JP4973086B2 - Vehicle driving support apparatus and method - Google Patents

Description

  The present invention relates to a vehicle driving support device that supports driving during curve driving.

When there is a continuous curve in front of the vehicle, the vehicle is decelerated to the appropriate vehicle speed for passing through the first curve, and the vehicle is passed through the second and subsequent curves while maintaining the appropriate vehicle speed for the first curve. A vehicle driving support device is known (for example, see Patent Document 1).
In this vehicle driving support device, when the second curve is steeper than the first curve, the appropriate vehicle speed for passing the second curve is reset after passing the first curve.

Prior art documents related to the invention of this application include the following.
JP 2002-362183 A

However, in the above-described conventional vehicle driving support device, when the first curve is steep and the second and subsequent curves are loose, the second and subsequent curves are displayed at a low vehicle speed for passing the first steep curve. Since the vehicle passes, it passes through the second and subsequent curves at a vehicle speed lower than the appropriate vehicle speed of those curves, which gives the driver a sense of incongruity. Further, the vehicle passes between the curves while maintaining a low vehicle speed for passing through the first curve, which makes the driver feel uncomfortable.
In addition, if the first curve is loose and the second curve is very steep, the appropriate vehicle speed for the second steep curve will be reset after passing the first curve, so you will be forced to decelerate suddenly. Or the vehicle may pass the second steep curve at a vehicle speed higher than the appropriate vehicle speed without slowing down, giving the driver a sense of incongruity.

The vehicle driving support apparatus according to the present invention includes a distance to two or more curves ahead of the vehicle position, curve information detecting means for detecting a turning radius of each curve, and a turning radius of each curve. And based on the preset lateral acceleration at the time of passing the curve, the target passing speed calculating means for calculating the target passing speed of each curve, the target passing speed of each curve, the own vehicle speed, and the own vehicle position Corresponding to the first calculation means for calculating the reference acceleration / deceleration from the vehicle position to each curve based on the distance to each curve and the arrival time from the vehicle position to the curve. The storage means for storing the acceleration / deceleration correction value in advance and the acceleration / deceleration correction value read from the storage means are added to the reference acceleration / deceleration calculated by the first calculating means. Based on the second calculation means for calculating the target acceleration / deceleration of the curve, the target vehicle speed pattern calculation means for selecting the minimum value of the target acceleration / deceleration of each curve, and the minimum value selected by the target vehicle speed pattern calculation means And an acceleration / deceleration control means for controlling the acceleration / deceleration of the host vehicle .
The driving support method according to the present invention includes a distance to two or more curves ahead of the vehicle position, a curve information detecting step for detecting a turning radius of each curve, a turning radius of each curve, Based on the set lateral acceleration at the time of passing the curve, a target passing speed calculating step for calculating the target passing speed of each curve, the target passing speed of each curve, the own vehicle speed, and the vehicle position from the own vehicle position. A first calculation step for calculating a reference acceleration / deceleration from the vehicle position to each curve based on the distance to the vehicle, and an adjustment corresponding to the arrival time from the vehicle position to the curve. By using a storage unit that stores a speed correction value in advance, the acceleration / deceleration correction value read from the storage unit is added to the reference acceleration / deceleration calculated by the first calculation unit, thereby Based on the second calculation step for calculating the target acceleration / deceleration of the probe, the target vehicle speed pattern calculation step for selecting the minimum value of the target acceleration / deceleration of each curve, and the minimum value selected by the target vehicle speed pattern calculation step And an acceleration / deceleration control process for controlling the acceleration / deceleration of the host vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the optimal vehicle speed which a driver does not feel uncomfortable between curves can be implement | achieved.

  FIG. 1 is a diagram showing a configuration of an embodiment. A controller for driving support control (hereinafter simply referred to as a controller) 1 is composed of peripheral components such as a microcomputer and a memory, and calculates a target value for acceleration / deceleration control based on information about the curve ahead of the vehicle and the state of the vehicle. Control engine torque and brake torque.

  The navigation device 2 detects the position of the host vehicle using a GPS receiver or the like, searches the road map database for information relating to a curve existing ahead of the host vehicle, and sends the information to the controller 1. In this embodiment, a curve existing within a predetermined range (for example, a range up to 500 m) from the vehicle position is detected, and the turning radius for each curve and the distance to the curve are output to the controller 1 as curve information. . Note that the turning radius R may be calculated every predetermined distance (for example, 10 m) from the vehicle position and output to the controller 1 as curve information.

  The vehicle sensor 3 is a variety of sensors that detect the vehicle state, and includes a vehicle speed sensor that detects the vehicle speed, an engine rotation sensor that detects the engine rotation speed, a gear ratio sensor that detects the gear ratio of the automatic transmission, and the like. The engine controller 4 adjusts the throttle opening and the like according to the target engine torque from the controller 1 to control the torque of the engine (not shown). The brake controller 5 controls the brake torque by adjusting the hydraulic pressure of the brake device in accordance with the target brake hydraulic pressure from the controller 1.

  FIG. 2 is a control block diagram for explaining the control of the controller 1 for driving support control. The operation of the embodiment will be described with reference to this figure. In the following, it is assumed that n pieces of curve information are provided from the navigation device 2 in order from the closest to the host vehicle ahead of the host vehicle, and the numbers i = 1, 2, ..Identify with n. Note that at least two pieces of curve information (n ≧ 2) are necessary.

<< (1) Calculation of target passing speed for each curve >>
The turning radius of each curve is R_i (i = 1, 2,..., N). The target passing speed v_i of each curve is calculated by the following equation so that the lateral acceleration ay generated when traveling on each curve is constant.
v_i = sqrt (R_i · ay) (1)

  In this embodiment, an example is shown in which the target passing speed v_i of each curve is set so that the lateral acceleration at the time of traveling on each curve is constant. For example, a large lateral acceleration is set in the low speed range, and the high speed range is set. Then, a small lateral acceleration may be set. Further, the lateral acceleration may be increased as the road ahead of the curve is better, the road width of the curve is wider, the cant of the curve is larger, and the lateral acceleration coefficient μ is smaller as the curve friction coefficient μ of the curve is smaller.

<< (2) Calculation of standard acceleration / deceleration up to each curve >>
The distance from the vehicle position provided by the navigation device 2 to each curve is d_i (i = 1, 2,..., N), and the current vehicle speed detected by the vehicle sensor 3 is v. Reference pressure deceleration acc_i (i = 1,2, ··, n) is the acceleration when the vehicle travels at a deceleration constant from the vehicle position to each curve is calculated by the following equation (2).
acc_i = (v_i ² −v ² ) /2.0/d_i (2)
In the equation (2), v_i is a target passing speed of each curve obtained by the equation (1).

<< (3) Calculation of time to reach each curve >>
The time to reach each curve is a required time when the vehicle travels from the vehicle position to each curve at a constant acceleration / deceleration, and is calculated by the following equation (3).
t_i = 2 · d_i / (v_i + v) (3)
In equation (3), v_i is the target passing speed of each curve obtained by equation (1), d_i is the distance from the vehicle position to each curve, and v is the current vehicle speed.

<< (4) Calculation of target acceleration / deceleration for each curve >>
First, (3) based on the time t_i reaching each curve calculated expression, obtaining the (2) the correction value of the reference pressure decrease rate acc_i determined by equation acc_h_i (i = 1,2, ··, n) . FIG. 3 is a map of the correction value acc_h_i for the arrival time t_i to each curve, and this map is stored in advance in a memory (not shown) of the controller 1. In the map shown in FIG. 3, basically, a larger correction value acc_h_i is set as the arrival time t_i is longer and the vehicle speed v is lower.

Next, the correction value acc_h_i is added to the reference acceleration reduction acc_i of each curve, and a target acceleration / deceleration acc_t_i (i = 1, 2,..., N) until the curve is reached is obtained.
acc_t_i = acc_i + acc_h_i (4)

  Thereby, for example, when the distance from the vehicle position to the next curve is short, the arrival time t_i to the next curve is short, so the correction value acc_h_i becomes 0, and the reference acceleration / deceleration acc_i becomes the target acceleration / deceleration acc_t_i. The change in acceleration / deceleration is small until the next curve.

A calculation example of a specific target acceleration / deceleration will be shown. As shown in FIG. 4, when the vehicle passes the curve 1 at the target passing speed v_1, the distance (d_2-d_1) to the curve 2 is short, and the current vehicle speed v (= If the target passing speed v_2 target passing speed v_1) and curve 2 are equal, it is calculated as a reference pressure decrease rate acc_2 = 0 to the curve 2 by (2). Next, since the arrival time t_2 to the curve 2 calculated by the equation (3) is short, the correction value acc_h_2 = 0 from the map shown in FIG. Accordingly, the target acceleration / deceleration acc_t_2 = 0 up to the curve 2 is calculated by the equation (4), and the vehicle passes through the vehicle from the curve 1 to the curve 2 at a constant vehicle speed without acceleration / deceleration.

  On the other hand, when the distance from the vehicle position to the next curve is long, the arrival time t_i to the next curve is long, so the correction value acc_h_i becomes large, and the correction value acc_h_i is added to the reference acceleration / deceleration acc_i, resulting in a large target The acceleration / deceleration acc_t_i is calculated, and after accelerating, the vehicle decelerates and enters the next curve.

  A specific calculation example in this case is shown. As shown in FIG. 5, when the vehicle passes the curve 1 at the target passing speed v_1, the distance to the curve 2 (d_2-d_1) is long, and the current vehicle speed while passing through the curve 1 (= target passing speed). When v_1) and the target passing speed v_2 of curve 2 are equal, the reference acceleration acc_2 = 0 up to curve 2 is calculated by equation (2). Next, since the arrival time t_2 to the curve 2 calculated by the equation (3) is long, a large correction value acc_h_2 is retrieved from the map shown in FIG. Therefore, the target acceleration / deceleration acc_t_2 up to the large curve 2 is calculated by the equation (4), and after accelerating after passing through the curve 1, when approaching the curve 2, decelerate to the target passing speed v_2 of the curve 2 and enter the curve 2. become.

Further, since the vehicle speed v is smaller higher correction value Acc_h_i, if such is traveling on an expressway is not performed a large reference acceleration speed correction becomes smaller the correction value Acc_h_i, a smooth travel. On the other hand, when the vehicle speed v is low correction value acc_h_i performed is large becomes to large reference acceleration speed correction, the running was crisp.

<< (5) Search for minimum target acceleration / deceleration acc_t >>
The minimum value is retrieved from the target acceleration / deceleration acc_t_i (i = 1, 2,..., N) of each curve and set as the target acceleration / deceleration acc_t.
acc_t = min (acc_t_1, acc_t_2, ..., acc_t_n) (5)

  As shown in FIG. 6, when there is a gentle curve 1 in front and a very steep curve 2 next, the target acceleration / deceleration acc_t_2 for the next steep curve 2 is the target acceleration / deceleration for the loose curve 1 in front. Since it becomes smaller than acc_t_1, it behaves like starting deceleration on the next steep curve 2 before entering the gentle curve 1 in front.

<< (6) Calculation of torque distribution >>
The target engine torque trq_eng and the target brake hydraulic pressure Pbrk are calculated using the target acceleration / deceleration acc_lim after the target acceleration / deceleration acc_t obtained by the equation (5) is limited with a predetermined upper and lower limit value. First, the target engine torque trq_eng is calculated by the following equation (6).
trq_w = (acc_lim−acc_r) · r_tire / m,
trq_eng = trq_w / (n_at, n_def, n_trq) (6)
In equation (6), acc_r is the running resistance (<0), m is the vehicle weight, r_tire is the tire radius, trq_w is the target wheel torque, n_at is the gear ratio of the automatic transmission, n_def is the gear ratio of the differential gear, and n_trq is Torque ratio of torque converter.

Next, the target brake fluid pressure trq_w_est is calculated by the following equation (7). First, the driving force generated by the engine brake is calculated.
trq_w_est = n_at, n_def, n_trq, trq_eng_est (7)
In equation (7), trq_eng_est is the engine torque when the throttle is fully closed. Then, the target brake fluid pressure Pbrk is calculated by the following equation (8).
Pbrk = -Kbrk (trq_w-trq_w_est) (8)
In the equation (8), Kbrk is a ratio between the driving force and the brake fluid pressure.

  In the embodiment described above, the engine and brake torque distribution is calculated based on the target acceleration / deceleration, and the engine and brake are controlled. However, the target vehicle speed pattern is calculated by integrating the target acceleration / deceleration, A similar effect can be obtained even when the actual vehicle speed is fed back to the vehicle speed.

  As described above, according to one embodiment, the distance to at least two or more curves closest to the host vehicle ahead of the host vehicle and the turning radius of those curves are detected, and the turning radius of each curve is determined in advance. Calculate the target passing speed of each curve based on the set lateral acceleration at the time of passing the curve, and calculate the target vehicle speed pattern for each curve so that the target passing speed is obtained at the entrance of each curve. Since the minimum value of the patterns is selected to control the acceleration / deceleration of the host vehicle, it is possible to realize an optimal vehicle speed that does not cause the driver to feel uncomfortable between the curves.

Further, according to one embodiment, based on the distance to each curve, the target passing speed of each curve, and the current vehicle speed, the reference acceleration / deceleration up to each curve and the time to reach each curve are calculated, corrects the reference acceleration based on the arrival time to the curve, since the minimum value of the reference acceleration corrected and to control the acceleration and deceleration of the vehicle as a target acceleration, operating between curve and curve It is possible to achieve an optimal vehicle speed that does not give the user a sense of incongruity.

  Furthermore, according to one embodiment, since the reference acceleration / deceleration is increased as the arrival time to the curve is longer or the vehicle speed is lower, the first curve is abrupt and the second and subsequent curves are increased. If the curve is loose, it will decelerate to the first steep curve and accelerate to the second curve after passing the first curve, so between the first curve and the second curve, and The driver will not feel uncomfortable by passing the second curve at a vehicle speed lower than the appropriate vehicle speed.

The figure which shows the structure of one embodiment Control block diagram for explaining the control of the controller for driving support control The figure which shows the example map of the acceleration correction value with respect to the arrival time to the curve Diagram showing calculation example of target acceleration / deceleration Diagram showing another example of target acceleration / deceleration Diagram showing another example of target acceleration / deceleration

Explanation of symbols

1 Controller for driving support control 2 Navigation device 3 Vehicle sensor 4 Engine controller 5 Brake controller

Claims (6)

And the distance to two or more of each curve in the front of the vehicle position, the curve information detecting means for detecting a turning radius of each of these curves,
On the basis of the lateral acceleration at the time of passing curves preset the turning radius of the curve, the target passing speed calculation means for calculating a target rate of passage of the respective curves,
First calculation means for calculating a reference acceleration / deceleration from the vehicle position to each curve based on the target passing speed of each curve, the vehicle speed, and the distance from the vehicle position to each curve. When,
Storage means for preliminarily storing acceleration / deceleration correction values corresponding to the arrival time from the vehicle position until the vehicle reaches each curve;
Second calculation means for calculating a target acceleration / deceleration of each curve by adding the acceleration / deceleration correction value read from the storage means to the reference acceleration / deceleration calculated by the first calculation means;
Target vehicle speed pattern calculating means for selecting the minimum value of the target acceleration / deceleration of each curve ;
A vehicle driving support apparatus comprising: acceleration / deceleration control means for controlling acceleration / deceleration of the host vehicle based on the minimum value selected by the target vehicle speed pattern calculating means . The vehicle driving support device according to claim 1,
The vehicular driving support apparatus , wherein the storage means stores in advance a plurality of types of acceleration / deceleration correction values corresponding to a combination of the arrival time and the host vehicle speed . In the vehicle driving assistance device according to claim 1 or 2 ,
The reference acceleration / deceleration calculated by the first calculation means is an acceleration / deceleration calculated when the vehicle travels at a constant acceleration / deceleration from the vehicle position to each curve. apparatus. In the vehicle driving assistance device according to any one of claims 1 to 3 ,
The acceleration / deceleration correction value stored in the storage means has a larger value as the host vehicle speed is lower. In the vehicle driving support device according to any one of claims 1 to 4,
The arrival time from the vehicle position to the curve is calculated based on the target passing speed of the curve, the vehicle speed, and the distance from the vehicle position to the curve. A vehicle driving support device characterized by the above. A curve information detecting step for detecting a distance to each of two or more curves ahead of the vehicle position and a turning radius of each of the curves;
A target passing speed calculating step of calculating a target passing speed of each curve based on a turning radius of each curve and a preset lateral acceleration when passing the curve;
A first calculation step of calculating a reference acceleration / deceleration from the vehicle position to each curve based on the target passing speed of each curve, the vehicle speed, and the distance from the vehicle position to each curve. When,
Using the storage means for storing in advance acceleration / deceleration correction values corresponding to the arrival time from the host vehicle position until reaching each curve, the acceleration / deceleration correction values read from the storage means are used as the first acceleration / deceleration correction values. A second calculation step of calculating a target acceleration / deceleration of each curve by adding to the reference acceleration / deceleration calculated by the calculation means;
A target vehicle speed pattern calculating step of selecting a minimum value of the target acceleration / deceleration of each curve;
A driving support method comprising: an acceleration / deceleration control step for controlling acceleration / deceleration of the host vehicle based on the minimum value selected in the target vehicle speed pattern calculation step.

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