JP3246204B2 - Automatic vehicle braking system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic braking device for a vehicle,
In particular, it relates to a device for assisting a braking force in an emergency.

[0002]

2. Description of the Related Art Generally, a vehicle travels in response to a driver's operation, and desired acceleration / deceleration and steering control are performed in accordance with a driver's operation of an accelerator, a brake, a steering, and the like. I have. Therefore, the driving operation is left to the driver's free will. Here, when the driver feels a danger of a collision, the driver steps on the brake to decelerate the vehicle, but in such an emergency, the maximum braking force is required,
Even in a very dangerous state, the pedaling force is often insufficient.

Therefore, in order to obtain a greater braking force of the vehicle, an automatic braking device has been proposed which assists the driver's operation to assist the braking force of the vehicle.

For example, Japanese Unexamined Patent Publication No. 60-38238 discloses that a necessary braking force is calculated on the basis of a distance between a host vehicle and a preceding vehicle, a relative speed, and the like. Have been shown to compensate for this. According to this configuration, the braking force can be assisted when necessary, and safety in an emergency can be improved.

[0005]

However, according to the above-described automatic braking device, unnecessary braking may be performed when a ball crosses ahead or when a guardrail is detected during a turn. In the above conventional example, when the driver completely releases his / her foot from the brake or when the depression force on the brake pedal is clearly reduced, the braking by the automatic braking device is not performed, but this alone is unnecessary. There is a problem that braking cannot be sufficiently reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has an object to provide an automatic braking system for a vehicle which can accurately recognize a case where braking assistance is required and can provide effective braking assistance. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION The present invention provides a physical danger determining means for determining a danger of a collision from a distance or a relative speed to an obstacle, and an emergency from a driver's operation state of a brake, a steering wheel or the like. Operation emergency judgment means for judging the degree, and automatic braking means for automatically braking when a predetermined signal is received, the physical danger judgment means that there is a risk of collision with an obstacle it is determined, and if it is determined that there is urgency to the operation of the driver's operation urgency judging means only, the automatic braking means is operated, the control means Ru activates the full braking
In addition, the conditions for judgment by the urgency judgment means
As a condition for judgment by the urgency judgment means,
Of the depressing force of the key and the depressing speed of the brake
At least one of them is included .

[0008] Further, the present invention relates to the distance and relative speed to an obstacle.
Physical risk judgment means for judging the risk of collision from the degree etc.
Emergency from the driver's brake, steering wheel, etc.
Operation urgency judging means for judging the degree and receiving a predetermined signal
Automatic braking means for automatically braking when
If there is a risk of collision with obstacles by means of
Is judged and the driver's operation is
Automatic braking is activated only when it is determined that there is acute
Control means to activate the full brake
Access condition as a condition for judgment in the urgency judgment means.
It is characterized in that it includes a time for changing from a vehicle to a brake .

Also, the present invention provides a method for controlling the distance and relative speed to an obstacle.
Physical risk judgment means for judging the risk of collision from the degree etc.
Emergency from the driver's brake, steering wheel, etc.
Operation urgency judging means for judging the degree and receiving a predetermined signal
Automatic braking means for automatically braking when
If there is a risk of collision with obstacles by means of
It is determined that the driver's operation is urgent
The automatic braking means is activated only when
The system further includes control means for operating, and the
It is characterized in that the condition for the determination includes the steering operation speed .

The control means determines that there is an urgency.
Feature that changes the standard based on the risk at that time
And

[0011] Also, the judgment by the physical risk judgment means
Condition that obstacle detection time is included
Features.

[0012]

[0013]

As described above, according to the automatic braking system for a vehicle according to the present invention, the degree of urgency is determined from the operating state of the driver such as the brake and the steering. When it is determined that the degree of urgency is high, the assisting of the braking by the automatic braking means is performed.
When the driver's operation is urgent, the probability of the need for brake assistance is very high, and this enables highly accurate control of the automatic braking device. And physical danger
Safety measures, both physical danger and operational urgency
Brake by automatic braking means when it is judged to be steep or urgent
By operating the braking, more accurate braking control
can do.

Further, a criterion for judging urgency is set.
By changing according to the risk at the time of
I can do it.

[0015] Further, by including the detection time of the obstacle as a judgment condition in the judgment means of the physical risk,
It is possible to prevent the automatic brake from malfunctioning due to the passage of a ball or the like having a short detection time.

By including at least one of the brake depressing strength and the brake depressing speed as a condition for judging the degree of urgency of operation, sudden braking in an emergency can be effectively detected and automatic braking can be performed. .

Further, by including the time for changing over from the accelerator to the brake as a condition for judging the degree of urgency of operation, it is possible to detect that the driver has changed quickly in an emergency and to operate the automatic braking effectively. it can.

Furthermore, by including the steering operation speed as a condition for judging the degree of operation urgency, it is possible to detect that the driver has attempted to avoid an obstacle and to perform effective braking control.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a main part of an embodiment. As input means, a vehicle speed sensor 1, an acceleration sensor 2,
It has a distance measuring sensor 3, a Doppler sensor 4, an accelerator pedal switch 5, a brake pedal switch 6, a brake pedal force sensor 7, a brake stroke sensor 8, and a steering angle sensor 9. Also, detection signals from these sensors and switches (hereinafter, referred to as sensors, etc.)
And is processed. As an output means, there are an alarm device 11, an automatic throttle device 12, and an automatic brake device 13, which are operated by a signal from the arithmetic unit 10.

Here, the vehicle speed sensor 1 detects, for example, the gear rotation speed of the transmission by an appropriate method, and detects the own vehicle speed. The acceleration sensor 2 generates an electric signal proportional to the input acceleration, and detects, for example, an acceleration acting on a weight as a pressing force on the piezoelectric element. The acceleration may be detected by differentiating the vehicle speed obtained by the vehicle speed sensor 1, and can be obtained from the difference between the vehicle speeds detected in each control cycle. The distance measuring sensor 3 irradiates, for example, a pulse of near-infrared rays to the front, and detects the inter-vehicle distance from the preceding vehicle from the time until the reflected light is received. The Doppler sensor 4 transmits, for example, a microwave or the like forward, detects a Doppler shift in a reflected wave, and detects a relative speed with respect to a preceding vehicle.
Further, this relative speed may be detected based on a change (differential) of the inter-vehicle distance. The accelerator pedal switch 5 and the brake pedal switch 6 are switch signals indicating that the driver has operated the accelerator pedal or the brake pedal. The brake depression force sensor 7 measures the depression force of the driver by the driver, and the brake stroke sensor 8 measures the brake depression amount. Further, the steering angle sensor 9 outputs a steering operation as a signal corresponding to the angle.

When the arithmetic unit 10 determines that the assistance of the brake is necessary in accordance with these various input signals, the alarm unit 11 generates, for example, an alarm sound. Further, the throttle is forcibly fully closed by the automatic throttle device 12 to decelerate the vehicle, and the automatic brake device 13 forcibly brakes the vehicle.

[Explanation of Overall Operation] Here, an overall flowchart in the present apparatus will be described with reference to FIG. First, the arithmetic unit 10 inputs signals from the sensors 1 to 9 (S1). Then, based on the obtained detection values, the collision risk and the operation urgency are calculated and calculated (S2,
S3). Next, it is determined whether the collision risk is equal to or higher than a predetermined value (S4). If the collision risk is equal to or higher than the predetermined value, it is determined whether the operation urgency is equal to or higher than the predetermined value (S5). If the degree of operation urgency is also equal to or higher than a predetermined value, it is considered that assistance for deceleration for the driver is necessary, and braking assistance using automatic braking is performed. Therefore, first, an alarm is output to notify the driver that the automatic brake is operating (S6). This provides an indication or audio output about the activation of the automatic brake, together with a predetermined alarm. Next, a calculation is made as to how much deceleration is required (S7), and an automatic brake is operated so as to obtain the calculated deceleration (S8).

When the degree of collision danger is less than a predetermined value in S4, when the operation urgency is less than a predetermined value in S5, and when the automatic brake is activated in S8, the automatic brake is activated next. It is determined whether or not (S9). If the driver is operating, it is determined whether or not the driver's brake pedaling force or brake depression stroke has decreased (S10). Since the reduction in the amount of brake operation by the driver means that the danger of collision has been avoided, the automatic brake is released (S11). On the other hand, if the automatic brake is not operating in S9 or if the brake operation amount has not been reduced in S10, the automatic brake is not required to be released and the process is terminated without passing through S11. The processing of S1 to S11 is repeated at a predetermined cycle. As described above, in this embodiment, the operation of the automatic brake is controlled in consideration of both the collision risk and the operation urgency. Therefore, it is possible to prevent the error movement of the automatic brake and to assist the effective braking.

[Calculation of Collision Risk] Next, the calculation of the collision risk in S2 will be described. The collision risk is calculated based on the limit of the driver's operation ability and the limit of the vehicle motion.

That is, the delay time td from when the driver starts operating the brake until the brake actually starts being applied, the average deceleration a0 due to the driver depressing the brake.
The distance that can be stopped by the brake is calculated based on. In this case, stopping distance XB by the operation of the brake, the xB = v0 · td + (1/2 ) · v0 2 / a0.

Here, v0 is the vehicle speed. This is illustrated in FIG. 3, where the vehicle travels (idle running) at the vehicle speed v0 for td after the brake pedal is depressed, and then decelerates at an average deceleration a0. , The vehicle speed becomes zero. Accordingly, the hatched area in FIG. 3 is the stoppable distance xB.

In consideration of the driver's operability and the vehicle's motion limit, td = 0.2 seconds and a0 =
A value of about 0.8 g is employed.

[0028] Collision can also be avoided by operating the steering wheel. In this case, the maximum lateral acceleration b0m
The avoidable distance by the steering is calculated based on ax and the steering operation speed T. The avoidable distance xS by steering is: W / 2 = (T / π) b0max ｛(xS / v0) − (T /
π) sin (π / T) （(xS / vS / v0)｝. Where W
Is the vehicle width. This is shown in FIG. 4 as shown in FIG. That is, assuming that there is an obstacle at the point of the distance xS, the condition is that the vehicle can pass through the position of xS at a steering angle of 0 °.

That is, the driver operates the steering wheel to avoid an obstacle, and gradually increases the steering angle. Then, the steering angle is returned, and the vehicle passes the side of the obstacle at a steering angle of 0 °. Next, the steering is operated to the opposite side, the traveling direction of the vehicle is returned to the original direction, and the vehicle moves in parallel. Here, if the collision is avoided in a state where the steering wheel is turned only in one direction at the maximum, the vehicle is directed in a direction perpendicular to the road, and there is a high risk of another collision. Therefore, the distance that can be avoided is set as a distance that can pass through the side of the obstacle at a steering angle of 0 °. In addition,
b0max is 0.4 g (where g represents gravitational acceleration)
The steering operation speed T is set to about one second.

The collision risk is determined to be dangerous when the distance from the obstacle is Δx, for example, when the following conditions are satisfied.

(I) Δx <xB (ii) Δx <xS (iii) Δx <xB and Δx <xS (iv) Δx <xB or Δx <xS These four conditions (i) to (iv) are as follows. Thought,
Either one is appropriately adopted.

[Calculation of Operation Urgency] Although it is conceivable to operate the automatic brake based on the above-mentioned judgment of the collision risk, in such a judgment of only the collision risk,
Malfunction may occur. For example, when a roadside object is detected at an entrance from a straight road to a curve, or when paper or the like flies, it is determined that the risk of collision is dangerous.If the driver operates the brake at this time, Means that the automatic brake is activated.

Therefore, in the present embodiment, it is determined whether or not the brake operation by the driver is urgent, not the condition that the driver is performing the brake operation. Therefore, calculation of the operation urgency in the brake operation will be described.

(Determination Based on Accelerator-to-Brake Depressing Time) The depressing time ΔT from when the accelerator pedal is released to when the brake pedal is depressed is measured. I do.

(Judgment method based on brake depression strength)
The pedaling force BF during the brake operation is measured, and when this BF is larger than a predetermined threshold value BFth, it is determined that the urgency is high. Alternatively, instead of the pedaling force BF, the brake stroke amount BS may be detected, and when this BS is larger than a predetermined threshold value BSTH, the degree of urgency may be determined to be large. Further, instead of these BF and BS, the deceleration gx of the own vehicle may be detected, and when this gx is larger than a predetermined threshold value gxth, it may be determined that the urgency is high. Further, instead of BF, BS, Gx, a brake oil pressure (master cylinder or wheel cylinder) BP may be detected, and when BP is larger than threshold value BPth, it may be determined that the degree of urgency is high.

(Judgment method based on brake depressing speed)
The change speed of the pedaling force BF during the brake operation, that is, the stepping speed d / dt (BF) is detected, and this d / dt is detected.
When (BF) is larger than a predetermined threshold value BFth, it is determined that the urgency is high. Note that d / dt (BS) may be used instead of d / dt (BF). In this case, the threshold is BSth. Further, d / dt (gX) may be used instead of d / dt (BF). The threshold in this case is gXth. Also, d / dt (BF),
d / dt (BS), d / dt instead of d / dt (Gx)
Using t (BP), d / dt (BP) is the threshold BPth
If it is greater than ', it may be determined that the degree of urgency is large.

(Emergency Determining Method Based on Steering Operation Speed) The steering operation speed d / dt (MA) is detected, and when this d / dt (MA) is larger than a predetermined threshold value MAth, the urgency level is determined. judge. Here, MA is a steering operation angle.

By such a determination method, the degree of urgency is determined from the situation of the driver's brake operation and steering operation. When the collision risk is equal to or higher than the predetermined value and the operation urgency is equal to or higher than the predetermined value, the malfunction can be reduced by operating the automatic brake. The determination of the operation urgency can be determined by any one of the above four or a combination thereof.

(Method of Actuating Brake) The conditions for starting the operation of the automatic brake are, as described above, that the degree of collision danger is equal to or higher than a predetermined value and the degree of urgency of operation is equal to or higher than a predetermined value.
Therefore, when the start condition is satisfied, the automatic brake is operated. At this time, the strength of the automatic brake is determined by the physical avoidance margin at the start of the operation. That is, in the automatic braking start point, the possible deceleration gxb = v0 ² / 2Δx such deceleration stop, at Δx distance away from the operation of the automatic brake, become vehicle speed is zero, to avoid physical collision Can be. Note that the automatic brake release condition is a case where the driver clearly performs an operation to slow down the deceleration, as shown in S10 described above.

FIG. 5 shows that td = 0.2 seconds and a0 = 0.8 g.
To obtain the stoppable distance xB, T = 1 second, gxmax =
This is an example in which the avoidable distance xS by steering is obtained with 0.4 g and the vehicle width W = 1.8 m. Thus, when the vehicle speed is 50 km / h or less, the value of xB is smaller, and above that, the value of xS is smaller. Therefore, in the case of a high speed, there are many cases where it can be avoided by steering. However, avoidance by steering is limited when there is a place that can be avoided, and when it is confirmed that the right lane is free on an expressway, for example, only when the driver turns on the blinker Processing such as taking into account this xS is performed.

FIG. 6 shows an example of a situation in which the vehicle is traveling at a speed of 60 km / h, there is an obstacle ahead, and the automatic brake is operated. In this example, it is determined that the collision risk is high when it is impossible to avoid both the brake operation and the steering in the above (iii).
That is, when both xB = 19 m and xS = 14 m become larger than Δx, the condition that the collision risk is large is satisfied. Next, as a determination of the degree of urgency, the magnitude of the deceleration was set as a determination condition, that is, gXTh = 0.4 g. Therefore, when the deceleration becomes 0.4 g or more, the automatic brake operates. However, at this time, even if the vehicle is decelerated at the maximum deceleration, the vehicle is at a distance where it cannot be stopped, so that the automatic brake generates a maximum deceleration of 0.8 g at a stretch. Although the collision is inevitable by such an operation of the automatic brake, the speed at the time of the collision can be considerably reduced. In addition,
By setting various conditions as safer conditions, it is possible to avoid collision.

[Specific method for determining operation urgency]
The operation urgency determination will be described with reference to a flowchart.

(Judgment based on time until brake depression force (or stroke, deceleration Gx, oil pressure BP: the same applies hereinafter) reaches a predetermined value) In this example, the brake depression force is BF from the time when the driver depresses the brake. (Or stroke is BS)
When the time T1 required to reach the predetermined threshold BFth (or BSth) is smaller than the predetermined threshold T1th,
It is determined that the operation urgency is high. Instead of the brake depression force BF, the time until the stroke BS, the deceleration Gx, and the oil pressure BF reach predetermined threshold values may be T1. For example, in the case of the curve in FIG. 7, the time T1 is equal to T1th
Therefore, it is determined that the operation urgency is high. On the other hand, in the case of the curve in FIG. 7, since the time T1 'is larger than T1th, it is determined that it is not urgent.

Next, specific processing will be described with reference to FIGS. First, set values td and a0
, T, b0max, and W are initialized (S101), and flag-emg and flag-cr, which are necessary flags in the processing, are initialized.
sh is set to off, and Time and Tb are set to 0 (S102). Further, T1th and BFth (or BSt), which are thresholds for the driver's operation urgency, are used.
h) is initialized (S103).

In this way, when the initial setting is completed, a signal from each sensor is input (S104). That is, own vehicle speed v0, own vehicle deceleration gx, inter-vehicle distance Δx,
A signal SWb for the relative speed Δv, the brake depression force BF (or the brake stroke BS), and the ON / OFF of the brake switch is input.

Next, the variable time for the elapsed time is updated (S105). This is the time tim
This is performed by adding the control cycle tc to e. Then, it is determined whether or not SWb is on (S106). Thereby, it is determined whether or not the driver is stepping on the brake. And when SWb is on,
It is determined whether or not SWb has changed from off to on (S
107). If Yes, tb = time is set, the time at that time is substituted for the variable tb, and the time at which the brake is depressed is stored in the variable tb (S108). If No in S107 or the time is stored in S108, it is determined whether or not time-tb is smaller than t1th. That is, it is determined whether or not the elapsed time from when the brake is depressed is equal to or less than a predetermined threshold value t1th (S109).

If the determination is Yes, it is determined whether the brake depression force BF is greater than a threshold value BFth (S110). If Yes, during the time elapsed since the brake was turned on is less than t1th,
This means that the brake depression force has fallen below the threshold value BFth, and the driver's emergency brake operation flag flag
-Emg is set to ON (S111). In this way, the operation urgency is determined, and when the operation urgency is high, the flag flag-emg indicating this is turned on. If No in S106, the flag flag-emg is set to off (S11).
2). If No in S109 and S110, the urgency level is not large, and the flag is not set in S111.

When the operation urgency is thus determined (No in S109 and S110, and when S111 and S112 are passed), the collision risk is determined next. That is, it is determined whether Δx is smaller than the stoppable distance xB (S113). In this judgment,
If Yes, the collision risk is high,
The collision danger flag flag-crsh is set to ON (S114). On the other hand, if No in S113, the collision risk is small, and the flag flag-
crsh is set to off (S115).

When the operation urgency and the collision risk are thus determined, it is determined whether the operation urgency is high and the collision risk is high (S11).
6). That is, the flag flag-emg and the flag
It is determined whether or not both -crsh are on. If the answer is Yes, the alarm is turned on (S11).
7) The required deceleration gxb is calculated and calculated (S118), and the automatic brake is operated with the obtained deceleration gxb (S11).
9). If No in S116,
Since there is no need to operate the automatic brake, the automatic brake is released (S120). In this way, S119 or S
When the process in step 120 is completed, the process returns to step S104, and the process is repeated.

As described above, according to the present embodiment, it is determined that the brake exerts a depressing force of a certain level or more within a predetermined short time, and that the driver depresses the brake rapidly.
Only when the collision risk is high, the automatic brake is activated. Therefore, the automatic brake can be controlled by the reliable determination.

[Determination by Depressing Time from Acceleration-Off to Brake-On] In the above-mentioned determination based on the time required for the brake depression force to reach a certain value, the time required for the determination is from the driver's brake on to the BFth.
(Or the stroke reaches BSth).
Here, this time T1 varies depending on the setting of BFth (or the stroke is BSth). That is, when BFth (or BSth) is set small, the time T1 becomes small, but the possibility of malfunction increases. On the other hand, BFth (or BS
If the value of th) is set to be large, the possibility of malfunction is reduced, but the time T1 is increased and the determination is delayed.

Therefore, in this embodiment, the step change time Δt from the accelerator off to the brake on is used as information, and BFth (or BSt)
h) was changed so that a judgment could be made within a time period free of malfunction and sufficient performance of the automatic brake.

Here, the setting of the BFth (or BSth) may be stored as a map so that a predetermined value is set to Δt as shown in FIG. In this example, BFth is a constant value up to a certain value, and in a subsequent constant section, the BFth rises in proportion to Δt, and then has a substantially S-shaped characteristic that becomes a constant value thereafter.

FIGS. 11 and 12 show the operation of this example.
It will be described based on. First, td, a0, T, b0max,
W is initialized (S201), and two flags flag-e
mg and flag-crsh are turned off, and variables time, tb, and ta for time are set to 0 (S202). Next, the threshold values t1th, BFth (or B
Sth) is initialized (S203). Then, signals v0, gx, Δx, Δv, BF (or BS), S
Wb and SWa are input (S204). Where SWa
Is an output signal of an accelerator switch indicating whether or not an accelerator pedal is depressed. And the variable tim
After the time is updated by adding tc to e (S205), it is determined whether or not the accelerator switch has changed from on to off (S206). If Yes, the variable ta = time is set and the time at which the accelerator is turned off is stored. If No in S206, S207 is bypassed.

Next, it is determined whether or not SWb is on. If Yes, it is determined whether or not SWb has been turned on from off (S209). If Yes, tb = t.
The time when the brake starts to be depressed is stored as im (S210). In this manner, the accelerator-off time is stored in S207 and the brake-on time is stored in S210.
The step change time Δt is calculated by b−ta (S21)
1). Then, based on Δt thus obtained,
Referring to the map in FIG. 10, BFth is calculated (S21).
2).

When the setting of the threshold value BFth is completed in this manner, the operation urgency judgment, the collision risk judgment, and the brake risk judgment are performed in the same manner as in the examples shown in FIGS. Perform control. This flow corresponds to S109 in FIG.
The description is omitted because it is exactly the same as S120.

[Judgment Method Adding BF (or BS) Change Speed] In the above two judgment methods, the operation urgency of a driver who is already in an emergency state from the time when the brake is started or the accelerator is turned off is determined. Although effective for detection, it is not suitable for detecting an emergency state (operation urgency) in which the brake must be further depressed halfway during normal brake operation. In this embodiment, the detected B
By considering the changing speed of F (or BS), an emergency state due to additional steps in the middle is detected. It should be noted that stroke BS, deceleration Gx,
The change speed of the oil pressure may be considered.

This embodiment will be described with reference to FIGS. As before, td, a
0, T, b0max, and W are initialized (S301). next,
The flags flag-emg and flag-crsh are set to off, and the variables time and t
b and ta are set to 0, count = 0 is set, and n0 is set to an initial value (S302). Next, the threshold values t1th and BFth (or B
Sth) and ΔBFth (or ΔBSth) are initialized (S3).
03). Then, the signals from the sensors, v0, gx
, Δx, Δv, BF (or BS), SWb, and SWa are input (S304). Next, the period tc is added to the time time to update the time (S305). And the variable co
Unt is incremented by 1 (S306) to enable time measurement. Next, it is determined whether or not the remainder obtained by dividing this count by a preset n0 is 0 (S30).
7). If Yes, ΔBF = (B
By F-BF _σ) / σ, seek .DELTA.Bf (S30
8). Here, σ = n0 × tc. BF is the BF at the current time, and BF _σ is σ
This is the value of the BF just before the time. Σ corresponds to this differentiation and is set smaller than the above-mentioned t1th.

[0059] Thus, when calculating the ΔBF, enter the value of the current BF to BF _sigma, keep updated the value (S309). If the answer is No in S307, S308 and 309 are bypassed. Next, SWa
Is changed from on to off (S310), and Y
If the answer is es, ta = time is set, the time when the accelerator is released is stored (S311), and it is determined whether SWb is on (S312). If SWb is on, S
It is determined whether Wb has changed from off to on. If Yes, tb = time is set, and the time the brake is depressed is stored (S314). Then, the step change time Δt =
tb-ta is calculated (S315), and a threshold value BFth is obtained based on the obtained Δt (S316). And
It is determined whether time-tb, that is, the time from depressing the brake is smaller than the threshold value t1th (S31).
7) If Yes, it is determined whether BF is larger than BFth (S318). Here, if Yes, it means that the brake depression amount has exceeded the predetermined value within the predetermined time T1th, and the flag flag-emg is set to ON (S319).

On the other hand, if No in S317, BF is not less than BFth and ΔBF is ΔBFth
It is determined whether or not this is the case (S320). If the determination is Yes, the process moves to S319, and the flag flag-emg is set to ON. As described above, when the elapsed time from the brake depression exceeds T1th, the brake depression force is equal to or more than the predetermined value BFth and the change speed ΔBF is changed to the predetermined threshold value ΔBF.
If it is not less than BFth, it is determined that the operation urgency is high. As a result, as shown in FIG. 14, when the step change amount becomes large, it is possible to determine the operation urgency. If No in S312, the flag fl is set.
The ag-emg is turned off (S321).

As described above, according to the present embodiment, the BF
(Or BS) change speed, the emergency state can be detected. Therefore, it is possible to detect an emergency state due to an increase in the brake pressure in the middle.

The determination of the collision risk and the control of the brake are the same as those in FIG.

[Change of Operating Conditions] In the above-described embodiment, when both the physical collision risk of the vehicle and the urgency of the driver's operation are satisfied (AND condition is taken), the erroneous operation of the automatic brake is performed. Operation was prevented. However, erroneous operation is reduced by the above-described determination of the operation condition, but the operation condition becomes severe, and conversely, the operation may be delayed in a situation where automatic braking is required. It is considered that this is because the criteria for the physical collision risk and the operation urgency are separately determined. Therefore, in the present embodiment, the criteria of the physical collision risk and the emergency operation degree are variably combined, and a more accurate reference is created, thereby operating the automatic brake. The configuration for this is
It is the same as the above case, and the method of calculating the collision risk and the method of determining the degree of emergency operation of the driver may be the same as the above case.

In this example, the method of calculating the degree of collision danger is the above condition (i), and the method of determining the degree of emergency operation is determined by determining that the value of the acceleration is equal to or greater than a predetermined threshold value gxth. Shows the case. As is clear from FIG. 16, the deceleration a0 required to avoid the collision with the brakes
Is large, the deceleration gxth for the driver's emergency braking operation is set small. Also, a
If 0 is in a small area, set gxth large. As a result, the automatic brake is operated in the area indicated by the circle in FIG. Here, td = 0.2 seconds, a0 = 0.8 g, gth = 0.
4 g.

That is, as shown in FIG. 16, when a deceleration exceeding the deceleration gxth for judging the driver's operation urgency is obtained, the operation urgency is determined to be large. Is smaller than the deceleration a0 required to avoid a collision, there is no need to operate the automatic brake. Then, a0 = 0.
Since 8 g and gth = 0.4 g are set, the shaded area in the drawing is determined to be dangerous in the above-described example, and is the area where the automatic brake operates.

However, in this embodiment, gxth is changed according to the size of a0. As a result, the operation area is also expanded to the area indicated by the circle in the figure of the automatic brake, and more accurate automatic brake control can be performed.

Further, in the above-described example, even if an obstacle (a ball or the like) that crosses in front of the vehicle for a moment is detected by the front monitoring sensor, the automatic brake is erroneously activated. there's a possibility that. The reason for this is
This is because the front monitoring sensor detects the size of the obstacle and the lateral movement, and does not calculate the collision risk based on the detection. Therefore, in the present invention, the obstacle detection time of the forward monitoring sensor is considered in the automatic brake operation condition.

That is, as shown in FIG. 17, when the continuous detection time of the obstacle is longer than the predetermined threshold value Δtsns, the control is performed so that the automatic brake is operated in the area of the boundary 1 in FIG. When the continuous obstacle detection time is smaller than Δtsns, the operation is performed in the area of the boundary 2 in FIG. That is, the operating condition is finally determined by adding the obstacle detection time of the forward monitoring sensor to the operating condition of the automatic brake shown in FIG. FIG. 17 shows, as an example, a case where the detection state of the obstacle has been changed from the non-detection state to the detection state and a case where the sensor state is longer than Δtsns and a case where the detection state is smaller than Δtwnw. The determination may be made based on the number of times of detection. For example, assuming that the minimum processing time unit of the sensor is τ, it is preferable to determine a time corresponding to a case where detection is performed n times or more continuously as Δtsns (tsns = nτ).

In addition to determining whether or not Δts is equal to or greater than Δtsns, Δtsns may be divided into two or more steps for the plurality of values of n.

In this way, when the passing time is short, the dangerous area which can be determined by the deceleration a0 necessary for avoiding the collision with the brake and the deceleration gxth for determining the emergency braking operation of the driver is set small. The risk of the automatic brake malfunctioning when the ball or the like jumps out can be reduced.

[0071]

As described above, according to the automatic braking system for a vehicle according to the present invention, the degree of urgency is determined from the operating state of the brake, steering and the like by the driver. And
When it is determined that the degree of urgency is high, assisting of braking by the automatic braking means is performed. When the driver's operation is urgent, the probability of the need for brake assistance is very high, and this enables highly accurate control of the automatic braking device. further,
It has a physical danger determining means, and when both the physical danger and the operation urgency are determined to be dangerous or urgent, the braking by the automatic braking means is activated to perform more accurate braking control. it can. In addition, there is urgency
Change the criteria for determining the risk according to the risk at that time
Thus, more appropriate control can be performed.

Further, by including the detection time of the obstacle as a judgment condition in the judgment means of the physical danger degree, it is possible to prevent the automatic brake from malfunctioning due to the passage of a ball or the like having a short detection time.

By including the depressing strength of the brake as a condition for judging the degree of urgency of operation, sudden braking in an emergency can be effectively detected and automatic braking can be performed.

Also, by including the time for changing over from the accelerator to the brake as a condition for judging the degree of urgency of operation, it is possible to detect that the driver has changed over quickly in an emergency and to operate the automatic braking effectively. it can.

Further, by including the steering operation speed as a condition for judging the degree of urgency of operation, it is possible to detect that the driver has tried to avoid an obstacle and perform effective braking control.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment.

FIG. 2 is a flowchart illustrating an overall operation of the embodiment.

FIG. 3 is an explanatory diagram showing a state until a vehicle stops by a brake operation.

FIG. 4 is an explanatory diagram illustrating an operation of avoiding an obstacle by a steering operation.

FIG. 5 is an explanatory diagram showing a limit of avoidance by a brake and steering operation.

FIG. 6 is an explanatory diagram showing an operation state of an automatic brake.

FIG. 7 is an explanatory diagram showing a determination based on a brake depression amount within a predetermined time.

FIG. 8 is a flowchart showing an operation when it is determined that the vehicle is urgent when the brake depressing force within a predetermined time is equal to or more than a predetermined value.

FIG. 9 is a flowchart showing an operation when it is determined that the emergency is urgent when the brake depressing force within a predetermined time is equal to or more than a predetermined value.

FIG. 10 is an explanatory diagram showing setting of a threshold value BFth of a brake depression amount.

FIG. 11 is a flowchart showing an operation of control for changing a threshold value BFth of a stepping amount according to a switching time from an accelerator to a brake.

FIG. 12 is a flowchart showing an operation of control for changing a threshold value BFth of a stepping amount according to a time for changing over from an accelerator to a brake.

FIG. 13 is a flowchart showing an operation of automatic brake control in consideration of a brake depression speed.

FIG. 14 is a flowchart showing an operation of automatic brake control in consideration of a brake depressing speed.

FIG. 15 is an explanatory diagram showing a change in a brake depression amount.

FIG. 16 is an explanatory diagram showing that the operation area of the automatic brake is changed.

FIG. 17 is an explanatory diagram showing an operation area of an automatic brake in consideration of a continuous detection time of an obstacle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle speed sensor 2 Acceleration sensor 3 Distance measuring sensor 4 Doppler sensor 5 Accelerator pedal switch 6 Brake pedal switch 7 Brake pedal force sensor 8 Brake stroke sensor 9 Steering angle sensor 10 Calculation part 11 Alarm device 12 Automatic throttle device 13 Automatic brake device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-38238 (JP, A) JP-A-5-208662 (JP, A) JP-A-5-42862 (JP, A) JP-A-6-238 1222 (JP, A) JP-A-4-121260 (JP, A) JP-A-6-179361 (JP, A) JP-A-4-57474 (JP, U) JP-A-58-15300 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60T 7/12 B60T 8/00

Claims (5)

(57) [Claims] 1. A physical danger determining means for determining a danger of a collision from a distance or a relative speed with respect to an obstacle, and an operation urgency determination for judging an urgency from a driver's operation state of a brake, a steering wheel or the like. means, and an automatic braking means for automatically performing braking when receiving a predetermined signal, the physical risk determining means is determined that there is a risk of collision with the obstacle, and the operation urgent if in degrees determining means is determined that there is urgency to the operation of the driver only, automatic braking means is operated, the control means Ru activates the full braking
In addition, as a condition for the judgment by the urgency judgment means,
Of the depressing force of the key and the depressing speed of the brake
An automatic control device for a vehicle, characterized in that at least one of them is included . 2. The collision based on the distance from the obstacle and the relative speed.
Physical danger judgment means for judging the danger, and the degree of urgency based on the operating conditions of the driver's brakes, steering wheel, etc.
Operation urgency judgment means for judging, and automatic braking for automatically braking when a predetermined signal is received
Means, and the risk of collision with an obstacle is determined by the physical risk determination means.
It is determined that there is a driver, and the driver determines
Only when it is determined that the operation of the
Control means to activate the full braking
In addition, as a condition for the judgment by the urgency judgment means,
An automatic control device for a vehicle, wherein the automatic control device includes a time for changing over from a brake to a brake . 3. The collision of the vehicle based on the distance from the obstacle and the relative speed.
The degree of danger is determined based on the physical danger judgment means for judging the danger ,
Operation urgency judgment means for judging and automatic braking for automatically braking when a predetermined signal is received
Means, and the risk of collision with an obstacle is determined by the physical risk determination means.
It is determined that there is a driver, and the driver determines
Only, automatic braking when it is determined that there is an urgency to the operation
Control means to activate the full brake
The emergency condition determining means may further include a steering condition.
An automatic control device for a vehicle, including an operation speed of a ring . 4. A device according to any one of claims 1 to 3
In the control means, the criterion for determining that there is urgency
An automatic braking device for a vehicle, wherein the automatic braking device is changed according to the degree of danger of the vehicle. 5. The apparatus according to any one of claims 1 to 3
In, as a condition of the determination in the physical risk determination means,
An automatic braking device for a vehicle, wherein a detection time of an obstacle is included.