JPH05240075A - Automatic braking device of vehicle - Google Patents

Abstract

PURPOSE:To avoid a danger without fail as performing a vehicle's decelerating action gently and comfortably without feeling a sense of incompatibility by operating an engine brake and a hydraulic brake in combination according to the degree of risk at a time when the driver's be made contact with an obstacle. CONSTITUTION:An automatic braking control unit 49 drives and controls a brake pressure regulating mechanism 54 of a brake hydraulic system 52 independently of operation of a brake pedal 50. In addition, it controls an automatic transmission control unit 33, a sub-throttle valve controller 48, an injection valve controller 58 and a traction control unit 103 respectively via an overall control unit 113. In this case, at a time when the driver's own car might be made contact with an obstacle but the degree of risk is low, an engine brake is operated and then a hydraulic brake is operated at need, thereby avoiding any possible danger. On the other hand, when the dangerous degree is high, the engine brake is produced while the hydraulic brake is operated, thus any possible danger is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the distance and relative speed between an own vehicle and an obstacle, judges the possibility of contact from the detection result, and automatically generates a braking force. The present invention relates to a vehicle automatic braking device.

[0002]

2. Description of the Related Art Conventionally, as an automatic braking device for a vehicle of this type, an optical method or an ultrasonic wave is disclosed as disclosed in, for example, Japanese Patent Publication Nos. 39-2565 and 39-5668. It continuously detects the distance and relative speed between the host vehicle and the obstacle in front of it, and the possibility of contact from the detected distance and relative speed between the host vehicle and the obstacle in front. If there is a possibility of contact, it is known that the actuator is operated to automatically brake each wheel to prevent contact. There is.

[0003]

However, in the above-described conventional automatic braking device, when it is determined that there is a possibility of contact between the vehicle and the front obstacle, the actuator is actuated to operate each wheel. It is configured to apply the brake automatically. Therefore, for example, when another vehicle or a person suddenly jumps out between the host vehicle and the front obstacle, the suddenly jumping out vehicle or person may be recognized as a new front obstacle. However, in such a case, the distance between the new front obstacle and the own vehicle is extremely short, and the probability of contact with the front obstacle cannot be covered by the normal automatic danger avoidance operation. It may increase.

On the other hand, assuming such a case, if the sudden braking is configured to be activated in the automatic danger avoiding operation, the relationship with the front obstacle is judged to be a normal dangerous state. Even in such a case, the sudden braking will be automatically activated. For this reason, the driver feels a strong sense of deceleration and a great sense of discomfort, even though he / she does not depress the brake pedal. Further, in some cases, the driver may feel a deceleration shock, and improvement is desired.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to judge the degree of danger even when it is judged that the vehicle may come into contact with a front obstacle. When the risk is low, a gentle deceleration operation is executed, and when the risk is high, a rapid deceleration operation is executed to prevent the driver from feeling uncomfortable. It is to provide.

[0006]

In order to solve the above-mentioned problems and achieve the object, an automatic braking device for a vehicle according to the present invention according to claim 1 has a distance between the vehicle and an obstacle and A contact possibility determination that determines whether or not there is a possibility that the own vehicle may come into contact with the obstacle from the detection means that detects the relative speed, the distance between the own vehicle and the obstacle detected by this detection means, and the relative speed If there is a possibility of contact between the means and the determination means, but the degree of danger is low, first, the engine is automatically controlled to generate engine braking, and then the brake hydraulic system is activated as necessary. When the first risk avoiding means for controlling the vehicle to exert the braking force and the judging means judge that the risk of the possibility of contact is high, the engine is automatically controlled to apply the engine braking. Along with A second danger avoiding means for controlling a brake hydraulic system to exert a braking force, wherein the first danger avoiding means controls the engine with a first engine control content, and the second risk avoiding means is provided. The means controls the engine with a second engine control content different from the first engine control content.

Further, in the automatic braking device for a vehicle according to a second aspect of the present invention, the first engine control content is that the intake passage is first closed and driven, and after the intake passage is fully closed, Is cut off, and the second engine control content is set so that the intake passage is closed and driven, and the supply of fuel is cut off.

According to a third aspect of the present invention, there is provided an automatic braking device for a vehicle according to the invention, wherein the own vehicle is provided with an automatic transmission, and the first danger avoiding means has a first automatic transmission control content. It is characterized in that the automatic transmission is controlled, and the second danger avoiding means controls the automatic transmission with a second automatic transmission control content different from the first automatic transmission control content.

According to a fourth aspect of the present invention, there is provided an automatic braking device for a vehicle according to the invention, wherein the automatic transmission includes a lock-up clutch, and the first automatic shift control content is to loosen the lock-up clutch. The second automatic shift control content is set so that the lockup clutch is engaged immediately, and the second automatic shift control content is set so that the lockup clutch is immediately engaged.

According to a fifth aspect of the present invention, there is provided an automatic braking apparatus for a vehicle according to the invention, wherein the automatic transmission is configured so that a shift gear position can be fixed. The gear position is set so as to be gently fixed, and the content of the second automatic shift control is set so as to immediately fix the shift gear position.

According to a sixth aspect of the present invention, there is provided an automatic braking apparatus for a vehicle according to the present invention, wherein the judging means changes in a direction in which the distance between the own vehicle and a front obstacle is continuously shortened. If it is determined that the risk is low, it is determined that the distance between the vehicle and the front obstacle is discontinuously shortened. The feature is that it is configured to judge that is high.

[0012]

With the above construction, according to the invention described in claim 1, the engine control contents are set differently according to the degree of danger occurring between the front obstacle and the host vehicle. The danger avoidance operation described above is executed, and it is possible to effectively suppress the driver's discomfort caused by the deceleration operation accompanying the risk avoidance. According to the second aspect of the present invention, the first engine control content when it is determined that the degree of risk is low is that the intake passage is first driven to be closed, and after the intake passage is fully closed, the fuel Supply cut, so
The engine brake is gradually activated, and the driver only feels a gentle deceleration. On the other hand, the second engine control content when it is judged that the degree of risk is high is the closing drive of the intake passage and the fuel supply. Since the cutting and the cutting are performed at substantially the same time, the engine braking is immediate and
It will be activated strongly.

According to the third aspect of the invention, the content of the automatic shift is set to be different depending on the degree of danger occurring between the vehicle equipped with the automatic transmission and the front obstacle. Since the danger avoidance operation is executed, it is possible to more effectively suppress the driver's discomfort caused by the deceleration operation accompanying the danger avoidance. According to the invention described in claim 4, the first automatic transmission control content when it is determined that the degree of risk is low is set so that the lock-up clutch is slowly engaged, and The second automatic transmission control content when the deceleration shock to the vehicle is eased and the risk is judged to be high is set so that the lock-up clutch is immediately engaged, and a rapid deceleration state is set. It can be achieved.

According to the fifth aspect of the invention, when it is determined that the distance between the vehicle and the front obstacle is continuously decreasing, the front obstacle is detected. If the object recognized as is approaching with the same as it is, it is determined that the risk is low, and if it is changing in a direction that shortens discontinuously, in the case of a previous obstacle, An object that is newly recognized as a front obstacle is suddenly entering, and it is determined that the degree of danger is high.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of an automatic braking system for a vehicle according to the present invention will be described in detail below with reference to the accompanying drawings. In this embodiment, the vehicle is equipped with an automatic transmission. As shown in FIG. 1, in a vehicle A provided with the automatic braking device 10 of this embodiment, the left and right front wheels 12FL and 12FR are driven wheels, and the left and right rear wheels 12 are provided.
RL and 12RR are drive wheels. That is, the drive torque generated by the engine 14 mounted on the front part of the vehicle body sequentially passes through the automatic transmission 16, the propeller shaft 18, and the differential gear 20, and then the left and right drive shafts 22L, 22R.
Is transmitted to the left and right rear wheels 12RL and 12RR, respectively.

The above-mentioned automatic transmission 16 is composed of a torque converter 24 and a multi-stage transmission gear mechanism 26. The shift operation in the automatic transmission 16 is performed by changing the combination of the excitation and demagnetization of the plurality of solenoids 28 incorporated in the hydraulic circuit of the transmission gear mechanism 26. Further, the torque converter 24 includes a hydraulically operated lock-up clutch 30, and the lock-up clutch 30 is engaged by switching between excitation and demagnetization of a solenoid 32 incorporated in a hydraulic circuit of the lock-up clutch 30. And the cancellation of the fastening are executed respectively.

On the other hand, the solenoids 28 and 32 described above are
The automatic transmission control unit (CAT) 33 for controlling the automatic transmission 16 is connected to and controlled by the automatic transmission control unit (CAT) 33. This automatic transmission control unit (CA
T) 33 has a gear change characteristic and a lock-up characteristic stored in advance in a known manner, and the gear change control and the lock-up control are executed in the automatic transmission 16 based on these characteristics. Control. For this control, the automatic transmission control unit (CAT) 33 includes a main throttle opening sensor 36 for detecting the throttle opening of the main slot valve 34 and a sub throttle valve 38 as shown in FIG. Sub-throttle opening sensor 4 for detecting opening
0 is connected to a vehicle speed sensor 42 for detecting the vehicle speed, and a main throttle opening signal, a sub-throttle opening signal, and a vehicle speed signal are input from these. Incidentally, in this embodiment, the vehicle speed sensor 4
2 is configured to calculate the current vehicle speed based on the rotation speed of the propeller shaft 18.

Here, as shown in FIG. 1, the sub-throttle valve 38 and the main throttle valve 34 described above are sequentially provided in the intake passage 44 along the flow direction of the intake air, that is, the sub-throttle valve. The throttle valve 38 is provided on the air cleaner side (not shown), and the main throttle valve 34 is provided on the engine 14 side. The main throttle valve 34 is mechanically connected to an accelerator pedal 46, and the main throttle valve 34 is driven to open and the intake passage 44 is opened according to the amount of depression of the accelerator pedal 46 by the driver. In other words, the main throttle opening is set to be large. On the other hand, the sub throttle valve 38 is the sub throttle valve controller 4
8 is connected, and the drive is controlled thereby. And this sub throttle valve controller 48
Is connected to an automatic braking control unit (CAB) 49 that controls the control system of the automatic braking device 10 of this embodiment, and is driven and controlled by this. That is, the sub-throttle valve 38 is electrically driven and controlled under the control of the automatic braking control unit (CAB) 49 via the sub-throttle valve controller 48 while being independent of the main throttle valve 34. There is.

That is, this automatic braking control unit (CA
B) 49, whose control procedure will be described in detail later, basically describes a brake pressure adjusting mechanism 54 provided in the brake hydraulic system 52 regardless of the driver's depression of the brake pedal 50. In addition to the basic automatic braking control, the drive control is performed on the injection valve controller 58 that drives the fuel injection valve 56 regardless of the fuel injection control based on the operating state, and the sub throttle valve controller is also used. The throttle opening degree of the sub-throttle valve 38 is changed and controlled via 48, and further the automatic transmission 16 is controlled via the automatic transmission control unit (CAT) 33 described above.
Is configured to control the gear shifting operation of.

The automatic braking control unit (CAB) 49
When the automatic transmission control unit (CAT) 33 is controlled during the automatic braking control operation by, the automatic transmission control unit (CAT) 33 is once issued at present to execute the control operation according to the shift gear position. After reading the running range position information and the shift gear position information, the engine automatic braking control operation is executed according to the read running range position information and the read shift gear position information. The engine automatic braking control operation will be described in detail later.

Next, the configuration of the above-mentioned brake hydraulic system 52 and the configuration of the brake pressure adjusting mechanism 54 connected to this brake hydraulic system will be described with reference to FIGS. 1 and 2, respectively. First, as shown in FIG. 1, each wheel 12FL, 12F
Brake device 60FL, R, 12RL, 12RR
60FR, 60RL, and 60RR are provided, respectively.
Brake devices 60FL, 60FR, 60RL, 60R
R is the corresponding wheel 12FL, 12FR, 12RL, 1
A caliper (brake cylinder) 64FL, 64FR, 64RL, 64RR that exerts braking force by hydraulic pressure by sandwiching the brake discs 62FL, 62FR, 62RL, 62RR mounted so as to rotate integrally with the 2RR.
Are equipped with These calipers 64FL, 64F
Brake oil having a predetermined brake pressure is supplied to R, 64RL, and 64RR via a brake hydraulic system 52.

That is, the brake hydraulic system 52 is connected to the brake pedal 50, and is connected to the booster 66 using a hydric booster for boosting the depression force of the brake pedal 50, and the booster 66. The tandem master cylinder 68 for pressurizing the brake oil is transmitted by the boosted pushing force. The master cylinder 68 has a total of four discharge ports 70FL, 70FL.
It has FR, 70RL, and 70RR. Further, the brake hydraulic system 52 includes four discharge ports 70FL, 70F.
R, 70RL, 70RR and caliper 64FL, 64F
R, 64RL, 64RR are connected to each other, and the brake oil from the master cylinder 68 is adjusted to a predetermined brake pressure, and the corresponding brake device 60FL, 60FR, 6 is used.
Brake oil pipes 72FL, 72FR, 72RL and 72RR for supplying 0RL and 60RR respectively are further provided.

The booster 66 described above includes a supply pipe 74.
The engine oil is supplied from the reservoir tank 78 via the supply pipe 74 to the booster 66 by driving the pump 80, and the excess brake oil is supplied to the return pipe 76 via the supply pipe 74. It is configured to be returned to the reservoir tank 78 via the.

On the other hand, the above-mentioned brake pressure adjusting mechanism 54
Is the brake oil pipe 72FL, 72FR, 72R
ABSs and automatic braking valve units 82FL, 82FR, 82RL, and 82RR installed in the L and 72RR, respectively.
(Anti-skid brake device) Valve unit 84F
L, 84FR, 84RL, 84RR, respectively, and the brake oil from the master cylinder 68 is automatically brake valve units 82FL, 82FR, 82RL, 82RR.
First, and then the ABS valve unit 84F
It is configured to be supplied to the brake devices 60FL, 60FR, 60RL, 60RR of the corresponding wheels 12FL, 12FR, 12RL, 12RR through L, 84FR, 84RL, 84RR.

The automatic braking valve units 82FL, 82FR, 82RL, 82RR and the ABS valve units 84FL, 84FR, 84RL, 84RR will be described below.
The configuration will be described in detail. The automatic braking valve units 82FL, 82FR, 82RL, 82RR have the same configuration, and the ABS valve units 84FL, 8FL.
Since the 4FR, 84RL, and 84RR are also configured in the same manner, in the following description, the automatic braking valve unit 82FL and the ABS valve unit 84FL corresponding to the left front wheel 12FL will be described as a representative, and other description will be omitted. To do.

As shown in FIG. 2, the automatic braking valve unit 82FL includes a master cylinder 68 and a brake device 60.
A shutter valve 86FL capable of cutting off the communication state of the brake oil pipe 72FL connecting to the FL, and an automatic braking valve unit 82FL and an ABS valve unit 84FL in the brake oil pipe 72FL so that one end of the shutter valve 86FL is bypassed. And a pressure-increasing bypass pipe 88FL connected to a portion between the pressure-increasing bypass pipe 88FL and the master cylinder 68, and an oil pressure of the brake oil supplied to the brake device 60FL. One end is connected to a portion of the pressure-increasing bypass pipe 88FL between the pressure-increasing valve 90FL for increasing and the shutter valve 86FL described above so as to bypass the shutter valve 86FL, and the other end is connected to the master valve. Decompression bypass connection connected to the cylinder 68 And 92FL, is interposed the vacuum bypass pipe 92FL, and a pressure reducing valve 94FL for lowering the oil pressure of the brake oil supplied to the brake device 60FL.

These three types of valves 86FL, 90F
Both L and 94FL are electromagnetic 2-port 2-position switching valves. Further, between the pressure increasing valve 90FL and the master cylinder 68 in the pressure increasing bypass pipe 88FL described above, a hydraulic pump 98FL driven by a motor 96FL is discharged to the master cylinder 68 side and from the hydraulic pump 98FL. An accumulator 100FL for storing the brake oil and holding it at a constant pressure is provided on the pressure increasing valve 90FL side.

Here, the shutter valve 86FL described above is used.
Is in the open position, the brake pressure acts on the corresponding brake device 60FL according to the depression force of the brake pedal 50, and the normal braking operation is executed. On the other hand, when the shutter valve 86FL is in the closed position, the brake pressure from the master cylinder 68 does not act on the corresponding brake device 60FL. In this state,
The pressure increasing valve 90FL is set to the open position, and the pressure reducing valve 94 is
By switching each of the FLs to the closed position, the brake pressure from the accumulator 100FL described above acts on the corresponding brake device 60FL, and the automatic braking operation is executed. Further, in this state, by switching the pressure increasing valve 90FL to the closed position and switching the pressure reducing valve 94FL to the open position, the brake oil is returned from the corresponding brake device 60FL and the braking force is weakened. ..

The above-mentioned three valves 86FL, 90F
The switching operation of L and 94FL is executed by actuators (not shown) connected to each, and these actuators are drive-controlled based on a control signal from an automatic braking control unit (CAB) 49. ..

On the other hand, the ABS valve unit 84 described above
FL is a shutter valve 102F including a 3-port 2-position switching valve provided in the brake oil pipe 72FL.
This shutter valve 102FL is connected to a traction control unit (CTR) 103, so that during braking (during normal braking by the driver depressing the brake pedal 50, and depression of the brake pedal 50). In this case, the shutter valve 102FL is appropriately controlled to be switched between the open position and the closed position during the automatic braking that is performed independently of each other), thereby adjusting the braking pressure applied to the corresponding brake device 60FL. , The corresponding wheels 12FL are not locked.

The ABS system configuration will not be described in detail because it is not directly related to the present invention, but in addition to the shutter valve 102FL described above, a motor-driven hydraulic pump 104FL and a pair of accumulators 106F are provided.
L, 108FL, etc. are provided. The above-mentioned traction control unit (CTR) 103 is also connected to the above-mentioned sub-throttle controller 48, and details thereof will be omitted. However, in order to adjust the engine generated torque during traction control, an overall control unit to be described later will be described. The opening / closing control of the sub-throttle valve 38 is performed via the (TCU) 113.

The traction control unit (C
The main throttle opening sensor 36, the sub-throttle opening sensor 40, and the vehicle speed sensor 42 described above are connected to the TR) 103, and the accelerator opening sensor 110 for detecting the depression amount of the accelerator pedal 46 is connected. When,
Wheel rotation speed sensors 112FL, 112 for detecting the rotation speeds of the wheels 12FL, 12FR, 12RL, 12RR.
FR, 112RL, 112RR (shown in FIG. 1) and a road surface μ sensor 114 for detecting the friction coefficient of the road surface are connected, and from these, a main throttle opening signal, a sub throttle opening signal, and a vehicle speed signal. , Accelerator opening signal, and each wheel 12FL, 12FR, 12RL, 12RR
The rotational speed signal and the road surface friction coefficient signal are input respectively. Then, the traction control unit (CTR) is provided with the wheels 12FL, 12FR, 12R.
The slip state of the wheel is detected based on the rotation speed signals of L and 12RR, and the predetermined traction is performed according to the main throttle opening signal, the sub throttle opening signal, the vehicle speed signal, the accelerator opening signal, and the road surface friction coefficient signal. It is designed to execute control.

Here, the traction control unit (CR
T) 103 input main throttle opening signal, sub throttle opening signal, vehicle speed signal, accelerator opening signal,
Rotational speed signals of the wheels 12FL, 12FR, 12RL, 12RR, road surface friction coefficient signals, etc. are transmitted to the overall control unit (TCU) 113, which will be described later, and are transmitted to the automatic braking control unit (CAB) 49 via this. It is designed to work.

The automatic transmission control unit (C
The AT) 33, the automatic braking control unit (CAB) 49, and the traction control unit (CTR) 103 are connected to the overall control unit (TCU) 113. It is designed to be appropriately adjusted and controlled. That is, the overall control unit (TCU) is connected to the injection valve controller 58, and drives the injection valve controller 58 so that the optimum fuel injection amount for the current operating state is injected from the fuel injection valve 56. It is designed to execute basic control operations for controlling. On the other hand, this total control unit (TCU)
In addition to executing this basic control operation, the automatic control unit 113 automatically detects when the automatic braking control unit (CAB) 49, which will be described in detail later, determines that the relative relationship with the front obstacle has fallen into a predetermined dangerous state. Braking control unit (CA
On the basis of a command (interruption activation signal) from B), the automatic braking control operation is interrupted to this basic control operation, and is also interrupted to the automatic transmission control operation of the automatic transmission control unit (CAT). It is configured like.

Here, the front obstacle refers to an object existing in front of the own vehicle, and is directed in the same lane as the lane in which the own vehicle is traveling (that is, toward the front). Not only a moving vehicle, but also a vehicle traveling in the same lane toward the vehicle, a vehicle stopped in the same lane, and an object other than the vehicle, and a vehicle traveling in front of the vehicle. In the meantime, for example, when another vehicle enters the driving lane of the own vehicle from the side road, the entered vehicle is updated so as to be recognized as a front obstacle for the own vehicle.

Next, referring to FIG. 3, a detection mechanism 11 for detecting the distance between the vehicle and the obstacle ahead and the relative speed of the two.
The configuration of No. 6 will be described. That is, the detection mechanism 116 includes the ultrasonic radar unit 118 provided on the front part of the vehicle body. Although not shown in detail, the ultrasonic radar unit 118, as is well known, transmits ultrasonic waves from an ultrasonic wave transmission unit to a front obstacle such as a vehicle located in front of the own vehicle, and The ultrasonic receiving unit is configured to receive the reflected ultrasonic waves reflected by the front obstacle. An arithmetic unit 120 is connected to the ultrasonic radar unit 118. This arithmetic unit 12
The value 0 indicates the distance between the own vehicle and the forward obstacle and the relative distance between the two based on the delay time (Doppler shift) from the transmission time point of the ultrasonic radar reception wave in response to the detection result from the ultrasonic radar unit 118. It is configured to calculate speed.

On the other hand, the above-mentioned detection mechanism 116 is provided with a pair of laser radar units 122 and 124 provided on the left and right of the front portion of the vehicle body. Each of the laser radar units 122 and 124 emits a pulsed laser beam having a predetermined wavelength from the laser emitting section and receives a reflected laser beam reflected by the above-mentioned front obstacle at the laser beam receiving section. It is configured. Each of the laser radar units 122 and 124 is connected to the above-described arithmetic unit 120 via a signal processing unit 126, and this arithmetic unit 120 is based on the delay time from the transmission point of the received laser light and the vehicle ahead. It is configured to calculate the distance to the obstacle and the relative speed between the two.

Here, the arithmetic unit 120 basically uses the calculation results of the distance and the relative speed by the system of the pair of laser radar units 122 and 124, and the distance to the front obstacle is a predetermined distance or less ( (For example, about 10 m or less), or when traveling accuracy under bad weather conditions such as fog and the detection accuracy is not guaranteed due to scattering of the emitted laser light, the distance by the system of the ultrasonic radar unit 118 And, the calculation result of the relative speed is used.

Each of the laser radar units 122,
Reference numeral 124 is provided to be able to change the emission directions of the respective laser lights in a state in which they are synchronized with each other in a horizontal plane, and a drive motor 128 is attached in order to move and drive the laser radar units 122 and 124 in the horizontal plane. ing. The arithmetic unit 120 described above is connected to the drive motor 128, and the operation of the drive motor 128 is executed by the arithmetic unit 120. On the other hand, the drive motor 128 is provided with an angle sensor 130 for detecting the drive rotation angle. The angle sensor 130 is connected to the arithmetic unit 120. The arithmetic unit 120 is provided with the angle sensor 13
Based on the detection results from 0, each laser radar unit 1
The transmitting / receiving direction of the laser light at 22, 124 can be detected. That is, the arithmetic unit 1
In the calculation of the distance and the relative speed in the system of the laser radar units 122 and 124 by 20, the transmission / reception direction of the pulse laser light is taken into consideration.

This arithmetic unit 120 is connected to the above-mentioned automatic braking control unit (CAB) 49, where
The distance information between the own vehicle and the front obstacle as a result of the calculation and the relative speed information of the both are output. The automatic braking control unit (CAB) 49 is, as described above with reference to FIG. 1, the brake pressure adjusting mechanism 54, specifically, the automatic braking provided corresponding to each wheel 12FL, 12FR, 12RL, 12RR. Valve unit 82FL,
82FR, 82RL, 82RR and the sub-throttle valve controller 48, the injection valve controller 58, and the automatic transmission control unit (CAT) through the overall control unit (TCU) 113, and the above-described calculation is performed. Based on the result, the automatic braking control operation is executed according to the control procedure described later.

The automatic braking control unit (CAB) 49
As shown in FIG. 3, the relative relationship between the front obstacle and the distance display panel 132 that displays the distance information between the own vehicle and the front obstacle at the input location is dangerous. Alarm buzzer 13 that gives an alarm when it is judged to be in a state
3 is connected, and these separation distance display panels 13
Both 2 and the alarm buzzer 134 are arranged in an alarm display unit 136 attached to an instrument panel (not shown) in the vehicle compartment. With these arrangements, the driver can recognize the distance between the front obstacle and the vehicle from the numerical value displayed on the separation distance display panel 132, and the driver can pay attention to the front obstacle. Even if not, the warning buzzer 133 sounds when the distance between the front obstacle and the own vehicle is judged to be a predetermined dangerous state, and the relation with the front obstacle is predetermined. You will be able to recognize that you are in a dangerous state.

Next, the control procedure of the automatic braking control operation in the automatic braking control unit (CAB) will be described with reference to FIGS. 4 to 10. First, as shown in FIG. 4, an automatic braking control operation for preventing contact with a front obstacle is started at a predetermined start timing. Here, in this embodiment, as is apparent from the above description, as the brake pressure adjusting mechanism 54 provided in the brake hydraulic system 52, the automatic braking valve units 82FL, 82FR for automatic braking,
82RL and 82RR are ABS valve units 84FL, 84FR, 84RL and 84RR for traction control.
In order to balance the operation of both of them, the automatic braking control operation is to be repeatedly activated at a cycle of, for example, 7 msec, in the same manner as the traction control operation. It is set.

That is, when the automatic braking control operation is started, first, in step S10, various input information reading operations necessary for executing the automatic braking operation are executed. As the input information, the arithmetic unit 120
In addition to including the distance information Lx between the front obstacle of the vehicle and the relative speed information Vx of the both calculated in step 1, the road surface μ sensor 11 via the overall control unit (TCU) 113.
4 includes road surface friction coefficient information μ, running range position information RI and shift gear position information GI from the automatic transmission control unit (CAT).

After that, in step S12, based on the various information read in step S10, various thresholds L ₀ , L ₀ ′, which are necessary for executing the automatic braking control operation,
Set L ₁ L ₁ , L ₂ and L ₂ ′. Here, all thresholds are expressed as distances, and in particular the threshold L ₀
Indicates that there is a possibility that the own vehicle may come into contact with an obstacle ahead, and a reference value for starting activation of the braking force based on the brake hydraulic system 52 in the automatic braking operation to prevent contact.
Further, the threshold value L ₀ ′ is a reference value for starting the activation of the braking force based on the engine braking during the automatic braking operation in order to prevent the contact of the host vehicle with the obstacle in front of the vehicle. ing. In this embodiment, the threshold value L ₀ ′ is defined based on the map shown in FIG. This map will be described in detail later. The threshold L ₀ is set to 80% of the threshold L ₀ ′ in this embodiment.

That is, in this embodiment, as will be described later, basically, the braking force by the engine brake is first activated, and then the braking force by the brake hydraulic system 52 is activated. . On the other hand, the threshold value L ₁ is set to the above-mentioned alarm buzzer 1 before the start of this automatic braking operation.
34, a value serving as a reference for starting the operation of issuing an alarm to the driver via 34. The threshold L ₁ is the threshold L
It is set to be a predetermined amount longer than ₀ '. That is, this threshold value L ₁ is used as a reference value for judging that the distance between the vehicle and the front obstacle is in a dangerous state when the automatic braking control is performed. In addition, the threshold L ₂ is set so that after the automatic braking operation is started, there is no possibility of contact with a front obstacle, and the brake hydraulic system 52.
The reference value when canceling the automatic braking operation by the above is shown, and the threshold value L ₂ ′ shows the reference value when canceling the automatic braking operation based on engine braking under the same conditions. Here, the threshold L ₂ is set to 80% of the threshold L ₂ ′ in this embodiment. That is, in this embodiment, as will be described later, basically, the braking force by the brake hydraulic system 52 is first released, and then the braking force by the engine brake is released. The thresholds L ₂ and L ₂ ′ are
The lengths are set to be respectively longer than the above-mentioned thresholds L ₀ and L ₀ ′ by a predetermined amount.

That is, in this embodiment, the thresholds are set to have a magnitude relation represented by the following inequality: L ₂ ′> L ₂ > L ₀ ′> L ₀ L ₁ > L ₀ ′.

Here, the procedure for determining the threshold L ₀ ′ will be described with reference to FIG. First, line A in FIG.
Indicates a first threshold line, and the first threshold line A is
Front obstacle serving vehicle, when the vehicle stops in contact with the front obstacle of the vehicle, shows the following distance required to prevent the vehicle is in contact with the vehicle, the relative speed V _x regardless of the size, always, when the front obstacle is a stationary object (i.e., the relative when the speed V _x is the same as the traveling speed V ₀ which the vehicle) the same next-in numeric expression V ₀ ^2/2 [mu] g Take a numerical value to represent. Further, the line B in FIG. 5 shows a second threshold line, and this second threshold line B is for preventing contact with a front obstacle vehicle when the vehicle is fully braked. Shows the required inter-vehicle distance, and the numerical formula V _x · (2V ₀ −
Take the value represented by V _x ) / 2 μg.

On the other hand, a line C in FIG. 5 shows a third threshold line, and this third threshold line C is obtained when the vehicle as an obstacle ahead is subjected to the slow braking of deceleration μ / 2g. The inter-vehicle distance required to prevent contact with this vehicle is shown.
Further, the line D in FIG. 5 represents the fourth threshold line,
The fourth threshold line D represents an inter-vehicle distance required to prevent contact with a vehicle ahead when the vehicle keeps a constant vehicle speed, and is represented by a numerical formula V _x / 2 μg. To take. Further, the line E in FIG. 5 indicates the threshold line of, and the threshold line E of this' cannot prevent the contact with the vehicle which is the front obstacle even if the own vehicle applies the automatic braking. It shows the inter-vehicle distance that can reduce the impact force to some extent. In this embodiment, it is assumed that the second threshold line B is selected via a mode changeover switch (not shown), and this second threshold line B is used to determine the threshold value corresponding to the relative speed V _x at the present time. L ₀ ′ is required.

As described above, after the various thresholds L ₀ , L ₀ ′, L ₁ L ₁ , L ₂ , and L ₂ ′ are set in step S12, in step S14, the own vehicle and the forward obstacle are detected. It is determined whether or not the relative speed V _x between them is 0 or more. Here, in this embodiment, the relative velocity V _x
Indicates a state where both are close to each other when it takes a positive value, and indicates a state where both are separated from each other when it takes a negative value. This step S
When it is determined to be YES in 14, that is, when it is determined that the relative speed V _x has a positive value and the two are in close proximity to each other, the automatic braking force activating routine is executed thereafter.

That is, in the following step S16,
It is determined whether the relationship between the vehicle and the front obstacle is in the first danger mode. Here, in this one embodiment, the first danger mode detects a change state of the distance between the own vehicle and the front obstacle, and as a result, changes to a continuously shortened direction. That is the case. In this case, it is determined that the target object to be the front obstacle remains the same and there is no change. It is determined that the degree is low. On the other hand, the second dangerous mode is a case where it is determined that the above-described change state of the distance between the own vehicle and the front obstacle is detected, and as a result, the change is discontinuously shortened. Is. In this case, it is judged that a vehicle, an object, or a person newly defined as a front obstacle has entered between the obstacle that was previously recognized as a front obstacle and the front obstacle. Is judged to be extremely close to the own vehicle, and it is determined that the degree of danger is extremely high.

If it is determined to be YES in step S16 described above, that is, if it is determined that the relationship between the front obstacle and the vehicle is the first dangerous mode with low risk, the process continues. In step S18, the first danger mode avoidance operation is executed. The first danger mode avoidance operation will be described in detail as a subroutine with reference to FIG. On the other hand, step S16 described above
When it is determined to be NO in step S20, that is, when it is determined that the relationship between the front obstacle and the vehicle is the second dangerous mode with high risk, the second risk avoiding operation is performed in step S20. Run. The second danger mode avoidance operation will be described in detail as a subroutine with reference to FIG.

Incidentally, step S16 or step S18
In executing the first or second danger mode avoiding operation in step 1, the operation of fixing the transmission gear position, the one-way (O
/ W) Clutch invalid operation and lockup (L /
U) The clutch engagement operation is executed, but if the transmission gear position is fixed, the one-way clutch is disabled, and the lockup clutch is engaged in this way, the engine speed decreases due to the deceleration operation. As a result, the engine may be in a so-called stalled state, and the engine brake may not be activated.

For this reason, step S18 or step S
When step 20 is executed, the process proceeds to step S22, where
It is determined whether the engine speed is at the engine limit. If YES is determined in this step S22, that is, if it is determined that the engine speed is at the engine stall limit, the fixing operation of the shift gear position is released in the subsequent step S24, and the one-way clutch is disabled in step S26. Release operation, and then step S
At 28, the engagement operation of the lockup clutch is released, and the engine is brought into a free state so that engine stalling does not occur. And after ending this control procedure,
Wait for the start of the next control procedure set after 7 msec.

On the other hand, in step S22 described above, N
When it is determined to be O, that is, when it is determined that the engine speed has not reached the engine stall limit, the shift gear position of the first or second dangerous mode avoiding operation in step S18 or step S20 is changed. Since it is determined that the engine is not in the stalled state even if the fixed operation, the one-way clutch invalid operation, and the lock-up clutch engaging operation are continuously executed, step S2 is performed.
4, without executing step S26 and step S28, the control procedure of this time is ended, and the activation of the next control procedure set after 7 msec is awaited. On the other hand, when it is determined NO in step S14 described above, that is, when the relative speed V _x is determined to be a negative value and it is determined that the front obstacle is gradually moving away from the vehicle, the control is performed. The automatic power release routine is executed.

That is, first, in step S30, it is determined whether or not the separation distance L _x is larger than the threshold value L ₂ . If NO is determined in this step S30, that is, the separation distance L _x is within the range defined by the inequality L _x ≦ L ₂ , the relation with the front obstacle is still in a dangerous state, and the automatic braking control is performed. If it is determined that the operation needs to be continued, the control procedure of this time is ended without specifically executing the automatic release routine of the braking force,
Wait for the start of the next control procedure set after 7 msec. That is, even when it is determined to be NO in step S30, step S22 or step S2 is performed in advance.
In 6, when the engine automatic braking control is activated, or when the brake automatic braking control is activated,
These will continue to be executed.

In step S30 described above, Y
When it is judged as ES, that is, the separation distance L _x is the inequality L
Within the range defined by _x > L ₂ , the brake hydraulic system 5
When it is determined that the braking force by 2 is unnecessary, the process proceeds to step S32, where a brake automatic braking control release signal is output to cancel the brake automatic braking control operation in the brake hydraulic system 52. After that, the process proceeds to step S34, where the flag F indicating that the automatic brake control operation is being performed is reset to "0",
Brake Indicates that the automatic braking control operation has been released.
Then, in step S36, it is determined whether or not the separation distance L _x is larger than the threshold value L ₂ ′. If NO is determined in this step S36, that is, the separation distance L _x is within the range defined by the inequality L ₂ <L _x ≦ L ₂ ′, and the relationship with the front obstacle is still in a dangerous state. However, if it is determined that the engine automatic braking control operation needs to be continued although the strong braking force by the brake hydraulic system 52 is unnecessary, the control procedure of this time is ended and set after 7 msec. Wait for the next control procedure to be started.

On the other hand, in step S36 described above, Y
When it is judged as ES, that is, the separation distance L _x is the inequality L
If it is judged that the braking force by the engine brake is unnecessary, it is within the range defined by _x > L ₂ ′,
In step S38, an engine automatic braking control release signal is output to the overall control unit (TCU) 113 to release the engine automatic braking control operation. Upon receiving the engine automatic braking control release signal, the overall control unit (TCU) 113 stops the closing operation of the sub throttle valve 38 via the sub throttle valve controller 48 and restores it to the fully open state. After that, the process proceeds to step S40, an alarm operation canceling signal for canceling the alarm operation is output, that is, the ringing operation in the alarm buzzer 134 is stopped, and a series of control procedures is completed, and 7 msec.
It waits for the start of the next control procedure set later. In this way, the series of procedures of the automatic braking control operation is completed.

Next, referring to FIG. 6, the control procedure for the first danger mode avoiding operation in step S18, that is, the risk avoiding operation when it is determined that the risk is small, will be described in detail as a subroutine. explain. Step S1
8 is activated, first, in step S18A,
It is determined whether or not the distance (hereinafter, simply referred to as a separation distance) L _x between the vehicle and the front obstacle is smaller than the threshold value L ₁ described above. If NO is determined in step S18A, that is, the separation distance L _x is within the range defined by the inequality L _x ≧ L ₁ , and the area that defines the dangerous state has not yet been reached, the alarm buzzer 134 is activated. When it is determined that the ringing does not need to be performed, the automatic braking control operation does not have to be executed, so the control procedure of this time is ended without executing the braking force automatic activation routine specifically, and after 7 msec. Wait for the next control procedure to start.

On the other hand, in this step S18A, YE
If it is determined that S, that is, the separation distance is the inequality L _x <L
When it is determined that the vehicle is in the range defined by ₁ and the dangerous state is reached, the process proceeds to step S18B, the alarm buzzer 134 is sounded, and the driver is separated from the front obstacle by a distance L.
_Notify that _x is in danger. Then, in step S18C, it is determined whether the separation distance L _x is smaller than the threshold value L ₀ ′. When NO is determined in this step S18C, that is, the separation distance L _x is the inequality L
_When it is determined that the alarm operation is continued but the automatic braking operation is not executed within the range defined by ₀ ′ ≦ L _x <L ₁ , the current control procedure is performed. And waits for the start of the next control procedure set 7 msec later.

Here, YES in step S18C.
In other words, if the separation distance L _x is inequality L _x <
If it is within the range defined by L ₀ ′ and it is determined that the automatic braking operation needs to be executed, step S18
Proceeding to D, an engine brake is generated in the engine 14 and an interrupt activation signal is output to the overall control unit (TCU) 113 in order to activate the braking force by this engine brake. Start engine automatic braking control.
The control procedure of this engine automatic braking control will be described later in FIG.
Will be described in detail with reference to.

After activating the second engine automatic braking control in step S18D, the subsequent step S18
At 18E, it is determined whether the separation distance L _x is smaller than the threshold L ₀ . In this step S18E, N
If it is judged to be O, that is, the separation distance L _x is inequality L ₀
If it is determined that the braking force is within the range defined by ≦ L _x <L ₀ ′ and only the braking force by the engine brake is applied as the risk avoidance operation, the control procedure of this time is performed. After completion, wait for the start of the next control procedure set 7 msec later.

On the other hand, when YES is determined in step S18E described above, that is, the separation distance L _x is within the range defined by the inequality L _x <L ₀ , it is determined that a strong braking force is required. In this case, the process proceeds to step S18F to activate the brake automatic braking control operation by the brake hydraulic system 52 defined as the interrupt routine.
The control procedure of this automatic braking operation will be described later in detail. Then, in step S18G, a flag F indicating that the brake automatic braking control operation is being executed.
Is set to "1" and waits for the next control procedure start set after 7 msec.

The automatic brake control operation in step S18F is executed as an interrupt routine independent of the main routine, and once activated, the control operation is executed unless the corresponding release operation is executed. It is set to continue. When the execution of step S18G is completed in this way, the execution of all control procedures in this subroutine is completed, and the process returns to the original main routine.

Next, with reference to FIG. 7, the control procedure of the first engine automatic braking control operation in step S18D described above will be described as an interrupt routine in the overall control unit (TCU) 113. First, step S1
When the first engine automatic braking control operation is started in 8D, it is determined in step S42 whether or not "1" is set to the flag F indicating that the brake automatic braking control is activated. If it is determined NO in step S42, that is, if it is determined that the brake automatic braking control is not activated in advance,
A control procedure for setting the engine brake control amount EBC (which will be described in detail later) according to the current traveling range position or the transmission gear position is executed.

That is, in the following step S44,
The travel range position currently set in the automatic transmission 16 is determined based on the travel range position information RI previously read in step S10 in the main routine described above. In this step S44, the automatic transmission 1
6, the currently set travel range position is "L"
When the shift gear position is determined to be fixed to the 1st speed, the engine brake control amount EBC is set to the minimum value (MIN) in step S46. Then, in the subsequent step S48, since the degree of risk is low, the lockup clutch is gently engaged. By gently engaging the lockup clutch in this way, it is possible to effectively suppress the shock that occurs during lockup, and as a result, it is possible to suppress the deceleration shock to the driver as much as possible. is there.

On the other hand, in the following step S50, the sub-throttle valve 38 is closed and driven via the sub-throttle valve controller 48 with the minimum engine brake control amount EBC set in the above-mentioned step S46. Here, by setting the minimum engine brake control amount EBC, the sub throttle valve controller 48
Drives the sub-throttle valve 38 so that the intake passage 44 is closed at a slow closing speed, in other words, the engine brake is gradually activated.

On the other hand, in step S44 described above,
When it is determined that the currently set running range position in the automatic transmission 16 is "S" (that is, the transmission gear position is set to the 1st speed or the 2nd speed), the engine brake control amount is determined in step S52. EBC is set to the intermediate value (ME
Set to D). Then, the process proceeds to step S48 described above, and the lock-up clutch is gently engaged. Then, in step S50, the sub-throttle valve controller 48 is operated with the intermediate engine brake control amount EBC set in step S52. Valve 3
8 is closed and driven. Here, when the engine brake control amount EBC of the intermediate value is set, the sub throttle valve controller 48 drives the sub throttle valve 38 so that the intake passage 44 is closed at the normal (medium) closing speed.

Further, in step S44 described above,
If it is determined that the traveling range position currently set in the automatic transmission 16 is "D" (that is, the transmission gear position is set to an arbitrary position optimal for the traveling state), in step S54, the automatic transmission is automatically performed. In order to prohibit the upshift operation in the transmission 16, in other words, in order to keep the current transmission gear position constant, the transmission gear position is gently fixed. By gently fixing the shift gear position in this way, the shock due to this fixing operation is alleviated, and the driver does not feel the shock, and therefore does not feel the discomfort associated with the fixing operation and is in a very natural state. The driving operation can be continued with.

Then, in step S56, the one-way clutch (not shown) in the automatic transmission 16 is disabled (fixed). That is, when the intake passage 44 is closed in the drive range "D", the vehicle normally enters the inertial traveling state due to the action of the one-way clutch. In this inertial traveling state, the driver feels uneasy as if he / she was pulled forward. However, by fixing the one-way clutch in step S56, it is possible to eliminate the anxiety that the driver feels pulled forward.

Then, in the following step S58, it is determined where the current transmission gear position is based on the transmission gear position information GI read in advance in step S10. That is, when it is determined in step S58 that the transmission gear position is set to "first speed", the process proceeds to step S46 described above, the engine brake control amount EBC is set to the minimum value (MIN), and the step In S48 and S50, the sub-throttle valve 38 is gently closed and driven with the minimum engine brake control amount EBC. On the other hand, in step S58,
When it is determined that the shift gear position is set to the "second speed", the process proceeds to step S52 described above, the engine brake control amount EBC is set to an intermediate value (MED), and the process proceeds to steps S48 and S50. Then, the sub-throttle valve 38 is closed and driven at the normal closing speed with the intermediate engine brake control amount EBC.

On the other hand, if it is determined in step S58 that the transmission gear position is set to "third speed" or "fourth speed" (including overtop), engine brake control is performed in step S60. The amount EBC is set to the maximum value (MAX), and thereafter, the process proceeds to step S48 and step S50, and the sub-throttle valve 38 is rapidly closed and driven with this maximum engine brake control amount EBC. By rapidly closing and driving the sub-throttle valve 38 in this way, a powerful engine brake is activated.

As described above, when the operation of closing the sub-throttle valve 38 with the predetermined engine brake control amount EBC is executed in step S50, the intake passage 44 is fully closed by the sub-throttle valve 38 in subsequent step S62. It is determined whether or not the state has been reached. When NO is determined in this step S62, that is,
When it is determined that the intake passage 44 has not been fully closed by the sub-throttle valve 38, the process returns to step S60 described above, and the closing operation of the sub-throttle valve 38 is continued to become the fully closed state. Wait for On the other hand, step S
If YES is determined in 62, that is, if it is confirmed that the intake passage 44 is fully closed by the sub-throttle valve 38, in the subsequent step S64, the fuel injection valve 56 is released from the fuel injection valve 56 via the injection valve controller 58. Cut off fuel injection.

Thereafter, in the subsequent step S66, it is determined whether or not the engine automatic braking control release signal is output. If it is determined NO in step S66, that is, if it is determined that the engine automatic braking control release signal is not output without executing step S38 described above, step S42 described above.
Then, the automatic engine braking control is started again. On the other hand, if YES is determined in this step S66, that is, if it is determined that the engine automatic braking control cancellation signal is output in the above-mentioned step S38, this engine automatic braking control operation is ended, and a series of these The control procedure of the automatic engine braking control ends.

If YES is determined in the above step S42, that is, the flag F is "1".
Is set and it is determined that the automatic brake control is activated, the engine brake control amount EB
Perform a control procedure to set C to the maximum value. That is, if YES is determined in step S42, the process immediately jumps to step S68, the shift gear position is immediately fixed, the one-way clutch is invalidated in subsequent step S70, and the engine brake control amount EBC is set to the maximum value (step S72). MAX), and in step S74, with the maximum engine brake control amount EBC,
The sub-throttle valve 38 regardless of the gear position
The valve is suddenly closed to drive the engine brake strongly. Then, in step S76, the lockup clutch is immediately engaged.

That is, steps S68 to S76.
By executing the powerful engine brake at the same time as the automatic braking control of the brakes, immediately fixing the shift gear position, disabling the one-way clutch, and immediately engaging the lock-up clutch, the overall performance is extremely high. The vehicle is decelerated with a strong braking force so that a reliable danger avoidance operation can be achieved with a short stop distance. On the other hand, in the state where the flag F is set to "1" and the automatic brake control operation has already been executed in this manner, after executing the above step S76,
The process directly proceeds to step S64, where the fuel cut operation is executed. That is, in a state in which the automatic brake control operation is not yet executed, step S <b> 62 and step S <b> 64 are executed to wait until the intake passage 44 is fully closed by the sub throttle valve 38. Although it was set to execute the cut operation, the brake automatic braking control operation has already been executed and a stronger braking force is required, so that it is not necessary to wait until the intake passage 44 is fully closed. Even if the intake passage 44 is being closed, the fuel supply cut operation is executed,
It is designed so that the braking force is exerted immediately.

In this way, in the first automatic engine braking control procedure in the first dangerous mode avoidance control for avoiding the first dangerous mode in which the degree of risk is judged to be low, the automatic brake automatic braking control is still performed. In a state where the operation is not activated, the engine brake is exerted in a state where the deceleration shock is suppressed as much as possible by the engine brake control amount EBC substantially corresponding to the shift gear position.
By gently executing the fixing operation of the shift gear position and the engaging operation of the lockup clutch, it is considered that the shock at that time is not transmitted to the driver.

On the other hand, when the automatic braking control operation has already been started, it is necessary to stop the vehicle urgently and avoid the danger rather than taking into consideration not to give a deceleration shock to the driver. Therefore, regardless of the gear position, the intake passage 44 is closed with the maximum engine brake control amount EBC, and the fuel supply is cut simultaneously with this closing operation.
In addition to urgently activating the engine brake, immediately fix the transmission gear position, disable the one-way clutch,
Moreover, by immediately engaging the lock-up clutch, the engine brake can be immediately exerted. In this way, engine braking can be activated according to the situation.

Next, with reference to FIG. 8, the control procedure for the second danger mode avoiding operation in step S20 described above, that is, the risk avoiding when it is determined that the degree of danger is high, will be described in detail as a subroutine. explain. First, when step S20 is started, in step S20A,
The alarm buzzer 134 is activated to notify the driver that the obstacle ahead is in a dangerous state with a high degree of danger. After that, in step S20B, in order to generate the engine brake in the engine 14 and activate the braking force by the engine brake, the overall control unit (TC
U) 113, an interrupt activation signal is output to activate the second engine automatic braking control operation defined as an interrupt routine. The control procedure of the second engine automatic braking control will be described later in detail with reference to FIG.

Next, in the subsequent step S20C, the automatic brake control operation by the brake hydraulic system 52, which is defined as an interrupt routine, is activated in order to activate the strong motive power. Incidentally, this step S2
The brake automatic braking control operation at 0C is the same as the brake automatic braking control operation at step S18F described above, and thus the description thereof is omitted here. Then, in step S20D, the flag F indicating that the brake automatic braking control operation is being executed is set to "1", and the process returns to the main routine.

In other words, in the second danger mode avoidance control operation, the driver's feeling of deceleration is completely abandoned, and the vehicle is surely stopped at a short stop distance in order to avoid the possibility of contact without fail. A powerful braking control operation is performed to cause the braking.
Specifically, the second danger mode avoidance control operation is configured so that the second engine automatic control and the brake automatic braking control are executed substantially simultaneously.

Next, referring to FIG. 9, step S20B
The control procedure of the second automatic engine braking control operation executed in step 1 will be described as an interrupt routine in the overall control unit (TCU) 113. That is, step S
When the second engine automatic braking control operation is started in 20B, the shift gear position is immediately fixed in step S78, the one-way clutch is disabled in subsequent step S80, and the engine brake control amount EBC is set to the maximum value in step S82. Set to (MAX),
In step S84, the sub-throttle valve 38 is abruptly closed and driven by the maximum engine brake control amount EBC regardless of the transmission gear position, and the engine brake is strongly activated. Then, in step S86, the lockup clutch is immediately engaged. Then, in step S88, the fuel supply cut is executed.

That is, steps S78 to S88.
By executing the powerful engine brake at the same time as the automatic braking control of the brakes, immediately fixing the shift gear position, disabling the one-way clutch, and immediately engaging the lock-up clutch, the overall performance is extremely high. The vehicle is decelerated with a strong braking force so that a reliable danger avoidance operation can be achieved with a short stop distance.

In this way, in the second automatic engine braking control procedure in the second danger mode avoidance control for avoiding the second danger mode which is judged to have a high degree of danger, the driver is given a deceleration shock. Than consider not giving
Since it is necessary to stop the vehicle urgently and effectively avoid the danger, the intake passage 44 is closed with the maximum engine brake control amount EBC regardless of the gear position, and fuel is supplied simultaneously with this closing operation. By executing a cut and urgently activating the engine brake, immediately fixing the transmission gear position, disabling the one-way clutch, and immediately engaging the lockup clutch, the engine brake is immediately exhibited. Achieving a profitable state.

In this way, the braking force can be activated according to the degree of danger that has occurred. In other words, according to this embodiment, when the degree of danger that has occurred is small, deceleration is suppressed to such an extent that the deceleration operation for avoiding danger does not make the driver feel uncomfortable, and a good running state is achieved. On the other hand, when the degree of danger that has occurred is large, the driver feels the discomfort felt and ignores the discomfort felt by the driver. You will be able to stop your vehicle.

Next, referring to FIG. 10, step S18
The control procedure of the brake automatic braking control operation in F will be described as an interrupt routine in the automatic braking control unit (CAB). First, in the state before the brake automatic braking control operation is executed, the brake pressure adjusting mechanism 5
4 automatic braking valve unit 82FL, 82F
Shutter valve 86F for each of R, 82RL, and 82RR
L, 86FR, 86RL, 86RR are all in the open state, and pressure increasing valves 90FL, 90FR, 90R
L, 90RR and pressure reducing valve 94FL, 94FR, 94R
Both L and 94RR are in a closed state. In this way, the brake pressure generated in the master cylinder 68 by depressing the brake pedal 50 is applied to the wheels 12FL, 12FL.
The FR, 12RL, and 12RR are acted on respectively so that the manual braking operation can be executed.

When the brake automatic braking control operation is started in step S18F from the state before the execution of the brake automatic braking control operation as described above, in step S92, the automatic braking valve unit 82FL in the brake pressure adjusting mechanism 54, 82FR, 82RL, 82RR shutter valves 86FL, 86FR, 86RL,
The 86RR is closed and driven. Thereby, the brake pressure due to the depression of the brake pedal 50 is applied to each wheel 12FL,
Brake device 60F of 12FR, 12RL, 12RR
L, 60FR, 60RL, 60RR cannot be acted on, in other words, the brake automatic braking control operation is enabled thereby.

Thereafter, in step S94, it is determined whether or not the brake pressure acting on the brake devices 60FL, 60FR, 60RL, 60RR of the wheels 12FL, 12FR, 12RL, 12RR has reached a predetermined pressure.
If NO is determined in this step S94, that is, the braking devices 60FL, 60FR, 60R are currently being used.
When it is determined that the brake pressure acting on L, 60RR is insufficient, the pressure increasing valves 90FL, 90FR, 90RL, 90RR are driven to open in step S96, and the pressure reducing valve 9 is subsequently operated in step S98.
4FL, 94FR, 94RL, and 94RR are closed and driven. As a result, accumulators 100FR, 100F
The brake pressure accumulated in R, 100RL, 100RR is applied to each wheel 12FL, 12FR, 12RL, 12RR.
Brake devices 60FL, 60FR, 60RL, 60R
A predetermined braking operation is executed by acting on R.

On the other hand, in step S94 described above, Y
When judged as ES, that is, at present, the braking device 60
If it is determined that the brake pressure acting on FL, 60FR, 60RL, 60RR is sufficient, step S1
00, pressure increase valves 90FL, 90FR, 90R
L and 90RR are driven to be closed, and subsequent step S10
2, pressure reducing valves 94FL, 94FR, 94R
L and 94RR are driven open. As a result, accumulators 100FR, 100FR, 100RL, 100RR
The brake pressure stored in the
60FR, 60RL, 60RR does not work, and on the contrary, brake devices 60FL, 60FR, 60RL, 60
The brake pressure of RR is the pressure reducing valve 94FL, 94FR, 9
It will be reduced through 4RL and 94RR.

By repeating such a control procedure, the brake pressure acting on the brake devices 60FL, 60FR, 60RL, 60RR of the wheels 12FL, 12FR, 12RL, 12RR is set to a predetermined value regardless of the depression of the brake pedal 50. The value will be held constant.

On the other hand, when the above-mentioned step S98 or step S102 is executed, the routine proceeds to step S104, where it is judged whether or not the brake automatic braking control release signal is output. If NO is determined in this step S104, that is, if it is determined that the brake automatic braking control cancellation signal is not output without executing step S32 in the main routine shown in FIG. 4 described above, Then, the process returns to step S94, and the automatic brake braking control is started again from here.
On the other hand, if YES is determined in step S104, that is, if it is determined that the brake automatic braking control release signal is output in step S32 described above, the brake automatic braking control operation is terminated, and the series of these brakes is terminated. The control procedure of the automatic brake control is ended.

As described above in detail, in this embodiment, the automatic braking control is started when it is determined that the relationship between the vehicle and the front obstacle has entered a dangerous state. However, in this automatic braking control operation, first, the risk level in a dangerous state is determined, and when it is determined that this risk level is low (first dangerous mode), the first dangerous mode avoidance operation is executed. To be done. Specifically, in this first danger mode avoidance operation, an alarm operation is activated to notify the driver that a dangerous state has been reached between the driver and the front obstacle, and despite this notification operation, When the degree of danger to the front obstacle increases, first, the first engine automatic braking control procedure is executed to activate the engine brake,
When the speed of the vehicle is reduced and the risk of a front obstacle is further increased due to the activation of this engine brake, and the risk of a collision increases, automatic braking is performed to activate the braking force by the braking device. An operation of executing the control procedure to apply full braking to reduce the speed of the vehicle to a state where the vehicle is substantially stopped is executed.

Here, in the first engine automatic braking control in the first danger mode avoiding operation as described above,
Unless the brake automatic braking control is executed, the intake passage 44 is closed at the closing speed of the sub-throttle valve 38 that is substantially set according to the transmission gear position, and the transmission gear position is gently fixed, and It is set so that the lock-up clutch is gently engaged. Further, the fuel supply is cut off after the intake passage 44 is completely closed (fully closed). In this way, the deceleration operation for avoiding danger is performed gently, the deceleration feeling felt by the driver is set small, and the deceleration operation is automatically performed even if the driver does not press the brake pedal. It is designed to reduce the feeling of strangeness with respect to the deceleration operation.

In the first danger mode avoidance operation, even if such a gentle deceleration operation is automatically executed, if the danger state increases and the danger level increases, the automatic brake operation is performed. It is set so that the braking control operation is activated to exert a strong braking force via the braking device 60 to suddenly stop the vehicle. Here, when the brake automatic braking control operation is activated in this way, the content of the engine automatic braking control operation is changed in order to reliably activate a strong braking force. In any case, the sub-throttle valve 3 has the maximum closing speed.
8 is closed and the intake passage 44 is immediately closed. Even before the intake passage 44 is fully closed, the fuel supply is immediately cut off, and the speed change gear position is immediately changed. It is fixed and modified to operate so that the lockup clutch is immediately engaged. By the first engine automatic braking control operation changed in this way, a strong braking force can be reliably exerted even when the degree of danger increases in the first danger mode avoidance state.

On the other hand, in the automatic braking control operation, when the danger level in the dangerous state is judged to be high (second danger mode) as a result, the second danger mode avoidance operation is performed. Is executed. Specifically, in this second danger mode avoidance operation, an alarm operation is activated to inform the driver that a dangerous condition has been reached between the driver and a front obstacle, and at the same time, the engine brake is strongly activated. The second automatic engine braking control procedure is executed in order to activate the vehicle, and at the same time, the automatic braking control procedure is executed in order to activate the braking force by the braking device, and full braking is performed to substantially reduce the speed of the vehicle. The operation of lowering to a state where it is stopped is executed. That is, in the second danger mode avoidance operation, the alarm operation, the engine braking force activating operation, and the braking force activating operation by the braking device are executed substantially at the same time.

This second engine automatic braking control procedure is different from the first engine automatic braking control procedure when the degree of danger is low (in other words, the degree of danger in the first engine automatic braking control procedure). In order to reliably activate a strong braking force, the sub-throttle valve 38 is driven to be closed at the maximum closing speed regardless of the gear position, and the intake passage 44 is immediately closed. In addition, even before the intake passage 44 is fully closed, the fuel supply is immediately cut off, the shift gear position is immediately fixed, and the lockup clutch is immediately engaged. To work. In this way, strong engine braking force is immediately activated, and together with the braking force in the braking device that is activated at the same time,
Powerful means that the braking force (full braking) acts on the own vehicle, and it becomes possible to stop the own vehicle at a short stop distance, so that it is possible to reliably deal with a dangerous situation that suddenly occurs and has a high degree of danger. It is possible to stop the car urgently.

Needless to say, the present invention is not limited to the configuration of the above-described embodiment and can be variously modified without departing from the scope of the present invention. For example, in the above-described embodiment, the vehicle A is described as including the automatic transmission 16, but the present invention is not limited to such a configuration and is also applicable to a vehicle including a manual transmission. Is what you can do.

Further, in the above-described embodiment, the traveling range position and the transmission gear position information are output from the automatic transmission control unit (CAT) 33 to the automatic transmission 16 as the traveling range position information RI and the transmission gear position information GI. However, the present invention is not limited to such a configuration and uses a detection unit that detects a traveling range position and a transmission gear position that are actually set in the automatic transmission 16. Then, based on the detection result of the detection means, the automatic transmission 16 may be configured to recognize the traveling range position and the transmission gear position currently set.

Further, in the above-described embodiment, various thresholds are set to have a relationship represented by an inequality, but the present invention is not limited to such a relationship, and various thresholds are set. It is defined by the aspect. For example, in the above-described embodiment, the threshold L ₂ is larger than the threshold L ₀ (L ₂ > L ₀ ), and the threshold L ₂ ′ is larger than the threshold L ₀ ′ (L ₂ ′> L ₀ ′). However, the threshold L ₂ may be equal to or less than the threshold L ₀ (L ₂ ≦ L ₀ ), and the threshold L ₂ ′ may be the threshold L ₀ ′. The following may be satisfied (L ₂ ′ ≦ L ₀ ′).

Further, in the above-described embodiment, in order to reduce the engine output and generate the engine brake, the intake passage 44 is closed and the fuel injection valve 56 is driven.
Although it has been described that the fuel supply to the engine 14 is cut by driving and controlling the injection valve driver 58 connected to the above, the present invention is not limited to such a configuration, and only one of them is executed. By doing so, the engine output may be reduced to activate the engine brake, or the fuel supply may be reduced rather than being cut off. Is also good.

[0100]

As described above in detail, the automatic braking system for a vehicle according to the present invention detects the distance between the host vehicle and the obstacle and the relative speed, and the detecting means. A contact possibility determining means for determining whether or not the own vehicle may come into contact with the obstacle from the distance and relative speed between the own vehicle and the obstacle, and there is a possibility of contact by this determining means When it is determined that the degree is low, the first risk avoidance means for automatically controlling the engine to generate engine braking and then controlling the brake hydraulic system as necessary to exert the braking force. When the determination means determines that there is a high risk of contact, the engine is automatically controlled to generate engine braking, and the brake hydraulic system is controlled to exert braking force. First And a second danger avoiding means for controlling the engine with a first engine control content, and a second risk avoiding means different from the first engine control content. The feature is that the engine is controlled by the engine control contents of 2.

Further, in the automatic braking device for a vehicle according to the present invention, the first engine control content is that the intake passage is first closed and driven, and after the intake passage is fully closed, the fuel supply is cut off. The second engine control content is set so that the intake passage is closed and the fuel supply is cut off.

Further, in the automatic braking device for a vehicle according to the present invention, the own vehicle is provided with an automatic transmission, and the first danger avoiding means controls the automatic transmission according to the contents of the first automatic transmission control. However, the second danger avoiding means controls the automatic transmission with a second automatic shift control content different from the first automatic shift control content.

Also, in the vehicle automatic braking apparatus according to the present invention, the automatic transmission includes a lock-up clutch,
The content of the first automatic shift control is set so that the lock-up clutch is gently engaged, and
The content of the automatic shift control is set so that the lockup clutch is immediately engaged.

Further, in the automatic braking device for a vehicle according to the present invention, the automatic transmission is constructed such that the shift gear position can be fixed, and the content of the first automatic shift control is that the shift gear position is gently fixed. The second automatic transmission control content is set so as to immediately fix the transmission gear position.

Further, in the automatic braking device for a vehicle according to the present invention, when the judging means judges that the distance between the own vehicle and the front obstacle is continuously decreasing. In addition, when it is determined that the risk is low and the distance between the vehicle and the front obstacle is discontinuously shortened, it is determined that the dangerous motion is high. It is characterized by being configured.

Therefore, according to the present invention, even when it is determined that the own vehicle may come into contact with the front obstacle, the degree of risk is determined, and when the degree of risk is small, a gentle deceleration operation is performed. When the degree of danger is high, a rapid deceleration operation is executed to provide an automatic braking device for a vehicle that does not give the driver a feeling of strangeness.

[Brief description of drawings]

FIG. 1 is a system configuration diagram schematically showing the configuration of an embodiment of an automatic braking device for a vehicle according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a configuration of a brake hydraulic system applied to an automatic braking device.

FIG. 3 is a block diagram showing a configuration of a detection mechanism for detecting a distance between a vehicle and a front obstacle and a relative speed between the two.

FIG. 4 is a flowchart showing an overall control procedure of an automatic braking control operation in the automatic braking control unit.

FIG. 5 is a diagram showing a threshold setting map used in an automatic braking control operation.

FIG. 6 is a flowchart showing a control procedure of a first danger mode avoidance control operation.

FIG. 7 is a flowchart showing a control procedure of a first engine automatic braking control operation in the first danger mode avoidance control operation.

FIG. 8 is a flowchart showing a control procedure of a second danger mode avoidance control operation.

FIG. 9 is a flowchart showing a control procedure of a second engine automatic braking control operation in the second danger mode avoidance control operation.

FIG. 10 is a flowchart showing a control procedure of a brake automatic braking control operation.

[Explanation of symbols]

 A vehicle 10 automatic braking device 33 automatic transmission control unit 38 sub-throttle valve 48 sub-throttle valve controller 49 automatic braking control unit 54 brake pressure adjusting mechanism 56 fuel injection valve, 60 braking device 72 brake piping, 82 automatic braking valve unit 84 ABS The valve unit 113 is an overall control unit, and 116 is a detection mechanism.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location F02D 43/00 H 7536-3G 45/00 312 M 7536-3G 374 Z 7536-3G F16H 61/14 8917-3J A 8917-3J

Claims (6)

[Claims] 1. A detection means for detecting a distance and a relative speed between the own vehicle and an obstacle, and a distance and a relative speed between the own vehicle and the obstacle detected by the detection means. If there is a possibility of contact with the contact possibility judging means for judging whether there is a possibility of contact with an obstacle and the risk is low, the engine is automatically controlled first. First risk avoiding means for generating engine braking by controlling the brake hydraulic system to exert a braking force as necessary, and the determining means determines that there is a high risk of contact. The second danger avoiding means for automatically controlling the engine to generate the engine brake and controlling the brake hydraulic system to exert the braking force in the case of the above. Is The automatic braking of a vehicle is characterized in that the engine is controlled by a first engine control content, and the second danger avoiding means controls the engine by a second engine control content different from the first engine control content. apparatus. 2. The content of the first engine control is as follows.
The intake passage is closed and driven, and the fuel supply is cut off after the intake passage is fully closed. The second engine control content is to close the intake passage and cut off the fuel supply. The automatic braking device for a vehicle according to claim 1, wherein the automatic braking device is set as follows. 3. The own vehicle includes an automatic transmission, the first danger avoiding means controls the automatic transmission according to a first automatic shift control content, and the second danger avoiding means includes: The automatic braking device for a vehicle according to claim 1 or 2, wherein the automatic transmission is controlled by a second automatic transmission control content different from the first automatic transmission control content. 4. The automatic transmission includes a lock-up clutch, the first automatic shift control content is set to gently engage the lock-up clutch, and the second automatic shift control content is set. The automatic braking device for a vehicle according to claim 2 or 3, wherein the lock-up clutch is set to be immediately engaged. 5. The automatic transmission is configured such that a shift gear position can be fixed, and the first automatic shift control content is set to gently fix the shift gear position, and the second automatic shift control content is set. 5. The automatic braking device for a vehicle according to claim 3, wherein the content of the shift control is set so as to immediately fix the shift gear position. 6. The determining means determines that the degree of risk is low when it is determined that the distance between the vehicle and the front obstacle is continuously shortening, and When the distance between the vehicle and the front obstacle is judged to be discontinuously shortened, the dangerous movement is judged to be high. Any one of the above
An automatic braking device for a vehicle according to the item.