JP5114903B2 - Vehicle driving support device - Google Patents

Description

  The present invention relates to a driving support device that supports a driver's driving operation during a curve run.

  When there are multiple curves in front of the vehicle, an alarm is given only when entering the first curve, and in principle no alarm is given after the second curve, but when the second curve is a hairpin curve There is known a driving support device that performs an alarm (see, for example, Patent Document 1).

Prior art documents related to the invention of this application include the following.
Japanese Patent No. 3161264

However, in the conventional driving support apparatus described above, the curves are divided according to the distance between the curves, so when passing through a plurality of curves at a high speed, the first curve is changed to the second curve in a short time. Even if the warning is not required for the second curve, if the distance between the first curve and the second curve is greater than the threshold, it is determined that the curve is not a continuous curve, There is a problem that an alarm is given even when entering.
In addition, when the second curve following the first curve is a hairpin curve, an alarm is given when entering the second curve. There is a problem that a necessary alarm is not made.

The driving support apparatus according to the present invention includes a road information detecting unit that detects information on a current position of a vehicle and a curve ahead of the vehicle, a vehicle state detecting unit that detects a current vehicle state, the current position of the vehicle, the vehicle Based on the forward curve information and the current vehicle state, vehicle state estimation means for estimating the vehicle state when passing the vehicle forward curve, and vehicle state storage for storing the vehicle state detected by the vehicle state detection means when passing the curve Means, a permissible vehicle state estimating means for estimating a permissible vehicle state when the driver passes the curve based on a past vehicle state when the vehicle has passed the curve stored in the vehicle state storage means, and the vehicle forward curve passing Assistance operation determining means for determining whether or not to perform driving support on a curve based on an estimated vehicle state at the time and an allowable vehicle state when the driver passes the curve; A driving support device wherein the support operation determination means, when the estimated vehicle state difference between the allowable vehicle state is within a predetermined range, the estimated vehicle state small difference between the allowable vehicle state It is determined that the driving assistance is performed when the value representing the estimated vehicle state becomes large .

  According to the present invention, driving assistance can be reliably performed only when necessary.

  FIG. 1 shows the configuration of an embodiment. The driving support controller 1 includes a microcomputer (not shown), a memory, an A / D converter, and the like, and includes control blocks 1a to 1d configured by a software form of the microcomputer. In the control block 1a, the vehicle state when passing the forward curve is estimated, and in the control block 1b, the storage of the vehicle state when passing the curve and the allowable vehicle state of the driver are calculated. Here, the vehicle state when passing the curve is a physical quantity related to the difficulty of passing the curve. Further, based on the estimated vehicle state at the time of passing through the forward curve and the allowable vehicle state of the driver, the control block 1c makes an alarm determination to the driver, and the control block 1d makes an operation determination of deceleration control.

  The navigation device 2 includes a GPS receiver and a road map data storage device (not shown), detects the current position of the vehicle, outputs the current position and surrounding road information, and displays a plurality of curves existing on the forward travel route. Detect and output information such as the position of each curve, radius of curvature, and the distance between curves. The vehicle sensor 3 includes various sensors for detecting a vehicle state, a vehicle speed sensor, a yaw rate sensor, a steering angle sensor, an accelerator opening sensor, and the like. The voice output device 4 outputs various voice guidances and warnings according to voice commands of the driving support controller 1. The brake control device 5 controls the brake fluid pressure in accordance with the brake operation command from the driving support controller 1.

  Here, the vehicle state when passing the curve includes vehicle behavior detected by the vehicle sensor 3, such as lateral acceleration detected by the lateral G sensor, yaw rate detected by the yaw rate sensor, and driving operation state of the driver, such as a steering angle sensor. There are a steering angle, a steering angular velocity, and the like detected by.

  Next, detailed operations of the control blocks 1a to 1d of the driving support controller 1 will be described. In the control block 1a, the vehicle position from the navigation device 1 and its surrounding road information and the curve information ahead of the vehicle are obtained, the vehicle state is obtained from the vehicle sensor 3, and the vehicle state when passing the forward curve is estimated. In the control block 1b, the vehicle state of the currently passing curve is detected and stored based on the vehicle position of the navigation device 1 and the road information around it, the curve information in front of the vehicle, and the vehicle state of the vehicle sensor 3. . The memory (not shown) of the driving support controller 1 stores the vehicle state of the curve that has passed in the past for each curve. In the control block 1b, the maximum value is extracted as the allowable vehicle state of the driver from the vehicle states of the curves that have passed in the past.

  Whether the control block 1c warns that the vehicle state when passing the forward curve may exceed the allowable vehicle state of the driver based on the estimated vehicle state when passing the forward curve and the allowable vehicle state of the driver When a warning is issued, the voice command of the warning message is output to the voice output device 4. In the control block 1d, based on the estimated vehicle state at the time of passing the forward curve and the allowable vehicle state of the driver, whether to perform the brake control so that the vehicle state when passing the forward curve does not exceed the allowable vehicle state of the driver If the brake control is performed, a brake operation command is output to the brake control device 5.

  FIG. 2 is a flowchart showing a vehicle state estimation process at the time of passing a forward curve, which is executed in the control block 1a. Here, it is assumed that there are curves at N locations ahead of the vehicle, and the number of each curve is represented by i (i = 1, 2,..., N, initial value is 0). Further, the lateral acceleration (lateral G) when passing the curve will be described as an example of the vehicle state when passing the curve.

In step 1, 1 is added to the curve number i. In the subsequent step 2, the inlet speed v_i of the i-th curve is predicted. Here, it is assumed that the driver performs a deceleration operation at a predetermined deceleration a after T seconds from the time when the warning is given to the driver from the audio output device 4.
v_i = sqrt {v ² −2 · a · (d_i−v · T)} (1)
In equation (1), v is the current vehicle speed detected by a vehicle speed sensor (not shown), and d_i is the distance to the i-th curve.

In step 3, the lateral acceleration yg_i generated when passing through the i-th curve is predicted by the following equation.
yg_i = v_i ² / R_i (2)
In the equation (2), R_i is the radius of curvature of the i-th curve.

  In step 4, a correction coefficient corresponding to the traveling environment and the traveling state is obtained. This correction coefficient is set in advance to be a small value when it is predicted that the curve passage is easy, and to a large value when the curve passage is predicted to be difficult. For example, the correction coefficient c_road_width corresponding to the road width is set to a smaller value as the road width is larger as shown in FIG. The correction coefficient c_road_type corresponding to the road type is set to a small value for a highway and a large value for a narrow street. The correction coefficient c_vk corresponding to the vehicle speed is set to a larger value as the vehicle speed is higher.

  In addition, the correction coefficient according to the difficulty of passing through the curve detects the weather, road surface condition, good visibility ahead of the curve, lateral road gradient (kant), vertical road gradient (up and down), You may employ | adopt the correction coefficient determined according to those values.

The lateral acceleration yg_i when passing through the i-th curve is corrected using the obtained correction coefficient to obtain a vehicle state a_i when passing through the curve.
a_i = c_road_width · c_road_type · c_vk · yg_i (3)

Note that the vehicle state when passing the curve is not limited to the lateral acceleration yg_i. For example, the yaw rate yawrate_i at the time of passing through the i-th curve may be obtained by the following equation to obtain the vehicle state at the time of passing through the curve.
yawrate_i = v_i / R_i (4)
Further, the steering angle str_ang_i at the time of passing through the i-th curve may be obtained, and the vehicle state at the time of passing through the curve may be obtained.
str_ang_i = Lw · Ns · (1 + A · v ² ) · yawrate_i / v (5)
In equation (5), Lw is the wheelbase length of the vehicle, Ns is the steering angle ratio, and A is the stability factor. Furthermore, the steering angular velocity str_spd_i when passing through the i-th curve may be obtained to obtain the vehicle state when passing through the curve.
Tk = 2 · (d_i−d_i−1) / (v_i−v_i−1)
str_spd_i = (str_ang_i−str_ang_i−1) / Tk (6)

In step 5, it is confirmed whether or not the vehicle state estimation calculation at the time of passing the curve is completed for all N curves. If not completed, the process returns to step 1 and repeats the above-described processing. Then go to step 6. In step 6, the maximum value is retrieved from the vehicle state (here, lateral acceleration yg_i) at the time of passing N curves in front of the vehicle, and set as the estimated vehicle state a when passing the forward curve.
a = max (a_1, a_2, a_3, ..., a_N) (7)

  FIG. 3 is a flowchart showing a vehicle state storage process and a driver-permitted vehicle state calculation process when passing a curve, which are executed in the control block 1b. In step 11, it is determined whether or not the vehicle is passing the current curve based on information such as the current location obtained from the navigation device 2. When it is passing through the curve, the process proceeds to step 12, and when it is not passing through the curve, the process proceeds to step 16.

In step 12, the lateral acceleration generated while passing the curve is detected by a lateral G sensor (not shown) and is set as the lateral acceleration yg_0 of the passing curve. In the following step 13, the lateral acceleration yg_0 of the passing curve is corrected using the correction coefficients c_road_width, c_road_type, and c_vk described above to obtain the vehicle state b_0 of the passing curve.
b_0 = c_road_width · c_road_type · c_vk · yg — 0 (8)

  In addition to the lateral acceleration yg_0, the vehicle state b_0 of the passing curve can be obtained based on at least one of the yaw rate yawrate_0, the steering angle str_ang_0, and the steering angular velocity str_spd_0 detected by the vehicle sensor 3.

In step 14, it is confirmed whether or not the vehicle has passed the curve. When the vehicle is passing, the process returns to step 12 to repeat the above-described processing. In step 15, the vehicle state b_0 of the curve that has passed is stored as the vehicle state b_1 of the curve that has passed in the past.
b_1 = b_0 (9)
In addition, together with the vehicle state b_1 at the time of past curve passing, the passing date and time of the curve are stored together.

Here, the total number of vehicle states at the time of passing past stored curves is M, and each stored vehicle state is number i (i = 1, 2,..., M, initial value is 0). To express. 1 is added to the vehicle state number i stored in step 16, and the vehicle state b_i in the past curve storage stored in step 17 is corrected with a correction coefficient c_time based on the elapsed time from the curve passage date and time.
b_i ′ = c_time · b_i (10)
FIG. 5 shows an example of the correction coefficient c_time based on the elapsed time from the curve passage date and time.

  The correction of the vehicle state b_i when passing the past curve is not limited to the correction based on the elapsed time, and the vehicle state b_i when passing the past curve becomes smaller as the distance between the curve and the curve is longer. May be. Alternatively, a history of the vehicle speed may be stored, and the vehicle speed may be corrected to a smaller value once the vehicle speed becomes zero.

In step 18, it is confirmed whether or not the correction by the elapsed time c_time has been completed for all the M past vehicle states b_i. If not, the process returns to step 16 to continue the correction process. If the correction for the vehicle state b_i at the time of passing through all the M past curves is completed, the process proceeds to step 19, and the maximum value in the vehicle state b_i at the time of passing through the past curve after the correction is set as the allowable vehicle state b of the driver To do.
b = max (b_1, b_2,..., b_M) (11)

Next, warning determination to the driver executed in the control block 1c will be described. In this embodiment, warning determination to the driver is performed using the determination map shown in FIG. In FIG. 6, the reference value c1 of the driver-permitted vehicle state when passing the curve is a vehicle state stored in advance in the driving support controller 1, and is set to, for example, 3.0 m / s ² when the vehicle state is lateral acceleration. .

  The estimated vehicle state (estimated lateral acceleration) a when passing the forward curve is larger than the driver-acceptable vehicle state (allowable lateral acceleration) b when passing the curve, and the larger the amount (ab), the estimated when passing the forward curve. An alarm is issued in a state where the vehicle state (estimated lateral acceleration) a is small. Conversely, as the estimated vehicle state (estimated lateral acceleration) a when passing the forward curve is smaller than the driver allowable vehicle state (allowable lateral acceleration) b when passing the curve, the estimated vehicle state (estimated lateral acceleration) when passing the forward curve. ) An alarm is issued when a is large. If the amount (ab) that increases the allowable value b of the estimated value a exceeds x1 (for example, 0.1 G), an alarm is issued when the estimated value a is greater than or equal to the reference value c1.

  As a specific form of alarm, for example, for the first curve, the voice output device 4 broadcasts “It is a curve”, and while passing through the first curve, for the second curve ahead When an alarm is issued or when an alarm is issued for the second and subsequent curves, the audio output device 4 broadcasts “curve continues”.

Next, the operation determination of the deceleration control executed in the control block 1d will be described. In this embodiment, the operation determination of the deceleration control is performed using the determination map shown in FIG. In FIG. 7, the reference value c2 of the driver-permitted vehicle state at the time of passing through the curve is a vehicle state stored in advance in the driving support controller 1 and is, for example, 4.0 m / s ² when the vehicle state is lateral acceleration. .

  The estimated vehicle state (estimated lateral acceleration) a when passing the forward curve is larger than the driver-acceptable vehicle state (allowable lateral acceleration) b when passing the curve, and the larger the amount (ab), the estimated when passing the forward curve. Deceleration control is performed in a state where the vehicle state (estimated lateral acceleration) a is small. Conversely, as the estimated vehicle state (estimated lateral acceleration) a when passing the forward curve is smaller than the driver allowable vehicle state (allowable lateral acceleration) b when passing the curve, the estimated vehicle state (estimated lateral acceleration) when passing the forward curve. ) Deceleration control is performed with a being large. If the amount (ab) that increases the allowable value b of the estimated value a exceeds x1 (for example, 0.1 G), an alarm is issued when the estimated value a is greater than or equal to the reference value c2.

  By making the operation determination threshold value of this deceleration control larger than the alarm determination threshold value for the driver (see FIG. 6), the deceleration control is operated after the driver's alarm. When entering the deceleration control operation region of the operation determination map shown in FIG. 7, a brake operation command is output to the brake control device 5.

  As shown in FIG. 8, when the lateral acceleration (lateral G) generated in the past in the curve run is 0.3 G and the estimated lateral G in the previous curve is 0.3 G, no alarm is given. As shown in the figure, when the lateral G generated in the curve run in the past is 0.3 G and the estimated lateral G in the previous curve is 0.4 G, an alarm is issued. In other words, it is possible to suppress the alarm in a situation where the driver judges that it is not overspeed and is traveling on a curve, and can issue an alarm when there is a steep curve ahead.

  As described above, according to one embodiment, the vehicle state at the time of passing the vehicle forward curve is estimated based on the current position of the vehicle, the curve information ahead of the vehicle, and the current vehicle state, and stored in the past. Based on the vehicle state at the time of passing the vehicle's curve, the driver's allowable vehicle state at the time of passing the curve is estimated. Since it is determined whether or not driving assistance is performed, unnecessary driving assistance is prevented and driving assistance can be reliably performed only when necessary.

  In one embodiment, the estimated vehicle state when passing the vehicle forward curve and the allowable vehicle state when the driver passes the curve are corrected according to the driving environment and the driving state of the vehicle. The state can be estimated.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the navigation device 2 constitutes road information detection means, the vehicle sensor 3 constitutes vehicle state detection means, and the driving support controller 1 constitutes vehicle state estimation means, allowable vehicle state estimation means, and support operation determination means. The above description is merely an example, and when interpreting the invention, the correspondence between the items described in the above embodiment and the items described in the claims is not limited or restricted.

  In the above-described embodiment, the estimated vehicle state a_i at the time of passing through the forward curve is determined based on the road width, road type, vehicle speed, weather, road surface condition, good visibility of the curve destination, lateral road gradient (cant), vertical The vehicle state b_i at the time of passing the curve is corrected to the elapsed time, the distance between the curve and the curve, the traveling environment such as the vehicle speed and the traveling state, and corrected according to the traveling environment such as the road gradient (up and down) of the direction. Although the example which correct | amends according to it was demonstrated, correction | amendment of a vehicle state is not limited to the driving | running environment and driving state which were mentioned above.

  Further, instead of correcting the vehicle state according to the traveling environment and traveling state of the vehicle, the alarm determination threshold shown in FIG. 6 and the deceleration control operation determination threshold shown in FIG. It may be corrected according to the above. FIG. 10 shows an example in which the alarm determination threshold value is corrected according to the vehicle speed, and FIG. 11 shows an example in which the alarm determination threshold value is corrected in accordance with the elapsed time from the curve passing time.

  Furthermore, in the above-described embodiment, the lateral acceleration, yaw rate, steering angle, and steering angular velocity are described as examples of the vehicle state that represents the difficulty level of passing the curve. However, the vehicle state that represents the difficulty level of passing the curve is described above. However, the present invention is not limited to the embodiment. Moreover, it is good also as a vehicle state showing the difficulty of a curve passage combining several vehicle states.

The figure which shows the structure of one embodiment Flowchart showing vehicle state estimation operation when passing vehicle forward curve Flowchart showing storage of vehicle state when passing curve and operation for estimating allowable vehicle state when passing curve of driver The figure which shows the correction coefficient according to road width The figure which shows the correction coefficient according to elapsed time The figure which shows the warning action judgment map Diagram showing deceleration control operation determination map The figure explaining the effect by one embodiment The figure explaining the effect by one embodiment The figure explaining correction | amendment of the alarm action | operation determination threshold value according to a vehicle speed The figure explaining correction | amendment of the alarm action | operation determination threshold value according to elapsed time

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Driving assistance controller 1a-1d Control block 2 Navigation apparatus 3 Vehicle sensor 4 Audio | voice output apparatus 5 Brake control apparatus

Claims (9)

Road information detecting means for detecting information on the current position of the vehicle and the curve ahead of the vehicle;
Vehicle state detection means for detecting the current vehicle state;
Vehicle state estimation means for estimating a vehicle state at the time of passing the vehicle forward curve based on the current position of the vehicle, the curve information ahead of the vehicle and the current vehicle state;
Vehicle state storage means for storing the vehicle state detected by the vehicle state detection means when passing the curve;
An allowable vehicle state estimating means for estimating an allowable vehicle state at the time of the driver's curve passage based on a past vehicle state at the time of the curve passage stored in the vehicle state storage means;
A driving support apparatus comprising: a support operation determination unit that determines whether to perform driving support on a curve based on an estimated vehicle state when passing the vehicle forward curve and an allowable vehicle state when the driver passes the curve Because
The support operation determination means includes
When the difference between the estimated vehicle state and the allowable vehicle state is within a predetermined range, the value indicating the estimated vehicle state increases as the difference between the estimated vehicle state and the allowable vehicle state decreases. A driving support device that determines to perform support. The driving support device according to claim 1,
The driving support apparatus according to claim 1, wherein the vehicle state is a physical quantity related to a difficulty level of passing a curve. In the driving assistance device according to claim 2,
The driving support device characterized in that the vehicle state is at least one of a lateral acceleration, a yaw rate, a steering angle, and a steering angular velocity. In the driving assistance device according to any one of claims 1 to 3,
The driving support apparatus according to claim 1, wherein a maximum value among vehicle states at the time of past curve passage stored in the vehicle state storage means is set as an allowable vehicle state at the time of passing of the driver's curve. In the driving assistance device according to any one of claims 1 to 4,
A driving assistance device that corrects an estimated vehicle state at the time of passing the vehicle forward curve and an allowable vehicle state at the time of passing by the driver according to a driving environment and a driving state of the vehicle. The driving support device according to claim 5,
The driving environment includes road type, road width, prospect of the curve, road gradient, elapsed time from the time of passing the curve, distance between the curves, and the driving state includes the vehicle speed at the time of passing the curve. Is included. In the driving assistance device according to any one of claims 1 to 4,
The driving assistance is an alarm, and the assistance operation determination means warns when the vehicle forward curve passes based on the estimated vehicle state when the vehicle forward curve passes and the allowable vehicle state when the driver passes the curve. A driving support apparatus characterized by determining whether or not. In the driving assistance device according to any one of claims 1 to 4,
The driving assistance is deceleration control, and the assistance operation determination means decelerates until the vehicle forward curve passes based on the estimated vehicle state when the vehicle forward curve passes and the allowable vehicle state when the driver passes the curve. A driving support device that determines whether or not to perform control. In the driving assistance device according to any one of claims 1 to 8 ,
The allowable vehicle state estimation means includes
The driving assistance device, wherein the vehicle state at the time of the past curve passing is corrected based on an elapsed time from the curve passing date and time.

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