Driving distraction warning method and system

Abstract

A driving distraction warning method is implemented by a driving distraction warning system arranged on a vehicle. The driving distraction warning method comprises the following steps: (A) judging whether a face meets a stable condition or not according to an activity situation of the face presented by an instant dynamic image; (B) when it is determined that the face meets the stable condition, adjusting a default angle range according to the angle represented by the face to determine a correction angle range; and (C) judging whether the face meets a distraction warning condition or not according to the correction angle range and the movement condition of the face, and outputting a distraction warning notice if the judgment result is yes.

Description

Technical Field

[0001] The present invention relates to a warning method, and particularly to a driving distraction warning method suitable for vehicle driving. The present invention also relates to a driving distraction warning system suitable for vehicle driving. Background Art

[0002] In recent years, image recognition has been widely applied to various vehicles and is regarded as one of the core technologies for enhancing driving safety. For example, one of the existing techniques is to use image recognition to detect the direction in which the driver's face is facing, and based on this, determine whether the driver is distracted during driving, and thus output a warning when it is determined that the driver is distracted.

[0003] The above method often needs to detect the driving direction of the vehicle and compare the driving direction of the vehicle with the face direction of the driver, so as to confirm whether the driver's face is not facing the driving direction of the vehicle, and then determine whether the driver is distracted. However, the driving direction of the vehicle often needs to be sensed by a motion sensor (such as an acceleration sensor), so it will increase the cost and limitations of the overall system in terms of hardware. In view of this, how to improve the existing technology to provide a brand-new driving distraction warning mechanism has become the issue to be explored in this case. Summary of the Invention

[0004] Therefore, one object of the present invention is to provide a driving distraction warning method that does not need to detect the driving direction of the vehicle.

[0005] The driving distraction warning method of the present invention is implemented by a driving distraction warning system suitable for being set in a vehicle. The driving distraction warning method includes: (A) judging whether the face conforms to a stability condition according to the activity condition of a face presented in an instant dynamic image; (B) in the case of determining that the face conforms to the stability condition, adjusting a default angle range according to the angle shown by the face in the instant dynamic image to determine a corrected angle range, wherein the corrected angle range is used to define the posture that the face in the instant dynamic image is allowed to present; (C) judging whether the face conforms to a distraction warning condition according to the corrected angle range and the activity condition of the face presented in the instant dynamic image, and outputting a distraction warning notification when it is determined that the face conforms to the distraction warning condition.

[0006] In some embodiments of the driving distraction warning method of the present invention, in step (A), the stability condition includes: an average angle change amount of the face presented in the instant dynamic image within a detection period is less than or equal to an average angle threshold.

[0007] In some embodiments of the driving distraction warning method of the present invention, in step (A), the processing unit starts to determine whether the face meets the stable condition only when it determines that the current driving speed of the vehicle is greater than or equal to a speed threshold.

[0008] In some embodiments of the driving distraction warning method of the present invention, in step (B), the processing unit determines the corrected angle range according to a default angle range and a key angle shown by the face during a detection period, wherein the key angle is related to the shooting direction of a shooting unit that generates the instant dynamic image.

[0009] In some embodiments of the driving distraction warning method of the present invention, in step (C), the distraction warning condition includes: the angle presented by the face in the instant dynamic image exceeds the corrected angle range, and the duration of exceeding the corrected angle range exceeds a default time length threshold.

[0010] Another object of the present invention is to provide a driving distraction warning system that does not need to detect the driving direction of a vehicle.

[0011] The driving distraction warning system of the present invention is suitable for being arranged in a vehicle, and includes a shooting unit for generating an instant dynamic image, and a processing unit electrically connected to the shooting unit, wherein the processing unit is used for: judging whether the face meets a stable condition according to the activity situation of a face presented by the instant dynamic image; under the condition of judging that the face meets the stable condition, adjusting a default angle range according to the angle shown by the face in the instant dynamic image to determine a corrected angle range, wherein the corrected angle range is used to define the posture that the face in the instant dynamic image is allowed to present; judging whether the face meets a distraction warning condition according to the corrected angle range and the activity situation of the face presented by the instant dynamic image, and outputting a distraction warning notification when judging that the face meets the distraction warning condition.

[0012] In some embodiments of the driving distraction warning system of the present invention, the stable condition includes: an average angle change amount of the face presented by the instant dynamic image during a detection period is less than or equal to an average angle threshold.

[0013] In some embodiments of the driving distraction warning system of the present invention, the processing unit starts to judge whether the face meets the stable condition only when it judges that the current driving speed of the vehicle is greater than or equal to a speed threshold.

[0014] In some embodiments of the driving distraction warning system of the present invention, the processing unit determines the correction angle range according to a default angle range and a key angle exhibited by the face during a detection period, wherein the key angle is related to the shooting direction of the shooting unit.

[0015] In some embodiments of the driving distraction warning system of the present invention, the distraction warning condition includes: the angle exhibited by the face in the instant dynamic image exceeds the correction angle range, and the duration of exceeding the correction angle range exceeds a default time length threshold.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: when the driving distraction warning system determines that the face meets the stable condition, it can adjust the default angle range according to the angle exhibited by the face in the instant dynamic image to determine the correction angle range, and then judge whether the driving is distracted according to the correction angle range and the face presented in the instant dynamic image. Thus, the driving distraction warning system can use image recognition to detect whether the driving is distracted without using a motion sensor to sense the driving direction of the vehicle, which helps to reduce the cost and limitations of the hardware in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein:

[0018] Figure 1 is a block diagram, exemplarily showing an embodiment of the driving distraction warning system of the present invention; and

[0019] Figure 2 is a flowchart, used to exemplarily illustrate how the embodiment implements a driving distraction warning method. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Before the present invention is described in detail, it should be noted that: without special definition, the "electrically connected" described in this patent specification is used to describe the "coupled" relationship between computer hardware (such as electronic systems, devices, apparatuses, units, components), and generally refers to the "wired electrical connection" realized by physically connecting plural computer hardware to each other through conductor / semiconductor materials, and the "radio connection" realized by using wireless communication technologies (such as but not limited to wireless networks, Bluetooth, and electromagnetic induction, etc.) for wireless data transmission. On the other hand, without special definition, the "electrically connected" described in this patent specification also generally refers to the "direct electrical connection" realized by directly coupling plural computer hardware to each other, and the "indirect electrical connection" realized by indirectly coupling plural computer hardware through other computer hardware.

[0021] Before the present invention is described in detail, it should be noted that the "unit" described in this patent specification may refer to a single computer hardware with a specific function, or a group of computer hardwares with similar functions. For example, the "processing unit" may refer to a single processor with data processing function, but may also refer to a set of processors.

[0022] Refer to Figure 1 , an embodiment of the driving distraction warning system 1 of the present invention is suitable for being disposed in a vehicle (not shown in the figure), and the driving distraction warning system 1 includes a storage unit 11, a positioning unit 12, an output unit 13, a photographing unit 14, and a processing unit 15 electrically connected to the storage unit 11, the positioning unit 12, the output unit 13, and the photographing unit 14. Among them, the vehicle may be, for example, a four-seater car. However, this embodiment can also be applied to cars with seven seats, nine seats, as well as large vehicles such as trucks and buses.

[0023] In this embodiment, the driving distraction warning system 1 is implemented as, for example, a driving recorder and is suitable for being disposed on the rearview mirror of the vehicle. The storage unit 11 is a non-volatile memory capable of storing digital data (such as, but not limited to, flash memory). The positioning unit 12 is a satellite positioning module implemented by using satellite positioning technology, which is configured to receive satellite signals from the Global Positioning System (i.e., GPS system), and calculate its own current position and moving speed (equivalent to the current position and moving speed of the vehicle). The photographing unit 14 is a video recording module with a lens and is suitable for being disposed to face the driver's seat of the vehicle. Thus, the photographing unit 14 can continuously photograph the face of the driver during the process of the vehicle being driven by a driver. The output unit 13 has, for example, a speaker. However, in other embodiments, the output unit 13 may further have components capable of outputting sensory cues such as light-emitting diodes, vibrators, etc. The processing unit 15 is a processor implemented by integrated circuits and having data operation and instruction transceiver functions.

[0024] It should be further noted that, in this embodiment, the driving distraction warning system 1 can be independently manufactured and sold, and is, for example, installed on the vehicle after the vehicle leaves the factory. However, in other embodiments, the driving distraction warning system 1 may also be built into the vehicle before the vehicle leaves the factory. In other words, the driving distraction warning system 1 is not limited to being implemented as an independent driving recorder. Moreover, in other embodiments, the processing unit 15 may also be a set of one or more processors, and may be the vehicle's on-board computer itself, or a part of the vehicle's on-board computer. Therefore, the actual implementation of the driving distraction warning system 1 in terms of computer hardware is not limited to this embodiment.

[0025] In this embodiment, the storage unit 11 stores a speed parameter P1, an average angle parameter P2, an angle range parameter P3, and a time length parameter P4. Among them, the value of the speed parameter P1 indicates a speed threshold, the value of the average angle parameter P2 indicates an average angle threshold, the value of the angle range parameter P3 indicates a default angle range, and the value of the time length parameter P4 indicates a default time length threshold. Specifically, for example, the speed threshold may be "35 km / h", the average angle threshold may be "8°", the default angle range may be "-10° to 10°", and the default time length threshold may be "3 seconds". However, it should be understood that the values of the above parameters can be freely adjusted according to different situations and requirements. Therefore, the actual values of the speed threshold, the average angle threshold, the default angle range, and the default time length threshold are not limited to the examples given above.

[0026] With reference to Figure 2 , the following exemplarily and specifically describes how the driving distraction warning system 1 of this embodiment implements a driving distraction warning method. It should be pre-stated that the driving distraction warning method is implemented when the vehicle is driven by a driver after the vehicle switches from an off state to an on state.

[0027] First, in step S1, the processing unit 15, for example, obtains a speed calculation result generated by the positioning unit 12 based on multiple positioning results from the positioning unit 12, and determines whether the current driving speed of the vehicle is greater than or equal to the speed threshold indicated by the speed parameter P1 (such as but not limited to "35 km / h") according to the speed calculation result. If the judgment result of the processing unit 15 is yes, the process proceeds to step S2. On the other hand, if the judgment result of the processing unit 15 is no, the process starts again from step S1 when a predetermined delay period ends.

[0028] More specifically, in this embodiment, the processing unit 15 directly uses the speed calculation result generated by the positioning unit 12 as the current driving speed of the vehicle. However, in other embodiments, if the processing unit 15 is electrically connected to the vehicle's on-board computer, the processing unit 15 can also receive the current driving speed of the vehicle from the on-board computer. Or, if the processing unit 15 itself is the vehicle's on-board computer or a part thereof, the processing unit 15 can also obtain a rotational speed sensing result indicating the current driving speed from a rotational speed sensor in the vehicle's transmission. In this way, in the above other embodiments, the driving distraction warning system 1 does not need to include the positioning unit 12.

[0029] In step S2 following step S1, once the processing unit 15 determines that the current driving speed of the vehicle is greater than or equal to the speed threshold, the processing unit 15 obtains from the imaging unit 14 an instant dynamic image generated by the imaging unit 14 during video recording, and determines whether the face (i.e., the face of the driver) conforms to a stability condition according to the movement situation of the face presented in the instant dynamic image. If the judgment result of the processing unit 15 is yes, the process proceeds to step S3. On the other hand, if the judgment result of the processing unit 15 is no, the process, for example, starts again from step S1.

[0030] More specifically, in this embodiment, once the processing unit 15 starts to determine whether the face conforms to the stability condition, the processing unit 15 calculates a detection period while continuously detecting the change in the direction of the face in the instant dynamic image (equivalent to detecting the rotation of the driver's head) to calculate an average angle change amount shown by the face during the detection period. In this embodiment, the detection period starts from when the processing unit 15 starts to determine whether the face conforms to the stability condition. The average angle change amount is the average rotation angle of the face per unit time during the detection period. For example, assuming that the time length of the detection period is 15 seconds and the processing unit 15 determines that the total left - right rotation angle of the face during the detection period is "150°", then the average angle change amount calculated by the processing unit 15 is "10° / second". It should be added that in different embodiments, the time length of the detection period can also be 10 seconds, 60 seconds, 180 seconds or other different time lengths, and moreover, the average angle change amount can also be calculated by the processing unit 15 according to the cumulative up - down and left - right rotation angles of the face during the detection period, and is not limited to this embodiment. Since using image recognition technology to recognize the direction of the face in the image belongs to the prior art, the details thereof are not specifically described here.

[0031] On the other hand, in this embodiment, the stability condition means that the average angle change amount of the face presented in the instant dynamic image during the detection period is less than or equal to the average angle threshold indicated by the average angle parameter P2 (such as but not limited to "8°"). Specifically, if the face presented in the instant dynamic image conforms to the stability condition, it means that the cumulative rotation angle of the driver's head during the detection period is relatively small. It is worth noting that in this embodiment, the processing unit 15 starts to determine whether the face conforms to the stability condition only when it determines that the current driving speed of the vehicle is greater than or equal to the speed threshold. Therefore, when the driving speed of the vehicle has reached the speed threshold and the face conforms to the stability condition, it can be reasonably inferred that the driver's face is facing the front of the vehicle, that is, the situation of turning the head due to distraction does not occur.

[0032] In step S3 following step S2, once the processing unit 15 determines that the face meets the stable condition, the processing unit 15 adjusts the default angle range (such as but not limited to "-10° to 10°") indicated by the angle range parameter P3 according to the angle shown by the face in the instant dynamic image to determine a corrected angle range. Wherein, the corrected angle range is used to define the posture that the face in the instant dynamic image is allowed to present. More specifically, in this embodiment, the corrected angle range is used to hypothetically define the appropriate angle range that the face should present in the instant dynamic image when the face of the driver is generally facing the front of the vehicle (that is, the driver does not turn his head due to distraction).

[0033] The angle of the face relative to the imaging unit 14 is calculated through a 3D model. Specifically, the imaging unit 14 obtains the coordinates of some position points of the face, and at the same time obtains some parameters of the imaging unit 14, such as: focal length, parallax or distortion, etc. for calibration or calculation. The algorithm POSIT included in OpenCV can be used to achieve this, which belongs to the prior art, so no more description will be made. In this embodiment, the processing unit 15 adjusts the default angle range with a key angle shown by the face in the instant dynamic image during the detection period to determine the corrected angle range. For the convenience of explaining the key angle, the opposite direction of the shooting direction of the imaging unit 14 is used as a reference direction here. That is to say, if the face of the driver is completely facing the lens of the imaging unit 14 and there is no deflection compared to the lens, then his face is equivalent to facing the reference direction. More specifically, in this embodiment, the key angle is the average angle difference in the left-right rotation direction between the direction the face faces during the detection period and the reference direction, that is, with the reference direction as the axis, the average angle difference in its yaw direction. Specifically, for example, if the processing unit 15 calculates that the average angle difference between the direction the face faces during the detection period and the reference direction is "23° to the left", then the processing unit 15 will, for example, calculate a key angle of "-23°". However, in a similar embodiment, the key angle can also be the average angle difference in the up-down and left-right rotation directions between the direction the face faces during the detection period and the reference direction, that is, with the reference direction as the axis, the average angle difference in its yaw and pitch directions.

[0034] Further, in this embodiment, the processing unit 15 determines the correction angle range by adjusting the default angle range with the key angle. Continuing with the previous example, assuming the default angle range is "-10° to 10°" and the key angle is "-23°", the processing unit 15 can, for example, add the "-10°" in the default angle range to the key angle to calculate "-33°" (-10° - 23° = -33°), and use this as a first boundary angle of the correction angle range. Then, add the "10°" in the default angle range to the key angle to calculate "-13°" (10° - 23° = -13°), and use this as a second boundary angle of the correction angle range. Thus, in this example, the processing unit 15 will determine the correction angle range as "-33° to -13°".

[0035] By the processing unit 15 adjusting the default angle range according to the key angle to determine the correction angle range, even if the lens of the photographing unit 14 is not directly facing the driver's face (for example, the photographing unit 14 shoots the driver from the front right of the driver), the processing unit 15 can also correct the angle deviation between "the shooting direction of the photographing unit 14" and "the direction when the driver's face faces the front of the vehicle" by determining the correction angle range, thereby defining at what angle the face appears in the instant dynamic image, which means the driver's face is generally facing the front of the vehicle. Thus, on the premise that the photographing unit 14 can capture the driver's face, the driver distraction warning method is not limited by the installation angle of the photographing unit 14.

[0036] After the processing unit 15 determines the correction angle range, the process proceeds to step S4.

[0037] In step S4, the processing unit 15 performs a distraction detection process according to the correction angle range and the activity situation of the face presented in the instant dynamic image. Specifically, the distraction detection process includes determining whether the face meets a distraction warning condition, and when it is determined that the face meets the distraction warning condition, outputting a distraction warning notification through the output unit 13 (for example, controlling the speaker to emit a warning sound). More specifically, in this embodiment, the distraction warning condition means that the angle shown by the face in the instant dynamic image exceeds the correction angle range, and the duration of exceeding the correction angle range exceeds the default time length threshold indicated by the time length parameter P4 (such as but not limited to 3 seconds).

[0038] The above is an example description of how the driver distraction warning system 1 in this embodiment implements the driver distraction warning method.

[0039] It should be specifically noted that steps S1 to S4 in this embodiment andFigure 2 The flowchart is only one of the implementable ways for exemplifying the driving distraction warning method of the present invention. It should be understood that even if steps S1 to S4 are combined, split, or the order is adjusted, if the process after the combination, splitting, or order adjustment achieves substantially the same effect in a substantially the same manner as this embodiment, it still belongs to the implementable aspects of the driving distraction warning method of the present invention. Therefore, steps S1 to S4 of this embodiment and Figure 2 the flowchart are not used to limit the implementable scope of the present invention.

[0040] In this embodiment, the processing unit 15 calculates the average angle change amount, determines whether the face meets the stable condition, calculates the key angle, determines the correction angle range, and performs the distraction detection process according to "the direction the face is facing". However, in another embodiment of the present invention, the processing unit 15 uses "the line-of-sight direction of the eyes of the face" to replace "the direction the face is facing" to calculate the average angle change amount, determine whether the face meets the stable condition, calculate the key angle, determine the correction angle range, and perform the distraction detection process.

[0041] Specifically, in the said another embodiment, the activity situation of the face refers to the rotation situation of the driver's eyeballs. The average angle change amount is the average rotation angle of the driver's line-of-sight direction per unit time during the detection period. The key angle is the average angle difference between the direction the driver's line-of-sight direction faces during the detection period and the reference direction. The "posture that the face in the instant dynamic image is allowed to present" defined by the correction angle range refers to the allowed angle range of the driver's line-of-sight direction in the instant dynamic image. And the distraction warning condition means that the angle shown by the driver's line-of-sight direction in the instant dynamic image exceeds the correction angle range, and the duration exceeding the correction angle range exceeds the default time length threshold. Since using image recognition technology to recognize the line-of-sight direction of the two eyes of the face belongs to the prior art, the details thereof are not specifically described herein.

[0042] In summary, by implementing the driving distraction warning method, the driving distraction warning system 1 can calculate the key angle shown by the face according to the instant dynamic image when it is determined that the face meets the stable condition, then adjust the default angle range according to the key angle to determine the correction angle range, and further determine whether the driver is distracted according to the correction angle range and the face presented in the instant dynamic image. Thus, the driving distraction warning system 1 can detect whether the driver is distracted using image recognition without using a motion sensor to sense the vehicle driving direction, which helps to reduce the costs and limitations in terms of hardware in the prior art, so it can indeed achieve the purpose of the present invention.

[0043] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A driving distraction warning method, implemented by a driving distraction warning system adapted to be set in a vehicle; characterized in that, The driving distraction warning method includes: (A) judging whether the face meets a stability condition according to the activity condition of a face presented in an instant dynamic image; (B) when it is determined that the face meets the stability condition, adjusting a default angle range according to the angle shown by the face in the instant dynamic image to determine a corrected angle range, wherein the corrected angle range is used to define the posture that the face in the instant dynamic image is allowed to present; and (C) judging whether the face meets a distraction warning condition according to the corrected angle range and the activity condition of the face presented in the instant dynamic image, and outputting a distraction warning notification when it is determined that the face meets the distraction warning condition.

2. The driving distraction warning method according to claim 1, wherein In step (A), the stability condition includes: an average angle change amount of the face presented in the instant dynamic image within a detection period is less than or equal to an average angle threshold.

3. The driving distraction warning method according to claim 1, wherein In step (A), the processing unit starts to judge whether the face meets the stability condition only when it is determined that the current driving speed of the vehicle is greater than or equal to a speed threshold.

4. The driving distraction warning method according to claim 1, wherein In step (B), the processing unit determines the corrected angle range according to a default angle range and a key angle shown by the face within a detection period, wherein the key angle is related to the shooting direction of a shooting unit that generates the instant dynamic image.

5. The driving distraction warning method according to claim 1, wherein, In step (C), the distraction warning condition includes: the angle presented by the face in the instant dynamic image exceeds the corrected angle range, and the duration of exceeding the corrected angle range exceeds a default time length threshold.

6. A driving distraction warning system, suitable for being set in a vehicle, characterized in that, Includes: a shooting unit for generating an instant dynamic image; and a processing unit electrically connected to the shooting unit and configured to: judge whether the face meets a stability condition according to the activity condition of a face presented in the instant dynamic image; when it is determined that the face meets the stability condition, adjust a default angle range according to the angle shown by the face in the instant dynamic image to determine a corrected angle range, wherein the corrected angle range is used to define the posture that the face in the instant dynamic image is allowed to present; judge whether the face meets a distraction warning condition according to the corrected angle range and the activity condition of the face presented in the instant dynamic image, and output a distraction warning notification when it is determined that the face meets the distraction warning condition.

7. The driving distraction warning system according to claim 6, wherein The stability condition includes: an average angle change amount of the face presented in the instant dynamic image within a detection period is less than or equal to an average angle threshold.

8. The driving distraction warning system according to claim 6, wherein, The processing unit starts to judge whether the face meets the stability condition only when it is determined that the current driving speed of the vehicle is greater than or equal to a speed threshold.

9. The driving distraction warning system according to claim 6, wherein The processing unit determines the corrected angle range according to a default angle range and a key angle shown by the face within a detection period, wherein the key angle is related to the shooting direction of the shooting unit.

10. The driving distraction warning system according to claim 6, characterized in that, The distraction warning condition includes: the angle of the face shown in the instant dynamic image exceeds the corrected angle range, and the duration of exceeding the corrected angle range exceeds a default time length threshold.

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