JP7320188B2 - Driver Abnormal Posture Detector - Google Patents

Description

The present invention relates to a driver posture detection device provided in a vehicle such as an automobile.

2. Description of the Related Art In recent years, in the driving of vehicles such as automobiles, there have been a series of traffic accidents due to sudden changes in the driver's physical condition during driving. According to statistics, about 10% of automobile accidents in Japan (30% in the case of commercial vehicles) are caused by changes in the driver's physical condition. In the analysis of traffic accidents caused by such sudden changes in the driver's physical condition (endogenous diseases, etc.), the driver's state immediately before the accident was affected by the collapse of the head posture due to loss of muscle tone, and the inability to face forward while driving. collapse has been found, and it is speculated that these are signs that an abnormality has occurred in the driver.

Detection of the driver's posture is essential for determining such driver anomalies, but with recent advances in the functionality of imaging means and the speeding up of numerical processing units, advanced image processing functions can be used at low cost. Therefore, by performing the recognition processing of the captured image of the driver in real time, it is possible to accurately recognize the driver state from the driver image, and based on this, highly accurate judgment of the abnormal state of the driver is performed. It is becoming possible to do so.

Therefore, in recent years, various techniques have been proposed for detecting the driver's posture using a camera or sensor installed in the vehicle and detecting an abnormality of the driver from the driver's posture. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2017-77817), a reference range of the head position of the driver of the vehicle is set, and in the image of the driver acquired by the image acquisition unit, the head position is specified. An invention has been proposed in which it is determined that there is an abnormal state when it does not fall within the reference range of .

JP 2017-77817 A

By the way, it is generally known that the posture of a driver varies greatly between individuals and driving scenes. For example, since there is an individual difference in height of 40 cm or more in the assumed physique of a driver, it is difficult to use the position of each part of the body (for example, the position of the head) in a normal posture as a standard. Conformity is essential. In addition, the position of the head constantly fluctuates on a vehicle with vibration, and the position of the head to be used as a reference fluctuates from moment to moment due to changes in the driver's conscious/unconscious posture (for example, leaning on the armrest). The first means of tracking such changes and calculating the reference position in a normal state is moving average processing. There is a concern that the driver abnormality cannot be determined correctly due to the time delay in position calculation.

FIG. 4 shows an example of the frequency distribution of the measured values of the driver's head position and the driver's face direction when the driver makes a large posture change (re-sitting). As can be seen from the figure, the measured values have different average values before and after the driver's posture change, so the frequency distribution has two peaks for a while. Therefore, during this period, there is a possibility that an appropriate reference value calculation will not be performed, and the occurrence of an abnormal posture of the driver cannot be accurately determined.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and its object is to detect an abnormal driver posture, which can appropriately determine whether an abnormal driver posture has occurred even when the driver has re-seated. to provide the equipment.

In order to achieve the above object, the present invention adopts the following solutions. That is, as described in claim 1, in a driver abnormal posture detection device provided in a vehicle, a photographing unit for photographing a driver and a measured value of the driver's head state based on the image of the driver photographed by the photographing unit a history generating unit that generates a history from the statistical data of the measured values of the driver's head state; and a reference value of the measured values of the driver's head state based on the history. and a reference value calculation unit, when the measured value of the driver's head state continues to deviate from the reference value by exceeding a predetermined threshold over a predetermined abnormality determination time, the driver has an abnormal posture. an abnormal posture determination unit that determines that an abnormal posture has occurred; a re-seat determination unit that determines whether or not the driver has re-seated based on the measured value of the driver's head condition; an abnormality determination time change unit for setting the abnormality determination time to a time longer than the standard time for a predetermined period when the determination is made , wherein the re-sitting determination unit changes the measurement value of the driver's head position and the driver's position. Based on the face direction measurement value, it is determined whether or not there is repositioning.

According to the above solution method, when the driver has to re-seat, the abnormality determination time is extended. It is possible to prevent an erroneous determination of an abnormal posture caused by In addition, it is possible to accurately determine whether the driver has re-seated based on the measured value of the driver's head state, which characterizes the re-seated state.

Preferred modes based on the above-described solution method are as described in claims 2 and subsequent claims. That is, the reference value calculation unit changes the history to a new history so as to match the driver's head condition after the re-sitting when the re-seating determination unit determines that the driver has re-seated . item 2 ). In this case, the reference value calculated based on the history can quickly follow the driver's repositioning.

According to the present invention, it is possible to accurately determine whether the driver's posture is abnormal even when the driver has re-seated.

1 is a block configuration diagram showing an example of a control system of the present invention; FIG. 4 is a flowchart showing an example of a control procedure for abnormality determination according to the present invention; Flowchart showing an example of a control procedure for history update and abnormality determination time change according to the present invention The figure which shows the moving average value of a driver's position when there exists a driver's re-seating.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an example of the control system of the driver abnormal posture detection device of the present invention. The driver posture detection device includes an in-vehicle camera 1 and a controller U as shown. The in-vehicle camera 1 is a photographing means capable of photographing the driver in the vehicle interior, photographs the state of the driver including the head (face) (for example, the driver's upper body), and transmits the photographed image to the controller U.

The controller U is a control device configured using a microcomputer, and includes a head position detection unit 11, a history generation unit 12, a reference value calculation unit 13, and an abnormal posture determination unit as processing means (program). 14 , a re-sitting determination unit 15 , and an abnormality determination time change unit 16 .

The driver's head state detection unit 11 analyzes the image of the driver acquired from the in-vehicle camera 1 to obtain the measured value of the driver's head state (specifically, the position and posture (angle) of the driver's head). calculate. Specific driver head states include, for example, the position of the driver's head, the orientation of the driver's face, and the like. Calculation of the measured value of the driver's head condition by the head condition calculator 11 is repeated at predetermined detection intervals.

The history generation unit 12 generates a history (population for calculating statistics) from the time-series data of the measured values of the driver's head state detected by the driver's head state detection unit 11 . The history is composed of time-series data of measured values over a predetermined period up to the present, and is updated as needed based on the current measured values of the driver's head condition. That is, the history is updated by adding the current measured value of the driver's head state and discarding the oldest measured value data.

The reference value calculation unit 13 calculates the median value of the current history generated by the history generation unit 12 (or the moving average value of the measurement values of the driver's head state included in the history), and calculates the median value (or the moving average value) as the current reference value.

The abnormal posture determination unit 14 compares the current value of the measured value of the driver's head state with the reference value calculated by the reference value calculation unit 13, and determines that the deviation of the measured value from the reference value exceeds a predetermined threshold. However, if it continues beyond a predetermined abnormality determination time, it is determined that an abnormality in the driver's posture (disturbance of posture due to change in physical condition, etc.) has occurred.

The resit determination unit 15 determines whether or not the driver has reseated in the driver's seat based on the measured values of the driver's head position and face direction acquired from the driver's head state detection unit 11 . Here, the re-sitting in the present application broadly includes the case where the driver continues to drive normally but the driving posture changes significantly (for example, when the elbow rests on the armrest). It is determined as an action in which the head position (face position) changes abruptly, but the face orientation does not change abruptly.

It should be noted that reseat in the present application includes not only the case where the same driver greatly changes his/her posture, but also the case where the driver who is driving is replaced by another driver with a different physique. In other words, even when the head position of the driver changes significantly due to a change in driver, the same process can be performed in the same way as when the same driver changes the posture and the head position changes significantly.

The re-sitting determination unit 15 includes a head position determination unit 21 that determines whether the measured value of the driver's head position has changed suddenly by exceeding a predetermined threshold value (for example, 3%), and a head position determination unit 21 that measures the direction of the driver's face. A face orientation determination unit 22 is provided to determine whether or not the value has changed abruptly beyond a predetermined threshold. If not, it is determined that the driver has re-seated.

When the re-sitting determination unit 15 determines that there is a re-sitting (when the head position determination unit 21 determines that there is a sudden change in the position of the driver's head), the history generation unit 11 generates a history. Change to a new history adapted to the measured value after the driver re-seated (sudden head position change). For example, using the variance value σ of the history at the time of judgment and the average value μ of the measured values detected during the judgment time, a normal distribution having the variance value σ and the median value μ is generated with random numbers, and a new history ( population). As a result, the reference value calculated by the reference value calculation unit 13 quickly follows the driver's repositioning.

The abnormality determination time changing unit 16 changes the abnormality determination time in the abnormal posture determination unit 14 to a time longer than the standard time (eg, 2 seconds) (eg, 10 seconds). By providing a margin in the abnormality determination time in this way, even if there is a time delay before the appropriate reference value calculation after re-sitting, an erroneous determination by the abnormal posture determination unit 14 due to this occurs. You can avoid it. The extension of the abnormality determination time is continued for a predetermined period of time, and after the predetermined period of time (after the reference value becomes a value reflecting the driver's posture after sitting down), the abnormality determination time is returned to the standard time.

Next, an example of control for abnormality detection by the abnormal driver posture detection device of the present invention will be described with reference to the flowchart of FIG. In the control, first, in step S1, the current value of the measured value of the driver's head state is acquired. In the subsequent step S2, it is determined whether or not the vehicle is running based on the vehicle speed.

On the other hand, when the vehicle is running, the process proceeds to step S3, where the measured value of the driver's head condition is compared with the reference value to determine whether there is an abnormal posture (that is, the threshold value of the measured value and the reference value is (whether or not there is a divergence exceeding) is made. If it is determined that there is no abnormal posture, the process proceeds to step S6, it is determined that there is no abnormality, and one round of processing ends.

If it is determined in step S3 that there is an abnormal posture, the process proceeds to step S4, in which it is determined whether or not the abnormal posture has continued beyond the abnormality determination time. If so, it is determined that the posture of the driver is only temporarily disturbed, and the process advances to step S6 to determine that there is no abnormality, and completes one round of processing.

On the other hand, if the abnormal posture continues beyond the abnormality determination time, it is determined that an abnormality such as a sudden change in physical condition has occurred in the driver, the process proceeds to step S5, and it is determined that there is an abnormality, and the processing cycle ends. .
Next, an example of control for history update and abnormality determination time change by the abnormal driver posture detection device of the present invention will be described with reference to the flowchart of FIG. In the control, first, in step S11, the current value of the measured value of the driver's head state is obtained. In the subsequent step S12, it is determined whether or not the vehicle is running based on the vehicle speed.

On the other hand, if the vehicle is running, the process proceeds to step S13, where it is determined whether or not there is a sudden change in the driver's head position. After updating, the process proceeds to step S18, the reference value is calculated (updated) based on the updated history, and one round of processing ends.

If it is determined in step S13 that there has been a sudden change in the driver's head position, the process advances to step S15 to determine whether or not there has been a sudden change in the direction of the driver's face. If it is determined from this determination that there is no sudden change in the direction of the driver's face, it is determined that the driver has re-seated, and the process proceeds to step S16, where the abnormality determination time is set to extend from the standard time for a predetermined period of time. Proceed to S17. On the other hand, if there is no sudden change in the orientation of the driver's face, the process proceeds directly to step S17.

In step S17, a new history is generated from the variance value and the current value of the past history, and in subsequent step S18, a reference value is calculated based on the new history, and one round of processing ends.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made within the scope of the claims.

INDUSTRIAL APPLICABILITY The present invention can be used to detect driver anomalies based on driver posture in vehicles such as automobiles.

1 In-vehicle camera 11 Driver head state detection unit 12 History generation unit 13 Reference value calculation unit 14 Abnormal posture determination unit 15 Re-sitting determination unit 16 Abnormal determination time change unit 21 Head position determination unit 22 Face orientation determination unit

Claims (2)

In a driver abnormal posture detection device provided in a vehicle,
a photographing unit for photographing the driver;
a driver head state detection unit that calculates a measured value of the driver's head state based on the image of the driver captured by the imaging unit;
a history generation unit that generates a history from statistical data of measured values of the driver's head state;
a reference value calculation unit that calculates a reference value of the measured value of the driver's head state based on the history;
Abnormality in which it is determined that an abnormal posture has occurred in the driver when the measured value of the driver's head state continues to deviate from the reference value beyond a predetermined abnormality determination time and exceeds a predetermined threshold. a posture determination unit;
a resit determination unit that determines whether or not the driver should reseat based on the measured value of the driver's head state;
an abnormality determination time changing unit that sets the abnormality determination time to a time longer than a standard time for a predetermined period when the reseating determination unit determines that the driver has re-seated ,
The re-sitting determination unit is a driver abnormal posture detection device that determines whether or not re-sitting is performed based on the measured value of the head position of the driver and the measured value of the orientation of the driver's face. In the driver posture detection device according to claim 1 ,
The reference value calculation unit detects an abnormal driver posture by changing the history to a new history so as to match the driver's head state after the driver has re-seated when the re-seating determination unit determines that the driver has re-seated. Device.

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