JP2000118369A - Vehicle travel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle travel control device reducing the amount of a driver's operation to enhance vehicle safety and impart incongruous feeling to the driver. SOLUTION: An intervehicular distance detecting part 2 detects an intervehicular distance and a vehicle speed sensor 3 detects the speed of a vehicle and an accelerator opening sensor 4 detects throttle valve opening. A computing process part 1 calculates relative speeds and the acceleration of the vehicle from the intervehicular distance and the speed of the vehicle and according to these values calculates the desired deceleration, which is stored in a memory 6. When the driver's decelerating operation is detected from a change in throttle valve opening, the shift ratio of a transmission 5 is controlled according to the desired deceleration to effect deceleration control. Since the number of siturations in requiring no braking operations increases, the amount of the driver's driving operation is decreased. The deceleration control is not automatically effected under a condition wherein the driver thinks that decelerating action is not necessary. Further, the driver has an incongruous feeling by making the value of the desired deceleration smaller as the acceleration of the vehicle is the greater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for a vehicle, and more particularly, to a traveling control device that, when a driver performs a deceleration operation, decelerates quickly to a speed suitable for a traveling condition. The present invention relates to a travel control device for a vehicle that performs the following.

[0002]

2. Description of the Related Art A conventional traveling control device for a vehicle determines whether or not the own vehicle needs to be decelerated based on the speed of the own vehicle, the inter-vehicle distance between the preceding vehicle and the own vehicle, and the relative speed. 2. Description of the Related Art There is known an automatic deceleration that reduces a driver's operation amount and improves vehicle safety. In these vehicle travel control devices, when the preceding vehicle suddenly decelerates, there is a time delay before a change in the following distance or the relative speed is detected, so that the timing of starting the deceleration may be delayed. there were.

In order to avoid the delay in the timing of the deceleration operation, for example, in a vehicle traveling control device described in Japanese Patent Application Laid-Open No. Hei 6-336125, in addition to the own vehicle speed, the inter-vehicle distance, and the relative speed, The relative acceleration is used as a material for determining whether or not the own vehicle needs to be decelerated. When the relative acceleration is large, a control is performed so that a series of deceleration operations are performed immediately. That is, when the preceding vehicle suddenly decelerates, a large value is detected as the relative acceleration, so that a rapid deceleration operation is performed and an appropriate inter-vehicle distance is maintained.

[0004]

However, the inter-vehicle distance that the driver feels that a deceleration operation is necessary differs depending on the surrounding conditions and the driving ability of the individual. Since the deceleration operation is automatically performed depending on the conditions, the vehicle is decelerated even in a situation where the driver thinks that the deceleration operation is not necessary, and there is a problem that the driver feels strange. Also, when the vehicle is traveling at a constant speed in the traffic flow and the preceding vehicle suddenly decelerates, the vehicle accelerates when the preceding vehicle is traveling at almost constant speed. Even when the vehicle approaches, a large value is detected as the relative acceleration. For this reason, even when the own vehicle accelerates and approaches the preceding vehicle, if the inter-vehicle distance, the relative speed, and the relative acceleration exceed the determination conditions for performing the deceleration operation, the vehicle is rapidly decelerated.

In a normal running state, the driver accelerates the own vehicle, reduces the inter-vehicle distance to a desired distance, and then gradually decelerates to the extent that the vehicle follows the preceding vehicle. There is also a problem that the sudden deceleration may give the driver a sense of incongruity. The present invention has been made in view of such conventional problems, and provides a vehicle travel control device that reduces the amount of driving operation of a driver, improves the safety of a vehicle, and has less discomfort to the driver. Aim.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a vehicle speed detecting section for detecting a vehicle speed, an inter-vehicle distance detecting section for detecting a distance between an own vehicle and an object existing in front of the own vehicle, Relative speed detecting means for detecting the relative speed between the car and the object, acceleration detecting means for detecting the acceleration of the own vehicle, decelerating operation detecting means for detecting the decelerating operation of the driver, own vehicle speed, distance, relative speed and When the driver's deceleration operation is detected by the target deceleration calculation means for calculating the target deceleration based on the own vehicle acceleration and the deceleration operation detection means, the own vehicle speed is reduced according to the target deceleration. It has a deceleration control means.

It is preferable that the target deceleration calculating means calculates a smaller target deceleration as the own vehicle acceleration increases, as long as the own vehicle speed, the distance, and the relative speed are the same. Further, it is preferable that the target deceleration calculating means always calculates the target deceleration based on the own vehicle speed, the distance, the relative speed and the own vehicle acceleration.

The deceleration operation detecting means can detect that the accelerator opening has changed from the open state to the closed state as the driver's deceleration operation. Further, the deceleration operation detecting means can also detect a depression operation of a brake pedal as the driver's deceleration operation. Further, it is preferable that the deceleration control means controls the engine brake to reduce the vehicle speed.

[0009]

In the vehicle travel control device according to the present invention, the target deceleration is calculated based on the own vehicle speed, the distance, the relative speed, and the own vehicle acceleration, for example, when the accelerator opening changes from the open state to the closed state. When the deceleration operation detecting means detects that the driver has performed the deceleration operation, the deceleration control is performed in accordance with the target deceleration, so that the accelerator is depressed with the intention of shortening the inter-vehicle distance. When the driver considers that the deceleration operation is unnecessary when the driver is in the vehicle, there is no inconvenience that the deceleration control is automatically performed. In addition, when the driver turns off the accelerator or the like, by performing appropriate deceleration control, it is possible to increase the number of cases where the brake operation is unnecessary.

If the vehicle speed, the distance, and the relative speed are the same, a smaller target deceleration is calculated as the vehicle acceleration increases, and deceleration control is performed in accordance with the target deceleration.
For example, when accelerating by depressing the accelerator,
Since the own vehicle acceleration has a large value, a small target deceleration is calculated. At this time, if the driver turns off the accelerator, gentle deceleration control is performed according to the small target deceleration. Therefore, after acceleration for the purpose of shortening the inter-vehicle distance, the inter-vehicle distance is sufficiently reduced, so that when the accelerator is turned off, gentle deceleration control is performed, and the driver does not feel uncomfortable.

On the other hand, when the vehicle is traveling at a substantially constant speed, the own vehicle acceleration is a small value. Therefore, even if the own vehicle speed, the distance, and the relative speed are the same as the above conditions, a large target deceleration cannot be obtained. It has been calculated. At this time, if the accelerator is turned off, according to the large target deceleration, for example,
Sudden deceleration control for increasing the gear ratio and increasing the engine brake amount is performed. Therefore, when the accelerator is turned off due to sudden deceleration of the preceding vehicle when the accelerator is lightly depressed and the vehicle is traveling at almost constant speed, rapid deceleration control is performed, and the approach to the preceding vehicle is performed. Is avoided.

In addition, by constantly calculating the target deceleration, when the deceleration operation detecting means detects the deceleration operation, the deceleration control according to the target deceleration can be immediately performed. Further, by detecting the depression operation of the brake pedal as the driver's deceleration operation, when the brake pedal is depressed, appropriate deceleration control is performed, so that the safety of the traveling vehicle can be improved. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to examples. FIG. 1 shows the configuration of the embodiment. The vehicle travel control device includes an arithmetic processing unit 1, an inter-vehicle distance detecting unit 2, a vehicle speed sensor 3 as a vehicle speed detecting unit, an accelerator opening sensor 4, and a transmission 5. The inter-vehicle distance detecting unit 2 is composed of a laser range finder, detects an inter-vehicle distance D with respect to a preceding vehicle or an object existing ahead, and outputs the same to the arithmetic processing unit 1. Further, as the inter-vehicle distance detecting unit, a unit that uses a laser radar or a relay relay or a unit that detects the inter-vehicle distance D based on the position of the preceding vehicle in an image obtained by capturing an image of the situation in front of the own vehicle can be used.

The vehicle speed sensor 3 detects the vehicle speed V and outputs it to the arithmetic processing unit 1. The accelerator opening sensor 4 detects the opening of the throttle valve controlled by the accelerator pedal, and outputs it to the arithmetic processing unit 1. The arithmetic processing unit 1 has a memory 6
And the relative speed R based on the following distance D and the own vehicle speed V
V and the host vehicle acceleration AC are calculated, and a target deceleration G is obtained based on these values and stored in the memory 6. Also,
Detects the driver's deceleration operation from the change in accelerator opening,
Transmission 5 which is a stepped automatic transmission based on target deceleration G
Control the transmission ratio. Note that the inter-vehicle distance D corresponds to the distance of the invention.

First, the flow of the operation in this embodiment will be briefly described. The arithmetic processing unit 1 reads the inter-vehicle distance D and the own vehicle speed V, and calculates the relative speed RV and the own vehicle acceleration AC. Note that the relative speed RV is positive when approaching the preceding vehicle. Next, based on these values, a target deceleration G is obtained by referring to a look-up table provided in advance and stored in the memory 6. The target deceleration G is updated every 0.1 seconds, and the memory 6 always stores the target deceleration G calculated from the latest data.

In parallel with the above processing, the arithmetic processing unit 1 constantly monitors the output from the accelerator opening sensor 4. If it is determined that the throttle valve connected to the accelerator pedal has changed from the open state to the closed state, that is, if it is detected that the driver has performed a deceleration operation, the memory 6
Transmission 5 so as to achieve the target deceleration G stored in
Is shifted down to control the amount of engine braking to perform deceleration control.

Next, the operation of the arithmetic processing unit 1 will be described in detail with reference to the flowcharts shown in FIGS. FIG. 2 shows the flow of the target deceleration G calculation operation. Step 10
In step 1, an inter-vehicle distance D is read from the inter-vehicle distance detector 2 at predetermined time intervals, and in step 102, the vehicle speed V is read from the vehicle speed sensor 3 at predetermined time intervals. Step 103
Then, the relative speed RV with respect to the preceding vehicle is calculated from the current inter-vehicle distance D and the inter-vehicle distance D ′ detected a predetermined time before. Also,
In step 104, the host vehicle acceleration AC is calculated from the current host vehicle speed V and the host vehicle speed V 'before a predetermined time.

In step 105, a case for switching the table used for calculating the target deceleration G is determined according to the value of the vehicle acceleration AC. That is, if the host vehicle acceleration AC is smaller than the predetermined value a1, the process proceeds to step 106.
If the vehicle acceleration AC is equal to or more than the value a1 and smaller than the value a2,
Proceed to step 107. If the value is equal to or more than the value a2, the process proceeds to step 108.

In the following steps 106, 107, 108 and 109, a target deceleration G is calculated. As an example, the vehicle speed V is V (1) and the relative speed RV is R
A method of calculating the target deceleration G when V (1) and the inter-vehicle distance D is D (1) will be described. When the own vehicle acceleration AC is smaller than the value a1, the process proceeds to step 106, where the index ID is obtained from the own vehicle speed V and the relative speed RV using a table TAB1 which is a lookup table shown in FIG.
Read X. Since the own vehicle speed V is V (1) and the relative speed RV is RV (1), the index IDX is IDX.
(A).

Next, at step 109, the target deceleration G is read from the index IDX and the inter-vehicle distance D using a table TAB4, which is a look-up table shown in FIG. The index IDX is IDX (a) and the following distance D
Is D (1), the target deceleration G is G (a). When the host vehicle acceleration AC is equal to or more than the value a1 and smaller than the value a2, the process proceeds to step 107, where TAB shown in FIG.
2, the same processing as in step 106 is performed, and IDX (b) is read as the index IDX.

Next, at step 109, the table TAB4
G (b) is read as the target deceleration G from. When the vehicle acceleration AC is equal to or more than the value a2, the process proceeds to step 108,
Index IDX from TAB3 shown in FIG.
(C) is read and the target deceleration G
Read (c). In step 110, step 10
The target deceleration G read at 9 is stored in the memory 6. The processing from step 101 to step 110 is repeated every 0.1 seconds, and the memory 6 stores the target deceleration G constantly obtained from the latest data.

By the above processing, even if the own vehicle speed V, the relative speed RV, and the following distance D are the same value, the own vehicle acceleration A
If the value of C is different, the value of the target deceleration G will be different. Look-up tables TAB1, TAB2, TAB
3 and TAB4 are configured such that the larger the vehicle acceleration AC, the smaller the target deceleration G becomes. When the table TAB1 is selected, that is, when the host vehicle acceleration AC is smaller than a1, the host vehicle speed V becomes V
(1) If the inter-vehicle distance D is D (1), the relative speed RV
The relationship between and the target deceleration G is represented by a curve of the inter-vehicle distance D (1) shown in FIG. If the relative speed RV is large, the possibility of a sudden approach becomes large, so that the target deceleration G
Has been created to be larger.

When the vehicle acceleration AC is equal to or greater than a1 and smaller than a2 and the table TAB2 is selected, the relationship between the relative speed RV and the target deceleration G is determined by the following formula (B) shown in FIG. The vehicle acceleration AC is represented by the curve a).
When the table TAB3 is selected at two or more, the relationship between the relative speed RV and the target deceleration G is represented by a curve of the inter-vehicle distance D (1) shown in FIG. Therefore,
If the own vehicle speed V is V (1), the inter-vehicle distance D is D (1), and the relative speed RV is RV (1), the target deceleration G (a) when the own vehicle acceleration AC is small> the own vehicle acceleration The target deceleration G (b) when the AC is medium is larger than the target deceleration G (c) when the own vehicle acceleration AC is large.

In each table, the inter-vehicle distance D (1)
The relationship between the relative speed RV and the target deceleration G for a shorter inter-vehicle distance D (2) is also shown. If the inter-vehicle distance D is small, the possibility of approaching becomes large, so the target deceleration G
Each table is created to be larger. Although not shown, the relationship between the own vehicle speed V and the target deceleration G is similar to the relative speed. A table has been created so that

In parallel with the above processing, the arithmetic processing section 1 monitors the output of the accelerator opening sensor 4 and detects the moment when the throttle opening changes from the open state to the closed state as the driver's deceleration operation. Detected. FIG. 3 shows the flow of the deceleration operation detecting operation. First, in step 201, the accelerator opening is read every predetermined time. In step 202, it is determined whether or not the detected accelerator opening is in the closed state. If the accelerator opening is in the closed state, the process proceeds to step 203. If it is not in the closed state, the process returns to step 201, and the monitoring of the accelerator opening is continued.

In step 203, it is determined whether or not the accelerator opening detected immediately before is open, and if not, the process returns to step 201. If it is in the open state, the process proceeds to step 204. In other words, if the immediately preceding accelerator state is open, and if the accelerator state at the time of detection is closed, the moment when the driver turns off the accelerator, that is, the moment when the deceleration operation is performed, is detected, The process proceeds to step 204 to perform the deceleration control.

In step 204, the transmission 5 is controlled so as to achieve the target deceleration G stored in the memory 6. The transmission 5 is a stepped transmission, and the relationship between the vehicle speed and the gear ratio and the engine braking amount has characteristics as shown in FIG. Therefore, the arithmetic processing unit 1 performs the deceleration control by downshifting to a speed where the engine brake amount closest to the target deceleration G can be obtained.

Steps 101 and 103 of the flowchart constitute a relative speed detecting means of the present invention, and steps 102 and 104 constitute an acceleration detecting means. Also, steps 105 to 109
The target deceleration calculating means of the present invention is constituted,
Step 203 constitutes deceleration operation detecting means, and step 204 constitutes deceleration control means.

According to such an operation, when it is detected from the detection result of the accelerator opening sensor 4 that the driver has performed a deceleration operation, the deceleration control is performed, so that the driver does not need the deceleration operation. In such a situation, there is no inconvenience that the deceleration control is automatically performed. Also,
When the driver turns off the accelerator, appropriate deceleration control is performed immediately, so that the number of cases where a brake operation is unnecessary can be increased, and the amount of driving operation of the driver can be reduced.

As the own vehicle acceleration increases, a smaller target deceleration is obtained from the look-up table. For example, in a state where the accelerator is depressed and accelerated for the purpose of shortening the inter-vehicle distance, a small target deceleration is obtained. Can be At this time, if the accelerator is turned off, gentle deceleration control according to the small target deceleration is performed, and the driver does not feel uncomfortable.

In a state where the accelerator pedal is lightly depressed and the vehicle is traveling at a substantially constant speed, a small value is detected as the own vehicle acceleration, and a large target deceleration is calculated. At this time, if the accelerator is turned off due to rapid deceleration of the preceding vehicle, the gear position is downshifted according to the large target deceleration, and the engine braking amount is increased.
Sudden deceleration control is performed, avoiding approach to the preceding vehicle, and ensuring the safety of the traveling vehicle.

In the present embodiment, the method of detecting the deceleration operation from the accelerator operation is used as the deceleration operation detection means. However, the present invention is not limited to this, and the driver has the intention to decelerate. The deceleration control may be performed if the driver does not need the deceleration operation further by using a method of detecting the depressing operation of the brake pedal. And the driver's discomfort is reduced.

In this embodiment, the vehicle acceleration A
The lookup table to be referred to on the first sheet is divided into three types according to the value of C. However, the present invention is not limited to this. The lookup table can be divided into an arbitrary number. become. Further, as a method of calculating the target deceleration G, a look-up table was used, but the present invention is not limited to this. The own vehicle acceleration AC, the own vehicle speed V,
What is necessary is just to be able to calculate the target deceleration G from the relative speed RV and the inter-vehicle distance D.

Also, the target deceleration G is constantly calculated, the value stored in the memory 6 is updated, and when the deceleration operation is detected, the target deceleration G stored in the memory 6 is detected. Although the deceleration control is performed using the speed G, the present invention is not limited to this. For example, when the deceleration operation detecting means detects that the driver has performed the deceleration operation, the target deceleration G is calculated. By performing the deceleration control, the same effect can be obtained while minimizing the arithmetic processing required for calculating the target deceleration.

Further, as a method of performing the deceleration control, a method of providing a stepped transmission and controlling the speed ratio is used. However, the present invention is not limited to this. By providing a stepped transmission and controlling the gear ratio, deceleration control can be performed with higher accuracy. Also, a brake actuator may be provided to control the amount of brake assist to perform deceleration control.

[0036]

As described above, the vehicle speed, the distance,
According to the relative speed and the own vehicle acceleration, an appropriate target deceleration is obtained, and when it is detected that the driver has performed the deceleration operation, the deceleration control according to the target deceleration is performed. In a situation where the driver does not need deceleration,
There is no inconvenience that the deceleration control is automatically performed, and the number of cases where the brake operation is unnecessary is increased. Therefore, the uncomfortable feeling given to the driver is reduced, and the driving operation amount of the driver is reduced.

Further, the value of the target deceleration is reduced as the own vehicle acceleration is increased. For example, when a deceleration operation is detected while the own vehicle is accelerating, a small target deceleration is calculated. As a result, gentle deceleration control is performed, and the uncomfortable feeling given to the driver is further reduced. On the other hand, when the own vehicle is traveling at a constant speed and the preceding vehicle suddenly decelerates, a large target deceleration is calculated.For example, a rapid deceleration control that increases the engine speed by increasing the gear ratio is performed. Therefore, approach to the preceding vehicle is avoided, and the safety of the traveling vehicle is ensured.

Further, by constantly calculating the target deceleration, when the deceleration operation detecting means detects the deceleration operation, the deceleration control according to the target deceleration can be immediately performed. Further, by detecting the depression operation of the brake pedal as the driver's deceleration operation, when the brake pedal is depressed, appropriate deceleration control is performed, so that the safety of the traveling vehicle can be improved. .

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a flow of a target deceleration G calculation operation in the embodiment.

FIG. 3 is a flowchart showing a flow of a deceleration operation detecting operation in the embodiment.

FIG. 4 is a view showing a lookup table for calculating a target deceleration G;

FIG. 5 is a view showing a lookup table for calculating a target deceleration G;

FIG. 6 is a diagram illustrating the relationship between the host vehicle acceleration and a target deceleration G.

FIG. 7 is a diagram showing a relationship between a transmission gear ratio and an engine braking amount.

[Explanation of symbols]

 Reference Signs List 1 arithmetic processing unit 2 inter-vehicle distance detecting unit 3 vehicle speed sensor 4 accelerator opening sensor 5 transmission 6 memory

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3D044 AA21 AA45 AC03 AC24 AC26 AC28 AC59 AD17 AE04 AE14 AE19 AE21 3D046 BB18 EE01 GG02 GG06 HH02 HH05 HH20 HH22 HH26 5H180 AA01 CC03 CC12 CC14 LL01 LL04 LL09

Claims (6)

[Claims] 1. A vehicle speed detecting section for detecting a speed of a host vehicle, an inter-vehicle distance detecting section for detecting a distance between the host vehicle and an object existing in front of the host vehicle, and detecting a relative speed between the host vehicle and the object. Relative speed detection means, acceleration detection means for detecting the vehicle acceleration, deceleration operation detection means for detecting the deceleration operation of the driver,
A target deceleration calculating means for calculating a target deceleration based on the host vehicle speed, the distance, the relative speed and the host vehicle acceleration; and the target deceleration when the deceleration operation of the driver is detected by the deceleration operation detecting means. A travel control device for a vehicle, comprising deceleration control means for reducing the speed of the vehicle according to the speed. 2. The method according to claim 1, wherein the target deceleration calculating means includes:
2. The travel control device for a vehicle according to claim 1, wherein if the value of the distance and the relative speed are the same, a smaller target deceleration is calculated as the own vehicle acceleration increases. 3. The target deceleration calculating means always calculates a target deceleration based on a host vehicle speed, a distance, a relative speed, and a host vehicle acceleration.
The traveling control device for a vehicle according to the above. 4. The apparatus according to claim 1, wherein said deceleration operation detecting means detects that the accelerator opening has changed from an open state to a closed state as a driver's deceleration operation.
The traveling control device for a vehicle according to the above. 5. The vehicle travel control device according to claim 1, wherein the deceleration operation detecting means detects a depression operation of a brake pedal as a driver's deceleration operation. 6. The vehicle travel control device according to claim 1, wherein the deceleration control means controls an engine brake to reduce the speed of the host vehicle.