JP2003054395A - Deceleration control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically keep a distance between two cars with respect to a leading car by detecting the driver's decelerating intention. SOLUTION: When a preceding car condition calculating means M1 calculates a distance between a self-car and the preceding car, and a relative peed on the basis of a result of the detection of an object in the advancing direction of the self-car by an object detecting device Sr, a deceleration necessity judging means M3 judges the presence or absence of the necessity of deceleration of the self-car on the basis of the distance between cars and the relative speed. When the deceleration necessity judging means M3 judges the necessity of deceleration, and a decelerating intention detecting means M2 detects the driver' s decelerating intention, an automatic decelerating means M4 operates decelerating means 31, 32 to automatically decelerate the self-car without changing the distance between cars with respect to the preceding car. Accordingly, the distance between cars with respect to the preceding car can be automatically kept without performing the special decelerating operation by a driver, and the operating load on the drive can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle deceleration control device for facilitating follow-up running to a preceding vehicle by detecting the driver's intention to decelerate and automatically decelerating.

[0002]

2. Description of the Related Art An adaptive cruise control system that performs constant-speed traveling control at a preset speed when no preceding vehicle exists, and performs constant-vehicle distance traveling control at a preset inter-vehicle distance when a preceding vehicle exists ( AC
C system) is known from, for example, Japanese Patent Laid-Open No. 8-118995.

[0003]

By the way, the brakes for decelerating the vehicle include: Engine braking by releasing the accelerator pedal. Shift down brakes due to shift down (including shifting to the LOW side of the continuously variable transmission). A service brake operated by operating a brake pedal is used alone or in combination. Besides these brakes, parking brakes, exhaust brakes,
There are regenerative brakes, but they are excluded here.

The deceleration of the vehicle obtained by the engine brake, the shift down brake and the service brake varies depending on the loading state of the vehicle and the gradient of the road, but in general, the engine brake has a maximum of 0.06 G and the shift down brake has a maximum of 0. The maximum is 15G and the service brake is about 0.80G.

If the deceleration required to maintain the vehicle-to-vehicle distance is less than 0.06 G, it is sufficient for the driver to release the accelerator pedal and activate the engine brake, but further reduction is required. When speed is required, the driver has to release the accelerator pedal and then perform the downshift operation and the brake pedal operation, which causes a problem of increased fatigue of the driver when the road is congested. If the engine braking effect is enhanced to generate sufficient deceleration, the distance between the preceding vehicle and the preceding vehicle can be adjusted simply by adjusting the extent to which the accelerator pedal is returned, without the need for downshift operation or brake pedal operation. It is possible to maintain the distance, but in this case, since a delicate accelerator operation is required, the driver's fatigue may rather increase.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to automatically maintain a vehicle-to-vehicle distance from a preceding vehicle by detecting a driver's intention to decelerate.

[0007]

The present invention achieves the above object by the structure shown in the claim correspondence diagram of FIG.

That is, according to the invention described in claim 1, an object detection device for detecting an object in the traveling direction of the vehicle,
Based on the detection result of the object detection device, the preceding vehicle state calculation means for calculating the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle followed by the own vehicle, the deceleration intention detection means for detecting the driver's deceleration intention, The deceleration means for decelerating the vehicle, the deceleration necessity judging means for judging whether or not the own vehicle needs to be decelerated based on the inter-vehicle distance and the relative speed calculated by the preceding vehicle state calculating means, and the deceleration necessity judging means for deceleration. When the deceleration intention detection means determines that there is a need for the driver and the deceleration intention detection means detects the driver's deceleration intention, the automatic deceleration means is provided to operate the deceleration means so that the inter-vehicle distance from the preceding vehicle does not change. A vehicle deceleration control device is proposed.

According to the above configuration, the preceding vehicle state calculation means calculates the inter-vehicle distance and the relative speed between the own vehicle and the preceding vehicle followed by the own vehicle based on the result of the object detection device detecting the object in the traveling direction of the own vehicle. Then, the deceleration necessity determining means determines whether or not it is necessary to decelerate the own vehicle based on the inter-vehicle distance and the relative speed with respect to the preceding vehicle. If the deceleration necessity determining means determines that there is a need for deceleration and the deceleration intention detecting means detects the driver's deceleration intention, the automatic deceleration means operates the deceleration means so that the inter-vehicle distance from the preceding vehicle does not change. Automatically decelerates the vehicle. Therefore, even if the driver does not perform a special deceleration operation, the inter-vehicle distance from the preceding vehicle can be automatically maintained, and the driver's operation load is reduced.

According to the invention described in claim 2,
In addition to the configuration of claim 1, there is proposed a vehicle deceleration control device characterized in that the deceleration intention detection means detects the driver's deceleration intention based on the released state of the accelerator pedal.

With the above arrangement, the deceleration intention detecting means detects the driver's deceleration intention based on the released state of the accelerator pedal, so that the deceleration intention can be detected easily and reliably.

According to the invention described in claim 3,
In addition to the configuration of claim 1 or claim 2, there is proposed a vehicle deceleration control device characterized in that the deceleration means is at least one of a transmission and a wheel brake.

According to the above construction, the deceleration means is composed of the transmission or the wheel brakes, so it is possible to generate deceleration sufficient to maintain the inter-vehicle distance from the preceding vehicle.

According to the invention described in claim 4,
In addition to the configuration according to any one of claims 1 to 3, the deceleration necessity determination means is required to maintain a predetermined inter-vehicle distance based on the inter-vehicle distance and the relative speed calculated by the preceding vehicle state calculation means. A deceleration control device for a vehicle is proposed, which is characterized by calculating a target deceleration of the host vehicle and determining whether or not deceleration is necessary based on the target deceleration.

According to the above construction, the deceleration necessity judging means judges whether or not the deceleration is necessary based on the required target deceleration calculated based on the inter-vehicle distance and the relative speed with respect to the preceding vehicle. When the target deceleration is small, it is possible to prevent the deceleration means from operating indiscriminately.

According to the invention described in claim 5,
In addition to the configuration according to any one of claims 1 to 4, when the operation of the speed reducing means by the operation of the driver is detected,
A deceleration control device for a vehicle is proposed, which is provided with an automatic deceleration stopping means for stopping the operation of the automatic deceleration means.

According to the above construction, when the driver voluntarily performs the deceleration operation, the automatic deceleration stopping means stops the operation of the automatic deceleration means, so that the deceleration operation of the driver is prioritized and the automatic deceleration interferes with the deceleration operation. Can be prevented.

The wheel brake 31 and the transmission 32 correspond to the speed reducing means of the present invention.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 to 9 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a vehicle equipped with an EBA system, FIG. 2 is a block diagram of an object detecting device, and FIG. 3 is an object detecting device. FIG. 4 is a perspective view, FIG. 4 is a flowchart illustrating the operation of the EBA system, FIG. 5 is a flowchart of the first embodiment of the engine brake assist module, FIG. 6 is a flowchart of the second embodiment of the engine brake assist module, and FIG. FIG. 8 is a flow chart of the third embodiment of the assist module, FIG. 8 is a time chart explaining the operation of the EBA system, and FIG. 9 is a claim correspondence diagram.

As shown in FIG. 1, a vehicle equipped with an engine brake assist system (EBA system) has wheel brakes 31 ... Which generate braking force by hydraulic pressure.
And a stepped (or stepless) transmission 32 that generates a braking force by downshifting, and these wheel brakes 31 ... And the transmission 32 constitute the deceleration means of the present invention. An EBA for controlling the operation of the wheel brakes 31 through the brake actuator 33, and downshifting the transmission 32 through the engine / mission ECU 34 (shifting to the LOW side in the continuously variable transmission) to decelerate the vehicle.
The system ECU 35 includes a signal from the object detection device Sr including a laser radar device and an accelerator pedal 36.
Signal from an accelerator pedal operation sensor Sa that detects the operation of the vehicle, a signal from a brake pedal operation sensor Sb that detects the operation of the brake pedal 37, a signal from a wheel speed sensor Sc that detects the wheel speed, and a yaw rate of the vehicle. The signal from the yaw rate sensor Sd that detects

As shown in FIGS. 2 and 3, an object detection device S for detecting the distance and direction of an object in front of the vehicle.
r is composed of a light sending unit 1, a light sending scanning unit 2, a light receiving unit 3, and a distance measurement processing unit 5. The light transmitting unit 1 includes a laser diode 11 that integrally includes a light transmitting lens, and a laser diode drive circuit 12 that drives the laser diode 11. The light transmission scanning unit 2 includes a light transmission mirror 13 that reflects the laser output from the laser diode 11.
And a motor 15 for reciprocally rotating the light-transmitting mirror 13 about the vertical axis 14, and a motor drive circuit 16 for controlling the drive of the motor 15. The light-transmitting beam emitted from the light-transmitting mirror 13 has a vertically long and narrow pattern with a limited horizontal width, which reciprocates in the left-right direction at a predetermined cycle to scan an object.

The light receiving section 3 includes a light receiving lens 17, a photodiode 18 for receiving a reflected wave converged by the light receiving lens 17 and converting it into an electric signal, and a light receiving amplifier circuit 19 for amplifying an output signal of the photodiode 18. Prepare

The distance measurement processing unit 5 communicates with the control circuit 24 for controlling the laser diode drive circuit 12 and the motor drive circuit 16 and the EBA system ECU 35 for controlling the engine brake assist system. 26, a counter circuit 27 for counting the time from the light emission of the laser to the light reception thereof, and a central processing unit 28 for calculating the distance to the object and the direction of the object.

Thus, the vertically elongated light-transmitting beam becomes an instantaneous detection area, and this detection area moves right and left in the entire detection area to scan the object. Then, the distance to the object is detected based on the time from when the light-transmitting beam is sent to when the reflected wave reflected by the object is received, and the instantaneous detection area The direction of the object is detected based on the direction.

As shown in FIG. 9, the EBA system ECU
Reference numeral 35 is a preceding vehicle state calculation means M1 and deceleration intention detection means M
2, deceleration necessity determination means M3, automatic deceleration means M4
And automatic deceleration stopping means M5. The preceding vehicle state calculation means M1 is based on the signal from the object detection device Sr.
The inter-vehicle distance to the preceding vehicle and the relative speed to the preceding vehicle are calculated. The deceleration intention detecting means M2 detects, based on a signal from the accelerator pedal operation sensor Sa, that the driver releases the accelerator pedal 36, that is, that the driver intends to decelerate the own vehicle. The deceleration necessity determination means M3 is configured to maintain the inter-vehicle distance with the preceding vehicle at the target inter-vehicle distance based on the inter-vehicle distance with the preceding vehicle and the relative speed with the preceding vehicle calculated by the preceding vehicle state calculation means M1. It is determined whether or not the vehicle needs to be decelerated, and the target deceleration required to maintain the inter-vehicle distance is calculated.

The automatic deceleration means M4 activates the deceleration means when the deceleration necessity judgment means M3 judges that it is necessary to decelerate the vehicle and the deceleration intention detection means M2 detects the driver's deceleration intention. Automatically slow down your vehicle. Specifically, this automatic deceleration is performed by the brake actuator 33.
Is operated by operating the wheel brakes 31 ... Or downshifting the transmission 32. Further, the automatic deceleration stopping means M5 decelerates the vehicle based on the signal from the brake pedal operation sensor Sb when the driver depresses the brake pedal 37, that is, the driver voluntarily operates the wheel brakes 31 ... When it is detected that the driver has the intention, the automatic deceleration by the automatic deceleration means M4 is prohibited or stopped to give priority to the driver's voluntary deceleration so as not to interfere with the automatic deceleration.

The above operation will be further described with reference to the flow charts of FIGS.

First, step S in the flowchart of FIG.
At 1, all the targets in the detection area are detected by the object detection device Sr and stored in the target memory. Based on the own vehicle speed calculated from the output of the wheel speed sensor Sc in the subsequent step S2 and the yaw rate calculated from the output of the yaw rate sensor Sd (or the steering angle calculated from the output of the steering angle sensor), the predicted own vehicle Calculates the traveling locus of. In the following step S3, the data in the previous target memory is compared with the current target data and the corresponding data is taken over. In step S4, the lock-on range is set within the width of 2 m on each of the left and right sides of the running locus of the vehicle. In step S5, a moving object closest to the own vehicle is set as a preceding vehicle candidate.

If there is a preceding vehicle in the following step S6,
In step S7, the required target deceleration of the own vehicle is calculated based on the relative speed to the preceding vehicle and the inter-vehicle distance. When the target deceleration is −0.06 G or less in step S8 and the accelerator pedal 36 is released by the accelerator pedal operation sensor Sa in step S9 to detect the driver's intention to decelerate, the engine brake assist module is detected in step S10. Is executed. If there is no preceding vehicle in step S6, the target deceleration is-
If it is not less than 0.06 G, that is, if the need for deceleration is extremely small, or if the accelerator pedal 36 is not released in step S9, that is, if the driver does not have the intention to decelerate, the engine brake assist module Is not executed.

Next, step S in the flowchart of FIG.
A first embodiment of the subroutine 10 (engine brake assist module) will be described with reference to the flowchart of FIG.

First, in step S21, the target deceleration is-
If it is 0.20 G or more, a downshift request is issued in accordance with the target deceleration in step S22 to the engine / mission EC.
It outputs to U34 and shifts down the transmission 32 to generate a braking force. As a result, step S23
If the target deceleration occurs at step S21, the process returns to step S21. In step S21, the target deceleration is -0.20G.
If not, that is, if the target deceleration exceeds the upper limit value, the target deceleration is limited to -0.20 G in step S24. After the target deceleration is limited to -0.20 G in step S24, or if the target deceleration does not occur in step S23, the brake pedal 3 is operated in step S25.
If 7 is not stepped on, the EBA system ECU 35 actuates the wheel brakes 31 ... Through the brake actuator 33 to generate the target deceleration in step S26. If the brake pedal 37 is depressed in step S25, the EBA system ECU is activated in step S27.
35 releases the operation of the wheel brakes 31 ... Through the brake actuator 33.

Next, step S in the flowchart of FIG.
A second embodiment of the subroutine 10 (engine brake assist module) will be described with reference to the flowchart of FIG. In this embodiment, the transmission 32 is a continuously variable type, and the brake actuator 33 is not controlled.

First, at step S31, the target deceleration is-
If it is 0.20 G or more, in step S32, the EBA system ECU 35 outputs a request to the engine / transmission ECU 34 to change the gear ratio of the continuously variable transmission 32 to the LOW side in accordance with the target deceleration, and the transmission 32 is set. Shift to generate braking force. If the target deceleration is not more than -0.20 G in step S31, that is, if the target deceleration exceeds the upper limit value, the target deceleration is limited to -0.20 G in step S33, and then in step S32. If the EBA system ECU 35 is -0.
A continuously variable transmission 3 via the engine / mission ECU 34 to generate a target deceleration of 20G.
Change the gear ratio of 2 to LOW.

Next, step S in the flow chart of FIG.
A third embodiment of the subroutine 10 (engine brake assist module) will be described with reference to the flowchart of FIG. In the present embodiment, the transmission 32 is not downshifted or shifted to the LOW side, but only deceleration is performed by the control of the brake actuator 33.

First, in step S41, the target deceleration is-
0.06G or less and the target deceleration is −0.20G or more in step S42, or step S42
If the target deceleration is not more than -0.20G, step S4
When the target deceleration is limited to -0.20 G in step 3 and the brake pedal 37 is not depressed in step S44,
In step S45, the EBA system ECU 35 actuates the wheel brakes 31 ... Through the brake actuator 33 to generate the target deceleration.

In the following step S46, the present target deceleration is calculated from the relative speed of the preceding vehicle and the inter-vehicle distance detected based on the signal from the object detecting device Sr, and then in step S4.
If the current target deceleration is 7 or less at the previous target deceleration +0.05 G and the current target deceleration is at least the previous target deceleration -0.05 G at step S48, that is, the previous value and the current value of the target deceleration If the deviation of is small, the previous target deceleration is maintained in step S49. On the other hand, in step S47, the current target deceleration is the previous target deceleration +0.0
If the current target deceleration is not 5 G or less or the current target deceleration is not more than the previous target deceleration −0.05 G in step S48, that is, if the deviation between the previous value and the current value of the target deceleration is large, this time in step S50. The target deceleration is set as a new target deceleration.

Further, in step S41, the target deceleration is-
If the target deceleration is not less than 0.06 G and the target deceleration is extremely small, or in step S44, the brake pedal 37
When is depressed and the driver spontaneously decelerates, the EBA system ECU 35 releases the drive of the brake actuator 33 and stops the operation of the wheel brakes 31 ... In step S51.

Next, an example of the effect of this embodiment will be described based on the time chart of FIG.

As a prerequisite, the preceding vehicle indicated by the broken line is
It runs at a constant speed of 80 km / h at 0.0 sec, and -0.15 at 0.1 sec to 3.6 sec.
2. Decelerate to 63.5 km / h from G to -0.06 G, and 3.
+0.05 G to +0. In 7 sec to 9.7 sec.
Accelerate to 80km / h at 10G, and run at a constant speed of 80km / h during 9.8sec.
It is assumed that the vehicle of the present invention or the conventional vehicle is following the preceding vehicle at an inter-vehicle distance of 40 m in 0.0 sec. (1) Movement of conventional vehicle . ~ 0.0sec; 80km / h, 40km
At m, follow the preceding vehicle. ． 0.1 sec to 0.7 sec; idle running time until the deceleration of the preceding vehicle is recognized and the accelerator pedal is released. ． 0.8sec-1.5sec: Engine brakes to decelerate by releasing the accelerator pedal. The time it takes to switch from the accelerator pedal to the brake pedal when recognizing that the engine brake cannot decelerate completely. ． 1.6sec-3.9sec; because the distance between cars has clogged before changing the brake pedal,
Depressing the brake pedal is stronger than the preceding vehicle-
Decelerate at 0.2G. ． 4.0 sec-4.7 sec; Release the brake pedal because the relative speed with the preceding vehicle has decreased and the inter-vehicle distance has clogged up. However, since the accelerator pedal has not been depressed yet, the engine brakes to decelerate at a deceleration of -0.06G. ． 4.8 sec to 11.5 sec; the inter-vehicle distance has begun to increase, so depress the accelerator pedal to reach 0.0 G to 0.
Accelerate with 13G acceleration. ． 11.6 sec-13.2 sec; in order to match the vehicle speed with the preceding vehicle, release the accelerator pedal and decelerate at a deceleration of -0.06 G by engine braking. ． 13.3sec ~; 80km / h, distance 4
It follows the preceding vehicle at 0m. (2) Characteristics of movement of conventional vehicle a. Since it takes time to decelerate with the required deceleration,
Greater deceleration is required. b. The vehicle speed becomes too low because the vehicle speed decreases further after the distance between the vehicles becomes shorter. c. Due to the b, the vehicle speed becomes too low, and the inter-vehicle distance becomes easy to open this time. d. Due to b, the acceleration at the time of acceleration for following the preceding vehicle becomes large. e. There is a gap in vehicle speed control when the accelerator pedal and brake pedal are changed. f. Due to the above a to e, the fluctuation range of the vehicle speed becomes large. g. Due to the above a to e, the fluctuation range of the inter-vehicle distance becomes large. h. The fuel consumption increases due to the above a to g. (3) Movement of the vehicle of the present invention . ~ 0.0sec; 80km / h, 40km
At m, follow the preceding vehicle. ． 0.1 sec to 0.7 sec; idle running time until the deceleration of the preceding vehicle is recognized and the accelerator pedal is released. ． 0.8sec-3.2sec; The engine brakes to decelerate by releasing the accelerator pedal. The target deceleration (-0.18G) is calculated from the inter-vehicle distance and the relative speed to the preceding vehicle when the accelerator pedal is released, and the engine is decelerated at a deceleration of -0.18G. When the engine brake cannot obtain the deceleration of -0.18 G, the automatic deceleration is performed by downshifting or wheel braking. ． 3.3 sec to 10.6 sec; the inter-vehicle distance started to increase, so depress the accelerator pedal to reach 0.0 G to 0.
Accelerate with 10G acceleration. ． 10.7sec ~; 80km / h, distance 4
It follows the preceding vehicle at 0m. (4) Characteristics of movement of the vehicle of the present invention a. Since deceleration is performed at the required deceleration in a short time, a small deceleration is sufficient. b. Since the vehicle speed change of the preceding vehicle can be followed well, the vehicle speed does not become too low. c. Due to b, the acceleration is small because the vehicle is not separated from the preceding vehicle. d. Since it is not necessary to step on the accelerator pedal and the brake pedal, the responsiveness of vehicle speed control is good. e. Due to the above a to d, the fluctuation range of the vehicle speed is small. f. Due to the above a to d, the fluctuation range of the inter-vehicle distance is small. g. Due to the above a to f, the fuel consumption amount is reduced.

Here, a specific method of calculating the target deceleration executed in step S7 of the flowchart of FIG. 4 will be described. (1) First Method In the first method, the target deceleration is set to be the deceleration required to make the relative speed to the preceding vehicle at the time of calculating the target deceleration zero after a predetermined time. That is, the target deceleration is defined by the following: target deceleration = relative speed of preceding vehicle / (basic time + head time * coefficient). In the above formula, the relative speed of the preceding vehicle is
(Current inter-vehicle distance-previous inter-vehicle distance) is divided by the processing cycle time, and the processing cycle time in the embodiment is 0.1 sec. The base time is the minimum time for the relative speed to converge to 0, and is set to 0.3 sec in the embodiment. The headway time is the time required for the vehicle to reach the position of the current preceding vehicle when the vehicle travels at the current vehicle speed, and is calculated by dividing the inter-vehicle distance by the vehicle speed. The coefficient determines the ratio of the basic time to the headway time, and is set to 0.12.

In the example described in the time chart of FIG.
At 0.7 seconds after the driver releases the accelerator pedal, the relative speed of the preceding vehicle is: relative speed of the preceding vehicle = (current vehicle distance-previous vehicle distance) / processing cycle time = (39.69-39.78) /0.1=-0.9 (m / sec), and the headway time is headway time = vehicle distance / vehicle speed = 39.69 / 22.22 = 1.79 (sec).

Therefore, the target deceleration is as follows: target deceleration = relative speed of preceding vehicle / (basic time + head time * coefficient) =-0.9 / (0.3 + 1.79 * 0.12) =-1. It becomes 75 (m / sec < ² >) =-0.18 (G). (2) Second Method In the second method, the target deceleration is a deceleration obtained by adding a predetermined deceleration to the deceleration of the preceding vehicle. That is, the target deceleration is defined by target deceleration = deceleration of the preceding vehicle + (basic deceleration + head time × coefficient). In the above equation, the deceleration of the preceding vehicle is obtained by dividing (absolute speed of the preceding vehicle of this time-absolute speed of the preceding vehicle of this time) by the processing cycle time (0.1 sec in the embodiment). Is the sum of the own vehicle speed and the relative speed of the preceding vehicle. The basic deceleration is 0.25 m / sec ² in the embodiment. The coefficient determines the ratio of the basic deceleration to the vehicle headway time.
It is said to be 05. The method of calculating the relative speed and headway time of the preceding vehicle is the same as that described in the first method.

In the example described in the time chart of FIG. 8,
At 0.7 seconds after the driver releases the accelerator pedal, the relative speed of the preceding vehicle this time is the relative speed of the preceding vehicle this time = (current vehicle distance-previous vehicle distance) / processing cycle time = (39.691-39. 780) /0.1 = -0.890 (m / sec), and the absolute speed of the preceding vehicle this time is the absolute speed of the preceding vehicle of this time = own vehicle speed + relative speed of the preceding vehicle = 22.222-0.890 = 21.332 (m / sec), and the relative speed of the preceding vehicle in the preceding cycle is the relative speed of the preceding vehicle in the previous cycle = (current vehicle distance-previous vehicle distance) / processing cycle time = (39.780-39.853) / 0.1 = −0.730 (m / sec), and the absolute speed of the preceding preceding vehicle is as follows: absolute speed of preceding preceding vehicle = vehicle speed + relative speed of preceding vehicle = 22.222−0.730 = 21. 492 (m / sec) Becomes

Therefore, the deceleration of the preceding vehicle is the deceleration of the preceding vehicle = (the absolute speed of the preceding vehicle this time-the absolute speed of the preceding preceding vehicle) / processing cycle time = (21.332-21.492) / 0. 1 = -1.60 (m / sec ² ) and the headway time is headway time = inter-vehicle distance / vehicle speed = 39.691 / 22.222 = 1.786 (sec).

Therefore, the target deceleration is the target deceleration = the deceleration of the preceding vehicle + (basic deceleration + head time * coefficient) =-1.60 + (-0.25 + 1.786 * 0.05) =-1 .76 (m / sec ² ) = -0.18 (G).

Although the embodiments of the present invention have been described in detail above, the present invention can be modified in various ways without departing from the scope of the invention.

For example, although the laser radar device is used as the object detection device Sr in the embodiment, a millimeter wave radar device or a television camera can be used.

Further, instead of the automatic deceleration stopping means M5 prohibiting or stopping the automatic deceleration when the driver depresses the brake pedal 37, the automatic deceleration is stopped when the driver shifts down the transmission 32 (or shifts to the LOW side). The means M5 may prohibit or stop the automatic deceleration.

[0050]

As described above, according to the invention as set forth in claim 1, the preceding vehicle state calculation means is based on the result of the object detection device detecting the object in the traveling direction of the own vehicle and the own vehicle and the own vehicle. After calculating the inter-vehicle distance and the relative speed with respect to the preceding vehicle, the deceleration necessity determination means determines whether or not there is a need to decelerate the own vehicle based on the inter-vehicle distance and the relative speed with the preceding vehicle. If the deceleration necessity determining means determines that there is a need for deceleration and the deceleration intention detecting means detects the driver's deceleration intention, the automatic deceleration means operates the deceleration means so that the inter-vehicle distance from the preceding vehicle does not change. Automatically decelerates the vehicle. Therefore, even if the driver does not perform a special deceleration operation, the inter-vehicle distance from the preceding vehicle can be automatically maintained, and the driver's operation load is reduced.

According to the invention described in claim 2,
Since the deceleration intention detecting means detects the driver's deceleration intention based on the release state of the accelerator pedal, the deceleration intention can be easily and surely detected.

According to the invention described in claim 3,
Since the deceleration means is composed of the transmission or the wheel brakes, it is possible to generate deceleration sufficient to maintain the inter-vehicle distance from the preceding vehicle.

According to the invention described in claim 4,
Since the deceleration necessity determining means determines whether or not deceleration is necessary based on the required target deceleration calculated based on the inter-vehicle distance and the relative speed with respect to the preceding vehicle, the deceleration means when the required target deceleration is small. Can be prevented from operating indiscriminately.

According to the invention described in claim 5,
When the driver voluntarily performs the deceleration operation, the automatic deceleration stopping means stops the operation of the automatic deceleration means, so that the deceleration operation of the driver is prioritized and the automatic deceleration can be prevented from interfering with the deceleration operation.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle equipped with an EBA system.

FIG. 2 is a block diagram of an object detection device.

FIG. 3 is a perspective view of an object detection device.

FIG. 4 is a flowchart illustrating the operation of the EBA system.

FIG. 5 is a flowchart of a first embodiment of the engine brake assist module.

FIG. 6 is a flowchart of a second embodiment of the engine brake assist module.

FIG. 7 is a flowchart of a third embodiment of the engine brake assist module.

FIG. 8 is a time chart explaining the operation of the EBA system.

FIG. 9: Claim correspondence diagram

[Explanation of symbols]

M1 preceding vehicle state calculation means M2 deceleration intention detection means M3 Deceleration necessity judgment means M4 automatic deceleration means M5 automatic deceleration stopping means Sr object detector 31 Wheel brakes (deceleration means) 32 Transmission (Reduction means) 36 accelerator pedal

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Claims (5)

[Claims] 1. An object detection device (Sr) for detecting an object in the traveling direction of the vehicle, and an inter-vehicle distance between the vehicle and a preceding vehicle followed by the vehicle based on a detection result of the object detection device (Sr). The preceding vehicle state calculating means (M1) for calculating the relative speed and the deceleration intention detecting means (M) for detecting the driver's deceleration intention.
2), deceleration means (31, 32) for decelerating the own vehicle, and deceleration for judging whether or not the own vehicle needs to be decelerated based on the inter-vehicle distance and the relative speed calculated by the preceding vehicle state calculating means (M1). When the necessity judgment means (M3) and the deceleration necessity judgment means (M3) judge that there is a need for deceleration, and the deceleration intention detection means (M2) detects the driver's deceleration intention, A deceleration control device for a vehicle, comprising: an automatic deceleration means (M4) for operating the deceleration means (31, 32) so that the inter-vehicle distance does not change. 2. The deceleration control device for a vehicle according to claim 1, wherein the deceleration intention detecting means (M2) detects the driver's deceleration intention based on the released state of the accelerator pedal (36). 3. The vehicle deceleration control device according to claim 1, wherein the deceleration means (31, 32) is at least one of a transmission and a wheel brake. 4. The deceleration necessity determining means (M3) is a target deceleration of the own vehicle required to maintain a predetermined inter-vehicle distance based on the inter-vehicle distance and the relative speed calculated by the preceding vehicle state calculating means (M1). The vehicle deceleration control device according to claim 1, wherein the deceleration control device determines whether or not deceleration is necessary based on the target deceleration. 5. A deceleration means (3) operated by a driver.
1, 32) is detected, automatic deceleration means (M
The deceleration control device for a vehicle according to any one of claims 1 to 4, further comprising an automatic deceleration stopping means (M5) for stopping the operation of 4).