JPH061221A - Vehicle automatic braking device - Google Patents

Abstract

(57) [Abstract] [Purpose] An alarm for giving a warning of sudden braking or slow braking is limited according to the vehicle speed of the host vehicle, and avoids contact with a front obstacle while reducing discomfort to the occupant. [Structure] Detecting the distance and relative speed between the host vehicle and an obstacle in front of it, and if it judges that there is a possibility of contact from the detection results, it issues an alarm first, then applies slow braking,
After that, it is configured to apply sudden braking. Then, the vehicle speed of the host vehicle is detected by the sensor 42, and the vehicle speed of the host vehicle is lower than the first predetermined vehicle speed and higher than the second predetermined vehicle speed by the alarm / slow braking regulation means 60 which receives a signal from the sensor 42. At vehicle speed, the warning before braking is prohibited or regulated,
When the vehicle speed of the host vehicle is lower than the second predetermined vehicle speed, both the slow braking and the warning before the sudden braking are prohibited or restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic braking system for a vehicle which automatically brakes each wheel in order to avoid contact with a front obstacle.

[0002]

2. Description of the Related Art Conventionally, as an automatic braking device for a vehicle,
For example, as disclosed in JP-A-54-33444, while continuously detecting the distance and relative speed between the host vehicle and an obstacle in front by using an optical method or ultrasonic frequency, It is known that the possibility of contact is judged from the detection result, and when there is a possibility of contact, the actuator is actuated to automatically brake each wheel and avoid contact with a front obstacle. ing.

In such an automatic braking device, it is generally practiced to give an audible warning to an occupant by giving an alarm sound before braking. In addition, in the case of the above-mentioned publication (Japanese Patent Laid-Open No. 54-33444), when it is determined that there is a possibility of contact, first, gentle braking is applied to the passenger to predict sudden braking, and then sudden braking is performed. Is disclosed.

[0004]

By the way, when the own vehicle is traveling at a relatively low vehicle speed due to road congestion or the like, the occupant is less likely to be surprised even if the automatic braking is suddenly applied. If an alarm sounds frequently or slow braking is applied in front of the passenger, there is a problem that the occupant feels uncomfortable.

The present invention has been made in view of the above points, and an object of the present invention is to limit an alarm for notifying sudden braking or slow braking according to the vehicle speed of the host vehicle so as to prevent a front obstacle. An object is to provide an automatic braking device for a vehicle that avoids contact with an object and has less discomfort for passengers.

[0006]

In order to achieve the above object, the invention according to claim 1 detects a distance and a relative speed between a host vehicle and an obstacle in front of the host vehicle, and makes contact based on the detection result. If it is determined that there is a property, in the vehicle automatic braking device configured to issue an alarm first, and then apply braking, vehicle speed detection means for detecting the vehicle speed of the own vehicle,
When the vehicle speed of the host vehicle is lower than the predetermined vehicle speed in response to the signal from the detection means, the alarm control means for prohibiting or restricting the alarm before braking is provided.

According to the second aspect of the invention, the distance and relative speed between the host vehicle and the obstacle ahead are detected, and if it is determined from the detection results that there is a possibility of contact, slow braking is performed first. In a vehicle automatic braking device configured to apply a sudden braking after that, when a vehicle speed detection means for detecting the vehicle speed of the own vehicle and a signal of the detection means are received and the vehicle speed of the own vehicle is lower than a predetermined vehicle speed, It is configured to include a slow braking control unit that prohibits or controls the slow braking before the sudden braking.

According to the third aspect of the invention, the distance and the relative speed between the host vehicle and the obstacle ahead are detected, and when it is determined that there is a possibility of contact from the detection result, an alarm is first issued. In an automatic braking device for a vehicle, which is configured to apply slow braking and then sudden braking, a vehicle speed detecting means for detecting the vehicle speed of the own vehicle and a vehicle speed of the own vehicle by receiving a signal from the detecting means. Is prohibited or restricted when the vehicle speed is lower than the first predetermined vehicle speed and higher than the second predetermined vehicle speed, and when the vehicle speed of the host vehicle is lower than the second predetermined vehicle speed, slow braking before the sudden braking and An alarm / slow braking restricting means for prohibiting or restricting both alarms is provided.

[0009]

With the above construction, in the invention according to claim 1,
When it is determined that there is a possibility of contact with a front obstacle when the vehicle speed of the host vehicle is higher than a predetermined vehicle speed, an alarm is first issued and then braking is applied. On the other hand, when it is determined that there is a possibility of contact with the front obstacle when the vehicle speed of the host vehicle is lower than the predetermined vehicle speed, the alarm is prohibited or restricted by the alarm restricting means, and the braking is immediately applied without the alarm,
Alternatively, the number of warnings before braking is reduced.

According to the second aspect of the invention, when it is determined that there is a possibility of contact with the front obstacle when the vehicle speed of the host vehicle is higher than the predetermined vehicle speed, the slow braking is applied first, and then the rapid braking is applied. . On the other hand, when it is determined that there is a possibility of contact with the front obstacle when the vehicle speed of the host vehicle is lower than the predetermined vehicle speed, the alarm restriction unit prohibits or restricts the slow braking, so that the quick braking does not occur. The number of times of immediate braking or gentle braking before sudden braking is reduced.

According to the third aspect of the present invention, when it is determined that there is a possibility of contact with a front obstacle when the vehicle speed of the host vehicle is higher than the first predetermined vehicle speed, that is, when the vehicle speed is high, an alarm is issued first. Then, slow braking is applied, and then sudden braking is applied. When the vehicle speed of the host vehicle is lower than the first predetermined vehicle speed and is higher than the second predetermined vehicle speed, that is, when it is determined that there is a possibility of contact with a front obstacle at the middle vehicle speed, an alarm / pre-braking warning is issued by the slow braking control means. Is prohibited or regulated,
Without alarm, braking (slow braking and sudden braking) will be applied immediately,
Alternatively, the number of warnings before braking is reduced. Further, when it is determined that the vehicle speed of the host vehicle is lower than the second predetermined vehicle speed, that is, when the vehicle speed is low, it is determined that there is a possibility of contact with a front obstacle, the alarm / slow braking restricting means prohibits the slow braking and the alarm before braking. Or, by being restricted, sudden braking is applied immediately without both warning and slow braking, or the number of warnings and slow braking before rapid braking is reduced.

[0012]

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

1 and 2 show an automatic braking device for a vehicle according to an embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram of the automatic braking device, and FIG. 2 is a block diagram of the automatic braking device. Is.

In FIG. 1, reference numeral 1 is a master back for increasing a pedaling force of a brake pedal 2 by a driver, and 3 is a master cylinder for generating a brake pressure according to the pedaling force increased by the master back 1, The brake pressure generated in the master cylinder 3 is first sent to the hydraulic actuator unit 4 of the automatic braking device, and then the hydraulic actuator unit 5 of the antiskid brake device (ABS).
Is supplied to each brake device 6 of four wheels (only one wheel is shown in the figure).

The hydraulic actuator section 4 of the automatic braking device has a shutter valve 11, a pressure increasing valve 12 and a pressure reducing valve 13 for cutting off the communication between the master cylinder 3 and the brake device 6 side. One valve 1
All of 1 to 13 are electromagnetic 2-port 2-position switching valves. Between the pressure increasing valve 12 and the master cylinder 3, a motor-driven oil pump 14 and the oil pump 1 are provided.
And an accumulator 15 for storing the pressure oil discharged from No. 4 and keeping it at a constant pressure. When the shutter valve 11 is in the open position, the brake device 6 for each wheel is driven according to the depression force of the brake pedal 2.
Brakes on. On the other hand, when the shutter valve 11 is in the closed position, the pressure increasing valve 12 is in the open position and the pressure reducing valve 1 is in the open position.
When 3 is switched to the closed position, the pressure oil from the accumulator 15 is supplied to the brake device 6 of each wheel to increase the brake pressure, and the pressure increasing valve 12 is closed and the pressure reducing valve 13 is opened. When they are switched, the pressure oil is returned from the brake device 6 to reduce the brake pressure.

The ABS hydraulic actuator section 5 has a 3-port 2-position switching valve 21 provided for each wheel, and is applied to each brake device 6 by switching the valve 21 during ABS operation. The brake pressure is controlled to prevent each wheel from locking. Although the structure of the hydraulic actuator section 5 is not described in detail, in addition to the switching valve 21, a motor-driven oil pump 22 and accumulators 23 and 24 are provided. The brake device 6 for each wheel includes a disk 26 that rotates integrally with the wheel, and a caliper 27 that receives the brake pressure from the master cylinder 3 side and clamps the disk 26.

On the other hand, in FIG. 2, reference numeral 31 is an ultrasonic radar unit provided in the front portion of the vehicle body. The ultrasonic radar unit 31 is not shown in detail in the drawing, but as is well known, the ultrasonic wave is emitted from the transmitting portion. While transmitting to an obstacle such as a vehicle in front of the own vehicle, the receiving section receives the reflected wave reflected by hitting the front obstacle,
Operation unit 32 for receiving signals from this radar unit 31
Is configured to calculate the distance and relative speed between the host vehicle and an obstacle ahead of the vehicle based on the delay time from the time when the radar received wave is transmitted. Reference numerals 33 and 34 denote a pair of radar head units respectively provided on the left and right of the front part of the vehicle body, and each of the radar head units 33 and 34 transmits a pulse laser beam from an emission unit toward an obstacle in front of the vehicle. In addition, the reception unit receives the reflected light reflected by the front obstacle, and the calculation unit 32
Receives signals from these radar head units 33 and 34 through a signal processing unit 35, and calculates a distance and a relative speed between the host vehicle and a front obstacle according to a delay time from a transmission time point of the laser reception light. It has become. Then, the calculation unit 32 uses the radar head units 33, 3
Priority is given to the calculation results of distance and relative speed by the system of 4,
The calculation result of the distance and the relative speed by the system of the ultrasonic radar unit 31 is used as an auxiliary, and the distance between the host vehicle and the front obstacle and the distance for detecting the relative speed are detected. The relative speed detecting means 36 is configured.

The transmission / reception direction of the pulsed laser light by both the radar head units 33, 34 is provided so that it can be changed in the horizontal direction by a motor 37.
The operation of is controlled by the arithmetic unit 32. Reference numeral 38 denotes an angle sensor for detecting the transmission / reception direction of the pulsed laser light from the rotation angle of the motor 37. The detection signal of the angle sensor 38 is input to the arithmetic unit 32, and the radar head unit 33, The transmission / reception direction of the pulsed laser light is added to the calculation of the distance and the relative speed by the system of 34.

Reference numeral 41 denotes a rudder angle sensor for detecting the rudder angle,
42 is a vehicle speed sensor as a vehicle speed detecting means for detecting the vehicle speed of the own vehicle (own vehicle speed), 43 is a front-rear G sensor for detecting longitudinal acceleration (front-rear G) of the vehicle, and 44 is a friction coefficient (μ) of the road surface. It is a road surface μ sensor, and the detection signals of these various sensors 41 to 44 and the signals of the distance and the relative speed between the own vehicle and the front obstacle obtained by the calculation unit 32 are input to the control unit 45. It The control unit 45
Judges whether there is a possibility of contact between the host vehicle and the front obstacle based on the distance and relative speed between the host vehicle and the front obstacle, and determines that there is a possibility of contact. Occasionally, an operation signal is output to the hydraulic actuator unit 4 of the automatic braking device so that the brakes are automatically applied to each wheel so as to avoid contact. Reference numeral 46 denotes an alarm display unit provided on an instrument panel in the vehicle compartment. The alarm display unit 46 includes the control unit 4
An alarm buzzer 47 and a distance display unit 48 are provided for receiving signals from 5 respectively.

As shown in FIG. 3, the control unit 45 receives signals from the arithmetic unit 32 and the vehicle speed sensor 42 and sets a safe inter-vehicle distance L0 between the host vehicle and the preceding vehicle.
It has a safe inter-vehicle distance setting unit 51. Here, the safe inter-vehicle distance L0 refers to an inter-vehicle distance that is unlikely to come into contact with the preceding vehicle by the host vehicle, and does not require not only braking but also activation of the alarm buzzer 47 to warn the driver. In setting the safe inter-vehicle distance L0, a threshold map as shown in FIG. 4 which is previously stored in the setting unit 51 is used.

In the threshold map shown in FIG. 4, a threshold line A indicates that a front vehicle as a front obstacle avoids contact with an obstacle ahead of the front vehicle when the vehicle stops. It indicates the vehicle-to-vehicle distance required to do so, and is always the same as when the front obstacle is a stationary object (that is, when the relative speed V1 is the same as the own vehicle speed v0) regardless of the magnitude of the relative speed V1. It takes a value (numeric expression v0 ² / 2μg). The threshold line B indicates the inter-vehicle distance (numerical expression V1. (2v0-V1) / 2 .mu.g) necessary for avoiding contact with this vehicle when the vehicle ahead is suddenly braked, and the threshold line C Indicates the inter-vehicle distance required to avoid contact with the preceding vehicle when the preceding vehicle is subjected to slow braking of deceleration μ / 2g, and the threshold line D indicates this vehicle when the preceding vehicle maintains a constant vehicle speed. shows the inter-vehicle distance (numeric expression V1 ^2/2 [mu] g) required to avoid contact with. Furthermore, the threshold line E is
Even if the host vehicle brakes, contact with the vehicle in front cannot be avoided, but the inter-vehicle distance that can reduce the impact force at the time of contact is shown.
When the threshold line is on the horizontal axis (that is, when the threshold L is always zero), the automatic braking is not applied and this is canceled.

Then, the first safety inter-vehicle distance setting section 51.
Selects one threshold line from the above-mentioned five types of threshold lines A to E according to the driving state of the vehicle, and at this threshold line, the own vehicle and the front obstacle (front vehicle ) And the threshold value L corresponding to the relative speed V1. For example,
By selecting the threshold line B when the host vehicle speed v0 is a high vehicle speed, the threshold value D when the host vehicle speed v0 is a medium vehicle speed, and the threshold line E when the host vehicle speed v0 is a low vehicle speed. Is higher, the threshold value L0 of the possibility of contact is changed to a larger value. The safe inter-vehicle distance L0 is set by multiplying the threshold value L calculated as described above by a predetermined value.

Further, in FIG. 3, reference numeral 52 is a burst time detecting means for detecting that the wheels are bursting. Specifically, the burst time detecting means 52 is a rotation of each wheel detected by a sensor. The speeds (that is, wheel speeds) are compared with each other, and when the wheel speed of one wheel shows an irregular value as compared with that of the other wheel, it is determined that the wheel is in a burst time. Reference numeral 53 denotes auxiliary tire use detecting means for detecting that one wheel uses an auxiliary tire having a diameter smaller than that of a normal tire, and the auxiliary tire use detecting means detects the burst time. As in the case of the means 52, specifically, the rotational speeds of the wheels (that is, the wheel speeds) detected by the sensors are compared with each other, and when the wheel speed of one wheel shows a value smaller than that of the other wheels by a certain amount. It is now decided to use auxiliary tires. 54
Is wear detecting means for detecting that a brake pad (not shown) of the brake device 6 of each wheel is worn by a predetermined amount or more, and 55 is tire pressure detecting means for detecting tire pressure of each wheel. The detection signals of the detection means 52 to 55 are all corrected distance calculation unit 5 provided in control unit 45.
6 is input. The correction distance calculation unit 56 calculates the correction distance α according to the wheel burst, the use of the auxiliary tire, the wear state of the brake pad, and the tire pressure. Correction distance α calculated by the correction distance calculation unit 56
Is sent to the second safety inter-vehicle distance setting unit 57, and the setting unit 5
In step 7, it is added to the safe inter-vehicle distance L0 set by the first safe inter-vehicle distance setting unit 51. This added value is set as the final safe inter-vehicle distance L0.

The control unit 45 controls the inter-vehicle distance at the present time between the host vehicle and the preceding vehicle, which is calculated by the calculation unit 32 (hereinafter,
A contact possibility determination for determining the possibility of contact between the host vehicle and the preceding vehicle by comparing L1 (referred to as the current inter-vehicle distance) and the safe inter-vehicle distance L0 set by the second safety inter-vehicle distance setting unit 57. When the determination unit 58 determines that there is a possibility of contact, the alarm buzzer 47 is first output based on the operation signal output from the operation command unit 59.
Is activated to give an alarm, and then the actuator section 4 is activated to apply gentle braking, and then sudden braking is applied. Here, the sudden braking means applying the brake at the maximum deceleration (about 0.8 G), and the slow braking means the deceleration lower than the maximum deceleration (about 0.3 to 0.4).
G) means to apply a constant brake. The distance at which the alarm is issued corresponds to the safe inter-vehicle distance L0. In the case of the present embodiment, the slow braking distance is the safe inter-vehicle distance L0 multiplied by 0.6, and the sudden braking is applied. The distance is a distance obtained by adding 0.4 to the safe inter-vehicle distance L0 (see FIG. 7).

The control unit 45 further includes the vehicle speed sensor 4
The alarm / slow braking restricting means 60 receives the detection signal from the control signal 59, and the alarm / slow braking restricting means 60 instructs the operation command section 59 that the vehicle speed v0 is the first predetermined vehicle speed (for example, 80 km). / H) and a second predetermined vehicle speed (eg 3
When the vehicle speed v0 is lower than the second predetermined vehicle speed, both the slow braking and the warning before the sudden braking are prohibited when the vehicle speed v0 is lower than the second predetermined vehicle speed.

FIGS. 5 and 6 are flow charts showing a method of calculating the correction distance α in the correction distance calculating unit 56, and FIG. 7 is a control of automatic braking by the contact possibility judging unit 58, the operation commanding unit 59 and the like. It is a flowchart figure which shows a flow.

In FIGS. 5 and 6, after the start,
First, the signal is read (step S1). After that, it is determined whether or not the wheel is in a burst time (step S2). Then, it is determined whether or not the auxiliary tire is in use (step S3 or S18), and whether or not the brake pad is worn by a predetermined amount or more (step S4, S11, S19 or S26). Further, it is judged whether or not the tire pressure of the wheel is reduced (steps S5 and S8).
, S12, S15, S20, S23, S27 or S30).

Then, depending on the above-mentioned four judgment results, a predetermined value α1 to α15 or zero is substituted for the correction distance α (steps S6, S7, S9, S10, S13, S14, S1).
6, S17, S21, S22, S24, S25, S28, S29, S31
Or S32), and then returns. Here, there is the following magnitude relationship between the predetermined values α1 to α15.

0 <α15 <α14 <α13 <α12 <α11 <α10 <α9 <α8 α8 <α7 <α6 <α5 <α4 <α3 <α2 <α1 Therefore, the calculation method of the correction distance α in the correction distance calculation unit 56 is The higher the degree to which the vehicle tends to be unstable during braking due to wheel burst, use of auxiliary tires, wear of brake pads, and reduction of tire pressure, the longer the correction distance α.

In FIG. 6, after starting, the signal is first read in step S41, and it is determined in step S42 whether the current inter-vehicle distance L1 is shorter than the safe inter-vehicle distance L0. When the determination is NO, the routine directly returns. On the other hand, when the determination is YES, it is determined in step S43 whether or not the host vehicle speed v0 is at a high vehicle speed of 80 km / h or higher as the first predetermined vehicle speed.

When the determination in step S43 is YES, that is, when the vehicle speed is high, it is determined in step S44 whether the current inter-vehicle distance L1 is longer than the gentle braking start distance obtained by adding 0.6 to the safe inter-vehicle distance L0. If this determination is YES, the alarm buzzer 47 is activated to issue an alarm in step S45, and thereafter the process returns. On the other hand, when the determination is NO, in step S46, the current inter-vehicle distance L1 is 0.4 to the safe inter-vehicle distance L0.
Is determined whether it is longer than the sudden braking start distance,
If the determination is YES, the hazard is lit at step S47 and the slow braking is applied at the same time, while if the determination is NO, the hazard is lit at the step S48 and the sudden braking is applied at the same time. After applying this gentle braking or sudden braking, the process returns.

When the determination in step S43 is NO, it is further determined in step S49 whether the host vehicle speed v0 is a medium vehicle speed of 30 km / h or more as the second predetermined vehicle speed. When the determination is YES at medium vehicle speed, it is determined in step S50 whether the current inter-vehicle distance L1 is longer than the slow braking start distance obtained by adding 0.6 to the safe inter-vehicle distance L0. If this determination is YES, the process directly returns. On the other hand, if the determination is NO, it is determined in step S51 whether the current inter-vehicle distance L1 is longer than the sudden braking start distance obtained by adding 0.4 to the safe inter-vehicle distance L0. If the determination is YES, step S52 On the other hand, when the determination is NO, while the slow braking is applied at step S53, the hazard is turned on at the same time and the rapid braking is applied at the same time. After applying this gentle braking or sudden braking, the process returns.

Further, when step S49 is NO, that is, when the vehicle speed v0 is a low vehicle speed less than 30 km / h, the current inter-vehicle distance L1 is changed to the safe inter-vehicle distance L0 in step S54.
Is determined to be longer than the sudden braking start distance, and if the determination is YES, the routine directly returns, while if the determination is NO, the rapid braking is applied in step S55, and then the procedure returns. .

Next, to explain the operation and effect of the above embodiment, when the vehicle speed v0 is a high vehicle speed of 80 km / h or more, the current vehicle-to-vehicle distance L1 between the vehicle and the preceding vehicle becomes shorter than the safe vehicle-to-vehicle distance L0. When it is determined that there is a possibility of contact, the alarm buzzer 47 is activated first to issue an alarm. When the current inter-vehicle distance L1 is further shortened, gentle braking is applied subsequently, and then sudden braking is applied.

In addition, the vehicle speed v0 is lower than 80 km / h and 3
If the current inter-vehicle distance L1 between the own vehicle and the preceding vehicle becomes shorter than the safe inter-vehicle distance L0 at a medium vehicle speed higher than 0 km / h, and it is determined that there is a possibility of contact, no alarm is issued. Slow braking is applied when the current inter-vehicle distance L1 becomes shorter than the slow braking start distance, and sudden braking is applied when the current inter-vehicle distance L1 becomes shorter.

Further, when the own vehicle speed v0 is lower than 30 km / h and the low vehicle speed is lower than the current vehicle distance L0 between the own vehicle and the preceding vehicle, it is judged that there is a possibility of contact. , No alarm is issued and no gentle braking is applied. Sudden braking is applied when the current inter-vehicle distance L1 becomes shorter than the sudden braking start distance.

As described above, the operation sequence of the alarm, the slow braking and the sudden braking when the possibility of contact is determined is changed according to the own vehicle speed v0. It is possible to prevent the alarm and the slow braking from frequently operating while surely preventing the above, and it is possible to prevent the driver and other occupants from feeling uncomfortable.

In addition, in the above embodiment, the higher the degree to which the vehicle is likely to be in an unstable state during braking due to wheel burst, use of auxiliary tires, wear of brake pads and reduction of tire pressure, the greater the degree is. The correction distance α is added to the safe inter-vehicle distance L0 so that the alarm and the braking are activated at an early stage, so that the contact with the vehicle in front can be more reliably prevented and the safety can be sufficiently ensured. Can be planned.

The present invention is not limited to the above embodiment, but includes various other modifications.
For example, in the above embodiment, at the time of low vehicle speed or medium vehicle speed, the current inter-vehicle distance L1 between the host vehicle and the preceding vehicle is the safe inter-vehicle distance L0.
The alarm or slow braking is prohibited even when it is determined that there is a possibility of contact, but instead of prohibiting, the present invention changes the alarm or slow braking operation start distance to a longer value. Therefore, these operations may be restricted.

Further, in the above-mentioned embodiment, when it is judged that there is a possibility of contact, the present invention is applied to an automatic braking device constructed so that an alarm is issued first, followed by gentle braking and then sudden braking. However, according to the present invention, when it is determined that there is a possibility of contact, an alarm is first issued, and then an automatic braking device for a vehicle configured to apply braking, or a slow braking is applied first. The same can be applied to an automatic braking device that is configured to apply and then apply sudden braking. In the former case, the warning before braking may be prohibited or restricted when the host vehicle speed is lower than the predetermined vehicle speed, and in the latter case, slow braking before the sudden braking may be prohibited or restricted when the host vehicle speed is lower than the predetermined vehicle speed. do it.

[0041]

As described above, according to the first aspect of the present invention, when it is determined that there is a possibility of contact with a front obstacle when the vehicle speed is low, no alarm is given and braking is immediately applied. Alternatively, since the number of warnings before braking is reduced, it is possible to prevent a passenger from feeling uncomfortable due to frequent warnings while avoiding contact with a front obstacle.

According to the second aspect of the invention, when it is determined that there is a possibility of contact with a front obstacle when the vehicle speed is low, there is no gentle braking, and sudden braking is applied immediately or sudden braking is applied. Since the number of times of gentle braking before braking is reduced, it is possible to prevent a passenger from feeling uncomfortable due to frequent gentle braking while avoiding contact with a front obstacle.

Further, according to the third aspect of the invention, when it is determined that there is a possibility of contact with a front obstacle at a medium vehicle speed, braking is immediately applied without alarm, or the number of alarms before braking is increased. When it is determined that there is a possibility of contact with a front obstacle at low vehicle speed, sudden braking will be applied immediately without both warning and slow braking, or the number of warnings and slow braking before rapid braking will be low. As a result, frequent alarms and slow braking can be appropriately suppressed according to the vehicle speed, and the discomfort can be suppressed more appropriately.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of an automatic braking device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram of an automatic braking device.

FIG. 3 is a block configuration diagram of a control unit.

FIG. 4 is a diagram showing a map for calculating a contact avoidance threshold value.

FIG. 5 is a flowchart showing a method of calculating a correction distance.

FIG. 6 is a flowchart of the same.

FIG. 7 is a flowchart showing a control flow of automatic braking.

[Explanation of symbols]

 36 distance / relative speed detection means 42 vehicle speed sensor (vehicle speed detection means) 45 control unit 60 alarm / slow braking regulation means

Claims (3)

[Claims] 1. When a distance and a relative speed between an own vehicle and an obstacle in front of the vehicle are detected, and when it is determined that there is a possibility of contact based on the detection result, an alarm is issued first, and then braking is applied. In the automatic braking device for a vehicle configured as described above, vehicle speed detection means for detecting the vehicle speed of the own vehicle, and a signal from the detection means, and when the vehicle speed of the own vehicle is lower than a predetermined vehicle speed, the pre-braking warning is prohibited or An automatic braking device for a vehicle, comprising an alarm regulating means for regulating. 2. When the distance and relative speed between the host vehicle and an obstacle ahead are detected, and it is determined from the detection results that there is a possibility of contact, slow braking is applied first, and then sudden braking is applied. In an automatic braking device for a vehicle configured to apply a vehicle speed, a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, and a signal from the detecting means, when the vehicle speed of the own vehicle is lower than a predetermined vehicle speed, An automatic braking device for a vehicle, comprising: a slow braking restricting means for prohibiting or restricting braking. 3. The distance and relative speed between the host vehicle and an obstacle in front of the vehicle are detected, and when it is determined that there is a possibility of contact from the detection result, an alarm is issued first, and then slow braking is performed. In an automatic braking device for a vehicle configured to apply and then suddenly apply braking, a vehicle speed detecting means for detecting a vehicle speed of the own vehicle, and a vehicle speed of the own vehicle when receiving a signal from the detecting means. When the vehicle speed is lower and higher than the second predetermined vehicle speed, the warning before braking is prohibited or regulated, and the vehicle speed of the host vehicle is the second speed.
When the vehicle speed is lower than the predetermined vehicle speed, the automatic braking device for a vehicle is provided with an alarm / slow braking restricting means for prohibiting or restricting both the slow braking and the alarm before the sudden braking.