JPH08132931A - Travel control device for vehicle - Google Patents

Abstract

PURPOSE: To provide a travel control device performing vehicle speed control and alarm control with timing coinciding with the operating timing of a driver during follow-up travel. CONSTITUTION: An inter-vehicle distance sensor and a vehicle speed sensor 12 are provided to detect the speed of an own vehicle, relative speed and inter- vehicle distance. A control device ECU14 computes brake starting inter-vehicle distance under the fixed condition of deceleration on the basis of a specified driver model equation and compares it with the present inter-vehicle distance so as to control a brake 20 and a throttle 22 to control the vehicle speed and also to control a display 24 and a speaker 26 to output an alarm. The driver model equation is determined according to the limit inter-vehicle time and the deceleration of a driver, and the parameter thereof is adjusted on the basis of the measured data so as to coincide with the driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle running control device, and more particularly to a speed control and an alarm control when the vehicle follows a preceding vehicle.

[0002]

2. Description of the Related Art Conventionally, various traveling control devices have been developed for the purpose of reducing the driving operation of a vehicle driver and further improving safety in traveling on a highway.

For example, in a vehicle collision warning device disclosed in Japanese Patent Laid-Open No. 59-105587, a vehicle speed and a relative speed at the time of generating a brake signal are latched, and a predetermined value read from a storage device at the time of generating a brake signal. A configuration is shown in which the warning distance is compared with the inter-vehicle distance when the brake signal is generated, and the predetermined warning distance is rewritten based on the comparison result. That is, the inter-vehicle distance L when the brake signal is generated
And a predetermined warning distance LA determined based on the own vehicle speed and the relative speed, and when LA <L, a predetermined value is added to the predetermined distance LA, while when LA> L, a predetermined warning distance LA is added. The alarm distance is rewritten by subtracting a constant value from. As a result, the warning distance is automatically rewritten according to the timing at which the driver steps on the brake, and the warning that matches the braking timing of the driver is generated.

Further, in the inter-vehicle distance control device disclosed in Japanese Patent Laid-Open No. 61-77533, there is shown a configuration for controlling the own vehicle speed so that the inter-vehicle distance becomes a safe inter-vehicle distance calculated according to the own vehicle speed. ing.

[0005]

As described above, a device for controlling the traveling by controlling the timing of the alarm and the own vehicle speed has been proposed in the past. However, the driving characteristics such as the timing of the brake operation are different for each driver. It is not easy to perform vehicle speed control and alarm control that match the driving sensation of each driver, because the driving characteristics of the vehicle vary depending on the driving situation. In particular, in semi-automatic driving where the vehicle automatically controls the throttle and brake and the driver controls the steering, unlike fully automatic driving where the driver is completely released from driving, the throttle that matches the driver's operation interval is used. When the driver's sense of danger and excessive alarms are frequently generated, the reliability of the driver's system is deteriorated.

In Japanese Patent Laid-Open No. 59-105587, the predetermined warning distance is adjusted to be increased or decreased according to the braking timing of the driver, but the adjustment is achieved by adding or subtracting a certain value. This is not enough to give an optimum warning distance according to various driving situations.

The present invention has been made in view of the above-mentioned problems of the prior art, and traveling control capable of performing vehicle speed control and warning control at optimum timing according to the driving characteristics and traveling conditions of each driver. To provide a device.

[0008]

In order to achieve the above object, a vehicular traveling control device according to a first aspect of the present invention comprises an inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle, and a vehicle speed detecting means. Based on the relative speed detecting means for detecting the relative speed with respect to the preceding vehicle, based on the inter-vehicle distance, the own vehicle speed and the relative speed, the deceleration start inter-vehicle distance for following the preceding vehicle under constant deceleration conditions is determined by a predetermined driver model formula. It is characterized by having a calculating means for calculating and a controlling means for controlling the traveling of the own vehicle on the basis of the deceleration start inter-vehicle distance calculated by the calculating means.

In order to achieve the above object, the vehicle travel control device according to claim 2 is the vehicle travel control device according to claim 1, wherein the control means is based on the deceleration start inter-vehicle distance. It is characterized by controlling the timing of alarm generation.

In order to achieve the above object, the vehicle drive control device according to a third aspect of the present invention is the vehicle drive control device according to the first or second aspect, further comprising personal parameters of the driver model formula. Is provided on the basis of the statistical values of the inter-vehicle distance, the own vehicle speed, and the relative speed at the time of the driver's deceleration operation.

In order to achieve the above object, the vehicle drive control device according to a fourth aspect is the vehicle drive control device according to the first or second aspect, further comprising a personal parameter of the driver model formula. Is provided based on the average inter-vehicle time before the driver's deceleration operation.

In order to achieve the above object, the vehicle drive control device according to a fifth aspect of the present invention is the vehicle drive control device according to the first or second aspect, further comprising personal parameters of the driver model formula. Is provided based on the brake pressure at the time of the deceleration operation of the driver and the inter-vehicle time at the time of the completion of the deceleration operation.

In order to achieve the above-mentioned object, a vehicle running control device according to a sixth aspect of the invention is a vehicle running control system according to the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect. The device further includes second computing means for calculating a deceleration start inter-vehicle distance for following the preceding vehicle under a constant deceleration time condition based on the inter-vehicle distance, the own vehicle speed, and the relative speed, and a driver, The selection means selects the deceleration start inter-vehicle distance calculated by the calculation means or the second calculation means in accordance with the driving characteristics of the above.

Further, in order to achieve the above object, the vehicle running control device according to claim 7 is a vehicle running control device according to claim 1 or claim 2 or claim 3 or claim 4 or claim 5. The device further includes second computing means for calculating a deceleration start inter-vehicle distance for following the preceding vehicle under a constant deceleration time condition based on the inter-vehicle distance, the own vehicle speed, and the relative speed, and a driver, The selection means selects the deceleration start inter-vehicle distance calculated by the calculation means or the second calculation means according to the degree of freedom of the driving task.

[0015]

In the vehicle running control device according to the first aspect, the deceleration start inter-vehicle distance for following the preceding vehicle under constant deceleration is calculated by a predetermined driver model formula, and the vehicle deceleration start inter-vehicle distance is calculated based on the deceleration start inter-vehicle distance. Control the driving of the car.

The driver model formula, which is the basic concept of the present invention, will be described in detail below.

In considering at what timing the driver traveling following the preceding vehicle of the driver model performs the deceleration operation, first, the following situation is assumed. That is, both the preceding vehicle and the host vehicle perform steady follow-up traveling at a constant speed V ₀ (relative speed 0).

At time t = 0, the preceding vehicle starts decelerating at a constant deceleration G ₀ and stops.

At time t = t _d , the follower (own vehicle) starts decelerating at the same deceleration G ₀ as the preceding vehicle and stops.

FIG. 2 shows changes in vehicle speed between the preceding vehicle and the subject vehicle (following vehicle) in such a situation. In FIG. 2, the horizontal axis represents time t and the vertical axis represents vehicle speed V. In addition, in the figure, the dotted line indicates the vehicle speed change of the preceding vehicle, and the solid line indicates the vehicle speed change of the host vehicle (following vehicle). The area of the shaded area in the figure is the distance ΔH at which the subject vehicle (following vehicle) approaches the preceding vehicle before both vehicles stop. This Δ
H is

[Equation 1] Given by. Here, in the case where the preceding vehicle starts decelerating while traveling at the inter-vehicle distance H, when it is considered that the following vehicle will decelerate exactly the same as the preceding vehicle, in order for the following vehicle to stop without colliding with the preceding vehicle,

[Equation 2]

(Equation 3) It is necessary that the condition of is satisfied. The left side of equation (3) is a value obtained by dividing the inter-vehicle distance by the vehicle speed, that is, the so-called inter-vehicle time,
Expression (3) indicates that the following vehicle needs to start deceleration with a delay time shorter than the value of the inter-vehicle time. That is,
Inter-vehicle time is defined as the margin time when a preceding vehicle starts decelerating / approaching and the following vehicle starts decelerating within that time and can stop without collision if it decelerates at the same deceleration as the preceding vehicle. be able to. If the driver is following the preceding vehicle and expects that the same deceleration as that of the preceding vehicle is possible under normal driving conditions, the driver can It can be considered that the driving operation is performed so that the time (that is, the margin time) does not become shorter than a certain value. Therefore, in the present invention, this inter-vehicle time is hereinafter referred to as a limit inter-vehicle time. In conclusion, it can be considered that the driver starts the deceleration operation so that the inter-vehicle time becomes less than the limit inter-vehicle time.

On the other hand, when the absolute value of the relative speed is already large, the driver starts deceleration operation before the inter-vehicle time reaches the limit inter-vehicle time, and when the limit inter-vehicle time is reached, the relative speed is changed. It is considered that the vehicle will decelerate to zero. Now, assume this situation as follows.

The preceding vehicle runs at a vehicle speed V _t0 and the following vehicle runs at a constant speed V _f0 .

The following vehicle starts decelerating at a constant deceleration G _f at time t = 0.

FIG. 3 shows the vehicle speed changes of the preceding vehicle and the following vehicle in this case. The area of the shaded area is the distance ΔH that the following vehicles approach until the relative speed becomes zero after the following vehicle starts decelerating. ΔH is

[Equation 4] Given by.

From the above consideration, the driver starts the deceleration operation when the absolute value of the relative speed is large,
When the deceleration operation is performed so that the relative speed becomes 0 when the limit inter-vehicle time is reached, the inter-vehicle distance H _{B at} which the driver starts the deceleration operation is the sum of the equations (1) and (4). ,

(Equation 5) Alternatively,

(Equation 6) Becomes In equations (5) and (6), H _lim = t
_d : limit inter-vehicle time, V _f : own vehicle speed, V _r : relative speed. The equations (5) and (6) are predetermined driver model equations, and the calculating means in the present invention is the equations (5) and (6).
The deceleration start inter-vehicle distance H _B is calculated based on the above, and traveling control is performed.

The driver model formulas (5) and (6) obtained from such theoretical consideration accurately reflect the actual deceleration operation timing of the driver, as will be shown in the embodiments described later. By performing control based on this driver model formula, it becomes possible to perform traveling control that matches the actual driving feeling of the driver.

According to another aspect of the vehicle travel control device of the present invention,
In particular, the control means controls the alarm generation timing based on the deceleration start inter-vehicle distance. When the deceleration start inter-vehicle distance is reached, the deceleration operation should be performed in normal driving operation.However, if the deceleration start inter-vehicle distance is reached but the deceleration operation is still not performed, an alarm is generated. By doing so, it is possible to give an alarm at an optimal timing that matches the driving feeling of the driver.

In the vehicle travel control device according to any one of claims 3 to 5, the individual parameters represented by the driver model equations (5) and (6), that is, the limit inter-vehicle time _Hlim and the reduction of the individual parameters are different. A device for adjusting the speed G _f is provided. According to the third aspect of the present invention, the values of these individual parameters are adjusted by the statistical processing of the actual driver data. In the invention according to claim 4,
It is adjusted based on a predetermined relationship between the personal parameter and the average inter-vehicle time before deceleration operation by the driver. Further, in the invention according to claim 5, the value of the individual parameter is adjusted based on the relationship between the individual parameter and the brake pressure and the actually measured value of the individual parameter.

In the inventions according to claims 6 to 7, two driver model expressions are used, and one of the driver model expressions is used in accordance with the driver or the driving situation, that is, the degree of freedom of the driving task of the driver. The travel control is performed using the deceleration start inter-vehicle distance. One of the two driver model expressions is a driver model under the constant deceleration condition described above, and the other is a driver model expression under the constant deceleration time condition. As already known, the driver model formula under constant deceleration time conditions is

(Equation 7) Given by. In the equation (7), τ is an estimated time from the present time, and a is a relative deceleration of the preceding vehicle with respect to the own vehicle. The vehicle driver or even the same driver determines whether to perform deceleration operation under constant deceleration conditions or deceleration operation under constant deceleration time, depending on the driving situation, that is, the degree of freedom of the driving task. By calculating the deceleration start inter-vehicle distance using any one of the driver model formulas, optimum traveling control can be performed according to each driver and various traveling situations.

The effectiveness of the driver model formula used in the present invention will be further clarified by referring to the following examples.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 is a block diagram showing the configuration of this embodiment. An inter-vehicle distance sensor 10 such as a laser beam or a millimeter wave is provided at a predetermined position of the vehicle to detect an inter-vehicle distance with a preceding vehicle. Also,
A vehicle speed sensor 12 is also provided to detect the speed of the host vehicle.
The detection signals of the inter-vehicle distance sensor 10 and the vehicle speed sensor 12 are
It is output to the control unit ECU 14. Control unit ECU14
Is composed of a CPU, a memory, an I / O interface, etc., and performs a process described later to output a control signal to the actuators 16 and 18, the display 24, and the speaker 26. The actuator 16 controls ON / OFF of the brake 20 based on the control signal from the ECU 14, and the actuator 18 controls opening / closing of the throttle 22 based on the control signal from the ECU 14. Also, the display 24
Outputs an alarm or the like based on the control signal from the ECU 14, and the speaker 26 outputs an alarm sound or the like based on the control signal from the ECU 14.

Here, the control unit ECU 14 stores a predetermined driver model formula (6) in the memory, and the CPU outputs a control signal based on the driver model formula (6).
Incidentally, in the expression (6), parameters specific to the driver (individual parameters) is the limit time headway H _lim and deceleration G _f, these individuals parameters in accordance with the operating characteristics and traveling conditions of the driver It is adjusted appropriately.

FIG. 4 shows the brake timing when the vertical axis is (vehicle distance / vehicle speed) and the horizontal axis is (relative speed) ² / vehicle speed for the seven drivers obtained by the applicant's experiment. An example of the measured value of is shown. As is clear from the definition, the vertical axis of FIG. 4 is H _B / V _f on the left side of the equation (6),
The horizontal axis is (V _r ² / V _f ) on the right side of the equation (6). FIG.
(A) to (g) are the actual measurement results of each of the seven drivers, and the straight line in the figure is the straight line shown by the equation (6) and is obtained by linear regression of each data. The slope (1/2 G _f ) and intercept (H _lim ) of these straight lines and the root mean square of the estimation error are obtained as shown in FIG. From these results, all the straight lines shown in FIG. 4 are in good agreement with the actual measurement data, indicating that the braking start inter-vehicle distance is represented by the equation (6).

Therefore, the parameter H _lim depends on the driver.
By adjusting G and G _f to the optimum values, it is possible to accurately evaluate the driver's normal braking start inter-vehicle distance, and it becomes possible to perform vehicle speed control and alarm control based on this. Is understood.

Further, engine braking by throttle off is considered to be a deceleration with a constant deceleration, which is weaker than the foot brake. Therefore, not only the starting of braking but also the timing of accelerator OFF (throttle OFF) is expressed by equation (6). It is believed that Therefore, the driver's throttle OFF timing and brake ON timing are H _lim and G _f (1 /
2G _f ) is a parameter and is expressed by a linear line,
By comparing this equation with the actual travel data, it becomes possible to perform throttle control, brake control, alarm control, etc. that match the driving feeling of the driver.

The applicant of the present application compares the timing of the driver's throttle OFF and brake ON with the formula (6) based on the actual traveling data, and as a result, the driver brakes only with the throttle OFF. The probability that the driver model formula (6) was the same when the deceleration due to is not achieved is about 85%, and when the driver turns on the brake, the driver model formula (6) also applies braking within an error of 1 second. The probability of reaching was about 77%. Therefore, from this data, the actual driving operation of the driver (throttle OFF,
It has been confirmed that the timings of the brake ON), the driver model equation (6), the throttle OFF, and the brake ON are in good agreement.

The ECU 14 will be described below with reference to the flowchart.
The control process in 1 will be described in more detail and specifically.

FIG. 7 shows a processing flow chart when the driver model equation (6) is applied to the inter-vehicle distance control (following traveling). In FIG. 7, first, the vehicle speed V _f ,
The relative speed V _r and the inter-vehicle distance L are detected (S101).
The relative speed V _r may be calculated by time differentiation of the inter-vehicle distance L obtained by the inter-vehicle distance sensor 10, or may be directly detected by using the Doppler effect. Next, the target inter-vehicle distance L _T with respect to the preceding vehicle at the time of following traveling is calculated and set (S102). The target inter-vehicle distance L _T may be a value input by the vehicle driver, or may be the inter-vehicle distance at the time when the driver selects the transition to the following traveling mode. Then, the current inter-vehicle distance L and the target inter-vehicle distance L
The difference ΔL of _T is calculated (S103) and compared with a predetermined value L _m (for example, −2 m) in magnitude (S104). This predetermined value has a meaning as an allowable error with respect to the target inter-vehicle distance, and by changing the predetermined value L _{m according} to the current inter-vehicle distance L, smooth control becomes possible. For example, it is possible to set L _m = − (K · L + L ₀ ) instead of the fixed value −2 _m .

As a result of the comparison in S104, if ΔL <L _M , it means that the current inter-vehicle distance L is shorter than the target inter-vehicle distance L _T , so it is necessary to perform deceleration operation, and the ECU
14 calculates the braking start distance H _B using the driver model formula of the formula (6) (S105). The values detected in S101 are used for the vehicle speed V _f and the relative speed V _r , and the individual parameters H _lim and 1/2 G are used.
_The value stored in the memory is used as _f , for example, H _lim =
Values such as 0.54, 1/2 G _f = 0.47 are used.
Since these parameters are individual characteristic values, it is necessary to appropriately adjust them by learning or the like so as to match the driver and running conditions, but here, for the sake of convenience, fixed values are used. After the braking start distance H _B is calculated in this way, the ECU 14 compares the current inter-vehicle distance L with the calculated braking start distance H _B (S106), and the current inter-vehicle distance L starts braking. Distance H
If it is shorter than _B , the throttle flag ACC is turned off and the brake flag BRK is turned on (S1
07), vehicle speed control is performed (S108). That is, in this case, the throttle is fully closed, the brake is turned on, and the vehicle is automatically decelerated at a constant deceleration. On the other hand, when the current inter-vehicle distance L is longer than the braking start distance H _B ,
Then calculates the throttle-off starting distance H _a (S11
3). This calculation is also performed using the driver model formula (6), and as the personal parameter, for example, H _lim = 0.7
0, 1/2 G _f = 1.30 is used. The comparison between the current inter-vehicle distance L and the throttle-off start distance H _a is performed (S114), the brake flag with current following distance is shorter than the throttle-off start distance H _a is the throttle flag ACC and OFF BRK is turned off (S115), and vehicle speed control is performed (S108). That is, the brake remains OFF, but the throttle is turned to O.
Start deceleration as FF. Also, when the current inter-vehicle distance L is longer than the throttle-off start distance H _a, the target vehicle speed V
_ft is decreased by ΔV (S116), the throttle flag ACC is turned on, and the brake flag BRK is turned off.
Then, the vehicle speed is controlled similarly (S108).

On the other hand, in S104, the difference ΔL is the predetermined value L _M
If it is larger, the difference ΔL and the predetermined value L _P are further compared in size (S109). This predetermined value L _P is a value that means an allowable error like L _M, and can be set to +2 m, for example, or can be determined according to the current inter-vehicle distance L. Note that L _M is −2 m and L _P is +2 m
In the case of, it means that follow-up control is performed with an error of ± 2 m. As a result of the comparison of the difference ΔL and the predetermined value L _P , if ΔL is larger than L _P , the target inter-vehicle distance L
_{Since the} current inter-vehicle distance L is longer than _T , acceleration operation is required. Therefore, the target vehicle speed V _ft has a constant value Δ
V is added (S110) and the throttle flag ACC is turned on.
And the brake flag BRK is turned off (S11
1), vehicle speed control is performed (S108). That is, the throttle is controlled to open so as to reach the target vehicle speed and the vehicle is accelerated. Further, when the difference ΔL is smaller than the predetermined value L _P, it means that the current inter-vehicle distance L matches the target inter-vehicle distance L _T within the allowable error range. Therefore, the throttle flag ACC is turned on and the brake is applied. Turn off the flag BRK (S
112), the vehicle speed is controlled to maintain the current state (S10).
8).

As described above, the driver's model equation (6) is used to calculate the braking start distance H _B and the throttle-off start distance H _a of the driver, and the magnitude is compared with the current inter-vehicle distance L to determine the throttle and brake. By controlling the vehicle speed control, the vehicle speed control can be performed at the timing that the driver would normally perform, and smooth vehicle speed control that matches the driver's driving sensation and that does not feel uncomfortable can be performed.

In the present embodiment, the case where the vehicle speed is controlled has been described as an example, but the alarm flag ON / OFF is controlled according to the driver model formula to control the alarm output of the display 24 or the speaker 26. It is also possible to do so. In this case, the alarm is issued at a timing that matches the driver's driving sensation, so that it is possible to prevent unnecessary stress on the driver.

Further, although the individual parameters H _lim and G _f are set to constant values in the present embodiment, as described above, these parameters are optimum values according to the driver and the driving situation (degree of freedom of driving task). Need to be adjusted. Less than,
A method of adjusting personal parameters will be described.

<First Adjustment Method> FIG. 8 shows a processing flow chart for adjusting individual parameters. The principle of the adjustment in this processing is that the parameters (H _limb , G
_fb ) and parameters (H _limt , G _ft ) that define the throttle OFF timing are taken in and learned during actual traveling. In FIG. 8, first throttle OFF
Clear timing counter N _a and the counter N _b brake ON timing (S201), vehicle speed V _f and inter-vehicle distance L, to detect the relative velocity V _r (S202).
The relative velocity V _r is positive when the distance is far. Next, in order to avoid unnecessary learning in inappropriate driving situations (when throttle-off and braking-on are performed within a short time (for example, within 1 second)), the preceding vehicle is approaching at a speed higher than a predetermined speed. Or not. That is, it is determined whether or not V _r <0 and V _f ≧ V _f0 (V _f0 is, for example, 20 km / h) (S203). If this condition is satisfied, then it is determined whether or not the throttle has been changed from ON to OFF (S204). If the throttle is ON at the time of the previous processing and the throttle is OFF at the time of this processing, it is determined that the driver has operated the throttle OFF at this time, and L / V _f and V _r ² / V _f is calculated (S205). Note that these correspond to the physical quantities on the vertical axis and the horizontal axis in FIG. Then, the throttle OFF timing counter N _a is incremented by 1 (S20
6) It is determined whether the counter value N _a is equal to or greater than the predetermined value N _a0 (S207). When the actual measurement data during the actual traveling can be acquired more than the predetermined value, the individual parameters H _limt and 1/2 G _ft are calculated based on these data (S208) and stored in the memory and the throttle O
Again is cleared to 0, the FF timing for the counter N _a (S209). The number of actual data for calculating the individual parameter can be set to 50 or more, for example. Further, for the personal parameter calculation processing in S208, for example, the least squares method can be used.

On the other hand, the individual parameter defining the brake ON timing can be calculated by the same process, and S
When NO is determined in 204 (except when throttle off and brake on are performed within a short time (for example, within 1 second) or in the deceleration time constant mode described later)
First, it is determined whether or not the brake has changed from OFF to ON (S210). Brake off by previous process
If it is turned on in this process, it is determined that the driver has operated the brake for the first time, and L / V _f , V _r ²
/ V _f is calculated (S211), the counter N _b is incremented by 1 (S212), and it is determined whether a predetermined number of data has been acquired (S213). When a predetermined number or more of actual data are acquired, the individual parameter H _limb , 1/2 is obtained by using the actual data and the least square method.
G _fb is calculated (S214), stored in the memory, and the counter N _b is cleared to 0 (S215).

As described above, by calculating the individual parameter by using the own vehicle speed data, the relative speed data, and the inter-vehicle distance data at the timing when the driver turns the throttle OFF or the brake ON during the actual traveling. The driver model equation (6) peculiar to the driver can be determined, and control matching the driving feeling can be performed.

In FIG. 8, the individual parameters were calculated using a predetermined number of the obtained actual data. However, in order to improve the reliability of the data, only the data whose L / V _f is within the predetermined range is used. It is also possible to adopt a configuration in which personal parameters are calculated. In this case, it becomes possible to more accurately determine the driver model equation (6) of the driver during normal driving.

At the stage where the number of data required to calculate the individual parameters is not reached, H _limt = 0.70, 1/2 G _ft as an average value as shown in FIG.
= 1.30, H _limb = 0.54, 1 / 2G _fb = 0.47
A value of the degree can be used, or a value learned in the previous run can be stored in a memory and the value can be used.

<Second Adjustment Method> FIGS. 9 to 11 show a second method for adjusting individual parameters. FIG. 9 shows the relationship between the average inter-vehicle time T _ave before the deceleration operation and the limit inter-vehicle time H _lim . Limit inter-vehicle time H
_It can be seen that a driver with a short _lim has a short average inter-vehicle time T _{ave and} is in a substantially proportional relationship. That is,

## EQU8 ## H _lim = 0.5T _ave (8). Therefore, the limit inter-vehicle time H _lim can be indirectly determined by measuring the average inter-vehicle time T _ave .

FIG. 10 shows the relationship between the limit inter-vehicle time H _lim and _½ G _f of the seven drivers shown in FIG. It can be seen that the driver 5 and the driver 7 are located on substantially the same straight line. This line is

[Equation 9] 1 / 2G _f = -1.156H _lim +1.022 (9), and if the limit inter-vehicle time is determined by this,
This means that the deceleration is also determined automatically. Therefore, based on these equations, the ECU 14 measures H _lim and 1/2 G _f by measuring only the average inter-vehicle time T _ave.
Can be adjusted together.

FIG. 11 shows a concrete flowchart of the adjustment processing based on the above principle. In FIG. 11, first, the own vehicle speed V _f and the current inter-vehicle distance L are detected (S
301). Then, in order to remove unnecessary data, the brake is changed from OFF to ON, there is a preceding vehicle, and the own vehicle speed V
It is determined whether or not _f is a predetermined value V _f0 or more (S30
2) If this condition is satisfied, the inter-vehicle time L / V _f is calculated and sequentially integrated, and the data number N is incremented by 1 (S303). When the number of inter-vehicle time data becomes equal to or more than the predetermined value N ₀ (S304), the average inter-vehicle time T _ave is calculated (S305), and the limit inter-vehicle time H _lim is determined based on the average inter-vehicle time T _ave ( S306). This determination is made by the equation (8) as described above. Then, the deceleration 1/2 G _f is determined by the equation (9) based on the limit inter-vehicle time H _lim (S307). After the individual parameters are determined, T and N are cleared (S308) to prepare for the next process.

As described above, according to this method, the individual parameter can be determined only by measuring the average inter-vehicle time T _ave , so that the driver model formula is determined more easily than the first method described above, and the driver model is determined. It is possible to perform control adapted to.

As can be seen from FIG. 10, the driver 5
And the driver 7 is not adapted to the determination of personal parameters by this method. That is, the driver 5 has a larger average inter-vehicle time and a larger value of the limit inter-vehicle time H _lim than other drivers (0.834). The deceleration calculated from this value using the above equation (9) is 0.058, but the actual deceleration value of the driver 5 is 0.480 as shown in FIG.
Is. Therefore, when the absolute value of the relative velocity is large,
The inter-vehicle distance for starting braking according to the driver model is shorter than the inter-vehicle distance for actually starting braking by the driver 5. However, the driver 5 originally has a long average inter-vehicle time and is following with a sufficient margin, and it is considered that no great discomfort occurs even if the braking timing of the driver model is slightly delayed. vice versa,
The driver 7 has smaller individual parameters than the other drivers. The deceleration estimated from the limit inter-vehicle time H _lim becomes larger than the actual value of the driver 7,
When the absolute value of the relative speed is large, the braking start inter-vehicle distance by the driver model becomes longer than the inter-vehicle distance at which the driver 7 actually starts braking. However, this means that the vehicle speed control and the alarm control occur on the safer side (in the direction in which the inter-vehicle distance becomes longer), and therefore, it is considered that there is no great discomfort.

<Third Adjustment Method> Two methods for adjusting individual parameters have been described above, but it is also conceivable to directly measure and adjust individual parameters. That is, 1/2 G _f may be determined using the deceleration converted from the brake pressure when the driver operates the brake, and H _lim may be calculated from the minimum value of the inter-vehicle distance from the preceding vehicle. Even in this case, in order to improve reliability, it is preferable to avoid unnecessary learning as in the first adjustment method described above and use an average value of the measured brake pressures.

Second Embodiment In the above-described first embodiment, an example in which a driver model under a constant deceleration condition is determined and vehicle speed control and alarm control are performed according to this driver model has been shown. Depending on the driving situation (degree of freedom of the driving task), the same driver may perform deceleration operation not under constant deceleration but under constant deceleration time. In the present embodiment, in view of such a situation, an example in which further adaptive control is enabled by appropriately selecting the driver model will be described.

FIG. 12 shows two types of deceleration operation. FIG. 12 (A) shows a constant deceleration type shown in the first embodiment, that is, a type in which deceleration is constant and deceleration is controlled by controlling deceleration time. FIG. 12 (B) shows a constant deceleration time. In other words, the deceleration time is constant and the deceleration is controlled by controlling the deceleration. It is considered that the driver who performs relatively smooth driving is of the constant deceleration type, and the driver who performs comparatively crisp driving is of the constant deceleration time type. In addition, even if the same driver performs general deceleration or low traffic volume, or when the preceding vehicle performs a gentle deceleration, that is, when the degree of freedom of the driving task is large, deceleration constant deceleration is performed, It is considered that the deceleration time becomes constant when there is an interrupting vehicle or a large following vehicle behind the vehicle, or when the preceding vehicle performs a rapid deceleration, that is, when the degree of freedom of the driving task is small. The ECU 14 in the present embodiment determines whether the current driver or running condition is a constant deceleration type or a constant deceleration time type, and applies a driver model corresponding to each deceleration type to perform vehicle speed control or alarm control. To do. The constant deceleration type driver model can be expressed by the equation (6) as described above. On the other hand, the driver model with a constant deceleration time is, for example, "Development of Collision Avoidance System" by Hashimoto et al.
As detailed in

Equation 10] _{H B = V r τ + aτ} 2/2 + is that represented by H _lim V _f (10) are known. In addition, a is a deceleration relative to the vehicle speed of the preceding vehicle, and H _lim is a limit inter-vehicle time. The ECU 14 stores these model formulas in a memory, calculates the limit inter-vehicle distance using any one of the model formulas according to the driver or the traveling situation, and performs vehicle speed control or alarm control by comparing with the current inter-vehicle distance.

FIG. 13 shows a more detailed and specific processing flowchart of the ECU 14 in this embodiment. In the process of FIG. 13, the length of the brake ON time is used as a parameter for identifying both driver models.

In FIG. 13, first, the own vehicle speed V _f and the current inter-vehicle distance L are detected (S401). Then, it is determined whether or not a preceding vehicle exists and the vehicle speed is equal to or higher than a predetermined value (S
402), if the condition is satisfied, it is further determined whether or not the brake is operated (S403). When the brake is operated, the brake pressure _Pb is detected (S4
14) and compare with the value of the maximum brake pressure memory N _b (S4
15), it is greater than the value of N _b to N _b stores P _b (S416). On the other hand, when the brake is not operated, N _b and the predetermined value N _b0 are compared in magnitude (S405), and when the predetermined value is not reached, N _b is cleared as unnecessary data (S413) and the predetermined value is set. If it has, N _b
Is stored in the N _c th position of the array T _{B in} the memory and N _c
The counts up, clearing the maximum brake pressure memory N _b (S406). Then the number N _c of the maximum brake pressure that is stored in the memory it is determined whether or not reached a predetermined value (e.g., five) (S407), when it reaches the N _c standard for this maximum brake pressure N _b The deviation S _Tb is calculated (S40
8). When the standard deviation S _Tb is equal to or _larger than the predetermined value, it is determined that the operation is not the constant deceleration type operation, and the deceleration time is constant and the deceleration is controlled. On the other hand, when the standard deviation is less than or equal to the predetermined value, the deceleration is constant and the deceleration time is controlled (S
409, S410, S411).

In this way, when the deceleration constant type or the deceleration time constant type is determined based on the brake ON time,
Based on these driver model equations, the ECU 14 calculates a brake-ON inter-vehicle distance or a throttle-OFF start distance and compares it with the current inter-vehicle distance to perform vehicle speed control or alarm control.

In this embodiment, both driver models are alternatively selected according to the brake ON time, but it is also possible to selectively use both driver models by detecting the maximum brake pressure. It is also possible to use both brake pressures. Further, not limited to these physical quantities, it is possible to use any other physical quantity considered effective for identifying both driver models. An effective parameter for identifying both driver models is an amount that reflects the driving characteristics of the driver or an amount that reflects the degree of freedom of the driving task of the driver (for example, the type of rear vehicle or a sudden change in the inter-vehicle distance, driving When the frequency of operation is high (for example, when the frequency of the throttle opening waveform and the brake pressure waveform is high), for example, 1.0
sec and the average vehicle speed are short) may be used.

FIG. 14 shows a processing flowchart when the driver model selection processing shown in FIG. 13 is particularly used for alarm control. In addition, in this processing flowchart, considering that both driver models are changed according to the traveling situation (degree of freedom of the driving task of the driver),
It shows a case where the braking start distance is calculated in advance using both driver models and the alarm control is performed by comparing these with the current inter-vehicle distance. That is, as described above, the deceleration constant type deceleration model is applied when general driving or moderate deceleration of the preceding vehicle occurs, and when deceleration or sudden deceleration of the preceding vehicle occurs, the deceleration time constant type is applied. The deceleration model is applied. Therefore, both driver models are effectively used at different times by issuing a temporary alarm (initial alarm) using the constant deceleration model and a secondary alarm (collision alarm) using the constant deceleration time model. It is a thing.

Specifically, first, the vehicle speed V _f and the relative speed V
_r , the current inter-vehicle distance L is detected (S501), and the brake start distance _Hw1 is calculated using a constant deceleration type driver model (S502). Then, the current inter-vehicle distance L and H _w1 are compared in size (S503), and if the current inter-vehicle distance is smaller than the brake start inter-vehicle distance H _w1 based on the constant deceleration model, the temporary warning flag W1 is turned on (S504). If the current inter-vehicle distance L is greater than the inter-vehicle distance H _{w1 due} to the brake opening, the temporary warning flag W1 is turned off (S509).
Next, the brake start distance _Hw2 is calculated based on the constant deceleration time driver model formula (S505), and the magnitude is compared with the current inter-vehicle distance to set the secondary warning flag W2. That is, the current inter-vehicle distance L is equal to the braking start inter-vehicle distance H.
If it is smaller than _w2 , the temporary warning flag W1 is turned off and the secondary warning flag W2 is turned on (S50
7) If the current inter-vehicle distance L is greater than the brake start inter-vehicle distance H _w2 , the secondary warning flag W2 is turned off (S5
10) The alarm output of the display 24 or the speaker 26 is controlled based on these flags (S50).
8). Therefore, the current inter-vehicle distance is smaller than H _w1 and H _w2
When it is larger than the above, a temporary alarm is output, and when the current inter-vehicle distance is smaller than H _{w2, a} secondary alarm is output. As a result, an alarm is given at normal deceleration timing (under constant deceleration) during normal driving, and in the event of an interruption or sudden deceleration of a preceding vehicle, an alarm is issued at deceleration timing in the constant deceleration time mode. Will be output, and it becomes possible to give an alarm at the optimum timing that matches the traveling situation.

In the present embodiment, both driver models are used in advance to calculate the brake start inter-vehicle distance, and the inter-vehicle distance and the current inter-vehicle distance are compared in size.
According to the process of FIG. 13, first, one of the two driver models is selectively selected in accordance with the driving situation, the brake start inter-vehicle distance is calculated based on the selected driver model, and the magnitude is compared with the current inter-vehicle distance. Gives the same result.

Further, in the first and second embodiments, the vehicle speed control is performed by opening and closing the throttle.
In a vehicle equipped with a diesel engine, the vehicle speed can be controlled by controlling the fuel injection amount instead of controlling the opening / closing of the throttle.

[0066]

As described above, according to the vehicle travel control device of the first to seventh aspects, the vehicle speed control and the alarm control can be performed at the timing that matches the driving feeling of the driver. Therefore, it is possible to maintain comfortable and smooth running without giving the driver an unpleasant sensation or discomfort.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of driver model calculation in the embodiment.

FIG. 3 is an explanatory diagram of driver model calculation in the embodiment.

FIG. 4 is a graph showing a relationship between actual measurement data of a plurality of drivers and a driver model.

FIG. 5 is an explanatory diagram of individual parameters of the driver shown in FIG.

FIG. 6 is an explanatory diagram of a driver model when the brake is on and when the throttle is off in the embodiment.

FIG. 7 is a processing flowchart in the embodiment.

FIG. 8 is a processing flowchart in the embodiment.

FIG. 9 is a graph showing another method of adjusting individual parameters in the embodiment.

FIG. 10 is a graph showing the relationship of individual parameters in the same example.

FIG. 11 is a processing flowchart showing a method for adjusting individual parameters in the embodiment.

FIG. 12 is an explanatory diagram of two driver models.

FIG. 13 is a processing flowchart in another embodiment of the present invention.

FIG. 14 is a processing flowchart of alarm control in another embodiment.

[Description of Reference Signs] 10 inter-vehicle distance sensor 12 vehicle speed sensor 14 control unit ECU 16, 18 actuator 20 brake 22 throttle 24 display 26 speaker

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiyuki Hashimoto 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Katsuhiro Asano 1 in 41, Yokoshiro, Nagakute-cho, Aichi-gun, Aichi Toyota Central Research Institute Co., Ltd. (72) Inventor Yoshikazu Hattori 1 of 41 Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture

Claims (7)

[Claims] 1. An inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle, an own vehicle speed detecting means, a relative speed detecting means for detecting a relative speed to the preceding vehicle, an inter-vehicle distance, an own vehicle speed and a relative speed. Based on the deceleration start inter-vehicle distance based on the deceleration start inter-vehicle distance calculated by the calculation means, the vehicle travels based on the deceleration start inter-vehicle distance based on the predetermined driver model formula for following the preceding vehicle under constant deceleration conditions. A vehicle travel control device comprising: 2. The vehicle travel control device according to claim 1, wherein the control unit controls an alarm generation timing based on the deceleration start inter-vehicle distance. 3. The vehicle travel control device according to claim 1, further comprising: statistics of the inter-vehicle distance, the own vehicle speed, and the relative speed when the driver decelerates the personal parameters of the driver model equation. A travel control device for a vehicle, comprising: an adjusting unit that adjusts based on a value. 4. The vehicle travel control device according to claim 1 or 2, further comprising adjusting means for adjusting the personal parameter of the driver model formula based on an average inter-vehicle time before deceleration operation by the driver. A travel control device for a vehicle, comprising: 5. The vehicle travel control device according to claim 1 or 2, wherein the personal parameters of the driver model formula are a brake pressure during deceleration operation of a driver and an inter-vehicle time after completion of deceleration operation. A travel control device for a vehicle, comprising: an adjusting means for adjusting based on the above. 6. Claim 1 or claim 2 or claim 3.
Alternatively, in the vehicle travel control device according to claim 4 or 5, further, based on the inter-vehicle distance, the own vehicle speed, and the relative speed, a deceleration start inter-vehicle distance for following the preceding vehicle under a constant deceleration time condition is set to a predetermined value. A second calculation unit that calculates by a driver model formula; and a selection unit that selects the deceleration start inter-vehicle distance calculated by the calculation unit or the second calculation unit according to the driving characteristics of the driver. Vehicle drive control device. 7. Claim 1 or claim 2 or claim 3.
Alternatively, in the vehicle travel control device according to claim 4 or 5, further, based on the inter-vehicle distance, the own vehicle speed, and the relative speed, a deceleration start inter-vehicle distance for following the preceding vehicle under a constant deceleration time condition is set to a predetermined value. A second calculation means calculated by a driver model formula; and a selection means for selecting the deceleration start inter-vehicle distance calculated by the calculation means or the second calculation means according to the degree of freedom of the driving task of the driver. A vehicle travel control device characterized by: