the behavior of the driver is inattentive even in a situation where the angle of the driver's face orientation or the line of sight frequently changes, that is, the forward confirmation and the inattentive behavior are repeated, and the forward confirmation and the visual recognition behavior are repeated. , Or whether it is a visual recognition action.

FIG. 1 is a configuration diagram illustrating a safe driving promotion device for a vehicle according to a first embodiment of the present invention. FIG. 2 is a configuration diagram illustrating an inside of a cab 12 as viewed in a traveling direction of the vehicle in FIG. 1. FIG. 3 (a) illustrates a situation where the driver is gazing forward, and FIG. 3 (b) illustrates a situation where the driver is gazing at the right side. FIG. 3C illustrates a situation in which the driver is gazing at the left side. FIG. 4 is map data stored in the storage unit of FIG. 1, illustrating a situation in which the driver's behavior is forward gaze. FIG. 4 is map data stored in the storage unit of FIG. 1, illustrating a situation in which the driver's behavior is forward gaze. 3 is map data stored in the storage unit of FIG. 1 and illustrates a situation in which the driver's action is a visual recognition action. It is a block diagram which specifically illustrates the safe driving promotion apparatus of FIG. This is power spectrum data converted into a power spectrum based on FIG. This is power spectrum data converted into a power spectrum based on FIG. 7 is power spectrum data converted into a power spectrum based on FIG. It is a flowchart which illustrates the safe driving promotion method of the first embodiment of the present invention. FIG. 12 is a diagram displaying the result of step S40 in FIG. 11 in chronological order. It is a flowchart which illustrates a safe driving promotion method of a vehicle of a first embodiment of the present invention more concretely. 14 is a flowchart illustrating step S110 in FIG. This is power spectrum data converted into a power spectrum based on FIG. This is power spectrum data converted into a power spectrum based on FIG. 7 is power spectrum data converted into a power spectrum based on FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 illustrate a safe driving promotion device 30 for a vehicle 10 according to a first embodiment of the present invention. Note that the alternate long and short dash line in the figure indicates a signal line.

  The safe driving promotion device 30 acquires the angle of the driver's face direction and the line of sight, determines the driver's inattentiveness based on the angle, and determines that the driver is inattentive. This is a device that issues an alarm.

  As shown in FIG. 1, the vehicle 10 has a cab (cab) 12 disposed in front of a chassis 11 and a body 13 disposed behind the chassis 11. Inside the driver's cab 12, a driver's seat 14 on which the driver rides, and operating devices such as a steering wheel 15, an accelerator pedal 16, and a shift lever 17 operated by the driver are arranged.

  As shown in FIG. 2, a windshield 20 is disposed in front of the cab 12 when the vehicle 10 is viewed in the traveling direction, and side glasses 21 and 22 are disposed on left and right side surfaces of the cab 12. I have. A meter panel (instruments) 23 is arranged below the windshield 20 and in front of the driver's seat 14, and a room mirror 24 is arranged above the windshield 20. Further, a right side mirror 25 is disposed on the right outside of the cab 12, that is, outside the side glass 21, and a left side mirror 26, a side under mirror 27, on the left outside of the cab 12, that is, outside the side glass 22. And an under mirror 28. Note that the configuration of the vehicle 10 is an example, and for example, a driver's seat 14 may be provided on the left side of the driver's cab 12, and the same applies to the arrangement of mirrors and the like.

  The safe driving promotion device 30 includes a camera 31 arranged above the meter panel 23 of the cab 12, a control device 32 arranged inside the dashboard of the cab 12 and connected to the camera 31, And an alarm device 33 arranged at the position 23.

The camera 31 captures a captured image Px in an imaging range including at least the face of the driver in the cab 12. When the camera 31 is applied to a large vehicle as in this embodiment, the movement of the driver's visual recognition action is larger and the number of times of the visual recognition action is larger than that of an ordinary passenger car. Alternatively, a camera unit including a plurality of cameras is preferable. The resolution of the camera 31 may be any resolution that allows the control device 32 to analyze the angle of the driver's face based on the captured image Px. In this embodiment, the camera 31 is configured to capture the direction of the driver's face, but may be configured to capture the direction of the driver's line of sight. However, in order to accurately capture the direction of the driver's line of sight, a camera with higher resolution is required.

  The control device (control unit) 32 includes a CPU for performing various processes, a ROM for temporarily storing a program used for performing the various processes, a RAM for reading and writing the processing results, and various interfaces. I have.

  The alarm 33 is composed of a buzzer or the like that sounds an alarm. The alarm device 33 may use a display device such as a display that displays a warning message to the driver, in addition to the configuration that sounds the alarm sound.

  The safe driving promotion device 30 analyzes the captured image Px captured by the camera 31 with the control device 32 to determine the driver's inattentiveness in the forward direction. The alarm 33 is sounded to issue a warning to the driver.

  FIG. 3 illustrates a captured image Px captured by the camera 31. This captured image Px is a moving image or a still image every 0.1 to 1 second. As shown in a captured image P <b> 0 in FIG. 3A, the driver normally gazes in the traveling direction of the vehicle 10 via the windshield 20, that is, in front while traveling. On the other hand, the driver visually recognizes the right side and the rear right side of the vehicle 10 via the right side mirror 25 as shown in a captured image P1 in FIG. Then, as shown in a captured image P2 in FIG. 3C, a left visual recognition action of visually recognizing the left side and the left rear side of the vehicle 10 via the left side mirror 26, the side under mirror 27, the under mirror 28, and the like is performed. ing. In addition, examples of the visual recognition behavior include a lower visual recognition behavior for visually recognizing the meter panel 23 and the like, and a rear visual recognition behavior for visually recognizing the rear of the vehicle 10 via the room mirror 24.

  That is, the driver maintains the safe driving by gazing at the front while performing the visual recognition action in directions other than the front as appropriate. However, when an anxious object is reflected in the scenery outside the vehicle 10, when operating an air conditioner or an audio device arranged on the dashboard, or when worried about a wristwatch or a mobile phone, When the driver turns his / her gaze on the target, the driver becomes inattentive, so-called inattentive.

  4 to 6 exemplify map data D1x in which the behavior of the driver is converted into an angle θ of the face of the driver based on the traveling direction of the vehicle 10. In the map data D1x, the current time is indicated by t. The map data D11 in FIG. 4 and the map data D12 in FIG. 5 illustrate a situation in which the driver repeatedly checks forward and looks aside because of a conflict of wanting to see an object of interest while worrying about the front. On the other hand, the map data D13 in FIG. 6 illustrates a situation where the driver has performed a visual recognition action for safe driving.

  As shown in FIGS. 4 to 6, when the angle of the face direction and the duration of the action are used as the determination criterion, for example, it can be determined that the user is not looking forward in the situation of FIG. May not be determined, or it may be determined that the driver is not looking forward in the situation of FIG. 5, but may not be determined to be the visual recognition action for safe driving in the situation of FIG.

  Therefore, in the safe driving promotion device 30 of the present invention, as shown in FIG. 7, the control device 32 includes the angle acquisition unit 34, the storage unit 35, the conversion unit 36, the calculation unit 37, the determination unit 38, and the alarm unit 39. It is comprised including. Then, in the safe driving promotion device 30, the angle acquisition unit 34 acquires the angle θ of the driver's face direction in the left-right direction based on the traveling direction of the vehicle, and stores the acquired angle θ in a time series in the storage unit 35. The conversion unit 36 converts the time series of the angle θ (t) in the past fixed period ta into the power spectrum PSDx, and the calculation unit 37 and the determination unit 38 determine the behavior of the driver based on the power spectrum PSDx. It is configured to determine whether or not the user is not looking forward.

  Note that each of the angle acquisition unit 34, the conversion unit 36, the calculation unit 37, the determination unit 38, and the alarm unit 39 is specified in advance by reading the execution program stored in the storage unit 35 into the ROM by the CPU. And a different control device.

  The angle acquisition unit 34 reads and analyzes the captured image Px captured by the camera 31 and stored in the storage unit 35, and obtains the angle θ of the driver's face direction in the left-right direction based on the traveling direction of the vehicle 10. It is a means for processing the step of acquiring and storing the angle θ in the storage unit 35.

  The storage unit 35 is configured by a storage medium such as a nonvolatile memory or a hard disk, and stores a captured image Px captured by the camera 31, a program read into the ROM of the control device 32, a result of each process in the control device 32, and the like. . Further, the storage unit 35 stores map data D1x shown in FIGS. 4 to 6 in which the angle θ of the face direction acquired by the angle acquisition unit 34 is stored in a time series.

  The conversion unit 36 reads the map data D1x stored in the storage unit 35, converts the time series of the angle θ in the past fixed period ta from the current time t into a power spectrum (or a power spectrum density function), and stores the converted data. It is means for processing the step of storing in the unit 35.

  8 to 10 show power spectrum data D2x obtained by converting the time series of the angle θ in the past fixed time ta from the current time t of the map data D1x shown in FIGS. 4 to 6. In the power spectrum data D2x, the horizontal axis represents frequency, and the vertical axis represents power spectrum density. The frequency is the reciprocal of one cycle T1 and is expressed as 1 / T1, and the power spectrum density PSD is obtained by performing an FFT analysis (fast Fourier transform) on the time series of the angle θ (t) for each elapsed time T2 in the past fixed period ta of the map data Mx. The value converted by (Analysis) is squared, and the value is averaged for the energy of frequency 1 / T1. One cycle T1 indicates one wave formed by a change in the angle θ, that is, by increasing and decreasing the angle θ. Note that the conversion unit 36 only needs to be able to convert the power spectrum data D2x from the map data D1x, and for example, may be configured by an analog circuit combining a bandpass filter and a root-mean-square circuit.

  In addition, the past fixed period ta used in the conversion unit 36 can be obtained by an experiment, a test, or learning, and can take into account the driver's behavior going back from the current time t in the past. Set to the included value. If the past fixed period ta is set to less than 1 second, the past behavior of the driver cannot be sufficiently considered, and the judgment accuracy in the judgment unit 38 decreases. Is considered excessively, and the determination accuracy is reduced. Therefore, the past fixed period ta is preferably, for example, 1 second or more and 10 seconds or less.

  The calculation unit 37 reads out the power spectrum data D2x stored in the storage unit 35, and calculates an integral value IVx as an integral value obtained by frequency-integrating each power spectrum density PSD (f) in a preset frequency range fa, This is a means for processing the step of sending the calculated integrated value IVx to the determination unit 38. The calculated integrated value IVx may be stored in the storage unit 35.

The integral value IVx calculated by the calculation unit 37 is represented by the following equation (1). Here, the frequency range fa is a range from the first frequency f1 to the second frequency f2, and a function based on the power spectrum density PSD for each unit frequency 1 / T1 in the range is g {PSD (f)}.

  Therefore, this integral value IVx is the area of the hatched portion in FIGS. 8 to 10 and is not only the behavior of the driver at the current time t but also the magnitude of the behavior of the driver during the past fixed period ta (the magnitude of the angle θ). ) And the number of actions.

  Further, the frequency range fa used in the calculation unit 37 can be obtained by an experiment, a test, or learning, and is a range including the case where the driver's behavior is inadvertent gaze, and the driver's behavior is visual recognition behavior. Is set to a range that does not include the frequency as much as possible. This frequency range fa is preferably set to a different range depending on the driver, and may be updated as a learning value while the vehicle 10 is traveling. Therefore, the first frequency f1 in this frequency range fa is preferably equal to or higher than the frequency when the behavior of the driver at the average time in the visual recognition action is the frequency, and the second frequency f2 is extremely short (0.5 (Less than second) is preferably 1 Hz or less which excludes a change in the angle θ.

  The determining unit 38 compares the integrated value IVx calculated by the calculating unit 37 with a preset alarm issuance threshold IVa, and more specifically, determines whether or not the integrated value IVx is equal to or greater than the alarm issuance threshold IVa. Then, when the integrated value IVx is determined to be equal to or greater than the warning issuance threshold IVa, the step of determining that the behavior of the driver is forward inattention is performed.

  The warning issuance threshold value IVa used by the determination unit 38 is a value that is equal to or less than the integrated value IVx when the driver's behavior is inattentive and exceeds the integrated value IVx at that time when the driver's behavior is visual recognition. Is set to The warning issuance threshold value IVa may be obtained from, for example, some power spectrum data D23 in the visual recognition behavior shown in FIG. 10 by an experiment, a test, or learning, and from the power spectrum data D23. Specifically, the average value of the integral value IV30 by the visual recognition action for safe driving, the average value of the maximum value of the power spectrum density PSD3 in the visual recognition action, and a value obtained by multiplying the average value, or a plurality of integrated values IV30 You may want to set it to the maximum value.

  The alarm unit 39 sounds the alarm 33 when the determination unit 38 determines that the integrated value IVx is equal to or greater than the alarm issuance threshold value IVa, that is, when it is determined that the driver's behavior is forward gaze. It is means for processing the step of issuing a warning to the driver.

  The control device 32 includes a timer 40, and the timer 40 counts the current time t, the elapsed time T2, and the like.

Next, the safe driving promotion method of the first embodiment will be described below as a function of the control device 32 based on the flowchart shown in FIG. It is assumed that the imaging of the captured image by the camera 31 and the storage of the captured image in the storage unit 35 are sequentially started after the energization of the electrical system of the vehicle 10 is started. The method described below is performed for each elapsed time T2 counted by the timer 40, and the elapsed time T2 is set to, for example, 0.03 seconds or more and 1 second or less.

  First, in step S10, the angle acquisition unit 34 detects the angle θ of the driver's face direction from the captured image Px stored in the storage unit 35. Note that, although the captured image Px captured by the camera 31 is temporarily stored in the storage unit 35, the angle acquisition unit 34 reads the captured image Px and detects the angle θ of the face direction. The image Px may be immediately analyzed by the angle acquisition unit 34.

  Next, in step S20, the angle θ of the face direction detected by the angle acquisition unit 34 is stored in the storage unit 35 in time series. That is, in step S20, map data D11 to D13 shown in FIGS. 4 to 6 are created in which the face direction angle θ is arranged for each elapsed time T2 counted by the timer 40.

  Next, in step S30, the conversion unit 36 converts the time series of the angle θ from the past time (t-ta) to the current time t into power spectrum data D2x with reference to the map data D1x. That is, in this step S30, the power spectrum data D21 to D23 shown in FIGS. 8 to 10 in which the magnitude and the cycle of the angle θ are converted as the power value per unit frequency are created.

  Next, in step S40, the calculation unit 37 refers to the power spectrum data D2x and calculates the function g {PSD (f)} based on the power spectrum density PSD in the frequency range fa using the above equation (1). An integrated value IVx, which is an integrated value obtained by frequency integration, is calculated. Note that the integrated value IVx calculated in step S40 is sent to the determination unit 38. Note that the integrated value IVx may be stored in the storage unit 35.

  Next, in step S50, the determination unit 38 reads the integrated value IVx, and determines whether or not the integrated value IVx is equal to or greater than a preset warning issuance threshold IVa. In step S40, when the integrated value IVx is equal to or greater than the warning issuance threshold IVa, it is determined that the driver's action is forward gaze and the process proceeds to step S60. On the other hand, when the integrated value IVx is less than the alarm issuance threshold IVa, the driving is performed. It is determined that the person's behavior is not inadvertent gaze, that is, safe driving can be maintained, and the process returns to the start.

  Next, in step S60, the alarm unit 39 sounds the alarm 33 to issue an alarm to the driver, and returns to the start. Thus, the above-described steps S10 to S60 are repeated for each elapsed time T2.

  FIG. 12 shows the integrated value IVx calculated in step S40 in the respective situations of FIGS. 4 to 6 in time series. In the situation IV10 shown in FIG. 4, at the time t1, the integrated value IV10 becomes equal to or more than the warning issuance threshold IVa, and a warning is issued. In the situation IV20 shown in FIG. 5, at the time t2, the integrated value IV20 is equal to or more than the warning issuance threshold IVa. Then an alarm is issued. On the other hand, in IV30 showing the situation of FIG. 6, no alarm is issued because the integrated value IV30 does not exceed the alarm issuance threshold IVa in any time zone.

  In this way, the map data D1x in which the detected face orientation angles θ are arranged in time series is converted into power spectrum data D2x, and a function g ｛PSD (based on a power spectrum density PSDθ in a preset frequency range fa) is used. f) By comparing the integrated value IVx obtained by frequency-integrating と with the warning issuance threshold value IVa to determine the driver's inattentiveness ahead, the determination is not made only by the driver's action at the current time t. Since it is possible to consider the history of the action (magnitude of the angle θ) and the number of times of the action retroactive for a certain period of time ta from the current time t to the past, whether the action of the driver is an action caused by inattentive behavior Thus, it can be accurately determined whether the action is caused by the visual recognition action.

  This can reduce both a non-warning when the driver's behavior is forward gaze and a false alarm when the driver's behavior is visual recognition. It is possible to suppress and improve the reliability, and to promote safe driving for the driver.

  In particular, as shown in FIGS. 4 and 5, the angle θ of the driver's face direction changes frequently, that is, the forward confirmation and the inattentiveness are repeated, and as shown in FIG. 6, the forward confirmation and the visual recognition behavior are repeated. Even in such a situation, it is possible to accurately determine whether the driver's behavior is inattentive or visual recognition.

  Further, as shown in FIG. 12, when it is determined from the past driver's actions that the driver is not looking forward, such as looking aside, the alarm 33 continues to sound even when the driver is facing forward and issues a warning to the driver. By continuing to do so, it is also possible to reduce the trouble of the driver with respect to the alarm.

  For example, in the related art, there is a problem that the warning is canceled when the driver turns forward. That is, in the case of the driver's action as shown in FIGS. 4 and 5, the issuance and release of the alarm are repeated, and the alarm 33 is repeatedly sounded and stopped. There is a problem that increases. However, in this safe driving promotion device 30, it is determined that a series of actions of repeating forward confirmation and inattentiveness from the conflict of wanting to look at an object of concern as forward inattentiveness while continuing to be warned while being concerned about the front. Thus, the trouble of the driver can be reduced, so that these problems of the prior art can be solved.

  Further, by using the power spectrum to determine whether or not the driver's behavior is forward gaze, it is determined whether the driver's face direction is tilted to the right or left. The behavior of the driver can be determined without making any distinction.

  In the vehicle 10 of the embodiment, since the driver's seat 14 is disposed on the right side of the vehicle 10, even in the viewing behavior for safe driving, the face orientation angle θ differs between the right viewing behavior and the left viewing behavior, The angle of the face direction at the time of the left-viewing action is larger than that of the right-viewing action. Here, it is assumed that the case where the driver's face is inclined to the right is positive, and the case where the driver is inclined to the left is negative. In the first embodiment, the angle θ is converted into a power spectrum, that is, the value obtained by the FFT analysis is squared, and all the converted values are positive. Therefore, the power spectrum density PSDθ is based on the magnitude of the angle θ, the cycle of the action and the number of actions, and can be determined independently of left and right.

  In the above-described safe driving promotion method, a step of determining whether or not the calculated integrated value IVx is equal to or less than an alarm release threshold IVb set to a value smaller than the alarm issuance threshold IVa; If it is determined that the following, it is desirable to include a step of determining that the driver's action is not inadvertent gaze and canceling the warning.

  Specifically, when the integrated value IVx is equal to or greater than the alarm issuance threshold IVa when the alarm is released, that is, when it is determined that the driver's behavior is forward gaze, a warning is issued, while the alarm is issued. If it is determined that the integrated value IVx is equal to or less than the alarm release threshold value IVb, that is, if it is determined that the driver's action is not forward gaze, the alarm is released.

If the alarm release threshold IVb is set to zero, the alarm will be released when the driver is completely gazing at the front, but if set to a non-zero value, the alarm will not be released easily. Could be. Therefore, the alarm release threshold value IVb is set to a value at which the alarm is released when the driver's inattentiveness in the front is eliminated and the trouble of the driver is eliminated. For example, it is preferably set to a value near zero.

  As shown in FIG. 12, when it is determined that the alarm is to be issued and released only by the alarm issuance threshold IVa, in the situation shown in FIG. 4, the alarm is issued again at time t4 immediately after the alarm is released at time t3. I will. However, by using the alarm release threshold value IVb set to a value smaller than the alarm issuance threshold value IVa, it is possible to continue to sound the alarm from time t3 to time t4 even in the situation shown in FIG.

  Furthermore, when it is determined whether or not the driver's behavior is forward gaze, separately for issuance and release, when performing the release determination, instead of the time series of the past fixed period ta, the determination is made. It is preferable to use a past fixed period tb set to a time different from the past fixed period ta. The past fixed periods ta and tb may be obtained by experiments, tests, or learning, and may be set to different times for each vehicle 10 or each driver.

  In addition, when it is determined whether the driver's behavior is forward gaze or not by issuing a command and canceling the command, when performing the canceling determination, instead of using the issuing frequency range fa, It is preferable to use a frequency range fb (a range between a frequency f3 and a frequency f4) that is different from the frequency range fa. The frequency ranges fa and fb may be obtained by experiments, tests, or learning, and may be set to different ranges for each vehicle 10 or each driver.

  Next, a safe driving promotion method in which the thresholds are different for the issuance and the cancellation will be described below as the function of the control device 32 based on the flowcharts shown in FIGS.

  As shown in FIG. 13, in step S100, the timer 40 adds the elapsed time T2 to the current time t. Next, after performing steps S10 to S30 described above, a determination is made in step S110 shown in FIG. Here, in step S30, the past fixed period ta of the issuing time series and the past fixed period tb of the releasing time series are set to the same value, but preferably different values as described above. In that case, the step of converting the process of step S30 based on the past fixed period ta and the step of converting based on the past fixed period tb are performed.

  Next, in step S120, the warning unit 39 determines whether or not the warning issuance flag has been raised in the determination in step S110. It should be noted that the case where the alarm issuance flag is set is indicated by flg1 = 1, and the case where the alarm release flag is set is indicated by flg1 = 0. If it is determined in this step S120 that the alarm issuance flag has been raised, the process proceeds to step S130. If it is determined that the alarm release flag has been raised, the process proceeds to step S140.

  Next, in step S130, the alarm unit 39 sounds the alarm 33 to issue an alarm to the driver, and the process proceeds to step S150. On the other hand, in step S140, the alarm unit 39 stops the alarm 33 to release the alarm, and proceeds to step S150.

  Next, in step S150, the control device 32 determines that the vehicle 10 has stopped, and if it determines that the vehicle 10 has not stopped, returns to the start and repeats steps S100 to S150. On the other hand, if it is determined that the vehicle 10 is stopped, the process proceeds to step S160, where the current time t counted by the timer 40 is reset and the process ends.

As shown in FIG. 14, in step S200, the calculation unit 37 determines whether or not an alarm issuance flag is set. If the alarm release flag is set in step S200, the process proceeds to step S210.

  Next, in step S210, the calculation unit 37 refers to the power spectrum data D2x and calculates the function g {PSD (f)} based on the power spectrum density PSD in the frequency range fa using the above equation (1). An integrated value IVx, which is an integrated value obtained by frequency integration, is calculated. Note that the integral value IVx calculated in step S210 is sent to the determination unit 38.

  Next, in step S220, the determination unit 38 reads the integrated value IVx, and determines whether or not the integrated value IVx is equal to or greater than a preset warning issuance threshold IVa. If the integrated value IVx is equal to or greater than the warning issuance threshold value IVa in step S220, it is determined that the driver is not looking ahead, and the process proceeds to step S230. In step S230, a warning issuance flag is set and the process proceeds to step S120. On the other hand, when the integrated value IVx is less than the warning issuance threshold IVa, the determination in step S200 is maintained, that is, the state in which the alarm release flag is set is maintained, and the process proceeds to step S120.

  In step S200, if the right warning issuance flag is on, the process proceeds to step S240. Next, in step S240, the calculation unit 37 refers to the power spectrum data D2x and uses the above equation (1) to calculate a function g ｛PSD (f based on the power spectrum density PSD in the release frequency range fb. ) Calculate an integral value IVx which is an integral value obtained by frequency-integrating｝.

  Next, in step S250, the determination unit 38 determines whether or not the integrated value IVx is equal to or less than a preset alarm release threshold IVb. If the integrated value IVx is equal to or less than the alarm release threshold IVb in this step S250, it is determined that the driver is not in gazing forward, that is, maintaining safe driving, and the process proceeds to step S260. In step S260, the alarm release flag is set. Then, go to step S120. On the other hand, if the integrated value IVx is greater than the alarm release threshold IVb, the determination in step S200 is maintained, that is, the state in which the alarm issuance flag is set is maintained, and the process proceeds to step S120.

  As described above, according to the above-described safe driving promotion method, when the behavior of the driver is returned from an inattentive look-ahead or the like to a behavior based on safe driving, the warning is cancelled. It is possible to reduce the trouble of the driver for the alarm. Further, by setting the alarm issuance threshold value IVa and the alarm release threshold value IVb to different values, and setting the alarm release threshold value IVb to be less than the alarm issuance threshold value IVa, the timing for sounding the alarm can be further optimized, so that the operation can be more efficiently performed. In addition to suppressing the trouble of the driver for the warning, when the driver does not look forward, the warning can make the driver aware of safe driving.

  Next, a safe driving promotion device 30 for the vehicle 10 according to a second embodiment of the present invention will be described. In the safe driving promotion device 30 of the second embodiment, a predetermined frequency range fa of the power spectrum converted by the conversion unit 36 is used instead of the calculation unit 37 of the first embodiment calculating the integrated value IVx. And the determination unit 38 determines whether the maximum value PSD_max calculated by the calculation unit 37 is greater than or equal to a preset warning issuance threshold PSDa. Configuration.

  FIGS. 15 to 17 show power spectrum data D2x obtained by converting a time series of the angle θ in the past fixed time ta from the current time t of the map data D1x shown in FIGS. 4 to 6 into a power spectrum.

The warning issuance threshold PSDa is a maximum value PSD_m when the driver's behavior is inattentive.
ax or less, and in the case of the visual recognition action, is set to a value exceeding the maximum value PSD_max at that time. The warning issuance threshold PSDa may be obtained from, for example, some power spectrum data D23 in the visual recognition behavior shown in FIG. 17 by an experiment, a test, or learning, and from the power spectrum data D23. Specifically, it is preferable to set the average value of the maximum values by the visual recognition action for safe driving, or the maximum value among a plurality of maximum values.

  In the safe driving promotion method according to the second embodiment, the integrated values of the steps processed by the calculation unit 37 and the steps processed by the determination unit 38 of the flowcharts shown in FIGS. 11 and 14 are set to the maximum value PSD_max. It can be replaced. For example, step S40 in FIG. 11 is a step for calculating the maximum value PSD_max, and step S50 is a step for determining whether or not the maximum value PSD_max is equal to or greater than the alarm issuing threshold PSDa. Further, each of steps S210 and S240 in FIG. 14 is a step of calculating the maximum value PSD_max, step S220 is a step of determining whether or not the maximum value PSD_max is equal to or greater than the alarm issuing threshold PSDa, and step S240 is a maximum value. This is a step of determining whether or not PSD_max is equal to or smaller than the alarm release threshold PSDb.

  As described above, according to the above-described safe driving promotion method, as in the first embodiment, not only the behavior of the driver at the current time t but also the behavior of the driver during the past fixed period ta is considered, and the driver is not watched ahead. To reduce both the unwarning warning and the false warning of the warning for the driver's inattention in the forward direction, suppress the trouble of the driver's warning, improve the reliability, and promote safe driving. Can be.

  The method using the integral value IVx of the first embodiment can sound an appropriate alarm when forward confirmation and inattentiveness are repeated at frequencies having dispersion (variation), while the second embodiment uses the integrated value IVx. The method using the maximum value PSD_max can sound an appropriate alarm when forward confirmation and inattentiveness are repeated at a constant frequency. Then, you may make it use the said 1st embodiment and the 2nd embodiment properly according to a situation.

  In the above embodiment, the vehicle 10 is described as an example of a truck that is a large vehicle. However, the present invention is not limited to this, and can be applied to a bus or a normal passenger car that is a shared vehicle. However, in particular, the present invention is suitable for a large vehicle having a wide vehicle width and no margin for lane departure and a high frequency of visual recognition actions because the driver wants to run stably at a constant speed as compared with an ordinary passenger vehicle.

  Further, in the above embodiment, the configuration in which the determination is performed based on the angle of the driver's face is described as an example, but the present invention is not limited to this. For example, the configuration may be such that the determination is made based on the angle of the driver's line of sight. In addition, the configuration in which the angle of the driver's face direction and the line of sight of the driver is imaged by the camera 31 has been described as an example, but it is sufficient that the angles can be acquired. For example, an ultrasonic sensor or a human sensor May be used.

  Further, in the above embodiment, the angle of the driver's face direction is obtained in the left-right direction, but the vertical direction may be considered. In that case, the calculation becomes complicated, but the determination accuracy can be further improved.

  In addition, in the flowchart of the above embodiment, the order of the steps may be changed as long as the order of the steps is not hindered in the processing. For example, the flag determination in step S200 may be performed after calculating the integral value.

Reference Signs List 10 vehicle 30 safe driving promotion device 31 camera 32 control device 33 alarm device 34 angle acquisition unit 35 storage unit 36 conversion unit 37 calculation unit 38 determination unit 39 alarm unit

Claims (6)

In the method for promoting safe driving of a vehicle, which determines whether or not the behavior of the driver driving the vehicle is forward gaze, and issues an alarm when it is determined that the behavior of the driver is forward gaze,
Step of acquiring the angle of the driver's face direction or line of sight in the left-right direction based on the traveling direction of the vehicle,
Storing the obtained angle in time series;
Converting a time series of the angle into a power spectrum in a past fixed period,
Calculating a frequency-integrated integrated value of a function based on the power spectrum density in a preset frequency range of the converted power spectrum;
Determining whether the calculated integrated value is equal to or greater than a preset warning issuance threshold,
Issuing the alarm when the integrated value is determined to be equal to or greater than the alarm issuance threshold. In the method for promoting safe driving of a vehicle, which determines whether or not the behavior of the driver driving the vehicle is forward gaze, and issues an alarm when it is determined that the behavior of the driver is forward gaze,
Step of acquiring the angle of the driver's face direction or line of sight in the left-right direction based on the traveling direction of the vehicle,
Storing the obtained angle in time series;
Converting a time series of the angle into a power spectrum in a past fixed period,
Calculating the maximum value of the power spectrum density in a preset frequency range of the converted power spectrum,
Determining whether the calculated maximum value is equal to or greater than a preset warning issuance threshold,
Issuing the alarm when the maximum value is determined to be equal to or greater than the alarm issuance threshold. If the method includes a step of calculating an integrated value obtained by frequency-integrating a function based on the power spectrum density in a preset frequency range of the converted power spectrum,
Determining whether the calculated integrated value is equal to or less than an alarm release threshold set to a value smaller than the alarm issuance threshold,
When the integrated value is determined to be equal to or less than the alarm cancellation threshold, it is determined that the behavior of the driver is not forward gaze, canceling the alarm,
When including a step of calculating the maximum value of the power spectrum density in a preset frequency range of the converted power spectrum,
A step of determining whether the calculated maximum value is equal to or less than an alarm release threshold set to a value smaller than the alarm issuance threshold,
3. The vehicle safety according to claim 1, further comprising: when the maximum value is determined to be equal to or less than the alarm release threshold, determining that the action of the driver is not forward gaze, and releasing the alarm. Driving promotion method. A determining unit that determines whether the behavior of the driver driving the vehicle is forward gaze, and an alarm unit that issues an alarm when the determination unit determines that the driver's behavior is forward gaze. In a device for promoting safe driving of a vehicle having
An angle acquisition unit that acquires the angle of the driver's face direction or line of sight in the left-right direction based on the traveling direction of the vehicle, and a storage unit that stores the angles acquired by the angle acquisition unit in time series. From the information stored in the storage unit, a conversion unit that converts the time series of the angle into a power spectrum in a fixed period in the past, and a function based on a power spectrum density in a preset frequency range of the converted power spectrum. And a calculation unit for calculating an integrated value obtained by frequency integration of
The determination unit, a configuration to determine whether the integrated value calculated by the calculation unit is equal to or more than a preset warning issuance threshold,
The device for promoting safe driving of a vehicle, wherein the warning unit is configured to issue the alarm when the determination unit determines that the integrated value is equal to or greater than the alarm issuance threshold. A determination unit that determines whether the behavior of the driver driving the vehicle is forward gaze, and an alarm unit that issues an alarm when the determination unit determines that the behavior of the driver is forward gaze. In a device for promoting safe driving of a vehicle having
An angle acquisition unit that acquires the angle of the driver's face direction or line of sight in the left-right direction based on the traveling direction of the vehicle, and a storage unit that stores the angles acquired by the angle acquisition unit in time series. From the information stored in the storage unit, a conversion unit that converts the time series of the angle into a power spectrum in a past fixed period, and the maximum value of the power spectrum density in a preset frequency range of the converted power spectrum. A calculating unit for calculating,
The determination unit, the configuration to determine whether the maximum value calculated by the calculation unit is equal to or more than a preset warning issuance threshold,
The safe driving promotion device for a vehicle, wherein the warning unit is configured to issue the warning when the determination unit determines that the maximum value is equal to or greater than the warning issuing threshold. When a calculating unit that calculates an integrated value obtained by frequency-integrating a function based on the power spectrum density in a preset frequency range of the converted power spectrum,
The determination unit, a configuration to determine whether the calculated integrated value is equal to or less than an alarm release threshold set to a value smaller than the alarm issuance threshold,
The alarm unit, when the integration value is determined to be equal to or smaller than the warning termination threshold, it is determined that the behavior of the driver is not a forward non gaze, a configuration for canceling the alarm,
When comprising a calculating unit that calculates the maximum value of the power spectrum density in a preset frequency range of the converted power spectrum,
The determination unit, the configuration to determine whether the calculated maximum value is equal to or less than the alarm release threshold set to a value smaller than the alarm issuance threshold,
Wherein the alarm unit, when the maximum value is determined to or less than the warning termination threshold, it is determined that the behavior of the driver is not a forward non gaze, to claim 4 or 5 was configured to release the alarm Vehicle driving safety promotion device.