JP2013143026A - Vehicle driver's state detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driver's state detecting system capable of detecting such a driving state as calling for the driver's attention at a high probability without being affected by driving environment or worn objects.SOLUTION: The vehicle driver's state detecting system includes a multiaxial force sensor 21 including one axis (Fz) coaxially disposed with a steering shaft, and means (20) for determining the driver's operation or non-operation of a steering wheel on the basis of a detection value of the multiaxial force sensor. The system further includes a traveling state determination part (10) and, when the driver's specific operation or non-operation of the steering wheel that is determined based on the detection value of the multiaxial force sensor continues for a predetermined time or more in a specific traveling state determined by the traveling state determination part, this system actuates attention-calling means (30).

Description

  The present invention relates to a system for detecting the state of a driver who is driving.

  The driver's level of consciousness may be due to tasks other than driving, such as the operation of in-vehicle devices or the act of reaching for an article placed in the passenger seat, resulting in a low concentration of driving or sleepiness. As a technique for detecting the lowered state, a technique for detecting the closed eye state and the direction of the line of sight from a driver's captured image is generally used. However, when using cameras, the effects of ambient light such as sunlight and headlights of oncoming vehicles, and the effects of physical obstacles such as glasses, sunglasses, and masks become problems, and it is necessary to develop technology to avoid them. Become.

  Patent Document 1 proposes detecting the fluctuation of the pressure distribution of the seat seat surface based on the driver's state. However, there are problems that it is impossible to detect unless the driver's seating posture changes greatly, and that it is difficult to set a discrimination criterion because the driver usually performs an operation of re-sitting frequently.

  Patent Document 2 proposes detecting the operation frequency of switches such as audio and car navigation systems. However, when operating while confirming feedback on the operation, or when thinking about the operation after touching the switch, it is not possible to detect a state where the frequency of operation is low, but being distracted by tasks other than driving, The operation of the passenger in the passenger seat was also detected.

JP 2009-126209 A JP 2009-120013 A

  The present invention has been made in view of the above circumstances, and its purpose is not affected by the driving environment or wearing items, and the driver can detect the driving state to alert the driver with high probability. It is to provide a state detection system.

  In order to solve the above problems, the present invention is based on a multi-axis force sensor (21) including one axis (Fz) coaxially arranged with a steering shaft (1), and a detection value of the multi-axis force sensor. A vehicle comprising: means (20) for determining whether or not the driver operates the steering wheel.

  The vehicle determines the driver's seating posture, wear, sun, and the like by determining whether the driver is operating or not operating the steering wheel using a multi-axis force sensor disposed substantially in the center of the steering wheel. Dangerous driving with a reduced level of consciousness due to drowsiness and other driving conditions that should alert the driver, while eliminating the effects of ambient light such as light and headlights from oncoming vehicles, and passenger passenger operations. The state can be detected with high probability.

  More specifically, the present invention includes a vehicle traveling state determination unit (10) and a multi-axis force sensor (21) including one axis (Fz) coaxially arranged with the steering shaft (1), When the specific operation or non-operation on the steering wheel of the driver determined based on the detection value of the multi-axis force sensor continues for a predetermined time or more in the specific driving state of the vehicle determined by the driving state determination unit In the vehicle driver state detection system, the warning means (30) is configured to be activated.

  Dangerous driving conditions with a low level of consciousness due to drowsiness etc. are likely to occur on straight and high-speed sections such as highways and main roads, and are likely to develop into serious accidents. Therefore, it is possible to perform detection with higher accuracy by determining such a specific driving situation by the traveling state determination unit of the vehicle, and excluding it from the detection target in other cases.

  From such a viewpoint, the traveling state determination unit (10) determines whether the vehicle is in a straight traveling state or a quasi-straight line based on detection values of the vehicle speed sensor (11) and the steering angle sensor (12) as the specific traveling state of the vehicle. It is preferable to be optimized to determine that the vehicle is in a running state.

  With the configuration described above, the driver state detection system according to the present invention can detect the driving state to alert the driver with high probability without being affected by the driving environment and wearing items.

It is a conceptual diagram which shows the driver | operator state detection system which concerns on this invention. It is a sectional side view (a) which shows the installation condition of the force sensor to a steering wheel, and an A direction arrow line view (b). It is a flowchart which shows the determination process of the driver | operator state detection system concerning this invention. It is a graph which shows the driver | operator state detection based on a steering axial direction load. It is a graph which shows the driver | operator state detection based on a lateral direction torque.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
In FIG. 1, a driver state detection system according to an embodiment of the present invention includes a traveling state determination unit 10 that determines a traveling state of a vehicle, a force sensor 21 attached to the steering wheel 2, a driver state determination unit 20, and a normal operation. The data storage device 22, the alerting means 30, and the like are included.

  The traveling state determination unit 10 has a function of determining the traveling state of the vehicle based on various detection values during driving of the vehicle and the operation state of the driver. For example, the various detection values are compared with the set values and the results are determined according to the results. A CPU and a memory that are operable to output a signal to the driver state determination unit 20 are configured. In the driver state detection system of this embodiment, the detection values of the vehicle speed sensor 11 and the steering angle sensor 12 are compared with set values, and the vehicle takes a straight line in consideration of the operation state of the turn signal switch (turn signal switch) 13. It is optimized to determine whether the vehicle is in a traveling state or a quasi-straight traveling state, in other words, not in the traveling state.

  As the force sensor 21, for example, a 6-axis force sensor capable of detecting load values in three-axis directions of orthogonal coordinates in a three-dimensional space and torque values around those axes can be suitably used. One of the three orthogonal coordinate axes of the sensor (z-axis in the illustrated example) is disposed on the hubs 23 and 24 of the steering wheel 2 so as to be coaxial with the steering shaft 1. When the strength of the housing of the general-purpose 6-axis force sensor (allowable load of the 6-axis force sensor) does not reach the safety standard of the automobile, the maximum displacement in the respective axial directions between the hubs 23 and 24 is set. A support structure that regulates and allows sensing within the range may be provided.

  The driver state determination unit 20 determines whether or not the vehicle is in a specific travel state (straight line travel state or quasi-straight line travel state) by the travel state determination unit 10 and the load value detected by the force sensor 21 and its direction. The combined condition is compared with the normal operation data stored in the normal operation data storage device 22, and it is determined that the driver is in the dangerous driving state when the state deviating from the threshold value based on the normal driving data continues for a predetermined time or more. In addition, a CPU and a memory operable to output a signal corresponding to the result to the alerting means 30 are configured. The normal operation data storage device 22 includes a storage element such as a flash memory. The driver state determination unit 20 is preferably configured as a program that can operate on a common system with the traveling state determination unit 10.

  The alerting means 30 can be used as an alarm for notifying the driver of dangerous driving conditions by voice, a vibrator for notifying by vibration, or a combination thereof. Furthermore, when the vehicle has an automatic steering system, risk avoidance measures such as shifting from the manual driving state to the automatic driving may be executed. In this case, it is needless to say that it is preferable to use a warning and notification to the driver together.

  Next, an example of the determination process of the dangerous driving state by the driver state detection system as described above will be described based on the flowchart shown in FIG.

  When the driver state detection system is started, first, the vehicle speed V detected by the vehicle speed sensor 11 is compared with the set speed Vs by the travel state determination unit 10, and when it is equal to or less than the set speed Vs, it is determined that the vehicle is in the low speed travel state. . In such a low-speed running (slow-down) state, the possibility of dangerous driving leading to a large accident is low, so it is excluded from the detection target.

  In the experiment, when the set speed Vs was set to 30 km / h, unnecessary detection was not performed and a good detection result was obtained. Since this set speed Vs depends on the driving experience of the driver and individual differences, it is preferable to set it as a user preset. In this case, for example, the set speed Vs can be set between an upper limit value of 40 to 50 km / h with a speed of 30 km / h as a default value (lower limit value).

  Next, when it is determined that the vehicle speed V is greater than the set speed Vs, the steering angle θ detected by the steering angle sensor 12 is compared with the set value θs. When the absolute value of the steering angle θ is greater than or equal to the set value θs, that is, when it is large, it is turning left or right, and the driver's consciousness level is unlikely to decrease. The set value θs can be set, for example, in the range of 25 to 40 degrees, and good results have been obtained when the setting value θs is 40 degrees.

  Further, when it is determined that the vehicle speed V is greater than the set speed Vs and the absolute value of the steering angle θ is less than the set value θs, ON / OFF of the winker switch 13 is detected. When the winker switch 13 is in operation, it is clear that the winker switch 13 has been operated according to the driver's will, and is therefore excluded from detection targets.

  Next, in a case other than the above, that is, when the vehicle speed V is larger than the set speed Vs and the steering angle θ is smaller than the set value θs, and the turn signal switch 13 is not operated, the specific traveling that the vehicle should be the detection target is performed. Based on the determination that the vehicle is in a state (straight running state or quasi-straight running state), the driver state determination unit 20 compares the detected value of the force sensor 21 with a reference value.

  For example, among the detection axis directions of the force sensor 21, the load Fz in the steering axis direction (z direction) is compared with a reference value (Ef), and whether the load Fz is zero (or less than a minimum value) is compared. (FIG. 4). Further, the torque around the vertical axis direction (x-axis direction) orthogonal to the steering axis direction (z direction), that is, the lateral torque Tx is compared with the reference value (Et) (FIG. 5). Of course, other combinations are possible.

When the steering axial load Fz does not reach the reference value (Ef) and is not in a no-load state, or when the lateral torque Tx does not reach the reference value (Et), the normal operation state is assumed. The data for 30 seconds immediately before the axial load Fz and the lateral torque Tx is determined and stored as normal operation data (Fz ₃₀ , Tx ₃₀ ), and the reference values (Ef, Et) are updated based on the normal operation data. It is stored in the storage device 22.

These reference values (Ef, Et) can be fixed to set values that are statistically obtained through experiments. However, in the system according to the present embodiment, the set values are started as default values, and the driver is used as described above. Since it is sequentially updated based on its own operation data, more accurate determination is possible. In the embodiment, the normal operation range is up to three times the standard deviation, while the average values Fz _A and Tx _{A of} the axial load Fz and the lateral torque Tx for 2 seconds immediately before are compared with the reference values Ef and Et. When it deviates from the range, it is determined that the operation is abnormal.

  FIG. 4 is a graph showing the load Fz in the steering axis direction (z direction), and the load Fz is displayed with the direction from the force sensor 21 toward the driver being positive. The horizontal axis is time. In FIG. 4, a region 41 (hatching) where the steering axial load Fz substantially exceeds the reference value (Ef) is in an abnormal state (the driver has an excessive state where the steering axial load Fz is excessive for more than 2 seconds). It is detected that the vehicle is leaning on the steering wheel.

  The region 42 at the right end of the graph shows an abnormal state (a state in which the driver's consciousness is reduced and no force is applied to the steering wheel or a hand is released) when the steering axial load Fz is almost zero for 2 seconds or longer. Detected). In this case, not only the steering axial load Fz but also the lateral torque Tx described below may be detected together. Further, the steering axial load Fz in the normal operation state (range indicated by reference numeral 40) other than the above is used for updating the reference value (Ef).

  FIG. 5 is a graph showing the lateral torque Tx, and the horizontal axis is time. In FIG. 5, three regions 51, 52, and 53 (hatched) where the lateral torque Tx exceeds the reference value (Et) are in an abnormal state when the excessive lateral torque Tx continues for 2 seconds or more. This shows a case where it is determined that the one-handed operation state). The lateral torque Tx in a normal operation state other than the above (range indicated by reference numeral 50) is used for updating the reference value (Et).

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

  For example, in the above embodiment, the axial load Fz and the lateral torque Tx for the last 30 seconds are held as the normal operation data, but other data may be used. In the above embodiment, when the state in which the axial load Fz and the lateral torque Tx exceed the reference values continues for 2 seconds (predetermined time) or more, the abnormal operation state is determined. It is not limited to. In that case, the predetermined times of the axial load Fz and the lateral torque Tx may be different.

  In the above embodiment, the case where the abnormal operation state (dangerous operation state) is detected by using the axial load Fz and the lateral torque Tx together is shown. It is also possible to select and combine the load direction and the torque direction according to the purpose, such as configuring a system specialized for.

DESCRIPTION OF SYMBOLS 1 Steering shaft 2 Steering wheel 10 Running state discrimination | determination part 11 Vehicle speed sensor 12 Steering angle sensor 13 Winker switch 20 Driver state judgment part 21 Force sensor 22 Normal operation data storage device 23, 24 Hub 30 Attention means Fz Axial load Tx Lateral Direction torque

Claims (3)

  A multi-axis force sensor including one axis coaxially arranged with the steering shaft, and means for determining whether the driver is operating or not operating the steering wheel based on a detection value of the multi-axis force sensor. Characteristic vehicle.   A vehicle traveling state determination unit, a multi-axis force sensor including one axis coaxially arranged with the steering shaft, and a driver state determination unit, wherein the vehicle traveling state determination unit determines the specific traveling state of the vehicle The warning means is configured to operate when a specific operation or non-operation on the steering wheel of the driver determined based on the detection value of the multi-axis force sensor continues for a predetermined time or more. A vehicle driver state detection system characterized by the above. The traveling state determination unit is optimized to determine whether the vehicle is in a straight traveling state or a quasi-straight traveling state based on detection values of a vehicle speed sensor and a steering angle sensor as the specific traveling state of the vehicle. The vehicle driver state detection system according to claim 2.

Images