JP2012053746A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand a range of development for collision avoidance and warning by changing automatic constant speed travel control having a follow-up traveling control function or a collision avoidance control function according to a driver state (distracted state or the like).SOLUTION: The vehicle control device includes: setting a second threshold R0 different from a first threshold (0.5) for determining a time ratio TD/TR1 within a predetermined time TD of a feature value for driver state determination obtained by a driver state determination system; and changing follow-up traveling control of automatic constant speed travel control so as to increase an inter-vehicle distance to be set, when the time ratio TD/TR1 within the predetermined time TD of the feature value for driver state determination exceeds the second threshold R0.

Description

  The present invention relates to a vehicle control device, and more particularly, to a vehicle provided with a driver state determination system that detects a driver's state such as an indeterminate state in addition to an automatic constant speed traveling control system that controls the speed and distance between vehicles. The present invention relates to a control device.

  The vehicle is equipped with an automatic constant-speed running control system that maintains the vehicle speed set by the driver and a constant inter-vehicle distance by controlling the accelerator and brake states. In addition to the system, the driver's condition is measured to improve the accident prevention function by measuring the driver's condition and changing the control parameters of the automatic constant-speed driving control system when the driver is asleep, looking aside, or sloppy There is a thing equipped with.

Japanese Unexamined Patent Publication No. 2009-23481 Japanese Patent No. 4333797

The vehicle control device according to Patent Document 1 includes line-of-sight detection means for detecting the line-of-sight direction of the driver, and the driver recognizes the preceding vehicle when traveling following the preceding vehicle at a predetermined inter-vehicle distance. If not, the distance is changed to increase the inter-vehicle distance.
The vehicle control device according to Patent Document 2 determines whether or not the actual concentration degree of the driver is insufficient in terms of preventing accidents, and is changed so that the vehicle travels at a control vehicle speed lower than the set vehicle speed. To do.

By the way, in the driver state determination system according to Patent Documents 1 and 2, it is assumed that the driver state can be estimated at an arbitrary time. In the case of estimation, etc., it took a certain time to estimate the driver state.
For example, as a driver status determination system, the driver status is stochastically estimated from the driver features and changes within a certain time, and the status is detected when the probability exceeds a certain threshold. Some output signals that
However, when such a driver state determination system is used, the predetermined first time is the minimum required from the time when the driver enters the sloppy state until the sloppy state is actually detected. Required a maximum second time much longer than this first time.
In the case of an automatic constant speed traveling control system to which such a driver state determination system is added, the driver state detection by the driver state determination system may be delayed from the alarm by the automatic constant speed traveling control system. There is a disadvantage that the effectiveness of the state determination system is greatly reduced.

  Therefore, the object of the present invention is to change the automatic constant speed traveling control with the following traveling control function or the collision avoidance control function according to the driver's condition, thereby expanding the range up to the collision avoidance and warning. The object of the present invention is to provide a vehicle control device that can increase the effectiveness of driver state determination control by using the probabilities of driver state determination in advance, and can improve the practicality by both of them.

  The present invention includes a radar for detecting an obstacle, constant speed traveling control for converging and maintaining the actual vehicle speed at a set speed, and tracking for following a preceding vehicle so as to maintain a set inter-vehicle distance based on the detection of the obstacle. An automatic constant speed traveling control system including an automatic cruise control device that performs automatic constant speed traveling control that performs traveling control and warning control that issues an approach warning when an obstacle is closer than the set inter-vehicle distance is provided, The state of the driver who drives the vehicle is determined based on the comparison with the first threshold for the time ratio within the predetermined time of the characteristic value for determining the driver state, and the generation of the alarm based on the determination to affirm the casual state and the driving In a vehicle control device provided with a driver state determination system that enables output of a time ratio within a predetermined time of a characteristic value for driver state determination, the characteristic value for driver state is obtained by the driver state determination system. In addition, a second threshold different from the first threshold for determining the time ratio within the predetermined time of the driver state determination feature value is set, and the time ratio within the predetermined time of the driver state determination feature value Is changed so as to increase the set inter-vehicle distance in the following traveling control of the automatic constant speed traveling control.

  The vehicle control device of the present invention can be applied to collision avoidance and warnings by changing the automatic constant speed travel control provided with the following travel control function or the collision avoidance control function according to the driver state. In addition, the effectiveness of the driver state determination control can be improved by using the probability of the driver state determination in advance, and further, the practicality can be improved by both of them.

FIG. 1 is a system configuration diagram of a vehicle control apparatus. (Example) FIG. 2 is a flowchart of the vague state processing of the vehicle. (Example) FIG. 3 is a flowchart of automatic constant speed traveling control of the vehicle. (Example) FIG. 4 is a time chart of the control at the time of approach warning. (Example)

  The present invention provides a wide range of developments up to collision avoidance and warning, increases the effectiveness of driver state determination control by using the probability of prior driver state determination, and increases the practicality by combining both The object is achieved by changing the automatic constant speed traveling control provided with the following traveling control function or the collision avoidance control function according to the driver state.

1 to 4 show an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a vehicle control device mounted on a vehicle having an engine and a transmission. The vehicle control device 1 is a system that performs combined vehicle control such as automatic constant speed traveling control, tracking traveling control, obstacle detection or collision avoidance control, and driver state determination control, or integrated control. In a vehicle that detects objects and performs automatic constant speed running control with a follow-up running control function or collision avoidance control function, it detects the state of the driving driver and follows the running control function based on the detected state of the driver. Alternatively, it performs composite control or integrated control of a vehicle that performs automatic constant speed traveling control having a collision avoidance control function.
For this reason, the vehicle control device 1 is provided with an image processing system 2, a driver state determination system 3, and an automatic constant speed traveling control system (auto cruise system) 4.

The image processing system 2 includes an image processing device (image processing unit) 5. The image processing device 5 is in communication with a CCD camera 6 as an imaging means for imaging a driver's mood state and a near infrared LED 7 that irradiates the driver's face. The near-infrared LED 7 is, for example, a first near-infrared LED (LED1) very close to the CCD camera 6 and a first near-infrared LED (LED2) at a distance from the CCD camera 6 in order to reliably detect the driver's pupil. ).
The image processing device 5 detects the nostril, detects the pupil, detects the cornea reflection, and detects the pupil area and the face direction by contacting the first detection unit 8. Second detection means 9 to perform and LED light emission timing means 10 communicated with the near-infrared LED 7 are provided.

The driver state determination system 3 includes a driver state detection device (driver state detection unit) 11.
The driver state detection device 11 includes a calculation unit 12 that calculates a pupil area reduction rate and a determination reference area, a casual state determination processing unit 13 that communicates with the calculation unit 12, and a casual state determination processing unit 13. And a driver state determination means 14 in contact with the vehicle.
The calculation means 12 is in contact with the second detection means 9 of the image processing apparatus 5.

The automatic constant speed traveling control system 4 includes an auto cruise control device (auto cruise control unit) 15.
The auto cruise control device 15 includes, on the input side, a radar 16 provided at the front of the vehicle for detecting an obstacle ahead, a vehicle speed sensor 17 for detecting the speed of the vehicle, and a steering sensor 18 for detecting a steering angle. And a yaw rate sensor 19 for detecting the turning state of the vehicle, and on the output side, a throttle control device 20 and an automatic braking (braking) device 21 are in communication.
The auto-cruise controller 15 determines the approaching vehicle, calculates the relative speed / acceleration, the determination calculation means 22 for calculating the collision time, and contacts the determination calculation means 22 to determine the approach degree of the preceding vehicle. Degree determination means 23.
A radar 16, a vehicle speed sensor 17, a steering sensor 18, and a yaw rate sensor 19 communicate with the determination calculation means 22.
The throttle control device 20 and the automatic braking device 21 are in communication with the preceding vehicle approach degree determination means 23.
In addition, the preceding vehicle approaching degree determining means 23 is in communication with the rough state determining processing means 13 and the driver state determining means 14 of the driver state detecting device 11.
Further, a speaker 24 and a steering vibration device 25 are provided between the preceding vehicle approach degree determination means 23 and the driver state determination means 14 so as to constitute an alarm means.

In the automatic cruise control device 15 of the automatic constant speed travel control system 4, constant speed travel control (cruise control) for converging and maintaining the actual vehicle speed at the set speed and preceding distance to maintain the set inter-vehicle distance based on the detection of the obstacle. Basic automatic constant speed travel control (auto cruise control) is performed in which follow-up running control that follows a vehicle and warning control that issues an approach warning when an obstacle is closer than the set inter-vehicle distance.
In this automatic constant speed running control, the presence or absence of a preceding vehicle (approaching vehicle) is determined by the radar 16 that detects an obstacle, and the selected inter-vehicle distance and the set inter-vehicle distance are ensured. Feedback control. At this time, acceleration / deceleration of the vehicle is automatically performed by engine output torque control. The transmission is fixed at a constant speed (cruise) gear (speed ratio) (usually at the highest speed or the minimum gear ratio) or by selecting a dedicated gear map. Shift control within a specific range.
In addition, the automatic constant speed traveling control system 4 can also perform collision avoidance control in which automatic braking (braking) is performed based on detection of an obstacle.
Further, the auto-cruise control device 15 compares the collision time (TC) calculated based on the detection of the obstacle and the inter-vehicle time indicating the degree of danger, and when it is determined to be necessary, the collision avoidance that can perform automatic braking. Take control.
The collision time (TC) is calculated from the inter-vehicle distance between the preceding vehicle serving as an obstacle and the own vehicle, the relative speed between the preceding vehicle serving as an obstacle and the own vehicle, and the relative acceleration.
Instead of the above-described collision time (TC), an inter-vehicle distance may be calculated and determined by another set inter-vehicle distance shorter than the set inter-vehicle distance. Moreover, as said approach degree determination, you may calculate an approach degree from the relative speed or relative acceleration of the preceding vehicle used as an obstruction, and the own vehicle.

In the driver state detection device 11 of the driver state determination system 3, the state of the driver driving the vehicle is determined based on the characteristic value for driver state determination (the pupil area reduction rate (RR) during a certain time (TR1) is a reference value. Based on a determination that the time ratio (TD / TR1) within a predetermined time (TD) in a state exceeding (A1)) is based on a comparison with the first threshold value (0.5), and an affirmative state is affirmed It is possible to output to the automatic constant speed traveling control system 4 the time ratio (TD / TR1) within the predetermined time (TR1) of the generation of the alarm and the characteristic value for determining the driver state.
The driver state determination by the driver state detection device 11 may require some initial setting time before actual determination is started.

In this embodiment, the vehicle control apparatus 1 determines the time ratio (TD / TR1) within the predetermined time (TD) of the driver state determination feature value obtained by the driver state determination system 3. A second threshold (R0) different from the first threshold (0.5) is set, and the time ratio (TD / TR1) within the predetermined time (TD) of the driver state determination feature value is the second threshold. When exceeding (R0), it changes so that the said setting inter-vehicle distance in the following driving | running | working control of automatic constant speed driving control may be increased.
In this way, by changing the inter-vehicle distance according to the driver's condition, it is possible to secure a response time suitable for the driver's condition, thereby preventing collision and reducing damage. In addition, it is possible to make a rough determination before issuing a warning by an approach warning, to perform an appropriate warning, and to prevent a collision and reduce damage. Furthermore, since it is possible to eliminate the setting for issuing an alarm before the determination of the driver's condition, the troublesomeness caused by an inappropriate alarm can be eliminated.
In other words, in the vehicle control device 1 that performs an alarm or automatic braking when the possibility of a collision with a preceding vehicle or the like increases, it is effective for a system that requires a certain amount of time for the driver state determination system 3 to determine a random state. Can increase the sex.

In the vehicle control device 1, a first threshold value (TD / TR 1) for determining a time ratio (TD / TR 1) within a predetermined time (TD) of the driver state determination feature value obtained by the driver state determination system 3. 0.5) and a third threshold value (0) smaller than the second threshold value (R0) is set. In this case, the automatic constant speed traveling control compares the time ratio (TD / TR1) within the predetermined time (TD) of the driver state determination feature value with the third threshold (0) when performing the warning control. When the result is judged to be in a more sloppy state than in the case where there is no sloppy state, the alarm level at the speaker 24 or the like is changed to be increased.
Thus, the warning can be appropriately changed according to the driver's condition, and the effect of preventing the collision and reducing the damage can be improved.

Next, the control of the vehicle according to this embodiment will be described based on the flowcharts of FIGS.
First, the casual state process of FIG. 2 will be described.
As shown in FIG. 2, when the program is started (step A01), a face image is taken (step A02), the pupil area is calculated (step A03), and the pupil area reduction rate (RR) is calculated (step A04). Then, the predetermined time (TD) of the driver state determination feature value (RR> A1 (reference value of the pupil area reduction rate)) is calculated in the latest fixed time (TR1) (step A05).
Then, it is determined whether or not the time ratio (TD / TR1)> first threshold (0.5) (step A06).
If this step A06 is YES, a warning for detection of a sloppy state is output to the speaker 24 or the like (step A07).
After step A07 or when step A06 is NO, the time ratio (TD / TR1) is output to the preceding vehicle approach degree determining means 23 (step A08), and the program is returned (step A09). .

Next, the automatic constant speed traveling control of FIG. 3 will be described.
As shown in FIG. 3, when the program starts (step B01), sensor information is acquired (step B02), a preceding vehicle is selected (step B03), and a collision time (TC) is calculated (step B04).
Then, it is determined whether or not the time ratio (TD / TR1) ≠ third threshold (0), that is, the possibility that the driver is in a vague state (step B05).
If this step B05 is YES, it is possible that the driver may be in a random state, and it is determined whether the degree of approach to the preceding vehicle is large in the determination of the collision time (TC) (step B06). If step B06 is NO, it is determined whether the time ratio (TD / TR1)> second threshold (R0) (step B07). If this step B07 is YES, automatic constant speed running control is performed. The inter-vehicle distance is controlled so as to increase the set inter-vehicle distance in the following traveling control (step B08), and then the program is returned (step B09).
If step B06 is YES, a warning is issued with a loud sound as an approach warning for the preceding vehicle (step B10).
After the process of step B10, or when step B07 is NO, the program is returned (step B09).
On the other hand, when step B05 is NO, it is determined whether or not the driver is not in a random state and the degree of approach to the preceding vehicle is large in the determination of the collision time (TC) (step B11). If YES, a normal approach warning is given (step B12), and then the program is returned (step B09).
However, if step B11 is NO, the program is immediately returned (step B09).

The control of the vehicle in the flowcharts of FIGS. 2 and 3 will be described in more detail, including the time chart of FIG.
When determining the time ratio (TD / TR1) with the first threshold value (0.5), as shown in FIG. 4, the shortest time (T1) for determining that the state is in a random state is T1 = TR1 / 2. (= 0.5 × TR1), and there is a variation in time so that T2 = TR1 in the longest time (T2) in which it is determined that the state is indiscriminate.
The fixed time (TR1) determines the longest time T2 (for example, 5 seconds) as the upper limit time for determination at a time, but the increase from the measurement start time T0 to the time T2 is repeated, and the measurement target The value varies depending on the state.
For example, when TR1 = T2 is 5 seconds, which is the longest time T2, the predetermined time (TD) corresponding to the first threshold (0.5) is 2.5 seconds. This predetermined time (TD) is the time during which the pupil area reduction rate (RR) exceeds the reference value (A1) during the measurement time of the fixed time (TR1). Since TD ≦ TR1, TR1 = In the period up to 5 seconds, the pupil area reduction rate (RR) exceeds the reference value (A1) for TD = 2.5 seconds (or more). That is, the maximum time of the predetermined time (TD) is determined as 2.5 seconds (or more). Conversely, if TD = 2.5 seconds (or more), the determination can be made without waiting until TR1 = 5 seconds.
That is, as shown in FIG. 4, if the elapsed time from the start of measurement for a certain time (TR1) and the measurement time for the predetermined time (TD) are the same, TR1 = TD, which is TD = 2.5 seconds ( If this is the case, determination of time ratio (TD / TR1)> first threshold (0.5) may be affirmed without waiting for TR1 = 5 seconds. In this case, T1 = TR1 / 2 (= 0.5 × TR1). In this way, the fixed time (TR1) varies between the shortest time T1 and the longest time T2.
In addition, the driver is in a state of a boundary between the arousal state and the sloppy state, and in particular, if the driver is in a state close to awakening among the states determined to be sloppy, the certain time (TR1) required for determination tends to be the longest. Become. In the function of the system according to this embodiment, the determination frequency in this case is high and is the most important time.

The vehicle control according to this embodiment will be described more specifically below.
A driver's face image is acquired by the CCD camera 6. In order to detect the driver state at night, the driver's face is irradiated with an invisible near-infrared LED 7. In order to reliably detect the driver's pupil using the red-eye phenomenon, the near-infrared LED 7 is installed in two places, very close to the CCD camera 6 (LED 1) and a little apart (LED 2), and alternately emits pulses. Let The timing of light emission is synchronized with each field of the CCD camera 6 by the LED light emission timing means 10, for example, the LED 1 is lit in the even field and the LED 2 is lit in the odd field.
In the image processing device 5, when the even-odd field difference is taken, an image in which only the pupil remains clearly can be obtained. The pupil area and the like are measured from the acquired image.
The pupil area data is output to the calculation means 12 of the driver state detection device 11 and compared with the typical value of the pupil area before a certain time. If the pupil area reduction rate (RR) exceeds the reference value (A1), it is determined that there is a possibility that the driver has entered a state of ambiguity.
The processing for determining the sloppy state is based on a criterion for determining that the driver is in a sloppy state, for example, the pupil area reduction rate (RR) exceeds the reference value (A1) from the present to a certain time (TR1) before. It is set that the time ratio (TD / TR1) exceeds half.

As shown in FIG. 4, when the driver enters a sloppy state at time T0 and then continues to be sloppy, it is determined that the driver is in a sloppy state.
The shortest time T1 is T1 = TR1 / 2, and the longest time T2 is T2 = TR1.
For example, when considering a case where the vehicle is traveling between a preceding vehicle and a certain vehicle by automatic constant speed traveling control, it is assumed that the preceding vehicle starts sudden deceleration at time T0 and the driver is in a sloppy state at the same time. The driver cannot recognize the change of the preceding vehicle, the degree of approach becomes large, and an approach warning is issued by the automatic constant speed traveling control system at time T3. Since the driver is awakened by this warning, if T3 <T1, the driver state detection device 11 does not play any role. Moreover, when T1 <T3 <T2, the case where the driver state detection device 11 does not function occurs, and the effectiveness of the driver state detection device 11 is reduced.
Therefore, the driver state detection device 11 detects the possibility of a sparse state, and at the stage where the sloppy state determination process is performed, the pupil area reduction rate (RR) with respect to a certain time (TR1) is the reference value (A1). When the time ratio (TD / TR1) exceeds the first threshold (0.5), the throttle is set to increase the inter-vehicle distance according to the size of the time ratio (TD / TR1). The control device 20 and / or the automatic braking device 21 are controlled.
The inter-vehicle distance to be controlled does not need to be set unnecessarily long. For example, as shown in FIG. 4, when the preceding vehicle suddenly brakes at time T1, it is determined that the driver is in a loose state at time T2. When the warning is issued, the necessary inter-vehicle distance D1 at time T1 is V, the vehicle traveling speed set by the auto-cruise control device 15 is automatically set by the deceleration of the preceding vehicle and the automatic constant-speed traveling control of the vehicle. When the acceleration of the difference in deceleration is A and the safe inter-vehicle time considering the driver's reaction time is defined as TS,
D1 = V (T2-T1) + TS × (T2-T1) ² × A / 2
As a result, at least after the time T1, there is a high possibility of preventing a collision accident due to a delay in the reaction time caused by the driver being in a state of disorder.

In the control of the inter-vehicle distance as described above, on the time chart of FIG. 4, the time T3 is changed by the control so that T3 <T1 is changed to T3> T1, or T1 This corresponds to making T3> T2 in the case of <T3 <T2.
In the casual state, the response time to the alarm increases, and in the normal automatic constant speed traveling control, there is a high possibility of causing a collision accident, whereas in the system according to this embodiment, by controlling the inter-vehicle distance, The timing at which an approach warning is issued by the constant-speed traveling control system 4 is delayed, and the driver is awakened by a warning of a vague state by the driver state detection device 11, so that a great effect can be obtained in preventing an accident.
In addition, if a warning sound or the like is output at a stage where it is not determined that the state is in a messy state, the driver may feel annoyed if the state is not in a sloppy state. However, in the system according to this embodiment, the inter-vehicle distance is gradually reduced. Since the change is made, there is an effect that it is difficult to feel annoyance.
Further, in the situation where an approach warning is issued by the automatic constant speed traveling control system 4, when the driver state detection device 11 is performing the driver's casual state determination process, the approach warning is determined depending on the time ratio (TD / TR1). Increase the short sound.
As a result, if the driver is in an ambiguous state, the driver can be quickly returned to the awakening state with a larger warning sound, so that an accident prevention effect can be obtained.
As a result, according to this embodiment, before the driver state determination is made, the driver state is determined by controlling the inter-vehicle distance in consideration of both the state of the driver state process and the possibility of collision. In addition, it is possible to improve the accident prevention function when the automatic constant speed traveling function is used in a system that requires a certain time.

  In the present invention, the speed control is performed so as to converge to the target speed set by the throttle control. However, the continuously variable transmission (CVT or the like) is provided to perform the throttle control and the gear ratio control. It is also possible to perform cooperative control.

  The control device of the present invention can be applied to various vehicles.

DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus 2 Image processing system 3 Driver state determination system 4 Automatic constant speed driving control system 5 Image processing apparatus 6 CCD camera 11 Driver state detection apparatus 14 Driver state determination means 15 Auto cruise control apparatus 16 Radar 20 Throttle Control device 21 Automatic braking device 23 Advance vehicle approach degree determination means

Claims (2)

  A constant speed traveling control that includes a radar that detects an obstacle, converges and maintains the actual vehicle speed at a set speed, and a following traveling control that follows a preceding vehicle so as to maintain a set inter-vehicle distance based on the detection of the obstacle, Driving to drive a vehicle by providing an automatic constant speed traveling control system including an automatic cruise control device that performs automatic constant speed traveling control that performs warning control that issues an approach warning when approaching an obstacle than the set inter-vehicle distance For determining the driver's state based on the comparison with the first threshold for the time ratio within the predetermined time of the characteristic value for determining the driver's state, and for generating the alarm based on the determination to affirm the casual state and for determining the driver's state In the vehicle control device provided with the driver state determination system that enables output of the time ratio within the predetermined time of the feature value, the driving obtained by the driver state determination system A second threshold value different from the first threshold value for determining the time ratio within the predetermined time of the state determination feature value is set, and the time ratio within the predetermined time of the driver state determination feature value is the second threshold value. When the vehicle threshold is exceeded, the vehicle control device is changed so as to increase the set inter-vehicle distance in the follow-up travel control of the automatic constant speed travel control.   A first threshold value for determining a time ratio within a predetermined time of the driver condition determination feature value obtained by the driver condition determination system and a third threshold value smaller than the second threshold value are set automatically. The constant speed traveling control is based on a determination based on a comparison result between the time ratio within the predetermined time of the driver state determination feature value and the third threshold value when performing the warning control, as compared with the case where there is no indiscriminate state. The vehicle control device according to claim 1, wherein when there is a vague state, the alarm level is changed to increase.

Images