JP2009280100A - Vehicular deceleration controller and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly perform deceleration control even when one's own vehicle position is not accurately detected. <P>SOLUTION: The vehicular deceleration controller has: a braking/driving force control unit 8 performing the deceleration control of one's own vehicle based on a positional relationship between a curve in front of the vehicle and one's own vehicle position information provided by a navigation device 14; a control variations decision part 62 deciding whether the deceleration control by the braking/driving control unit 8 varies due to variations of the one's own vehicle position information provided by the navigation device 14; and a target deceleration change part 61 operating the deceleration control correspondingly to the curve in front of the vehicle with control contents different from control contents by the one's own vehicle position information provided by the navigation device 14 when the control variations decision part 62 decides that the deceleration control varies. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle deceleration control device and a method thereof for performing deceleration control of a vehicle with respect to a curve ahead of the vehicle.

Conventionally, there is a technique for detecting a host vehicle position and a curve ahead of the vehicle, and performing deceleration control based on the positional relationship between the detected host vehicle position and the curve ahead of the vehicle. In the apparatus disclosed in Patent Document 1, the target vehicle speed on the forward curve is calculated using information of the navigation system, and the target deceleration is calculated based on the calculated target vehicle speed and the own vehicle speed. In this device, the deceleration control is activated when the calculated target deceleration reaches a predetermined value.
JP-A-6-36187

By the way, the vehicle position may not be detected correctly. For example, this is the case when positioning itself cannot be performed by GPS (Global Positioning System) used in the navigation system, or when positioning data measured by GPS has an error. Therefore, in a device that detects the position of the host vehicle with the navigation system, such as the device disclosed in Patent Document 1, if the position of the host vehicle cannot be detected correctly with the navigation system, the target deceleration will fluctuate. . If the target deceleration varies in this way, the deceleration control also varies (for example, stepping occurs), and the deceleration control may give the driver a feeling of strangeness.
The subject of this invention is performing deceleration control appropriately, even when the own vehicle position cannot be detected correctly.

  In order to solve the above problems, the present invention detects a positional relationship between a vehicle and a curve ahead of the vehicle, and controls the vehicle to decelerate at a deceleration according to the detected positional relationship. When it is determined that the deceleration control varies due to the state, the deceleration control is operated with a control content different from that according to the detected state.

  According to the present invention, even when the vehicle position cannot be correctly detected and the detection state of the positional relationship with the curve ahead of the vehicle varies, the control content is different from that according to the detection state, thereby appropriately decelerating. Control can be activated.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(First embodiment)
First, the first embodiment will be described.
(Constitution)
1st Embodiment is a rear-wheel drive vehicle carrying the vehicle deceleration control apparatus which concerns on this invention. This rear-wheel drive vehicle is equipped with an automatic transmission and a conventional differential gear, and a braking device capable of independently controlling the braking force of the left and right wheels for both the front and rear wheels.

  FIG. 1 is a schematic configuration diagram showing the present embodiment. In the figure, reference numeral 1 is a brake pedal, 2 is a booster, 3 is a master cylinder, and 4 is a reservoir. Usually, the brake fluid pressure is increased by the master cylinder 3 in accordance with the depression amount of the brake pedal 1 by the driver, and the increased brake fluid pressure is supplied to the wheel cylinders 6FL to 6RR of the wheels 5FL to 5RR. Further, a brake fluid pressure control unit 7 is interposed between the master cylinder 3 and each wheel cylinder 6FL to 6RR.

  The braking fluid pressure control unit 7 uses a braking fluid pressure control unit used for antiskid control and traction control, for example. The braking fluid pressure control unit 7 individually controls the braking fluid pressures of the wheel cylinders 6FL to 6RR. And the brake fluid pressure control part 7 can control the brake fluid pressure independently. Further, when a braking fluid pressure command value is input from a braking / driving force control unit 8 described later, the braking fluid pressure control unit 7 can also control the braking fluid pressure according to the braking fluid pressure command value. . For example, the brake fluid pressure control unit 7 includes an actuator in the hydraulic pressure supply system. Examples of the actuator include a proportional solenoid valve capable of controlling each wheel cylinder hydraulic pressure to an arbitrary braking hydraulic pressure.

  Further, this vehicle is equipped with a drive torque control unit 12. The drive torque control unit 12 controls the drive torque to the rear wheels 5RL and 5RR which are drive wheels by controlling the operating state of the engine 9, the selected gear ratio of the automatic transmission 10, and the throttle opening of the throttle valve 11. To do. The drive torque control unit 12 controls the operating state of the engine 9 by controlling the fuel injection amount and ignition timing, and simultaneously controlling the throttle opening. The drive torque control unit 12 can also independently control the drive torque of the rear wheels 5RL and 5RR. Further, when a driving torque command value is input from the braking / driving force control unit 8, the driving torque control unit 12 can also control the driving wheel torque according to the driving torque command value. The drive torque control unit 12 outputs the value of the drive torque Tw used for control to the braking / driving force control unit 8.

  In addition, this vehicle is equipped with an external recognition sensor 13 for detecting a preceding vehicle. The external world recognition sensor 13 includes a millimeter wave radar 13a and a millimeter wave radar controller 13b. In the external recognition sensor 13, the millimeter wave radar controller 13b detects the inter-vehicle distance Lx to the preceding vehicle based on the detection result of the millimeter wave radar 13a. The outside recognition sensor 13 outputs the inter-vehicle distance Lx to the braking / driving force control unit 8.

The vehicle is equipped with a navigation device 14. The navigation device 14 searches for the road information ahead of the host vehicle based on the host vehicle position (X ₀ , Y ₀ ) measured by GPS and the map information (electronic map). Here, the road information ahead of the host vehicle is so-called node point information. The node point information consists of X _j , Y _j , L _j (j = 1 to n, n is an integer). X _j and Y _j are position information of the node point N _j . L _j is the distance from the vehicle position (X ₀ , Y ₀ ) to the position (X _j , Y _j ) of an arbitrary node point N _j . As for the relationship between the node points N _j, the larger the value of j, the farther the node point N _j is from the position (X ₀ , Y ₀ ) of the host vehicle. Further, the navigation device 14 can also obtain the own vehicle position (X ₀ , Y ₀ ) based on the vehicle state. For example, the host vehicle position can be obtained based on the vehicle speed and the yaw rate. The navigation device 14 outputs a map display, the current vehicle position, and the like to an output unit such as a monitor based on such node point information and the like. Similar information can also be obtained from an infrastructure facility installed in front of the curve by road-to-vehicle communication.

This vehicle is equipped with a warning monitor 15. The warning monitor 15 has a built-in speaker for generating sound and buzzer sound. The braking / driving force control unit 8 controls the operation of the warning monitor 15.
Further, the vehicle includes an acceleration sensor 16 that detects longitudinal acceleration Yg and lateral acceleration Xg, a yaw rate sensor 17 that detects yaw rate φ ′, an accelerator opening sensor 18 that detects an accelerator pedal depression amount, that is, an accelerator opening θt, A steering angle sensor 19 for detecting the steering angle δ of the steering wheel 21, a master cylinder pressure sensor 20 for detecting the output pressure of the master cylinder 3, that is, the master cylinder hydraulic pressure Pm, the rotational speeds of the wheels 5FL to 5RR, and the so-called wheel speed. Wheel speed sensors 22FL to 22RR for detecting Vwi (i = fl, fr, rl, rr) are mounted. These sensors and the like output detected signals and the like to the braking / driving force control unit 8.

  Further, this vehicle is equipped with an ACC switch 23 for ACC (adaptive cruise control). For example, the ACC switch 23 is attached to the steering wheel or the vehicle body. The ACC switch 23 includes a plurality of switches such as a main switch (MAIN SW), a reset switch (RES SW), and a set switch (SET SW). For example, when the set switch is pressed while the main switch is set, the ACC switch 23 outputs the host vehicle speed at that time as the set vehicle speed. The set vehicle speed is a vehicle speed for performing constant speed running.

  FIG. 2 shows a configuration example of the braking / driving force control unit 8. As shown in the figure, the braking / driving force control unit 8 includes a vehicle speed calculation unit 41, a target vehicle speed calculation unit 42, a navigation information processing unit 43, a target deceleration calculation unit 44, a target vehicle speed command value calculation unit 45, and an alarm control unit. 46, a vehicle speed setting unit 47, a vehicle speed command value calculation unit 48, a vehicle speed servo calculation unit 49, and a torque distribution control calculation unit 50. The torque distribution control calculation unit 50 includes a brake fluid pressure calculation unit 51 and an engine torque calculation unit 52. The braking / driving force control unit 8 can also include these components in the form of software, for example.

  FIG. 3 shows a processing procedure of arithmetic processing performed by the braking / driving force control unit 8. The processing procedure will be described together with the processing contents of the components shown in FIG. 2 with reference to FIG. The braking / driving force control unit 8 executes this calculation process by timer interruption every predetermined sampling time ΔT every 10 msec., For example. Information obtained by the arithmetic processing is updated and stored in the storage device as needed, and necessary information is read from the storage device as needed.

As shown in FIG. 3, when the process is started, first in step S1, the braking / driving force control unit 8 reads various data from the sensors, the controller, the control unit, and the like. Specifically, the own vehicle position (X ₀ , Y ₀ ) obtained by the navigation device 14 and the node point information (X _j , Y _j , L _j ) (j = 1 to n) on the road ahead are read. Further, each wheel speed Vwi, steering angle δ, accelerator opening θt, master cylinder hydraulic pressure Pm, and driving torque Tw from the driving torque control unit 12 detected by each sensor or the like are read. Further, the set vehicle speed is read from the ACC switch 23.

Subsequently, in step S2, the vehicle speed calculation unit 41 calculates the vehicle speed V. Specifically, the vehicle speed calculation unit 41 calculates the vehicle speed V by the following equation (1) based on the wheel speed Vwi read in step S1.
For front wheel drive V = (Vwr1 + Vwrr) / 2
For rear wheel drive V = (Vwfl + Vwfr) / 2
... (1)
Here, Vwfl and Vwfr are the wheel speeds of the left and right front wheels. Vwrl and Vwrr are the wheel speeds of the left and right rear wheels, respectively. In the equation (1), the vehicle speed V is calculated as an average value of the wheel speeds of the driven wheels. In this embodiment, since the vehicle is a rear-wheel drive vehicle, the vehicle speed V is calculated from the latter equation, that is, the wheel speed of the front wheels.

  The vehicle speed V calculated in this way is preferably used during normal travel. Further, when an ABS (Anti-lock Brake System) control or the like is operating, an estimated vehicle speed estimated in the ABS control can be used as the vehicle speed V. A value used for navigation information in the navigation device 14 can also be used as the vehicle speed V.

Subsequently, in step S3, the navigation information processing unit 43 calculates the turning radius of each node point ahead of the host vehicle. Specifically, the navigation information processing unit 43 determines each node point based on the coordinates (X _j , Y _j ) (j = 1 to n) of the node points that are the node point information of the forward road read in step S1. Calculate the turning radius of the node point. There are several methods for calculating the turning radius. In the present embodiment, a turn from the coordinates (X _j−1 , Y _j−1 ), (X _j , Y _j ), (X _{j + 1} , Yn _{j + 1} ) of three consecutive node points by the following equation (2) The radius R _j is calculated.
R _j = f ₁ (X _j−1 , Y _j−1 , X _j , Y _j , X _{j + 1} , Y _{j + 1} ) (2)
Here, the function f1 is a function for calculating the turning radius from the coordinates of the three node points. When the turning radius R _j is a negative value, it indicates a left turn, and when the turning radius R _j is a positive value, it indicates a right turn. For example, FIG. 4 shows an example of the turning radius R _j (● mark in the figure) obtained for each node point N _j (node point number).

Here, a method of calculating the turning radius from the coordinates ( _Xj-1 , _Yj-1 ), ( _Xj , _Yj ), ( _{Xj + 1} , _{Yj + 1} ) of three points is shown. However, the turning radius can also be calculated using an angle formed by a straight line connecting the preceding and following node points. Here, the turning radius is calculated based on the coordinates of each node point. However, the turning radius of each node point can be stored as node point information in the map data, and the value can be retrieved in this step S3. It is also possible to create complementary points that divide each node point at equal intervals so as to pass through each node point, and calculate the turning radius for each of the created complementary points.

Subsequently, in step S4, the target vehicle speed calculation unit 42 calculates the target vehicle speed at each node point. Specifically, the target vehicle speed calculation unit 42 calculates the target vehicle speed Vr _j by the following equation (3) using the turning radius R _j and the allowable lateral acceleration Yglimt of each node point calculated in step S3.
Vr _j = √ (Yglimt · | R _j |) (3)
Here, the allowable lateral acceleration Yglimt is a predetermined value, for example, 0.3 g. Further, the driver can set the allowable lateral acceleration Yglimt by a selection changeover switch. According to the equation (5), the target vehicle speed Vr increases as the allowable lateral acceleration Yglimt increases. It is also possible to create complementary points that divide each node point at equal intervals so as to pass through each node point, and calculate the target vehicle speed for each of the created complementary points.

Subsequently, in step S5, the target deceleration calculation unit 44 calculates a target deceleration. Specifically, the target deceleration calculation unit 44 is a node based on the vehicle speed V calculated in step S2, the target vehicle speed Vr _j calculated in step S4, and the current position (X ₀ , Y ₀ ) obtained by the navigation device 14. Using the distance L _j to the point N _j , the target deceleration Xgs _j is calculated by the following equation (4).
Xgs _j = (V ² −Vr _j ² ) / (2 · Ln _j )
= (V ² -Yglmit · | R _j |) / (2 · L _j ) (4)

Here, the target deceleration Xgs _j is given as a negative value (decreases) when decelerating, and is given (increased) as a positive value when accelerating. In calculating the target deceleration Xgs _j , the turning radius R _j , the distance L _j and the target vehicle speed Vr _j are values indicating the state of the curve ahead of the vehicle. According to the equation (4), the target deceleration Xgs _j decreases as the target vehicle speed Vr _j decreases (increases in absolute value). That is, as the target vehicle speed Vr _j decreases, a larger deceleration (absolute value) is required. Alternatively, the target deceleration Xgs _j decreases (the absolute value increases) as the host vehicle speed V increases. Alternatively, the target deceleration Xgs _j decreases as the allowable lateral acceleration Yglimt decreases. Alternatively, the target deceleration Xgs _j decreases as the absolute value | R _j | of the turning radius decreases. Alternatively, the target deceleration Xgs _j becomes smaller as the distance L _j becomes shorter. It is also possible to create complementary points that divide each node point at equal intervals so as to pass through each node point, and calculate the target deceleration for each of the created complementary points.

Subsequently, in step S6, the target deceleration calculation unit 44 detects the minimum target deceleration from the target deceleration Xgs _j at each node point. Specifically, the target deceleration calculation unit 44 detects the minimum value of the target deceleration (hereinafter referred to as the minimum target deceleration) Xgsmin by the following equation (5).
Xgsmin = min (Xgs _j ) (5)
Here, the function min from the target deceleration Xgs _j at each node point is a function for extracting the target deceleration Xgs _j minimum. The minimum target deceleration Xgsmin for detecting the node point (target node point) to be controlled can be obtained from the equation (5).

Subsequently, in step S7, the target vehicle speed command value calculation unit 45 calculates a target vehicle speed command value. Specifically, the target vehicle speed command value calculation unit 45 calculates the target vehicle speed command value Vrr by the following equation (6) using the minimum target deceleration Xgsmin detected in step S6.
Vrr = f2 (Xgsmin) · t (6)
Here, the function f2 is a function that limits a change in the minimum target deceleration Xgsmin. For example, the change amount limiter for limiting the change is set to 0.01 G / sec, for example. Further, the function f2 increases the target vehicle speed command value Vrr as Xgsmin increases. t indicates time (sampling time). According to the equation (6), the target vehicle speed command value Vrr changes by an amount corresponding to the change amount limiter and time t. That is, the target vehicle speed command value to which the deceleration change amount limiter is added is calculated by the equation (6).

  Subsequently, in step S8, the alarm control unit 46 makes an alarm activation start determination. The alarm control unit 46 performs the alarm operation start determination by, for example, a function (a function for determining the alarm operation start). Specifically, the alarm control unit 46 determines to start the alarm when the minimum target deceleration Xgsmin calculated in step S6 becomes less than the alarm activation determination threshold Xgsth1 (Xgsmin <Xgsth1). . When the alarm control unit 46 determines to activate the alarm, the alarm control unit 46 sets the alarm activation flag flg1 to 1 (flg1 = 1). For example, the threshold value Xgsth1 for alarm activation determination is an experimental value, an empirical value, or a theoretical value.

FIG. 5 shows the relationship between the minimum target deceleration Xgsmin and the alarm activation flag flg1. As shown in the figure, when the minimum target deceleration Xgsmin becomes less than the alarm activation determination threshold Xgsth1 (Xgsmin <Xgsth1), the alarm activation flag flg1 becomes 1 (flg1 = 1).
Subsequently, in step S9, the vehicle speed command value calculation unit 48 determines whether to start the deceleration control operation. The vehicle speed command value calculation unit 48 makes a deceleration control operation start determination using, for example, a combined function (a function for determining the start of deceleration control operation). Specifically, the vehicle speed command value calculation unit 48 starts operating the deceleration control when the minimum target deceleration Xgsmin calculated in step S6 becomes less than the deceleration control operation determination threshold value Xgsth2 (Xgsmin <Xgsth2). Make a decision. When the vehicle speed command value calculation unit 48 determines to operate the deceleration control, it sets the deceleration control operation flag flg2 to 1 (flg2 = 1). For example, the deceleration control operation determination threshold value Xgsth2 is an experimental value, an empirical value, or a theoretical value.

  Further, the threshold value Xgsth2 for determining the deceleration control operation is set to a value smaller than the threshold value Xgsth1 for alarm operation determination for determining the start of alarm operation (Xgsth2 <Xgsth1), so that the minimum target deceleration is achieved. When Xgsmin becomes smaller, it is first determined to activate an alarm and then to determine to operate deceleration control.

FIG. 6 shows the relationship between the minimum target deceleration Xgsmin and the deceleration control operation flag flg2. As shown in the figure, when the minimum target deceleration Xgsmin becomes less than the deceleration control operation flag flg2 (Xgsmin <Xgsth2), the deceleration control operation flag flg2 becomes 1 (flg2 = 1). That is, as the target vehicle speed Vr _j becomes smaller or the distance L _j becomes shorter, the minimum target deceleration Xgsmin becomes smaller (see the equations (4) and (5)), so the deceleration control operation flag flg2 becomes 1. It becomes easy.

Subsequently, in step S10, the vehicle speed servo calculation unit 49 calculates a target acceleration / deceleration. The target acceleration / deceleration is a control amount for achieving the target vehicle speed command value Vrr calculated in step S7. Specifically, when the deceleration control operation flag flg2 becomes 1, that is, when it is determined that the deceleration control is to be activated, the vehicle speed servo calculation unit 49 sets the target acceleration / deceleration in order to achieve the target vehicle speed command value Vrr. calculate. For example, the target acceleration / deceleration is calculated as a difference value between the target vehicle speed command value Vrr and the host vehicle speed V.
Subsequently, in step S11, the torque distribution control calculation unit 50 calculates torque distribution. Specifically, the torque distribution control calculation unit 50 calculates the torque distribution of the brake torque and the engine torque so that the target acceleration / deceleration calculated in step S10 is realized by the brake torque and the engine torque. Specifically, the calculation is performed as follows.

In order to realize the brake torque, the brake fluid pressure calculation unit 51 calculates a target brake fluid pressure for each wheel. Specifically, the brake fluid pressure calculation unit 51 calculates the target control fluid pressure using the target acceleration / deceleration calculated in step S10 when it is determined to start the deceleration control (flg2 = 1). For example, the brake hydraulic pressure calculation unit 51 calculates the control target hydraulic pressure Ps by the following equation (7) using the target acceleration / deceleration Xg ^* .
Ps = Kb · Xg ^* (7)
Here, Kb is a constant determined from brake specifications and the like. According to the equation (7), the control target hydraulic pressure Ps increases as the target acceleration / deceleration Xg ^* increases. The control target hydraulic pressure Pc is realized by the respective target brake hydraulic pressures Psfr and Psrr for the front and rear wheels (for example, Psfr = Psrr = Ps / 2).

Further, in order to realize the engine torque, the engine torque calculation unit 52 calculates the driving force of the driving wheels. Specifically, when the engine torque calculation unit 52 determines to start the deceleration control (flg2 = 1), the target drive is performed using the control target hydraulic pressure Ps and the accelerator opening Acc according to the following equation (8). Torque Trqds is calculated.
Trqds = f3 (Acc) −f4 (Ps) (8)
Here, the function f3 (Acc) is a function for calculating the target drive torque Trqds according to the accelerator opening Acc. f4 (Ps) is a function for calculating a braking torque that is predicted to be generated by the control target hydraulic pressure Pc.

When deceleration control is not performed (flg2 = 0), the target drive torque Trqds is calculated by the following equation (9).
Trqds = f3 (Acc) (9)
From the above, when the automatic deceleration control is operating, the target drive torque Trqds is calculated according to the accelerator opening Acc and the control amount f4 (Ps) of the automatic deceleration control (equation (8)). As a result, even if the driver performs an accelerator operation during the operation of the automatic deceleration control, the engine output is reduced to prevent acceleration. When the automatic deceleration control is not operating, the target drive torque Trqds is calculated according to the accelerator opening Acc (Equation (9)).

  Subsequently, in step S12, warning and deceleration control are performed. For the alarm, the alarm control unit 46 activates the alarm monitor 15 at the timing when the alarm is activated (when flg1 becomes 1). For example, an alarm sound is output from the alarm monitor 15 to display an alarm. However, the present invention is not limited to this, and an alarm can also be implemented by HUD (Head-up Display), voice utterance from the navigation system, navigation screen display, and meter display. Regarding the deceleration control, the brake hydraulic pressure calculation unit 51 and the engine torque calculation unit 52 are at the timing when the determination to activate the deceleration control is made (when flg2 becomes 1), and the target braking hydraulic pressure Psi calculated in step S11. Based on (Psfr, Psrr) and the target drive torque Trqds, a control signal is output to the brake fluid pressure control unit 7 and the drive torque control unit 12. Thereby, braking force and driving force are controlled. As a result, the vehicle decelerates according to the braking force and the driving force.

  Next, a specific calculation processing procedure performed by the braking / driving force control unit 8 will be described. FIG. 7 shows the specific processing procedure. As shown in the figure, in this process, a process of step S21 is provided between the process of step S6 and the process of step S7 with respect to the process shown in FIG. And the braking / driving force control unit 8 is provided with the target deceleration change part 61 and the control fluctuation | variation determination part 62, as shown in FIG. 8, in order to implement | achieve the process of step S21. Here, in the process shown in FIG. 7, the process denoted by the same reference numeral (step number) as the reference numeral (step number) given in the process of FIG. It is the same as the process. Further, in FIG. 8, the processing of components having the same reference numerals as those of the components in FIG. 2 is the same as the processing of components in FIG. 2 unless otherwise specified. is there.

In step S21, the target deceleration changing unit 61 changes the minimum target deceleration Xgsmin obtained in the preceding calculation process. Specifically, first, the control variation determination unit 62 determines whether or not the deceleration control varies (varies) due to the detection state of the host vehicle position. More specifically, the control variation determination unit 62 determines whether or not the deceleration control varies based on the minimum target deceleration Xgsmin indicating the deceleration according to the distance between the host vehicle position and the curve ahead of the vehicle. The control variation determination unit 62 determines (estimates) that the deceleration control varies when the minimum target deceleration Xgsmin (absolute value) is smaller than a predetermined value. Here, the predetermined value is an experimental value, an empirical value, or a theoretical value. For example, when the deceleration due to the deceleration control is small, that is, for example, when the deceleration control is operated at a position far from the curve ahead of the vehicle, the deceleration control is more easily affected by variations in detection of the host vehicle position. As a result, at a position far from the curve ahead of the vehicle, the deceleration control varies more. Therefore, from such a viewpoint, a predetermined value for determining whether or not the deceleration control varies is determined. For example, the predetermined value can be set as the deceleration control operation determination threshold value Xgsth2. It can also be determined (estimated) that the deceleration control varies when the distance (L _j ) between the host vehicle and the vehicle forward curve is greater than a predetermined value. The predetermined value here is also determined from the viewpoint of determining whether or not the deceleration control varies. The predetermined value is an experimental value, an empirical value, or a theoretical value. Furthermore, it is possible to determine (estimate) the fluctuation of the deceleration control based on the minimum target deceleration Xgsmin and the distance (L _j ) between the host vehicle and the vehicle forward curve. For example, when the minimum target deceleration Xgsmin is smaller than a predetermined value (first predetermined value) and the distance (L _j ) between the host vehicle and the vehicle forward curve is larger than a predetermined value (second predetermined value), It is determined (estimated) that the deceleration control fluctuates.

  At the same time, it is also possible to determine whether or not the deceleration control varies with reference to other information. For example, when the vehicle position information is actually varied and the minimum target deceleration Xgsmin (absolute value) is smaller than a predetermined value, it is determined that the deceleration control varies. For example, when there is an error between the own vehicle obtained from the own vehicle speed and the own vehicle position obtained based on the positioning information, it is determined that the own vehicle position varies.

Then, the target deceleration changing unit 61 calculates a changed minimum target deceleration (hereinafter referred to as a changed minimum target deceleration) Xgsh when the control variation determining unit 62 determines that the deceleration control varies. Specifically, the target deceleration changing unit 61 changes the minimum target deceleration Xgsmin according to the following equation (10) when the minimum target deceleration Xgsmin becomes equal to or smaller than a predetermined value (when the predetermined target value is reached). Then, the minimum change target deceleration Xgsh is calculated.
Xgsh = f5 (Xgsmin) (10)

  Here, the function f5 is the minimum target deceleration Xgsmin (= predetermined value) when the minimum target deceleration Xgsmin is equal to or less than a predetermined value (when it reaches the predetermined value), and the changed minimum target deceleration Xgsh. , A function for holding the value for a predetermined time. Here, when the predetermined value is the deceleration control operation determination threshold value Xgsth2, the changed minimum target deceleration Xgsh is held as the deceleration control operation determination threshold value Xgsth2 for a predetermined time. The predetermined time is a fixed value (for example, 1 second). Further, the select low value between the fixed value (for example, 1 second) and the update time of the vehicle position (node point) can be set as the predetermined time. That is, the predetermined time can be made shorter than the vehicle position update time.

Further, after holding for a predetermined time (after the predetermined time elapses), the change minimum target deceleration Xgsh is calculated by subtracting the change minimum target deceleration Xgsh by the function f5. For example, the minimum target deceleration Xgsmin is subtracted by the following equation (11).
Xgsh (= f5 (Xgsmin)) = Xgsh−Δxgsh (11)
Here, Δxgsh is a constant. According to the equation (11), the changed minimum target deceleration rate Xgsh gradually decreases according to the number of repetitions of the arithmetic processing in FIG. For this reason, for example, Δxgsh is set so that the degree of change in the change minimum target deceleration Xgsh is a predetermined degree. For example, Δxgsh is set so as to decrease more than the general reduction rate of the minimum target deceleration rate Xgsmin when the deceleration control is intervened.

  In the subsequent processing, processing is performed using the changed minimum target deceleration Xgsh instead of the minimum target deceleration Xgsmin. That is, in step S7, the target vehicle speed command value calculation unit 45 calculates a target vehicle speed command value Vrr (= f2 (Xgsh) · t) based on the changed minimum target deceleration Xgsh. In step S9, the start of deceleration control operation is determined based on the changed minimum target deceleration Xgsh. Specifically, the vehicle speed command value calculation unit 48 determines to start the deceleration control when the changed minimum target deceleration Xgsh becomes less than the deceleration control operation determination threshold value Xgsth2 (Xgsh <Xgsth2). Also in step S8, it is possible to make a warning activation start determination using the changed minimum target deceleration Xgsh. In this case, when the changed minimum target deceleration rate Xgsh becomes less than the threshold value Xgsth1 for determining the alarm operation (Xgsh <Xgsth1), the alarm control unit 46 determines to start the alarm operation.

(Operation and action)
Operation and action are as follows.
First, according to the process shown in FIG. 3, the vehicle deceleration control device reads various data during the traveling of the vehicle (step S1) and calculates the vehicle speed V (step S2). Further, the vehicle deceleration control device calculates the turning radius R _j of each node point in front of the host vehicle, and based on the calculated turning radius R _j of each node point, the vehicle speed Vr _j at each node point is calculated. Calculate (step S3, step S4). Further, the vehicle deceleration control device calculates a target deceleration Xgs _j at each node point based on the target vehicle speed Vr _j at each node point (step S5). Then, the vehicle deceleration control apparatus detects the target deceleration Xgsmin minimum value from the target deceleration Xgs _j at each node point, on the basis of the minimum target deceleration Xgsmin that the detected, calculates a target vehicle speed command value Vrr (Steps S6 and S7). Further, the vehicle deceleration control device calculates a target deceleration Xg ^* on the basis of the target vehicle speed command value Vrr, based on the target deceleration Xg ^* with the calculated, torque distribution of the braking torque and the engine torque (Ps, Trqds ) Is calculated (steps S10 and S11). On the other hand, the vehicle deceleration control device makes an alarm activation start determination and a deceleration control activation start determination based on the minimum target deceleration Xgsmin (steps S8 and S9). Then, the vehicle deceleration control device performs the alarm and deceleration control based on the determination result of the alarm operation start determination and the deceleration control operation start determination (states of flg1 and flg2) (step S12).

  On the other hand, the vehicle deceleration control device calculates the changed minimum target deceleration Xgsh from the minimum target deceleration Xgsmin by the processing shown in FIG. 7 (step S21). Specifically, the vehicle deceleration control apparatus calculates the changed minimum target deceleration Xgsh when the minimum target deceleration Xgsmin becomes equal to or less than a predetermined value (for example, deceleration control operation determination threshold value Xgsth2). That is, the minimum target deceleration Xgsmin is held for a predetermined time, and then (after the predetermined time has elapsed), the changed minimum target deceleration Xgsh is calculated as a value that gradually decreases the minimum target deceleration Xgsmin (the above equation (10)). (11)).

  FIG. 9 shows the relationship among the minimum target deceleration Xgsmin, the deceleration control operation flag flg2, and the control target hydraulic pressure. As shown in the figure, when the minimum target deceleration Xgsmin decreases and reaches the deceleration control operation determination threshold value Xgsth2, the changed minimum target deceleration Xgsh is calculated. The changed minimum target deceleration Xgsh gradually decreases after being held for a predetermined time. Then, the target vehicle speed command value Vrr calculated based on the changed minimum target deceleration Xgsh (see the above equation (6)) gradually decreases. At this time, when the changed minimum target deceleration Xgsh starts to decrease (Xgsh <Xgth2), the deceleration control operation flag flg2 becomes 1, and the deceleration control is started (see step S12). That is, the deceleration control is started after the intervention timing (operation start timing) is delayed. The deceleration control is performed based on the target vehicle speed command value Vrr that gradually decreases as described above. In this deceleration control, the target control hydraulic pressure is generated according to the target vehicle speed command value Vrr.

Here, in this embodiment, deceleration control is performed based on the own vehicle position information provided by the navigation device 14, specifically, the own vehicle position measured by GPS. That is, the minimum target deceleration Xgsmin is calculated based on the host vehicle position (X ₀ , Y ₀ ) provided by the navigation device 14, and the target vehicle speed command value Vrr is calculated based on the calculated minimum target deceleration Xgsmin. (Formulas (4) to (6)).

  Here, consider a case where the vehicle position information provided by the navigation device 14 varies. For example, there are cases where the position of the vehicle cannot be measured by GPS, or there is an error although it is measured. Further, there may be a case where there is a measurement error in the vehicle speed sensor (wheel speed sensors 22FL to 22RR) or the yaw rate sensor 17 that detects the position of the host vehicle. Further, the navigation device 14 may provide the position of the host vehicle displayed on the map created based on the rough map database as it is. In these cases, since the own vehicle position is shifted back and forth from the actual one, the own vehicle position information varies as it is updated. As a result, for example, although the host vehicle is traveling at a constant speed, a change in distance from the curve ahead of the vehicle is detected as being discontinuous. If the vehicle position information varies as described above, the minimum target deceleration Xgsmin also varies, and the target vehicle speed command value Vrr also varies. For example, in a scene where the vehicle approaches the curve to be controlled (the node point where the minimum target deceleration Xgsmin is obtained), if the target vehicle speed command value Vrr varies due to variations in the vehicle position information (for example, If it becomes discontinuous), the deceleration that changes in accordance with the curve to be controlled varies, and stepping occurs in the deceleration control.

  On the other hand, by changing the minimum target deceleration Xgsmin to the changed minimum target deceleration Xgsh and performing deceleration control based on the changed minimum target deceleration Xgsh, the variation in the vehicle position information provided by the navigation device 14 is varied. It is possible to appropriately perform deceleration control without being affected by the above. In other words, by performing deceleration control based on the changed minimum target deceleration Xgsh obtained irrespective of the host vehicle position information provided by the navigation device 14, it is possible to appropriately perform the deceleration control regardless of variations in the host vehicle position. Can do.

Moreover, since the control content of the deceleration control is changed by determining the variation of the deceleration control, it is possible to prevent the control content of the deceleration control from being changed carelessly. That is, it is possible to prevent the control content of the deceleration control from being inadvertently changed when the own vehicle position information varies but the deceleration control does not change.
The first embodiment can also be realized by the following configuration.

  That is, in the first embodiment, it is determined whether or not the deceleration control varies based on the minimum target deceleration Xgsmin. On the other hand, it can also be determined whether or not the deceleration control varies directly from the detection state of the vehicle position by GPS or the like. Moreover, it can also be determined whether deceleration control fluctuates based on the update history of the map database. For example, it is determined that there is a high possibility that the deceleration control fluctuates as the update history of the map database becomes older. This is because when the map database is old, a map matching error is likely to occur, and as a result, an error is likely to occur in the own vehicle position.

  In the first embodiment, the minimum target deceleration Xgsmin is changed to the changed minimum target deceleration Xgsh. On the other hand, the threshold value Xgsth2 for determining the deceleration control operation can be changed. In this case, when the minimum target deceleration Xgsmin becomes equal to or less than the deceleration control operation determination threshold value Xgsth2 (when reached), the deceleration control operation determination threshold value Xgsth2 is changed to a small value.

  In the first embodiment, the predetermined time for holding the changed minimum target deceleration Xgsh (minimum target deceleration Xgsmin) is set as a fixed value. On the other hand, the predetermined time can be a variable. Specifically, the predetermined time can be determined based on the traveling environment of the host vehicle. Here, the traveling environment of the host vehicle includes the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the travel path. 10 to 13 below show examples of the predetermined time (holding time).

  FIG. 10 shows the relationship between the arrival time and the holding time. The arrival time is the time until the host vehicle reaches the forward curve (the curve indicated by the node point that obtained the minimum target deceleration Xgsmin). As shown in the figure, in the region where the arrival time is short, the holding time is lengthened as the arrival time becomes longer. In a region where the arrival time is long, the holding time is kept constant regardless of the arrival time. That is, as a rule, the longer the arrival time, the longer the holding time.

  FIG. 11 shows the relationship between the forward curve turning radius and the holding time. The forward curve turning radius is the turning radius of the node point at which the minimum target deceleration Xgsmin is obtained. As shown in the figure, in a region where the forward curve turning radius is small, the holding time is set to a constant small value (for example, 1 second). When the forward curve turning radius becomes larger than a certain value, the holding time is lengthened as the forward curve turning radius becomes larger. When the forward curve turning radius is further increased, the holding time is set to a constant large value regardless of the forward curve turning radius. That is, as a general rule, the holding time is lengthened as the forward curve turning radius increases.

  FIG. 12 shows the relationship between the vehicle speed difference (deviation) between the target vehicle speed and the actual vehicle speed and the holding time. The target vehicle speed is the calculated value in step S7, and the actual vehicle speed is the calculated value in step S2. As shown in the figure, in a region where the vehicle speed difference is large, the holding time is set to a constant large value. When the vehicle speed difference becomes greater than a certain value, the holding time is shortened as the vehicle speed difference increases. When the vehicle speed difference further increases, the holding time is set to a constant small value (for example, 1 second) regardless of the vehicle speed difference. That is, as a general rule, the holding time is shortened as the vehicle speed difference increases.

  FIG. 13 shows the relationship between the road gradient of the traveling road and the holding time. As shown in the figure, if the traveling direction is a downward slope, the holding time is set to a constant small value (for example, 1 second) regardless of the degree of the slope. On the other hand, if the traveling direction is an upward gradient, the holding time is increased as the gradient degree increases. When the gradient degree becomes a certain magnitude, the holding time is set to a constant large value regardless of the gradient degree. That is, as a general rule, if the slope is ascending, the holding time is lengthened as the slope degree increases.

For example, the holding time can be determined by a combination of the arrival time, the forward curve turning radius, the vehicle speed difference, and the road gradient. For example, the holding time can be determined by weighting the arrival time, the forward curve turning radius, the vehicle speed difference, and the road gradient.
Further, in the first embodiment, the case has been described in which the alarm operation start determination and the deceleration control operation start determination are performed based on the minimum target deceleration Xgsmin or the changed minimum target deceleration Xgsh. On the other hand, it is also possible to make an alarm operation start determination or a deceleration control operation start determination based on other determination criteria. That is, for example, it is also possible to make a warning operation start determination or a deceleration control operation start determination using the target vehicle speed command value Vrr.

  FIG. 14 shows a process when the alarm activation start determination is performed using the target vehicle speed command value Vrr. As shown in the figure, the warning control unit 46 makes a warning activation start determination using the set vehicle speed Vset, the host vehicle speed V, and the target vehicle speed command value Vrr. Regarding the set vehicle speed Vset, the vehicle speed setting unit 47 outputs the set vehicle speed Vset to the alarm control unit 46 in accordance with the operation signal of the ACC switch 23. In this alarm activation start determination, for example, when the set vehicle speed Vset is equal to the host vehicle speed V (Vset = V), the target vehicle speed command value Vrr is less than the set vehicle speed Vset (own vehicle speed V). (Vrr <Vset), the alarm activation flag flg1 is set to 1 (flg1 = 1). Thereby, when the alarm activation flag flg1 becomes 1, the alarm is activated.

  FIG. 15 shows a process when the deceleration control operation start determination is performed using the target vehicle speed command value Vrr. As shown in the figure, the vehicle speed command value calculation unit 48 makes a warning activation start determination using the set vehicle speed Vset, the host vehicle speed V, and the target vehicle speed command value Vrr. Regarding the set vehicle speed Vset, the vehicle speed setting unit 47 outputs the set vehicle speed Vset to the vehicle speed command value calculation unit 48 in accordance with the operation signal of the ACC switch 23. In this deceleration control operation start determination, for example, when the set vehicle speed Vset and the host vehicle speed V are equal (Vset = V), the vehicle speed command value calculation unit 48 sets the target vehicle speed command value Vrr to the set vehicle speed Vset (host vehicle speed V). When it is less than (Vrr <Vset), the deceleration control operation flag flg2 is set to 1 (flg2 = 1). Thus, when the deceleration control operation flag flg2 becomes 1, the deceleration control is activated (braking fluid pressure rises).

  In this embodiment, the minimum target deceleration Xgsmin is changed to the changed minimum target deceleration Xgsh. Thereby, the control command value for the deceleration control is replaced from the minimum target deceleration Xgsmin to the changed minimum target deceleration Xgsh. On the other hand, the changed minimum target deceleration Xgsh can be calculated while maintaining the calculation of the minimum target deceleration Xgsmin. That is, the minimum target deceleration Xgsmin and the changed minimum target deceleration Xgsh are calculated in parallel. Thereby, deceleration control can be performed by selecting either the minimum target deceleration Xgsmin or the changed minimum target deceleration Xgsh. For example, the deceleration control is operated based on the select low value of the minimum target deceleration Xgsmin and the changed minimum target deceleration Xgsh. Thereby, it is possible to operate the deceleration control with a necessary deceleration while preventing the deceleration control from varying.

  In the first embodiment, the navigation device 14 realizes a positional relationship detection means for detecting the positional relationship between the vehicle and the curve ahead of the vehicle. The vehicle speed calculation unit 41, the target vehicle speed calculation unit 42, the navigation information processing unit 43, the target deceleration calculation unit 44, the target vehicle speed command value calculation unit 45, the alarm control unit 46, the vehicle speed command value calculation unit 48, and the vehicle speed servo calculation unit. 49, a torque distribution control calculation unit 50, a brake fluid pressure calculation unit 51, and an engine torque calculation unit 52 are vehicle speed control means (deceleration control for the vehicle at a deceleration corresponding to the positional relationship detected by the positional relationship detection means). 1st vehicle speed control means) is realized. Further, the control fluctuation determination unit 62 realizes a determination unit that determines whether or not the deceleration control by the vehicle speed control unit varies due to the detection state of the positional relationship detection unit. In addition, when the determination unit determines that the deceleration control varies, the target deceleration changing unit 61 decelerates according to the curve ahead of the vehicle with a control content different from that based on the detection result of the positional relationship detection unit. A control content changing means for operating the control by the vehicle speed control means is realized.

Further, in the first embodiment, the target deceleration changing unit 61 is a second vehicle speed control that performs deceleration control of the vehicle in accordance with a curve ahead of the vehicle on a basis different from the detection result of the positional relationship detection means. And a control content changing means for operating the deceleration control by switching from the first vehicle speed control means to the second vehicle speed control means when the determination means determines that the deceleration control varies.
Further, in the first embodiment, the positional relationship between the vehicle and the curve ahead of the vehicle is detected, and the vehicle deceleration control performed at a deceleration corresponding to the detected vehicle forward curve is performed to detect the positional relationship. When there is a possibility of variation due to the state, a vehicle deceleration control method for operating the deceleration control corresponding to the curve ahead of the vehicle is realized with the control content corresponding to the possibility.

(effect)
The effects of the first embodiment are as follows.
(1) When it is determined that the deceleration control varies due to the detection state of the own vehicle position, the deceleration control is operated with a control content different from that according to the detection state. Specifically, the minimum target deceleration Xgsmin is changed to the changed minimum target deceleration Xgsh, and the deceleration control is operated based on the changed minimum target deceleration Xgsh. Thereby, even when the own vehicle position cannot be detected correctly and the own vehicle position information varies, the deceleration control can be appropriately activated by setting the control content different from that based on the own vehicle position information. .

(2) After the minimum target deceleration Xgsmin is changed to the changed minimum target deceleration Xgsh and held for a predetermined time, the deceleration control is started based on the changed minimum target deceleration Xgsh. Accordingly, it is possible to prevent the deceleration control from being operated by the changed minimum target deceleration Xgsh far from the minimum target deceleration Xgsmin, and to decelerate the host vehicle with an appropriate deceleration.

(3) By changing the minimum target deceleration Xgsmin to the changed minimum target deceleration Xgsh, the intervention timing of the deceleration control is delayed, while the change degree of the changed minimum target deceleration Xgs is set to a predetermined degree. Specifically, the changed minimum target deceleration rate Xgsh is decreased at a decreasing rate larger than that based on the own vehicle position information. Thus, even when the intervention timing of the deceleration control is delayed, the host vehicle can be decelerated with an appropriate deceleration that secures a necessary amount with respect to the vehicle forward curve.

(4) A predetermined time (holding time) is determined based on the traveling environment of the host vehicle. As a result, the changed minimum target deceleration rate Xgsh changes according to the traveling environment of the host vehicle. Thereby, the deceleration control based on the changed minimum target deceleration Xgsh can be adapted to the traveling environment of the host vehicle.
(5) The predetermined time is determined based on at least one of the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the travel path. Accordingly, the deceleration control based on the changed minimum target deceleration Xgsh is adapted to a specific driving environment such as the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the road. Can be activated.

(6) The holding time for holding the changed minimum target deceleration Xgsh is a select low value between a fixed value (for example, 1 second) and the update time of the vehicle position (node point). That is, the holding time is set to be shorter than the own vehicle position update time. Accordingly, it is possible to prevent the holding time from becoming longer than necessary, and to operate the deceleration control at an optimal timing.
(7) When the minimum target deceleration Xgmin (absolute value) is smaller than a predetermined value, it is determined that the deceleration control varies. As a result, variation in deceleration control can be detected easily and accurately.
(8) When the distance between the host vehicle and the curve ahead of the vehicle is greater than a predetermined value, it is determined that the deceleration control varies. As a result, variation in deceleration control can be detected easily and accurately.

(Second Embodiment)
A second embodiment will be described.
(Constitution)
Similar to the first embodiment, the second embodiment is a rear-wheel drive vehicle equipped with the vehicle deceleration control device according to the present invention.
The configuration of the vehicle according to the second embodiment is the same as that shown in FIG. 1 as in the first embodiment. FIG. 16 shows a processing procedure in the second embodiment. As shown in the figure, in the second embodiment, the basic processing is the same as the processing shown in FIG. 3 as in the case of the first embodiment. However, in the second embodiment, a new process of step S31 is provided between the process of step S6 and the process of step S7. The braking / driving force control unit 8 includes a target deceleration changing unit 61 in the same manner as in FIG. 8 in order to realize the processing of step S31. Here, in the process shown in FIG. 16, the process denoted by the same reference numeral (step number) as the reference numeral (step number) assigned to the arithmetic process of FIG. This is the same as the operation processing of No. 3.

In step S31, the target deceleration changing unit 61 corrects the minimum target deceleration Xgsmin obtained in step S6 of the preceding process. Specifically, as in the first embodiment, first, the control variation determination unit 62 determines whether or not the deceleration control varies due to the detection state of the host vehicle position. Then, the target deceleration changing unit 61 calculates the changed minimum target deceleration (changed minimum target deceleration) Xgsh when the control variation determining unit 62 determines that the deceleration control varies. More specifically, the target deceleration changing unit 61 changes the minimum target deceleration Xgsmin according to the following equation (12) when the minimum target deceleration Xgsmin is less than or equal to a predetermined value (when it reaches the predetermined value): The minimum target deceleration after change (changed minimum target deceleration) Xgsh is calculated.
Xgsh = f6 (Xgsmin) (12)
Here, the predetermined value is an experimental value, an empirical value, or a theoretical value. For example, the predetermined value can be set as the deceleration control operation determination threshold value Xgsth2. The function f6 is a function for setting the minimum target deceleration Xgsmin to a changed minimum target deceleration Xgsh that is a predetermined value (reset value).

Then, after the change, the changed minimum target deceleration rate Xgsh is subtracted. For example, similarly to the first embodiment, the changed minimum target deceleration Xgsh is subtracted by the following equation (13).
Xgsh = Xgsh−Δxgsh (13)
Here, Δxgsh is a constant. According to the equation (13), the changed minimum target deceleration rate Xgsh gradually decreases according to the number of repetitions of the arithmetic processing in FIG. For this reason, for example, Δxgsh is set so that the degree of change in the change minimum target deceleration Xgsh is a predetermined degree. For example, Δxgsh is set so as to decrease more than the general reduction rate of the minimum target deceleration rate Xgsmin when the deceleration control is intervened.

  In the subsequent processing, processing is performed using the changed minimum target deceleration Xgsh instead of the minimum target deceleration Xgsmin. That is, in step S7, the target vehicle speed command value calculation unit 45 calculates a target vehicle speed command value Vrr (= f2 (Xgsh) · t) based on the changed minimum target deceleration Xgsh. In step S9, the start of deceleration control operation is determined based on the changed minimum target deceleration Xgsh. Specifically, the vehicle speed command value calculation unit 48 determines to start the deceleration control when the changed minimum target deceleration Xgsh becomes less than the deceleration control operation determination threshold value Xgsth2 (Xgsh <Xgsth2). Also in step S8, it is possible to make a warning activation start determination using the changed minimum target deceleration Xgsh. In this case, when the changed minimum target deceleration rate Xgsh becomes less than the threshold value Xgsth1 for determining the alarm operation (Xgsh <Xgsth1), the alarm control unit 46 determines to start the alarm operation.

(Operation and action)
Operation and action are as follows. In particular, in the second embodiment, the vehicle deceleration control device sets the minimum target deceleration Xgsmin when the changed minimum target deceleration Xgsh is equal to or lower than the deceleration control operation determination threshold value Xgsth2 by the processing shown in FIG. The minimum change target deceleration Xgsh is set (step S31).
FIG. 17A shows the relationship between the deceleration control operation flag flg2 and the changed minimum target deceleration Xgsh in the second embodiment. As shown in FIG. 5A, when the minimum target deceleration Xgsmin decreases and reaches the deceleration control operation determination threshold value Xgsth2, the changed minimum target deceleration Xgsh is calculated. Then, immediately after the change, the change minimum target deceleration Xgsh gradually decreases. Then, the target vehicle speed command value Vrr calculated based on the changed minimum target deceleration Xgsh (see the above equation (6)) gradually decreases. At this time, when the changed minimum target deceleration Xgsh starts to decrease (Xgsh <Xgth2), the deceleration control operation flag flg2 becomes 1, and the deceleration control is started (see step S12). The deceleration control is performed based on the target vehicle speed command value Vrr that gradually decreases as described above. In this deceleration control, the target control hydraulic pressure is generated according to the target vehicle speed command value Vrr.

  Here, also in the second embodiment, the same operation as in the first embodiment can be obtained by operating the deceleration control based on the changed minimum target deceleration Xgsh. That is, by changing from the minimum target deceleration Xgsmin to the changed minimum target deceleration Xgsh and performing deceleration control based on the changed minimum target deceleration Xgsh, the influence of variations in the vehicle position information provided by the navigation device 14 is affected. It is possible to appropriately perform deceleration control without receiving it.

The second embodiment can also be realized by the following configuration.
That is, in the second embodiment, when the minimum target deceleration Xgsmin becomes equal to or less than a predetermined value (for example, the deceleration control operation determination threshold value Xgsth2), the minimum target deceleration Xgsmin is immediately changed to the minimum target deceleration Xgsh. (Refer to the above formulas (12) and (13)). On the other hand, when the minimum target deceleration Xgsmin becomes equal to or lower than a predetermined value (for example, the threshold value Xgsth2 for determining deceleration control operation), the minimum target deceleration Xgsmin may be gradually increased to the changed minimum target deceleration Xgsh. it can. By doing so, the timing at which the deceleration control operation flag flg2 becomes 1 can be delayed as shown in FIG.

In the second embodiment, the reset value (changed minimum target deceleration rate Xgsh) is a fixed value. On the other hand, the reset value can be a variable. Specifically, the reset value can be determined based on the traveling environment of the host vehicle. Here, the traveling environment of the host vehicle includes the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the travel path. 18 to 21 below show examples of α (reset value).
FIG. 18 shows the relationship between the arrival time and the reset value. As shown in the figure, in the region where the arrival time is short, the reset value is increased as the arrival time becomes longer. In the region where the arrival time is long, the reset value is kept constant regardless of the arrival time. That is, as a general rule, the reset value is increased as the arrival time increases.

  FIG. 19 shows the relationship between the forward curve turning radius and the reset value. As shown in the figure, in a region where the forward curve turning radius is small, the reset value is set to a constant small value (for example, 1 second). When the forward curve turning radius is larger than a certain value, the reset value is increased as the forward curve turning radius is increased. When the forward curve turning radius is further increased, the reset value is set to a constant large value regardless of the forward curve turning radius. That is, as a general rule, the reset value is increased as the forward curve turning radius increases.

  FIG. 20 shows the relationship between the vehicle speed difference (deviation) between the target vehicle speed and the actual vehicle speed and the reset value. The target vehicle speed is the calculated value in step S7, and the actual vehicle speed is the calculated value in step S2. As shown in the figure, in a region where the vehicle speed difference is large, the reset value is set to a constant large value. When the vehicle speed difference becomes larger than a certain value, the reset value is decreased as the vehicle speed difference becomes larger. When the vehicle speed difference further increases, the reset value is set to a constant small value (for example, 1 second) regardless of the vehicle speed difference. That is, as a general rule, the reset value is decreased as the vehicle speed difference increases.

FIG. 21 shows the relationship between the road gradient in the traveling direction and the reset value. As shown in the figure, if the traveling direction is a downward gradient, the reset value is set to a constant small value (for example, 1 second) regardless of the degree of gradient. On the other hand, if the traveling direction is an upward gradient, the reset value is increased as the gradient degree increases. When the gradient degree reaches a certain magnitude, the reset value is set to a constant large value regardless of the gradient degree. That is, as a general rule, if the slope is an upward slope, the reset value is increased as the slope degree increases.
For example, the reset value can be determined by the combination of the arrival time, the forward curve turning radius, the vehicle speed difference, and the road gradient. In this case, for example, the reset value can be determined by weighting the arrival time, the forward curve turning radius, the vehicle speed difference, and the road gradient.

(effect)
The effects of the second embodiment are as follows.
(1) When it is determined that the deceleration control varies due to the detection state of the own vehicle position, the deceleration control is operated with a control content different from that according to the detection state. Specifically, the minimum target deceleration Xgsmin is changed to the changed minimum target deceleration Xgsh, and the deceleration control is operated based on the changed minimum target deceleration Xgsh. Thereby, even when the own vehicle position cannot be detected correctly and the own vehicle position information varies, the deceleration control can be appropriately activated by setting the control content different from that based on the own vehicle position information. .

(2) The minimum target deceleration rate Xgsmin is set to a predetermined minimum target deceleration rate Xgsh. Thus, even when the deceleration control is operated using the changed minimum target deceleration Xgsh that is not related to the host vehicle position, the host vehicle can be decelerated with a desired deceleration.
(3) By changing the minimum target deceleration Xgsmin to the changed minimum target deceleration Xgsh, the intervention timing of the deceleration control is delayed, while the change degree of the changed minimum target deceleration Xgs is set to a predetermined degree. Specifically, the changed minimum target deceleration rate Xgsh is decreased at a decreasing rate larger than that based on the own vehicle position information. Thus, even when the intervention timing of the deceleration control is delayed, the host vehicle can be decelerated with an appropriate deceleration that secures a necessary amount with respect to the vehicle forward curve.

(4) The predetermined minimum change target deceleration Xgsh is determined according to the traveling environment of the host vehicle. Thereby, the deceleration control based on the changed minimum target deceleration Xgsh can be adapted to the traveling environment of the host vehicle.
(5) The changed minimum target deceleration Xgsh is determined based on at least one of the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the travel path. Accordingly, the deceleration control based on the changed minimum target deceleration Xgsh is adapted to a specific driving environment such as the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the road. Can be activated.

(Third embodiment)
A third embodiment will be described.
(Constitution)
As in the first embodiment, the third embodiment is a rear-wheel drive vehicle equipped with the vehicle deceleration control device according to the present invention.
The configuration of the vehicle of the third embodiment is the configuration shown in FIG. 1 as in the case of the first embodiment. FIG. 22 shows a processing procedure in the third embodiment. As shown in the figure, in the third embodiment, the basic processing is the same as the processing shown in FIG. 3 as in the case of the first embodiment. However, in the third embodiment, the process of step S41 is provided between the process of step S9 and the process of step S10. And the braking / driving force control unit 8 is provided with the deceleration control start judgment change part 71, as shown in FIG. 23, in order to implement | achieve the process of step S41. Here, in the process shown in FIG. 22, the process denoted by the same reference numeral (step number) as the reference numeral (step number) assigned to the calculation process of FIG. This is the same as the processing in step 3. Also, in FIG. 23, the processing of components having the same reference numerals as those of the components in FIG. 2 is the same as the processing of components in FIG. 2 unless otherwise specified. is there.

  In step S41, the deceleration control start determination changing unit 71 changes the deceleration control operation flag flg2 set in the process of step S9 in the preceding stage. Specifically, as in the first embodiment, first, the control variation determination unit 62 determines whether or not the deceleration control varies due to the detection state of the host vehicle position. Then, the deceleration control start determination changing unit 71 sets the deceleration control operation flag flg2 set to 1 in step S9 to zero when the control variation determination unit 62 determines that the deceleration control varies. More specifically, the deceleration control start determination changing unit 71 sets the deceleration control operation flag flg2 to zero when the minimum target deceleration Xgsmin becomes less than the deceleration control operation determination threshold value Xgsth2 (Xgsmin <Xgsth2) ( flg2 = 0). Then, this set state (flg2 = 0) is held for a predetermined time, and then the deceleration control operation flag flg2 is set to 1.

(Operation and action)
Operation and action are as follows. Particularly in the third embodiment, the vehicle deceleration control device sets the deceleration control operation flag flg2 to zero when the minimum target deceleration Xgsmin becomes less than the deceleration control operation determination threshold value Xgsth2 by the processing shown in FIG. Set to. Then, the vehicle deceleration control device retains the set state (flg2 = 0) for a predetermined time, retains the predetermined state for a predetermined time, and then sets the deceleration control operation flag flg2 to 1 (step S41).

  FIG. 24 shows the relationship between the deceleration control operation flag flg2 and the minimum target deceleration Xgsmin in the third embodiment. As shown in the figure, when the minimum target deceleration Xgsmin becomes less than the deceleration control operation determination threshold value Xgsth2, the deceleration control operation flag flg2 is set to zero. Then, after holding for a predetermined time, the deceleration control operation flag flg2 is set to 1. That is, the timing for setting the deceleration control operation flag flg2 to 1 is delayed. Note that, while the deceleration control operation flag flg2 is held at zero, the minimum target deceleration Xgsmin normally decreases, so the minimum target deceleration Xgsmin is maintained below the deceleration control operation determination threshold value Xgsth2. ing. Therefore, even if the deceleration control operation flag flg2 is not particularly set to 1 after holding for a predetermined time, the deceleration control is normally performed by processing based on the relationship between the minimum target deceleration Xgsmin and the deceleration control operation determination threshold value Xgsth2. The operation flag flg2 is set to 1. Thus, when the deceleration control operation flag flg2 is set to 1 (when it returns to 1), the target vehicle speed command value Vrr is calculated based on the minimum target deceleration Xgsmin at that time ((6) above) See formula). By delaying the timing at which the deceleration control operation flag flg2 is set to 1 for a predetermined time, the host vehicle speed V is not reduced (because the host vehicle speed V is maintained at a high value), the minimum target deceleration Xgsmin at this time is normally It becomes smaller than the value of (is larger in absolute value). That is, a larger deceleration is required for the forward curve as compared to the case of normal intervention.

  As described above, since the minimum target deceleration Xgsmin is reduced, the third embodiment can provide the same operation as that of the first embodiment. That is, by performing the deceleration control based on the minimum target deceleration Xgsmin smaller than the normal one, it is possible to appropriately perform the deceleration control without being affected by variations in the vehicle position information provided by the navigation device 14. it can. For example, for the purpose of preventing the deceleration generated by the deceleration control from becoming excessive, it is conceivable to set the upper limit value of the deceleration and operate the deceleration control. Such a measure is useful in carrying out deceleration control while maintaining a stable traveling state, such as preventing the wheels from being locked. When such measures are taken, if the deceleration control intervention timing is delayed and deceleration control is started with a small minimum target deceleration Xgsmin (large minimum target deceleration Xgsmin in absolute value), the minimum target at that time If the deceleration Xgsmin exceeds the upper limit value, the deceleration control is operated with the deceleration maintained at the upper limit value. That is, the deceleration control is operated at the deceleration of the upper limit value until the minimum target deceleration Xgsmin becomes larger than the upper limit value. As described above, when the deceleration control is operated with the deceleration of the upper limit value, the deceleration control is performed regardless of the minimum target deceleration Xgsmin even if the minimum target deceleration Xgsmin is affected by the variation of the own vehicle position information. Therefore, the deceleration control is activated without being affected by this. Therefore, it is possible to appropriately perform the deceleration control without being affected by variations in the own vehicle position information.

The third embodiment can also be realized by the following configuration.
That is, in the third embodiment, the timing for setting the deceleration control operation flag flg2 to 1 is delayed. On the other hand, the threshold value Xgsth2 for determining the deceleration control operation can be changed. That is, when the control variation determination unit 62 determines that the deceleration control varies, the threshold value Xgsth2 for determining the deceleration control operation is changed to a small value. By doing in this way, it is possible to obtain an operation equivalent to delaying the timing for setting the deceleration control operation flag flg2 to 1.
In addition, the predetermined time during which the deceleration control operation flag flg2 is held at zero can be set to a fixed value, and as described with reference to FIGS. 10 to 13, the predetermined time (holding time) is set between the host vehicle and the front of the vehicle. It can be determined based on the traveling environment of the host vehicle such as the positional relationship with the other curve, the turning radius of the curve ahead of the vehicle, the road gradient of the traveling road, and the like.

(effect)
The effects of the third embodiment are as follows.
(1) When it is determined that the deceleration control varies due to the detection state of the own vehicle position, the deceleration control is operated with a control content different from that according to the detection state. Specifically, the deceleration control is operated based on the minimum target deceleration Xgsmin by delaying the intervention timing of the deceleration control. Thereby, even when the own vehicle position cannot be detected correctly and the own vehicle position information varies, the deceleration control can be appropriately activated by setting the control content different from that based on the own vehicle position information. .

(2) By delaying the intervention timing of the deceleration control, the deceleration control is operated with a control content different from that based on the own vehicle position information. Thereby, the deceleration control can be appropriately operated with a control content different from that based on the vehicle position information by a simple process of delaying the intervention timing of the deceleration control.
(3) The deceleration control operation determination threshold value Xgsth2 is changed to delay the intervention timing of the deceleration control. Thus, the intervention timing of the deceleration control can be delayed by a simple process such as changing the deceleration control operation determination threshold value Xgsth2.

(4) A predetermined time (holding time) is determined based on the traveling environment of the host vehicle. As a result, the minimum target deceleration Xgsmin after the change (after the start of deceleration control) changes according to the traveling environment of the host vehicle. Thereby, the deceleration control based on the minimum target deceleration Xgsmin can be adapted to the traveling environment of the host vehicle.
(5) The predetermined time is determined based on at least one of the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the travel path. Accordingly, the deceleration control based on the minimum target deceleration Xgsmin is performed in accordance with a specific traveling environment such as the positional relationship between the host vehicle and the curve ahead of the vehicle, the turning radius of the curve ahead of the vehicle, and the road gradient of the road. Can be operated.

It is a figure which shows the structure of the vehicle of embodiment of this invention. It is a block diagram which shows the structural example of a braking / driving force control unit. It is a flowchart which shows the process sequence of the arithmetic processing performed with a braking / driving force control unit. It is a figure which shows turning radius _Rj (● mark in a figure) of each node point _Nj (node point number). It is a characteristic view which shows the relationship between the minimum target deceleration Xgsmin and the warning operation flag flg1. FIG. 5 is a characteristic diagram showing a relationship between a minimum target deceleration Xgsmin and a deceleration control operation flag flg2. It is a flowchart which shows the process sequence of the specific arithmetic processing performed with a braking / driving force control unit. It is a block diagram which shows the structural example of the braking / driving force control unit for implement | achieving the process of FIG. FIG. 6 is a characteristic diagram showing a relationship among a minimum target deceleration Xgsmin, a deceleration control operation flag flg2, and a control target hydraulic pressure. It is a characteristic view which shows the relationship between arrival time and holding time. It is a characteristic view which shows the relationship between the front curve turning radius and holding time. It is a characteristic view showing the relationship between the vehicle speed difference (deviation) between the target vehicle speed and the actual vehicle speed and the holding time. It is a characteristic view which shows the relationship between the road gradient of a running direction, and holding time. It is the figure used for description of the process at the time of making a warning action start determination using the target vehicle speed command value Vrr. It is the figure used for description of the process at the time of performing the deceleration control action start judgment using the target vehicle speed command value Vrr. It is a flowchart which shows the process sequence of the braking / driving force control unit in 2nd Embodiment. FIG. 12 is a characteristic diagram showing a relationship between a deceleration control operation flag flg2 and a changed minimum target deceleration Xgsh in the second embodiment. It is a characteristic view which shows the relationship between arrival time and a reset value. It is a characteristic view which shows the relationship between a forward curve turning radius and a reset value. It is a characteristic view showing the relationship between the vehicle speed difference (deviation) between the target vehicle speed and the actual vehicle speed and the reset value. It is a characteristic view which shows the relationship between the road gradient of a running direction, and a reset value. It is a flowchart which shows the process sequence of the braking / driving force control unit in 3rd Embodiment. It is a block diagram which shows the structural example of the braking / driving force control unit for implement | achieving the process of FIG. It is a characteristic view which shows the relationship between the deceleration control action flag flg2 and the minimum target deceleration Xgsmin in 3rd Embodiment.

Explanation of symbols

  8 Braking / driving force control unit, 14 navigation device, 41 vehicle speed calculation unit, 42 target vehicle speed calculation unit, 43 navigation information processing unit, 44 target deceleration calculation unit, 45 target vehicle speed command value calculation unit, 46 alarm control unit, 47 vehicle speed Setting unit, 48 Vehicle speed command value calculating unit, 49 Vehicle speed servo calculating unit, 50 Torque distribution control calculating unit, 51 Brake fluid pressure calculating unit, 52 Engine torque calculating unit, 61 Target deceleration changing unit, 62 Control variation determining unit, 71 Deceleration control start judgment change section

Claims (12)

A positional relationship detecting means for detecting a positional relationship between the vehicle and a curve ahead of the vehicle;
Vehicle speed control means for decelerating the vehicle at a deceleration according to the positional relation detected by the positional relation detection means;
Determination means for determining whether or not the deceleration control by the vehicle speed control means varies due to the detection state of the positional relationship detection means;
Control that causes the vehicle speed control means to actuate the deceleration control corresponding to the curve ahead of the vehicle with a control content different from that based on the detection result of the positional relationship detection means when the determination means determines that the deceleration control varies. Content change means,
A vehicle deceleration control device comprising:   2. The control content changing unit, after holding a deceleration according to the positional relationship detected by the positional relationship detecting unit for a predetermined time, operates the deceleration control based on the deceleration. The vehicle deceleration control device described in 1.   3. The vehicle deceleration control device according to claim 1, wherein the control content changing means operates the deceleration control at a predetermined deceleration. 4.   The control content changing means starts the deceleration control at an operation start timing that is later than an operation start timing corresponding to the positional relationship detected by the positional relationship detection means. The vehicle deceleration control device according to claim 1. The vehicle speed control unit compares the deceleration according to the positional relationship detected by the positional relationship detection unit with a predetermined threshold value, and starts the deceleration control.
The control content changing unit starts the deceleration control at an operation start timing that is later than an operation start timing corresponding to the positional relationship detected by the positional relationship detecting unit by changing the predetermined threshold value. The vehicle deceleration control device according to any one of claims 1 to 4, wherein the vehicle deceleration control device is provided.   When the deceleration control is operated at an operation start timing different from the operation start timing according to the positional relationship detected by the positional relationship detection unit, the control content changing unit changes the deceleration change according to the positional relationship. The vehicle deceleration control device according to any one of claims 1 to 5, wherein the deceleration is changed at a rate different from the rate.   The vehicular deceleration control device according to any one of claims 1 to 6, wherein the control content changing unit varies the control content according to a traveling environment of the vehicle.   8. The vehicle according to claim 7, wherein the travel environment of the vehicle is at least one of a positional relationship between the vehicle and a curve ahead of the vehicle, a turning radius of the curve ahead of the vehicle, and a road gradient of the travel path. Deceleration control device.   The determination means determines that the deceleration control varies when a deceleration according to the positional relationship is smaller than a predetermined threshold value determined corresponding to the deceleration. The vehicle deceleration control device according to any one of 1 to 8.   The determination means determines that the deceleration control varies when a distance between the vehicle and a curve ahead of the vehicle is larger than a predetermined threshold value determined corresponding to the distance. The vehicle deceleration control apparatus according to any one of 1 to 9. A positional relationship detecting means for detecting a positional relationship between the vehicle and a curve ahead of the vehicle;
First vehicle speed control means for decelerating the vehicle at a deceleration corresponding to the positional relationship detected by the positional relationship detection means;
Second vehicle speed control means for decelerating the vehicle in response to a curve ahead of the vehicle on a basis different from the detection result of the positional relationship detection means;
Determination means for determining whether or not the deceleration control by the vehicle speed control means varies due to the detection state of the positional relationship detection means;
Control content changing means for switching the first vehicle speed control means to the second vehicle speed control means to activate the deceleration control when the determination means determines that the deceleration control varies.
A vehicle deceleration control device comprising:   The positional relationship between the vehicle and the curve ahead of the vehicle is detected, and the vehicle deceleration control performed at a deceleration corresponding to the detected vehicle forward curve may vary due to the detected state of the positional relationship. A deceleration control method for a vehicle, wherein the deceleration control is operated in accordance with a curve in front of the vehicle with a control content corresponding to the possibility.

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