JPH05272370A - Automatic braking device for vehicle - Google Patents

Abstract

PURPOSE:To perform restoration action to normal control smoothly by generating an engine brake automatically when a vehicle has a possibility of contacting an obstacle, and releasing the engine brake in a restoration time in accordance with a transmission gear position when it has no possibility of contact. CONSTITUTION:An automatic transmission 16 connected to an engine 14 is controlled by an automatic transmission control unit 33 through solenoids 28, 32. In the meanwhile, a subsidiary throttle valve 38 disposed in an intake passage 44 of the engine 14 is controlled by an automatic brake control unit 49 through a subsidiary throttle valve controller 48 separately from a main throttle valve 34. In this case, in the automatic brake control unit 49, when a vehicle has a possibility of contacting an obstacle, an output of the engine 14 is reduced automatically to generated engine brake. In the meanwhile, when the possibility of contacting is eliminated, generation of the engine brake is released in compliance with a restoration time in accordance with a transmission gear position of the automatic transmission 16.

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 it is determined that there is a possibility of contact, the engine brake is forcibly activated regardless of the accelerator pedal depression amount to apply the engine braking force to each wheel, Those adapted to prevent contact are known.

[0003]

However, in the above-described conventional automatic braking device, when it is determined that the possibility of contact between the vehicle and the front obstacle is eliminated, the engine braking is stopped. Therefore, the normal throttle control, that is, basically, the throttle valve is opened and controlled in response to the depression of the accelerator pedal to return to the control state in which the engine output is changed. However, in such a return state, if the driver continues to depress the accelerator pedal, the engine speed rapidly increases in response to the return operation, and a so-called engine blow-up state occurs. Will be done. Such an engine blow-up state occurs even when the driver constantly depresses the accelerator pedal, and the driver feels a lot of discomfort, and improvement is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a normal engine even when the possibility that the vehicle may come into contact with a front obstacle due to the operation of the automatic engine brake is avoided. It is an object of the present invention to provide an automatic braking device for a vehicle that can smoothly achieve a return operation to control.

[0005]

In order to solve the above-mentioned problems and to 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 Contact possibility determination for determining whether or not there is a possibility that the own vehicle may contact the obstacle from the detection means for detecting the relative speed, the distance between the own vehicle and the obstacle detected by the detection means, and the relative speed Means and the automatic gear generation means for automatically reducing the engine output to generate engine brake when it is determined that there is a possibility of contact, and the shift gear position of the own vehicle When the gear position determining means and the contact possibility determining means determine that there is no possibility of contact, the engine braking is performed with a return time corresponding to the shift gear position determined by the gear position determining means. Automatically It is characterized by comprising a releasing means for releasing the engine braking state in means.

Further, in the automatic braking device for a vehicle according to the present invention as defined in claim 2, the releasing means is so reset that the shift gear position judged by the gear position judging means is a lower speed side gear position. It is characterized by setting a long time. Further, in the automatic braking device for a vehicle according to a third aspect of the present invention, the return time is changed and set according to the distance between the own vehicle and the obstacle. Further, in the vehicle automatic braking device according to the present invention according to claim 4, the return time is
It is characterized in that the distance is shortened as the distance increases.

According to a fifth aspect of the present invention, there is provided an automatic braking system for a vehicle according to the invention, wherein the return time is changed and set according to a relative speed between the own vehicle and an obstacle. I am trying. Further, in the vehicle automatic braking device according to the present invention of claim 6, the return time is
It is characterized in that it is extended as the relative speed increases. Further, in the automatic braking device for a vehicle according to a seventh aspect of the present invention, the releasing means returns the throttle valve to a throttle opening corresponding to an average value of the depression amount of the accelerator pedal. There is. Further, in the automatic braking device for a vehicle according to the present invention described in claim 8, the releasing means gradually increases the gain of the return control of the throttle valve.

[0008]

With the above construction, according to the invention described in claim 1, even if it is determined that the possibility that the vehicle may come into contact with the front obstacle is eliminated, the engine brake is first stopped. Then, the return time for returning to the normal throttle control is changed and set according to the shift gear position. As a result, the return time required to return to the normal throttle control is appropriately determined according to the position of the transmission gear, and this return operation is performed smoothly. According to the second aspect of the invention, the return time is set longer as the determined shift gear position is the lower gear position. As a result, it is possible to reliably prevent the engine from rising when returning to the normal throttle control when the low speed gear position is set.

Further, according to the invention described in claims 3 to 6, the return time can be set in a state in which the relationship with the obstacle is met, and the normal throttle control operation can be smoothly returned. Can be done. Further, according to the invention described in claims 7 and 8, the return operation of the throttle valve according to the depression amount of the accelerator pedal is achieved, and the return operation can be smoothly executed.

[0010]

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-described 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 type master cylinder 68 for pressurizing the brake oil is transmitted with 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 system configuration of the ABS is not 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 immediately 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 toward the vehicle in the same lane, a vehicle stopped in the same lane, or 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 sides 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, when the distance is about 10 m or less), or when traveling accuracy is not guaranteed due to scattering of the emitted laser light under bad weather conditions such as fog, 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 6. 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 one embodiment, as is apparent from the above description, the brake hydraulic system 5
As the brake pressure adjusting mechanism 54 provided in 2, automatic braking valve units 82FL, 82FR, 8 for automatic braking are provided.
Since 2RL and 82RR are arranged in series with ABS valve units 84FL, 84FR, 84RL, and 84RR for traction control, the automatic braking control operation is performed in order to balance the operation of both. As with the traction control operation, for example, it is set to be repeatedly activated at a cycle of 7 msec.

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).

Thereafter, in step S12, based on the various information read in step S10, various thresholds L ₀ , L ₀ ′, which are necessary to execute 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, the line C in FIG. 5 shows the third threshold line, and this third threshold line C is obtained when the vehicle as the front obstacle applies 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, the own vehicle and the forward obstacle are determined in step S14. 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,
The distance between the vehicle and the obstacle ahead (hereinafter, simply the distance
Call. ) L_x Is the above-mentioned threshold L₁ Is less than
To be judged. It is determined as NO in this step S16.
In other words, that is, the separation distance L _x Is the inequality L_x ≧ L₁ By
Within the specified range, it is still
If you don't have to reach the alarm buzzer 134
If judged, do not execute the automatic braking control operation
Since it is good, concrete execution of the braking force automatic activation routine
End this control procedure without setting
Wait for the next control procedure to start.

On the other hand, YES in step S16.
In other words, if the separation distance is inequality L _x <L ₁
If it is within the range defined by, and it is determined that the dangerous state is entered, the process proceeds to step S18, and the alarm buzzer 13
4 is ringing and notifies that the distance L _x of the front obstacle to the driver falls into critical condition. After this, step S2
At 0, it is determined whether the separation distance L _x is smaller than the threshold L ₀ ′. When NO is determined in this step S20, that is, the separation distance L _x is inequality L ₀ ′ ≦ L
_If it is within the range defined by _x <L ₁ and it is necessary to continue the alarm operation but it is not necessary to execute the automatic braking operation, the control procedure of this time is terminated, Wait for the start of the next control procedure set after 7 msec.

Here, if YES is determined in step S20, that is, the separation distance L _x is inequality L _x <L
_If it is within the range defined by ₀ ′ and it is determined that the automatic braking operation needs to be executed, the process proceeds to step S22, engine braking is generated in the engine 14, and the braking force by this engine braking is activated. To do so, an interrupt activation signal is output to the overall control unit (TCU) 113, and engine automatic braking control defined as an interrupt routine is activated here. The control procedure of this engine automatic braking control will be described later in detail.

After activating the engine automatic braking control in step S22, it is determined in subsequent step S24 whether the separation distance L _x is smaller than the threshold value L ₀ . If NO is determined in this step S24, that is, the separation distance L _x is inequality L ₀ ≦ L _x <L
_If it is within the range specified by ₀ ′ and it is judged that sufficient braking force is applied as a danger avoidance operation only by the braking force by the engine brake, the control procedure of this time is ended, and after 7 msec. Wait for the next control procedure to start.

On the other hand, in step S24 described above, Y
When it is judged as ES, that is, the separation distance L _x is the inequality L
_{In the} range defined by _x <L ₀ , and when it is determined that a strong braking force is required, the process proceeds to step S26,
A brake automatic braking control operation by the brake hydraulic system 52, which is defined as an interrupt routine, is activated. still,
The control procedure of this brake automatic braking operation will be described in detail later. Then, in step S28, the first flag F indicating that the brake automatic braking control operation is being executed.
Set 1 to "1" and wait for the next control procedure to start after 7 msec.

The brake automatic braking control operation in step S26 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. On the other hand, when it is determined NO in step S14 described above, that is,
When it is determined that the relative speed V _x is a negative value, and it is determined that the front obstacle is gradually moving away from the host vehicle, the braking force automatic 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 . This step S
If NO is determined in 30, that is, the separation distance L
_{When x} is within the range defined by the inequality L _x ≦ L ₂ , the relationship with the front obstacle is still in a dangerous state, and it is determined that the automatic braking control operation needs to be continued, the control is performed. Without specifically executing the power automatic release routine, the control procedure of this time is ended, and the activation of the next control procedure set after 7 msec is awaited. That is, this step S3
Even if it is determined to be NO in 0, if the engine automatic braking control is activated in advance in step S22 or step S26, or if the brake automatic braking control is activated, these continue to be executed. Become.

Further, 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 first flag F1 indicating that the automatic brake braking control operation is being executed is reset to "0" to indicate that the automatic brake braking control operation has been released. .. Then, in step S36, the separation distance L
_It is determined whether _x is larger than the threshold value L ₂ ′. When 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, but the strong braking force by the brake hydraulic system 52 is not sufficient. If it is determined that it is necessary to continue the engine automatic braking control operation although it is necessary, the control procedure of this time is terminated and the next control procedure set 7 msec later is waited for.

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 canceling operation is executed in which an engine automatic braking control canceling signal is output to the overall control unit (TCU) 113 to cancel the engine automatic braking control operation. The control procedure of the engine automatic braking control release operation will be described in detail later. 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, and an alarm operation release signal for releasing the alarm operation is output, that is, the alarm buzzer 134.
Then, the ringing operation in step 1 is stopped, the series of control procedures are terminated, and the start of the next control procedure set after 7 msec is awaited. In this way, the series of procedures of the automatic braking control operation is completed.

Next, the control procedure of the engine automatic braking control operation in step S22 described above will be described as an interrupt routine in the overall control unit (TCU) 113 with reference to FIG. First, when the engine automatic braking control operation is started in step S22, it is determined in step S22A whether "1" is set to the first flag F1 indicating that the brake automatic braking control is activated. To be done. If it is determined NO in step S22A, that is, if it is determined that the automatic brake braking control is not activated in advance, the engine brake control amount EBC (EBC () corresponding to the current travel range position or transmission gear position is obtained. (A detailed description will be given later.) Is executed.

That is, in the following step S22B, the traveling range position currently set in the automatic transmission 16 is determined based on the traveling range position information RI read in advance in step S10. This step S2
In 2B, the travel range position currently set in the automatic transmission 16 is "L" (that is, the transmission gear position is 1
If it is determined that the speed is fixed), step S2
In 2C, the engine brake control amount EBC is set to the minimum value (MIN). Then, the subsequent step S2
In 2D, this minimum engine brake control amount EB
At C, the sub throttle valve 38 is closed and driven via the sub throttle valve controller 48. Here, by setting the minimum engine brake control amount EBC, the sub-throttle valve controller 48 gradually activates the engine brake so that the intake passage 44 is closed at a gentle closing speed. Like sub-throttle valve 3
Drive eight.

On the other hand, in step S22B described above, the running range position currently set in the automatic transmission 16 is "S" (that is, the transmission gear position is the first speed or the second speed).
If it is determined that the speed is set), step S2
In 2E, the engine brake control amount EBC is set to an intermediate value (MED). Then, step S2 described above
2D, engine brake control amount EBC in the middle
Then, the sub throttle valve 38 is closed and driven via the sub throttle valve controller 48. 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 S22B described above, 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 that is optimum for the traveling state). If
In step S22F, the one-way clutch (not shown) in the automatic transmission 16 is fixed in order to prohibit the shift-up operation in the automatic transmission 16, in other words, in order to keep the current transmission gear position constant. That is, when the intake passage 44 is closed in the drive range "D", the vehicle normally operates by the action of the one-way clutch.
Inertia running state. 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 S22F, the one-way clutch is fixed to the current transmission gear position, the engine brake is surely activated, and the anxiety that the driver is pulled forward can be eliminated. Becomes

Then, in the following step S22G, 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 S22G that the transmission gear position is set to "first speed", the process proceeds to step S22C described above, the engine brake control amount EBC is set to the minimum value (MIN), and the step In S22D, the sub-throttle valve 38 is gently closed and driven with this minimum engine brake control amount EBC. On the other hand, in step S22G, when it is determined that the shift gear position is set to the "second speed", the process proceeds to step S22E described above, the engine brake control amount EBC is set to the intermediate value (MED), and the step S22D
Then, the sub-throttle valve 38 is closed at the normal closing speed with the engine brake control amount EBC in the middle.

On the other hand, if it is determined in step S22G that the transmission gear position is set to "third speed" or "fourth speed" (including overtop), engine brake control is performed in step S22H. The amount EBC is set to the maximum value (MAX), and thereafter, the process proceeds to step S22D described above, and the sub-throttle valve 38 is rapidly closed and driven with this maximum engine brake control amount EBC.

Here, in step S22A described above, if it is determined to be YES, that is, if it is determined that the brake automatic braking control is activated, irrespective of the current traveling range position or the current transmission gear position. , Executes a control procedure for setting the engine brake control amount EBC to the maximum value. That is, if YES is determined in step S22A, the process immediately jumps to step S22H, the engine brake control amount EBC is set to the maximum value (MAX), and the sub-throttle valve 38 is suddenly changed regardless of the gear position. It is closed to drive the engine brake strongly. That is, by activating such a powerful engine brake at the same time as the automatic brake control, the vehicle is decelerated with an extremely strong braking force as a whole, and a reliable risk avoiding operation is achieved.

As described above, in step S22D,
When the operation for closing and driving the sub-throttle valve 38 with the predetermined engine brake control amount EBC is executed, it is determined in the subsequent step S22I whether or not the engine automatic braking control release signal is output. If NO is determined in this step S22I, that is, if the above-mentioned step S38 is not executed and it is determined that the engine automatic braking control release signal is not output,
Returning to step S22A described above, the engine automatic braking control is activated again. On the other hand, if YES is determined in this step S22I, that is, if it is determined that the engine automatic braking control release signal is output in the above-mentioned step S38, the engine automatic braking control operation is ended and the series of these operations is terminated. The control procedure of the automatic engine braking control ends.

Next, referring to FIG. 7, the control procedure of the brake automatic braking control operation in step S26 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 automatic braking valve units 82FL, 82FR, 8 in the brake pressure adjusting mechanism 54 are firstly provided.
2RL and 82RR shutter valves 86FL and 8FL, respectively
6FR, 86RL, 86RR are all open,
Further, the pressure increasing valves 90FL, 90FR, 90RL, 90
RR and pressure reducing valve 94FL, 94FR, 94RL, 94
Both RRs are in a closed state. In this way, the brake pressure generated in the master cylinder 68 due to the depression of the brake pedal 50 is applied to the wheels 12FL, 12FR, 1
The manual braking operation can be executed by acting on 2RL and 12RR respectively.

When the brake automatic braking control operation is started in step S26 from the state before the execution of the brake automatic braking control operation as described above, in step S26A, 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 S26B, 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 step S26B, that is, the braking devices 60FL, 60FR, 6 are currently being used.
When it is determined that the brake pressure acting on 0RL and 60RR is insufficient, the pressure increasing valves 90FL, 90FR, 90RL and 90RR are opened and driven in step S26C, and the pressure reducing valves 94FL and 94FR are subsequently driven in step S26D. , 94RL, 94RR are driven to be closed. As a result, the accumulator 100FR, 1
The brake pressure accumulated in 00FR, 100RL, 100RR is applied to each wheel 12FL, 12FR, 12RL, 1
2RR braking device 60FL, 60FR, 60RL,
It acts on 60RR and a predetermined braking operation is executed.

On the other hand, if YES is determined in the above step S26B, that is, the braking device 6 is currently in progress.
If it is determined that the brake pressure acting on 0FL, 60FR, 60RL, and 60RR is sufficient, step S
26E, pressure increasing valves 90FL, 90FR, 90
RL and 90RR are closed and driven, and subsequent step S2
At 6F, 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 step S26D or step S26F is executed, the process proceeds to step S26G, where it is determined whether or not the brake automatic braking control release signal is output. If NO is determined in this step S26G, that is, the above-mentioned step S32 is not executed,
When it is determined that the brake automatic braking control release signal is not output, the process returns to step S26B described above,
From here, the automatic brake control is activated again. On the other hand, if YES is determined in step S26G, that is, if 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.

Next, with reference to FIGS. 8 to 11, the operation for canceling the automatic engine braking control in step S38 will be described in detail as a subroutine. First, when step S38 is executed and the engine automatic braking control release operation is started, the current transmission gear position GP is read in step S38A, and the subsequent step S3.
At 8B, the basic return time T1 is set according to the read transmission gear position GP. Here, in this embodiment, the basic return time T1 is set longer as the read shift gear position is the shift gear position on the low speed side, and conversely, the basic return time T1 is set on the shift gear position on the high speed side. It is set short. That is, the basic return time when the transmission gear position is determined to be the first speed and T1 _1, the basic return time when the transmission gear position is determined to be the second speed and T1 _2, the transmission gear position Let T1 ₃ be the basic return time when it is determined to be the third speed, and T1 ₄ be the basic return time when it is determined that the transmission gear position is the fourth speed.
1 ₁ , T1 ₂ , T1 ₃ and T1 ₄ are set to have a relationship defined by an inequality represented by T1 ₁ > T1 ₂ > T1 ₃ > T1 ₄ .

Next, in step S38C, the relative speed V1 described above is read, and in the subsequent step S38D, the read relative speed V1 is read as shown in FIG.
The first correction coefficient K1 is set according to Here, this first correction coefficient K1 is a number smaller than 1 and
As is clear from the above, it is set so that the slower the relative speed V1, the larger the value. That is, the slower the relative speed V1, the more the safety condition is guaranteed, and therefore the basic recovery time T1 described above is corrected to be short.

After that, the above-mentioned separation distance L _x is read in step S38E, and the subsequent step S38F.
In, as shown in FIG. 10, sets a second correction coefficient K2 corresponding to the read biting distance L _x. here,
The second correction coefficient K2 is defined by a number smaller than 1, and as is clear from FIG. 10, is set to have a smaller value as the separation distance L _x becomes longer. That is, the longer the separation distance L _x , the more secure the safety state is. Therefore, the basic recovery time T1 described above is corrected to be short.

Then, in the succeeding step S38G, the actual recovery time T2 is calculated from T2 = T1 × K1 × K2 and stored.

On the other hand, in step S38H, the current throttle opening, that is, the throttle opening TVOP at the time when it is determined that the dangerous state is resolved is read from the sub-throttle opening sensor 40, and in the subsequent step S38I, the sub-throttle is opened. The return target throttle opening TVOM in the valve 38 is set. Here, as shown in FIG. 11, the return target throttle opening TVOM is an average value of accelerator opening information read through the accelerator opening sensor 110 over a period before and after including a time when the dangerous state is resolved. Is calculated and the throttle opening corresponding to this average accelerator opening is returned to the target throttle opening TVOM
It is set to stipulate.

Thereafter, in step S38J, the throttle opening speed VTV is calculated from VTV = (TVOM-TVOP) / T2 and stored. Then, step S38
At K, the sub-throttle valve 38 is driven to open at this throttle opening speed VTV, and at step S38L, the above-described engine automatic braking control release signal is output to end the series of control procedures and return to the main routine.

As described above in detail, in this embodiment, the step S38 is started, so that the engine automatic braking control release signal is output substantially at the same time as the start, and the engine control is performed by the normal throttle. The control target state is restored, but at the time of returning to the throttle control state, the return target throttle opening TV is set at the return speed VTV based on the return time T1 corresponding to the current transmission gear position GP.
The sub throttle valve 38 is returned to the OM. In this way, for example, if the current transmission gear position GP is set to the low speed side, the return time T1 is set to be long, and thus the return speed VTV is set to be slow. As a result, it is assumed that the return target throttle opening TV
Even if the OM is set higher, the return operation is executed in a state where the return target throttle opening TVOM set to the higher target is gradually approached. Therefore, the engine speed rapidly increases, that is, the engine speed increases. The blow-up state is reliably avoided, and a smooth transition to the normal engine control state is achieved.

Further, in the above-mentioned embodiment, when the above-mentioned return time T1 is set, it is appropriately corrected according to the relationship with the front obstacle, specifically, the separation distance L _x and the relative speed V1. It is done like this. In this way
In a state where safety is ensured, a return operation to normal engine control is promoted as soon as possible, and execution of automatic braking control operation in a state where the driver's intention is ignored is terminated as soon as possible. Therefore, the driver's discomfort can be eased.

Further, in the above-described embodiment, the return target throttle opening TVOM is defined from the throttle opening based on the average value of the accelerator opening information over the period before and after this including the time when the dangerous state is eliminated. Is set. In this way, even if the driver repeatedly presses the accelerator pedal 46 during the execution of the automatic braking control operation, the target value is defined in a state where the maximum amount of depression / the minimum amount of depression is equalized. Properly restore the target throttle opening in a state that generally matches the driver's intention, and in a state in which the engine does not blow up due to the target throttle opening degree being set based on the maximum pedaling amount of the accelerator pedal 46. The degree will be set.

Further, 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 the dangerous state. In the control operation, first, an alarm operation is activated to notify the driver that the vehicle has entered a dangerous state with a front obstacle. Despite this notification operation, when the degree of danger to the front obstacle increases, first, the engine automatic braking control procedure is executed to activate the engine brake, and the speed of the vehicle is reduced. If the risk of a front obstacle also increases due to the activation of this engine brake, and the risk of collision increases, the automatic braking control procedure is executed to further activate the braking force by the braking device, and full braking is performed. To reduce the speed of the vehicle to a state where it is substantially stopped.

As described above, in this embodiment, in the automatic braking control, first, the engine brake is activated, and when the danger cannot be avoided by only the braking force by the engine brake, the braking force by the braking device is used. Is configured to apply full braking.
In this way, even if the automatic braking control is executed, initially only a gentle braking force by the engine brake is applied, so the driver does not feel a sense of deceleration, and the driver does not feel discomfort or shock / fear. It is possible to obtain the effect of reducing the risk of giving as much as possible. Also,
When the driver receives a shock or fear due to a sudden feeling of deceleration, the driver may panic and perform the wrong risk avoidance operation, and another risk may occur, but as described above,
In this embodiment, since the gradual deceleration operation is executed, the driver is less likely to be shocked / feared, and there is no risk of such another danger.

In this embodiment, the engine automatic braking control release signal is not immediately output,
After the release of the engine automatic braking control state is regulated, the accelerator pedal 46 is waited for a sufficient release, and specifically, the time after the release is measured, and the measured time has passed the reference time or more. If it is determined that the engine automatic braking control release signal is output, the engine automatic braking control release signal is output for the first time. In this way, even if the danger avoiding operation is automatically executed, the driver continues to depress the accelerator pedal 46 without noticing the execution of the danger avoiding operation. Even if the dangerous state is released by executing the above-described danger avoidance operation and the normal engine control state is restored, the accelerator pedal 46
An abrupt increase in engine speed (so-called engine blow-up) due to depression of the engine is reliably prevented, and the end of the above-described danger avoidance operation is executed without giving a sense of discomfort to the driver.

Further, when such an engine blow-up occurs, the vehicle speed may suddenly increase and the safety of the running condition may be impaired. However, as described above, this engine blow-up is surely performed. Since it is prevented, the traveling safety at the end of the danger avoidance operation is surely ensured.

Needless to say, the present invention is not limited to the configuration of the above-described embodiment, but can be variously modified without departing from the scope of the present invention. For example, in the above-described one embodiment, the vehicle A is described as including the automatic transmission 16, but the present invention is not limited to such a configuration and will be described as another embodiment below. In addition, it can be applied to a vehicle equipped with a manual transmission.

Further, in the above-described embodiment, when returning to the normal engine control state, the return target throttle opening TVOM is set from the average value of the accelerator opening information, and the return target throttle opening TVOM and the present value are set. It has been described that the return speed VTV is set by dividing the difference from the throttle opening TVOP of No. 2 by the actual return time T2. However, as will be shown in another embodiment below, from the average value of the accelerator opening information. Without setting the return target throttle opening TVOM, a predetermined gain G is added to the current throttle opening TVOP.
The target return throttle opening TVO
It may be configured to set M.

The configuration of another embodiment according to the present invention will be described below with reference to FIGS. 12 and 13. In this embodiment, step S3 in the one embodiment described above.
Since a part of the engine automatic braking control release procedure in 8 is configured differently, description will be given with only the different part taken out, and the same part (same step) will be denoted by the same reference numeral. The description is omitted.

First, step S38 in this embodiment.
In step S38 in the above-described embodiment,
In the plurality of control procedures constituting the above, steps S38A to S38H, and steps S38K and S38L are the same, so description thereof will be omitted here. Then, in step S38H described above, when the current throttle opening TVOP is read, in this embodiment, the process proceeds to step S38M, where the elapsed time from the time when this step S38 is activated, that is, the dangerous state. The elapsed time t from when is solved is measured. After that, in the subsequent step S38N, the value of the gain G is set according to the actual return time T2 described above.

Here, in this embodiment, the value of the gain G is defined as a percentage, and as shown in FIG. 13, the actual recovery time T2 is divided into a predetermined number n, and the divided predetermined number of periods. The gain values are set so as to gradually increase in the order of No., that is, in the m-th divided period, the gain value becomes 100 ÷ n × (m−1).
Specifically, in the first divided period (that is, m = 1) divided into n = 10, the gain value is 0 {= 100 ÷ 1.
0 × (1-1)}% and set for the next split period (ie,
In m = 2), 10 {= 100/10 × (2-
1)}%, and the next divided period (that is, m = 3)
Is set to 20 {= 100 ÷ 10 × (3-1)}%, and the gain value is gradually increased in this way, and in the tenth (that is, the last) divided period,
It is set to 0 {= 100 ÷ 10 × (10-1)}%.

After the value of the gain G is set in step S38N in this way, in the subsequent step S38O, the divided period corresponding to the elapsed time t is determined,
The value of the gain G in this divided period is read. Thereafter, in step S38P, the return speed VTV is calculated from VTV = VTOP × G / 100, and step S38 in the above-described embodiment is executed.
Similar to K, the sub-throttle valve 38 is closed and driven at the return speed VTV as the result of this calculation. After this, although not shown, as in the above-described embodiment, step S38.
At L, output the engine automatic braking control release signal,
The series of control procedures is terminated, and the original main routine is returned to.

By constructing another embodiment in this way,
As shown by the solid line in FIG. 13, the throttle opening degree is gradually opened and driven over the set actual return time T2, while changing in accordance with the current accelerator opening degree. It is possible to obtain the same effect as that of the above embodiment.

[0086]

As described in detail above, the automatic braking system for a vehicle according to the present invention detects the distance and relative speed between the vehicle and the obstacle. Detecting means, a contact possibility determining means for determining whether or not the own vehicle may contact the obstacle from the distance and relative speed between the own vehicle and the obstacle detected by the detecting means, and this determination When it is determined that there is a possibility of contact by means,
There is a possibility of contact by the engine brake automatic generation means for automatically reducing the engine output to generate the engine brake, the gear position determination means for determining the shift gear position of the own vehicle, and the contact possibility determination means. When it is determined that the engine brake generation state has disappeared, a release means for releasing the engine brake generation state in the engine brake automatic generation means with a return time corresponding to the transmission gear position determined by the gear position determination means is provided. I am trying.

Further, in the vehicle automatic braking device according to the present invention, the releasing means sets the return time longer as the shift gear position determined by the gear position determining means is the lower gear position. Is characterized by.
Further, in the automatic braking device for a vehicle according to a third aspect of the present invention, the return time is changed and set according to the distance between the own vehicle and the obstacle. Further, in the vehicle automatic braking device according to the present invention, the return time is shortened as the distance increases.

Further, in the vehicle automatic braking apparatus according to the present invention, the return time is changed and set according to the relative speed between the own vehicle and the obstacle. Further, in the vehicle automatic braking device according to the present invention, the return time is extended as the relative speed increases. Also, in the vehicle automatic braking device according to the present invention, the releasing means is
It is characterized in that the throttle valve is returned to the throttle opening corresponding to the average value of the depression amount of the accelerator pedal. Further, in the automatic braking device for a vehicle according to the present invention, the releasing means gradually increases the gain of the return control of the throttle valve.

Therefore, according to the present invention, the return operation to the normal engine control can be smoothly achieved even in the state where the possibility of the own vehicle coming into contact with the front obstacle due to the operation of the automatic engine braking is avoided. An automatic braking system for vehicles that can do this will be provided.

[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 engine automatic braking control operation in step S22.

FIG. 7 is a flowchart showing a control procedure of a brake automatic braking control operation in step S26.

FIG. 8 is a flowchart showing a control procedure of an engine automatic braking control release operation in step S38.

FIG. 9 is a diagram showing a correlation between a relative speed and a first correction coefficient in step S38C.

FIG. 10 is a diagram showing a correlation between a separation distance and a second correction coefficient in step S38E.

FIG. 11 is a diagram showing a manner of setting a return target throttle opening in step S38I.

FIG. 12 is a flowchart showing a control procedure of an engine automatic braking release operation in another embodiment of the vehicle automatic braking device according to the present invention.

13 is a diagram showing a manner of setting the value of the gain G according to the actual return time in step S38N shown in FIG.

[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 60 braking device 72 brake piping, 82 automatic braking valve unit 84 ABS valve unit 116 detection mechanism Is.

Claims (8)

[Claims] 1. A detecting 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 detecting means, A contact possibility determination unit that determines whether or not there is a possibility of contact with an obstacle, and if this determination unit determines that there is a possibility of contact, the engine output is automatically reduced to generate engine braking. When the automatic braking means for making an engine brake, the gear position judging means for judging the shift gear position of the vehicle, and the contact possibility judging means judge that the possibility of contact disappears, the gear position judging means An automatic braking device for a vehicle, comprising: a release unit that releases an engine brake generation state in the engine brake automatic generation unit with a return time corresponding to a determined shift gear position. 2. The vehicle according to claim 1, wherein the releasing unit sets the return time longer as the shift gear position determined by the gear position determining unit is a lower gear position. Automatic braking system. 3. The automatic braking device for a vehicle according to claim 2, wherein the return time is changed and set according to a distance between the own vehicle and an obstacle. 4. The automatic braking device for a vehicle according to claim 4, wherein the return time is shortened as the distance increases. 5. The vehicle automatic braking device according to claim 2, wherein the return time is changed and set according to a relative speed between the own vehicle and the obstacle. 6. The automatic braking device for a vehicle according to claim 5, wherein the return time is extended as the relative speed increases. 7. The automatic braking device for a vehicle according to claim 1, wherein the releasing means returns the throttle valve to a throttle opening corresponding to an average value of the depression amount of the accelerator pedal. 8. The automatic braking device for a vehicle according to claim 7, wherein the releasing means gradually increases the gain of the return control of the throttle valve.