JPH10129438A - Automatic braking control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the unnecessary braking control by noise, by installing a judging means for judging the reliability of the information on obstacle, detected this time, on the basis of the history of the memorized information on obstacle, and a controlling means for controlling the braking of a car on the basis of the result of the judgement. SOLUTION: A controlling device 10 outputs an instruction for warning braking (loose braking), to a brake actuator 34, when the controlling device judges the information on obstacle, and judges that the warning is necessary, on the basis of the input signals, and operates an alarm 36. Further the controlling device 10 memorizes the history of the information on obstacle, for judging the reliability of the information on obstacle. That is, the controlling device 10 acts as the memorizing means for memorizing the history of the information on obstacle, the judging means for judging the reliability of the information on obstacle, and the controlling means for controlling the braking through the brake actuator 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic braking control device for automatically braking according to a situation at the time of detecting an obstacle ahead of a vehicle.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a collision or a rear-end collision, an obstacle in front of an own vehicle is detected, and if the distance between the obstacle and the own vehicle is further increased, it is determined to be dangerous. A technique has been proposed in which, when approaching beyond a distance (threshold), the driver issues some warning or performs automatic braking.

For example, in Japanese Patent Application Laid-Open No. Hei 6-298022, a forward object (preceding vehicle) obtained by radar is disclosed.
A device that performs automatic braking based on the distance (inter-vehicle distance) from the vehicle, relative speed, and own vehicle speed is disclosed. More specifically, in this device, based on the own vehicle speed, the following distance and the relative speed,
A first threshold value at which a rear-end collision with a preceding vehicle can be prevented by braking;
A second threshold value that can prevent a collision with a preceding vehicle by a steering operation is calculated. Even if the detected inter-vehicle distance is smaller than the first threshold, the automatic braking is not performed when the detected distance is larger than the second threshold, and the automatic braking is performed only when the detected distance becomes equal to or less than the first and second thresholds. I try to let. Thereby, when the rear-end collision can be prevented only by the steering operation, when the driver is trying to prevent the rear-end collision by the steering operation, the automatic braking is prevented from being performed at a timing unexpected by the driver.

[0004]

However, in the conventional automatic braking control apparatus including the apparatus described in the above-mentioned publication, the distance is erroneously detected by radar noise, reflection by a minute object on the road surface, etc. If it is below the threshold,
Although there is no fear of collision, there is a problem that unnecessary automatic braking is performed and the maneuverability is deteriorated.

On the other hand, when a method of judging an object to be a collision only when an object which is considered to be an obstacle is continuously detected is adopted, the vehicle behavior of the own vehicle, for example, traveling such as a seam of an elevated road, etc. When the direction of the radar beam changes due to the occasional pitching of the vehicle, an object to be a collision target may be lost, and in this case, the original collision target may be regarded as not a collision target.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and has as its object to provide an automatic braking control device that can accurately determine an obstacle even if noise is applied to a radar. .

[0007]

As shown in FIG. 1, the present invention comprises an obstacle detecting means for detecting an obstacle ahead and a vehicle speed detecting means for detecting the speed of the own vehicle. And
In an automatic braking control device for braking the own vehicle based on the obstacle information detected by the obstacle detecting means and the own vehicle speed, a storage means for storing a history of the detected obstacle information; and This object is achieved by providing a determination unit that determines the reliability of the currently detected obstacle information based on the history of the obstacle information, and a control unit that controls braking of the own vehicle based on the determination result. It was done.

According to the present invention, the history of obstacle information is stored, and the reliability of the currently detected obstacle information is determined based on the history. Can be prevented.

For example, two types of braking, slow braking and full braking, are prepared, and if obstacle information that is to be subjected to full braking after slow braking is obtained, the obstacle approaches properly. You can judge that you are doing. Therefore, by not performing full braking unless there is a history that gentle braking has been performed immediately before full braking, automatic braking in consideration of reliability of obstacle information can be realized.

[0010]

In a preferred embodiment, the determination means creates a history of the obstacle information based on information on a relative speed and a distance from an obstacle obtained from the obstacle detection means. That is. As a result, the approaching state of the obstacle can be accurately estimated, and the accuracy of determining the reliability of the obstacle information can be improved.

Hereinafter, a more specific embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic configuration diagram of an automatic braking control device to which the present invention is applied.

In FIG. 2, a control unit (ECU) 10 detects an ON / OFF signal of a brake switch 14 for detecting that the driver has depressed a brake pedal 12, and detects that the accelerator pedal 15 has been depressed. From the accelerator sensor 16 for detecting the steering angle, a signal from the steering angle sensor 18 for detecting the steering angle of the steering wheel 17, and a radar (obstacle detecting means) 20 for detecting the distance to the obstacle.
, A signal from a wheel speed sensor (own vehicle speed detecting means) 22 to 28 for detecting the vehicle speed of the own vehicle, a signal from a yaw rate sensor 30 as information for obtaining a yaw rate, and the magnitude of an impact due to a collision. Acceleration (deceleration)
, A signal from the G sensor 32 and the G switch 33, and the like, which are detected by the control unit are input.

The control device 10 determines obstacle information based on these input signals and, when it determines that a warning is required, instructs the brake actuator 34 to perform warning braking (slow braking). And alarm 36
Is operated, and the brake lamp 38 is turned on to notify the following vehicle of the slow braking (since the slow braking is applied even when the driver does not depress the brake pedal 12). Further, if the vehicle still approaches the obstacle, the control device 10 issues a full braking instruction to the brake actuator 34 to avoid a collision.

The control device 10 stores the history of the obstacle information for determining the reliability of the obstacle information. That is, the control device 10 includes a storage unit that stores the history of the obstacle information,
The determination unit determines the reliability of the obstacle information, and plays a role of a control unit that controls braking through the brake actuator 34.

Next, the operation of the first embodiment of the present invention will be described with reference to the flowcharts of FIGS.

First, in step 100, the radar 2
A signal of 0 is input. The control device 10 processes this signal, and obtains the distance (relative distance) Lc to the obstacle. In step 102, the control device 10 obtains the own vehicle speed from the signals of the wheel speed sensors 22 to 28, and obtains the approach speed (relative speed) of the obstacle from the information on the relative distance Lc.
Calculate Vob. Further, an expected arrival time Tc is calculated from the information and the detected distance Lc.

In this embodiment, it is determined whether or not the obstacle is an oncoming vehicle, and the expected arrival time Tc is calculated in two ways as follows according to the result.

That is, as shown in FIG. 6, first, in step 102a, it is determined whether or not the relative speed Vob is equal to or lower than the own vehicle speed V. Here, when Vob ≦ V is satisfied, it is determined that the obstacle is either a fixed obstacle or another vehicle ahead traveling in the same direction as the own vehicle, and the process proceeds to step 102b to reach the expected arrival. The time Tc is calculated as in the following equation (1), with the relative distance being Lc.

Tc = Lc / Vob (1)

On the other hand, in step 102a, Vob ≦ V
Is not established, the relative speed Vob is higher than the own vehicle speed V.
Means that the obstacle is approaching the own vehicle. Therefore, it is determined that the obstacle is an oncoming vehicle, and the expected arrival time Tc is calculated by the following equation (2) in step 102c.

Tc = Lc / {(1 + α) × V−α × Vob} (2)

Here, α is an oncoming vehicle correction coefficient, and 0 <α <
It is one.

Next, in step 104, a steering angle signal from the steering angle sensor 18 is input, and a yaw rate signal is input from the yaw rate sensor 30. Then, the turning radius is calculated from the own vehicle speed and the yaw rate. Note that turning radius = (own vehicle speed / yaw rate).

Next, at step 106, the estimated arrival time Tc determines a full braking threshold W1 which is a threshold value for applying full braking when this value is interrupted. This full braking threshold W1 is determined by the graph of FIG. 7 using the reciprocal of the turning radius calculated above.

Next, at step 108, the estimated arrival time T
The warning braking threshold W2, which is a threshold value for performing the warning braking when c falls below this value, is determined. This is also determined by the graph of FIG. 8 using the turning radius and the reciprocal calculated above. The plurality of graphs in FIG. 8 indicate that the timing of performing the warning braking can be corrected earlier or later depending on the driver's preference or the like. Which graph to use is selected in advance by the driver using a dial or the like. or,
Although the graphs of the thresholds W1 and W2 in FIGS. 7 and 8 are represented by curves, they may be represented by broken lines.

Next, at step 110, the acceleration G of the vehicle is calculated based on the signals from the G sensor 32 and the G switch 33.

In the next step 112, it is determined whether or not the vehicle speed V is lower than the vehicle speed detection lower limit value Vo. The vehicle speed detection lower limit value Vo is, for example, about 5 km / h, and almost indicates a stopped state. The vehicle speed V is the vehicle speed detection lower limit value Vo
If not, the process proceeds to the next step 114, where the acceleration G calculated in step 110 exceeds an impact threshold value Gc corresponding to the magnitude of the impact when the vehicle actually collides, and Full braking flag F
It is determined whether or not f is the validity period Tff. The full braking flag Ff is a flag indicating that it is necessary to continue full braking as it is when full braking is being performed. If these conditions do not hold, the process proceeds to the next step 116.

In the next step 116, it is determined whether or not it is within a full braking duration Tf in which full braking is continued. If not within the full braking duration Tf, the next step 11
Proceed to 8. In step 118, it is determined whether or not the estimated arrival time Tc falls below the full braking threshold W1 and is within the validity period Tkf of the warning braking flag Fw. The warning braking flag Fw is a flag indicating that it is necessary to continue the warning braking as it is when the warning braking is being performed. If these conditions are not satisfied, the process proceeds to the next step 120.

In step 120, the brake switch 1
4 is ON (that is, whether the driver depresses the brake pedal 12 and performs the avoidance operation) or whether the steering speed dθ, which is the speed at which the steering wheel 16 is operated, exceeds the steering speed threshold (threshold) dθ0 ( It is determined whether or not the steering wheel is abrupt, that is, whether or not steering is avoided. As a result, when these conditions are not satisfied, the routine proceeds to the next step 122, where it is determined whether or not the warning braking duration Tk is maintained.

If not within the warning braking duration Tk,
In the next step 124, it is determined whether or not the flag FLG is ON. The flag FLG is a flag provided separately from the warning braking flag Fw, and is a flag for once releasing the warning braking when the warning braking duration Tk has elapsed within the warning braking flag valid period Tkf.

If the flag FLG is off, in the next step 126, whether or not warning braking is required, that is, the driver performs the avoidance operation despite the presence of an obstacle in the range where warning braking is required. It is determined whether or not it has been performed. As indicated by reference numeral B in FIG. 9, the expected arrival time Tc interrupts the warning braking threshold W2, and is smaller than the warning braking threshold W2, and the brake switch 14 is turned off (that is, the driver does not depress the brake pedal 12 and brakes. If the avoidance operation is not performed by the driver) and the steering speed dθ of the steering 16 is smaller than the steering speed threshold dθ0 (that is, the driver does not perform the avoidance by the steering operation), it is determined that the warning braking is necessary. Proceed to 128. In step 128, Tk,
A warning braking duration and a warning braking flag valid period indicated by Tkf are calculated. Then, in step 130, warning braking is started, the alarm 36 and the brake lamp 38 are operated, and the warning braking flag Fw and the flag FLG are turned on.

If it is determined in step 126 that the warning braking is not necessary, in step 132, the automatic braking is released and the operation of the alarm 36 and the brake lamp 38 is released. If the braking control is not originally performed, nothing is actually performed here.

That is, as shown in FIG. 9, when the obstacle is approaching without any danger avoidance operation, as shown in FIG. 9A, as long as the estimated arrival time Tc is longer than the warning braking threshold W2, the obstacle is not moved. Braking control is not performed as in the case where no detection is made.

If the driver performs the avoidance operation as a result of the warning braking, the warning braking is released. In step 120, it is determined whether or not the driver has performed the avoidance operation based on whether the brake switch 14 is turned on or the steering speed dθ of the steering 16 is equal to or greater than the steering speed threshold dθ0. When it is determined that the driver is performing the avoidance operation, in step 134,
The warning braking duration Tk and the warning braking flag Fw are reset. Then, the warning braking is released and the alarm 36
And the operation of the brake lamp 38 is released, and the flag FLG
Is turned off.

If the driver does not perform the avoidance operation despite performing the warning braking, it is determined in step 122 whether or not the warning braking duration Tk is within the warning braking duration Tk.
If it is within the warning braking duration Tk, the warning braking is continued as it is.

As shown by To in FIG. 10, even within the warning braking flag valid period Tkf, the warning braking duration Tk
Has elapsed, if it is determined in step 124 that the warning braking has been performed by turning on the flag FLG, the routine proceeds to step 134, where the warning braking is temporarily released.

Thereafter, when the obstacle is further approached and full braking is required, full braking is started. In step 118, as shown in FIG. 9, the estimated arrival time Tc interrupts the full braking threshold W1 (reference C), is smaller than the full braking threshold W1, and the warning braking flag valid period Tkf is determined at step 118. It is determined by whether or not it is within. If it is determined that full braking is necessary, in step 136, the full braking duration Tf and the full braking flag valid period Tff in FIG. 11 are calculated, and in the next step 138, full braking is started, and the alarm 36 and the brake are activated. The lamp 38 is operated, and the full braking flag Ff is turned on. If it is determined in step 116 that the braking time is within the full braking duration Tf, the full braking is continued.

Step 1 despite full braking continued
At 14, the acceleration G is equal to the shock threshold Gc.
If it is determined that it is larger and within the full braking flag valid period Tff, it is determined that a collision has occurred, and step 14 is performed.
At 0, the full braking duration Tf and the full braking flag valid period Tff are extended to infinity, and full braking is continued at step 142 to prevent damage and harm caused by the secondary collision, and the alarm 36 and the brake lamp 38 are activated. To continue.

On the other hand, if it is determined in step 112 that the vehicle speed V has decreased due to full braking and has become smaller than the vehicle speed detection lower limit Vo, it is determined that the vehicle is substantially in a stopped state, and the routine proceeds to step 144. It is determined whether or not the accelerator pedal 15 is depressed based on a signal from the accelerator sensor 16. When the accelerator pedal 15 is not depressed, the state is maintained as it is. When the accelerator pedal 15 is depressed, it is determined that the driver has started the next operation, and in the next step 146, the full braking is released, and the operation of the alarm 36 and the brake lamp 38 is released. The braking flag Ff is turned off. The automatic braking control is completed as described above, and the operation is then left to the driver's operation.

As described above, in the first embodiment, the full braking is not performed unless there is a history that the vehicle has entered the warning braking area immediately before. Therefore, even if an obstacle is suddenly detected by the radar 20 in the full braking region, unnecessary braking is prevented as noise.

In the present embodiment, in the warning braking region, gentle braking for warning, alarm issuance, and turning on of the brake lamp are actually performed. However, the gentle braking for warning is performed by the driver. It may be possible to select so as not to use the OFF switch. Further, the concept of the warning braking region may be used only to delete the execution itself on the system and to obtain a history that the vehicle has entered the warning braking region immediately before full braking.

Next, the operation of the second embodiment of the present invention will be described.

In the first embodiment, the radar 20
Even when continuous noise is input before and after the full braking threshold W2, the warning braking area is determined to be the full braking area, and the full braking control may be performed. Thus, the influence of the noise may not be completely removed. was there. Therefore, in the second embodiment, several steps are performed before and after the warning braking flag Fw and the full braking flag Ff valid period Tkf and Tff are calculated so as to determine whether or not the input signal is noise. Is added. Hereinafter, only differences from the first embodiment will be described.

FIGS. 12 and 13 are flowcharts corresponding to FIGS. 3 and 5, respectively, of the first embodiment.

In FIG. 12, between steps 100 and 102, two steps 202 and 204 (stocking the data of the two times of expected arrival time Tc) are added. That is, in step 202, the previous estimated arrival time Tc (i-1) is replaced with the previous estimated arrival time Tc (i-2)
In step 204, the current estimated arrival time Tc (i) is changed to the previous estimated arrival time Tc (i-1).
In the data area.

In FIG. 13, after it is determined in step 122 that the warning braking duration Tk is within the warning braking duration Tk, three steps 2
06, 208 and 210 are added to determine whether the input signal is noise.

First, at step 206, it is determined whether or not this step has been passed for the first time. For this determination, a counter that counts the number of times this step has passed may be provided.
If it is not the first pass, the warning braking is continued as it is.

In the case of the first pass, the next step 208
By evaluating the continuity of the current expected arrival time Tc (i), the previous expected arrival time Tc (i-1), and the previous expected arrival time Tc (i-2), the input signal becomes noise Is determined. The evaluation of the continuity of the three data is based on the current expected arrival time Tc (i) and the previous expected arrival time Tc (i−
This is performed by determining whether or not the absolute value of the difference between the average of 2) and the previous estimated arrival time Tc (i) is smaller than a certain threshold value W3. That is, the determination is made based on whether the following equation (3) is satisfied.

| {Tc (i) + Tc (i-2)} / 2−Tc (i-1) | <W3 (3)

As a result, when it is determined that there is continuity, it is determined that the object is not a noise but an obstacle, and the warning braking is continued. If there is no continuity, it is determined that noise is present, and in the next step 210, the warning braking duration T
k and the warning brake flag valid period Tkf are reset, the warning brake is released, the warning brake flag Fw and the flag FLG are turned off, and the operation of the alarm 36 and the brake lamp 38 is released.

In the second embodiment, by adding such a step, it is possible to accurately determine whether or not the input signal is noise even immediately before the full braking threshold W1.

The same determination can be made before and after the full braking flag Ff is set. In this case, the three steps 206, 208, and 210 are performed at step 116 in FIG. It may be added after it is determined to be inside.

In this case, the present invention can be applied not only to the history of the warning braking area to the full braking area but also to a system having no warning braking in some cases.

In the above embodiment, the continuity determination is performed using three data. However, the continuity determination is not limited to this. For example, four or more data points may be used. Good.

[0056]

As described above, according to the present invention,
By judging the reliability of the obstacle judgment based on the obstacle detection history, it is easy to determine whether or not the input signal is noise, and unnecessary braking control can be prevented, and driving performance can be prevented. Can be improved.

When the approaching state of the obstacle is estimated from the relative speed and distance information, the accuracy of the reliability of the obstacle determination can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a schematic configuration diagram of an automatic braking control device to which the present invention is applied.

FIG. 3 is a flowchart illustrating control according to the first embodiment;

FIG. 4 is a flowchart showing control of the first embodiment.

FIG. 5 is a flowchart showing control according to the first embodiment.

FIG. 6 is a flowchart showing control of the first embodiment.

FIG. 7 is a diagram showing a full braking fresh hold.

FIG. 8 is a diagram showing a warning braking threshold.

FIG. 9 is a diagram showing a state in which an obstacle approaches the vehicle properly.

FIG. 10 is a diagram showing a warning braking duration and a warning braking flag valid period.

FIG. 11 is a diagram showing a full braking duration and a full braking flag valid period.

FIG. 12 is a flowchart illustrating control according to the second embodiment.

FIG. 13 is a flowchart showing control according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Control device (ECU) 12 ... Brake pedal 14 ... Brake switch 16 ... Steering 18 ... Steering angle sensor 20 ... Radar (obstacle detection means) 22,24,26,28 ... Wheel speed sensor 30 ... Yaw rate 32 ... G sensor 33: G switch 34: Brake actuator 36: Alarm 38: Brake lamp

Claims (2)

[Claims] An obstacle detecting means for detecting an obstacle ahead of the vehicle, and a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, wherein the obstacle information detected by the obstacle detecting means and the own vehicle speed are detected. An automatic braking control device that brakes the own vehicle based on the history of the detected obstacle information; and a storage unit that stores the history of the detected obstacle information based on the stored history of the obstacle information. An automatic braking control device, comprising: determining means for determining reliability; and control means for controlling braking of the own vehicle based on the determination result. 2. The system according to claim 1, wherein the determination unit creates a history of the obstacle information based on information on a relative speed and a distance from the obstacle obtained from the obstacle detection unit. Braking control device.