JP2010006178A - Driving fatigue decision device - Google Patents

Abstract

A driving fatigue determination device capable of easily determining driver fatigue is provided.
According to a driving fatigue determination device, a preference deceleration G _ave is calculated as statistical data relating to a brake operation timing according to deceleration of a preceding vehicle under a follow-up running. Further, an expected deceleration _Gnow is calculated as current data regarding the current brake operation timing. Then, the driver's fatigue is determined based on the difference between the calculated preference deceleration G _ave and the expected deceleration _now . That is, the driver's fatigue can be easily determined by using the brake operation timing under a specific state of follow-up running as a reference.
[Selection] Figure 6

Description

  The present invention relates to a driving fatigue determination device for determining driver fatigue in a host vehicle such as an automobile.

As a conventional driving fatigue determination device, for example, a device described in Patent Document 1 is known. This driving fatigue determination device determines the frequency of the driving operation frequency measurement unit that measures the operation frequency of the driving operation (steering, foot brake, etc.) of the driver, and the frequency of the driver's environment adjustment operation (adjustment operation of the air conditioner, etc.). Environment measurement operation frequency measurement unit to measure, physical condition adjustment operation frequency measurement unit to measure the frequency of driver's physical condition adjustment operation (driver yawning and sneezing, etc.), and abnormal behavior of the vehicle (vehicle meandering etc.) The vehicle abnormal behavior frequency measuring unit that measures the frequency, and a fatigue level estimating unit that estimates the driver's fatigue level based on the frequency measured by each measuring unit.
Japanese Patent Laid-Open No. 6-144071

  Here, in the above-described driving fatigue determination device, as described above, fatigue is determined using the steering and foot brake operation frequency, the driver's physical condition, the vehicle behavior, and the like. That is, when determining the driver's fatigue, many reference elements are used, and these reference elements are intricately related to each other. Therefore, in recent driving fatigue determination devices, it is desired to easily determine driver fatigue.

  Then, this invention makes it a subject to provide the driving fatigue determination apparatus which can determine a driver | operator's fatigue easily.

  In order to solve the above-mentioned problems, the present inventors have conducted extensive studies and, as a result, usually monitor and warn that the vehicle is traveling following (for example, the distance between the vehicle and the preceding vehicle is kept constant). In the state), in order to maintain the inter-vehicle distance or inter-vehicle time with the preceding vehicle, the knowledge that the driver of the own vehicle (hereinafter simply referred to as “driver”) performs a braking operation according to the deceleration of the preceding vehicle was obtained. . In view of this, the inventors have found that the driver's fatigue state can be estimated by grasping the variation in the data related to the brake operation timing of the driver, and have come to the present invention.

  That is, the driving fatigue determination device according to the present invention is a driving fatigue determination device for determining the fatigue of the driver of the host vehicle, and monitors that the vehicle is traveling while maintaining a distance between the preceding vehicle and the preceding vehicle. A running control means, a statistical data obtaining means for obtaining statistical data relating to a driver's brake operation timing according to the deceleration of the preceding vehicle in a state in which the own vehicle is following, and the traveling control means that the own vehicle is In a state where the inter-vehicle distance is maintained, current data acquisition means for acquiring current data relating to the driver's current brake operation timing, statistical data acquired by the statistical data acquisition means, current data acquired by the current data acquisition means, And a fatigue determination means for determining the driver's fatigue based on the deviation.

  In this driving fatigue determination device, statistical data relating to the brake operation timing according to the deceleration of the preceding vehicle is acquired under the following traveling. And a driver | operator's fatigue is determined based on the deviation (variation) of the acquired statistical data and the present data regarding the present brake operation timing. That is, the driver's fatigue can be easily determined by using the brake operation timing under a specific state of follow-up running as a reference. Further, since the driver's fatigue is determined based on the statistical data of the driver's confidence as described above, the driver's own characteristics such as operation characteristics are taken into consideration for the determination. Therefore, according to the present invention, it is possible to easily determine the driver's fatigue while taking into account the driver-specific characteristics.

  Here, it is preferable that the statistical data acquisition unit estimates the deceleration of the host vehicle at the time of the brake operation when turning from off to on, and acquires this deceleration statistics as statistical data. In this case, the driver-specific characteristics are further taken into consideration, and the above effect of easily determining the driver's fatigue is preferably exhibited.

  At this time, the statistical data acquisition means calculates the inter-vehicle time based on the relative speed of the host vehicle with respect to the preceding vehicle and the inter-vehicle distance at the time of the brake operation timing from on to off, and uses the inter-vehicle time statistics as the allowable inter-vehicle time. It is preferable to estimate the deceleration based on the relative speed of the host vehicle with respect to the preceding vehicle, the inter-vehicle distance, and the allowable inter-vehicle time at the time of the brake operation timing that is determined from off to on. In this case, the characteristics unique to the driver are further considered, and the above-described effect of easily determining the driver's fatigue is more suitably exhibited.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to determine a driver | operator's fatigue easily, considering a driver | operator's peculiar characteristic.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a schematic configuration diagram showing a driving fatigue determination device according to an embodiment of the present invention. The driving fatigue determination device of the present embodiment is for determining the fatigue of the driver of the host vehicle under the following traveling. As shown in FIG. 1, the driving fatigue determination device 1 is mounted on a host vehicle 10 and includes an ECU 2. Note that the following traveling is intended to perform a control that monitors that the distance between the preceding vehicle and the preceding vehicle is maintained and notifies the driver when the distance between the vehicles is jammed to assist the driver's accelerator operation. is doing.

  A vehicle speed sensor 3, a millimeter wave radar 4, and a brake switch 5 are connected to the ECU 2. The vehicle speed sensor 3 is for detecting the vehicle speed of the host vehicle 10. The millimeter wave radar 4 is for detecting preceding vehicle information regarding the preceding vehicle. Here, the millimeter wave radar 4 detects the inter-vehicle distance between the host vehicle 10 and the preceding vehicle, the relative speed of the host vehicle 10 with respect to the preceding vehicle, and the vehicle speed of the preceding vehicle as preceding vehicle information. The brake switch 5 detects on / off of the operation state (braking state) of the brake pedal.

  The ECU 2 includes, for example, a CPU, a ROM, a RAM, and the like. The ECU 2 executes inter-vehicle distance monitoring control between the host vehicle 10 and the preceding vehicle so as to follow the preceding vehicle. In addition, the ECU 2 detects the driver's fatigue based on the difference between the statistical data regarding the driver's brake operation timing according to the deceleration of the preceding vehicle and the current data regarding the driver's current brake operation timing under the following traveling. (Details will be described later).

  FIG. 2 is a diagram illustrating an example of the host vehicle and the preceding vehicle in the follow-up running state. In the figure, it is assumed that the host vehicle 10 and the preceding vehicle 50 travel in the traveling direction A, the horizontal axis indicates the position of each vehicle 10, 50 (here, the position on the earth fixed axis), and the vertical axis indicates time. Show. Here, the deceleration during braking of the host vehicle 10 is assumed to be constant.

  As shown in FIG. 2, in the driving fatigue determination device 1, the driver's fatigue is determined (fatigue determination) by executing the following processing in the ECU 2 during the following traveling state.

[Follow-up running judgment]
First, it is determined whether or not the host vehicle 10 is in a follow-up running state. Specifically, the vehicle speed of the host vehicle 10, the preceding vehicle information, and the operation state of the brake pedal detected by the vehicle speed sensor 3, the millimeter wave radar 4 and the brake switch 5 are input as input signals (FIG. 3). S1). Then, based on the input signal, it is determined whether or not the host vehicle 10 is in the following traveling state (S2). Here, the vehicle speed V _m of the host vehicle 10, the vehicle speed V _f of the preceding vehicle 50, the relative speed, and the inter-vehicle time T obtained by dividing the inter-vehicle distance S by the vehicle speed V _m of the host vehicle 10 are within predetermined values. Judgment by whether or not.

  In the case of Yes in S2, the count k indicating the duration of the follow-up running state is incremented as being in the follow-up running state (S3). Then, it is determined whether or not the count k is a predetermined value or more (S4). In the case of Yes in this S4, it transfers to below-mentioned S7 noting that fatigue determination is permitted. In the case of No in S4, the process proceeds to S6, which will be described later, to prohibit fatigue determination.

On the other hand, in the case of No in S2, the count k is reset because it is not in the follow-up running state (S5). Then, considering the case where the process of S15 described later is not executed for some reason, the stored inter-vehicle time maximum value _Tmax is updated to the initial value (S6). Thereafter, the process proceeds to S28 described later.

[Calculation and storage of allowable inter-vehicle time]
Next, an allowable inter-vehicle time T _ave that is an allowable inter-vehicle time T that the driver can tolerate is calculated and stored as a characteristic unique to the driver. Specifically, it is determined whether the current brake pedal operation state of the vehicle 10 (that is, the current count k) is on or off (S7 in FIG. 4). If the operation state of the brake pedal is on, it calculates the current inter-vehicle time T _now by dividing the following distance S with the vehicle speed V _m of the vehicle 10 (S8). If this inter-vehicle time _Tnow is larger than the stored inter-vehicle time maximum value _Tmax , the inter-vehicle time maximum value _Tmax is replaced with the inter-vehicle time _Tnow (S9, S10).

  On the other hand, when the operation state of the brake pedal is off, it is determined whether or not the operation state of the brake pedal at the previous time (that is, the previous count k-1) is on (S11). Thereby, it is determined whether or not it is a brake operation timing to be turned off from on.

In the case of Yes in S11 (for example, in the state P1 in FIG. 2), it is determined whether or not the stored inter-vehicle time maximum value _Tmax satisfies a predetermined condition (S12). Here, inter-vehicle time the maximum value T _max is within a predetermined value, and determines the difference between the permissible inter-vehicle time stored T _ave and following time maximum value T _max is whether within a predetermined value.

In the case of Yes in S12, the storage value T (n), which is a function value, is updated with the current maximum inter-vehicle time value _Tmax as the latest value (S13). Then, by applying the moving average method to the stored value T (n), the allowable inter-vehicle time T _ave is calculated and stored (S14).

In the case of No in S11 and S12 and after the process of S14, the inter-vehicle time maximum value _Tmax is updated to the initial value (S15). And it transfers to the process of below-mentioned S28.

[Calculation of preference deceleration]
Next, as a characteristic unique to the driver, a preference deceleration (statistical data) G _ave that is a deceleration corresponding to the deceleration of the preceding vehicle 50 and is desired by the driver is calculated and stored. Specifically, it is determined whether or not the current operation state of the brake pedal is on and the previous operation state of the brake pedal is off (for example, in the state P2 in FIG. 2) (S16 in FIG. 5). ). That is, it is determined whether or not it is a brake operation timing that is turned on from off.

If Yes in S16, an expected deceleration (current data) _Gnow , which is a deceleration due to the current brake operation, is calculated and estimated (S17). Here, as shown in the following equation (1), the expected deceleration _Gnow is estimated based on the relative speed _{Vm of} the host vehicle 10, the inter-vehicle distance S, and the allowable inter-vehicle time _Tave . Then, it is determined whether or not the estimated predicted deceleration _Gnow satisfies a predetermined condition (S18). Here, it is determined whether or not the difference between the stored preference deceleration G _ave and the expected deceleration G _now is within a predetermined value.
G _x = (− v) × (−v) / (S−V _f × T _ave ) / 2 (1)
Where v: relative speed,
S: Distance between vehicles V _f : Vehicle speed of preceding vehicle 50

In the case of Yes in S18, the storage value G (n), which is a function value, is updated with the current expected deceleration _Gnow as the latest value (S19). Then, by applying the moving average method to the stored value G (n), the preference deceleration G _ave is calculated and stored (S20), and the process proceeds to S23 described later.

[Fatigue judgment]
Next, the driver's fatigue is determined. Specifically, in the case of No in S18, a divergence comparison between the expected deceleration _Gnow and the preference deceleration _Gave is performed. Here, with respect to preference deceleration _{G ave,} expected deceleration _{G now} determines whether the deviation than a predetermined value (S21 in FIG. 6).

In the case of Yes in S21, the current driver fatigue state _Jnow is turned on (that is, _Jnow = 1) (S22). On the other hand, in the case of No in S21, the process proceeds to the subsequent process as it is. Then, the driver fatigue state S (n), which is a function value, is updated with the current driver fatigue state _Jnow as the latest state (S23).

  Here, it is determined whether or not the number of ONs in the driver fatigue state J (n) is larger than a predetermined number for detecting the fatigue state (S24). In the case of Yes in S24, the driver determines that the driver is “fatigue” (S25). Thereafter, based on the determination result, for example, the fatigue reduction means is controlled to reduce the driver's fatigue, or the alerting means is controlled to alert the driver.

  In the case of No in S24, it is determined whether the number of ONs in the driver fatigue state S (n) is smaller than a predetermined number for detecting the normal state (S26). In the case of Yes in S26, the driver determines that “the vehicle is in a normal state” (S27). On the other hand, in the case of No in S26, the process ends as it is. Thereafter, the process returns to S1.

On the other hand, after S6 and S15, and in the case of No in S16, the current driver fatigue state _Jnow is turned off ( _Jnow = 0) for fatigue determination at the next count (S28). Thereafter, the process ends, and the process returns to S1.

In the above, the ECU 2 that executes the inter-vehicle distance monitoring control so as to follow the vehicle constitutes a travel control means. The ECU 2 that calculates the preference deceleration G _ave constitutes statistical data acquisition means. The current data ECU 2 that calculates the expected deceleration G _now constitutes current data acquisition means. ECU2 which judges a driver | operator's fatigue comprises a fatigue determination means.

As described above, according to the present embodiment, the preference deceleration G _ave relating to the brake operation timing according to the deceleration of the preceding vehicle 50 is acquired as normal data under the following traveling. In addition, the expected deceleration G _now regarding the current brake operation timing is acquired as the latest data. Then, the driver's fatigue is determined based on the difference between the acquired preference deceleration G _ave and the expected deceleration G _now .

  That is, according to the driving fatigue determination device 1 of the present embodiment, the driver's fatigue is determined simply and objectively by using the brake operation timing under a specific state of follow-up traveling as a reference. Normally, when the preceding vehicle 50 is speeded down (state P3 in FIG. 2) in a state in which the host vehicle 10 is following, the driver of the host vehicle 10 performs a brake operation according to the speed down. The vehicle is braked (state P2 in FIG. 2), and the inter-vehicle distance S or inter-vehicle time T with the preceding vehicle 50 is maintained. Therefore, it is because the fatigue state of the driver can be estimated by grasping the data divergence (variation) regarding the driver's brake operation timing at this time.

Furthermore, in the present embodiment, as described above, when determining driver fatigue, the driver-specific characteristics such as operation characteristics are fatigued because it is based on the preference deceleration G _ave as statistical data of driver confidence. Considered in judgment.

  Therefore, according to the present embodiment, it is possible to easily and objectively determine the driver's fatigue while taking into consideration the driver-specific characteristics. As a result, it is possible to provide the driving fatigue determination device 1 that is inexpensive and highly robust.

  By the way, as a conventional driving fatigue determination device, the voice data of the driver of the host vehicle 10 is acquired, the feature amount is extracted from the acquired voice data, and the feature amount is compared with a predetermined determination value for driving. What determines a person's fatigue state is known. However, this conventional driving fatigue determination device requires a dedicated means for acquiring such audio data, which may increase the cost, and it is difficult to fully understand the characteristics of the individual driver. is there. In this respect, the present embodiment is particularly effective because it has the effect of easily determining driver fatigue while taking into account the driver-specific characteristics as described above.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, although the millimeter wave radar is used in the above embodiment, a laser sensor, a stereo camera, or the like may be used, and any sensor that can acquire the inter-vehicle distance from the preceding vehicle 50, the vehicle speed of the preceding vehicle 50, etc. A sensor can be used.

  In addition, when each of the stored value T (n), the stored value G (n), and the driver fatigue state S (n) that are function values is updated in S13, S19, and S28, the number of data is too large. If the data cannot be stored in the memory of the ECU 2, the past value may be discarded. In the above embodiment, the moving average technique is used as the statistical technique, but various other statistical techniques can be used.

It is a schematic block diagram which shows the driving | running fatigue determination apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of the own vehicle and a preceding vehicle in a follow-up driving state. It is a flowchart which shows the process of ECU in the driving | running fatigue determination apparatus of FIG. It is a flowchart which shows the continuation of FIG. 5 is a flowchart showing a continuation of FIG. 6 is a flowchart showing a continuation of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Driving fatigue determination apparatus, 2 ... ECU (running control means, statistical data acquisition means, current data acquisition means), 10 ... own vehicle, 50 ... preceding vehicle, _Gave ... preference deceleration (statistical data), _Gnow ... Expected deceleration (current data), S ... inter-vehicle distance, T ... inter-vehicle time, T _ave ... allowable inter-vehicle time.

Claims (3)

A driving fatigue determination device for determining fatigue of a driver of a host vehicle,
Traveling control means for monitoring that the vehicle is traveling while maintaining a distance between the preceding vehicle and the preceding vehicle;
Statistical data acquisition means for acquiring statistical data relating to the brake operation timing of the driver according to the deceleration of the preceding vehicle in a state in which the host vehicle travels following,
Current data acquisition means for acquiring current data relating to the current brake operation timing of the driver in a state in which the host vehicle maintains a distance between the preceding vehicle and the vehicle by the travel control means;
Fatigue determination means for determining fatigue of the driver based on the divergence between the statistical data acquired by the statistical data acquisition means and the current data acquired by the current data acquisition means, Driving fatigue judgment device.   2. The statistical data acquisition means estimates the deceleration of the host vehicle at a brake operation timing that is turned on from off, and acquires the deceleration statistics as the statistical data. Driving fatigue judgment device. The statistical data acquisition means includes
Calculate the inter-vehicle time based on the relative speed and the inter-vehicle distance of the host vehicle with respect to the preceding vehicle at the time of the brake operation timing from on to off, and obtain the statistics of the inter-vehicle time as the allowable inter-vehicle time,
3. The driving according to claim 2, wherein the deceleration is estimated based on a relative speed of the host vehicle with respect to the preceding vehicle, a distance between the vehicles, and the allowable inter-vehicle time at a brake operation timing that is turned on from off. Fatigue judgment device.

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